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bcea3f96 | 1 | // SPDX-License-Identifier: GPL-2.0 |
16444a8a ACM |
2 | /* |
3 | * Infrastructure for profiling code inserted by 'gcc -pg'. | |
4 | * | |
5 | * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> | |
6 | * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com> | |
7 | * | |
8 | * Originally ported from the -rt patch by: | |
9 | * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com> | |
10 | * | |
11 | * Based on code in the latency_tracer, that is: | |
12 | * | |
13 | * Copyright (C) 2004-2006 Ingo Molnar | |
6d49e352 | 14 | * Copyright (C) 2004 Nadia Yvette Chambers |
16444a8a ACM |
15 | */ |
16 | ||
3d083395 SR |
17 | #include <linux/stop_machine.h> |
18 | #include <linux/clocksource.h> | |
29930025 | 19 | #include <linux/sched/task.h> |
3d083395 | 20 | #include <linux/kallsyms.h> |
17911ff3 | 21 | #include <linux/security.h> |
5072c59f | 22 | #include <linux/seq_file.h> |
8434dc93 | 23 | #include <linux/tracefs.h> |
3d083395 | 24 | #include <linux/hardirq.h> |
2d8b820b | 25 | #include <linux/kthread.h> |
5072c59f | 26 | #include <linux/uaccess.h> |
5855fead | 27 | #include <linux/bsearch.h> |
56d82e00 | 28 | #include <linux/module.h> |
2d8b820b | 29 | #include <linux/ftrace.h> |
b0fc494f | 30 | #include <linux/sysctl.h> |
5a0e3ad6 | 31 | #include <linux/slab.h> |
5072c59f | 32 | #include <linux/ctype.h> |
68950619 | 33 | #include <linux/sort.h> |
3d083395 | 34 | #include <linux/list.h> |
59df055f | 35 | #include <linux/hash.h> |
3f379b03 | 36 | #include <linux/rcupdate.h> |
fabe38ab | 37 | #include <linux/kprobes.h> |
3d083395 | 38 | |
ad8d75ff | 39 | #include <trace/events/sched.h> |
8aef2d28 | 40 | |
b80f0f6c | 41 | #include <asm/sections.h> |
2af15d6a | 42 | #include <asm/setup.h> |
395a59d0 | 43 | |
3306fc4a | 44 | #include "ftrace_internal.h" |
0706f1c4 | 45 | #include "trace_output.h" |
bac429f0 | 46 | #include "trace_stat.h" |
16444a8a | 47 | |
e11b521a | 48 | /* Flags that do not get reset */ |
6ce2c04f SRG |
49 | #define FTRACE_NOCLEAR_FLAGS (FTRACE_FL_DISABLED | FTRACE_FL_TOUCHED | \ |
50 | FTRACE_FL_MODIFIED) | |
e11b521a | 51 | |
b39181f7 SRG |
52 | #define FTRACE_INVALID_FUNCTION "__ftrace_invalid_address__" |
53 | ||
6912896e | 54 | #define FTRACE_WARN_ON(cond) \ |
0778d9ad SR |
55 | ({ \ |
56 | int ___r = cond; \ | |
57 | if (WARN_ON(___r)) \ | |
6912896e | 58 | ftrace_kill(); \ |
0778d9ad SR |
59 | ___r; \ |
60 | }) | |
6912896e SR |
61 | |
62 | #define FTRACE_WARN_ON_ONCE(cond) \ | |
0778d9ad SR |
63 | ({ \ |
64 | int ___r = cond; \ | |
65 | if (WARN_ON_ONCE(___r)) \ | |
6912896e | 66 | ftrace_kill(); \ |
0778d9ad SR |
67 | ___r; \ |
68 | }) | |
6912896e | 69 | |
8fc0c701 | 70 | /* hash bits for specific function selection */ |
33dc9b12 SR |
71 | #define FTRACE_HASH_DEFAULT_BITS 10 |
72 | #define FTRACE_HASH_MAX_BITS 12 | |
8fc0c701 | 73 | |
f04f24fb | 74 | #ifdef CONFIG_DYNAMIC_FTRACE |
33b7f99c SRRH |
75 | #define INIT_OPS_HASH(opsname) \ |
76 | .func_hash = &opsname.local_hash, \ | |
77 | .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock), | |
f04f24fb | 78 | #else |
33b7f99c | 79 | #define INIT_OPS_HASH(opsname) |
f04f24fb MH |
80 | #endif |
81 | ||
a0572f68 SRV |
82 | enum { |
83 | FTRACE_MODIFY_ENABLE_FL = (1 << 0), | |
84 | FTRACE_MODIFY_MAY_SLEEP_FL = (1 << 1), | |
85 | }; | |
86 | ||
3306fc4a | 87 | struct ftrace_ops ftrace_list_end __read_mostly = { |
2f5f6ad9 | 88 | .func = ftrace_stub, |
a25d036d | 89 | .flags = FTRACE_OPS_FL_STUB, |
33b7f99c | 90 | INIT_OPS_HASH(ftrace_list_end) |
2f5f6ad9 SR |
91 | }; |
92 | ||
4eebcc81 SR |
93 | /* ftrace_enabled is a method to turn ftrace on or off */ |
94 | int ftrace_enabled __read_mostly; | |
5d79fa0d | 95 | static int __maybe_unused last_ftrace_enabled; |
b0fc494f | 96 | |
2f5f6ad9 SR |
97 | /* Current function tracing op */ |
98 | struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end; | |
405e1d83 SRRH |
99 | /* What to set function_trace_op to */ |
100 | static struct ftrace_ops *set_function_trace_op; | |
60a7ecf4 | 101 | |
345ddcc8 | 102 | static bool ftrace_pids_enabled(struct ftrace_ops *ops) |
e3eea140 | 103 | { |
345ddcc8 SRRH |
104 | struct trace_array *tr; |
105 | ||
106 | if (!(ops->flags & FTRACE_OPS_FL_PID) || !ops->private) | |
107 | return false; | |
108 | ||
109 | tr = ops->private; | |
110 | ||
b3b1e6ed | 111 | return tr->function_pids != NULL || tr->function_no_pids != NULL; |
e3eea140 SRRH |
112 | } |
113 | ||
114 | static void ftrace_update_trampoline(struct ftrace_ops *ops); | |
115 | ||
4eebcc81 SR |
116 | /* |
117 | * ftrace_disabled is set when an anomaly is discovered. | |
118 | * ftrace_disabled is much stronger than ftrace_enabled. | |
119 | */ | |
120 | static int ftrace_disabled __read_mostly; | |
121 | ||
3306fc4a | 122 | DEFINE_MUTEX(ftrace_lock); |
b0fc494f | 123 | |
3306fc4a | 124 | struct ftrace_ops __rcu *ftrace_ops_list __read_mostly = &ftrace_list_end; |
16444a8a | 125 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; |
3306fc4a | 126 | struct ftrace_ops global_ops; |
16444a8a | 127 | |
50c69781 | 128 | /* Defined by vmlinux.lds.h see the comment above arch_ftrace_ops_list_func for details */ |
34cdd18b SRV |
129 | void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, |
130 | struct ftrace_ops *op, struct ftrace_regs *fregs); | |
b848914c | 131 | |
cbad0fb2 MR |
132 | #ifdef CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS |
133 | /* | |
134 | * Stub used to invoke the list ops without requiring a separate trampoline. | |
135 | */ | |
136 | const struct ftrace_ops ftrace_list_ops = { | |
137 | .func = ftrace_ops_list_func, | |
138 | .flags = FTRACE_OPS_FL_STUB, | |
139 | }; | |
140 | ||
141 | static void ftrace_ops_nop_func(unsigned long ip, unsigned long parent_ip, | |
142 | struct ftrace_ops *op, | |
143 | struct ftrace_regs *fregs) | |
144 | { | |
145 | /* do nothing */ | |
146 | } | |
147 | ||
148 | /* | |
149 | * Stub used when a call site is disabled. May be called transiently by threads | |
150 | * which have made it into ftrace_caller but haven't yet recovered the ops at | |
151 | * the point the call site is disabled. | |
152 | */ | |
153 | const struct ftrace_ops ftrace_nop_ops = { | |
154 | .func = ftrace_ops_nop_func, | |
155 | .flags = FTRACE_OPS_FL_STUB, | |
156 | }; | |
157 | #endif | |
158 | ||
f04f24fb MH |
159 | static inline void ftrace_ops_init(struct ftrace_ops *ops) |
160 | { | |
161 | #ifdef CONFIG_DYNAMIC_FTRACE | |
162 | if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) { | |
33b7f99c SRRH |
163 | mutex_init(&ops->local_hash.regex_lock); |
164 | ops->func_hash = &ops->local_hash; | |
f04f24fb MH |
165 | ops->flags |= FTRACE_OPS_FL_INITIALIZED; |
166 | } | |
167 | #endif | |
168 | } | |
169 | ||
2f5f6ad9 | 170 | static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip, |
d19ad077 | 171 | struct ftrace_ops *op, struct ftrace_regs *fregs) |
df4fc315 | 172 | { |
345ddcc8 | 173 | struct trace_array *tr = op->private; |
717e3f5e | 174 | int pid; |
345ddcc8 | 175 | |
717e3f5e SRV |
176 | if (tr) { |
177 | pid = this_cpu_read(tr->array_buffer.data->ftrace_ignore_pid); | |
178 | if (pid == FTRACE_PID_IGNORE) | |
179 | return; | |
180 | if (pid != FTRACE_PID_TRACE && | |
181 | pid != current->pid) | |
182 | return; | |
183 | } | |
df4fc315 | 184 | |
d19ad077 | 185 | op->saved_func(ip, parent_ip, op, fregs); |
df4fc315 SR |
186 | } |
187 | ||
405e1d83 SRRH |
188 | static void ftrace_sync_ipi(void *data) |
189 | { | |
190 | /* Probably not needed, but do it anyway */ | |
191 | smp_rmb(); | |
192 | } | |
193 | ||
00ccbf2f SRRH |
194 | static ftrace_func_t ftrace_ops_get_list_func(struct ftrace_ops *ops) |
195 | { | |
196 | /* | |
78a01feb | 197 | * If this is a dynamic or RCU ops, or we force list func, |
00ccbf2f SRRH |
198 | * then it needs to call the list anyway. |
199 | */ | |
b3a88803 PZ |
200 | if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_RCU) || |
201 | FTRACE_FORCE_LIST_FUNC) | |
00ccbf2f SRRH |
202 | return ftrace_ops_list_func; |
203 | ||
204 | return ftrace_ops_get_func(ops); | |
205 | } | |
206 | ||
2b499381 SR |
207 | static void update_ftrace_function(void) |
208 | { | |
209 | ftrace_func_t func; | |
210 | ||
f7aad4e1 SRRH |
211 | /* |
212 | * Prepare the ftrace_ops that the arch callback will use. | |
213 | * If there's only one ftrace_ops registered, the ftrace_ops_list | |
214 | * will point to the ops we want. | |
215 | */ | |
f86f4180 CZ |
216 | set_function_trace_op = rcu_dereference_protected(ftrace_ops_list, |
217 | lockdep_is_held(&ftrace_lock)); | |
f7aad4e1 SRRH |
218 | |
219 | /* If there's no ftrace_ops registered, just call the stub function */ | |
f86f4180 | 220 | if (set_function_trace_op == &ftrace_list_end) { |
f7aad4e1 SRRH |
221 | func = ftrace_stub; |
222 | ||
cdbe61bf SR |
223 | /* |
224 | * If we are at the end of the list and this ops is | |
4740974a SR |
225 | * recursion safe and not dynamic and the arch supports passing ops, |
226 | * then have the mcount trampoline call the function directly. | |
cdbe61bf | 227 | */ |
f86f4180 CZ |
228 | } else if (rcu_dereference_protected(ftrace_ops_list->next, |
229 | lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) { | |
00ccbf2f | 230 | func = ftrace_ops_get_list_func(ftrace_ops_list); |
f7aad4e1 | 231 | |
2f5f6ad9 SR |
232 | } else { |
233 | /* Just use the default ftrace_ops */ | |
405e1d83 | 234 | set_function_trace_op = &ftrace_list_end; |
b848914c | 235 | func = ftrace_ops_list_func; |
2f5f6ad9 | 236 | } |
2b499381 | 237 | |
5f8bf2d2 SRRH |
238 | update_function_graph_func(); |
239 | ||
405e1d83 SRRH |
240 | /* If there's no change, then do nothing more here */ |
241 | if (ftrace_trace_function == func) | |
242 | return; | |
243 | ||
244 | /* | |
245 | * If we are using the list function, it doesn't care | |
246 | * about the function_trace_ops. | |
247 | */ | |
248 | if (func == ftrace_ops_list_func) { | |
249 | ftrace_trace_function = func; | |
250 | /* | |
251 | * Don't even bother setting function_trace_ops, | |
252 | * it would be racy to do so anyway. | |
253 | */ | |
254 | return; | |
255 | } | |
256 | ||
257 | #ifndef CONFIG_DYNAMIC_FTRACE | |
258 | /* | |
259 | * For static tracing, we need to be a bit more careful. | |
260 | * The function change takes affect immediately. Thus, | |
fdda88d3 | 261 | * we need to coordinate the setting of the function_trace_ops |
405e1d83 SRRH |
262 | * with the setting of the ftrace_trace_function. |
263 | * | |
264 | * Set the function to the list ops, which will call the | |
265 | * function we want, albeit indirectly, but it handles the | |
266 | * ftrace_ops and doesn't depend on function_trace_op. | |
267 | */ | |
268 | ftrace_trace_function = ftrace_ops_list_func; | |
269 | /* | |
270 | * Make sure all CPUs see this. Yes this is slow, but static | |
271 | * tracing is slow and nasty to have enabled. | |
272 | */ | |
e5a971d7 | 273 | synchronize_rcu_tasks_rude(); |
405e1d83 SRRH |
274 | /* Now all cpus are using the list ops. */ |
275 | function_trace_op = set_function_trace_op; | |
276 | /* Make sure the function_trace_op is visible on all CPUs */ | |
277 | smp_wmb(); | |
278 | /* Nasty way to force a rmb on all cpus */ | |
279 | smp_call_function(ftrace_sync_ipi, NULL, 1); | |
280 | /* OK, we are all set to update the ftrace_trace_function now! */ | |
281 | #endif /* !CONFIG_DYNAMIC_FTRACE */ | |
282 | ||
491d0dcf | 283 | ftrace_trace_function = func; |
491d0dcf SR |
284 | } |
285 | ||
f86f4180 CZ |
286 | static void add_ftrace_ops(struct ftrace_ops __rcu **list, |
287 | struct ftrace_ops *ops) | |
3d083395 | 288 | { |
f86f4180 CZ |
289 | rcu_assign_pointer(ops->next, *list); |
290 | ||
16444a8a | 291 | /* |
b848914c | 292 | * We are entering ops into the list but another |
16444a8a ACM |
293 | * CPU might be walking that list. We need to make sure |
294 | * the ops->next pointer is valid before another CPU sees | |
b848914c | 295 | * the ops pointer included into the list. |
16444a8a | 296 | */ |
2b499381 | 297 | rcu_assign_pointer(*list, ops); |
16444a8a ACM |
298 | } |
299 | ||
f86f4180 CZ |
300 | static int remove_ftrace_ops(struct ftrace_ops __rcu **list, |
301 | struct ftrace_ops *ops) | |
16444a8a | 302 | { |
16444a8a | 303 | struct ftrace_ops **p; |
16444a8a ACM |
304 | |
305 | /* | |
3d083395 SR |
306 | * If we are removing the last function, then simply point |
307 | * to the ftrace_stub. | |
16444a8a | 308 | */ |
f86f4180 CZ |
309 | if (rcu_dereference_protected(*list, |
310 | lockdep_is_held(&ftrace_lock)) == ops && | |
311 | rcu_dereference_protected(ops->next, | |
312 | lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) { | |
2b499381 | 313 | *list = &ftrace_list_end; |
e6ea44e9 | 314 | return 0; |
16444a8a ACM |
315 | } |
316 | ||
2b499381 | 317 | for (p = list; *p != &ftrace_list_end; p = &(*p)->next) |
16444a8a ACM |
318 | if (*p == ops) |
319 | break; | |
320 | ||
e6ea44e9 SR |
321 | if (*p != ops) |
322 | return -1; | |
16444a8a ACM |
323 | |
324 | *p = (*p)->next; | |
2b499381 SR |
325 | return 0; |
326 | } | |
16444a8a | 327 | |
f3bea491 SRRH |
328 | static void ftrace_update_trampoline(struct ftrace_ops *ops); |
329 | ||
3306fc4a | 330 | int __register_ftrace_function(struct ftrace_ops *ops) |
2b499381 | 331 | { |
591dffda SRRH |
332 | if (ops->flags & FTRACE_OPS_FL_DELETED) |
333 | return -EINVAL; | |
334 | ||
b848914c SR |
335 | if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED)) |
336 | return -EBUSY; | |
337 | ||
06aeaaea | 338 | #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS |
08f6fba5 SR |
339 | /* |
340 | * If the ftrace_ops specifies SAVE_REGS, then it only can be used | |
341 | * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set. | |
342 | * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant. | |
343 | */ | |
344 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS && | |
345 | !(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)) | |
346 | return -EINVAL; | |
347 | ||
348 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED) | |
349 | ops->flags |= FTRACE_OPS_FL_SAVE_REGS; | |
350 | #endif | |
7162431d MB |
351 | if (!ftrace_enabled && (ops->flags & FTRACE_OPS_FL_PERMANENT)) |
352 | return -EBUSY; | |
08f6fba5 | 353 | |
a20deb3a | 354 | if (!is_kernel_core_data((unsigned long)ops)) |
cdbe61bf SR |
355 | ops->flags |= FTRACE_OPS_FL_DYNAMIC; |
356 | ||
ba27f2bc | 357 | add_ftrace_ops(&ftrace_ops_list, ops); |
b848914c | 358 | |
e3eea140 SRRH |
359 | /* Always save the function, and reset at unregistering */ |
360 | ops->saved_func = ops->func; | |
361 | ||
345ddcc8 | 362 | if (ftrace_pids_enabled(ops)) |
e3eea140 SRRH |
363 | ops->func = ftrace_pid_func; |
364 | ||
f3bea491 SRRH |
365 | ftrace_update_trampoline(ops); |
366 | ||
2b499381 SR |
367 | if (ftrace_enabled) |
368 | update_ftrace_function(); | |
369 | ||
370 | return 0; | |
371 | } | |
372 | ||
3306fc4a | 373 | int __unregister_ftrace_function(struct ftrace_ops *ops) |
2b499381 SR |
374 | { |
375 | int ret; | |
376 | ||
b848914c SR |
377 | if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED))) |
378 | return -EBUSY; | |
379 | ||
ba27f2bc | 380 | ret = remove_ftrace_ops(&ftrace_ops_list, ops); |
b848914c | 381 | |
2b499381 SR |
382 | if (ret < 0) |
383 | return ret; | |
b848914c | 384 | |
491d0dcf SR |
385 | if (ftrace_enabled) |
386 | update_ftrace_function(); | |
16444a8a | 387 | |
e3eea140 SRRH |
388 | ops->func = ops->saved_func; |
389 | ||
e6ea44e9 | 390 | return 0; |
3d083395 SR |
391 | } |
392 | ||
df4fc315 SR |
393 | static void ftrace_update_pid_func(void) |
394 | { | |
e3eea140 SRRH |
395 | struct ftrace_ops *op; |
396 | ||
491d0dcf | 397 | /* Only do something if we are tracing something */ |
df4fc315 | 398 | if (ftrace_trace_function == ftrace_stub) |
10dd3ebe | 399 | return; |
df4fc315 | 400 | |
e3eea140 SRRH |
401 | do_for_each_ftrace_op(op, ftrace_ops_list) { |
402 | if (op->flags & FTRACE_OPS_FL_PID) { | |
345ddcc8 SRRH |
403 | op->func = ftrace_pids_enabled(op) ? |
404 | ftrace_pid_func : op->saved_func; | |
e3eea140 SRRH |
405 | ftrace_update_trampoline(op); |
406 | } | |
407 | } while_for_each_ftrace_op(op); | |
408 | ||
491d0dcf | 409 | update_ftrace_function(); |
df4fc315 SR |
410 | } |
411 | ||
493762fc SR |
412 | #ifdef CONFIG_FUNCTION_PROFILER |
413 | struct ftrace_profile { | |
414 | struct hlist_node node; | |
415 | unsigned long ip; | |
416 | unsigned long counter; | |
0706f1c4 SR |
417 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
418 | unsigned long long time; | |
e330b3bc | 419 | unsigned long long time_squared; |
0706f1c4 | 420 | #endif |
8fc0c701 SR |
421 | }; |
422 | ||
493762fc SR |
423 | struct ftrace_profile_page { |
424 | struct ftrace_profile_page *next; | |
425 | unsigned long index; | |
426 | struct ftrace_profile records[]; | |
d61f82d0 SR |
427 | }; |
428 | ||
cafb168a SR |
429 | struct ftrace_profile_stat { |
430 | atomic_t disabled; | |
431 | struct hlist_head *hash; | |
432 | struct ftrace_profile_page *pages; | |
433 | struct ftrace_profile_page *start; | |
434 | struct tracer_stat stat; | |
435 | }; | |
436 | ||
493762fc SR |
437 | #define PROFILE_RECORDS_SIZE \ |
438 | (PAGE_SIZE - offsetof(struct ftrace_profile_page, records)) | |
5072c59f | 439 | |
493762fc SR |
440 | #define PROFILES_PER_PAGE \ |
441 | (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile)) | |
3d083395 | 442 | |
fb9fb015 SR |
443 | static int ftrace_profile_enabled __read_mostly; |
444 | ||
445 | /* ftrace_profile_lock - synchronize the enable and disable of the profiler */ | |
bac429f0 SR |
446 | static DEFINE_MUTEX(ftrace_profile_lock); |
447 | ||
cafb168a | 448 | static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats); |
493762fc | 449 | |
20079ebe NK |
450 | #define FTRACE_PROFILE_HASH_BITS 10 |
451 | #define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS) | |
493762fc | 452 | |
bac429f0 SR |
453 | static void * |
454 | function_stat_next(void *v, int idx) | |
455 | { | |
493762fc SR |
456 | struct ftrace_profile *rec = v; |
457 | struct ftrace_profile_page *pg; | |
bac429f0 | 458 | |
493762fc | 459 | pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK); |
bac429f0 SR |
460 | |
461 | again: | |
0296e425 LZ |
462 | if (idx != 0) |
463 | rec++; | |
464 | ||
bac429f0 SR |
465 | if ((void *)rec >= (void *)&pg->records[pg->index]) { |
466 | pg = pg->next; | |
467 | if (!pg) | |
468 | return NULL; | |
469 | rec = &pg->records[0]; | |
493762fc SR |
470 | if (!rec->counter) |
471 | goto again; | |
bac429f0 SR |
472 | } |
473 | ||
bac429f0 SR |
474 | return rec; |
475 | } | |
476 | ||
477 | static void *function_stat_start(struct tracer_stat *trace) | |
478 | { | |
cafb168a SR |
479 | struct ftrace_profile_stat *stat = |
480 | container_of(trace, struct ftrace_profile_stat, stat); | |
481 | ||
482 | if (!stat || !stat->start) | |
483 | return NULL; | |
484 | ||
485 | return function_stat_next(&stat->start->records[0], 0); | |
bac429f0 SR |
486 | } |
487 | ||
0706f1c4 SR |
488 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
489 | /* function graph compares on total time */ | |
80042c8f | 490 | static int function_stat_cmp(const void *p1, const void *p2) |
0706f1c4 | 491 | { |
80042c8f AS |
492 | const struct ftrace_profile *a = p1; |
493 | const struct ftrace_profile *b = p2; | |
0706f1c4 SR |
494 | |
495 | if (a->time < b->time) | |
496 | return -1; | |
497 | if (a->time > b->time) | |
498 | return 1; | |
499 | else | |
500 | return 0; | |
501 | } | |
502 | #else | |
503 | /* not function graph compares against hits */ | |
80042c8f | 504 | static int function_stat_cmp(const void *p1, const void *p2) |
bac429f0 | 505 | { |
80042c8f AS |
506 | const struct ftrace_profile *a = p1; |
507 | const struct ftrace_profile *b = p2; | |
bac429f0 SR |
508 | |
509 | if (a->counter < b->counter) | |
510 | return -1; | |
511 | if (a->counter > b->counter) | |
512 | return 1; | |
513 | else | |
514 | return 0; | |
515 | } | |
0706f1c4 | 516 | #endif |
bac429f0 SR |
517 | |
518 | static int function_stat_headers(struct seq_file *m) | |
519 | { | |
0706f1c4 | 520 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
fa6f0cc7 RV |
521 | seq_puts(m, " Function " |
522 | "Hit Time Avg s^2\n" | |
523 | " -------- " | |
524 | "--- ---- --- ---\n"); | |
0706f1c4 | 525 | #else |
fa6f0cc7 RV |
526 | seq_puts(m, " Function Hit\n" |
527 | " -------- ---\n"); | |
0706f1c4 | 528 | #endif |
bac429f0 SR |
529 | return 0; |
530 | } | |
531 | ||
532 | static int function_stat_show(struct seq_file *m, void *v) | |
533 | { | |
493762fc | 534 | struct ftrace_profile *rec = v; |
bac429f0 | 535 | char str[KSYM_SYMBOL_LEN]; |
3aaba20f | 536 | int ret = 0; |
0706f1c4 | 537 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b SR |
538 | static struct trace_seq s; |
539 | unsigned long long avg; | |
e330b3bc | 540 | unsigned long long stddev; |
0706f1c4 | 541 | #endif |
3aaba20f LZ |
542 | mutex_lock(&ftrace_profile_lock); |
543 | ||
544 | /* we raced with function_profile_reset() */ | |
545 | if (unlikely(rec->counter == 0)) { | |
546 | ret = -EBUSY; | |
547 | goto out; | |
548 | } | |
bac429f0 | 549 | |
8e436ca0 | 550 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e31f7939 | 551 | avg = div64_ul(rec->time, rec->counter); |
8e436ca0 UT |
552 | if (tracing_thresh && (avg < tracing_thresh)) |
553 | goto out; | |
554 | #endif | |
555 | ||
bac429f0 | 556 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); |
0706f1c4 SR |
557 | seq_printf(m, " %-30.30s %10lu", str, rec->counter); |
558 | ||
559 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
fa6f0cc7 | 560 | seq_puts(m, " "); |
34886c8b | 561 | |
e330b3bc CD |
562 | /* Sample standard deviation (s^2) */ |
563 | if (rec->counter <= 1) | |
564 | stddev = 0; | |
565 | else { | |
52d85d76 JL |
566 | /* |
567 | * Apply Welford's method: | |
568 | * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2) | |
569 | */ | |
570 | stddev = rec->counter * rec->time_squared - | |
571 | rec->time * rec->time; | |
572 | ||
e330b3bc CD |
573 | /* |
574 | * Divide only 1000 for ns^2 -> us^2 conversion. | |
575 | * trace_print_graph_duration will divide 1000 again. | |
576 | */ | |
e31f7939 WY |
577 | stddev = div64_ul(stddev, |
578 | rec->counter * (rec->counter - 1) * 1000); | |
e330b3bc CD |
579 | } |
580 | ||
34886c8b SR |
581 | trace_seq_init(&s); |
582 | trace_print_graph_duration(rec->time, &s); | |
583 | trace_seq_puts(&s, " "); | |
584 | trace_print_graph_duration(avg, &s); | |
e330b3bc CD |
585 | trace_seq_puts(&s, " "); |
586 | trace_print_graph_duration(stddev, &s); | |
0706f1c4 | 587 | trace_print_seq(m, &s); |
0706f1c4 SR |
588 | #endif |
589 | seq_putc(m, '\n'); | |
3aaba20f LZ |
590 | out: |
591 | mutex_unlock(&ftrace_profile_lock); | |
bac429f0 | 592 | |
3aaba20f | 593 | return ret; |
bac429f0 SR |
594 | } |
595 | ||
cafb168a | 596 | static void ftrace_profile_reset(struct ftrace_profile_stat *stat) |
bac429f0 | 597 | { |
493762fc | 598 | struct ftrace_profile_page *pg; |
bac429f0 | 599 | |
cafb168a | 600 | pg = stat->pages = stat->start; |
bac429f0 | 601 | |
493762fc SR |
602 | while (pg) { |
603 | memset(pg->records, 0, PROFILE_RECORDS_SIZE); | |
604 | pg->index = 0; | |
605 | pg = pg->next; | |
bac429f0 SR |
606 | } |
607 | ||
cafb168a | 608 | memset(stat->hash, 0, |
493762fc SR |
609 | FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head)); |
610 | } | |
bac429f0 | 611 | |
172f7ba9 | 612 | static int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) |
493762fc SR |
613 | { |
614 | struct ftrace_profile_page *pg; | |
318e0a73 SR |
615 | int functions; |
616 | int pages; | |
493762fc | 617 | int i; |
bac429f0 | 618 | |
493762fc | 619 | /* If we already allocated, do nothing */ |
cafb168a | 620 | if (stat->pages) |
493762fc | 621 | return 0; |
bac429f0 | 622 | |
cafb168a SR |
623 | stat->pages = (void *)get_zeroed_page(GFP_KERNEL); |
624 | if (!stat->pages) | |
493762fc | 625 | return -ENOMEM; |
bac429f0 | 626 | |
318e0a73 SR |
627 | #ifdef CONFIG_DYNAMIC_FTRACE |
628 | functions = ftrace_update_tot_cnt; | |
629 | #else | |
630 | /* | |
631 | * We do not know the number of functions that exist because | |
632 | * dynamic tracing is what counts them. With past experience | |
633 | * we have around 20K functions. That should be more than enough. | |
634 | * It is highly unlikely we will execute every function in | |
635 | * the kernel. | |
636 | */ | |
637 | functions = 20000; | |
638 | #endif | |
639 | ||
cafb168a | 640 | pg = stat->start = stat->pages; |
bac429f0 | 641 | |
318e0a73 SR |
642 | pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE); |
643 | ||
39e30cd1 | 644 | for (i = 1; i < pages; i++) { |
493762fc | 645 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); |
493762fc | 646 | if (!pg->next) |
318e0a73 | 647 | goto out_free; |
493762fc SR |
648 | pg = pg->next; |
649 | } | |
650 | ||
651 | return 0; | |
318e0a73 SR |
652 | |
653 | out_free: | |
654 | pg = stat->start; | |
655 | while (pg) { | |
656 | unsigned long tmp = (unsigned long)pg; | |
657 | ||
658 | pg = pg->next; | |
659 | free_page(tmp); | |
660 | } | |
661 | ||
318e0a73 SR |
662 | stat->pages = NULL; |
663 | stat->start = NULL; | |
664 | ||
665 | return -ENOMEM; | |
bac429f0 SR |
666 | } |
667 | ||
cafb168a | 668 | static int ftrace_profile_init_cpu(int cpu) |
bac429f0 | 669 | { |
cafb168a | 670 | struct ftrace_profile_stat *stat; |
493762fc | 671 | int size; |
bac429f0 | 672 | |
cafb168a SR |
673 | stat = &per_cpu(ftrace_profile_stats, cpu); |
674 | ||
675 | if (stat->hash) { | |
493762fc | 676 | /* If the profile is already created, simply reset it */ |
cafb168a | 677 | ftrace_profile_reset(stat); |
493762fc SR |
678 | return 0; |
679 | } | |
bac429f0 | 680 | |
493762fc SR |
681 | /* |
682 | * We are profiling all functions, but usually only a few thousand | |
683 | * functions are hit. We'll make a hash of 1024 items. | |
684 | */ | |
685 | size = FTRACE_PROFILE_HASH_SIZE; | |
bac429f0 | 686 | |
6396bb22 | 687 | stat->hash = kcalloc(size, sizeof(struct hlist_head), GFP_KERNEL); |
493762fc | 688 | |
cafb168a | 689 | if (!stat->hash) |
493762fc SR |
690 | return -ENOMEM; |
691 | ||
318e0a73 | 692 | /* Preallocate the function profiling pages */ |
cafb168a SR |
693 | if (ftrace_profile_pages_init(stat) < 0) { |
694 | kfree(stat->hash); | |
695 | stat->hash = NULL; | |
493762fc SR |
696 | return -ENOMEM; |
697 | } | |
698 | ||
699 | return 0; | |
bac429f0 SR |
700 | } |
701 | ||
cafb168a SR |
702 | static int ftrace_profile_init(void) |
703 | { | |
704 | int cpu; | |
705 | int ret = 0; | |
706 | ||
c4602c1c | 707 | for_each_possible_cpu(cpu) { |
cafb168a SR |
708 | ret = ftrace_profile_init_cpu(cpu); |
709 | if (ret) | |
710 | break; | |
711 | } | |
712 | ||
713 | return ret; | |
714 | } | |
715 | ||
493762fc | 716 | /* interrupts must be disabled */ |
cafb168a SR |
717 | static struct ftrace_profile * |
718 | ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip) | |
bac429f0 | 719 | { |
493762fc | 720 | struct ftrace_profile *rec; |
bac429f0 | 721 | struct hlist_head *hhd; |
bac429f0 SR |
722 | unsigned long key; |
723 | ||
20079ebe | 724 | key = hash_long(ip, FTRACE_PROFILE_HASH_BITS); |
cafb168a | 725 | hhd = &stat->hash[key]; |
bac429f0 SR |
726 | |
727 | if (hlist_empty(hhd)) | |
728 | return NULL; | |
729 | ||
1bb539ca | 730 | hlist_for_each_entry_rcu_notrace(rec, hhd, node) { |
bac429f0 | 731 | if (rec->ip == ip) |
493762fc SR |
732 | return rec; |
733 | } | |
734 | ||
735 | return NULL; | |
736 | } | |
737 | ||
cafb168a SR |
738 | static void ftrace_add_profile(struct ftrace_profile_stat *stat, |
739 | struct ftrace_profile *rec) | |
493762fc SR |
740 | { |
741 | unsigned long key; | |
742 | ||
20079ebe | 743 | key = hash_long(rec->ip, FTRACE_PROFILE_HASH_BITS); |
cafb168a | 744 | hlist_add_head_rcu(&rec->node, &stat->hash[key]); |
493762fc SR |
745 | } |
746 | ||
318e0a73 SR |
747 | /* |
748 | * The memory is already allocated, this simply finds a new record to use. | |
749 | */ | |
493762fc | 750 | static struct ftrace_profile * |
318e0a73 | 751 | ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip) |
493762fc SR |
752 | { |
753 | struct ftrace_profile *rec = NULL; | |
754 | ||
318e0a73 | 755 | /* prevent recursion (from NMIs) */ |
cafb168a | 756 | if (atomic_inc_return(&stat->disabled) != 1) |
493762fc SR |
757 | goto out; |
758 | ||
493762fc | 759 | /* |
318e0a73 SR |
760 | * Try to find the function again since an NMI |
761 | * could have added it | |
493762fc | 762 | */ |
cafb168a | 763 | rec = ftrace_find_profiled_func(stat, ip); |
493762fc | 764 | if (rec) |
cafb168a | 765 | goto out; |
493762fc | 766 | |
cafb168a SR |
767 | if (stat->pages->index == PROFILES_PER_PAGE) { |
768 | if (!stat->pages->next) | |
769 | goto out; | |
770 | stat->pages = stat->pages->next; | |
bac429f0 | 771 | } |
493762fc | 772 | |
cafb168a | 773 | rec = &stat->pages->records[stat->pages->index++]; |
493762fc | 774 | rec->ip = ip; |
cafb168a | 775 | ftrace_add_profile(stat, rec); |
493762fc | 776 | |
bac429f0 | 777 | out: |
cafb168a | 778 | atomic_dec(&stat->disabled); |
bac429f0 SR |
779 | |
780 | return rec; | |
781 | } | |
782 | ||
783 | static void | |
2f5f6ad9 | 784 | function_profile_call(unsigned long ip, unsigned long parent_ip, |
d19ad077 | 785 | struct ftrace_ops *ops, struct ftrace_regs *fregs) |
bac429f0 | 786 | { |
cafb168a | 787 | struct ftrace_profile_stat *stat; |
493762fc | 788 | struct ftrace_profile *rec; |
bac429f0 SR |
789 | unsigned long flags; |
790 | ||
791 | if (!ftrace_profile_enabled) | |
792 | return; | |
793 | ||
794 | local_irq_save(flags); | |
cafb168a | 795 | |
bdffd893 | 796 | stat = this_cpu_ptr(&ftrace_profile_stats); |
0f6ce3de | 797 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
798 | goto out; |
799 | ||
800 | rec = ftrace_find_profiled_func(stat, ip); | |
493762fc | 801 | if (!rec) { |
318e0a73 | 802 | rec = ftrace_profile_alloc(stat, ip); |
493762fc SR |
803 | if (!rec) |
804 | goto out; | |
805 | } | |
bac429f0 SR |
806 | |
807 | rec->counter++; | |
808 | out: | |
809 | local_irq_restore(flags); | |
810 | } | |
811 | ||
0706f1c4 | 812 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e73e679f SRV |
813 | static bool fgraph_graph_time = true; |
814 | ||
815 | void ftrace_graph_graph_time_control(bool enable) | |
816 | { | |
817 | fgraph_graph_time = enable; | |
818 | } | |
819 | ||
0706f1c4 SR |
820 | static int profile_graph_entry(struct ftrace_graph_ent *trace) |
821 | { | |
b0e21a61 | 822 | struct ftrace_ret_stack *ret_stack; |
8861dd30 | 823 | |
a1e2e31d | 824 | function_profile_call(trace->func, 0, NULL, NULL); |
8861dd30 | 825 | |
a8f0f9e4 SRV |
826 | /* If function graph is shutting down, ret_stack can be NULL */ |
827 | if (!current->ret_stack) | |
828 | return 0; | |
829 | ||
b0e21a61 SRV |
830 | ret_stack = ftrace_graph_get_ret_stack(current, 0); |
831 | if (ret_stack) | |
832 | ret_stack->subtime = 0; | |
8861dd30 | 833 | |
0706f1c4 SR |
834 | return 1; |
835 | } | |
836 | ||
837 | static void profile_graph_return(struct ftrace_graph_ret *trace) | |
838 | { | |
b0e21a61 | 839 | struct ftrace_ret_stack *ret_stack; |
cafb168a | 840 | struct ftrace_profile_stat *stat; |
a2a16d6a | 841 | unsigned long long calltime; |
0706f1c4 | 842 | struct ftrace_profile *rec; |
cafb168a | 843 | unsigned long flags; |
0706f1c4 SR |
844 | |
845 | local_irq_save(flags); | |
bdffd893 | 846 | stat = this_cpu_ptr(&ftrace_profile_stats); |
0f6ce3de | 847 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
848 | goto out; |
849 | ||
37e44bc5 SR |
850 | /* If the calltime was zero'd ignore it */ |
851 | if (!trace->calltime) | |
852 | goto out; | |
853 | ||
a2a16d6a SR |
854 | calltime = trace->rettime - trace->calltime; |
855 | ||
55577204 | 856 | if (!fgraph_graph_time) { |
a2a16d6a SR |
857 | |
858 | /* Append this call time to the parent time to subtract */ | |
b0e21a61 SRV |
859 | ret_stack = ftrace_graph_get_ret_stack(current, 1); |
860 | if (ret_stack) | |
861 | ret_stack->subtime += calltime; | |
a2a16d6a | 862 | |
b0e21a61 SRV |
863 | ret_stack = ftrace_graph_get_ret_stack(current, 0); |
864 | if (ret_stack && ret_stack->subtime < calltime) | |
865 | calltime -= ret_stack->subtime; | |
a2a16d6a SR |
866 | else |
867 | calltime = 0; | |
868 | } | |
869 | ||
cafb168a | 870 | rec = ftrace_find_profiled_func(stat, trace->func); |
e330b3bc | 871 | if (rec) { |
a2a16d6a | 872 | rec->time += calltime; |
e330b3bc CD |
873 | rec->time_squared += calltime * calltime; |
874 | } | |
a2a16d6a | 875 | |
cafb168a | 876 | out: |
0706f1c4 SR |
877 | local_irq_restore(flags); |
878 | } | |
879 | ||
688f7089 SRV |
880 | static struct fgraph_ops fprofiler_ops = { |
881 | .entryfunc = &profile_graph_entry, | |
882 | .retfunc = &profile_graph_return, | |
883 | }; | |
884 | ||
0706f1c4 SR |
885 | static int register_ftrace_profiler(void) |
886 | { | |
688f7089 | 887 | return register_ftrace_graph(&fprofiler_ops); |
0706f1c4 SR |
888 | } |
889 | ||
890 | static void unregister_ftrace_profiler(void) | |
891 | { | |
688f7089 | 892 | unregister_ftrace_graph(&fprofiler_ops); |
0706f1c4 SR |
893 | } |
894 | #else | |
bd38c0e6 | 895 | static struct ftrace_ops ftrace_profile_ops __read_mostly = { |
fb9fb015 | 896 | .func = function_profile_call, |
a25d036d | 897 | .flags = FTRACE_OPS_FL_INITIALIZED, |
33b7f99c | 898 | INIT_OPS_HASH(ftrace_profile_ops) |
bac429f0 SR |
899 | }; |
900 | ||
0706f1c4 SR |
901 | static int register_ftrace_profiler(void) |
902 | { | |
903 | return register_ftrace_function(&ftrace_profile_ops); | |
904 | } | |
905 | ||
906 | static void unregister_ftrace_profiler(void) | |
907 | { | |
908 | unregister_ftrace_function(&ftrace_profile_ops); | |
909 | } | |
910 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
911 | ||
bac429f0 SR |
912 | static ssize_t |
913 | ftrace_profile_write(struct file *filp, const char __user *ubuf, | |
914 | size_t cnt, loff_t *ppos) | |
915 | { | |
916 | unsigned long val; | |
bac429f0 SR |
917 | int ret; |
918 | ||
22fe9b54 PH |
919 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
920 | if (ret) | |
bac429f0 SR |
921 | return ret; |
922 | ||
923 | val = !!val; | |
924 | ||
925 | mutex_lock(&ftrace_profile_lock); | |
926 | if (ftrace_profile_enabled ^ val) { | |
927 | if (val) { | |
493762fc SR |
928 | ret = ftrace_profile_init(); |
929 | if (ret < 0) { | |
930 | cnt = ret; | |
931 | goto out; | |
932 | } | |
933 | ||
0706f1c4 SR |
934 | ret = register_ftrace_profiler(); |
935 | if (ret < 0) { | |
936 | cnt = ret; | |
937 | goto out; | |
938 | } | |
bac429f0 SR |
939 | ftrace_profile_enabled = 1; |
940 | } else { | |
941 | ftrace_profile_enabled = 0; | |
0f6ce3de SR |
942 | /* |
943 | * unregister_ftrace_profiler calls stop_machine | |
74401729 | 944 | * so this acts like an synchronize_rcu. |
0f6ce3de | 945 | */ |
0706f1c4 | 946 | unregister_ftrace_profiler(); |
bac429f0 SR |
947 | } |
948 | } | |
493762fc | 949 | out: |
bac429f0 SR |
950 | mutex_unlock(&ftrace_profile_lock); |
951 | ||
cf8517cf | 952 | *ppos += cnt; |
bac429f0 SR |
953 | |
954 | return cnt; | |
955 | } | |
956 | ||
493762fc SR |
957 | static ssize_t |
958 | ftrace_profile_read(struct file *filp, char __user *ubuf, | |
959 | size_t cnt, loff_t *ppos) | |
960 | { | |
fb9fb015 | 961 | char buf[64]; /* big enough to hold a number */ |
493762fc SR |
962 | int r; |
963 | ||
964 | r = sprintf(buf, "%u\n", ftrace_profile_enabled); | |
965 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
966 | } | |
967 | ||
bac429f0 SR |
968 | static const struct file_operations ftrace_profile_fops = { |
969 | .open = tracing_open_generic, | |
970 | .read = ftrace_profile_read, | |
971 | .write = ftrace_profile_write, | |
6038f373 | 972 | .llseek = default_llseek, |
bac429f0 SR |
973 | }; |
974 | ||
cafb168a SR |
975 | /* used to initialize the real stat files */ |
976 | static struct tracer_stat function_stats __initdata = { | |
fb9fb015 SR |
977 | .name = "functions", |
978 | .stat_start = function_stat_start, | |
979 | .stat_next = function_stat_next, | |
980 | .stat_cmp = function_stat_cmp, | |
981 | .stat_headers = function_stat_headers, | |
982 | .stat_show = function_stat_show | |
cafb168a SR |
983 | }; |
984 | ||
8434dc93 | 985 | static __init void ftrace_profile_tracefs(struct dentry *d_tracer) |
bac429f0 | 986 | { |
cafb168a | 987 | struct ftrace_profile_stat *stat; |
cafb168a | 988 | char *name; |
bac429f0 | 989 | int ret; |
cafb168a SR |
990 | int cpu; |
991 | ||
992 | for_each_possible_cpu(cpu) { | |
993 | stat = &per_cpu(ftrace_profile_stats, cpu); | |
994 | ||
6363c6b5 | 995 | name = kasprintf(GFP_KERNEL, "function%d", cpu); |
cafb168a SR |
996 | if (!name) { |
997 | /* | |
998 | * The files created are permanent, if something happens | |
999 | * we still do not free memory. | |
1000 | */ | |
cafb168a SR |
1001 | WARN(1, |
1002 | "Could not allocate stat file for cpu %d\n", | |
1003 | cpu); | |
1004 | return; | |
1005 | } | |
1006 | stat->stat = function_stats; | |
cafb168a SR |
1007 | stat->stat.name = name; |
1008 | ret = register_stat_tracer(&stat->stat); | |
1009 | if (ret) { | |
1010 | WARN(1, | |
1011 | "Could not register function stat for cpu %d\n", | |
1012 | cpu); | |
1013 | kfree(name); | |
1014 | return; | |
1015 | } | |
bac429f0 SR |
1016 | } |
1017 | ||
e4931b82 YW |
1018 | trace_create_file("function_profile_enabled", |
1019 | TRACE_MODE_WRITE, d_tracer, NULL, | |
1020 | &ftrace_profile_fops); | |
bac429f0 SR |
1021 | } |
1022 | ||
bac429f0 | 1023 | #else /* CONFIG_FUNCTION_PROFILER */ |
8434dc93 | 1024 | static __init void ftrace_profile_tracefs(struct dentry *d_tracer) |
bac429f0 SR |
1025 | { |
1026 | } | |
bac429f0 SR |
1027 | #endif /* CONFIG_FUNCTION_PROFILER */ |
1028 | ||
493762fc SR |
1029 | #ifdef CONFIG_DYNAMIC_FTRACE |
1030 | ||
79922b80 SRRH |
1031 | static struct ftrace_ops *removed_ops; |
1032 | ||
e1effa01 SRRH |
1033 | /* |
1034 | * Set when doing a global update, like enabling all recs or disabling them. | |
1035 | * It is not set when just updating a single ftrace_ops. | |
1036 | */ | |
1037 | static bool update_all_ops; | |
1038 | ||
493762fc SR |
1039 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD |
1040 | # error Dynamic ftrace depends on MCOUNT_RECORD | |
1041 | #endif | |
1042 | ||
7b60f3d8 SRV |
1043 | struct ftrace_func_probe { |
1044 | struct ftrace_probe_ops *probe_ops; | |
1045 | struct ftrace_ops ops; | |
1046 | struct trace_array *tr; | |
1047 | struct list_head list; | |
6e444319 | 1048 | void *data; |
7b60f3d8 SRV |
1049 | int ref; |
1050 | }; | |
1051 | ||
33dc9b12 SR |
1052 | /* |
1053 | * We make these constant because no one should touch them, | |
1054 | * but they are used as the default "empty hash", to avoid allocating | |
1055 | * it all the time. These are in a read only section such that if | |
1056 | * anyone does try to modify it, it will cause an exception. | |
1057 | */ | |
1058 | static const struct hlist_head empty_buckets[1]; | |
1059 | static const struct ftrace_hash empty_hash = { | |
1060 | .buckets = (struct hlist_head *)empty_buckets, | |
1cf41dd7 | 1061 | }; |
33dc9b12 | 1062 | #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash) |
493762fc | 1063 | |
3306fc4a | 1064 | struct ftrace_ops global_ops = { |
33b7f99c SRRH |
1065 | .func = ftrace_stub, |
1066 | .local_hash.notrace_hash = EMPTY_HASH, | |
1067 | .local_hash.filter_hash = EMPTY_HASH, | |
1068 | INIT_OPS_HASH(global_ops) | |
a25d036d | 1069 | .flags = FTRACE_OPS_FL_INITIALIZED | |
e3eea140 | 1070 | FTRACE_OPS_FL_PID, |
f45948e8 SR |
1071 | }; |
1072 | ||
aec0be2d | 1073 | /* |
f2cc020d | 1074 | * Used by the stack unwinder to know about dynamic ftrace trampolines. |
aec0be2d | 1075 | */ |
6be7fa3c | 1076 | struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr) |
aec0be2d | 1077 | { |
6be7fa3c | 1078 | struct ftrace_ops *op = NULL; |
aec0be2d SRRH |
1079 | |
1080 | /* | |
1081 | * Some of the ops may be dynamically allocated, | |
74401729 | 1082 | * they are freed after a synchronize_rcu(). |
aec0be2d SRRH |
1083 | */ |
1084 | preempt_disable_notrace(); | |
1085 | ||
1086 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
1087 | /* | |
1088 | * This is to check for dynamically allocated trampolines. | |
1089 | * Trampolines that are in kernel text will have | |
1090 | * core_kernel_text() return true. | |
1091 | */ | |
1092 | if (op->trampoline && op->trampoline_size) | |
1093 | if (addr >= op->trampoline && | |
1094 | addr < op->trampoline + op->trampoline_size) { | |
6be7fa3c SRV |
1095 | preempt_enable_notrace(); |
1096 | return op; | |
aec0be2d SRRH |
1097 | } |
1098 | } while_for_each_ftrace_op(op); | |
aec0be2d SRRH |
1099 | preempt_enable_notrace(); |
1100 | ||
6be7fa3c SRV |
1101 | return NULL; |
1102 | } | |
1103 | ||
1104 | /* | |
1105 | * This is used by __kernel_text_address() to return true if the | |
1106 | * address is on a dynamically allocated trampoline that would | |
1107 | * not return true for either core_kernel_text() or | |
1108 | * is_module_text_address(). | |
1109 | */ | |
1110 | bool is_ftrace_trampoline(unsigned long addr) | |
1111 | { | |
1112 | return ftrace_ops_trampoline(addr) != NULL; | |
aec0be2d SRRH |
1113 | } |
1114 | ||
493762fc SR |
1115 | struct ftrace_page { |
1116 | struct ftrace_page *next; | |
a7900875 | 1117 | struct dyn_ftrace *records; |
493762fc | 1118 | int index; |
db42523b | 1119 | int order; |
493762fc SR |
1120 | }; |
1121 | ||
a7900875 SR |
1122 | #define ENTRY_SIZE sizeof(struct dyn_ftrace) |
1123 | #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE) | |
493762fc | 1124 | |
493762fc SR |
1125 | static struct ftrace_page *ftrace_pages_start; |
1126 | static struct ftrace_page *ftrace_pages; | |
1127 | ||
2b0cce0e SRV |
1128 | static __always_inline unsigned long |
1129 | ftrace_hash_key(struct ftrace_hash *hash, unsigned long ip) | |
1130 | { | |
1131 | if (hash->size_bits > 0) | |
1132 | return hash_long(ip, hash->size_bits); | |
1133 | ||
1134 | return 0; | |
1135 | } | |
1136 | ||
2b2c279c SRV |
1137 | /* Only use this function if ftrace_hash_empty() has already been tested */ |
1138 | static __always_inline struct ftrace_func_entry * | |
1139 | __ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) | |
b448c4e3 SR |
1140 | { |
1141 | unsigned long key; | |
1142 | struct ftrace_func_entry *entry; | |
1143 | struct hlist_head *hhd; | |
b448c4e3 | 1144 | |
2b0cce0e | 1145 | key = ftrace_hash_key(hash, ip); |
b448c4e3 SR |
1146 | hhd = &hash->buckets[key]; |
1147 | ||
1bb539ca | 1148 | hlist_for_each_entry_rcu_notrace(entry, hhd, hlist) { |
b448c4e3 SR |
1149 | if (entry->ip == ip) |
1150 | return entry; | |
1151 | } | |
1152 | return NULL; | |
1153 | } | |
1154 | ||
2b2c279c SRV |
1155 | /** |
1156 | * ftrace_lookup_ip - Test to see if an ip exists in an ftrace_hash | |
1157 | * @hash: The hash to look at | |
1158 | * @ip: The instruction pointer to test | |
1159 | * | |
1160 | * Search a given @hash to see if a given instruction pointer (@ip) | |
1161 | * exists in it. | |
1162 | * | |
d1530413 | 1163 | * Returns: the entry that holds the @ip if found. NULL otherwise. |
2b2c279c SRV |
1164 | */ |
1165 | struct ftrace_func_entry * | |
1166 | ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) | |
1167 | { | |
1168 | if (ftrace_hash_empty(hash)) | |
1169 | return NULL; | |
1170 | ||
1171 | return __ftrace_lookup_ip(hash, ip); | |
1172 | } | |
1173 | ||
33dc9b12 SR |
1174 | static void __add_hash_entry(struct ftrace_hash *hash, |
1175 | struct ftrace_func_entry *entry) | |
b448c4e3 | 1176 | { |
b448c4e3 SR |
1177 | struct hlist_head *hhd; |
1178 | unsigned long key; | |
1179 | ||
2b0cce0e | 1180 | key = ftrace_hash_key(hash, entry->ip); |
b448c4e3 SR |
1181 | hhd = &hash->buckets[key]; |
1182 | hlist_add_head(&entry->hlist, hhd); | |
1183 | hash->count++; | |
33dc9b12 SR |
1184 | } |
1185 | ||
d05cb470 SRG |
1186 | static struct ftrace_func_entry * |
1187 | add_hash_entry(struct ftrace_hash *hash, unsigned long ip) | |
33dc9b12 SR |
1188 | { |
1189 | struct ftrace_func_entry *entry; | |
1190 | ||
1191 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
1192 | if (!entry) | |
d05cb470 | 1193 | return NULL; |
33dc9b12 SR |
1194 | |
1195 | entry->ip = ip; | |
1196 | __add_hash_entry(hash, entry); | |
b448c4e3 | 1197 | |
d05cb470 | 1198 | return entry; |
b448c4e3 SR |
1199 | } |
1200 | ||
1201 | static void | |
33dc9b12 | 1202 | free_hash_entry(struct ftrace_hash *hash, |
b448c4e3 SR |
1203 | struct ftrace_func_entry *entry) |
1204 | { | |
1205 | hlist_del(&entry->hlist); | |
1206 | kfree(entry); | |
1207 | hash->count--; | |
1208 | } | |
1209 | ||
33dc9b12 SR |
1210 | static void |
1211 | remove_hash_entry(struct ftrace_hash *hash, | |
1212 | struct ftrace_func_entry *entry) | |
1213 | { | |
eee8ded1 | 1214 | hlist_del_rcu(&entry->hlist); |
33dc9b12 SR |
1215 | hash->count--; |
1216 | } | |
1217 | ||
b448c4e3 SR |
1218 | static void ftrace_hash_clear(struct ftrace_hash *hash) |
1219 | { | |
1220 | struct hlist_head *hhd; | |
b67bfe0d | 1221 | struct hlist_node *tn; |
b448c4e3 SR |
1222 | struct ftrace_func_entry *entry; |
1223 | int size = 1 << hash->size_bits; | |
1224 | int i; | |
1225 | ||
33dc9b12 SR |
1226 | if (!hash->count) |
1227 | return; | |
1228 | ||
b448c4e3 SR |
1229 | for (i = 0; i < size; i++) { |
1230 | hhd = &hash->buckets[i]; | |
b67bfe0d | 1231 | hlist_for_each_entry_safe(entry, tn, hhd, hlist) |
33dc9b12 | 1232 | free_hash_entry(hash, entry); |
b448c4e3 SR |
1233 | } |
1234 | FTRACE_WARN_ON(hash->count); | |
1235 | } | |
1236 | ||
673feb9d SRV |
1237 | static void free_ftrace_mod(struct ftrace_mod_load *ftrace_mod) |
1238 | { | |
1239 | list_del(&ftrace_mod->list); | |
1240 | kfree(ftrace_mod->module); | |
1241 | kfree(ftrace_mod->func); | |
1242 | kfree(ftrace_mod); | |
1243 | } | |
1244 | ||
1245 | static void clear_ftrace_mod_list(struct list_head *head) | |
1246 | { | |
1247 | struct ftrace_mod_load *p, *n; | |
1248 | ||
1249 | /* stack tracer isn't supported yet */ | |
1250 | if (!head) | |
1251 | return; | |
1252 | ||
1253 | mutex_lock(&ftrace_lock); | |
1254 | list_for_each_entry_safe(p, n, head, list) | |
1255 | free_ftrace_mod(p); | |
1256 | mutex_unlock(&ftrace_lock); | |
1257 | } | |
1258 | ||
33dc9b12 SR |
1259 | static void free_ftrace_hash(struct ftrace_hash *hash) |
1260 | { | |
1261 | if (!hash || hash == EMPTY_HASH) | |
1262 | return; | |
1263 | ftrace_hash_clear(hash); | |
1264 | kfree(hash->buckets); | |
1265 | kfree(hash); | |
1266 | } | |
1267 | ||
07fd5515 SR |
1268 | static void __free_ftrace_hash_rcu(struct rcu_head *rcu) |
1269 | { | |
1270 | struct ftrace_hash *hash; | |
1271 | ||
1272 | hash = container_of(rcu, struct ftrace_hash, rcu); | |
1273 | free_ftrace_hash(hash); | |
1274 | } | |
1275 | ||
1276 | static void free_ftrace_hash_rcu(struct ftrace_hash *hash) | |
1277 | { | |
1278 | if (!hash || hash == EMPTY_HASH) | |
1279 | return; | |
74401729 | 1280 | call_rcu(&hash->rcu, __free_ftrace_hash_rcu); |
07fd5515 SR |
1281 | } |
1282 | ||
8be9fbd5 MR |
1283 | /** |
1284 | * ftrace_free_filter - remove all filters for an ftrace_ops | |
d1530413 | 1285 | * @ops: the ops to remove the filters from |
8be9fbd5 | 1286 | */ |
5500fa51 JO |
1287 | void ftrace_free_filter(struct ftrace_ops *ops) |
1288 | { | |
f04f24fb | 1289 | ftrace_ops_init(ops); |
33b7f99c SRRH |
1290 | free_ftrace_hash(ops->func_hash->filter_hash); |
1291 | free_ftrace_hash(ops->func_hash->notrace_hash); | |
5500fa51 | 1292 | } |
8be9fbd5 | 1293 | EXPORT_SYMBOL_GPL(ftrace_free_filter); |
5500fa51 | 1294 | |
33dc9b12 SR |
1295 | static struct ftrace_hash *alloc_ftrace_hash(int size_bits) |
1296 | { | |
1297 | struct ftrace_hash *hash; | |
1298 | int size; | |
1299 | ||
1300 | hash = kzalloc(sizeof(*hash), GFP_KERNEL); | |
1301 | if (!hash) | |
1302 | return NULL; | |
1303 | ||
1304 | size = 1 << size_bits; | |
47b0edcb | 1305 | hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL); |
33dc9b12 SR |
1306 | |
1307 | if (!hash->buckets) { | |
1308 | kfree(hash); | |
1309 | return NULL; | |
1310 | } | |
1311 | ||
1312 | hash->size_bits = size_bits; | |
1313 | ||
1314 | return hash; | |
1315 | } | |
1316 | ||
673feb9d SRV |
1317 | |
1318 | static int ftrace_add_mod(struct trace_array *tr, | |
1319 | const char *func, const char *module, | |
1320 | int enable) | |
1321 | { | |
1322 | struct ftrace_mod_load *ftrace_mod; | |
1323 | struct list_head *mod_head = enable ? &tr->mod_trace : &tr->mod_notrace; | |
1324 | ||
1325 | ftrace_mod = kzalloc(sizeof(*ftrace_mod), GFP_KERNEL); | |
1326 | if (!ftrace_mod) | |
1327 | return -ENOMEM; | |
1328 | ||
19ba6c8a | 1329 | INIT_LIST_HEAD(&ftrace_mod->list); |
673feb9d SRV |
1330 | ftrace_mod->func = kstrdup(func, GFP_KERNEL); |
1331 | ftrace_mod->module = kstrdup(module, GFP_KERNEL); | |
1332 | ftrace_mod->enable = enable; | |
1333 | ||
1334 | if (!ftrace_mod->func || !ftrace_mod->module) | |
1335 | goto out_free; | |
1336 | ||
1337 | list_add(&ftrace_mod->list, mod_head); | |
1338 | ||
1339 | return 0; | |
1340 | ||
1341 | out_free: | |
1342 | free_ftrace_mod(ftrace_mod); | |
1343 | ||
1344 | return -ENOMEM; | |
1345 | } | |
1346 | ||
33dc9b12 SR |
1347 | static struct ftrace_hash * |
1348 | alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash) | |
1349 | { | |
1350 | struct ftrace_func_entry *entry; | |
1351 | struct ftrace_hash *new_hash; | |
33dc9b12 | 1352 | int size; |
33dc9b12 SR |
1353 | int i; |
1354 | ||
1355 | new_hash = alloc_ftrace_hash(size_bits); | |
1356 | if (!new_hash) | |
1357 | return NULL; | |
1358 | ||
8c08f0d5 SRV |
1359 | if (hash) |
1360 | new_hash->flags = hash->flags; | |
1361 | ||
33dc9b12 | 1362 | /* Empty hash? */ |
06a51d93 | 1363 | if (ftrace_hash_empty(hash)) |
33dc9b12 SR |
1364 | return new_hash; |
1365 | ||
1366 | size = 1 << hash->size_bits; | |
1367 | for (i = 0; i < size; i++) { | |
b67bfe0d | 1368 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { |
d05cb470 | 1369 | if (add_hash_entry(new_hash, entry->ip) == NULL) |
33dc9b12 SR |
1370 | goto free_hash; |
1371 | } | |
1372 | } | |
1373 | ||
1374 | FTRACE_WARN_ON(new_hash->count != hash->count); | |
1375 | ||
1376 | return new_hash; | |
1377 | ||
1378 | free_hash: | |
1379 | free_ftrace_hash(new_hash); | |
1380 | return NULL; | |
1381 | } | |
1382 | ||
41fb61c2 | 1383 | static void |
84261912 | 1384 | ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, int filter_hash); |
41fb61c2 | 1385 | static void |
84261912 | 1386 | ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, int filter_hash); |
41fb61c2 | 1387 | |
f8b8be8a MH |
1388 | static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops, |
1389 | struct ftrace_hash *new_hash); | |
1390 | ||
714641c3 | 1391 | static struct ftrace_hash *dup_hash(struct ftrace_hash *src, int size) |
33dc9b12 SR |
1392 | { |
1393 | struct ftrace_func_entry *entry; | |
07fd5515 | 1394 | struct ftrace_hash *new_hash; |
714641c3 SRV |
1395 | struct hlist_head *hhd; |
1396 | struct hlist_node *tn; | |
33dc9b12 SR |
1397 | int bits = 0; |
1398 | int i; | |
1399 | ||
33dc9b12 | 1400 | /* |
be493132 SRV |
1401 | * Use around half the size (max bit of it), but |
1402 | * a minimum of 2 is fine (as size of 0 or 1 both give 1 for bits). | |
33dc9b12 | 1403 | */ |
be493132 | 1404 | bits = fls(size / 2); |
33dc9b12 SR |
1405 | |
1406 | /* Don't allocate too much */ | |
1407 | if (bits > FTRACE_HASH_MAX_BITS) | |
1408 | bits = FTRACE_HASH_MAX_BITS; | |
1409 | ||
07fd5515 SR |
1410 | new_hash = alloc_ftrace_hash(bits); |
1411 | if (!new_hash) | |
3e278c0d | 1412 | return NULL; |
33dc9b12 | 1413 | |
8c08f0d5 SRV |
1414 | new_hash->flags = src->flags; |
1415 | ||
33dc9b12 SR |
1416 | size = 1 << src->size_bits; |
1417 | for (i = 0; i < size; i++) { | |
1418 | hhd = &src->buckets[i]; | |
b67bfe0d | 1419 | hlist_for_each_entry_safe(entry, tn, hhd, hlist) { |
33dc9b12 | 1420 | remove_hash_entry(src, entry); |
07fd5515 | 1421 | __add_hash_entry(new_hash, entry); |
33dc9b12 SR |
1422 | } |
1423 | } | |
3e278c0d NK |
1424 | return new_hash; |
1425 | } | |
1426 | ||
714641c3 SRV |
1427 | static struct ftrace_hash * |
1428 | __ftrace_hash_move(struct ftrace_hash *src) | |
1429 | { | |
1430 | int size = src->count; | |
1431 | ||
1432 | /* | |
1433 | * If the new source is empty, just return the empty_hash. | |
1434 | */ | |
1435 | if (ftrace_hash_empty(src)) | |
1436 | return EMPTY_HASH; | |
1437 | ||
1438 | return dup_hash(src, size); | |
1439 | } | |
1440 | ||
3e278c0d NK |
1441 | static int |
1442 | ftrace_hash_move(struct ftrace_ops *ops, int enable, | |
1443 | struct ftrace_hash **dst, struct ftrace_hash *src) | |
1444 | { | |
1445 | struct ftrace_hash *new_hash; | |
1446 | int ret; | |
1447 | ||
1448 | /* Reject setting notrace hash on IPMODIFY ftrace_ops */ | |
1449 | if (ops->flags & FTRACE_OPS_FL_IPMODIFY && !enable) | |
1450 | return -EINVAL; | |
1451 | ||
1452 | new_hash = __ftrace_hash_move(src); | |
1453 | if (!new_hash) | |
1454 | return -ENOMEM; | |
1455 | ||
f8b8be8a MH |
1456 | /* Make sure this can be applied if it is IPMODIFY ftrace_ops */ |
1457 | if (enable) { | |
1458 | /* IPMODIFY should be updated only when filter_hash updating */ | |
1459 | ret = ftrace_hash_ipmodify_update(ops, new_hash); | |
1460 | if (ret < 0) { | |
1461 | free_ftrace_hash(new_hash); | |
1462 | return ret; | |
1463 | } | |
1464 | } | |
1465 | ||
5c27c775 MH |
1466 | /* |
1467 | * Remove the current set, update the hash and add | |
1468 | * them back. | |
1469 | */ | |
84261912 | 1470 | ftrace_hash_rec_disable_modify(ops, enable); |
5c27c775 | 1471 | |
07fd5515 | 1472 | rcu_assign_pointer(*dst, new_hash); |
07fd5515 | 1473 | |
84261912 | 1474 | ftrace_hash_rec_enable_modify(ops, enable); |
41fb61c2 | 1475 | |
5c27c775 | 1476 | return 0; |
33dc9b12 SR |
1477 | } |
1478 | ||
fef5aeee SRRH |
1479 | static bool hash_contains_ip(unsigned long ip, |
1480 | struct ftrace_ops_hash *hash) | |
1481 | { | |
1482 | /* | |
1483 | * The function record is a match if it exists in the filter | |
fdda88d3 | 1484 | * hash and not in the notrace hash. Note, an empty hash is |
fef5aeee SRRH |
1485 | * considered a match for the filter hash, but an empty |
1486 | * notrace hash is considered not in the notrace hash. | |
1487 | */ | |
1488 | return (ftrace_hash_empty(hash->filter_hash) || | |
2b2c279c | 1489 | __ftrace_lookup_ip(hash->filter_hash, ip)) && |
fef5aeee | 1490 | (ftrace_hash_empty(hash->notrace_hash) || |
2b2c279c | 1491 | !__ftrace_lookup_ip(hash->notrace_hash, ip)); |
fef5aeee SRRH |
1492 | } |
1493 | ||
b848914c SR |
1494 | /* |
1495 | * Test the hashes for this ops to see if we want to call | |
1496 | * the ops->func or not. | |
1497 | * | |
1498 | * It's a match if the ip is in the ops->filter_hash or | |
1499 | * the filter_hash does not exist or is empty, | |
1500 | * AND | |
1501 | * the ip is not in the ops->notrace_hash. | |
cdbe61bf SR |
1502 | * |
1503 | * This needs to be called with preemption disabled as | |
74401729 | 1504 | * the hashes are freed with call_rcu(). |
b848914c | 1505 | */ |
3306fc4a | 1506 | int |
195a8afc | 1507 | ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs) |
b848914c | 1508 | { |
fef5aeee | 1509 | struct ftrace_ops_hash hash; |
b848914c SR |
1510 | int ret; |
1511 | ||
195a8afc SRRH |
1512 | #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS |
1513 | /* | |
1514 | * There's a small race when adding ops that the ftrace handler | |
1515 | * that wants regs, may be called without them. We can not | |
1516 | * allow that handler to be called if regs is NULL. | |
1517 | */ | |
1518 | if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS)) | |
1519 | return 0; | |
1520 | #endif | |
1521 | ||
f86f4180 CZ |
1522 | rcu_assign_pointer(hash.filter_hash, ops->func_hash->filter_hash); |
1523 | rcu_assign_pointer(hash.notrace_hash, ops->func_hash->notrace_hash); | |
b848914c | 1524 | |
fef5aeee | 1525 | if (hash_contains_ip(ip, &hash)) |
b848914c SR |
1526 | ret = 1; |
1527 | else | |
1528 | ret = 0; | |
b848914c SR |
1529 | |
1530 | return ret; | |
1531 | } | |
1532 | ||
493762fc SR |
1533 | /* |
1534 | * This is a double for. Do not use 'break' to break out of the loop, | |
1535 | * you must use a goto. | |
1536 | */ | |
1537 | #define do_for_each_ftrace_rec(pg, rec) \ | |
1538 | for (pg = ftrace_pages_start; pg; pg = pg->next) { \ | |
1539 | int _____i; \ | |
1540 | for (_____i = 0; _____i < pg->index; _____i++) { \ | |
1541 | rec = &pg->records[_____i]; | |
1542 | ||
1543 | #define while_for_each_ftrace_rec() \ | |
1544 | } \ | |
1545 | } | |
1546 | ||
5855fead SR |
1547 | |
1548 | static int ftrace_cmp_recs(const void *a, const void *b) | |
1549 | { | |
a650e02a SR |
1550 | const struct dyn_ftrace *key = a; |
1551 | const struct dyn_ftrace *rec = b; | |
5855fead | 1552 | |
a650e02a | 1553 | if (key->flags < rec->ip) |
5855fead | 1554 | return -1; |
a650e02a SR |
1555 | if (key->ip >= rec->ip + MCOUNT_INSN_SIZE) |
1556 | return 1; | |
5855fead SR |
1557 | return 0; |
1558 | } | |
1559 | ||
7e16f581 SRV |
1560 | static struct dyn_ftrace *lookup_rec(unsigned long start, unsigned long end) |
1561 | { | |
1562 | struct ftrace_page *pg; | |
1563 | struct dyn_ftrace *rec = NULL; | |
1564 | struct dyn_ftrace key; | |
1565 | ||
1566 | key.ip = start; | |
1567 | key.flags = end; /* overload flags, as it is unsigned long */ | |
1568 | ||
1569 | for (pg = ftrace_pages_start; pg; pg = pg->next) { | |
ee92fa44 CZ |
1570 | if (pg->index == 0 || |
1571 | end < pg->records[0].ip || | |
7e16f581 SRV |
1572 | start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE)) |
1573 | continue; | |
1574 | rec = bsearch(&key, pg->records, pg->index, | |
1575 | sizeof(struct dyn_ftrace), | |
1576 | ftrace_cmp_recs); | |
d9815bff AS |
1577 | if (rec) |
1578 | break; | |
7e16f581 SRV |
1579 | } |
1580 | return rec; | |
1581 | } | |
1582 | ||
04cf31a7 ME |
1583 | /** |
1584 | * ftrace_location_range - return the first address of a traced location | |
1585 | * if it touches the given ip range | |
1586 | * @start: start of range to search. | |
1587 | * @end: end of range to search (inclusive). @end points to the last byte | |
1588 | * to check. | |
1589 | * | |
d1530413 | 1590 | * Returns: rec->ip if the related ftrace location is a least partly within |
04cf31a7 ME |
1591 | * the given address range. That is, the first address of the instruction |
1592 | * that is either a NOP or call to the function tracer. It checks the ftrace | |
1593 | * internal tables to determine if the address belongs or not. | |
1594 | */ | |
1595 | unsigned long ftrace_location_range(unsigned long start, unsigned long end) | |
c88fd863 | 1596 | { |
c88fd863 | 1597 | struct dyn_ftrace *rec; |
5855fead | 1598 | |
7e16f581 SRV |
1599 | rec = lookup_rec(start, end); |
1600 | if (rec) | |
1601 | return rec->ip; | |
c88fd863 SR |
1602 | |
1603 | return 0; | |
1604 | } | |
1605 | ||
a650e02a | 1606 | /** |
aebfd125 | 1607 | * ftrace_location - return the ftrace location |
a650e02a SR |
1608 | * @ip: the instruction pointer to check |
1609 | * | |
d1530413 RD |
1610 | * Returns: |
1611 | * * If @ip matches the ftrace location, return @ip. | |
1612 | * * If @ip matches sym+0, return sym's ftrace location. | |
1613 | * * Otherwise, return 0. | |
a650e02a | 1614 | */ |
f0cf973a | 1615 | unsigned long ftrace_location(unsigned long ip) |
a650e02a | 1616 | { |
aebfd125 PZ |
1617 | struct dyn_ftrace *rec; |
1618 | unsigned long offset; | |
1619 | unsigned long size; | |
1620 | ||
1621 | rec = lookup_rec(ip, ip); | |
1622 | if (!rec) { | |
1623 | if (!kallsyms_lookup_size_offset(ip, &size, &offset)) | |
1624 | goto out; | |
1625 | ||
1626 | /* map sym+0 to __fentry__ */ | |
1627 | if (!offset) | |
1628 | rec = lookup_rec(ip, ip + size - 1); | |
1629 | } | |
1630 | ||
1631 | if (rec) | |
1632 | return rec->ip; | |
1633 | ||
1634 | out: | |
1635 | return 0; | |
a650e02a SR |
1636 | } |
1637 | ||
1638 | /** | |
1639 | * ftrace_text_reserved - return true if range contains an ftrace location | |
1640 | * @start: start of range to search | |
1641 | * @end: end of range to search (inclusive). @end points to the last byte to check. | |
1642 | * | |
d1530413 | 1643 | * Returns: 1 if @start and @end contains a ftrace location. |
a650e02a SR |
1644 | * That is, the instruction that is either a NOP or call to |
1645 | * the function tracer. It checks the ftrace internal tables to | |
1646 | * determine if the address belongs or not. | |
1647 | */ | |
d88471cb | 1648 | int ftrace_text_reserved(const void *start, const void *end) |
a650e02a | 1649 | { |
f0cf973a SR |
1650 | unsigned long ret; |
1651 | ||
1652 | ret = ftrace_location_range((unsigned long)start, | |
1653 | (unsigned long)end); | |
1654 | ||
1655 | return (int)!!ret; | |
a650e02a SR |
1656 | } |
1657 | ||
4fbb48cb SRRH |
1658 | /* Test if ops registered to this rec needs regs */ |
1659 | static bool test_rec_ops_needs_regs(struct dyn_ftrace *rec) | |
1660 | { | |
1661 | struct ftrace_ops *ops; | |
1662 | bool keep_regs = false; | |
1663 | ||
1664 | for (ops = ftrace_ops_list; | |
1665 | ops != &ftrace_list_end; ops = ops->next) { | |
1666 | /* pass rec in as regs to have non-NULL val */ | |
1667 | if (ftrace_ops_test(ops, rec->ip, rec)) { | |
1668 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) { | |
1669 | keep_regs = true; | |
1670 | break; | |
1671 | } | |
1672 | } | |
1673 | } | |
1674 | ||
1675 | return keep_regs; | |
1676 | } | |
1677 | ||
a124692b CJ |
1678 | static struct ftrace_ops * |
1679 | ftrace_find_tramp_ops_any(struct dyn_ftrace *rec); | |
1680 | static struct ftrace_ops * | |
4c75b0ff NR |
1681 | ftrace_find_tramp_ops_any_other(struct dyn_ftrace *rec, struct ftrace_ops *op_exclude); |
1682 | static struct ftrace_ops * | |
a124692b CJ |
1683 | ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, struct ftrace_ops *ops); |
1684 | ||
cf04f2d5 SRG |
1685 | static bool skip_record(struct dyn_ftrace *rec) |
1686 | { | |
1687 | /* | |
1688 | * At boot up, weak functions are set to disable. Function tracing | |
1689 | * can be enabled before they are, and they still need to be disabled now. | |
1690 | * If the record is disabled, still continue if it is marked as already | |
1691 | * enabled (this is needed to keep the accounting working). | |
1692 | */ | |
1693 | return rec->flags & FTRACE_FL_DISABLED && | |
1694 | !(rec->flags & FTRACE_FL_ENABLED); | |
1695 | } | |
1696 | ||
84b6d3e6 | 1697 | static bool __ftrace_hash_rec_update(struct ftrace_ops *ops, |
ed926f9b SR |
1698 | int filter_hash, |
1699 | bool inc) | |
1700 | { | |
1701 | struct ftrace_hash *hash; | |
1702 | struct ftrace_hash *other_hash; | |
1703 | struct ftrace_page *pg; | |
1704 | struct dyn_ftrace *rec; | |
84b6d3e6 | 1705 | bool update = false; |
ed926f9b | 1706 | int count = 0; |
8c08f0d5 | 1707 | int all = false; |
ed926f9b SR |
1708 | |
1709 | /* Only update if the ops has been registered */ | |
1710 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
84b6d3e6 | 1711 | return false; |
ed926f9b SR |
1712 | |
1713 | /* | |
1714 | * In the filter_hash case: | |
1715 | * If the count is zero, we update all records. | |
1716 | * Otherwise we just update the items in the hash. | |
1717 | * | |
1718 | * In the notrace_hash case: | |
1719 | * We enable the update in the hash. | |
1720 | * As disabling notrace means enabling the tracing, | |
1721 | * and enabling notrace means disabling, the inc variable | |
1722 | * gets inversed. | |
1723 | */ | |
1724 | if (filter_hash) { | |
33b7f99c SRRH |
1725 | hash = ops->func_hash->filter_hash; |
1726 | other_hash = ops->func_hash->notrace_hash; | |
06a51d93 | 1727 | if (ftrace_hash_empty(hash)) |
8c08f0d5 | 1728 | all = true; |
ed926f9b SR |
1729 | } else { |
1730 | inc = !inc; | |
33b7f99c SRRH |
1731 | hash = ops->func_hash->notrace_hash; |
1732 | other_hash = ops->func_hash->filter_hash; | |
ed926f9b SR |
1733 | /* |
1734 | * If the notrace hash has no items, | |
1735 | * then there's nothing to do. | |
1736 | */ | |
06a51d93 | 1737 | if (ftrace_hash_empty(hash)) |
84b6d3e6 | 1738 | return false; |
ed926f9b SR |
1739 | } |
1740 | ||
1741 | do_for_each_ftrace_rec(pg, rec) { | |
1742 | int in_other_hash = 0; | |
1743 | int in_hash = 0; | |
1744 | int match = 0; | |
1745 | ||
cf04f2d5 | 1746 | if (skip_record(rec)) |
b7ffffbb SRRH |
1747 | continue; |
1748 | ||
ed926f9b SR |
1749 | if (all) { |
1750 | /* | |
1751 | * Only the filter_hash affects all records. | |
1752 | * Update if the record is not in the notrace hash. | |
1753 | */ | |
b848914c | 1754 | if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip)) |
ed926f9b SR |
1755 | match = 1; |
1756 | } else { | |
06a51d93 SR |
1757 | in_hash = !!ftrace_lookup_ip(hash, rec->ip); |
1758 | in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip); | |
ed926f9b SR |
1759 | |
1760 | /* | |
19eab4a4 SRRH |
1761 | * If filter_hash is set, we want to match all functions |
1762 | * that are in the hash but not in the other hash. | |
ed926f9b | 1763 | * |
19eab4a4 SRRH |
1764 | * If filter_hash is not set, then we are decrementing. |
1765 | * That means we match anything that is in the hash | |
1766 | * and also in the other_hash. That is, we need to turn | |
1767 | * off functions in the other hash because they are disabled | |
1768 | * by this hash. | |
ed926f9b SR |
1769 | */ |
1770 | if (filter_hash && in_hash && !in_other_hash) | |
1771 | match = 1; | |
1772 | else if (!filter_hash && in_hash && | |
06a51d93 | 1773 | (in_other_hash || ftrace_hash_empty(other_hash))) |
ed926f9b SR |
1774 | match = 1; |
1775 | } | |
1776 | if (!match) | |
1777 | continue; | |
1778 | ||
1779 | if (inc) { | |
1780 | rec->flags++; | |
0376bde1 | 1781 | if (FTRACE_WARN_ON(ftrace_rec_count(rec) == FTRACE_REF_MAX)) |
84b6d3e6 | 1782 | return false; |
79922b80 | 1783 | |
763e34e7 SRV |
1784 | if (ops->flags & FTRACE_OPS_FL_DIRECT) |
1785 | rec->flags |= FTRACE_FL_DIRECT; | |
1786 | ||
79922b80 SRRH |
1787 | /* |
1788 | * If there's only a single callback registered to a | |
1789 | * function, and the ops has a trampoline registered | |
1790 | * for it, then we can call it directly. | |
1791 | */ | |
fef5aeee | 1792 | if (ftrace_rec_count(rec) == 1 && ops->trampoline) |
79922b80 | 1793 | rec->flags |= FTRACE_FL_TRAMP; |
fef5aeee | 1794 | else |
79922b80 SRRH |
1795 | /* |
1796 | * If we are adding another function callback | |
1797 | * to this function, and the previous had a | |
bce0b6c5 SRRH |
1798 | * custom trampoline in use, then we need to go |
1799 | * back to the default trampoline. | |
79922b80 | 1800 | */ |
fef5aeee | 1801 | rec->flags &= ~FTRACE_FL_TRAMP; |
79922b80 | 1802 | |
08f6fba5 SR |
1803 | /* |
1804 | * If any ops wants regs saved for this function | |
1805 | * then all ops will get saved regs. | |
1806 | */ | |
1807 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) | |
1808 | rec->flags |= FTRACE_FL_REGS; | |
ed926f9b | 1809 | } else { |
0376bde1 | 1810 | if (FTRACE_WARN_ON(ftrace_rec_count(rec) == 0)) |
84b6d3e6 | 1811 | return false; |
ed926f9b | 1812 | rec->flags--; |
79922b80 | 1813 | |
763e34e7 SRV |
1814 | /* |
1815 | * Only the internal direct_ops should have the | |
1816 | * DIRECT flag set. Thus, if it is removing a | |
1817 | * function, then that function should no longer | |
1818 | * be direct. | |
1819 | */ | |
1820 | if (ops->flags & FTRACE_OPS_FL_DIRECT) | |
1821 | rec->flags &= ~FTRACE_FL_DIRECT; | |
1822 | ||
4fbb48cb SRRH |
1823 | /* |
1824 | * If the rec had REGS enabled and the ops that is | |
1825 | * being removed had REGS set, then see if there is | |
1826 | * still any ops for this record that wants regs. | |
1827 | * If not, we can stop recording them. | |
1828 | */ | |
0376bde1 | 1829 | if (ftrace_rec_count(rec) > 0 && |
4fbb48cb SRRH |
1830 | rec->flags & FTRACE_FL_REGS && |
1831 | ops->flags & FTRACE_OPS_FL_SAVE_REGS) { | |
1832 | if (!test_rec_ops_needs_regs(rec)) | |
1833 | rec->flags &= ~FTRACE_FL_REGS; | |
1834 | } | |
79922b80 | 1835 | |
fef5aeee | 1836 | /* |
a124692b CJ |
1837 | * The TRAMP needs to be set only if rec count |
1838 | * is decremented to one, and the ops that is | |
1839 | * left has a trampoline. As TRAMP can only be | |
1840 | * enabled if there is only a single ops attached | |
1841 | * to it. | |
fef5aeee | 1842 | */ |
a124692b | 1843 | if (ftrace_rec_count(rec) == 1 && |
4c75b0ff | 1844 | ftrace_find_tramp_ops_any_other(rec, ops)) |
a124692b CJ |
1845 | rec->flags |= FTRACE_FL_TRAMP; |
1846 | else | |
1847 | rec->flags &= ~FTRACE_FL_TRAMP; | |
fef5aeee | 1848 | |
79922b80 SRRH |
1849 | /* |
1850 | * flags will be cleared in ftrace_check_record() | |
1851 | * if rec count is zero. | |
1852 | */ | |
ed926f9b | 1853 | } |
cbad0fb2 MR |
1854 | |
1855 | /* | |
1856 | * If the rec has a single associated ops, and ops->func can be | |
1857 | * called directly, allow the call site to call via the ops. | |
1858 | */ | |
1859 | if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS) && | |
1860 | ftrace_rec_count(rec) == 1 && | |
1861 | ftrace_ops_get_func(ops) == ops->func) | |
1862 | rec->flags |= FTRACE_FL_CALL_OPS; | |
1863 | else | |
1864 | rec->flags &= ~FTRACE_FL_CALL_OPS; | |
1865 | ||
ed926f9b | 1866 | count++; |
84b6d3e6 JO |
1867 | |
1868 | /* Must match FTRACE_UPDATE_CALLS in ftrace_modify_all_code() */ | |
7375dca1 | 1869 | update |= ftrace_test_record(rec, true) != FTRACE_UPDATE_IGNORE; |
84b6d3e6 | 1870 | |
ed926f9b SR |
1871 | /* Shortcut, if we handled all records, we are done. */ |
1872 | if (!all && count == hash->count) | |
84b6d3e6 | 1873 | return update; |
ed926f9b | 1874 | } while_for_each_ftrace_rec(); |
84b6d3e6 JO |
1875 | |
1876 | return update; | |
ed926f9b SR |
1877 | } |
1878 | ||
84b6d3e6 | 1879 | static bool ftrace_hash_rec_disable(struct ftrace_ops *ops, |
ed926f9b SR |
1880 | int filter_hash) |
1881 | { | |
84b6d3e6 | 1882 | return __ftrace_hash_rec_update(ops, filter_hash, 0); |
ed926f9b SR |
1883 | } |
1884 | ||
84b6d3e6 | 1885 | static bool ftrace_hash_rec_enable(struct ftrace_ops *ops, |
ed926f9b SR |
1886 | int filter_hash) |
1887 | { | |
84b6d3e6 | 1888 | return __ftrace_hash_rec_update(ops, filter_hash, 1); |
ed926f9b SR |
1889 | } |
1890 | ||
84261912 SRRH |
1891 | static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops, |
1892 | int filter_hash, int inc) | |
1893 | { | |
1894 | struct ftrace_ops *op; | |
1895 | ||
1896 | __ftrace_hash_rec_update(ops, filter_hash, inc); | |
1897 | ||
1898 | if (ops->func_hash != &global_ops.local_hash) | |
1899 | return; | |
1900 | ||
1901 | /* | |
1902 | * If the ops shares the global_ops hash, then we need to update | |
1903 | * all ops that are enabled and use this hash. | |
1904 | */ | |
1905 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
1906 | /* Already done */ | |
1907 | if (op == ops) | |
1908 | continue; | |
1909 | if (op->func_hash == &global_ops.local_hash) | |
1910 | __ftrace_hash_rec_update(op, filter_hash, inc); | |
1911 | } while_for_each_ftrace_op(op); | |
1912 | } | |
1913 | ||
1914 | static void ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, | |
1915 | int filter_hash) | |
1916 | { | |
1917 | ftrace_hash_rec_update_modify(ops, filter_hash, 0); | |
1918 | } | |
1919 | ||
1920 | static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, | |
1921 | int filter_hash) | |
1922 | { | |
1923 | ftrace_hash_rec_update_modify(ops, filter_hash, 1); | |
1924 | } | |
1925 | ||
f8b8be8a MH |
1926 | /* |
1927 | * Try to update IPMODIFY flag on each ftrace_rec. Return 0 if it is OK | |
1928 | * or no-needed to update, -EBUSY if it detects a conflict of the flag | |
1929 | * on a ftrace_rec, and -EINVAL if the new_hash tries to trace all recs. | |
1930 | * Note that old_hash and new_hash has below meanings | |
1931 | * - If the hash is NULL, it hits all recs (if IPMODIFY is set, this is rejected) | |
1932 | * - If the hash is EMPTY_HASH, it hits nothing | |
1933 | * - Anything else hits the recs which match the hash entries. | |
53cd885b SL |
1934 | * |
1935 | * DIRECT ops does not have IPMODIFY flag, but we still need to check it | |
1936 | * against functions with FTRACE_FL_IPMODIFY. If there is any overlap, call | |
1937 | * ops_func(SHARE_IPMODIFY_SELF) to make sure current ops can share with | |
1938 | * IPMODIFY. If ops_func(SHARE_IPMODIFY_SELF) returns non-zero, propagate | |
1939 | * the return value to the caller and eventually to the owner of the DIRECT | |
1940 | * ops. | |
f8b8be8a MH |
1941 | */ |
1942 | static int __ftrace_hash_update_ipmodify(struct ftrace_ops *ops, | |
1943 | struct ftrace_hash *old_hash, | |
1944 | struct ftrace_hash *new_hash) | |
1945 | { | |
1946 | struct ftrace_page *pg; | |
1947 | struct dyn_ftrace *rec, *end = NULL; | |
1948 | int in_old, in_new; | |
53cd885b | 1949 | bool is_ipmodify, is_direct; |
f8b8be8a MH |
1950 | |
1951 | /* Only update if the ops has been registered */ | |
1952 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
1953 | return 0; | |
1954 | ||
53cd885b SL |
1955 | is_ipmodify = ops->flags & FTRACE_OPS_FL_IPMODIFY; |
1956 | is_direct = ops->flags & FTRACE_OPS_FL_DIRECT; | |
1957 | ||
1958 | /* neither IPMODIFY nor DIRECT, skip */ | |
1959 | if (!is_ipmodify && !is_direct) | |
1960 | return 0; | |
1961 | ||
1962 | if (WARN_ON_ONCE(is_ipmodify && is_direct)) | |
f8b8be8a MH |
1963 | return 0; |
1964 | ||
1965 | /* | |
53cd885b SL |
1966 | * Since the IPMODIFY and DIRECT are very address sensitive |
1967 | * actions, we do not allow ftrace_ops to set all functions to new | |
1968 | * hash. | |
f8b8be8a MH |
1969 | */ |
1970 | if (!new_hash || !old_hash) | |
1971 | return -EINVAL; | |
1972 | ||
1973 | /* Update rec->flags */ | |
1974 | do_for_each_ftrace_rec(pg, rec) { | |
546fece4 SRRH |
1975 | |
1976 | if (rec->flags & FTRACE_FL_DISABLED) | |
1977 | continue; | |
1978 | ||
f8b8be8a MH |
1979 | /* We need to update only differences of filter_hash */ |
1980 | in_old = !!ftrace_lookup_ip(old_hash, rec->ip); | |
1981 | in_new = !!ftrace_lookup_ip(new_hash, rec->ip); | |
1982 | if (in_old == in_new) | |
1983 | continue; | |
1984 | ||
1985 | if (in_new) { | |
53cd885b SL |
1986 | if (rec->flags & FTRACE_FL_IPMODIFY) { |
1987 | int ret; | |
1988 | ||
1989 | /* Cannot have two ipmodify on same rec */ | |
1990 | if (is_ipmodify) | |
1991 | goto rollback; | |
1992 | ||
1993 | FTRACE_WARN_ON(rec->flags & FTRACE_FL_DIRECT); | |
1994 | ||
1995 | /* | |
1996 | * Another ops with IPMODIFY is already | |
1997 | * attached. We are now attaching a direct | |
1998 | * ops. Run SHARE_IPMODIFY_SELF, to check | |
1999 | * whether sharing is supported. | |
2000 | */ | |
2001 | if (!ops->ops_func) | |
2002 | return -EBUSY; | |
2003 | ret = ops->ops_func(ops, FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_SELF); | |
2004 | if (ret) | |
2005 | return ret; | |
2006 | } else if (is_ipmodify) { | |
2007 | rec->flags |= FTRACE_FL_IPMODIFY; | |
2008 | } | |
2009 | } else if (is_ipmodify) { | |
f8b8be8a | 2010 | rec->flags &= ~FTRACE_FL_IPMODIFY; |
53cd885b | 2011 | } |
f8b8be8a MH |
2012 | } while_for_each_ftrace_rec(); |
2013 | ||
2014 | return 0; | |
2015 | ||
2016 | rollback: | |
2017 | end = rec; | |
2018 | ||
2019 | /* Roll back what we did above */ | |
2020 | do_for_each_ftrace_rec(pg, rec) { | |
546fece4 SRRH |
2021 | |
2022 | if (rec->flags & FTRACE_FL_DISABLED) | |
2023 | continue; | |
2024 | ||
f8b8be8a MH |
2025 | if (rec == end) |
2026 | goto err_out; | |
2027 | ||
2028 | in_old = !!ftrace_lookup_ip(old_hash, rec->ip); | |
2029 | in_new = !!ftrace_lookup_ip(new_hash, rec->ip); | |
2030 | if (in_old == in_new) | |
2031 | continue; | |
2032 | ||
2033 | if (in_new) | |
2034 | rec->flags &= ~FTRACE_FL_IPMODIFY; | |
2035 | else | |
2036 | rec->flags |= FTRACE_FL_IPMODIFY; | |
2037 | } while_for_each_ftrace_rec(); | |
2038 | ||
2039 | err_out: | |
2040 | return -EBUSY; | |
2041 | } | |
2042 | ||
2043 | static int ftrace_hash_ipmodify_enable(struct ftrace_ops *ops) | |
2044 | { | |
2045 | struct ftrace_hash *hash = ops->func_hash->filter_hash; | |
2046 | ||
2047 | if (ftrace_hash_empty(hash)) | |
2048 | hash = NULL; | |
2049 | ||
2050 | return __ftrace_hash_update_ipmodify(ops, EMPTY_HASH, hash); | |
2051 | } | |
2052 | ||
2053 | /* Disabling always succeeds */ | |
2054 | static void ftrace_hash_ipmodify_disable(struct ftrace_ops *ops) | |
2055 | { | |
2056 | struct ftrace_hash *hash = ops->func_hash->filter_hash; | |
2057 | ||
2058 | if (ftrace_hash_empty(hash)) | |
2059 | hash = NULL; | |
2060 | ||
2061 | __ftrace_hash_update_ipmodify(ops, hash, EMPTY_HASH); | |
2062 | } | |
2063 | ||
2064 | static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops, | |
2065 | struct ftrace_hash *new_hash) | |
2066 | { | |
2067 | struct ftrace_hash *old_hash = ops->func_hash->filter_hash; | |
2068 | ||
2069 | if (ftrace_hash_empty(old_hash)) | |
2070 | old_hash = NULL; | |
2071 | ||
2072 | if (ftrace_hash_empty(new_hash)) | |
2073 | new_hash = NULL; | |
2074 | ||
2075 | return __ftrace_hash_update_ipmodify(ops, old_hash, new_hash); | |
2076 | } | |
2077 | ||
b05086c7 | 2078 | static void print_ip_ins(const char *fmt, const unsigned char *p) |
b17e8a37 | 2079 | { |
6c14133d | 2080 | char ins[MCOUNT_INSN_SIZE]; |
b17e8a37 | 2081 | |
6c14133d SRV |
2082 | if (copy_from_kernel_nofault(ins, p, MCOUNT_INSN_SIZE)) { |
2083 | printk(KERN_CONT "%s[FAULT] %px\n", fmt, p); | |
2084 | return; | |
2085 | } | |
2086 | ||
b17e8a37 | 2087 | printk(KERN_CONT "%s", fmt); |
30f7d1ca | 2088 | pr_cont("%*phC", MCOUNT_INSN_SIZE, ins); |
b17e8a37 SR |
2089 | } |
2090 | ||
02a392a0 | 2091 | enum ftrace_bug_type ftrace_bug_type; |
b05086c7 | 2092 | const void *ftrace_expected; |
02a392a0 SRRH |
2093 | |
2094 | static void print_bug_type(void) | |
2095 | { | |
2096 | switch (ftrace_bug_type) { | |
2097 | case FTRACE_BUG_UNKNOWN: | |
2098 | break; | |
2099 | case FTRACE_BUG_INIT: | |
2100 | pr_info("Initializing ftrace call sites\n"); | |
2101 | break; | |
2102 | case FTRACE_BUG_NOP: | |
2103 | pr_info("Setting ftrace call site to NOP\n"); | |
2104 | break; | |
2105 | case FTRACE_BUG_CALL: | |
2106 | pr_info("Setting ftrace call site to call ftrace function\n"); | |
2107 | break; | |
2108 | case FTRACE_BUG_UPDATE: | |
2109 | pr_info("Updating ftrace call site to call a different ftrace function\n"); | |
2110 | break; | |
2111 | } | |
2112 | } | |
2113 | ||
c88fd863 SR |
2114 | /** |
2115 | * ftrace_bug - report and shutdown function tracer | |
2116 | * @failed: The failed type (EFAULT, EINVAL, EPERM) | |
4fd3279b | 2117 | * @rec: The record that failed |
c88fd863 SR |
2118 | * |
2119 | * The arch code that enables or disables the function tracing | |
2120 | * can call ftrace_bug() when it has detected a problem in | |
2121 | * modifying the code. @failed should be one of either: | |
2122 | * EFAULT - if the problem happens on reading the @ip address | |
2123 | * EINVAL - if what is read at @ip is not what was expected | |
9efb85c5 | 2124 | * EPERM - if the problem happens on writing to the @ip address |
c88fd863 | 2125 | */ |
4fd3279b | 2126 | void ftrace_bug(int failed, struct dyn_ftrace *rec) |
b17e8a37 | 2127 | { |
4fd3279b SRRH |
2128 | unsigned long ip = rec ? rec->ip : 0; |
2129 | ||
c143b775 CJ |
2130 | pr_info("------------[ ftrace bug ]------------\n"); |
2131 | ||
b17e8a37 SR |
2132 | switch (failed) { |
2133 | case -EFAULT: | |
b17e8a37 | 2134 | pr_info("ftrace faulted on modifying "); |
2062a4e8 | 2135 | print_ip_sym(KERN_INFO, ip); |
b17e8a37 SR |
2136 | break; |
2137 | case -EINVAL: | |
b17e8a37 | 2138 | pr_info("ftrace failed to modify "); |
2062a4e8 | 2139 | print_ip_sym(KERN_INFO, ip); |
b05086c7 | 2140 | print_ip_ins(" actual: ", (unsigned char *)ip); |
4fd3279b | 2141 | pr_cont("\n"); |
b05086c7 SRRH |
2142 | if (ftrace_expected) { |
2143 | print_ip_ins(" expected: ", ftrace_expected); | |
2144 | pr_cont("\n"); | |
2145 | } | |
b17e8a37 SR |
2146 | break; |
2147 | case -EPERM: | |
b17e8a37 | 2148 | pr_info("ftrace faulted on writing "); |
2062a4e8 | 2149 | print_ip_sym(KERN_INFO, ip); |
b17e8a37 SR |
2150 | break; |
2151 | default: | |
b17e8a37 | 2152 | pr_info("ftrace faulted on unknown error "); |
2062a4e8 | 2153 | print_ip_sym(KERN_INFO, ip); |
b17e8a37 | 2154 | } |
02a392a0 | 2155 | print_bug_type(); |
4fd3279b SRRH |
2156 | if (rec) { |
2157 | struct ftrace_ops *ops = NULL; | |
2158 | ||
2159 | pr_info("ftrace record flags: %lx\n", rec->flags); | |
cbad0fb2 MR |
2160 | pr_cont(" (%ld)%s%s", ftrace_rec_count(rec), |
2161 | rec->flags & FTRACE_FL_REGS ? " R" : " ", | |
2162 | rec->flags & FTRACE_FL_CALL_OPS ? " O" : " "); | |
4fd3279b SRRH |
2163 | if (rec->flags & FTRACE_FL_TRAMP_EN) { |
2164 | ops = ftrace_find_tramp_ops_any(rec); | |
39daa7b9 SRRH |
2165 | if (ops) { |
2166 | do { | |
2167 | pr_cont("\ttramp: %pS (%pS)", | |
2168 | (void *)ops->trampoline, | |
2169 | (void *)ops->func); | |
2170 | ops = ftrace_find_tramp_ops_next(rec, ops); | |
2171 | } while (ops); | |
2172 | } else | |
4fd3279b SRRH |
2173 | pr_cont("\ttramp: ERROR!"); |
2174 | ||
2175 | } | |
2176 | ip = ftrace_get_addr_curr(rec); | |
39daa7b9 | 2177 | pr_cont("\n expected tramp: %lx\n", ip); |
4fd3279b | 2178 | } |
c143b775 CJ |
2179 | |
2180 | FTRACE_WARN_ON_ONCE(1); | |
b17e8a37 SR |
2181 | } |
2182 | ||
7375dca1 | 2183 | static int ftrace_check_record(struct dyn_ftrace *rec, bool enable, bool update) |
5072c59f | 2184 | { |
64fbcd16 | 2185 | unsigned long flag = 0UL; |
e7d3737e | 2186 | |
02a392a0 SRRH |
2187 | ftrace_bug_type = FTRACE_BUG_UNKNOWN; |
2188 | ||
cf04f2d5 | 2189 | if (skip_record(rec)) |
b7ffffbb SRRH |
2190 | return FTRACE_UPDATE_IGNORE; |
2191 | ||
982c350b | 2192 | /* |
30fb6aa7 | 2193 | * If we are updating calls: |
982c350b | 2194 | * |
ed926f9b SR |
2195 | * If the record has a ref count, then we need to enable it |
2196 | * because someone is using it. | |
982c350b | 2197 | * |
ed926f9b SR |
2198 | * Otherwise we make sure its disabled. |
2199 | * | |
30fb6aa7 | 2200 | * If we are disabling calls, then disable all records that |
ed926f9b | 2201 | * are enabled. |
982c350b | 2202 | */ |
0376bde1 | 2203 | if (enable && ftrace_rec_count(rec)) |
ed926f9b | 2204 | flag = FTRACE_FL_ENABLED; |
982c350b | 2205 | |
08f6fba5 | 2206 | /* |
79922b80 SRRH |
2207 | * If enabling and the REGS flag does not match the REGS_EN, or |
2208 | * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore | |
2209 | * this record. Set flags to fail the compare against ENABLED. | |
763e34e7 | 2210 | * Same for direct calls. |
08f6fba5 | 2211 | */ |
79922b80 | 2212 | if (flag) { |
763e34e7 | 2213 | if (!(rec->flags & FTRACE_FL_REGS) != |
79922b80 SRRH |
2214 | !(rec->flags & FTRACE_FL_REGS_EN)) |
2215 | flag |= FTRACE_FL_REGS; | |
2216 | ||
763e34e7 | 2217 | if (!(rec->flags & FTRACE_FL_TRAMP) != |
79922b80 SRRH |
2218 | !(rec->flags & FTRACE_FL_TRAMP_EN)) |
2219 | flag |= FTRACE_FL_TRAMP; | |
763e34e7 SRV |
2220 | |
2221 | /* | |
2222 | * Direct calls are special, as count matters. | |
2223 | * We must test the record for direct, if the | |
2224 | * DIRECT and DIRECT_EN do not match, but only | |
2225 | * if the count is 1. That's because, if the | |
2226 | * count is something other than one, we do not | |
2227 | * want the direct enabled (it will be done via the | |
2228 | * direct helper). But if DIRECT_EN is set, and | |
2229 | * the count is not one, we need to clear it. | |
cbad0fb2 | 2230 | * |
763e34e7 SRV |
2231 | */ |
2232 | if (ftrace_rec_count(rec) == 1) { | |
2233 | if (!(rec->flags & FTRACE_FL_DIRECT) != | |
2234 | !(rec->flags & FTRACE_FL_DIRECT_EN)) | |
2235 | flag |= FTRACE_FL_DIRECT; | |
2236 | } else if (rec->flags & FTRACE_FL_DIRECT_EN) { | |
2237 | flag |= FTRACE_FL_DIRECT; | |
2238 | } | |
cbad0fb2 MR |
2239 | |
2240 | /* | |
2241 | * Ops calls are special, as count matters. | |
2242 | * As with direct calls, they must only be enabled when count | |
2243 | * is one, otherwise they'll be handled via the list ops. | |
2244 | */ | |
2245 | if (ftrace_rec_count(rec) == 1) { | |
2246 | if (!(rec->flags & FTRACE_FL_CALL_OPS) != | |
2247 | !(rec->flags & FTRACE_FL_CALL_OPS_EN)) | |
2248 | flag |= FTRACE_FL_CALL_OPS; | |
2249 | } else if (rec->flags & FTRACE_FL_CALL_OPS_EN) { | |
2250 | flag |= FTRACE_FL_CALL_OPS; | |
2251 | } | |
79922b80 | 2252 | } |
08f6fba5 | 2253 | |
64fbcd16 XG |
2254 | /* If the state of this record hasn't changed, then do nothing */ |
2255 | if ((rec->flags & FTRACE_FL_ENABLED) == flag) | |
c88fd863 | 2256 | return FTRACE_UPDATE_IGNORE; |
982c350b | 2257 | |
64fbcd16 | 2258 | if (flag) { |
08f6fba5 SR |
2259 | /* Save off if rec is being enabled (for return value) */ |
2260 | flag ^= rec->flags & FTRACE_FL_ENABLED; | |
2261 | ||
2262 | if (update) { | |
e11b521a | 2263 | rec->flags |= FTRACE_FL_ENABLED | FTRACE_FL_TOUCHED; |
08f6fba5 SR |
2264 | if (flag & FTRACE_FL_REGS) { |
2265 | if (rec->flags & FTRACE_FL_REGS) | |
2266 | rec->flags |= FTRACE_FL_REGS_EN; | |
2267 | else | |
2268 | rec->flags &= ~FTRACE_FL_REGS_EN; | |
2269 | } | |
79922b80 SRRH |
2270 | if (flag & FTRACE_FL_TRAMP) { |
2271 | if (rec->flags & FTRACE_FL_TRAMP) | |
2272 | rec->flags |= FTRACE_FL_TRAMP_EN; | |
2273 | else | |
2274 | rec->flags &= ~FTRACE_FL_TRAMP_EN; | |
2275 | } | |
d19ad077 | 2276 | |
6ce2c04f SRG |
2277 | /* Keep track of anything that modifies the function */ |
2278 | if (rec->flags & (FTRACE_FL_DIRECT | FTRACE_FL_IPMODIFY)) | |
2279 | rec->flags |= FTRACE_FL_MODIFIED; | |
2280 | ||
763e34e7 SRV |
2281 | if (flag & FTRACE_FL_DIRECT) { |
2282 | /* | |
2283 | * If there's only one user (direct_ops helper) | |
2284 | * then we can call the direct function | |
2285 | * directly (no ftrace trampoline). | |
2286 | */ | |
2287 | if (ftrace_rec_count(rec) == 1) { | |
2288 | if (rec->flags & FTRACE_FL_DIRECT) | |
2289 | rec->flags |= FTRACE_FL_DIRECT_EN; | |
2290 | else | |
2291 | rec->flags &= ~FTRACE_FL_DIRECT_EN; | |
2292 | } else { | |
2293 | /* | |
2294 | * Can only call directly if there's | |
2295 | * only one callback to the function. | |
2296 | */ | |
2297 | rec->flags &= ~FTRACE_FL_DIRECT_EN; | |
2298 | } | |
2299 | } | |
cbad0fb2 MR |
2300 | |
2301 | if (flag & FTRACE_FL_CALL_OPS) { | |
2302 | if (ftrace_rec_count(rec) == 1) { | |
2303 | if (rec->flags & FTRACE_FL_CALL_OPS) | |
2304 | rec->flags |= FTRACE_FL_CALL_OPS_EN; | |
2305 | else | |
2306 | rec->flags &= ~FTRACE_FL_CALL_OPS_EN; | |
2307 | } else { | |
2308 | /* | |
2309 | * Can only call directly if there's | |
2310 | * only one set of associated ops. | |
2311 | */ | |
2312 | rec->flags &= ~FTRACE_FL_CALL_OPS_EN; | |
2313 | } | |
2314 | } | |
08f6fba5 SR |
2315 | } |
2316 | ||
2317 | /* | |
2318 | * If this record is being updated from a nop, then | |
2319 | * return UPDATE_MAKE_CALL. | |
08f6fba5 SR |
2320 | * Otherwise, |
2321 | * return UPDATE_MODIFY_CALL to tell the caller to convert | |
f1b2f2bd | 2322 | * from the save regs, to a non-save regs function or |
79922b80 | 2323 | * vice versa, or from a trampoline call. |
08f6fba5 | 2324 | */ |
02a392a0 SRRH |
2325 | if (flag & FTRACE_FL_ENABLED) { |
2326 | ftrace_bug_type = FTRACE_BUG_CALL; | |
08f6fba5 | 2327 | return FTRACE_UPDATE_MAKE_CALL; |
02a392a0 | 2328 | } |
f1b2f2bd | 2329 | |
02a392a0 | 2330 | ftrace_bug_type = FTRACE_BUG_UPDATE; |
f1b2f2bd | 2331 | return FTRACE_UPDATE_MODIFY_CALL; |
c88fd863 SR |
2332 | } |
2333 | ||
08f6fba5 SR |
2334 | if (update) { |
2335 | /* If there's no more users, clear all flags */ | |
0376bde1 | 2336 | if (!ftrace_rec_count(rec)) |
e11b521a | 2337 | rec->flags &= FTRACE_NOCLEAR_FLAGS; |
08f6fba5 | 2338 | else |
b24d443b SRRH |
2339 | /* |
2340 | * Just disable the record, but keep the ops TRAMP | |
2341 | * and REGS states. The _EN flags must be disabled though. | |
2342 | */ | |
2343 | rec->flags &= ~(FTRACE_FL_ENABLED | FTRACE_FL_TRAMP_EN | | |
cbad0fb2 MR |
2344 | FTRACE_FL_REGS_EN | FTRACE_FL_DIRECT_EN | |
2345 | FTRACE_FL_CALL_OPS_EN); | |
08f6fba5 | 2346 | } |
c88fd863 | 2347 | |
02a392a0 | 2348 | ftrace_bug_type = FTRACE_BUG_NOP; |
c88fd863 SR |
2349 | return FTRACE_UPDATE_MAKE_NOP; |
2350 | } | |
2351 | ||
2352 | /** | |
6130722f | 2353 | * ftrace_update_record - set a record that now is tracing or not |
c88fd863 | 2354 | * @rec: the record to update |
7375dca1 | 2355 | * @enable: set to true if the record is tracing, false to force disable |
c88fd863 SR |
2356 | * |
2357 | * The records that represent all functions that can be traced need | |
2358 | * to be updated when tracing has been enabled. | |
2359 | */ | |
7375dca1 | 2360 | int ftrace_update_record(struct dyn_ftrace *rec, bool enable) |
c88fd863 | 2361 | { |
7375dca1 | 2362 | return ftrace_check_record(rec, enable, true); |
c88fd863 SR |
2363 | } |
2364 | ||
2365 | /** | |
6130722f | 2366 | * ftrace_test_record - check if the record has been enabled or not |
c88fd863 | 2367 | * @rec: the record to test |
7375dca1 | 2368 | * @enable: set to true to check if enabled, false if it is disabled |
c88fd863 SR |
2369 | * |
2370 | * The arch code may need to test if a record is already set to | |
2371 | * tracing to determine how to modify the function code that it | |
2372 | * represents. | |
2373 | */ | |
7375dca1 | 2374 | int ftrace_test_record(struct dyn_ftrace *rec, bool enable) |
c88fd863 | 2375 | { |
7375dca1 | 2376 | return ftrace_check_record(rec, enable, false); |
c88fd863 SR |
2377 | } |
2378 | ||
5fecaa04 SRRH |
2379 | static struct ftrace_ops * |
2380 | ftrace_find_tramp_ops_any(struct dyn_ftrace *rec) | |
2381 | { | |
2382 | struct ftrace_ops *op; | |
fef5aeee | 2383 | unsigned long ip = rec->ip; |
5fecaa04 SRRH |
2384 | |
2385 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
2386 | ||
2387 | if (!op->trampoline) | |
2388 | continue; | |
2389 | ||
fef5aeee | 2390 | if (hash_contains_ip(ip, op->func_hash)) |
5fecaa04 SRRH |
2391 | return op; |
2392 | } while_for_each_ftrace_op(op); | |
2393 | ||
2394 | return NULL; | |
2395 | } | |
2396 | ||
4c75b0ff NR |
2397 | static struct ftrace_ops * |
2398 | ftrace_find_tramp_ops_any_other(struct dyn_ftrace *rec, struct ftrace_ops *op_exclude) | |
2399 | { | |
2400 | struct ftrace_ops *op; | |
2401 | unsigned long ip = rec->ip; | |
2402 | ||
2403 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
2404 | ||
2405 | if (op == op_exclude || !op->trampoline) | |
2406 | continue; | |
2407 | ||
2408 | if (hash_contains_ip(ip, op->func_hash)) | |
2409 | return op; | |
2410 | } while_for_each_ftrace_op(op); | |
2411 | ||
2412 | return NULL; | |
2413 | } | |
2414 | ||
39daa7b9 SRRH |
2415 | static struct ftrace_ops * |
2416 | ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, | |
2417 | struct ftrace_ops *op) | |
2418 | { | |
2419 | unsigned long ip = rec->ip; | |
2420 | ||
2421 | while_for_each_ftrace_op(op) { | |
2422 | ||
2423 | if (!op->trampoline) | |
2424 | continue; | |
2425 | ||
2426 | if (hash_contains_ip(ip, op->func_hash)) | |
2427 | return op; | |
026bb845 | 2428 | } |
39daa7b9 SRRH |
2429 | |
2430 | return NULL; | |
2431 | } | |
2432 | ||
79922b80 SRRH |
2433 | static struct ftrace_ops * |
2434 | ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec) | |
2435 | { | |
2436 | struct ftrace_ops *op; | |
fef5aeee | 2437 | unsigned long ip = rec->ip; |
79922b80 | 2438 | |
fef5aeee SRRH |
2439 | /* |
2440 | * Need to check removed ops first. | |
2441 | * If they are being removed, and this rec has a tramp, | |
2442 | * and this rec is in the ops list, then it would be the | |
2443 | * one with the tramp. | |
2444 | */ | |
2445 | if (removed_ops) { | |
2446 | if (hash_contains_ip(ip, &removed_ops->old_hash)) | |
79922b80 SRRH |
2447 | return removed_ops; |
2448 | } | |
2449 | ||
fef5aeee SRRH |
2450 | /* |
2451 | * Need to find the current trampoline for a rec. | |
2452 | * Now, a trampoline is only attached to a rec if there | |
2453 | * was a single 'ops' attached to it. But this can be called | |
2454 | * when we are adding another op to the rec or removing the | |
2455 | * current one. Thus, if the op is being added, we can | |
2456 | * ignore it because it hasn't attached itself to the rec | |
4fc40904 SRRH |
2457 | * yet. |
2458 | * | |
2459 | * If an ops is being modified (hooking to different functions) | |
2460 | * then we don't care about the new functions that are being | |
2461 | * added, just the old ones (that are probably being removed). | |
2462 | * | |
2463 | * If we are adding an ops to a function that already is using | |
2464 | * a trampoline, it needs to be removed (trampolines are only | |
2465 | * for single ops connected), then an ops that is not being | |
2466 | * modified also needs to be checked. | |
fef5aeee | 2467 | */ |
79922b80 | 2468 | do_for_each_ftrace_op(op, ftrace_ops_list) { |
fef5aeee SRRH |
2469 | |
2470 | if (!op->trampoline) | |
2471 | continue; | |
2472 | ||
2473 | /* | |
2474 | * If the ops is being added, it hasn't gotten to | |
2475 | * the point to be removed from this tree yet. | |
2476 | */ | |
2477 | if (op->flags & FTRACE_OPS_FL_ADDING) | |
79922b80 SRRH |
2478 | continue; |
2479 | ||
4fc40904 | 2480 | |
fef5aeee | 2481 | /* |
4fc40904 SRRH |
2482 | * If the ops is being modified and is in the old |
2483 | * hash, then it is probably being removed from this | |
2484 | * function. | |
fef5aeee | 2485 | */ |
fef5aeee SRRH |
2486 | if ((op->flags & FTRACE_OPS_FL_MODIFYING) && |
2487 | hash_contains_ip(ip, &op->old_hash)) | |
79922b80 | 2488 | return op; |
4fc40904 SRRH |
2489 | /* |
2490 | * If the ops is not being added or modified, and it's | |
2491 | * in its normal filter hash, then this must be the one | |
2492 | * we want! | |
2493 | */ | |
2494 | if (!(op->flags & FTRACE_OPS_FL_MODIFYING) && | |
2495 | hash_contains_ip(ip, op->func_hash)) | |
2496 | return op; | |
79922b80 SRRH |
2497 | |
2498 | } while_for_each_ftrace_op(op); | |
2499 | ||
2500 | return NULL; | |
2501 | } | |
2502 | ||
2503 | static struct ftrace_ops * | |
2504 | ftrace_find_tramp_ops_new(struct dyn_ftrace *rec) | |
2505 | { | |
2506 | struct ftrace_ops *op; | |
fef5aeee | 2507 | unsigned long ip = rec->ip; |
79922b80 SRRH |
2508 | |
2509 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
2510 | /* pass rec in as regs to have non-NULL val */ | |
fef5aeee | 2511 | if (hash_contains_ip(ip, op->func_hash)) |
79922b80 SRRH |
2512 | return op; |
2513 | } while_for_each_ftrace_op(op); | |
2514 | ||
2515 | return NULL; | |
2516 | } | |
2517 | ||
cbad0fb2 MR |
2518 | struct ftrace_ops * |
2519 | ftrace_find_unique_ops(struct dyn_ftrace *rec) | |
2520 | { | |
2521 | struct ftrace_ops *op, *found = NULL; | |
2522 | unsigned long ip = rec->ip; | |
2523 | ||
2524 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
2525 | ||
2526 | if (hash_contains_ip(ip, op->func_hash)) { | |
2527 | if (found) | |
2528 | return NULL; | |
2529 | found = op; | |
2530 | } | |
2531 | ||
2532 | } while_for_each_ftrace_op(op); | |
2533 | ||
2534 | return found; | |
2535 | } | |
2536 | ||
763e34e7 SRV |
2537 | #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS |
2538 | /* Protected by rcu_tasks for reading, and direct_mutex for writing */ | |
d05cb470 | 2539 | static struct ftrace_hash __rcu *direct_functions = EMPTY_HASH; |
763e34e7 | 2540 | static DEFINE_MUTEX(direct_mutex); |
a3ad1a7e | 2541 | int ftrace_direct_func_count; |
763e34e7 SRV |
2542 | |
2543 | /* | |
2544 | * Search the direct_functions hash to see if the given instruction pointer | |
2545 | * has a direct caller attached to it. | |
2546 | */ | |
ff205766 | 2547 | unsigned long ftrace_find_rec_direct(unsigned long ip) |
763e34e7 SRV |
2548 | { |
2549 | struct ftrace_func_entry *entry; | |
2550 | ||
2551 | entry = __ftrace_lookup_ip(direct_functions, ip); | |
2552 | if (!entry) | |
2553 | return 0; | |
2554 | ||
2555 | return entry->direct; | |
2556 | } | |
2557 | ||
2558 | static void call_direct_funcs(unsigned long ip, unsigned long pip, | |
d19ad077 | 2559 | struct ftrace_ops *ops, struct ftrace_regs *fregs) |
763e34e7 | 2560 | { |
dbaccb61 | 2561 | unsigned long addr = READ_ONCE(ops->direct_call); |
763e34e7 | 2562 | |
763e34e7 SRV |
2563 | if (!addr) |
2564 | return; | |
2565 | ||
9705bc70 | 2566 | arch_ftrace_set_direct_caller(fregs, addr); |
763e34e7 | 2567 | } |
763e34e7 SRV |
2568 | #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ |
2569 | ||
7413af1f SRRH |
2570 | /** |
2571 | * ftrace_get_addr_new - Get the call address to set to | |
2572 | * @rec: The ftrace record descriptor | |
2573 | * | |
2574 | * If the record has the FTRACE_FL_REGS set, that means that it | |
2575 | * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS | |
5c8c206e | 2576 | * is not set, then it wants to convert to the normal callback. |
7413af1f | 2577 | * |
d1530413 | 2578 | * Returns: the address of the trampoline to set to |
7413af1f SRRH |
2579 | */ |
2580 | unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec) | |
2581 | { | |
79922b80 | 2582 | struct ftrace_ops *ops; |
763e34e7 SRV |
2583 | unsigned long addr; |
2584 | ||
2585 | if ((rec->flags & FTRACE_FL_DIRECT) && | |
2586 | (ftrace_rec_count(rec) == 1)) { | |
ff205766 | 2587 | addr = ftrace_find_rec_direct(rec->ip); |
763e34e7 SRV |
2588 | if (addr) |
2589 | return addr; | |
2590 | WARN_ON_ONCE(1); | |
2591 | } | |
79922b80 SRRH |
2592 | |
2593 | /* Trampolines take precedence over regs */ | |
2594 | if (rec->flags & FTRACE_FL_TRAMP) { | |
2595 | ops = ftrace_find_tramp_ops_new(rec); | |
2596 | if (FTRACE_WARN_ON(!ops || !ops->trampoline)) { | |
bce0b6c5 SRRH |
2597 | pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n", |
2598 | (void *)rec->ip, (void *)rec->ip, rec->flags); | |
79922b80 SRRH |
2599 | /* Ftrace is shutting down, return anything */ |
2600 | return (unsigned long)FTRACE_ADDR; | |
2601 | } | |
2602 | return ops->trampoline; | |
2603 | } | |
2604 | ||
7413af1f SRRH |
2605 | if (rec->flags & FTRACE_FL_REGS) |
2606 | return (unsigned long)FTRACE_REGS_ADDR; | |
2607 | else | |
2608 | return (unsigned long)FTRACE_ADDR; | |
2609 | } | |
2610 | ||
2611 | /** | |
2612 | * ftrace_get_addr_curr - Get the call address that is already there | |
2613 | * @rec: The ftrace record descriptor | |
2614 | * | |
2615 | * The FTRACE_FL_REGS_EN is set when the record already points to | |
2616 | * a function that saves all the regs. Basically the '_EN' version | |
2617 | * represents the current state of the function. | |
2618 | * | |
d1530413 | 2619 | * Returns: the address of the trampoline that is currently being called |
7413af1f SRRH |
2620 | */ |
2621 | unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec) | |
2622 | { | |
79922b80 | 2623 | struct ftrace_ops *ops; |
763e34e7 SRV |
2624 | unsigned long addr; |
2625 | ||
2626 | /* Direct calls take precedence over trampolines */ | |
2627 | if (rec->flags & FTRACE_FL_DIRECT_EN) { | |
ff205766 | 2628 | addr = ftrace_find_rec_direct(rec->ip); |
763e34e7 SRV |
2629 | if (addr) |
2630 | return addr; | |
2631 | WARN_ON_ONCE(1); | |
2632 | } | |
79922b80 SRRH |
2633 | |
2634 | /* Trampolines take precedence over regs */ | |
2635 | if (rec->flags & FTRACE_FL_TRAMP_EN) { | |
2636 | ops = ftrace_find_tramp_ops_curr(rec); | |
2637 | if (FTRACE_WARN_ON(!ops)) { | |
a395d6a7 JP |
2638 | pr_warn("Bad trampoline accounting at: %p (%pS)\n", |
2639 | (void *)rec->ip, (void *)rec->ip); | |
79922b80 SRRH |
2640 | /* Ftrace is shutting down, return anything */ |
2641 | return (unsigned long)FTRACE_ADDR; | |
2642 | } | |
2643 | return ops->trampoline; | |
2644 | } | |
2645 | ||
7413af1f SRRH |
2646 | if (rec->flags & FTRACE_FL_REGS_EN) |
2647 | return (unsigned long)FTRACE_REGS_ADDR; | |
2648 | else | |
2649 | return (unsigned long)FTRACE_ADDR; | |
2650 | } | |
2651 | ||
c88fd863 | 2652 | static int |
7375dca1 | 2653 | __ftrace_replace_code(struct dyn_ftrace *rec, bool enable) |
c88fd863 | 2654 | { |
08f6fba5 | 2655 | unsigned long ftrace_old_addr; |
c88fd863 SR |
2656 | unsigned long ftrace_addr; |
2657 | int ret; | |
2658 | ||
7c0868e0 | 2659 | ftrace_addr = ftrace_get_addr_new(rec); |
c88fd863 | 2660 | |
7c0868e0 SRRH |
2661 | /* This needs to be done before we call ftrace_update_record */ |
2662 | ftrace_old_addr = ftrace_get_addr_curr(rec); | |
2663 | ||
2664 | ret = ftrace_update_record(rec, enable); | |
08f6fba5 | 2665 | |
02a392a0 SRRH |
2666 | ftrace_bug_type = FTRACE_BUG_UNKNOWN; |
2667 | ||
c88fd863 SR |
2668 | switch (ret) { |
2669 | case FTRACE_UPDATE_IGNORE: | |
2670 | return 0; | |
2671 | ||
2672 | case FTRACE_UPDATE_MAKE_CALL: | |
02a392a0 | 2673 | ftrace_bug_type = FTRACE_BUG_CALL; |
64fbcd16 | 2674 | return ftrace_make_call(rec, ftrace_addr); |
c88fd863 SR |
2675 | |
2676 | case FTRACE_UPDATE_MAKE_NOP: | |
02a392a0 | 2677 | ftrace_bug_type = FTRACE_BUG_NOP; |
39b5552c | 2678 | return ftrace_make_nop(NULL, rec, ftrace_old_addr); |
08f6fba5 | 2679 | |
08f6fba5 | 2680 | case FTRACE_UPDATE_MODIFY_CALL: |
02a392a0 | 2681 | ftrace_bug_type = FTRACE_BUG_UPDATE; |
08f6fba5 | 2682 | return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr); |
5072c59f SR |
2683 | } |
2684 | ||
9efb85c5 | 2685 | return -1; /* unknown ftrace bug */ |
5072c59f SR |
2686 | } |
2687 | ||
a0572f68 | 2688 | void __weak ftrace_replace_code(int mod_flags) |
3c1720f0 | 2689 | { |
3c1720f0 SR |
2690 | struct dyn_ftrace *rec; |
2691 | struct ftrace_page *pg; | |
7375dca1 | 2692 | bool enable = mod_flags & FTRACE_MODIFY_ENABLE_FL; |
a0572f68 | 2693 | int schedulable = mod_flags & FTRACE_MODIFY_MAY_SLEEP_FL; |
6a24a244 | 2694 | int failed; |
3c1720f0 | 2695 | |
45a4a237 SR |
2696 | if (unlikely(ftrace_disabled)) |
2697 | return; | |
2698 | ||
265c831c | 2699 | do_for_each_ftrace_rec(pg, rec) { |
546fece4 | 2700 | |
cf04f2d5 | 2701 | if (skip_record(rec)) |
546fece4 SRRH |
2702 | continue; |
2703 | ||
e4f5d544 | 2704 | failed = __ftrace_replace_code(rec, enable); |
fa9d13cf | 2705 | if (failed) { |
4fd3279b | 2706 | ftrace_bug(failed, rec); |
3279ba37 SR |
2707 | /* Stop processing */ |
2708 | return; | |
3c1720f0 | 2709 | } |
a0572f68 SRV |
2710 | if (schedulable) |
2711 | cond_resched(); | |
265c831c | 2712 | } while_for_each_ftrace_rec(); |
3c1720f0 SR |
2713 | } |
2714 | ||
c88fd863 SR |
2715 | struct ftrace_rec_iter { |
2716 | struct ftrace_page *pg; | |
2717 | int index; | |
2718 | }; | |
2719 | ||
2720 | /** | |
6130722f | 2721 | * ftrace_rec_iter_start - start up iterating over traced functions |
c88fd863 | 2722 | * |
d1530413 | 2723 | * Returns: an iterator handle that is used to iterate over all |
c88fd863 SR |
2724 | * the records that represent address locations where functions |
2725 | * are traced. | |
2726 | * | |
2727 | * May return NULL if no records are available. | |
2728 | */ | |
2729 | struct ftrace_rec_iter *ftrace_rec_iter_start(void) | |
2730 | { | |
2731 | /* | |
2732 | * We only use a single iterator. | |
2733 | * Protected by the ftrace_lock mutex. | |
2734 | */ | |
2735 | static struct ftrace_rec_iter ftrace_rec_iter; | |
2736 | struct ftrace_rec_iter *iter = &ftrace_rec_iter; | |
2737 | ||
2738 | iter->pg = ftrace_pages_start; | |
2739 | iter->index = 0; | |
2740 | ||
2741 | /* Could have empty pages */ | |
2742 | while (iter->pg && !iter->pg->index) | |
2743 | iter->pg = iter->pg->next; | |
2744 | ||
2745 | if (!iter->pg) | |
2746 | return NULL; | |
2747 | ||
2748 | return iter; | |
2749 | } | |
2750 | ||
2751 | /** | |
6130722f | 2752 | * ftrace_rec_iter_next - get the next record to process. |
c88fd863 SR |
2753 | * @iter: The handle to the iterator. |
2754 | * | |
d1530413 | 2755 | * Returns: the next iterator after the given iterator @iter. |
c88fd863 SR |
2756 | */ |
2757 | struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter) | |
2758 | { | |
2759 | iter->index++; | |
2760 | ||
2761 | if (iter->index >= iter->pg->index) { | |
2762 | iter->pg = iter->pg->next; | |
2763 | iter->index = 0; | |
2764 | ||
2765 | /* Could have empty pages */ | |
2766 | while (iter->pg && !iter->pg->index) | |
2767 | iter->pg = iter->pg->next; | |
2768 | } | |
2769 | ||
2770 | if (!iter->pg) | |
2771 | return NULL; | |
2772 | ||
2773 | return iter; | |
2774 | } | |
2775 | ||
2776 | /** | |
6130722f | 2777 | * ftrace_rec_iter_record - get the record at the iterator location |
c88fd863 SR |
2778 | * @iter: The current iterator location |
2779 | * | |
d1530413 | 2780 | * Returns: the record that the current @iter is at. |
c88fd863 SR |
2781 | */ |
2782 | struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter) | |
2783 | { | |
2784 | return &iter->pg->records[iter->index]; | |
2785 | } | |
2786 | ||
492a7ea5 | 2787 | static int |
fbf6c73c | 2788 | ftrace_nop_initialize(struct module *mod, struct dyn_ftrace *rec) |
3c1720f0 | 2789 | { |
593eb8a2 | 2790 | int ret; |
3c1720f0 | 2791 | |
45a4a237 SR |
2792 | if (unlikely(ftrace_disabled)) |
2793 | return 0; | |
2794 | ||
fbf6c73c | 2795 | ret = ftrace_init_nop(mod, rec); |
593eb8a2 | 2796 | if (ret) { |
02a392a0 | 2797 | ftrace_bug_type = FTRACE_BUG_INIT; |
4fd3279b | 2798 | ftrace_bug(ret, rec); |
492a7ea5 | 2799 | return 0; |
37ad5084 | 2800 | } |
492a7ea5 | 2801 | return 1; |
3c1720f0 SR |
2802 | } |
2803 | ||
000ab691 SR |
2804 | /* |
2805 | * archs can override this function if they must do something | |
2806 | * before the modifying code is performed. | |
2807 | */ | |
3a2bfec0 | 2808 | void __weak ftrace_arch_code_modify_prepare(void) |
000ab691 | 2809 | { |
000ab691 SR |
2810 | } |
2811 | ||
2812 | /* | |
2813 | * archs can override this function if they must do something | |
2814 | * after the modifying code is performed. | |
2815 | */ | |
3a2bfec0 | 2816 | void __weak ftrace_arch_code_modify_post_process(void) |
000ab691 | 2817 | { |
000ab691 SR |
2818 | } |
2819 | ||
bd604f3d SRG |
2820 | static int update_ftrace_func(ftrace_func_t func) |
2821 | { | |
2822 | static ftrace_func_t save_func; | |
2823 | ||
2824 | /* Avoid updating if it hasn't changed */ | |
2825 | if (func == save_func) | |
2826 | return 0; | |
2827 | ||
2828 | save_func = func; | |
2829 | ||
2830 | return ftrace_update_ftrace_func(func); | |
2831 | } | |
2832 | ||
8ed3e2cf | 2833 | void ftrace_modify_all_code(int command) |
3d083395 | 2834 | { |
59338f75 | 2835 | int update = command & FTRACE_UPDATE_TRACE_FUNC; |
a0572f68 | 2836 | int mod_flags = 0; |
cd21067f | 2837 | int err = 0; |
59338f75 | 2838 | |
a0572f68 SRV |
2839 | if (command & FTRACE_MAY_SLEEP) |
2840 | mod_flags = FTRACE_MODIFY_MAY_SLEEP_FL; | |
2841 | ||
59338f75 SRRH |
2842 | /* |
2843 | * If the ftrace_caller calls a ftrace_ops func directly, | |
2844 | * we need to make sure that it only traces functions it | |
2845 | * expects to trace. When doing the switch of functions, | |
2846 | * we need to update to the ftrace_ops_list_func first | |
2847 | * before the transition between old and new calls are set, | |
2848 | * as the ftrace_ops_list_func will check the ops hashes | |
2849 | * to make sure the ops are having the right functions | |
2850 | * traced. | |
2851 | */ | |
cd21067f | 2852 | if (update) { |
bd604f3d | 2853 | err = update_ftrace_func(ftrace_ops_list_func); |
cd21067f PM |
2854 | if (FTRACE_WARN_ON(err)) |
2855 | return; | |
2856 | } | |
59338f75 | 2857 | |
8ed3e2cf | 2858 | if (command & FTRACE_UPDATE_CALLS) |
a0572f68 | 2859 | ftrace_replace_code(mod_flags | FTRACE_MODIFY_ENABLE_FL); |
8ed3e2cf | 2860 | else if (command & FTRACE_DISABLE_CALLS) |
a0572f68 | 2861 | ftrace_replace_code(mod_flags); |
d61f82d0 | 2862 | |
405e1d83 SRRH |
2863 | if (update && ftrace_trace_function != ftrace_ops_list_func) { |
2864 | function_trace_op = set_function_trace_op; | |
2865 | smp_wmb(); | |
2866 | /* If irqs are disabled, we are in stop machine */ | |
2867 | if (!irqs_disabled()) | |
2868 | smp_call_function(ftrace_sync_ipi, NULL, 1); | |
bd604f3d | 2869 | err = update_ftrace_func(ftrace_trace_function); |
cd21067f PM |
2870 | if (FTRACE_WARN_ON(err)) |
2871 | return; | |
405e1d83 | 2872 | } |
d61f82d0 | 2873 | |
8ed3e2cf | 2874 | if (command & FTRACE_START_FUNC_RET) |
cd21067f | 2875 | err = ftrace_enable_ftrace_graph_caller(); |
8ed3e2cf | 2876 | else if (command & FTRACE_STOP_FUNC_RET) |
cd21067f PM |
2877 | err = ftrace_disable_ftrace_graph_caller(); |
2878 | FTRACE_WARN_ON(err); | |
8ed3e2cf SR |
2879 | } |
2880 | ||
2881 | static int __ftrace_modify_code(void *data) | |
2882 | { | |
2883 | int *command = data; | |
2884 | ||
2885 | ftrace_modify_all_code(*command); | |
5a45cfe1 | 2886 | |
d61f82d0 | 2887 | return 0; |
3d083395 SR |
2888 | } |
2889 | ||
c88fd863 | 2890 | /** |
6130722f | 2891 | * ftrace_run_stop_machine - go back to the stop machine method |
c88fd863 SR |
2892 | * @command: The command to tell ftrace what to do |
2893 | * | |
2894 | * If an arch needs to fall back to the stop machine method, the | |
2895 | * it can call this function. | |
2896 | */ | |
2897 | void ftrace_run_stop_machine(int command) | |
2898 | { | |
2899 | stop_machine(__ftrace_modify_code, &command, NULL); | |
2900 | } | |
2901 | ||
2902 | /** | |
6130722f | 2903 | * arch_ftrace_update_code - modify the code to trace or not trace |
c88fd863 SR |
2904 | * @command: The command that needs to be done |
2905 | * | |
2906 | * Archs can override this function if it does not need to | |
2907 | * run stop_machine() to modify code. | |
2908 | */ | |
2909 | void __weak arch_ftrace_update_code(int command) | |
2910 | { | |
2911 | ftrace_run_stop_machine(command); | |
2912 | } | |
2913 | ||
e309b41d | 2914 | static void ftrace_run_update_code(int command) |
3d083395 | 2915 | { |
3a2bfec0 | 2916 | ftrace_arch_code_modify_prepare(); |
000ab691 | 2917 | |
c88fd863 SR |
2918 | /* |
2919 | * By default we use stop_machine() to modify the code. | |
2920 | * But archs can do what ever they want as long as it | |
2921 | * is safe. The stop_machine() is the safest, but also | |
2922 | * produces the most overhead. | |
2923 | */ | |
2924 | arch_ftrace_update_code(command); | |
2925 | ||
3a2bfec0 | 2926 | ftrace_arch_code_modify_post_process(); |
3d083395 SR |
2927 | } |
2928 | ||
8252ecf3 | 2929 | static void ftrace_run_modify_code(struct ftrace_ops *ops, int command, |
7485058e | 2930 | struct ftrace_ops_hash *old_hash) |
e1effa01 SRRH |
2931 | { |
2932 | ops->flags |= FTRACE_OPS_FL_MODIFYING; | |
7485058e SRRH |
2933 | ops->old_hash.filter_hash = old_hash->filter_hash; |
2934 | ops->old_hash.notrace_hash = old_hash->notrace_hash; | |
e1effa01 | 2935 | ftrace_run_update_code(command); |
8252ecf3 | 2936 | ops->old_hash.filter_hash = NULL; |
7485058e | 2937 | ops->old_hash.notrace_hash = NULL; |
e1effa01 SRRH |
2938 | ops->flags &= ~FTRACE_OPS_FL_MODIFYING; |
2939 | } | |
2940 | ||
d61f82d0 | 2941 | static ftrace_func_t saved_ftrace_func; |
60a7ecf4 | 2942 | static int ftrace_start_up; |
df4fc315 | 2943 | |
12cce594 SRRH |
2944 | void __weak arch_ftrace_trampoline_free(struct ftrace_ops *ops) |
2945 | { | |
2946 | } | |
2947 | ||
fc0ea795 AH |
2948 | /* List of trace_ops that have allocated trampolines */ |
2949 | static LIST_HEAD(ftrace_ops_trampoline_list); | |
2950 | ||
2951 | static void ftrace_add_trampoline_to_kallsyms(struct ftrace_ops *ops) | |
2952 | { | |
2953 | lockdep_assert_held(&ftrace_lock); | |
2954 | list_add_rcu(&ops->list, &ftrace_ops_trampoline_list); | |
2955 | } | |
2956 | ||
2957 | static void ftrace_remove_trampoline_from_kallsyms(struct ftrace_ops *ops) | |
2958 | { | |
2959 | lockdep_assert_held(&ftrace_lock); | |
2960 | list_del_rcu(&ops->list); | |
478ece95 | 2961 | synchronize_rcu(); |
fc0ea795 AH |
2962 | } |
2963 | ||
2964 | /* | |
2965 | * "__builtin__ftrace" is used as a module name in /proc/kallsyms for symbols | |
2966 | * for pages allocated for ftrace purposes, even though "__builtin__ftrace" is | |
2967 | * not a module. | |
2968 | */ | |
2969 | #define FTRACE_TRAMPOLINE_MOD "__builtin__ftrace" | |
2970 | #define FTRACE_TRAMPOLINE_SYM "ftrace_trampoline" | |
2971 | ||
2972 | static void ftrace_trampoline_free(struct ftrace_ops *ops) | |
2973 | { | |
2974 | if (ops && (ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP) && | |
dd9ddf46 | 2975 | ops->trampoline) { |
548e1f6c AH |
2976 | /* |
2977 | * Record the text poke event before the ksymbol unregister | |
2978 | * event. | |
2979 | */ | |
2980 | perf_event_text_poke((void *)ops->trampoline, | |
2981 | (void *)ops->trampoline, | |
2982 | ops->trampoline_size, NULL, 0); | |
dd9ddf46 AH |
2983 | perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_OOL, |
2984 | ops->trampoline, ops->trampoline_size, | |
2985 | true, FTRACE_TRAMPOLINE_SYM); | |
2986 | /* Remove from kallsyms after the perf events */ | |
fc0ea795 | 2987 | ftrace_remove_trampoline_from_kallsyms(ops); |
dd9ddf46 | 2988 | } |
fc0ea795 AH |
2989 | |
2990 | arch_ftrace_trampoline_free(ops); | |
2991 | } | |
2992 | ||
df4fc315 SR |
2993 | static void ftrace_startup_enable(int command) |
2994 | { | |
2995 | if (saved_ftrace_func != ftrace_trace_function) { | |
2996 | saved_ftrace_func = ftrace_trace_function; | |
2997 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
2998 | } | |
2999 | ||
3000 | if (!command || !ftrace_enabled) | |
3001 | return; | |
3002 | ||
3003 | ftrace_run_update_code(command); | |
3004 | } | |
d61f82d0 | 3005 | |
e1effa01 SRRH |
3006 | static void ftrace_startup_all(int command) |
3007 | { | |
3008 | update_all_ops = true; | |
3009 | ftrace_startup_enable(command); | |
3010 | update_all_ops = false; | |
3011 | } | |
3012 | ||
3306fc4a | 3013 | int ftrace_startup(struct ftrace_ops *ops, int command) |
3d083395 | 3014 | { |
8a56d776 | 3015 | int ret; |
b848914c | 3016 | |
4eebcc81 | 3017 | if (unlikely(ftrace_disabled)) |
a1cd6173 | 3018 | return -ENODEV; |
4eebcc81 | 3019 | |
8a56d776 SRRH |
3020 | ret = __register_ftrace_function(ops); |
3021 | if (ret) | |
3022 | return ret; | |
3023 | ||
60a7ecf4 | 3024 | ftrace_start_up++; |
d61f82d0 | 3025 | |
e1effa01 SRRH |
3026 | /* |
3027 | * Note that ftrace probes uses this to start up | |
3028 | * and modify functions it will probe. But we still | |
3029 | * set the ADDING flag for modification, as probes | |
3030 | * do not have trampolines. If they add them in the | |
3031 | * future, then the probes will need to distinguish | |
3032 | * between adding and updating probes. | |
3033 | */ | |
3034 | ops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_ADDING; | |
66209a5b | 3035 | |
f8b8be8a MH |
3036 | ret = ftrace_hash_ipmodify_enable(ops); |
3037 | if (ret < 0) { | |
3038 | /* Rollback registration process */ | |
3039 | __unregister_ftrace_function(ops); | |
3040 | ftrace_start_up--; | |
3041 | ops->flags &= ~FTRACE_OPS_FL_ENABLED; | |
d5e47505 MB |
3042 | if (ops->flags & FTRACE_OPS_FL_DYNAMIC) |
3043 | ftrace_trampoline_free(ops); | |
f8b8be8a MH |
3044 | return ret; |
3045 | } | |
3046 | ||
7f50d06b JO |
3047 | if (ftrace_hash_rec_enable(ops, 1)) |
3048 | command |= FTRACE_UPDATE_CALLS; | |
ed926f9b | 3049 | |
df4fc315 | 3050 | ftrace_startup_enable(command); |
a1cd6173 | 3051 | |
c3b0f72e YJ |
3052 | /* |
3053 | * If ftrace is in an undefined state, we just remove ops from list | |
3054 | * to prevent the NULL pointer, instead of totally rolling it back and | |
3055 | * free trampoline, because those actions could cause further damage. | |
3056 | */ | |
3057 | if (unlikely(ftrace_disabled)) { | |
3058 | __unregister_ftrace_function(ops); | |
3059 | return -ENODEV; | |
3060 | } | |
3061 | ||
e1effa01 SRRH |
3062 | ops->flags &= ~FTRACE_OPS_FL_ADDING; |
3063 | ||
a1cd6173 | 3064 | return 0; |
3d083395 SR |
3065 | } |
3066 | ||
3306fc4a | 3067 | int ftrace_shutdown(struct ftrace_ops *ops, int command) |
3d083395 | 3068 | { |
8a56d776 | 3069 | int ret; |
b848914c | 3070 | |
4eebcc81 | 3071 | if (unlikely(ftrace_disabled)) |
8a56d776 SRRH |
3072 | return -ENODEV; |
3073 | ||
3074 | ret = __unregister_ftrace_function(ops); | |
3075 | if (ret) | |
3076 | return ret; | |
4eebcc81 | 3077 | |
60a7ecf4 | 3078 | ftrace_start_up--; |
9ea1a153 FW |
3079 | /* |
3080 | * Just warn in case of unbalance, no need to kill ftrace, it's not | |
3081 | * critical but the ftrace_call callers may be never nopped again after | |
3082 | * further ftrace uses. | |
3083 | */ | |
3084 | WARN_ON_ONCE(ftrace_start_up < 0); | |
3085 | ||
f8b8be8a MH |
3086 | /* Disabling ipmodify never fails */ |
3087 | ftrace_hash_ipmodify_disable(ops); | |
ed926f9b | 3088 | |
7f50d06b JO |
3089 | if (ftrace_hash_rec_disable(ops, 1)) |
3090 | command |= FTRACE_UPDATE_CALLS; | |
b848914c | 3091 | |
7f50d06b | 3092 | ops->flags &= ~FTRACE_OPS_FL_ENABLED; |
3d083395 | 3093 | |
d61f82d0 SR |
3094 | if (saved_ftrace_func != ftrace_trace_function) { |
3095 | saved_ftrace_func = ftrace_trace_function; | |
3096 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
3097 | } | |
3d083395 | 3098 | |
0e792b89 LH |
3099 | if (!command || !ftrace_enabled) |
3100 | goto out; | |
d61f82d0 | 3101 | |
79922b80 SRRH |
3102 | /* |
3103 | * If the ops uses a trampoline, then it needs to be | |
3104 | * tested first on update. | |
3105 | */ | |
e1effa01 | 3106 | ops->flags |= FTRACE_OPS_FL_REMOVING; |
79922b80 SRRH |
3107 | removed_ops = ops; |
3108 | ||
fef5aeee SRRH |
3109 | /* The trampoline logic checks the old hashes */ |
3110 | ops->old_hash.filter_hash = ops->func_hash->filter_hash; | |
3111 | ops->old_hash.notrace_hash = ops->func_hash->notrace_hash; | |
3112 | ||
d61f82d0 | 3113 | ftrace_run_update_code(command); |
a4c35ed2 | 3114 | |
84bde62c SRRH |
3115 | /* |
3116 | * If there's no more ops registered with ftrace, run a | |
3117 | * sanity check to make sure all rec flags are cleared. | |
3118 | */ | |
f86f4180 CZ |
3119 | if (rcu_dereference_protected(ftrace_ops_list, |
3120 | lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) { | |
84bde62c SRRH |
3121 | struct ftrace_page *pg; |
3122 | struct dyn_ftrace *rec; | |
3123 | ||
3124 | do_for_each_ftrace_rec(pg, rec) { | |
e11b521a | 3125 | if (FTRACE_WARN_ON_ONCE(rec->flags & ~FTRACE_NOCLEAR_FLAGS)) |
84bde62c SRRH |
3126 | pr_warn(" %pS flags:%lx\n", |
3127 | (void *)rec->ip, rec->flags); | |
3128 | } while_for_each_ftrace_rec(); | |
3129 | } | |
3130 | ||
fef5aeee SRRH |
3131 | ops->old_hash.filter_hash = NULL; |
3132 | ops->old_hash.notrace_hash = NULL; | |
3133 | ||
3134 | removed_ops = NULL; | |
e1effa01 | 3135 | ops->flags &= ~FTRACE_OPS_FL_REMOVING; |
79922b80 | 3136 | |
0e792b89 | 3137 | out: |
a4c35ed2 SRRH |
3138 | /* |
3139 | * Dynamic ops may be freed, we must make sure that all | |
3140 | * callers are done before leaving this function. | |
a4c35ed2 | 3141 | */ |
b3a88803 | 3142 | if (ops->flags & FTRACE_OPS_FL_DYNAMIC) { |
0598e4f0 SRV |
3143 | /* |
3144 | * We need to do a hard force of sched synchronization. | |
3145 | * This is because we use preempt_disable() to do RCU, but | |
3146 | * the function tracers can be called where RCU is not watching | |
3147 | * (like before user_exit()). We can not rely on the RCU | |
3148 | * infrastructure to do the synchronization, thus we must do it | |
3149 | * ourselves. | |
3150 | */ | |
e5a971d7 | 3151 | synchronize_rcu_tasks_rude(); |
a4c35ed2 | 3152 | |
0598e4f0 | 3153 | /* |
fdda88d3 | 3154 | * When the kernel is preemptive, tasks can be preempted |
0598e4f0 SRV |
3155 | * while on a ftrace trampoline. Just scheduling a task on |
3156 | * a CPU is not good enough to flush them. Calling | |
f2cc020d | 3157 | * synchronize_rcu_tasks() will wait for those tasks to |
0598e4f0 SRV |
3158 | * execute and either schedule voluntarily or enter user space. |
3159 | */ | |
64ec8b6a | 3160 | synchronize_rcu_tasks(); |
0598e4f0 | 3161 | |
fc0ea795 | 3162 | ftrace_trampoline_free(ops); |
a4c35ed2 SRRH |
3163 | } |
3164 | ||
8a56d776 | 3165 | return 0; |
3d083395 SR |
3166 | } |
3167 | ||
a5a1d1c2 | 3168 | static u64 ftrace_update_time; |
3d083395 | 3169 | unsigned long ftrace_update_tot_cnt; |
da537f0a SRV |
3170 | unsigned long ftrace_number_of_pages; |
3171 | unsigned long ftrace_number_of_groups; | |
3d083395 | 3172 | |
8c4f3c3f | 3173 | static inline int ops_traces_mod(struct ftrace_ops *ops) |
f7bc8b61 | 3174 | { |
8c4f3c3f SRRH |
3175 | /* |
3176 | * Filter_hash being empty will default to trace module. | |
3177 | * But notrace hash requires a test of individual module functions. | |
3178 | */ | |
33b7f99c SRRH |
3179 | return ftrace_hash_empty(ops->func_hash->filter_hash) && |
3180 | ftrace_hash_empty(ops->func_hash->notrace_hash); | |
8c4f3c3f SRRH |
3181 | } |
3182 | ||
1dc43cf0 | 3183 | static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs) |
3d083395 | 3184 | { |
67ccddf8 | 3185 | bool init_nop = ftrace_need_init_nop(); |
85ae32ae | 3186 | struct ftrace_page *pg; |
e94142a6 | 3187 | struct dyn_ftrace *p; |
a5a1d1c2 | 3188 | u64 start, stop; |
1dc43cf0 | 3189 | unsigned long update_cnt = 0; |
b7ffffbb | 3190 | unsigned long rec_flags = 0; |
85ae32ae | 3191 | int i; |
f7bc8b61 | 3192 | |
b7ffffbb SRRH |
3193 | start = ftrace_now(raw_smp_processor_id()); |
3194 | ||
f7bc8b61 | 3195 | /* |
b7ffffbb SRRH |
3196 | * When a module is loaded, this function is called to convert |
3197 | * the calls to mcount in its text to nops, and also to create | |
3198 | * an entry in the ftrace data. Now, if ftrace is activated | |
3199 | * after this call, but before the module sets its text to | |
3200 | * read-only, the modification of enabling ftrace can fail if | |
3201 | * the read-only is done while ftrace is converting the calls. | |
3202 | * To prevent this, the module's records are set as disabled | |
3203 | * and will be enabled after the call to set the module's text | |
3204 | * to read-only. | |
f7bc8b61 | 3205 | */ |
b7ffffbb SRRH |
3206 | if (mod) |
3207 | rec_flags |= FTRACE_FL_DISABLED; | |
3d083395 | 3208 | |
1dc43cf0 | 3209 | for (pg = new_pgs; pg; pg = pg->next) { |
3d083395 | 3210 | |
85ae32ae | 3211 | for (i = 0; i < pg->index; i++) { |
8c4f3c3f | 3212 | |
85ae32ae SR |
3213 | /* If something went wrong, bail without enabling anything */ |
3214 | if (unlikely(ftrace_disabled)) | |
3215 | return -1; | |
f22f9a89 | 3216 | |
85ae32ae | 3217 | p = &pg->records[i]; |
b7ffffbb | 3218 | p->flags = rec_flags; |
f22f9a89 | 3219 | |
85ae32ae SR |
3220 | /* |
3221 | * Do the initial record conversion from mcount jump | |
3222 | * to the NOP instructions. | |
3223 | */ | |
67ccddf8 | 3224 | if (init_nop && !ftrace_nop_initialize(mod, p)) |
85ae32ae | 3225 | break; |
5cb084bb | 3226 | |
1dc43cf0 | 3227 | update_cnt++; |
5cb084bb | 3228 | } |
3d083395 SR |
3229 | } |
3230 | ||
750ed1a4 | 3231 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 | 3232 | ftrace_update_time = stop - start; |
1dc43cf0 | 3233 | ftrace_update_tot_cnt += update_cnt; |
3d083395 | 3234 | |
16444a8a ACM |
3235 | return 0; |
3236 | } | |
3237 | ||
a7900875 | 3238 | static int ftrace_allocate_records(struct ftrace_page *pg, int count) |
3c1720f0 | 3239 | { |
a7900875 | 3240 | int order; |
7ba031e8 | 3241 | int pages; |
3c1720f0 | 3242 | int cnt; |
3c1720f0 | 3243 | |
a7900875 SR |
3244 | if (WARN_ON(!count)) |
3245 | return -EINVAL; | |
3246 | ||
ceaaa129 | 3247 | /* We want to fill as much as possible, with no empty pages */ |
b40c6eab | 3248 | pages = DIV_ROUND_UP(count, ENTRIES_PER_PAGE); |
ceaaa129 | 3249 | order = fls(pages) - 1; |
3c1720f0 | 3250 | |
a7900875 SR |
3251 | again: |
3252 | pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order); | |
3c1720f0 | 3253 | |
a7900875 SR |
3254 | if (!pg->records) { |
3255 | /* if we can't allocate this size, try something smaller */ | |
3256 | if (!order) | |
3257 | return -ENOMEM; | |
bcea02b0 | 3258 | order--; |
a7900875 SR |
3259 | goto again; |
3260 | } | |
3c1720f0 | 3261 | |
da537f0a SRV |
3262 | ftrace_number_of_pages += 1 << order; |
3263 | ftrace_number_of_groups++; | |
3264 | ||
a7900875 | 3265 | cnt = (PAGE_SIZE << order) / ENTRY_SIZE; |
db42523b | 3266 | pg->order = order; |
3c1720f0 | 3267 | |
a7900875 SR |
3268 | if (cnt > count) |
3269 | cnt = count; | |
3270 | ||
3271 | return cnt; | |
3272 | } | |
3273 | ||
26efd79c ZY |
3274 | static void ftrace_free_pages(struct ftrace_page *pages) |
3275 | { | |
3276 | struct ftrace_page *pg = pages; | |
3277 | ||
3278 | while (pg) { | |
3279 | if (pg->records) { | |
3280 | free_pages((unsigned long)pg->records, pg->order); | |
3281 | ftrace_number_of_pages -= 1 << pg->order; | |
3282 | } | |
3283 | pages = pg->next; | |
3284 | kfree(pg); | |
3285 | pg = pages; | |
3286 | ftrace_number_of_groups--; | |
3287 | } | |
3288 | } | |
3289 | ||
a7900875 SR |
3290 | static struct ftrace_page * |
3291 | ftrace_allocate_pages(unsigned long num_to_init) | |
3292 | { | |
3293 | struct ftrace_page *start_pg; | |
3294 | struct ftrace_page *pg; | |
a7900875 SR |
3295 | int cnt; |
3296 | ||
3297 | if (!num_to_init) | |
9efb85c5 | 3298 | return NULL; |
a7900875 SR |
3299 | |
3300 | start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL); | |
3301 | if (!pg) | |
3302 | return NULL; | |
3303 | ||
3304 | /* | |
3305 | * Try to allocate as much as possible in one continues | |
3306 | * location that fills in all of the space. We want to | |
3307 | * waste as little space as possible. | |
3308 | */ | |
3309 | for (;;) { | |
3310 | cnt = ftrace_allocate_records(pg, num_to_init); | |
3311 | if (cnt < 0) | |
3312 | goto free_pages; | |
3313 | ||
3314 | num_to_init -= cnt; | |
3315 | if (!num_to_init) | |
3c1720f0 SR |
3316 | break; |
3317 | ||
a7900875 SR |
3318 | pg->next = kzalloc(sizeof(*pg), GFP_KERNEL); |
3319 | if (!pg->next) | |
3320 | goto free_pages; | |
3321 | ||
3c1720f0 SR |
3322 | pg = pg->next; |
3323 | } | |
3324 | ||
a7900875 SR |
3325 | return start_pg; |
3326 | ||
3327 | free_pages: | |
26efd79c | 3328 | ftrace_free_pages(start_pg); |
a7900875 SR |
3329 | pr_info("ftrace: FAILED to allocate memory for functions\n"); |
3330 | return NULL; | |
3331 | } | |
3332 | ||
5072c59f SR |
3333 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ |
3334 | ||
3335 | struct ftrace_iterator { | |
98c4fd04 | 3336 | loff_t pos; |
4aeb6967 | 3337 | loff_t func_pos; |
5985ea8b | 3338 | loff_t mod_pos; |
4aeb6967 SR |
3339 | struct ftrace_page *pg; |
3340 | struct dyn_ftrace *func; | |
3341 | struct ftrace_func_probe *probe; | |
eee8ded1 | 3342 | struct ftrace_func_entry *probe_entry; |
4aeb6967 | 3343 | struct trace_parser parser; |
1cf41dd7 | 3344 | struct ftrace_hash *hash; |
33dc9b12 | 3345 | struct ftrace_ops *ops; |
5985ea8b SRV |
3346 | struct trace_array *tr; |
3347 | struct list_head *mod_list; | |
eee8ded1 | 3348 | int pidx; |
4aeb6967 SR |
3349 | int idx; |
3350 | unsigned flags; | |
5072c59f SR |
3351 | }; |
3352 | ||
8fc0c701 | 3353 | static void * |
eee8ded1 | 3354 | t_probe_next(struct seq_file *m, loff_t *pos) |
8fc0c701 SR |
3355 | { |
3356 | struct ftrace_iterator *iter = m->private; | |
d2afd57a | 3357 | struct trace_array *tr = iter->ops->private; |
04ec7bb6 | 3358 | struct list_head *func_probes; |
eee8ded1 SRV |
3359 | struct ftrace_hash *hash; |
3360 | struct list_head *next; | |
4aeb6967 | 3361 | struct hlist_node *hnd = NULL; |
8fc0c701 | 3362 | struct hlist_head *hhd; |
eee8ded1 | 3363 | int size; |
8fc0c701 | 3364 | |
8fc0c701 | 3365 | (*pos)++; |
98c4fd04 | 3366 | iter->pos = *pos; |
8fc0c701 | 3367 | |
04ec7bb6 | 3368 | if (!tr) |
8fc0c701 SR |
3369 | return NULL; |
3370 | ||
04ec7bb6 SRV |
3371 | func_probes = &tr->func_probes; |
3372 | if (list_empty(func_probes)) | |
8fc0c701 SR |
3373 | return NULL; |
3374 | ||
eee8ded1 | 3375 | if (!iter->probe) { |
04ec7bb6 | 3376 | next = func_probes->next; |
7b60f3d8 | 3377 | iter->probe = list_entry(next, struct ftrace_func_probe, list); |
eee8ded1 SRV |
3378 | } |
3379 | ||
3380 | if (iter->probe_entry) | |
3381 | hnd = &iter->probe_entry->hlist; | |
3382 | ||
3383 | hash = iter->probe->ops.func_hash->filter_hash; | |
7bd46644 | 3384 | |
372e0d01 SRV |
3385 | /* |
3386 | * A probe being registered may temporarily have an empty hash | |
3387 | * and it's at the end of the func_probes list. | |
3388 | */ | |
3389 | if (!hash || hash == EMPTY_HASH) | |
7bd46644 NR |
3390 | return NULL; |
3391 | ||
eee8ded1 SRV |
3392 | size = 1 << hash->size_bits; |
3393 | ||
3394 | retry: | |
3395 | if (iter->pidx >= size) { | |
04ec7bb6 | 3396 | if (iter->probe->list.next == func_probes) |
eee8ded1 SRV |
3397 | return NULL; |
3398 | next = iter->probe->list.next; | |
7b60f3d8 | 3399 | iter->probe = list_entry(next, struct ftrace_func_probe, list); |
eee8ded1 SRV |
3400 | hash = iter->probe->ops.func_hash->filter_hash; |
3401 | size = 1 << hash->size_bits; | |
3402 | iter->pidx = 0; | |
3403 | } | |
3404 | ||
3405 | hhd = &hash->buckets[iter->pidx]; | |
8fc0c701 SR |
3406 | |
3407 | if (hlist_empty(hhd)) { | |
eee8ded1 | 3408 | iter->pidx++; |
8fc0c701 SR |
3409 | hnd = NULL; |
3410 | goto retry; | |
3411 | } | |
3412 | ||
3413 | if (!hnd) | |
3414 | hnd = hhd->first; | |
3415 | else { | |
3416 | hnd = hnd->next; | |
3417 | if (!hnd) { | |
eee8ded1 | 3418 | iter->pidx++; |
8fc0c701 SR |
3419 | goto retry; |
3420 | } | |
3421 | } | |
3422 | ||
4aeb6967 SR |
3423 | if (WARN_ON_ONCE(!hnd)) |
3424 | return NULL; | |
3425 | ||
eee8ded1 | 3426 | iter->probe_entry = hlist_entry(hnd, struct ftrace_func_entry, hlist); |
4aeb6967 SR |
3427 | |
3428 | return iter; | |
8fc0c701 SR |
3429 | } |
3430 | ||
eee8ded1 | 3431 | static void *t_probe_start(struct seq_file *m, loff_t *pos) |
8fc0c701 SR |
3432 | { |
3433 | struct ftrace_iterator *iter = m->private; | |
3434 | void *p = NULL; | |
d82d6244 LZ |
3435 | loff_t l; |
3436 | ||
eee8ded1 | 3437 | if (!(iter->flags & FTRACE_ITER_DO_PROBES)) |
69a3083c SR |
3438 | return NULL; |
3439 | ||
5985ea8b | 3440 | if (iter->mod_pos > *pos) |
2bccfffd | 3441 | return NULL; |
8fc0c701 | 3442 | |
eee8ded1 SRV |
3443 | iter->probe = NULL; |
3444 | iter->probe_entry = NULL; | |
3445 | iter->pidx = 0; | |
5985ea8b | 3446 | for (l = 0; l <= (*pos - iter->mod_pos); ) { |
eee8ded1 | 3447 | p = t_probe_next(m, &l); |
d82d6244 LZ |
3448 | if (!p) |
3449 | break; | |
3450 | } | |
4aeb6967 SR |
3451 | if (!p) |
3452 | return NULL; | |
3453 | ||
98c4fd04 | 3454 | /* Only set this if we have an item */ |
eee8ded1 | 3455 | iter->flags |= FTRACE_ITER_PROBE; |
98c4fd04 | 3456 | |
4aeb6967 | 3457 | return iter; |
8fc0c701 SR |
3458 | } |
3459 | ||
4aeb6967 | 3460 | static int |
eee8ded1 | 3461 | t_probe_show(struct seq_file *m, struct ftrace_iterator *iter) |
8fc0c701 | 3462 | { |
eee8ded1 | 3463 | struct ftrace_func_entry *probe_entry; |
7b60f3d8 SRV |
3464 | struct ftrace_probe_ops *probe_ops; |
3465 | struct ftrace_func_probe *probe; | |
8fc0c701 | 3466 | |
eee8ded1 SRV |
3467 | probe = iter->probe; |
3468 | probe_entry = iter->probe_entry; | |
8fc0c701 | 3469 | |
eee8ded1 | 3470 | if (WARN_ON_ONCE(!probe || !probe_entry)) |
4aeb6967 | 3471 | return -EIO; |
8fc0c701 | 3472 | |
7b60f3d8 | 3473 | probe_ops = probe->probe_ops; |
809dcf29 | 3474 | |
7b60f3d8 | 3475 | if (probe_ops->print) |
6e444319 | 3476 | return probe_ops->print(m, probe_entry->ip, probe_ops, probe->data); |
8fc0c701 | 3477 | |
7b60f3d8 SRV |
3478 | seq_printf(m, "%ps:%ps\n", (void *)probe_entry->ip, |
3479 | (void *)probe_ops->func); | |
8fc0c701 SR |
3480 | |
3481 | return 0; | |
3482 | } | |
3483 | ||
5985ea8b SRV |
3484 | static void * |
3485 | t_mod_next(struct seq_file *m, loff_t *pos) | |
3486 | { | |
3487 | struct ftrace_iterator *iter = m->private; | |
3488 | struct trace_array *tr = iter->tr; | |
3489 | ||
3490 | (*pos)++; | |
3491 | iter->pos = *pos; | |
3492 | ||
3493 | iter->mod_list = iter->mod_list->next; | |
3494 | ||
3495 | if (iter->mod_list == &tr->mod_trace || | |
3496 | iter->mod_list == &tr->mod_notrace) { | |
3497 | iter->flags &= ~FTRACE_ITER_MOD; | |
3498 | return NULL; | |
3499 | } | |
3500 | ||
3501 | iter->mod_pos = *pos; | |
3502 | ||
3503 | return iter; | |
3504 | } | |
3505 | ||
3506 | static void *t_mod_start(struct seq_file *m, loff_t *pos) | |
3507 | { | |
3508 | struct ftrace_iterator *iter = m->private; | |
3509 | void *p = NULL; | |
3510 | loff_t l; | |
3511 | ||
3512 | if (iter->func_pos > *pos) | |
3513 | return NULL; | |
3514 | ||
3515 | iter->mod_pos = iter->func_pos; | |
3516 | ||
3517 | /* probes are only available if tr is set */ | |
3518 | if (!iter->tr) | |
3519 | return NULL; | |
3520 | ||
3521 | for (l = 0; l <= (*pos - iter->func_pos); ) { | |
3522 | p = t_mod_next(m, &l); | |
3523 | if (!p) | |
3524 | break; | |
3525 | } | |
3526 | if (!p) { | |
3527 | iter->flags &= ~FTRACE_ITER_MOD; | |
3528 | return t_probe_start(m, pos); | |
3529 | } | |
3530 | ||
3531 | /* Only set this if we have an item */ | |
3532 | iter->flags |= FTRACE_ITER_MOD; | |
3533 | ||
3534 | return iter; | |
3535 | } | |
3536 | ||
3537 | static int | |
3538 | t_mod_show(struct seq_file *m, struct ftrace_iterator *iter) | |
3539 | { | |
3540 | struct ftrace_mod_load *ftrace_mod; | |
3541 | struct trace_array *tr = iter->tr; | |
3542 | ||
3543 | if (WARN_ON_ONCE(!iter->mod_list) || | |
3544 | iter->mod_list == &tr->mod_trace || | |
3545 | iter->mod_list == &tr->mod_notrace) | |
3546 | return -EIO; | |
3547 | ||
3548 | ftrace_mod = list_entry(iter->mod_list, struct ftrace_mod_load, list); | |
3549 | ||
3550 | if (ftrace_mod->func) | |
3551 | seq_printf(m, "%s", ftrace_mod->func); | |
3552 | else | |
3553 | seq_putc(m, '*'); | |
3554 | ||
3555 | seq_printf(m, ":mod:%s\n", ftrace_mod->module); | |
3556 | ||
3557 | return 0; | |
3558 | } | |
3559 | ||
e309b41d | 3560 | static void * |
5bd84629 | 3561 | t_func_next(struct seq_file *m, loff_t *pos) |
5072c59f SR |
3562 | { |
3563 | struct ftrace_iterator *iter = m->private; | |
3564 | struct dyn_ftrace *rec = NULL; | |
3565 | ||
3566 | (*pos)++; | |
0c75a3ed | 3567 | |
5072c59f SR |
3568 | retry: |
3569 | if (iter->idx >= iter->pg->index) { | |
3570 | if (iter->pg->next) { | |
3571 | iter->pg = iter->pg->next; | |
3572 | iter->idx = 0; | |
3573 | goto retry; | |
3574 | } | |
3575 | } else { | |
3576 | rec = &iter->pg->records[iter->idx++]; | |
c20489da SRV |
3577 | if (((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) && |
3578 | !ftrace_lookup_ip(iter->hash, rec->ip)) || | |
647bcd03 SR |
3579 | |
3580 | ((iter->flags & FTRACE_ITER_ENABLED) && | |
e11b521a SRG |
3581 | !(rec->flags & FTRACE_FL_ENABLED)) || |
3582 | ||
3583 | ((iter->flags & FTRACE_ITER_TOUCHED) && | |
3584 | !(rec->flags & FTRACE_FL_TOUCHED))) { | |
647bcd03 | 3585 | |
5072c59f SR |
3586 | rec = NULL; |
3587 | goto retry; | |
3588 | } | |
3589 | } | |
3590 | ||
4aeb6967 | 3591 | if (!rec) |
5bd84629 | 3592 | return NULL; |
4aeb6967 | 3593 | |
5bd84629 | 3594 | iter->pos = iter->func_pos = *pos; |
4aeb6967 SR |
3595 | iter->func = rec; |
3596 | ||
3597 | return iter; | |
5072c59f SR |
3598 | } |
3599 | ||
5bd84629 SRV |
3600 | static void * |
3601 | t_next(struct seq_file *m, void *v, loff_t *pos) | |
3602 | { | |
3603 | struct ftrace_iterator *iter = m->private; | |
5985ea8b | 3604 | loff_t l = *pos; /* t_probe_start() must use original pos */ |
5bd84629 SRV |
3605 | void *ret; |
3606 | ||
3607 | if (unlikely(ftrace_disabled)) | |
3608 | return NULL; | |
3609 | ||
eee8ded1 SRV |
3610 | if (iter->flags & FTRACE_ITER_PROBE) |
3611 | return t_probe_next(m, pos); | |
5bd84629 | 3612 | |
5985ea8b SRV |
3613 | if (iter->flags & FTRACE_ITER_MOD) |
3614 | return t_mod_next(m, pos); | |
3615 | ||
5bd84629 | 3616 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
eee8ded1 | 3617 | /* next must increment pos, and t_probe_start does not */ |
5bd84629 | 3618 | (*pos)++; |
5985ea8b | 3619 | return t_mod_start(m, &l); |
5bd84629 SRV |
3620 | } |
3621 | ||
3622 | ret = t_func_next(m, pos); | |
3623 | ||
3624 | if (!ret) | |
5985ea8b | 3625 | return t_mod_start(m, &l); |
5bd84629 SRV |
3626 | |
3627 | return ret; | |
3628 | } | |
3629 | ||
98c4fd04 SR |
3630 | static void reset_iter_read(struct ftrace_iterator *iter) |
3631 | { | |
3632 | iter->pos = 0; | |
3633 | iter->func_pos = 0; | |
5985ea8b | 3634 | iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_PROBE | FTRACE_ITER_MOD); |
5072c59f SR |
3635 | } |
3636 | ||
3637 | static void *t_start(struct seq_file *m, loff_t *pos) | |
3638 | { | |
3639 | struct ftrace_iterator *iter = m->private; | |
3640 | void *p = NULL; | |
694ce0a5 | 3641 | loff_t l; |
5072c59f | 3642 | |
8fc0c701 | 3643 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
3644 | |
3645 | if (unlikely(ftrace_disabled)) | |
3646 | return NULL; | |
3647 | ||
98c4fd04 SR |
3648 | /* |
3649 | * If an lseek was done, then reset and start from beginning. | |
3650 | */ | |
3651 | if (*pos < iter->pos) | |
3652 | reset_iter_read(iter); | |
3653 | ||
0c75a3ed SR |
3654 | /* |
3655 | * For set_ftrace_filter reading, if we have the filter | |
3656 | * off, we can short cut and just print out that all | |
3657 | * functions are enabled. | |
3658 | */ | |
c20489da SRV |
3659 | if ((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) && |
3660 | ftrace_hash_empty(iter->hash)) { | |
43ff926a | 3661 | iter->func_pos = 1; /* Account for the message */ |
0c75a3ed | 3662 | if (*pos > 0) |
5985ea8b | 3663 | return t_mod_start(m, pos); |
0c75a3ed | 3664 | iter->flags |= FTRACE_ITER_PRINTALL; |
df091625 | 3665 | /* reset in case of seek/pread */ |
eee8ded1 | 3666 | iter->flags &= ~FTRACE_ITER_PROBE; |
0c75a3ed SR |
3667 | return iter; |
3668 | } | |
3669 | ||
5985ea8b SRV |
3670 | if (iter->flags & FTRACE_ITER_MOD) |
3671 | return t_mod_start(m, pos); | |
8fc0c701 | 3672 | |
98c4fd04 SR |
3673 | /* |
3674 | * Unfortunately, we need to restart at ftrace_pages_start | |
3675 | * every time we let go of the ftrace_mutex. This is because | |
3676 | * those pointers can change without the lock. | |
3677 | */ | |
694ce0a5 LZ |
3678 | iter->pg = ftrace_pages_start; |
3679 | iter->idx = 0; | |
3680 | for (l = 0; l <= *pos; ) { | |
5bd84629 | 3681 | p = t_func_next(m, &l); |
694ce0a5 LZ |
3682 | if (!p) |
3683 | break; | |
50cdaf08 | 3684 | } |
5821e1b7 | 3685 | |
69a3083c | 3686 | if (!p) |
5985ea8b | 3687 | return t_mod_start(m, pos); |
4aeb6967 SR |
3688 | |
3689 | return iter; | |
5072c59f SR |
3690 | } |
3691 | ||
3692 | static void t_stop(struct seq_file *m, void *p) | |
3693 | { | |
8fc0c701 | 3694 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
3695 | } |
3696 | ||
15d5b02c SRRH |
3697 | void * __weak |
3698 | arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec) | |
3699 | { | |
3700 | return NULL; | |
3701 | } | |
3702 | ||
3703 | static void add_trampoline_func(struct seq_file *m, struct ftrace_ops *ops, | |
3704 | struct dyn_ftrace *rec) | |
3705 | { | |
3706 | void *ptr; | |
3707 | ||
3708 | ptr = arch_ftrace_trampoline_func(ops, rec); | |
3709 | if (ptr) | |
3710 | seq_printf(m, " ->%pS", ptr); | |
3711 | } | |
3712 | ||
b39181f7 SRG |
3713 | #ifdef FTRACE_MCOUNT_MAX_OFFSET |
3714 | /* | |
3715 | * Weak functions can still have an mcount/fentry that is saved in | |
3716 | * the __mcount_loc section. These can be detected by having a | |
3717 | * symbol offset of greater than FTRACE_MCOUNT_MAX_OFFSET, as the | |
3718 | * symbol found by kallsyms is not the function that the mcount/fentry | |
3719 | * is part of. The offset is much greater in these cases. | |
3720 | * | |
3721 | * Test the record to make sure that the ip points to a valid kallsyms | |
3722 | * and if not, mark it disabled. | |
3723 | */ | |
3724 | static int test_for_valid_rec(struct dyn_ftrace *rec) | |
3725 | { | |
3726 | char str[KSYM_SYMBOL_LEN]; | |
3727 | unsigned long offset; | |
3728 | const char *ret; | |
3729 | ||
3730 | ret = kallsyms_lookup(rec->ip, NULL, &offset, NULL, str); | |
3731 | ||
3732 | /* Weak functions can cause invalid addresses */ | |
3733 | if (!ret || offset > FTRACE_MCOUNT_MAX_OFFSET) { | |
3734 | rec->flags |= FTRACE_FL_DISABLED; | |
3735 | return 0; | |
3736 | } | |
3737 | return 1; | |
3738 | } | |
3739 | ||
3740 | static struct workqueue_struct *ftrace_check_wq __initdata; | |
3741 | static struct work_struct ftrace_check_work __initdata; | |
3742 | ||
3743 | /* | |
3744 | * Scan all the mcount/fentry entries to make sure they are valid. | |
3745 | */ | |
3746 | static __init void ftrace_check_work_func(struct work_struct *work) | |
3747 | { | |
3748 | struct ftrace_page *pg; | |
3749 | struct dyn_ftrace *rec; | |
3750 | ||
3751 | mutex_lock(&ftrace_lock); | |
3752 | do_for_each_ftrace_rec(pg, rec) { | |
3753 | test_for_valid_rec(rec); | |
3754 | } while_for_each_ftrace_rec(); | |
3755 | mutex_unlock(&ftrace_lock); | |
3756 | } | |
3757 | ||
3758 | static int __init ftrace_check_for_weak_functions(void) | |
3759 | { | |
3760 | INIT_WORK(&ftrace_check_work, ftrace_check_work_func); | |
3761 | ||
3762 | ftrace_check_wq = alloc_workqueue("ftrace_check_wq", WQ_UNBOUND, 0); | |
3763 | ||
3764 | queue_work(ftrace_check_wq, &ftrace_check_work); | |
3765 | return 0; | |
3766 | } | |
3767 | ||
3768 | static int __init ftrace_check_sync(void) | |
3769 | { | |
3770 | /* Make sure the ftrace_check updates are finished */ | |
3771 | if (ftrace_check_wq) | |
3772 | destroy_workqueue(ftrace_check_wq); | |
3773 | return 0; | |
3774 | } | |
3775 | ||
3776 | late_initcall_sync(ftrace_check_sync); | |
3777 | subsys_initcall(ftrace_check_for_weak_functions); | |
3778 | ||
3779 | static int print_rec(struct seq_file *m, unsigned long ip) | |
3780 | { | |
3781 | unsigned long offset; | |
3782 | char str[KSYM_SYMBOL_LEN]; | |
3783 | char *modname; | |
3784 | const char *ret; | |
3785 | ||
3786 | ret = kallsyms_lookup(ip, NULL, &offset, &modname, str); | |
3787 | /* Weak functions can cause invalid addresses */ | |
3788 | if (!ret || offset > FTRACE_MCOUNT_MAX_OFFSET) { | |
3789 | snprintf(str, KSYM_SYMBOL_LEN, "%s_%ld", | |
3790 | FTRACE_INVALID_FUNCTION, offset); | |
3791 | ret = NULL; | |
3792 | } | |
3793 | ||
3794 | seq_puts(m, str); | |
3795 | if (modname) | |
3796 | seq_printf(m, " [%s]", modname); | |
3797 | return ret == NULL ? -1 : 0; | |
3798 | } | |
3799 | #else | |
3800 | static inline int test_for_valid_rec(struct dyn_ftrace *rec) | |
3801 | { | |
3802 | return 1; | |
3803 | } | |
3804 | ||
3805 | static inline int print_rec(struct seq_file *m, unsigned long ip) | |
3806 | { | |
3807 | seq_printf(m, "%ps", (void *)ip); | |
3808 | return 0; | |
3809 | } | |
3810 | #endif | |
3811 | ||
5072c59f SR |
3812 | static int t_show(struct seq_file *m, void *v) |
3813 | { | |
0c75a3ed | 3814 | struct ftrace_iterator *iter = m->private; |
4aeb6967 | 3815 | struct dyn_ftrace *rec; |
5072c59f | 3816 | |
eee8ded1 SRV |
3817 | if (iter->flags & FTRACE_ITER_PROBE) |
3818 | return t_probe_show(m, iter); | |
8fc0c701 | 3819 | |
5985ea8b SRV |
3820 | if (iter->flags & FTRACE_ITER_MOD) |
3821 | return t_mod_show(m, iter); | |
3822 | ||
0c75a3ed | 3823 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
8c006cf7 | 3824 | if (iter->flags & FTRACE_ITER_NOTRACE) |
fa6f0cc7 | 3825 | seq_puts(m, "#### no functions disabled ####\n"); |
8c006cf7 | 3826 | else |
fa6f0cc7 | 3827 | seq_puts(m, "#### all functions enabled ####\n"); |
0c75a3ed SR |
3828 | return 0; |
3829 | } | |
3830 | ||
4aeb6967 SR |
3831 | rec = iter->func; |
3832 | ||
5072c59f SR |
3833 | if (!rec) |
3834 | return 0; | |
3835 | ||
83f74441 JO |
3836 | if (iter->flags & FTRACE_ITER_ADDRS) |
3837 | seq_printf(m, "%lx ", rec->ip); | |
3838 | ||
b39181f7 SRG |
3839 | if (print_rec(m, rec->ip)) { |
3840 | /* This should only happen when a rec is disabled */ | |
3841 | WARN_ON_ONCE(!(rec->flags & FTRACE_FL_DISABLED)); | |
3842 | seq_putc(m, '\n'); | |
3843 | return 0; | |
3844 | } | |
3845 | ||
e11b521a | 3846 | if (iter->flags & (FTRACE_ITER_ENABLED | FTRACE_ITER_TOUCHED)) { |
030f4e1c | 3847 | struct ftrace_ops *ops; |
15d5b02c | 3848 | |
6ce2c04f | 3849 | seq_printf(m, " (%ld)%s%s%s%s%s", |
0376bde1 | 3850 | ftrace_rec_count(rec), |
f8b8be8a | 3851 | rec->flags & FTRACE_FL_REGS ? " R" : " ", |
763e34e7 | 3852 | rec->flags & FTRACE_FL_IPMODIFY ? " I" : " ", |
cbad0fb2 | 3853 | rec->flags & FTRACE_FL_DIRECT ? " D" : " ", |
6ce2c04f SRG |
3854 | rec->flags & FTRACE_FL_CALL_OPS ? " O" : " ", |
3855 | rec->flags & FTRACE_FL_MODIFIED ? " M " : " "); | |
9674b2fa | 3856 | if (rec->flags & FTRACE_FL_TRAMP_EN) { |
5fecaa04 | 3857 | ops = ftrace_find_tramp_ops_any(rec); |
39daa7b9 SRRH |
3858 | if (ops) { |
3859 | do { | |
3860 | seq_printf(m, "\ttramp: %pS (%pS)", | |
3861 | (void *)ops->trampoline, | |
3862 | (void *)ops->func); | |
030f4e1c | 3863 | add_trampoline_func(m, ops, rec); |
39daa7b9 SRRH |
3864 | ops = ftrace_find_tramp_ops_next(rec, ops); |
3865 | } while (ops); | |
3866 | } else | |
fa6f0cc7 | 3867 | seq_puts(m, "\ttramp: ERROR!"); |
030f4e1c SRRH |
3868 | } else { |
3869 | add_trampoline_func(m, NULL, rec); | |
9674b2fa | 3870 | } |
cbad0fb2 MR |
3871 | if (rec->flags & FTRACE_FL_CALL_OPS_EN) { |
3872 | ops = ftrace_find_unique_ops(rec); | |
3873 | if (ops) { | |
3874 | seq_printf(m, "\tops: %pS (%pS)", | |
3875 | ops, ops->func); | |
3876 | } else { | |
3877 | seq_puts(m, "\tops: ERROR!"); | |
3878 | } | |
3879 | } | |
763e34e7 SRV |
3880 | if (rec->flags & FTRACE_FL_DIRECT) { |
3881 | unsigned long direct; | |
3882 | ||
ff205766 | 3883 | direct = ftrace_find_rec_direct(rec->ip); |
763e34e7 SRV |
3884 | if (direct) |
3885 | seq_printf(m, "\n\tdirect-->%pS", (void *)direct); | |
3886 | } | |
026bb845 | 3887 | } |
9674b2fa | 3888 | |
fa6f0cc7 | 3889 | seq_putc(m, '\n'); |
5072c59f SR |
3890 | |
3891 | return 0; | |
3892 | } | |
3893 | ||
88e9d34c | 3894 | static const struct seq_operations show_ftrace_seq_ops = { |
5072c59f SR |
3895 | .start = t_start, |
3896 | .next = t_next, | |
3897 | .stop = t_stop, | |
3898 | .show = t_show, | |
3899 | }; | |
3900 | ||
e309b41d | 3901 | static int |
5072c59f SR |
3902 | ftrace_avail_open(struct inode *inode, struct file *file) |
3903 | { | |
3904 | struct ftrace_iterator *iter; | |
17911ff3 SRV |
3905 | int ret; |
3906 | ||
3907 | ret = security_locked_down(LOCKDOWN_TRACEFS); | |
3908 | if (ret) | |
3909 | return ret; | |
5072c59f | 3910 | |
4eebcc81 SR |
3911 | if (unlikely(ftrace_disabled)) |
3912 | return -ENODEV; | |
3913 | ||
50e18b94 | 3914 | iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); |
c1bc5919 SRV |
3915 | if (!iter) |
3916 | return -ENOMEM; | |
5072c59f | 3917 | |
c1bc5919 SRV |
3918 | iter->pg = ftrace_pages_start; |
3919 | iter->ops = &global_ops; | |
3920 | ||
3921 | return 0; | |
5072c59f SR |
3922 | } |
3923 | ||
647bcd03 SR |
3924 | static int |
3925 | ftrace_enabled_open(struct inode *inode, struct file *file) | |
3926 | { | |
3927 | struct ftrace_iterator *iter; | |
647bcd03 | 3928 | |
17911ff3 SRV |
3929 | /* |
3930 | * This shows us what functions are currently being | |
3931 | * traced and by what. Not sure if we want lockdown | |
3932 | * to hide such critical information for an admin. | |
3933 | * Although, perhaps it can show information we don't | |
3934 | * want people to see, but if something is tracing | |
3935 | * something, we probably want to know about it. | |
3936 | */ | |
3937 | ||
50e18b94 | 3938 | iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); |
c1bc5919 SRV |
3939 | if (!iter) |
3940 | return -ENOMEM; | |
647bcd03 | 3941 | |
c1bc5919 SRV |
3942 | iter->pg = ftrace_pages_start; |
3943 | iter->flags = FTRACE_ITER_ENABLED; | |
3944 | iter->ops = &global_ops; | |
3945 | ||
3946 | return 0; | |
647bcd03 SR |
3947 | } |
3948 | ||
e11b521a SRG |
3949 | static int |
3950 | ftrace_touched_open(struct inode *inode, struct file *file) | |
3951 | { | |
3952 | struct ftrace_iterator *iter; | |
3953 | ||
3954 | /* | |
3955 | * This shows us what functions have ever been enabled | |
3956 | * (traced, direct, patched, etc). Not sure if we want lockdown | |
3957 | * to hide such critical information for an admin. | |
3958 | * Although, perhaps it can show information we don't | |
3959 | * want people to see, but if something had traced | |
3960 | * something, we probably want to know about it. | |
3961 | */ | |
3962 | ||
3963 | iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); | |
3964 | if (!iter) | |
3965 | return -ENOMEM; | |
3966 | ||
3967 | iter->pg = ftrace_pages_start; | |
3968 | iter->flags = FTRACE_ITER_TOUCHED; | |
3969 | iter->ops = &global_ops; | |
3970 | ||
3971 | return 0; | |
3972 | } | |
3973 | ||
83f74441 JO |
3974 | static int |
3975 | ftrace_avail_addrs_open(struct inode *inode, struct file *file) | |
3976 | { | |
3977 | struct ftrace_iterator *iter; | |
3978 | int ret; | |
3979 | ||
3980 | ret = security_locked_down(LOCKDOWN_TRACEFS); | |
3981 | if (ret) | |
3982 | return ret; | |
3983 | ||
3984 | if (unlikely(ftrace_disabled)) | |
3985 | return -ENODEV; | |
3986 | ||
3987 | iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); | |
3988 | if (!iter) | |
3989 | return -ENOMEM; | |
3990 | ||
3991 | iter->pg = ftrace_pages_start; | |
3992 | iter->flags = FTRACE_ITER_ADDRS; | |
3993 | iter->ops = &global_ops; | |
3994 | ||
3995 | return 0; | |
3996 | } | |
3997 | ||
fc13cb0c SR |
3998 | /** |
3999 | * ftrace_regex_open - initialize function tracer filter files | |
4000 | * @ops: The ftrace_ops that hold the hash filters | |
4001 | * @flag: The type of filter to process | |
4002 | * @inode: The inode, usually passed in to your open routine | |
4003 | * @file: The file, usually passed in to your open routine | |
4004 | * | |
4005 | * ftrace_regex_open() initializes the filter files for the | |
4006 | * @ops. Depending on @flag it may process the filter hash or | |
4007 | * the notrace hash of @ops. With this called from the open | |
4008 | * routine, you can use ftrace_filter_write() for the write | |
4009 | * routine if @flag has FTRACE_ITER_FILTER set, or | |
4010 | * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set. | |
098c879e | 4011 | * tracing_lseek() should be used as the lseek routine, and |
fc13cb0c | 4012 | * release must call ftrace_regex_release(). |
d1530413 RD |
4013 | * |
4014 | * Returns: 0 on success or a negative errno value on failure | |
fc13cb0c SR |
4015 | */ |
4016 | int | |
f45948e8 | 4017 | ftrace_regex_open(struct ftrace_ops *ops, int flag, |
1cf41dd7 | 4018 | struct inode *inode, struct file *file) |
5072c59f SR |
4019 | { |
4020 | struct ftrace_iterator *iter; | |
f45948e8 | 4021 | struct ftrace_hash *hash; |
673feb9d SRV |
4022 | struct list_head *mod_head; |
4023 | struct trace_array *tr = ops->private; | |
9ef16693 | 4024 | int ret = -ENOMEM; |
5072c59f | 4025 | |
f04f24fb MH |
4026 | ftrace_ops_init(ops); |
4027 | ||
4eebcc81 SR |
4028 | if (unlikely(ftrace_disabled)) |
4029 | return -ENODEV; | |
4030 | ||
8530dec6 | 4031 | if (tracing_check_open_get_tr(tr)) |
9ef16693 SRV |
4032 | return -ENODEV; |
4033 | ||
5072c59f SR |
4034 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
4035 | if (!iter) | |
9ef16693 | 4036 | goto out; |
5072c59f | 4037 | |
9ef16693 SRV |
4038 | if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) |
4039 | goto out; | |
689fd8b6 | 4040 | |
3f2367ba MH |
4041 | iter->ops = ops; |
4042 | iter->flags = flag; | |
5985ea8b | 4043 | iter->tr = tr; |
3f2367ba | 4044 | |
33b7f99c | 4045 | mutex_lock(&ops->func_hash->regex_lock); |
3f2367ba | 4046 | |
673feb9d | 4047 | if (flag & FTRACE_ITER_NOTRACE) { |
33b7f99c | 4048 | hash = ops->func_hash->notrace_hash; |
5985ea8b | 4049 | mod_head = tr ? &tr->mod_notrace : NULL; |
673feb9d | 4050 | } else { |
33b7f99c | 4051 | hash = ops->func_hash->filter_hash; |
5985ea8b | 4052 | mod_head = tr ? &tr->mod_trace : NULL; |
673feb9d | 4053 | } |
f45948e8 | 4054 | |
5985ea8b SRV |
4055 | iter->mod_list = mod_head; |
4056 | ||
33dc9b12 | 4057 | if (file->f_mode & FMODE_WRITE) { |
ef2fbe16 NK |
4058 | const int size_bits = FTRACE_HASH_DEFAULT_BITS; |
4059 | ||
673feb9d | 4060 | if (file->f_flags & O_TRUNC) { |
ef2fbe16 | 4061 | iter->hash = alloc_ftrace_hash(size_bits); |
673feb9d SRV |
4062 | clear_ftrace_mod_list(mod_head); |
4063 | } else { | |
ef2fbe16 | 4064 | iter->hash = alloc_and_copy_ftrace_hash(size_bits, hash); |
673feb9d | 4065 | } |
ef2fbe16 | 4066 | |
33dc9b12 SR |
4067 | if (!iter->hash) { |
4068 | trace_parser_put(&iter->parser); | |
3f2367ba | 4069 | goto out_unlock; |
33dc9b12 | 4070 | } |
c20489da SRV |
4071 | } else |
4072 | iter->hash = hash; | |
1cf41dd7 | 4073 | |
9ef16693 SRV |
4074 | ret = 0; |
4075 | ||
5072c59f SR |
4076 | if (file->f_mode & FMODE_READ) { |
4077 | iter->pg = ftrace_pages_start; | |
5072c59f SR |
4078 | |
4079 | ret = seq_open(file, &show_ftrace_seq_ops); | |
4080 | if (!ret) { | |
4081 | struct seq_file *m = file->private_data; | |
4082 | m->private = iter; | |
79fe249c | 4083 | } else { |
33dc9b12 SR |
4084 | /* Failed */ |
4085 | free_ftrace_hash(iter->hash); | |
79fe249c | 4086 | trace_parser_put(&iter->parser); |
79fe249c | 4087 | } |
5072c59f SR |
4088 | } else |
4089 | file->private_data = iter; | |
3f2367ba MH |
4090 | |
4091 | out_unlock: | |
33b7f99c | 4092 | mutex_unlock(&ops->func_hash->regex_lock); |
5072c59f | 4093 | |
9ef16693 SRV |
4094 | out: |
4095 | if (ret) { | |
4096 | kfree(iter); | |
4097 | if (tr) | |
4098 | trace_array_put(tr); | |
4099 | } | |
4100 | ||
5072c59f SR |
4101 | return ret; |
4102 | } | |
4103 | ||
41c52c0d SR |
4104 | static int |
4105 | ftrace_filter_open(struct inode *inode, struct file *file) | |
4106 | { | |
e3b3e2e8 SRRH |
4107 | struct ftrace_ops *ops = inode->i_private; |
4108 | ||
17911ff3 | 4109 | /* Checks for tracefs lockdown */ |
e3b3e2e8 | 4110 | return ftrace_regex_open(ops, |
eee8ded1 | 4111 | FTRACE_ITER_FILTER | FTRACE_ITER_DO_PROBES, |
69a3083c | 4112 | inode, file); |
41c52c0d SR |
4113 | } |
4114 | ||
4115 | static int | |
4116 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
4117 | { | |
e3b3e2e8 SRRH |
4118 | struct ftrace_ops *ops = inode->i_private; |
4119 | ||
17911ff3 | 4120 | /* Checks for tracefs lockdown */ |
e3b3e2e8 | 4121 | return ftrace_regex_open(ops, FTRACE_ITER_NOTRACE, |
1cf41dd7 | 4122 | inode, file); |
41c52c0d SR |
4123 | } |
4124 | ||
3ba00929 DS |
4125 | /* Type for quick search ftrace basic regexes (globs) from filter_parse_regex */ |
4126 | struct ftrace_glob { | |
4127 | char *search; | |
4128 | unsigned len; | |
4129 | int type; | |
4130 | }; | |
4131 | ||
7132e2d6 TJB |
4132 | /* |
4133 | * If symbols in an architecture don't correspond exactly to the user-visible | |
4134 | * name of what they represent, it is possible to define this function to | |
4135 | * perform the necessary adjustments. | |
4136 | */ | |
4137 | char * __weak arch_ftrace_match_adjust(char *str, const char *search) | |
4138 | { | |
4139 | return str; | |
4140 | } | |
4141 | ||
3ba00929 | 4142 | static int ftrace_match(char *str, struct ftrace_glob *g) |
9f4801e3 | 4143 | { |
9f4801e3 | 4144 | int matched = 0; |
751e9983 | 4145 | int slen; |
9f4801e3 | 4146 | |
7132e2d6 TJB |
4147 | str = arch_ftrace_match_adjust(str, g->search); |
4148 | ||
3ba00929 | 4149 | switch (g->type) { |
9f4801e3 | 4150 | case MATCH_FULL: |
3ba00929 | 4151 | if (strcmp(str, g->search) == 0) |
9f4801e3 SR |
4152 | matched = 1; |
4153 | break; | |
4154 | case MATCH_FRONT_ONLY: | |
3ba00929 | 4155 | if (strncmp(str, g->search, g->len) == 0) |
9f4801e3 SR |
4156 | matched = 1; |
4157 | break; | |
4158 | case MATCH_MIDDLE_ONLY: | |
3ba00929 | 4159 | if (strstr(str, g->search)) |
9f4801e3 SR |
4160 | matched = 1; |
4161 | break; | |
4162 | case MATCH_END_ONLY: | |
751e9983 | 4163 | slen = strlen(str); |
3ba00929 DS |
4164 | if (slen >= g->len && |
4165 | memcmp(str + slen - g->len, g->search, g->len) == 0) | |
9f4801e3 SR |
4166 | matched = 1; |
4167 | break; | |
60f1d5e3 MH |
4168 | case MATCH_GLOB: |
4169 | if (glob_match(g->search, str)) | |
4170 | matched = 1; | |
4171 | break; | |
9f4801e3 SR |
4172 | } |
4173 | ||
4174 | return matched; | |
4175 | } | |
4176 | ||
b448c4e3 | 4177 | static int |
f0a3b154 | 4178 | enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int clear_filter) |
996e87be | 4179 | { |
b448c4e3 | 4180 | struct ftrace_func_entry *entry; |
b448c4e3 SR |
4181 | int ret = 0; |
4182 | ||
1cf41dd7 | 4183 | entry = ftrace_lookup_ip(hash, rec->ip); |
f0a3b154 | 4184 | if (clear_filter) { |
1cf41dd7 SR |
4185 | /* Do nothing if it doesn't exist */ |
4186 | if (!entry) | |
4187 | return 0; | |
b448c4e3 | 4188 | |
33dc9b12 | 4189 | free_hash_entry(hash, entry); |
1cf41dd7 SR |
4190 | } else { |
4191 | /* Do nothing if it exists */ | |
4192 | if (entry) | |
4193 | return 0; | |
d05cb470 SRG |
4194 | if (add_hash_entry(hash, rec->ip) == NULL) |
4195 | ret = -ENOMEM; | |
b448c4e3 SR |
4196 | } |
4197 | return ret; | |
996e87be SR |
4198 | } |
4199 | ||
f79b3f33 SRV |
4200 | static int |
4201 | add_rec_by_index(struct ftrace_hash *hash, struct ftrace_glob *func_g, | |
4202 | int clear_filter) | |
4203 | { | |
4204 | long index = simple_strtoul(func_g->search, NULL, 0); | |
4205 | struct ftrace_page *pg; | |
4206 | struct dyn_ftrace *rec; | |
4207 | ||
4208 | /* The index starts at 1 */ | |
4209 | if (--index < 0) | |
4210 | return 0; | |
4211 | ||
4212 | do_for_each_ftrace_rec(pg, rec) { | |
4213 | if (pg->index <= index) { | |
4214 | index -= pg->index; | |
4215 | /* this is a double loop, break goes to the next page */ | |
4216 | break; | |
4217 | } | |
4218 | rec = &pg->records[index]; | |
4219 | enter_record(hash, rec, clear_filter); | |
4220 | return 1; | |
4221 | } while_for_each_ftrace_rec(); | |
4222 | return 0; | |
4223 | } | |
4224 | ||
b39181f7 SRG |
4225 | #ifdef FTRACE_MCOUNT_MAX_OFFSET |
4226 | static int lookup_ip(unsigned long ip, char **modname, char *str) | |
4227 | { | |
4228 | unsigned long offset; | |
4229 | ||
4230 | kallsyms_lookup(ip, NULL, &offset, modname, str); | |
4231 | if (offset > FTRACE_MCOUNT_MAX_OFFSET) | |
4232 | return -1; | |
4233 | return 0; | |
4234 | } | |
4235 | #else | |
4236 | static int lookup_ip(unsigned long ip, char **modname, char *str) | |
4237 | { | |
4238 | kallsyms_lookup(ip, NULL, NULL, modname, str); | |
4239 | return 0; | |
4240 | } | |
4241 | #endif | |
4242 | ||
64e7c440 | 4243 | static int |
0b507e1e DS |
4244 | ftrace_match_record(struct dyn_ftrace *rec, struct ftrace_glob *func_g, |
4245 | struct ftrace_glob *mod_g, int exclude_mod) | |
64e7c440 SR |
4246 | { |
4247 | char str[KSYM_SYMBOL_LEN]; | |
b9df92d2 SR |
4248 | char *modname; |
4249 | ||
b39181f7 SRG |
4250 | if (lookup_ip(rec->ip, &modname, str)) { |
4251 | /* This should only happen when a rec is disabled */ | |
4252 | WARN_ON_ONCE(system_state == SYSTEM_RUNNING && | |
4253 | !(rec->flags & FTRACE_FL_DISABLED)); | |
4254 | return 0; | |
4255 | } | |
b9df92d2 | 4256 | |
0b507e1e DS |
4257 | if (mod_g) { |
4258 | int mod_matches = (modname) ? ftrace_match(modname, mod_g) : 0; | |
4259 | ||
4260 | /* blank module name to match all modules */ | |
4261 | if (!mod_g->len) { | |
4262 | /* blank module globbing: modname xor exclude_mod */ | |
77c0edde | 4263 | if (!exclude_mod != !modname) |
0b507e1e DS |
4264 | goto func_match; |
4265 | return 0; | |
4266 | } | |
4267 | ||
77c0edde SRV |
4268 | /* |
4269 | * exclude_mod is set to trace everything but the given | |
4270 | * module. If it is set and the module matches, then | |
4271 | * return 0. If it is not set, and the module doesn't match | |
4272 | * also return 0. Otherwise, check the function to see if | |
4273 | * that matches. | |
4274 | */ | |
4275 | if (!mod_matches == !exclude_mod) | |
b9df92d2 | 4276 | return 0; |
0b507e1e | 4277 | func_match: |
b9df92d2 | 4278 | /* blank search means to match all funcs in the mod */ |
3ba00929 | 4279 | if (!func_g->len) |
b9df92d2 SR |
4280 | return 1; |
4281 | } | |
64e7c440 | 4282 | |
3ba00929 | 4283 | return ftrace_match(str, func_g); |
64e7c440 SR |
4284 | } |
4285 | ||
1cf41dd7 | 4286 | static int |
3ba00929 | 4287 | match_records(struct ftrace_hash *hash, char *func, int len, char *mod) |
9f4801e3 | 4288 | { |
9f4801e3 SR |
4289 | struct ftrace_page *pg; |
4290 | struct dyn_ftrace *rec; | |
3ba00929 | 4291 | struct ftrace_glob func_g = { .type = MATCH_FULL }; |
0b507e1e DS |
4292 | struct ftrace_glob mod_g = { .type = MATCH_FULL }; |
4293 | struct ftrace_glob *mod_match = (mod) ? &mod_g : NULL; | |
4294 | int exclude_mod = 0; | |
311d16da | 4295 | int found = 0; |
b448c4e3 | 4296 | int ret; |
2e028c4f | 4297 | int clear_filter = 0; |
9f4801e3 | 4298 | |
0b507e1e | 4299 | if (func) { |
3ba00929 DS |
4300 | func_g.type = filter_parse_regex(func, len, &func_g.search, |
4301 | &clear_filter); | |
4302 | func_g.len = strlen(func_g.search); | |
b9df92d2 | 4303 | } |
9f4801e3 | 4304 | |
0b507e1e DS |
4305 | if (mod) { |
4306 | mod_g.type = filter_parse_regex(mod, strlen(mod), | |
4307 | &mod_g.search, &exclude_mod); | |
4308 | mod_g.len = strlen(mod_g.search); | |
b9df92d2 | 4309 | } |
9f4801e3 | 4310 | |
52baf119 | 4311 | mutex_lock(&ftrace_lock); |
265c831c | 4312 | |
b9df92d2 SR |
4313 | if (unlikely(ftrace_disabled)) |
4314 | goto out_unlock; | |
9f4801e3 | 4315 | |
f79b3f33 SRV |
4316 | if (func_g.type == MATCH_INDEX) { |
4317 | found = add_rec_by_index(hash, &func_g, clear_filter); | |
4318 | goto out_unlock; | |
4319 | } | |
4320 | ||
265c831c | 4321 | do_for_each_ftrace_rec(pg, rec) { |
546fece4 SRRH |
4322 | |
4323 | if (rec->flags & FTRACE_FL_DISABLED) | |
4324 | continue; | |
4325 | ||
0b507e1e | 4326 | if (ftrace_match_record(rec, &func_g, mod_match, exclude_mod)) { |
f0a3b154 | 4327 | ret = enter_record(hash, rec, clear_filter); |
b448c4e3 SR |
4328 | if (ret < 0) { |
4329 | found = ret; | |
4330 | goto out_unlock; | |
4331 | } | |
311d16da | 4332 | found = 1; |
265c831c | 4333 | } |
d0b24b4e | 4334 | cond_resched(); |
265c831c | 4335 | } while_for_each_ftrace_rec(); |
b9df92d2 | 4336 | out_unlock: |
52baf119 | 4337 | mutex_unlock(&ftrace_lock); |
311d16da LZ |
4338 | |
4339 | return found; | |
5072c59f SR |
4340 | } |
4341 | ||
64e7c440 | 4342 | static int |
1cf41dd7 | 4343 | ftrace_match_records(struct ftrace_hash *hash, char *buff, int len) |
64e7c440 | 4344 | { |
f0a3b154 | 4345 | return match_records(hash, buff, len, NULL); |
64e7c440 SR |
4346 | } |
4347 | ||
e16b35dd SRV |
4348 | static void ftrace_ops_update_code(struct ftrace_ops *ops, |
4349 | struct ftrace_ops_hash *old_hash) | |
4350 | { | |
4351 | struct ftrace_ops *op; | |
4352 | ||
4353 | if (!ftrace_enabled) | |
4354 | return; | |
4355 | ||
4356 | if (ops->flags & FTRACE_OPS_FL_ENABLED) { | |
4357 | ftrace_run_modify_code(ops, FTRACE_UPDATE_CALLS, old_hash); | |
4358 | return; | |
4359 | } | |
4360 | ||
4361 | /* | |
4362 | * If this is the shared global_ops filter, then we need to | |
4363 | * check if there is another ops that shares it, is enabled. | |
4364 | * If so, we still need to run the modify code. | |
4365 | */ | |
4366 | if (ops->func_hash != &global_ops.local_hash) | |
4367 | return; | |
4368 | ||
4369 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
4370 | if (op->func_hash == &global_ops.local_hash && | |
4371 | op->flags & FTRACE_OPS_FL_ENABLED) { | |
4372 | ftrace_run_modify_code(op, FTRACE_UPDATE_CALLS, old_hash); | |
4373 | /* Only need to do this once */ | |
4374 | return; | |
4375 | } | |
4376 | } while_for_each_ftrace_op(op); | |
4377 | } | |
4378 | ||
4379 | static int ftrace_hash_move_and_update_ops(struct ftrace_ops *ops, | |
4380 | struct ftrace_hash **orig_hash, | |
4381 | struct ftrace_hash *hash, | |
4382 | int enable) | |
4383 | { | |
4384 | struct ftrace_ops_hash old_hash_ops; | |
4385 | struct ftrace_hash *old_hash; | |
4386 | int ret; | |
4387 | ||
4388 | old_hash = *orig_hash; | |
4389 | old_hash_ops.filter_hash = ops->func_hash->filter_hash; | |
4390 | old_hash_ops.notrace_hash = ops->func_hash->notrace_hash; | |
4391 | ret = ftrace_hash_move(ops, enable, orig_hash, hash); | |
4392 | if (!ret) { | |
4393 | ftrace_ops_update_code(ops, &old_hash_ops); | |
4394 | free_ftrace_hash_rcu(old_hash); | |
4395 | } | |
4396 | return ret; | |
4397 | } | |
64e7c440 | 4398 | |
673feb9d SRV |
4399 | static bool module_exists(const char *module) |
4400 | { | |
4401 | /* All modules have the symbol __this_module */ | |
0f5e5a3a | 4402 | static const char this_mod[] = "__this_module"; |
419e9fe5 | 4403 | char modname[MAX_PARAM_PREFIX_LEN + sizeof(this_mod) + 2]; |
673feb9d SRV |
4404 | unsigned long val; |
4405 | int n; | |
4406 | ||
419e9fe5 | 4407 | n = snprintf(modname, sizeof(modname), "%s:%s", module, this_mod); |
673feb9d | 4408 | |
419e9fe5 | 4409 | if (n > sizeof(modname) - 1) |
673feb9d SRV |
4410 | return false; |
4411 | ||
4412 | val = module_kallsyms_lookup_name(modname); | |
4413 | return val != 0; | |
4414 | } | |
4415 | ||
4416 | static int cache_mod(struct trace_array *tr, | |
4417 | const char *func, char *module, int enable) | |
4418 | { | |
4419 | struct ftrace_mod_load *ftrace_mod, *n; | |
4420 | struct list_head *head = enable ? &tr->mod_trace : &tr->mod_notrace; | |
4421 | int ret; | |
4422 | ||
4423 | mutex_lock(&ftrace_lock); | |
4424 | ||
4425 | /* We do not cache inverse filters */ | |
4426 | if (func[0] == '!') { | |
4427 | func++; | |
4428 | ret = -EINVAL; | |
4429 | ||
4430 | /* Look to remove this hash */ | |
4431 | list_for_each_entry_safe(ftrace_mod, n, head, list) { | |
4432 | if (strcmp(ftrace_mod->module, module) != 0) | |
4433 | continue; | |
4434 | ||
4435 | /* no func matches all */ | |
44925dff | 4436 | if (strcmp(func, "*") == 0 || |
673feb9d SRV |
4437 | (ftrace_mod->func && |
4438 | strcmp(ftrace_mod->func, func) == 0)) { | |
4439 | ret = 0; | |
4440 | free_ftrace_mod(ftrace_mod); | |
4441 | continue; | |
4442 | } | |
4443 | } | |
4444 | goto out; | |
4445 | } | |
4446 | ||
4447 | ret = -EINVAL; | |
4448 | /* We only care about modules that have not been loaded yet */ | |
4449 | if (module_exists(module)) | |
4450 | goto out; | |
4451 | ||
4452 | /* Save this string off, and execute it when the module is loaded */ | |
4453 | ret = ftrace_add_mod(tr, func, module, enable); | |
4454 | out: | |
4455 | mutex_unlock(&ftrace_lock); | |
4456 | ||
4457 | return ret; | |
4458 | } | |
4459 | ||
d7fbf8df SRV |
4460 | static int |
4461 | ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, | |
4462 | int reset, int enable); | |
4463 | ||
69449bbd | 4464 | #ifdef CONFIG_MODULES |
d7fbf8df SRV |
4465 | static void process_mod_list(struct list_head *head, struct ftrace_ops *ops, |
4466 | char *mod, bool enable) | |
4467 | { | |
4468 | struct ftrace_mod_load *ftrace_mod, *n; | |
4469 | struct ftrace_hash **orig_hash, *new_hash; | |
4470 | LIST_HEAD(process_mods); | |
4471 | char *func; | |
d7fbf8df SRV |
4472 | |
4473 | mutex_lock(&ops->func_hash->regex_lock); | |
4474 | ||
4475 | if (enable) | |
4476 | orig_hash = &ops->func_hash->filter_hash; | |
4477 | else | |
4478 | orig_hash = &ops->func_hash->notrace_hash; | |
4479 | ||
4480 | new_hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, | |
4481 | *orig_hash); | |
4482 | if (!new_hash) | |
3b58a3c7 | 4483 | goto out; /* warn? */ |
d7fbf8df SRV |
4484 | |
4485 | mutex_lock(&ftrace_lock); | |
4486 | ||
4487 | list_for_each_entry_safe(ftrace_mod, n, head, list) { | |
4488 | ||
4489 | if (strcmp(ftrace_mod->module, mod) != 0) | |
4490 | continue; | |
4491 | ||
4492 | if (ftrace_mod->func) | |
4493 | func = kstrdup(ftrace_mod->func, GFP_KERNEL); | |
4494 | else | |
4495 | func = kstrdup("*", GFP_KERNEL); | |
4496 | ||
4497 | if (!func) /* warn? */ | |
4498 | continue; | |
4499 | ||
3ecda644 | 4500 | list_move(&ftrace_mod->list, &process_mods); |
d7fbf8df SRV |
4501 | |
4502 | /* Use the newly allocated func, as it may be "*" */ | |
4503 | kfree(ftrace_mod->func); | |
4504 | ftrace_mod->func = func; | |
4505 | } | |
4506 | ||
4507 | mutex_unlock(&ftrace_lock); | |
4508 | ||
4509 | list_for_each_entry_safe(ftrace_mod, n, &process_mods, list) { | |
4510 | ||
4511 | func = ftrace_mod->func; | |
4512 | ||
4513 | /* Grabs ftrace_lock, which is why we have this extra step */ | |
4514 | match_records(new_hash, func, strlen(func), mod); | |
4515 | free_ftrace_mod(ftrace_mod); | |
4516 | } | |
4517 | ||
8c08f0d5 SRV |
4518 | if (enable && list_empty(head)) |
4519 | new_hash->flags &= ~FTRACE_HASH_FL_MOD; | |
4520 | ||
d7fbf8df SRV |
4521 | mutex_lock(&ftrace_lock); |
4522 | ||
045e269c | 4523 | ftrace_hash_move_and_update_ops(ops, orig_hash, |
d7fbf8df SRV |
4524 | new_hash, enable); |
4525 | mutex_unlock(&ftrace_lock); | |
4526 | ||
3b58a3c7 | 4527 | out: |
d7fbf8df SRV |
4528 | mutex_unlock(&ops->func_hash->regex_lock); |
4529 | ||
4530 | free_ftrace_hash(new_hash); | |
4531 | } | |
4532 | ||
4533 | static void process_cached_mods(const char *mod_name) | |
4534 | { | |
4535 | struct trace_array *tr; | |
4536 | char *mod; | |
4537 | ||
4538 | mod = kstrdup(mod_name, GFP_KERNEL); | |
4539 | if (!mod) | |
4540 | return; | |
4541 | ||
4542 | mutex_lock(&trace_types_lock); | |
4543 | list_for_each_entry(tr, &ftrace_trace_arrays, list) { | |
4544 | if (!list_empty(&tr->mod_trace)) | |
4545 | process_mod_list(&tr->mod_trace, tr->ops, mod, true); | |
4546 | if (!list_empty(&tr->mod_notrace)) | |
4547 | process_mod_list(&tr->mod_notrace, tr->ops, mod, false); | |
4548 | } | |
4549 | mutex_unlock(&trace_types_lock); | |
4550 | ||
4551 | kfree(mod); | |
4552 | } | |
69449bbd | 4553 | #endif |
d7fbf8df | 4554 | |
f6180773 SR |
4555 | /* |
4556 | * We register the module command as a template to show others how | |
4557 | * to register the a command as well. | |
4558 | */ | |
4559 | ||
4560 | static int | |
04ec7bb6 | 4561 | ftrace_mod_callback(struct trace_array *tr, struct ftrace_hash *hash, |
673feb9d | 4562 | char *func_orig, char *cmd, char *module, int enable) |
f6180773 | 4563 | { |
673feb9d | 4564 | char *func; |
5e3949f0 | 4565 | int ret; |
f6180773 | 4566 | |
673feb9d SRV |
4567 | /* match_records() modifies func, and we need the original */ |
4568 | func = kstrdup(func_orig, GFP_KERNEL); | |
4569 | if (!func) | |
4570 | return -ENOMEM; | |
4571 | ||
f6180773 SR |
4572 | /* |
4573 | * cmd == 'mod' because we only registered this func | |
4574 | * for the 'mod' ftrace_func_command. | |
4575 | * But if you register one func with multiple commands, | |
4576 | * you can tell which command was used by the cmd | |
4577 | * parameter. | |
4578 | */ | |
f0a3b154 | 4579 | ret = match_records(hash, func, strlen(func), module); |
673feb9d SRV |
4580 | kfree(func); |
4581 | ||
b448c4e3 | 4582 | if (!ret) |
673feb9d | 4583 | return cache_mod(tr, func_orig, module, enable); |
b448c4e3 SR |
4584 | if (ret < 0) |
4585 | return ret; | |
b448c4e3 | 4586 | return 0; |
f6180773 SR |
4587 | } |
4588 | ||
4589 | static struct ftrace_func_command ftrace_mod_cmd = { | |
4590 | .name = "mod", | |
4591 | .func = ftrace_mod_callback, | |
4592 | }; | |
4593 | ||
4594 | static int __init ftrace_mod_cmd_init(void) | |
4595 | { | |
4596 | return register_ftrace_command(&ftrace_mod_cmd); | |
4597 | } | |
6f415672 | 4598 | core_initcall(ftrace_mod_cmd_init); |
f6180773 | 4599 | |
2f5f6ad9 | 4600 | static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip, |
d19ad077 | 4601 | struct ftrace_ops *op, struct ftrace_regs *fregs) |
59df055f | 4602 | { |
eee8ded1 | 4603 | struct ftrace_probe_ops *probe_ops; |
7b60f3d8 | 4604 | struct ftrace_func_probe *probe; |
59df055f | 4605 | |
7b60f3d8 SRV |
4606 | probe = container_of(op, struct ftrace_func_probe, ops); |
4607 | probe_ops = probe->probe_ops; | |
59df055f SR |
4608 | |
4609 | /* | |
4610 | * Disable preemption for these calls to prevent a RCU grace | |
4611 | * period. This syncs the hash iteration and freeing of items | |
4612 | * on the hash. rcu_read_lock is too dangerous here. | |
4613 | */ | |
5168ae50 | 4614 | preempt_disable_notrace(); |
6e444319 | 4615 | probe_ops->func(ip, parent_ip, probe->tr, probe_ops, probe->data); |
5168ae50 | 4616 | preempt_enable_notrace(); |
59df055f SR |
4617 | } |
4618 | ||
41794f19 SRV |
4619 | struct ftrace_func_map { |
4620 | struct ftrace_func_entry entry; | |
4621 | void *data; | |
59df055f SR |
4622 | }; |
4623 | ||
41794f19 SRV |
4624 | struct ftrace_func_mapper { |
4625 | struct ftrace_hash hash; | |
4626 | }; | |
59df055f | 4627 | |
41794f19 SRV |
4628 | /** |
4629 | * allocate_ftrace_func_mapper - allocate a new ftrace_func_mapper | |
4630 | * | |
d1530413 | 4631 | * Returns: a ftrace_func_mapper descriptor that can be used to map ips to data. |
41794f19 SRV |
4632 | */ |
4633 | struct ftrace_func_mapper *allocate_ftrace_func_mapper(void) | |
59df055f | 4634 | { |
41794f19 | 4635 | struct ftrace_hash *hash; |
59df055f | 4636 | |
41794f19 SRV |
4637 | /* |
4638 | * The mapper is simply a ftrace_hash, but since the entries | |
4639 | * in the hash are not ftrace_func_entry type, we define it | |
4640 | * as a separate structure. | |
4641 | */ | |
4642 | hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS); | |
4643 | return (struct ftrace_func_mapper *)hash; | |
4644 | } | |
59df055f | 4645 | |
41794f19 SRV |
4646 | /** |
4647 | * ftrace_func_mapper_find_ip - Find some data mapped to an ip | |
4648 | * @mapper: The mapper that has the ip maps | |
4649 | * @ip: the instruction pointer to find the data for | |
4650 | * | |
d1530413 | 4651 | * Returns: the data mapped to @ip if found otherwise NULL. The return |
41794f19 SRV |
4652 | * is actually the address of the mapper data pointer. The address is |
4653 | * returned for use cases where the data is no bigger than a long, and | |
4654 | * the user can use the data pointer as its data instead of having to | |
4655 | * allocate more memory for the reference. | |
4656 | */ | |
4657 | void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper, | |
4658 | unsigned long ip) | |
4659 | { | |
4660 | struct ftrace_func_entry *entry; | |
4661 | struct ftrace_func_map *map; | |
59df055f | 4662 | |
41794f19 SRV |
4663 | entry = ftrace_lookup_ip(&mapper->hash, ip); |
4664 | if (!entry) | |
4665 | return NULL; | |
b848914c | 4666 | |
41794f19 SRV |
4667 | map = (struct ftrace_func_map *)entry; |
4668 | return &map->data; | |
59df055f SR |
4669 | } |
4670 | ||
41794f19 SRV |
4671 | /** |
4672 | * ftrace_func_mapper_add_ip - Map some data to an ip | |
4673 | * @mapper: The mapper that has the ip maps | |
4674 | * @ip: The instruction pointer address to map @data to | |
4675 | * @data: The data to map to @ip | |
4676 | * | |
d1530413 | 4677 | * Returns: 0 on success otherwise an error. |
41794f19 SRV |
4678 | */ |
4679 | int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper, | |
4680 | unsigned long ip, void *data) | |
59df055f | 4681 | { |
41794f19 SRV |
4682 | struct ftrace_func_entry *entry; |
4683 | struct ftrace_func_map *map; | |
59df055f | 4684 | |
41794f19 SRV |
4685 | entry = ftrace_lookup_ip(&mapper->hash, ip); |
4686 | if (entry) | |
4687 | return -EBUSY; | |
59df055f | 4688 | |
41794f19 SRV |
4689 | map = kmalloc(sizeof(*map), GFP_KERNEL); |
4690 | if (!map) | |
4691 | return -ENOMEM; | |
59df055f | 4692 | |
41794f19 SRV |
4693 | map->entry.ip = ip; |
4694 | map->data = data; | |
b848914c | 4695 | |
41794f19 | 4696 | __add_hash_entry(&mapper->hash, &map->entry); |
59df055f | 4697 | |
41794f19 SRV |
4698 | return 0; |
4699 | } | |
59df055f | 4700 | |
41794f19 SRV |
4701 | /** |
4702 | * ftrace_func_mapper_remove_ip - Remove an ip from the mapping | |
4703 | * @mapper: The mapper that has the ip maps | |
4704 | * @ip: The instruction pointer address to remove the data from | |
4705 | * | |
d1530413 | 4706 | * Returns: the data if it is found, otherwise NULL. |
7d54c15c | 4707 | * Note, if the data pointer is used as the data itself, (see |
41794f19 SRV |
4708 | * ftrace_func_mapper_find_ip(), then the return value may be meaningless, |
4709 | * if the data pointer was set to zero. | |
4710 | */ | |
4711 | void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper, | |
4712 | unsigned long ip) | |
59df055f | 4713 | { |
41794f19 SRV |
4714 | struct ftrace_func_entry *entry; |
4715 | struct ftrace_func_map *map; | |
4716 | void *data; | |
4717 | ||
4718 | entry = ftrace_lookup_ip(&mapper->hash, ip); | |
4719 | if (!entry) | |
4720 | return NULL; | |
4721 | ||
4722 | map = (struct ftrace_func_map *)entry; | |
4723 | data = map->data; | |
4724 | ||
4725 | remove_hash_entry(&mapper->hash, entry); | |
59df055f | 4726 | kfree(entry); |
41794f19 SRV |
4727 | |
4728 | return data; | |
4729 | } | |
4730 | ||
4731 | /** | |
4732 | * free_ftrace_func_mapper - free a mapping of ips and data | |
4733 | * @mapper: The mapper that has the ip maps | |
4734 | * @free_func: A function to be called on each data item. | |
4735 | * | |
4736 | * This is used to free the function mapper. The @free_func is optional | |
4737 | * and can be used if the data needs to be freed as well. | |
4738 | */ | |
4739 | void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper, | |
4740 | ftrace_mapper_func free_func) | |
4741 | { | |
4742 | struct ftrace_func_entry *entry; | |
4743 | struct ftrace_func_map *map; | |
4744 | struct hlist_head *hhd; | |
04e03d9a WL |
4745 | int size, i; |
4746 | ||
4747 | if (!mapper) | |
4748 | return; | |
41794f19 SRV |
4749 | |
4750 | if (free_func && mapper->hash.count) { | |
04e03d9a | 4751 | size = 1 << mapper->hash.size_bits; |
41794f19 SRV |
4752 | for (i = 0; i < size; i++) { |
4753 | hhd = &mapper->hash.buckets[i]; | |
4754 | hlist_for_each_entry(entry, hhd, hlist) { | |
4755 | map = (struct ftrace_func_map *)entry; | |
4756 | free_func(map); | |
4757 | } | |
4758 | } | |
4759 | } | |
4760 | free_ftrace_hash(&mapper->hash); | |
4761 | } | |
4762 | ||
7b60f3d8 SRV |
4763 | static void release_probe(struct ftrace_func_probe *probe) |
4764 | { | |
4765 | struct ftrace_probe_ops *probe_ops; | |
4766 | ||
4767 | mutex_lock(&ftrace_lock); | |
4768 | ||
4769 | WARN_ON(probe->ref <= 0); | |
4770 | ||
4771 | /* Subtract the ref that was used to protect this instance */ | |
4772 | probe->ref--; | |
4773 | ||
4774 | if (!probe->ref) { | |
4775 | probe_ops = probe->probe_ops; | |
6e444319 SRV |
4776 | /* |
4777 | * Sending zero as ip tells probe_ops to free | |
4778 | * the probe->data itself | |
4779 | */ | |
4780 | if (probe_ops->free) | |
4781 | probe_ops->free(probe_ops, probe->tr, 0, probe->data); | |
7b60f3d8 SRV |
4782 | list_del(&probe->list); |
4783 | kfree(probe); | |
4784 | } | |
4785 | mutex_unlock(&ftrace_lock); | |
4786 | } | |
4787 | ||
4788 | static void acquire_probe_locked(struct ftrace_func_probe *probe) | |
4789 | { | |
4790 | /* | |
4791 | * Add one ref to keep it from being freed when releasing the | |
4792 | * ftrace_lock mutex. | |
4793 | */ | |
4794 | probe->ref++; | |
59df055f SR |
4795 | } |
4796 | ||
59df055f | 4797 | int |
04ec7bb6 | 4798 | register_ftrace_function_probe(char *glob, struct trace_array *tr, |
7b60f3d8 SRV |
4799 | struct ftrace_probe_ops *probe_ops, |
4800 | void *data) | |
59df055f | 4801 | { |
ba27d855 | 4802 | struct ftrace_func_probe *probe = NULL, *iter; |
1ec3a81a | 4803 | struct ftrace_func_entry *entry; |
1ec3a81a SRV |
4804 | struct ftrace_hash **orig_hash; |
4805 | struct ftrace_hash *old_hash; | |
e1df4cb6 | 4806 | struct ftrace_hash *hash; |
59df055f | 4807 | int count = 0; |
1ec3a81a | 4808 | int size; |
e1df4cb6 | 4809 | int ret; |
1ec3a81a | 4810 | int i; |
59df055f | 4811 | |
04ec7bb6 | 4812 | if (WARN_ON(!tr)) |
59df055f SR |
4813 | return -EINVAL; |
4814 | ||
1ec3a81a SRV |
4815 | /* We do not support '!' for function probes */ |
4816 | if (WARN_ON(glob[0] == '!')) | |
59df055f | 4817 | return -EINVAL; |
59df055f | 4818 | |
7485058e | 4819 | |
7b60f3d8 SRV |
4820 | mutex_lock(&ftrace_lock); |
4821 | /* Check if the probe_ops is already registered */ | |
ba27d855 JK |
4822 | list_for_each_entry(iter, &tr->func_probes, list) { |
4823 | if (iter->probe_ops == probe_ops) { | |
4824 | probe = iter; | |
7b60f3d8 | 4825 | break; |
ba27d855 | 4826 | } |
e1df4cb6 | 4827 | } |
ba27d855 | 4828 | if (!probe) { |
7b60f3d8 SRV |
4829 | probe = kzalloc(sizeof(*probe), GFP_KERNEL); |
4830 | if (!probe) { | |
4831 | mutex_unlock(&ftrace_lock); | |
4832 | return -ENOMEM; | |
4833 | } | |
4834 | probe->probe_ops = probe_ops; | |
4835 | probe->ops.func = function_trace_probe_call; | |
4836 | probe->tr = tr; | |
4837 | ftrace_ops_init(&probe->ops); | |
4838 | list_add(&probe->list, &tr->func_probes); | |
e1df4cb6 | 4839 | } |
59df055f | 4840 | |
7b60f3d8 | 4841 | acquire_probe_locked(probe); |
5ae0bf59 | 4842 | |
7b60f3d8 | 4843 | mutex_unlock(&ftrace_lock); |
59df055f | 4844 | |
372e0d01 SRV |
4845 | /* |
4846 | * Note, there's a small window here that the func_hash->filter_hash | |
fdda88d3 | 4847 | * may be NULL or empty. Need to be careful when reading the loop. |
372e0d01 | 4848 | */ |
7b60f3d8 | 4849 | mutex_lock(&probe->ops.func_hash->regex_lock); |
546fece4 | 4850 | |
7b60f3d8 | 4851 | orig_hash = &probe->ops.func_hash->filter_hash; |
1ec3a81a SRV |
4852 | old_hash = *orig_hash; |
4853 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash); | |
59df055f | 4854 | |
5b0022dd NR |
4855 | if (!hash) { |
4856 | ret = -ENOMEM; | |
4857 | goto out; | |
4858 | } | |
4859 | ||
1ec3a81a | 4860 | ret = ftrace_match_records(hash, glob, strlen(glob)); |
59df055f | 4861 | |
1ec3a81a SRV |
4862 | /* Nothing found? */ |
4863 | if (!ret) | |
4864 | ret = -EINVAL; | |
59df055f | 4865 | |
1ec3a81a SRV |
4866 | if (ret < 0) |
4867 | goto out; | |
59df055f | 4868 | |
1ec3a81a SRV |
4869 | size = 1 << hash->size_bits; |
4870 | for (i = 0; i < size; i++) { | |
4871 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { | |
4872 | if (ftrace_lookup_ip(old_hash, entry->ip)) | |
59df055f | 4873 | continue; |
1ec3a81a SRV |
4874 | /* |
4875 | * The caller might want to do something special | |
4876 | * for each function we find. We call the callback | |
4877 | * to give the caller an opportunity to do so. | |
4878 | */ | |
7b60f3d8 SRV |
4879 | if (probe_ops->init) { |
4880 | ret = probe_ops->init(probe_ops, tr, | |
6e444319 SRV |
4881 | entry->ip, data, |
4882 | &probe->data); | |
4883 | if (ret < 0) { | |
4884 | if (probe_ops->free && count) | |
4885 | probe_ops->free(probe_ops, tr, | |
4886 | 0, probe->data); | |
4887 | probe->data = NULL; | |
eee8ded1 | 4888 | goto out; |
6e444319 | 4889 | } |
59df055f | 4890 | } |
1ec3a81a | 4891 | count++; |
59df055f | 4892 | } |
1ec3a81a | 4893 | } |
59df055f | 4894 | |
1ec3a81a | 4895 | mutex_lock(&ftrace_lock); |
59df055f | 4896 | |
7b60f3d8 SRV |
4897 | if (!count) { |
4898 | /* Nothing was added? */ | |
4899 | ret = -EINVAL; | |
4900 | goto out_unlock; | |
4901 | } | |
e1df4cb6 | 4902 | |
7b60f3d8 SRV |
4903 | ret = ftrace_hash_move_and_update_ops(&probe->ops, orig_hash, |
4904 | hash, 1); | |
1ec3a81a | 4905 | if (ret < 0) |
8d70725e | 4906 | goto err_unlock; |
8252ecf3 | 4907 | |
7b60f3d8 SRV |
4908 | /* One ref for each new function traced */ |
4909 | probe->ref += count; | |
8252ecf3 | 4910 | |
7b60f3d8 SRV |
4911 | if (!(probe->ops.flags & FTRACE_OPS_FL_ENABLED)) |
4912 | ret = ftrace_startup(&probe->ops, 0); | |
e1df4cb6 | 4913 | |
59df055f | 4914 | out_unlock: |
5ae0bf59 | 4915 | mutex_unlock(&ftrace_lock); |
8252ecf3 | 4916 | |
3296fc4e | 4917 | if (!ret) |
1ec3a81a | 4918 | ret = count; |
5ae0bf59 | 4919 | out: |
7b60f3d8 | 4920 | mutex_unlock(&probe->ops.func_hash->regex_lock); |
e1df4cb6 | 4921 | free_ftrace_hash(hash); |
59df055f | 4922 | |
7b60f3d8 | 4923 | release_probe(probe); |
59df055f | 4924 | |
1ec3a81a | 4925 | return ret; |
59df055f | 4926 | |
8d70725e | 4927 | err_unlock: |
7b60f3d8 | 4928 | if (!probe_ops->free || !count) |
8d70725e SRV |
4929 | goto out_unlock; |
4930 | ||
4931 | /* Failed to do the move, need to call the free functions */ | |
4932 | for (i = 0; i < size; i++) { | |
4933 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { | |
4934 | if (ftrace_lookup_ip(old_hash, entry->ip)) | |
4935 | continue; | |
6e444319 | 4936 | probe_ops->free(probe_ops, tr, entry->ip, probe->data); |
8d70725e SRV |
4937 | } |
4938 | } | |
4939 | goto out_unlock; | |
59df055f SR |
4940 | } |
4941 | ||
d3d532d7 | 4942 | int |
7b60f3d8 SRV |
4943 | unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr, |
4944 | struct ftrace_probe_ops *probe_ops) | |
59df055f | 4945 | { |
ba27d855 | 4946 | struct ftrace_func_probe *probe = NULL, *iter; |
82cc4fc2 | 4947 | struct ftrace_ops_hash old_hash_ops; |
eee8ded1 | 4948 | struct ftrace_func_entry *entry; |
3ba00929 | 4949 | struct ftrace_glob func_g; |
1ec3a81a SRV |
4950 | struct ftrace_hash **orig_hash; |
4951 | struct ftrace_hash *old_hash; | |
1ec3a81a | 4952 | struct ftrace_hash *hash = NULL; |
b67bfe0d | 4953 | struct hlist_node *tmp; |
eee8ded1 | 4954 | struct hlist_head hhd; |
59df055f | 4955 | char str[KSYM_SYMBOL_LEN]; |
7b60f3d8 SRV |
4956 | int count = 0; |
4957 | int i, ret = -ENODEV; | |
eee8ded1 | 4958 | int size; |
59df055f | 4959 | |
cbab567c | 4960 | if (!glob || !strlen(glob) || !strcmp(glob, "*")) |
3ba00929 | 4961 | func_g.search = NULL; |
cbab567c | 4962 | else { |
59df055f SR |
4963 | int not; |
4964 | ||
3ba00929 DS |
4965 | func_g.type = filter_parse_regex(glob, strlen(glob), |
4966 | &func_g.search, ¬); | |
4967 | func_g.len = strlen(func_g.search); | |
59df055f | 4968 | |
b6887d79 | 4969 | /* we do not support '!' for function probes */ |
59df055f | 4970 | if (WARN_ON(not)) |
d3d532d7 | 4971 | return -EINVAL; |
59df055f SR |
4972 | } |
4973 | ||
7b60f3d8 SRV |
4974 | mutex_lock(&ftrace_lock); |
4975 | /* Check if the probe_ops is already registered */ | |
ba27d855 JK |
4976 | list_for_each_entry(iter, &tr->func_probes, list) { |
4977 | if (iter->probe_ops == probe_ops) { | |
4978 | probe = iter; | |
7b60f3d8 | 4979 | break; |
ba27d855 | 4980 | } |
59df055f | 4981 | } |
ba27d855 | 4982 | if (!probe) |
7b60f3d8 SRV |
4983 | goto err_unlock_ftrace; |
4984 | ||
4985 | ret = -EINVAL; | |
4986 | if (!(probe->ops.flags & FTRACE_OPS_FL_INITIALIZED)) | |
4987 | goto err_unlock_ftrace; | |
4988 | ||
4989 | acquire_probe_locked(probe); | |
4990 | ||
4991 | mutex_unlock(&ftrace_lock); | |
59df055f | 4992 | |
7b60f3d8 | 4993 | mutex_lock(&probe->ops.func_hash->regex_lock); |
1ec3a81a | 4994 | |
7b60f3d8 | 4995 | orig_hash = &probe->ops.func_hash->filter_hash; |
1ec3a81a SRV |
4996 | old_hash = *orig_hash; |
4997 | ||
1ec3a81a SRV |
4998 | if (ftrace_hash_empty(old_hash)) |
4999 | goto out_unlock; | |
e1df4cb6 | 5000 | |
82cc4fc2 SRV |
5001 | old_hash_ops.filter_hash = old_hash; |
5002 | /* Probes only have filters */ | |
5003 | old_hash_ops.notrace_hash = NULL; | |
5004 | ||
d3d532d7 | 5005 | ret = -ENOMEM; |
1ec3a81a | 5006 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash); |
e1df4cb6 | 5007 | if (!hash) |
e1df4cb6 SRRH |
5008 | goto out_unlock; |
5009 | ||
eee8ded1 | 5010 | INIT_HLIST_HEAD(&hhd); |
59df055f | 5011 | |
eee8ded1 SRV |
5012 | size = 1 << hash->size_bits; |
5013 | for (i = 0; i < size; i++) { | |
5014 | hlist_for_each_entry_safe(entry, tmp, &hash->buckets[i], hlist) { | |
59df055f | 5015 | |
3ba00929 | 5016 | if (func_g.search) { |
59df055f SR |
5017 | kallsyms_lookup(entry->ip, NULL, NULL, |
5018 | NULL, str); | |
3ba00929 | 5019 | if (!ftrace_match(str, &func_g)) |
59df055f SR |
5020 | continue; |
5021 | } | |
7b60f3d8 | 5022 | count++; |
eee8ded1 SRV |
5023 | remove_hash_entry(hash, entry); |
5024 | hlist_add_head(&entry->hlist, &hhd); | |
59df055f SR |
5025 | } |
5026 | } | |
d3d532d7 SRV |
5027 | |
5028 | /* Nothing found? */ | |
7b60f3d8 | 5029 | if (!count) { |
d3d532d7 SRV |
5030 | ret = -EINVAL; |
5031 | goto out_unlock; | |
5032 | } | |
5033 | ||
3f2367ba | 5034 | mutex_lock(&ftrace_lock); |
1ec3a81a | 5035 | |
7b60f3d8 | 5036 | WARN_ON(probe->ref < count); |
eee8ded1 | 5037 | |
7b60f3d8 | 5038 | probe->ref -= count; |
1ec3a81a | 5039 | |
7b60f3d8 SRV |
5040 | if (ftrace_hash_empty(hash)) |
5041 | ftrace_shutdown(&probe->ops, 0); | |
5042 | ||
5043 | ret = ftrace_hash_move_and_update_ops(&probe->ops, orig_hash, | |
1ec3a81a | 5044 | hash, 1); |
82cc4fc2 SRV |
5045 | |
5046 | /* still need to update the function call sites */ | |
1ec3a81a | 5047 | if (ftrace_enabled && !ftrace_hash_empty(hash)) |
7b60f3d8 | 5048 | ftrace_run_modify_code(&probe->ops, FTRACE_UPDATE_CALLS, |
82cc4fc2 | 5049 | &old_hash_ops); |
74401729 | 5050 | synchronize_rcu(); |
3296fc4e | 5051 | |
eee8ded1 SRV |
5052 | hlist_for_each_entry_safe(entry, tmp, &hhd, hlist) { |
5053 | hlist_del(&entry->hlist); | |
7b60f3d8 | 5054 | if (probe_ops->free) |
6e444319 | 5055 | probe_ops->free(probe_ops, tr, entry->ip, probe->data); |
eee8ded1 | 5056 | kfree(entry); |
7818b388 | 5057 | } |
3f2367ba | 5058 | mutex_unlock(&ftrace_lock); |
3ba00929 | 5059 | |
e1df4cb6 | 5060 | out_unlock: |
7b60f3d8 | 5061 | mutex_unlock(&probe->ops.func_hash->regex_lock); |
e1df4cb6 | 5062 | free_ftrace_hash(hash); |
59df055f | 5063 | |
7b60f3d8 | 5064 | release_probe(probe); |
59df055f | 5065 | |
7b60f3d8 | 5066 | return ret; |
59df055f | 5067 | |
7b60f3d8 SRV |
5068 | err_unlock_ftrace: |
5069 | mutex_unlock(&ftrace_lock); | |
d3d532d7 | 5070 | return ret; |
59df055f SR |
5071 | } |
5072 | ||
a0e6369e NR |
5073 | void clear_ftrace_function_probes(struct trace_array *tr) |
5074 | { | |
5075 | struct ftrace_func_probe *probe, *n; | |
5076 | ||
5077 | list_for_each_entry_safe(probe, n, &tr->func_probes, list) | |
5078 | unregister_ftrace_function_probe_func(NULL, tr, probe->probe_ops); | |
5079 | } | |
5080 | ||
f6180773 SR |
5081 | static LIST_HEAD(ftrace_commands); |
5082 | static DEFINE_MUTEX(ftrace_cmd_mutex); | |
5083 | ||
38de93ab TZ |
5084 | /* |
5085 | * Currently we only register ftrace commands from __init, so mark this | |
5086 | * __init too. | |
5087 | */ | |
5088 | __init int register_ftrace_command(struct ftrace_func_command *cmd) | |
f6180773 SR |
5089 | { |
5090 | struct ftrace_func_command *p; | |
5091 | int ret = 0; | |
5092 | ||
5093 | mutex_lock(&ftrace_cmd_mutex); | |
5094 | list_for_each_entry(p, &ftrace_commands, list) { | |
5095 | if (strcmp(cmd->name, p->name) == 0) { | |
5096 | ret = -EBUSY; | |
5097 | goto out_unlock; | |
5098 | } | |
5099 | } | |
5100 | list_add(&cmd->list, &ftrace_commands); | |
5101 | out_unlock: | |
5102 | mutex_unlock(&ftrace_cmd_mutex); | |
5103 | ||
5104 | return ret; | |
5105 | } | |
5106 | ||
38de93ab TZ |
5107 | /* |
5108 | * Currently we only unregister ftrace commands from __init, so mark | |
5109 | * this __init too. | |
5110 | */ | |
5111 | __init int unregister_ftrace_command(struct ftrace_func_command *cmd) | |
f6180773 SR |
5112 | { |
5113 | struct ftrace_func_command *p, *n; | |
5114 | int ret = -ENODEV; | |
5115 | ||
5116 | mutex_lock(&ftrace_cmd_mutex); | |
5117 | list_for_each_entry_safe(p, n, &ftrace_commands, list) { | |
5118 | if (strcmp(cmd->name, p->name) == 0) { | |
5119 | ret = 0; | |
5120 | list_del_init(&p->list); | |
5121 | goto out_unlock; | |
5122 | } | |
5123 | } | |
5124 | out_unlock: | |
5125 | mutex_unlock(&ftrace_cmd_mutex); | |
5126 | ||
5127 | return ret; | |
5128 | } | |
5129 | ||
04ec7bb6 | 5130 | static int ftrace_process_regex(struct ftrace_iterator *iter, |
33dc9b12 | 5131 | char *buff, int len, int enable) |
64e7c440 | 5132 | { |
04ec7bb6 | 5133 | struct ftrace_hash *hash = iter->hash; |
d2afd57a | 5134 | struct trace_array *tr = iter->ops->private; |
f6180773 | 5135 | char *func, *command, *next = buff; |
6a24a244 | 5136 | struct ftrace_func_command *p; |
0aff1c0c | 5137 | int ret = -EINVAL; |
64e7c440 SR |
5138 | |
5139 | func = strsep(&next, ":"); | |
5140 | ||
5141 | if (!next) { | |
1cf41dd7 | 5142 | ret = ftrace_match_records(hash, func, len); |
b448c4e3 SR |
5143 | if (!ret) |
5144 | ret = -EINVAL; | |
5145 | if (ret < 0) | |
5146 | return ret; | |
5147 | return 0; | |
64e7c440 SR |
5148 | } |
5149 | ||
f6180773 | 5150 | /* command found */ |
64e7c440 SR |
5151 | |
5152 | command = strsep(&next, ":"); | |
5153 | ||
f6180773 SR |
5154 | mutex_lock(&ftrace_cmd_mutex); |
5155 | list_for_each_entry(p, &ftrace_commands, list) { | |
5156 | if (strcmp(p->name, command) == 0) { | |
04ec7bb6 | 5157 | ret = p->func(tr, hash, func, command, next, enable); |
f6180773 SR |
5158 | goto out_unlock; |
5159 | } | |
64e7c440 | 5160 | } |
f6180773 SR |
5161 | out_unlock: |
5162 | mutex_unlock(&ftrace_cmd_mutex); | |
64e7c440 | 5163 | |
f6180773 | 5164 | return ret; |
64e7c440 SR |
5165 | } |
5166 | ||
e309b41d | 5167 | static ssize_t |
41c52c0d SR |
5168 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
5169 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
5170 | { |
5171 | struct ftrace_iterator *iter; | |
689fd8b6 | 5172 | struct trace_parser *parser; |
5173 | ssize_t ret, read; | |
5072c59f | 5174 | |
4ba7978e | 5175 | if (!cnt) |
5072c59f SR |
5176 | return 0; |
5177 | ||
5072c59f SR |
5178 | if (file->f_mode & FMODE_READ) { |
5179 | struct seq_file *m = file->private_data; | |
5180 | iter = m->private; | |
5181 | } else | |
5182 | iter = file->private_data; | |
5183 | ||
f04f24fb | 5184 | if (unlikely(ftrace_disabled)) |
3f2367ba MH |
5185 | return -ENODEV; |
5186 | ||
5187 | /* iter->hash is a local copy, so we don't need regex_lock */ | |
f04f24fb | 5188 | |
689fd8b6 | 5189 | parser = &iter->parser; |
5190 | read = trace_get_user(parser, ubuf, cnt, ppos); | |
5072c59f | 5191 | |
4ba7978e | 5192 | if (read >= 0 && trace_parser_loaded(parser) && |
689fd8b6 | 5193 | !trace_parser_cont(parser)) { |
04ec7bb6 | 5194 | ret = ftrace_process_regex(iter, parser->buffer, |
689fd8b6 | 5195 | parser->idx, enable); |
313254a9 | 5196 | trace_parser_clear(parser); |
7c088b51 | 5197 | if (ret < 0) |
3f2367ba | 5198 | goto out; |
eda1e328 | 5199 | } |
5072c59f | 5200 | |
5072c59f | 5201 | ret = read; |
3f2367ba | 5202 | out: |
5072c59f SR |
5203 | return ret; |
5204 | } | |
5205 | ||
fc13cb0c | 5206 | ssize_t |
41c52c0d SR |
5207 | ftrace_filter_write(struct file *file, const char __user *ubuf, |
5208 | size_t cnt, loff_t *ppos) | |
5209 | { | |
5210 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
5211 | } | |
5212 | ||
fc13cb0c | 5213 | ssize_t |
41c52c0d SR |
5214 | ftrace_notrace_write(struct file *file, const char __user *ubuf, |
5215 | size_t cnt, loff_t *ppos) | |
5216 | { | |
5217 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
5218 | } | |
5219 | ||
33dc9b12 | 5220 | static int |
4f554e95 | 5221 | __ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove) |
647664ea MH |
5222 | { |
5223 | struct ftrace_func_entry *entry; | |
5224 | ||
aebfd125 PZ |
5225 | ip = ftrace_location(ip); |
5226 | if (!ip) | |
647664ea MH |
5227 | return -EINVAL; |
5228 | ||
5229 | if (remove) { | |
5230 | entry = ftrace_lookup_ip(hash, ip); | |
5231 | if (!entry) | |
5232 | return -ENOENT; | |
5233 | free_hash_entry(hash, entry); | |
5234 | return 0; | |
5235 | } | |
5236 | ||
d05cb470 SRG |
5237 | entry = add_hash_entry(hash, ip); |
5238 | return entry ? 0 : -ENOMEM; | |
647664ea MH |
5239 | } |
5240 | ||
4f554e95 JO |
5241 | static int |
5242 | ftrace_match_addr(struct ftrace_hash *hash, unsigned long *ips, | |
5243 | unsigned int cnt, int remove) | |
5244 | { | |
5245 | unsigned int i; | |
5246 | int err; | |
5247 | ||
5248 | for (i = 0; i < cnt; i++) { | |
5249 | err = __ftrace_match_addr(hash, ips[i], remove); | |
5250 | if (err) { | |
5251 | /* | |
5252 | * This expects the @hash is a temporary hash and if this | |
5253 | * fails the caller must free the @hash. | |
5254 | */ | |
5255 | return err; | |
5256 | } | |
5257 | } | |
5258 | return 0; | |
5259 | } | |
5260 | ||
647664ea MH |
5261 | static int |
5262 | ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len, | |
4f554e95 JO |
5263 | unsigned long *ips, unsigned int cnt, |
5264 | int remove, int reset, int enable) | |
41c52c0d | 5265 | { |
33dc9b12 | 5266 | struct ftrace_hash **orig_hash; |
f45948e8 | 5267 | struct ftrace_hash *hash; |
33dc9b12 | 5268 | int ret; |
f45948e8 | 5269 | |
41c52c0d | 5270 | if (unlikely(ftrace_disabled)) |
33dc9b12 | 5271 | return -ENODEV; |
41c52c0d | 5272 | |
33b7f99c | 5273 | mutex_lock(&ops->func_hash->regex_lock); |
3f2367ba | 5274 | |
f45948e8 | 5275 | if (enable) |
33b7f99c | 5276 | orig_hash = &ops->func_hash->filter_hash; |
f45948e8 | 5277 | else |
33b7f99c | 5278 | orig_hash = &ops->func_hash->notrace_hash; |
33dc9b12 | 5279 | |
b972cc58 WN |
5280 | if (reset) |
5281 | hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS); | |
5282 | else | |
5283 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); | |
5284 | ||
3f2367ba MH |
5285 | if (!hash) { |
5286 | ret = -ENOMEM; | |
5287 | goto out_regex_unlock; | |
5288 | } | |
f45948e8 | 5289 | |
ac483c44 JO |
5290 | if (buf && !ftrace_match_records(hash, buf, len)) { |
5291 | ret = -EINVAL; | |
5292 | goto out_regex_unlock; | |
5293 | } | |
4f554e95 JO |
5294 | if (ips) { |
5295 | ret = ftrace_match_addr(hash, ips, cnt, remove); | |
647664ea MH |
5296 | if (ret < 0) |
5297 | goto out_regex_unlock; | |
5298 | } | |
33dc9b12 SR |
5299 | |
5300 | mutex_lock(&ftrace_lock); | |
e16b35dd | 5301 | ret = ftrace_hash_move_and_update_ops(ops, orig_hash, hash, enable); |
33dc9b12 SR |
5302 | mutex_unlock(&ftrace_lock); |
5303 | ||
ac483c44 | 5304 | out_regex_unlock: |
33b7f99c | 5305 | mutex_unlock(&ops->func_hash->regex_lock); |
33dc9b12 SR |
5306 | |
5307 | free_ftrace_hash(hash); | |
5308 | return ret; | |
41c52c0d SR |
5309 | } |
5310 | ||
647664ea | 5311 | static int |
4f554e95 JO |
5312 | ftrace_set_addr(struct ftrace_ops *ops, unsigned long *ips, unsigned int cnt, |
5313 | int remove, int reset, int enable) | |
647664ea | 5314 | { |
4f554e95 | 5315 | return ftrace_set_hash(ops, NULL, 0, ips, cnt, remove, reset, enable); |
647664ea MH |
5316 | } |
5317 | ||
763e34e7 | 5318 | #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS |
013bf0da SRV |
5319 | |
5320 | struct ftrace_direct_func { | |
5321 | struct list_head next; | |
5322 | unsigned long addr; | |
5323 | int count; | |
5324 | }; | |
5325 | ||
5326 | static LIST_HEAD(ftrace_direct_funcs); | |
5327 | ||
53cd885b SL |
5328 | static int register_ftrace_function_nolock(struct ftrace_ops *ops); |
5329 | ||
a8b9cf62 MHG |
5330 | /* |
5331 | * If there are multiple ftrace_ops, use SAVE_REGS by default, so that direct | |
5332 | * call will be jumped from ftrace_regs_caller. Only if the architecture does | |
5333 | * not support ftrace_regs_caller but direct_call, use SAVE_ARGS so that it | |
5334 | * jumps from ftrace_caller for multiple ftrace_ops. | |
5335 | */ | |
bdbddb10 | 5336 | #ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_REGS |
60c89718 | 5337 | #define MULTI_FLAGS (FTRACE_OPS_FL_DIRECT | FTRACE_OPS_FL_SAVE_ARGS) |
a8b9cf62 MHG |
5338 | #else |
5339 | #define MULTI_FLAGS (FTRACE_OPS_FL_DIRECT | FTRACE_OPS_FL_SAVE_REGS) | |
5340 | #endif | |
f64dd462 JO |
5341 | |
5342 | static int check_direct_multi(struct ftrace_ops *ops) | |
5343 | { | |
5344 | if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) | |
5345 | return -EINVAL; | |
5346 | if ((ops->flags & MULTI_FLAGS) != MULTI_FLAGS) | |
5347 | return -EINVAL; | |
5348 | return 0; | |
5349 | } | |
5350 | ||
5351 | static void remove_direct_functions_hash(struct ftrace_hash *hash, unsigned long addr) | |
5352 | { | |
5353 | struct ftrace_func_entry *entry, *del; | |
5354 | int size, i; | |
5355 | ||
5356 | size = 1 << hash->size_bits; | |
5357 | for (i = 0; i < size; i++) { | |
5358 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { | |
5359 | del = __ftrace_lookup_ip(direct_functions, entry->ip); | |
5360 | if (del && del->direct == addr) { | |
5361 | remove_hash_entry(direct_functions, del); | |
5362 | kfree(del); | |
5363 | } | |
5364 | } | |
5365 | } | |
5366 | } | |
5367 | ||
5368 | /** | |
da8bdfbd | 5369 | * register_ftrace_direct - Call a custom trampoline directly |
f64dd462 JO |
5370 | * for multiple functions registered in @ops |
5371 | * @ops: The address of the struct ftrace_ops object | |
5372 | * @addr: The address of the trampoline to call at @ops functions | |
5373 | * | |
5374 | * This is used to connect a direct calls to @addr from the nop locations | |
5375 | * of the functions registered in @ops (with by ftrace_set_filter_ip | |
5376 | * function). | |
5377 | * | |
5378 | * The location that it calls (@addr) must be able to handle a direct call, | |
5379 | * and save the parameters of the function being traced, and restore them | |
5380 | * (or inject new ones if needed), before returning. | |
5381 | * | |
5382 | * Returns: | |
5383 | * 0 on success | |
5384 | * -EINVAL - The @ops object was already registered with this call or | |
5385 | * when there are no functions in @ops object. | |
5386 | * -EBUSY - Another direct function is already attached (there can be only one) | |
5387 | * -ENODEV - @ip does not point to a ftrace nop location (or not supported) | |
5388 | * -ENOMEM - There was an allocation failure. | |
5389 | */ | |
da8bdfbd | 5390 | int register_ftrace_direct(struct ftrace_ops *ops, unsigned long addr) |
f64dd462 | 5391 | { |
d05cb470 | 5392 | struct ftrace_hash *hash, *new_hash = NULL, *free_hash = NULL; |
f64dd462 JO |
5393 | struct ftrace_func_entry *entry, *new; |
5394 | int err = -EBUSY, size, i; | |
5395 | ||
5396 | if (ops->func || ops->trampoline) | |
5397 | return -EINVAL; | |
5398 | if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) | |
5399 | return -EINVAL; | |
5400 | if (ops->flags & FTRACE_OPS_FL_ENABLED) | |
5401 | return -EINVAL; | |
5402 | ||
5403 | hash = ops->func_hash->filter_hash; | |
5404 | if (ftrace_hash_empty(hash)) | |
5405 | return -EINVAL; | |
5406 | ||
5407 | mutex_lock(&direct_mutex); | |
5408 | ||
5409 | /* Make sure requested entries are not already registered.. */ | |
5410 | size = 1 << hash->size_bits; | |
5411 | for (i = 0; i < size; i++) { | |
5412 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { | |
5413 | if (ftrace_find_rec_direct(entry->ip)) | |
5414 | goto out_unlock; | |
5415 | } | |
5416 | } | |
5417 | ||
f64dd462 | 5418 | err = -ENOMEM; |
d05cb470 SRG |
5419 | |
5420 | /* Make a copy hash to place the new and the old entries in */ | |
5421 | size = hash->count + direct_functions->count; | |
5422 | if (size > 32) | |
5423 | size = 32; | |
5424 | new_hash = alloc_ftrace_hash(fls(size)); | |
5425 | if (!new_hash) | |
5426 | goto out_unlock; | |
5427 | ||
5428 | /* Now copy over the existing direct entries */ | |
5429 | size = 1 << direct_functions->size_bits; | |
5430 | for (i = 0; i < size; i++) { | |
5431 | hlist_for_each_entry(entry, &direct_functions->buckets[i], hlist) { | |
5432 | new = add_hash_entry(new_hash, entry->ip); | |
5433 | if (!new) | |
5434 | goto out_unlock; | |
5435 | new->direct = entry->direct; | |
5436 | } | |
5437 | } | |
5438 | ||
5439 | /* ... and add the new entries */ | |
5440 | size = 1 << hash->size_bits; | |
f64dd462 JO |
5441 | for (i = 0; i < size; i++) { |
5442 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { | |
d05cb470 | 5443 | new = add_hash_entry(new_hash, entry->ip); |
f64dd462 | 5444 | if (!new) |
d05cb470 SRG |
5445 | goto out_unlock; |
5446 | /* Update both the copy and the hash entry */ | |
5447 | new->direct = addr; | |
f64dd462 JO |
5448 | entry->direct = addr; |
5449 | } | |
5450 | } | |
5451 | ||
d05cb470 SRG |
5452 | free_hash = direct_functions; |
5453 | rcu_assign_pointer(direct_functions, new_hash); | |
5454 | new_hash = NULL; | |
5455 | ||
f64dd462 JO |
5456 | ops->func = call_direct_funcs; |
5457 | ops->flags = MULTI_FLAGS; | |
5458 | ops->trampoline = FTRACE_REGS_ADDR; | |
dbaccb61 | 5459 | ops->direct_call = addr; |
f64dd462 | 5460 | |
53cd885b | 5461 | err = register_ftrace_function_nolock(ops); |
f64dd462 | 5462 | |
f64dd462 JO |
5463 | out_unlock: |
5464 | mutex_unlock(&direct_mutex); | |
5465 | ||
d05cb470 | 5466 | if (free_hash && free_hash != EMPTY_HASH) { |
f64dd462 JO |
5467 | synchronize_rcu_tasks(); |
5468 | free_ftrace_hash(free_hash); | |
5469 | } | |
d05cb470 SRG |
5470 | |
5471 | if (new_hash) | |
5472 | free_ftrace_hash(new_hash); | |
5473 | ||
f64dd462 JO |
5474 | return err; |
5475 | } | |
da8bdfbd | 5476 | EXPORT_SYMBOL_GPL(register_ftrace_direct); |
f64dd462 JO |
5477 | |
5478 | /** | |
da8bdfbd FR |
5479 | * unregister_ftrace_direct - Remove calls to custom trampoline |
5480 | * previously registered by register_ftrace_direct for @ops object. | |
f64dd462 JO |
5481 | * @ops: The address of the struct ftrace_ops object |
5482 | * | |
5483 | * This is used to remove a direct calls to @addr from the nop locations | |
5484 | * of the functions registered in @ops (with by ftrace_set_filter_ip | |
5485 | * function). | |
5486 | * | |
5487 | * Returns: | |
5488 | * 0 on success | |
5489 | * -EINVAL - The @ops object was not properly registered. | |
5490 | */ | |
da8bdfbd FR |
5491 | int unregister_ftrace_direct(struct ftrace_ops *ops, unsigned long addr, |
5492 | bool free_filters) | |
f64dd462 JO |
5493 | { |
5494 | struct ftrace_hash *hash = ops->func_hash->filter_hash; | |
5495 | int err; | |
5496 | ||
5497 | if (check_direct_multi(ops)) | |
5498 | return -EINVAL; | |
5499 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
5500 | return -EINVAL; | |
5501 | ||
5502 | mutex_lock(&direct_mutex); | |
5503 | err = unregister_ftrace_function(ops); | |
5504 | remove_direct_functions_hash(hash, addr); | |
5505 | mutex_unlock(&direct_mutex); | |
fea3ffa4 JO |
5506 | |
5507 | /* cleanup for possible another register call */ | |
5508 | ops->func = NULL; | |
5509 | ops->trampoline = 0; | |
59495740 FR |
5510 | |
5511 | if (free_filters) | |
5512 | ftrace_free_filter(ops); | |
f64dd462 JO |
5513 | return err; |
5514 | } | |
da8bdfbd | 5515 | EXPORT_SYMBOL_GPL(unregister_ftrace_direct); |
ccf5a89e | 5516 | |
f96f644a | 5517 | static int |
da8bdfbd | 5518 | __modify_ftrace_direct(struct ftrace_ops *ops, unsigned long addr) |
ccf5a89e | 5519 | { |
ed292718 | 5520 | struct ftrace_hash *hash; |
ccf5a89e | 5521 | struct ftrace_func_entry *entry, *iter; |
ed292718 SRV |
5522 | static struct ftrace_ops tmp_ops = { |
5523 | .func = ftrace_stub, | |
5524 | .flags = FTRACE_OPS_FL_STUB, | |
5525 | }; | |
ccf5a89e JO |
5526 | int i, size; |
5527 | int err; | |
5528 | ||
f96f644a | 5529 | lockdep_assert_held_once(&direct_mutex); |
ed292718 SRV |
5530 | |
5531 | /* Enable the tmp_ops to have the same functions as the direct ops */ | |
5532 | ftrace_ops_init(&tmp_ops); | |
5533 | tmp_ops.func_hash = ops->func_hash; | |
dbaccb61 | 5534 | tmp_ops.direct_call = addr; |
ed292718 | 5535 | |
53cd885b | 5536 | err = register_ftrace_function_nolock(&tmp_ops); |
ed292718 | 5537 | if (err) |
f96f644a | 5538 | return err; |
ccf5a89e JO |
5539 | |
5540 | /* | |
ed292718 SRV |
5541 | * Now the ftrace_ops_list_func() is called to do the direct callers. |
5542 | * We can safely change the direct functions attached to each entry. | |
ccf5a89e | 5543 | */ |
ed292718 | 5544 | mutex_lock(&ftrace_lock); |
ccf5a89e | 5545 | |
ed292718 | 5546 | hash = ops->func_hash->filter_hash; |
ccf5a89e JO |
5547 | size = 1 << hash->size_bits; |
5548 | for (i = 0; i < size; i++) { | |
5549 | hlist_for_each_entry(iter, &hash->buckets[i], hlist) { | |
5550 | entry = __ftrace_lookup_ip(direct_functions, iter->ip); | |
5551 | if (!entry) | |
5552 | continue; | |
5553 | entry->direct = addr; | |
5554 | } | |
5555 | } | |
dbaccb61 FR |
5556 | /* Prevent store tearing if a trampoline concurrently accesses the value */ |
5557 | WRITE_ONCE(ops->direct_call, addr); | |
ccf5a89e | 5558 | |
2e6e9058 JO |
5559 | mutex_unlock(&ftrace_lock); |
5560 | ||
ed292718 SRV |
5561 | /* Removing the tmp_ops will add the updated direct callers to the functions */ |
5562 | unregister_ftrace_function(&tmp_ops); | |
ccf5a89e | 5563 | |
f96f644a SL |
5564 | return err; |
5565 | } | |
5566 | ||
5567 | /** | |
da8bdfbd | 5568 | * modify_ftrace_direct_nolock - Modify an existing direct 'multi' call |
f96f644a SL |
5569 | * to call something else |
5570 | * @ops: The address of the struct ftrace_ops object | |
5571 | * @addr: The address of the new trampoline to call at @ops functions | |
5572 | * | |
5573 | * This is used to unregister currently registered direct caller and | |
5574 | * register new one @addr on functions registered in @ops object. | |
5575 | * | |
5576 | * Note there's window between ftrace_shutdown and ftrace_startup calls | |
5577 | * where there will be no callbacks called. | |
5578 | * | |
5579 | * Caller should already have direct_mutex locked, so we don't lock | |
5580 | * direct_mutex here. | |
5581 | * | |
5582 | * Returns: zero on success. Non zero on error, which includes: | |
5583 | * -EINVAL - The @ops object was not properly registered. | |
5584 | */ | |
da8bdfbd | 5585 | int modify_ftrace_direct_nolock(struct ftrace_ops *ops, unsigned long addr) |
f96f644a SL |
5586 | { |
5587 | if (check_direct_multi(ops)) | |
5588 | return -EINVAL; | |
5589 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
5590 | return -EINVAL; | |
5591 | ||
da8bdfbd | 5592 | return __modify_ftrace_direct(ops, addr); |
f96f644a | 5593 | } |
da8bdfbd | 5594 | EXPORT_SYMBOL_GPL(modify_ftrace_direct_nolock); |
f96f644a SL |
5595 | |
5596 | /** | |
da8bdfbd | 5597 | * modify_ftrace_direct - Modify an existing direct 'multi' call |
f96f644a SL |
5598 | * to call something else |
5599 | * @ops: The address of the struct ftrace_ops object | |
5600 | * @addr: The address of the new trampoline to call at @ops functions | |
5601 | * | |
5602 | * This is used to unregister currently registered direct caller and | |
5603 | * register new one @addr on functions registered in @ops object. | |
5604 | * | |
5605 | * Note there's window between ftrace_shutdown and ftrace_startup calls | |
5606 | * where there will be no callbacks called. | |
5607 | * | |
5608 | * Returns: zero on success. Non zero on error, which includes: | |
5609 | * -EINVAL - The @ops object was not properly registered. | |
5610 | */ | |
da8bdfbd | 5611 | int modify_ftrace_direct(struct ftrace_ops *ops, unsigned long addr) |
f96f644a SL |
5612 | { |
5613 | int err; | |
5614 | ||
5615 | if (check_direct_multi(ops)) | |
5616 | return -EINVAL; | |
5617 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
5618 | return -EINVAL; | |
5619 | ||
5620 | mutex_lock(&direct_mutex); | |
da8bdfbd | 5621 | err = __modify_ftrace_direct(ops, addr); |
ccf5a89e JO |
5622 | mutex_unlock(&direct_mutex); |
5623 | return err; | |
5624 | } | |
da8bdfbd | 5625 | EXPORT_SYMBOL_GPL(modify_ftrace_direct); |
763e34e7 SRV |
5626 | #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ |
5627 | ||
647664ea MH |
5628 | /** |
5629 | * ftrace_set_filter_ip - set a function to filter on in ftrace by address | |
d1530413 RD |
5630 | * @ops: the ops to set the filter with |
5631 | * @ip: the address to add to or remove from the filter. | |
5632 | * @remove: non zero to remove the ip from the filter | |
5633 | * @reset: non zero to reset all filters before applying this filter. | |
647664ea MH |
5634 | * |
5635 | * Filters denote which functions should be enabled when tracing is enabled | |
f2cc020d | 5636 | * If @ip is NULL, it fails to update filter. |
8be9fbd5 MR |
5637 | * |
5638 | * This can allocate memory which must be freed before @ops can be freed, | |
5639 | * either by removing each filtered addr or by using | |
5640 | * ftrace_free_filter(@ops). | |
647664ea MH |
5641 | */ |
5642 | int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, | |
5643 | int remove, int reset) | |
5644 | { | |
f04f24fb | 5645 | ftrace_ops_init(ops); |
4f554e95 | 5646 | return ftrace_set_addr(ops, &ip, 1, remove, reset, 1); |
647664ea MH |
5647 | } |
5648 | EXPORT_SYMBOL_GPL(ftrace_set_filter_ip); | |
5649 | ||
4f554e95 JO |
5650 | /** |
5651 | * ftrace_set_filter_ips - set functions to filter on in ftrace by addresses | |
d1530413 RD |
5652 | * @ops: the ops to set the filter with |
5653 | * @ips: the array of addresses to add to or remove from the filter. | |
5654 | * @cnt: the number of addresses in @ips | |
5655 | * @remove: non zero to remove ips from the filter | |
5656 | * @reset: non zero to reset all filters before applying this filter. | |
4f554e95 JO |
5657 | * |
5658 | * Filters denote which functions should be enabled when tracing is enabled | |
5659 | * If @ips array or any ip specified within is NULL , it fails to update filter. | |
8be9fbd5 MR |
5660 | * |
5661 | * This can allocate memory which must be freed before @ops can be freed, | |
5662 | * either by removing each filtered addr or by using | |
5663 | * ftrace_free_filter(@ops). | |
5664 | */ | |
4f554e95 JO |
5665 | int ftrace_set_filter_ips(struct ftrace_ops *ops, unsigned long *ips, |
5666 | unsigned int cnt, int remove, int reset) | |
5667 | { | |
5668 | ftrace_ops_init(ops); | |
5669 | return ftrace_set_addr(ops, ips, cnt, remove, reset, 1); | |
5670 | } | |
5671 | EXPORT_SYMBOL_GPL(ftrace_set_filter_ips); | |
5672 | ||
d032ae89 JF |
5673 | /** |
5674 | * ftrace_ops_set_global_filter - setup ops to use global filters | |
d1530413 | 5675 | * @ops: the ops which will use the global filters |
d032ae89 JF |
5676 | * |
5677 | * ftrace users who need global function trace filtering should call this. | |
5678 | * It can set the global filter only if ops were not initialized before. | |
5679 | */ | |
5680 | void ftrace_ops_set_global_filter(struct ftrace_ops *ops) | |
5681 | { | |
5682 | if (ops->flags & FTRACE_OPS_FL_INITIALIZED) | |
5683 | return; | |
5684 | ||
5685 | ftrace_ops_init(ops); | |
5686 | ops->func_hash = &global_ops.local_hash; | |
5687 | } | |
5688 | EXPORT_SYMBOL_GPL(ftrace_ops_set_global_filter); | |
5689 | ||
647664ea MH |
5690 | static int |
5691 | ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, | |
5692 | int reset, int enable) | |
5693 | { | |
4f554e95 | 5694 | return ftrace_set_hash(ops, buf, len, NULL, 0, 0, reset, enable); |
647664ea MH |
5695 | } |
5696 | ||
77a2b37d SR |
5697 | /** |
5698 | * ftrace_set_filter - set a function to filter on in ftrace | |
d1530413 RD |
5699 | * @ops: the ops to set the filter with |
5700 | * @buf: the string that holds the function filter text. | |
5701 | * @len: the length of the string. | |
5702 | * @reset: non-zero to reset all filters before applying this filter. | |
936e074b SR |
5703 | * |
5704 | * Filters denote which functions should be enabled when tracing is enabled. | |
5705 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
8be9fbd5 MR |
5706 | * |
5707 | * This can allocate memory which must be freed before @ops can be freed, | |
5708 | * either by removing each filtered addr or by using | |
5709 | * ftrace_free_filter(@ops). | |
936e074b | 5710 | */ |
ac483c44 | 5711 | int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, |
936e074b SR |
5712 | int len, int reset) |
5713 | { | |
f04f24fb | 5714 | ftrace_ops_init(ops); |
ac483c44 | 5715 | return ftrace_set_regex(ops, buf, len, reset, 1); |
936e074b SR |
5716 | } |
5717 | EXPORT_SYMBOL_GPL(ftrace_set_filter); | |
5718 | ||
5719 | /** | |
5720 | * ftrace_set_notrace - set a function to not trace in ftrace | |
d1530413 RD |
5721 | * @ops: the ops to set the notrace filter with |
5722 | * @buf: the string that holds the function notrace text. | |
5723 | * @len: the length of the string. | |
5724 | * @reset: non-zero to reset all filters before applying this filter. | |
936e074b SR |
5725 | * |
5726 | * Notrace Filters denote which functions should not be enabled when tracing | |
5727 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
5728 | * for tracing. | |
8be9fbd5 MR |
5729 | * |
5730 | * This can allocate memory which must be freed before @ops can be freed, | |
5731 | * either by removing each filtered addr or by using | |
5732 | * ftrace_free_filter(@ops). | |
936e074b | 5733 | */ |
ac483c44 | 5734 | int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, |
936e074b SR |
5735 | int len, int reset) |
5736 | { | |
f04f24fb | 5737 | ftrace_ops_init(ops); |
ac483c44 | 5738 | return ftrace_set_regex(ops, buf, len, reset, 0); |
936e074b SR |
5739 | } |
5740 | EXPORT_SYMBOL_GPL(ftrace_set_notrace); | |
5741 | /** | |
8d1b065d | 5742 | * ftrace_set_global_filter - set a function to filter on with global tracers |
d1530413 RD |
5743 | * @buf: the string that holds the function filter text. |
5744 | * @len: the length of the string. | |
5745 | * @reset: non-zero to reset all filters before applying this filter. | |
77a2b37d SR |
5746 | * |
5747 | * Filters denote which functions should be enabled when tracing is enabled. | |
5748 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
5749 | */ | |
936e074b | 5750 | void ftrace_set_global_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 5751 | { |
f45948e8 | 5752 | ftrace_set_regex(&global_ops, buf, len, reset, 1); |
41c52c0d | 5753 | } |
936e074b | 5754 | EXPORT_SYMBOL_GPL(ftrace_set_global_filter); |
4eebcc81 | 5755 | |
41c52c0d | 5756 | /** |
8d1b065d | 5757 | * ftrace_set_global_notrace - set a function to not trace with global tracers |
d1530413 RD |
5758 | * @buf: the string that holds the function notrace text. |
5759 | * @len: the length of the string. | |
5760 | * @reset: non-zero to reset all filters before applying this filter. | |
41c52c0d SR |
5761 | * |
5762 | * Notrace Filters denote which functions should not be enabled when tracing | |
5763 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
5764 | * for tracing. | |
5765 | */ | |
936e074b | 5766 | void ftrace_set_global_notrace(unsigned char *buf, int len, int reset) |
41c52c0d | 5767 | { |
f45948e8 | 5768 | ftrace_set_regex(&global_ops, buf, len, reset, 0); |
77a2b37d | 5769 | } |
936e074b | 5770 | EXPORT_SYMBOL_GPL(ftrace_set_global_notrace); |
77a2b37d | 5771 | |
2af15d6a SR |
5772 | /* |
5773 | * command line interface to allow users to set filters on boot up. | |
5774 | */ | |
5775 | #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE | |
5776 | static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata; | |
5777 | static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata; | |
5778 | ||
f1ed7c74 SRRH |
5779 | /* Used by function selftest to not test if filter is set */ |
5780 | bool ftrace_filter_param __initdata; | |
5781 | ||
2af15d6a SR |
5782 | static int __init set_ftrace_notrace(char *str) |
5783 | { | |
f1ed7c74 | 5784 | ftrace_filter_param = true; |
d0c2d66f | 5785 | strscpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE); |
2af15d6a SR |
5786 | return 1; |
5787 | } | |
5788 | __setup("ftrace_notrace=", set_ftrace_notrace); | |
5789 | ||
5790 | static int __init set_ftrace_filter(char *str) | |
5791 | { | |
f1ed7c74 | 5792 | ftrace_filter_param = true; |
d0c2d66f | 5793 | strscpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE); |
2af15d6a SR |
5794 | return 1; |
5795 | } | |
5796 | __setup("ftrace_filter=", set_ftrace_filter); | |
5797 | ||
369bc18f | 5798 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
f6060f46 | 5799 | static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata; |
0d7d9a16 | 5800 | static char ftrace_graph_notrace_buf[FTRACE_FILTER_SIZE] __initdata; |
b9b0c831 | 5801 | static int ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer); |
801c29fd | 5802 | |
369bc18f SA |
5803 | static int __init set_graph_function(char *str) |
5804 | { | |
d0c2d66f | 5805 | strscpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE); |
369bc18f SA |
5806 | return 1; |
5807 | } | |
5808 | __setup("ftrace_graph_filter=", set_graph_function); | |
5809 | ||
0d7d9a16 NK |
5810 | static int __init set_graph_notrace_function(char *str) |
5811 | { | |
d0c2d66f | 5812 | strscpy(ftrace_graph_notrace_buf, str, FTRACE_FILTER_SIZE); |
0d7d9a16 NK |
5813 | return 1; |
5814 | } | |
5815 | __setup("ftrace_graph_notrace=", set_graph_notrace_function); | |
5816 | ||
65a50c65 TB |
5817 | static int __init set_graph_max_depth_function(char *str) |
5818 | { | |
5819 | if (!str) | |
5820 | return 0; | |
5821 | fgraph_max_depth = simple_strtoul(str, NULL, 0); | |
5822 | return 1; | |
5823 | } | |
5824 | __setup("ftrace_graph_max_depth=", set_graph_max_depth_function); | |
0d7d9a16 NK |
5825 | |
5826 | static void __init set_ftrace_early_graph(char *buf, int enable) | |
369bc18f SA |
5827 | { |
5828 | int ret; | |
5829 | char *func; | |
b9b0c831 | 5830 | struct ftrace_hash *hash; |
0d7d9a16 | 5831 | |
92ad18ec | 5832 | hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS); |
24589e3a | 5833 | if (MEM_FAIL(!hash, "Failed to allocate hash\n")) |
92ad18ec | 5834 | return; |
369bc18f SA |
5835 | |
5836 | while (buf) { | |
5837 | func = strsep(&buf, ","); | |
5838 | /* we allow only one expression at a time */ | |
b9b0c831 | 5839 | ret = ftrace_graph_set_hash(hash, func); |
369bc18f SA |
5840 | if (ret) |
5841 | printk(KERN_DEBUG "ftrace: function %s not " | |
5842 | "traceable\n", func); | |
5843 | } | |
92ad18ec SRV |
5844 | |
5845 | if (enable) | |
5846 | ftrace_graph_hash = hash; | |
5847 | else | |
5848 | ftrace_graph_notrace_hash = hash; | |
369bc18f SA |
5849 | } |
5850 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
5851 | ||
2a85a37f SR |
5852 | void __init |
5853 | ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable) | |
2af15d6a SR |
5854 | { |
5855 | char *func; | |
5856 | ||
f04f24fb MH |
5857 | ftrace_ops_init(ops); |
5858 | ||
2af15d6a SR |
5859 | while (buf) { |
5860 | func = strsep(&buf, ","); | |
f45948e8 | 5861 | ftrace_set_regex(ops, func, strlen(func), 0, enable); |
2af15d6a SR |
5862 | } |
5863 | } | |
5864 | ||
5865 | static void __init set_ftrace_early_filters(void) | |
5866 | { | |
5867 | if (ftrace_filter_buf[0]) | |
2a85a37f | 5868 | ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1); |
2af15d6a | 5869 | if (ftrace_notrace_buf[0]) |
2a85a37f | 5870 | ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0); |
369bc18f SA |
5871 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
5872 | if (ftrace_graph_buf[0]) | |
0d7d9a16 NK |
5873 | set_ftrace_early_graph(ftrace_graph_buf, 1); |
5874 | if (ftrace_graph_notrace_buf[0]) | |
5875 | set_ftrace_early_graph(ftrace_graph_notrace_buf, 0); | |
369bc18f | 5876 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
2af15d6a SR |
5877 | } |
5878 | ||
fc13cb0c | 5879 | int ftrace_regex_release(struct inode *inode, struct file *file) |
5072c59f SR |
5880 | { |
5881 | struct seq_file *m = (struct seq_file *)file->private_data; | |
5882 | struct ftrace_iterator *iter; | |
33dc9b12 | 5883 | struct ftrace_hash **orig_hash; |
689fd8b6 | 5884 | struct trace_parser *parser; |
ed926f9b | 5885 | int filter_hash; |
5072c59f | 5886 | |
5072c59f SR |
5887 | if (file->f_mode & FMODE_READ) { |
5888 | iter = m->private; | |
5072c59f SR |
5889 | seq_release(inode, file); |
5890 | } else | |
5891 | iter = file->private_data; | |
5892 | ||
689fd8b6 | 5893 | parser = &iter->parser; |
5894 | if (trace_parser_loaded(parser)) { | |
8c9af478 SRV |
5895 | int enable = !(iter->flags & FTRACE_ITER_NOTRACE); |
5896 | ||
5897 | ftrace_process_regex(iter, parser->buffer, | |
5898 | parser->idx, enable); | |
5072c59f SR |
5899 | } |
5900 | ||
689fd8b6 | 5901 | trace_parser_put(parser); |
689fd8b6 | 5902 | |
33b7f99c | 5903 | mutex_lock(&iter->ops->func_hash->regex_lock); |
3f2367ba | 5904 | |
058e297d | 5905 | if (file->f_mode & FMODE_WRITE) { |
ed926f9b SR |
5906 | filter_hash = !!(iter->flags & FTRACE_ITER_FILTER); |
5907 | ||
8c08f0d5 | 5908 | if (filter_hash) { |
33b7f99c | 5909 | orig_hash = &iter->ops->func_hash->filter_hash; |
0ce0638e ZY |
5910 | if (iter->tr) { |
5911 | if (list_empty(&iter->tr->mod_trace)) | |
5912 | iter->hash->flags &= ~FTRACE_HASH_FL_MOD; | |
5913 | else | |
5914 | iter->hash->flags |= FTRACE_HASH_FL_MOD; | |
5915 | } | |
8c08f0d5 | 5916 | } else |
33b7f99c | 5917 | orig_hash = &iter->ops->func_hash->notrace_hash; |
33dc9b12 | 5918 | |
058e297d | 5919 | mutex_lock(&ftrace_lock); |
045e269c | 5920 | ftrace_hash_move_and_update_ops(iter->ops, orig_hash, |
e16b35dd | 5921 | iter->hash, filter_hash); |
058e297d | 5922 | mutex_unlock(&ftrace_lock); |
c20489da SRV |
5923 | } else { |
5924 | /* For read only, the hash is the ops hash */ | |
5925 | iter->hash = NULL; | |
058e297d | 5926 | } |
3f2367ba | 5927 | |
33b7f99c | 5928 | mutex_unlock(&iter->ops->func_hash->regex_lock); |
33dc9b12 | 5929 | free_ftrace_hash(iter->hash); |
9ef16693 SRV |
5930 | if (iter->tr) |
5931 | trace_array_put(iter->tr); | |
33dc9b12 | 5932 | kfree(iter); |
058e297d | 5933 | |
5072c59f SR |
5934 | return 0; |
5935 | } | |
5936 | ||
5e2336a0 | 5937 | static const struct file_operations ftrace_avail_fops = { |
5072c59f SR |
5938 | .open = ftrace_avail_open, |
5939 | .read = seq_read, | |
5940 | .llseek = seq_lseek, | |
3be04b47 | 5941 | .release = seq_release_private, |
5072c59f SR |
5942 | }; |
5943 | ||
647bcd03 SR |
5944 | static const struct file_operations ftrace_enabled_fops = { |
5945 | .open = ftrace_enabled_open, | |
5946 | .read = seq_read, | |
5947 | .llseek = seq_lseek, | |
5948 | .release = seq_release_private, | |
5949 | }; | |
5950 | ||
e11b521a SRG |
5951 | static const struct file_operations ftrace_touched_fops = { |
5952 | .open = ftrace_touched_open, | |
5953 | .read = seq_read, | |
5954 | .llseek = seq_lseek, | |
5955 | .release = seq_release_private, | |
5956 | }; | |
5957 | ||
83f74441 JO |
5958 | static const struct file_operations ftrace_avail_addrs_fops = { |
5959 | .open = ftrace_avail_addrs_open, | |
5960 | .read = seq_read, | |
5961 | .llseek = seq_lseek, | |
5962 | .release = seq_release_private, | |
5963 | }; | |
5964 | ||
5e2336a0 | 5965 | static const struct file_operations ftrace_filter_fops = { |
5072c59f | 5966 | .open = ftrace_filter_open, |
850a80cf | 5967 | .read = seq_read, |
5072c59f | 5968 | .write = ftrace_filter_write, |
098c879e | 5969 | .llseek = tracing_lseek, |
1cf41dd7 | 5970 | .release = ftrace_regex_release, |
5072c59f SR |
5971 | }; |
5972 | ||
5e2336a0 | 5973 | static const struct file_operations ftrace_notrace_fops = { |
41c52c0d | 5974 | .open = ftrace_notrace_open, |
850a80cf | 5975 | .read = seq_read, |
41c52c0d | 5976 | .write = ftrace_notrace_write, |
098c879e | 5977 | .llseek = tracing_lseek, |
1cf41dd7 | 5978 | .release = ftrace_regex_release, |
41c52c0d SR |
5979 | }; |
5980 | ||
ea4e2bc4 SR |
5981 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
5982 | ||
5983 | static DEFINE_MUTEX(graph_lock); | |
5984 | ||
24a9729f | 5985 | struct ftrace_hash __rcu *ftrace_graph_hash = EMPTY_HASH; |
fd0e6852 | 5986 | struct ftrace_hash __rcu *ftrace_graph_notrace_hash = EMPTY_HASH; |
b9b0c831 NK |
5987 | |
5988 | enum graph_filter_type { | |
5989 | GRAPH_FILTER_NOTRACE = 0, | |
5990 | GRAPH_FILTER_FUNCTION, | |
5991 | }; | |
ea4e2bc4 | 5992 | |
555fc781 SRV |
5993 | #define FTRACE_GRAPH_EMPTY ((void *)1) |
5994 | ||
faf982a6 | 5995 | struct ftrace_graph_data { |
e704eff3 SRV |
5996 | struct ftrace_hash *hash; |
5997 | struct ftrace_func_entry *entry; | |
5998 | int idx; /* for hash table iteration */ | |
5999 | enum graph_filter_type type; | |
6000 | struct ftrace_hash *new_hash; | |
6001 | const struct seq_operations *seq_ops; | |
6002 | struct trace_parser parser; | |
faf982a6 NK |
6003 | }; |
6004 | ||
ea4e2bc4 | 6005 | static void * |
85951842 | 6006 | __g_next(struct seq_file *m, loff_t *pos) |
ea4e2bc4 | 6007 | { |
faf982a6 | 6008 | struct ftrace_graph_data *fgd = m->private; |
b9b0c831 NK |
6009 | struct ftrace_func_entry *entry = fgd->entry; |
6010 | struct hlist_head *head; | |
6011 | int i, idx = fgd->idx; | |
faf982a6 | 6012 | |
b9b0c831 | 6013 | if (*pos >= fgd->hash->count) |
ea4e2bc4 | 6014 | return NULL; |
b9b0c831 NK |
6015 | |
6016 | if (entry) { | |
6017 | hlist_for_each_entry_continue(entry, hlist) { | |
6018 | fgd->entry = entry; | |
6019 | return entry; | |
6020 | } | |
6021 | ||
6022 | idx++; | |
6023 | } | |
6024 | ||
6025 | for (i = idx; i < 1 << fgd->hash->size_bits; i++) { | |
6026 | head = &fgd->hash->buckets[i]; | |
6027 | hlist_for_each_entry(entry, head, hlist) { | |
6028 | fgd->entry = entry; | |
6029 | fgd->idx = i; | |
6030 | return entry; | |
6031 | } | |
6032 | } | |
6033 | return NULL; | |
85951842 | 6034 | } |
ea4e2bc4 | 6035 | |
85951842 LZ |
6036 | static void * |
6037 | g_next(struct seq_file *m, void *v, loff_t *pos) | |
6038 | { | |
6039 | (*pos)++; | |
6040 | return __g_next(m, pos); | |
ea4e2bc4 SR |
6041 | } |
6042 | ||
6043 | static void *g_start(struct seq_file *m, loff_t *pos) | |
6044 | { | |
faf982a6 NK |
6045 | struct ftrace_graph_data *fgd = m->private; |
6046 | ||
ea4e2bc4 SR |
6047 | mutex_lock(&graph_lock); |
6048 | ||
649b988b SRV |
6049 | if (fgd->type == GRAPH_FILTER_FUNCTION) |
6050 | fgd->hash = rcu_dereference_protected(ftrace_graph_hash, | |
6051 | lockdep_is_held(&graph_lock)); | |
6052 | else | |
6053 | fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash, | |
6054 | lockdep_is_held(&graph_lock)); | |
6055 | ||
f9349a8f | 6056 | /* Nothing, tell g_show to print all functions are enabled */ |
b9b0c831 | 6057 | if (ftrace_hash_empty(fgd->hash) && !*pos) |
555fc781 | 6058 | return FTRACE_GRAPH_EMPTY; |
f9349a8f | 6059 | |
b9b0c831 NK |
6060 | fgd->idx = 0; |
6061 | fgd->entry = NULL; | |
85951842 | 6062 | return __g_next(m, pos); |
ea4e2bc4 SR |
6063 | } |
6064 | ||
6065 | static void g_stop(struct seq_file *m, void *p) | |
6066 | { | |
6067 | mutex_unlock(&graph_lock); | |
6068 | } | |
6069 | ||
6070 | static int g_show(struct seq_file *m, void *v) | |
6071 | { | |
b9b0c831 | 6072 | struct ftrace_func_entry *entry = v; |
ea4e2bc4 | 6073 | |
b9b0c831 | 6074 | if (!entry) |
ea4e2bc4 SR |
6075 | return 0; |
6076 | ||
555fc781 | 6077 | if (entry == FTRACE_GRAPH_EMPTY) { |
280d1429 NK |
6078 | struct ftrace_graph_data *fgd = m->private; |
6079 | ||
b9b0c831 | 6080 | if (fgd->type == GRAPH_FILTER_FUNCTION) |
fa6f0cc7 | 6081 | seq_puts(m, "#### all functions enabled ####\n"); |
280d1429 | 6082 | else |
fa6f0cc7 | 6083 | seq_puts(m, "#### no functions disabled ####\n"); |
f9349a8f FW |
6084 | return 0; |
6085 | } | |
6086 | ||
b9b0c831 | 6087 | seq_printf(m, "%ps\n", (void *)entry->ip); |
ea4e2bc4 SR |
6088 | |
6089 | return 0; | |
6090 | } | |
6091 | ||
88e9d34c | 6092 | static const struct seq_operations ftrace_graph_seq_ops = { |
ea4e2bc4 SR |
6093 | .start = g_start, |
6094 | .next = g_next, | |
6095 | .stop = g_stop, | |
6096 | .show = g_show, | |
6097 | }; | |
6098 | ||
6099 | static int | |
faf982a6 NK |
6100 | __ftrace_graph_open(struct inode *inode, struct file *file, |
6101 | struct ftrace_graph_data *fgd) | |
ea4e2bc4 | 6102 | { |
17911ff3 | 6103 | int ret; |
b9b0c831 | 6104 | struct ftrace_hash *new_hash = NULL; |
ea4e2bc4 | 6105 | |
17911ff3 SRV |
6106 | ret = security_locked_down(LOCKDOWN_TRACEFS); |
6107 | if (ret) | |
6108 | return ret; | |
6109 | ||
b9b0c831 NK |
6110 | if (file->f_mode & FMODE_WRITE) { |
6111 | const int size_bits = FTRACE_HASH_DEFAULT_BITS; | |
6112 | ||
e704eff3 SRV |
6113 | if (trace_parser_get_init(&fgd->parser, FTRACE_BUFF_MAX)) |
6114 | return -ENOMEM; | |
6115 | ||
b9b0c831 NK |
6116 | if (file->f_flags & O_TRUNC) |
6117 | new_hash = alloc_ftrace_hash(size_bits); | |
6118 | else | |
6119 | new_hash = alloc_and_copy_ftrace_hash(size_bits, | |
6120 | fgd->hash); | |
6121 | if (!new_hash) { | |
6122 | ret = -ENOMEM; | |
6123 | goto out; | |
6124 | } | |
ea4e2bc4 SR |
6125 | } |
6126 | ||
faf982a6 | 6127 | if (file->f_mode & FMODE_READ) { |
b9b0c831 | 6128 | ret = seq_open(file, &ftrace_graph_seq_ops); |
faf982a6 NK |
6129 | if (!ret) { |
6130 | struct seq_file *m = file->private_data; | |
6131 | m->private = fgd; | |
b9b0c831 NK |
6132 | } else { |
6133 | /* Failed */ | |
6134 | free_ftrace_hash(new_hash); | |
6135 | new_hash = NULL; | |
faf982a6 NK |
6136 | } |
6137 | } else | |
6138 | file->private_data = fgd; | |
ea4e2bc4 | 6139 | |
b9b0c831 | 6140 | out: |
e704eff3 SRV |
6141 | if (ret < 0 && file->f_mode & FMODE_WRITE) |
6142 | trace_parser_put(&fgd->parser); | |
6143 | ||
b9b0c831 | 6144 | fgd->new_hash = new_hash; |
649b988b SRV |
6145 | |
6146 | /* | |
6147 | * All uses of fgd->hash must be taken with the graph_lock | |
6148 | * held. The graph_lock is going to be released, so force | |
6149 | * fgd->hash to be reinitialized when it is taken again. | |
6150 | */ | |
6151 | fgd->hash = NULL; | |
6152 | ||
ea4e2bc4 SR |
6153 | return ret; |
6154 | } | |
6155 | ||
faf982a6 NK |
6156 | static int |
6157 | ftrace_graph_open(struct inode *inode, struct file *file) | |
6158 | { | |
6159 | struct ftrace_graph_data *fgd; | |
b9b0c831 | 6160 | int ret; |
faf982a6 NK |
6161 | |
6162 | if (unlikely(ftrace_disabled)) | |
6163 | return -ENODEV; | |
6164 | ||
6165 | fgd = kmalloc(sizeof(*fgd), GFP_KERNEL); | |
6166 | if (fgd == NULL) | |
6167 | return -ENOMEM; | |
6168 | ||
b9b0c831 NK |
6169 | mutex_lock(&graph_lock); |
6170 | ||
649b988b SRV |
6171 | fgd->hash = rcu_dereference_protected(ftrace_graph_hash, |
6172 | lockdep_is_held(&graph_lock)); | |
b9b0c831 | 6173 | fgd->type = GRAPH_FILTER_FUNCTION; |
faf982a6 NK |
6174 | fgd->seq_ops = &ftrace_graph_seq_ops; |
6175 | ||
b9b0c831 NK |
6176 | ret = __ftrace_graph_open(inode, file, fgd); |
6177 | if (ret < 0) | |
6178 | kfree(fgd); | |
6179 | ||
6180 | mutex_unlock(&graph_lock); | |
6181 | return ret; | |
faf982a6 NK |
6182 | } |
6183 | ||
29ad23b0 NK |
6184 | static int |
6185 | ftrace_graph_notrace_open(struct inode *inode, struct file *file) | |
6186 | { | |
6187 | struct ftrace_graph_data *fgd; | |
b9b0c831 | 6188 | int ret; |
29ad23b0 NK |
6189 | |
6190 | if (unlikely(ftrace_disabled)) | |
6191 | return -ENODEV; | |
6192 | ||
6193 | fgd = kmalloc(sizeof(*fgd), GFP_KERNEL); | |
6194 | if (fgd == NULL) | |
6195 | return -ENOMEM; | |
6196 | ||
b9b0c831 NK |
6197 | mutex_lock(&graph_lock); |
6198 | ||
649b988b SRV |
6199 | fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash, |
6200 | lockdep_is_held(&graph_lock)); | |
b9b0c831 | 6201 | fgd->type = GRAPH_FILTER_NOTRACE; |
29ad23b0 NK |
6202 | fgd->seq_ops = &ftrace_graph_seq_ops; |
6203 | ||
b9b0c831 NK |
6204 | ret = __ftrace_graph_open(inode, file, fgd); |
6205 | if (ret < 0) | |
6206 | kfree(fgd); | |
6207 | ||
6208 | mutex_unlock(&graph_lock); | |
6209 | return ret; | |
29ad23b0 NK |
6210 | } |
6211 | ||
87827111 LZ |
6212 | static int |
6213 | ftrace_graph_release(struct inode *inode, struct file *file) | |
6214 | { | |
b9b0c831 | 6215 | struct ftrace_graph_data *fgd; |
e704eff3 SRV |
6216 | struct ftrace_hash *old_hash, *new_hash; |
6217 | struct trace_parser *parser; | |
6218 | int ret = 0; | |
b9b0c831 | 6219 | |
faf982a6 NK |
6220 | if (file->f_mode & FMODE_READ) { |
6221 | struct seq_file *m = file->private_data; | |
6222 | ||
b9b0c831 | 6223 | fgd = m->private; |
87827111 | 6224 | seq_release(inode, file); |
faf982a6 | 6225 | } else { |
b9b0c831 | 6226 | fgd = file->private_data; |
faf982a6 NK |
6227 | } |
6228 | ||
e704eff3 SRV |
6229 | |
6230 | if (file->f_mode & FMODE_WRITE) { | |
6231 | ||
6232 | parser = &fgd->parser; | |
6233 | ||
6234 | if (trace_parser_loaded((parser))) { | |
e704eff3 SRV |
6235 | ret = ftrace_graph_set_hash(fgd->new_hash, |
6236 | parser->buffer); | |
6237 | } | |
6238 | ||
6239 | trace_parser_put(parser); | |
6240 | ||
6241 | new_hash = __ftrace_hash_move(fgd->new_hash); | |
6242 | if (!new_hash) { | |
6243 | ret = -ENOMEM; | |
6244 | goto out; | |
6245 | } | |
6246 | ||
6247 | mutex_lock(&graph_lock); | |
6248 | ||
6249 | if (fgd->type == GRAPH_FILTER_FUNCTION) { | |
6250 | old_hash = rcu_dereference_protected(ftrace_graph_hash, | |
6251 | lockdep_is_held(&graph_lock)); | |
6252 | rcu_assign_pointer(ftrace_graph_hash, new_hash); | |
6253 | } else { | |
6254 | old_hash = rcu_dereference_protected(ftrace_graph_notrace_hash, | |
6255 | lockdep_is_held(&graph_lock)); | |
6256 | rcu_assign_pointer(ftrace_graph_notrace_hash, new_hash); | |
6257 | } | |
6258 | ||
6259 | mutex_unlock(&graph_lock); | |
6260 | ||
54a16ff6 SRV |
6261 | /* |
6262 | * We need to do a hard force of sched synchronization. | |
6263 | * This is because we use preempt_disable() to do RCU, but | |
6264 | * the function tracers can be called where RCU is not watching | |
6265 | * (like before user_exit()). We can not rely on the RCU | |
6266 | * infrastructure to do the synchronization, thus we must do it | |
6267 | * ourselves. | |
6268 | */ | |
68e83498 NSJ |
6269 | if (old_hash != EMPTY_HASH) |
6270 | synchronize_rcu_tasks_rude(); | |
e704eff3 SRV |
6271 | |
6272 | free_ftrace_hash(old_hash); | |
6273 | } | |
6274 | ||
6275 | out: | |
f9797c2f | 6276 | free_ftrace_hash(fgd->new_hash); |
b9b0c831 NK |
6277 | kfree(fgd); |
6278 | ||
e704eff3 | 6279 | return ret; |
87827111 LZ |
6280 | } |
6281 | ||
ea4e2bc4 | 6282 | static int |
b9b0c831 | 6283 | ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer) |
ea4e2bc4 | 6284 | { |
3ba00929 | 6285 | struct ftrace_glob func_g; |
ea4e2bc4 SR |
6286 | struct dyn_ftrace *rec; |
6287 | struct ftrace_page *pg; | |
b9b0c831 | 6288 | struct ftrace_func_entry *entry; |
c7c6b1fe | 6289 | int fail = 1; |
3ba00929 | 6290 | int not; |
ea4e2bc4 | 6291 | |
f9349a8f | 6292 | /* decode regex */ |
3ba00929 DS |
6293 | func_g.type = filter_parse_regex(buffer, strlen(buffer), |
6294 | &func_g.search, ¬); | |
f9349a8f | 6295 | |
3ba00929 | 6296 | func_g.len = strlen(func_g.search); |
f9349a8f | 6297 | |
52baf119 | 6298 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
6299 | |
6300 | if (unlikely(ftrace_disabled)) { | |
6301 | mutex_unlock(&ftrace_lock); | |
6302 | return -ENODEV; | |
6303 | } | |
6304 | ||
265c831c SR |
6305 | do_for_each_ftrace_rec(pg, rec) { |
6306 | ||
546fece4 SRRH |
6307 | if (rec->flags & FTRACE_FL_DISABLED) |
6308 | continue; | |
6309 | ||
0b507e1e | 6310 | if (ftrace_match_record(rec, &func_g, NULL, 0)) { |
b9b0c831 | 6311 | entry = ftrace_lookup_ip(hash, rec->ip); |
c7c6b1fe LZ |
6312 | |
6313 | if (!not) { | |
6314 | fail = 0; | |
b9b0c831 NK |
6315 | |
6316 | if (entry) | |
6317 | continue; | |
d05cb470 | 6318 | if (add_hash_entry(hash, rec->ip) == NULL) |
b9b0c831 | 6319 | goto out; |
c7c6b1fe | 6320 | } else { |
b9b0c831 NK |
6321 | if (entry) { |
6322 | free_hash_entry(hash, entry); | |
c7c6b1fe LZ |
6323 | fail = 0; |
6324 | } | |
6325 | } | |
ea4e2bc4 | 6326 | } |
265c831c | 6327 | } while_for_each_ftrace_rec(); |
c7c6b1fe | 6328 | out: |
52baf119 | 6329 | mutex_unlock(&ftrace_lock); |
ea4e2bc4 | 6330 | |
c7c6b1fe LZ |
6331 | if (fail) |
6332 | return -EINVAL; | |
6333 | ||
c7c6b1fe | 6334 | return 0; |
ea4e2bc4 SR |
6335 | } |
6336 | ||
6337 | static ssize_t | |
6338 | ftrace_graph_write(struct file *file, const char __user *ubuf, | |
6339 | size_t cnt, loff_t *ppos) | |
6340 | { | |
6a10108b | 6341 | ssize_t read, ret = 0; |
faf982a6 | 6342 | struct ftrace_graph_data *fgd = file->private_data; |
e704eff3 | 6343 | struct trace_parser *parser; |
ea4e2bc4 | 6344 | |
c7c6b1fe | 6345 | if (!cnt) |
ea4e2bc4 SR |
6346 | return 0; |
6347 | ||
ae98d27a SRV |
6348 | /* Read mode uses seq functions */ |
6349 | if (file->f_mode & FMODE_READ) { | |
6350 | struct seq_file *m = file->private_data; | |
6351 | fgd = m->private; | |
6352 | } | |
6353 | ||
e704eff3 | 6354 | parser = &fgd->parser; |
ea4e2bc4 | 6355 | |
e704eff3 | 6356 | read = trace_get_user(parser, ubuf, cnt, ppos); |
689fd8b6 | 6357 | |
e704eff3 SRV |
6358 | if (read >= 0 && trace_parser_loaded(parser) && |
6359 | !trace_parser_cont(parser)) { | |
6a10108b | 6360 | |
b9b0c831 | 6361 | ret = ftrace_graph_set_hash(fgd->new_hash, |
e704eff3 SRV |
6362 | parser->buffer); |
6363 | trace_parser_clear(parser); | |
ea4e2bc4 | 6364 | } |
ea4e2bc4 | 6365 | |
6a10108b NK |
6366 | if (!ret) |
6367 | ret = read; | |
1eb90f13 | 6368 | |
ea4e2bc4 SR |
6369 | return ret; |
6370 | } | |
6371 | ||
6372 | static const struct file_operations ftrace_graph_fops = { | |
87827111 LZ |
6373 | .open = ftrace_graph_open, |
6374 | .read = seq_read, | |
6375 | .write = ftrace_graph_write, | |
098c879e | 6376 | .llseek = tracing_lseek, |
87827111 | 6377 | .release = ftrace_graph_release, |
ea4e2bc4 | 6378 | }; |
29ad23b0 NK |
6379 | |
6380 | static const struct file_operations ftrace_graph_notrace_fops = { | |
6381 | .open = ftrace_graph_notrace_open, | |
6382 | .read = seq_read, | |
6383 | .write = ftrace_graph_write, | |
098c879e | 6384 | .llseek = tracing_lseek, |
29ad23b0 NK |
6385 | .release = ftrace_graph_release, |
6386 | }; | |
ea4e2bc4 SR |
6387 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
6388 | ||
591dffda SRRH |
6389 | void ftrace_create_filter_files(struct ftrace_ops *ops, |
6390 | struct dentry *parent) | |
6391 | { | |
6392 | ||
21ccc9cd | 6393 | trace_create_file("set_ftrace_filter", TRACE_MODE_WRITE, parent, |
591dffda SRRH |
6394 | ops, &ftrace_filter_fops); |
6395 | ||
21ccc9cd | 6396 | trace_create_file("set_ftrace_notrace", TRACE_MODE_WRITE, parent, |
591dffda SRRH |
6397 | ops, &ftrace_notrace_fops); |
6398 | } | |
6399 | ||
6400 | /* | |
6401 | * The name "destroy_filter_files" is really a misnomer. Although | |
9efb85c5 | 6402 | * in the future, it may actually delete the files, but this is |
591dffda SRRH |
6403 | * really intended to make sure the ops passed in are disabled |
6404 | * and that when this function returns, the caller is free to | |
6405 | * free the ops. | |
6406 | * | |
6407 | * The "destroy" name is only to match the "create" name that this | |
6408 | * should be paired with. | |
6409 | */ | |
6410 | void ftrace_destroy_filter_files(struct ftrace_ops *ops) | |
6411 | { | |
6412 | mutex_lock(&ftrace_lock); | |
6413 | if (ops->flags & FTRACE_OPS_FL_ENABLED) | |
6414 | ftrace_shutdown(ops, 0); | |
6415 | ops->flags |= FTRACE_OPS_FL_DELETED; | |
2840f84f | 6416 | ftrace_free_filter(ops); |
591dffda SRRH |
6417 | mutex_unlock(&ftrace_lock); |
6418 | } | |
6419 | ||
8434dc93 | 6420 | static __init int ftrace_init_dyn_tracefs(struct dentry *d_tracer) |
5072c59f | 6421 | { |
5072c59f | 6422 | |
21ccc9cd | 6423 | trace_create_file("available_filter_functions", TRACE_MODE_READ, |
5452af66 | 6424 | d_tracer, NULL, &ftrace_avail_fops); |
5072c59f | 6425 | |
83f74441 JO |
6426 | trace_create_file("available_filter_functions_addrs", TRACE_MODE_READ, |
6427 | d_tracer, NULL, &ftrace_avail_addrs_fops); | |
6428 | ||
21ccc9cd | 6429 | trace_create_file("enabled_functions", TRACE_MODE_READ, |
647bcd03 SR |
6430 | d_tracer, NULL, &ftrace_enabled_fops); |
6431 | ||
e11b521a SRG |
6432 | trace_create_file("touched_functions", TRACE_MODE_READ, |
6433 | d_tracer, NULL, &ftrace_touched_fops); | |
6434 | ||
591dffda | 6435 | ftrace_create_filter_files(&global_ops, d_tracer); |
ad90c0e3 | 6436 | |
ea4e2bc4 | 6437 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
21ccc9cd | 6438 | trace_create_file("set_graph_function", TRACE_MODE_WRITE, d_tracer, |
ea4e2bc4 SR |
6439 | NULL, |
6440 | &ftrace_graph_fops); | |
21ccc9cd | 6441 | trace_create_file("set_graph_notrace", TRACE_MODE_WRITE, d_tracer, |
29ad23b0 NK |
6442 | NULL, |
6443 | &ftrace_graph_notrace_fops); | |
ea4e2bc4 SR |
6444 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
6445 | ||
5072c59f SR |
6446 | return 0; |
6447 | } | |
6448 | ||
9fd49328 | 6449 | static int ftrace_cmp_ips(const void *a, const void *b) |
68950619 | 6450 | { |
9fd49328 SR |
6451 | const unsigned long *ipa = a; |
6452 | const unsigned long *ipb = b; | |
68950619 | 6453 | |
9fd49328 SR |
6454 | if (*ipa > *ipb) |
6455 | return 1; | |
6456 | if (*ipa < *ipb) | |
6457 | return -1; | |
6458 | return 0; | |
6459 | } | |
6460 | ||
8147dc78 SRV |
6461 | #ifdef CONFIG_FTRACE_SORT_STARTUP_TEST |
6462 | static void test_is_sorted(unsigned long *start, unsigned long count) | |
6463 | { | |
6464 | int i; | |
6465 | ||
6466 | for (i = 1; i < count; i++) { | |
6467 | if (WARN(start[i - 1] > start[i], | |
6468 | "[%d] %pS at %lx is not sorted with %pS at %lx\n", i, | |
6469 | (void *)start[i - 1], start[i - 1], | |
6470 | (void *)start[i], start[i])) | |
6471 | break; | |
6472 | } | |
6473 | if (i == count) | |
6474 | pr_info("ftrace section at %px sorted properly\n", start); | |
6475 | } | |
6476 | #else | |
6477 | static void test_is_sorted(unsigned long *start, unsigned long count) | |
6478 | { | |
6479 | } | |
6480 | #endif | |
6481 | ||
5cb084bb | 6482 | static int ftrace_process_locs(struct module *mod, |
31e88909 | 6483 | unsigned long *start, |
68bf21aa SR |
6484 | unsigned long *end) |
6485 | { | |
26efd79c | 6486 | struct ftrace_page *pg_unuse = NULL; |
706c81f8 | 6487 | struct ftrace_page *start_pg; |
a7900875 | 6488 | struct ftrace_page *pg; |
706c81f8 | 6489 | struct dyn_ftrace *rec; |
26efd79c | 6490 | unsigned long skipped = 0; |
a7900875 | 6491 | unsigned long count; |
68bf21aa SR |
6492 | unsigned long *p; |
6493 | unsigned long addr; | |
4376cac6 | 6494 | unsigned long flags = 0; /* Shut up gcc */ |
a7900875 SR |
6495 | int ret = -ENOMEM; |
6496 | ||
6497 | count = end - start; | |
6498 | ||
6499 | if (!count) | |
6500 | return 0; | |
6501 | ||
72b3942a YL |
6502 | /* |
6503 | * Sorting mcount in vmlinux at build time depend on | |
6b9b6413 | 6504 | * CONFIG_BUILDTIME_MCOUNT_SORT, while mcount loc in |
72b3942a YL |
6505 | * modules can not be sorted at build time. |
6506 | */ | |
6b9b6413 | 6507 | if (!IS_ENABLED(CONFIG_BUILDTIME_MCOUNT_SORT) || mod) { |
72b3942a YL |
6508 | sort(start, count, sizeof(*start), |
6509 | ftrace_cmp_ips, NULL); | |
8147dc78 SRV |
6510 | } else { |
6511 | test_is_sorted(start, count); | |
72b3942a | 6512 | } |
9fd49328 | 6513 | |
706c81f8 SR |
6514 | start_pg = ftrace_allocate_pages(count); |
6515 | if (!start_pg) | |
a7900875 | 6516 | return -ENOMEM; |
68bf21aa | 6517 | |
e6ea44e9 | 6518 | mutex_lock(&ftrace_lock); |
a7900875 | 6519 | |
32082309 SR |
6520 | /* |
6521 | * Core and each module needs their own pages, as | |
6522 | * modules will free them when they are removed. | |
6523 | * Force a new page to be allocated for modules. | |
6524 | */ | |
a7900875 SR |
6525 | if (!mod) { |
6526 | WARN_ON(ftrace_pages || ftrace_pages_start); | |
6527 | /* First initialization */ | |
706c81f8 | 6528 | ftrace_pages = ftrace_pages_start = start_pg; |
a7900875 | 6529 | } else { |
32082309 | 6530 | if (!ftrace_pages) |
a7900875 | 6531 | goto out; |
32082309 | 6532 | |
a7900875 SR |
6533 | if (WARN_ON(ftrace_pages->next)) { |
6534 | /* Hmm, we have free pages? */ | |
6535 | while (ftrace_pages->next) | |
6536 | ftrace_pages = ftrace_pages->next; | |
32082309 | 6537 | } |
a7900875 | 6538 | |
706c81f8 | 6539 | ftrace_pages->next = start_pg; |
32082309 SR |
6540 | } |
6541 | ||
68bf21aa | 6542 | p = start; |
706c81f8 | 6543 | pg = start_pg; |
68bf21aa | 6544 | while (p < end) { |
db42523b | 6545 | unsigned long end_offset; |
68bf21aa | 6546 | addr = ftrace_call_adjust(*p++); |
20e5227e SR |
6547 | /* |
6548 | * Some architecture linkers will pad between | |
6549 | * the different mcount_loc sections of different | |
6550 | * object files to satisfy alignments. | |
6551 | * Skip any NULL pointers. | |
6552 | */ | |
26efd79c ZY |
6553 | if (!addr) { |
6554 | skipped++; | |
20e5227e | 6555 | continue; |
26efd79c | 6556 | } |
706c81f8 | 6557 | |
db42523b LT |
6558 | end_offset = (pg->index+1) * sizeof(pg->records[0]); |
6559 | if (end_offset > PAGE_SIZE << pg->order) { | |
706c81f8 SR |
6560 | /* We should have allocated enough */ |
6561 | if (WARN_ON(!pg->next)) | |
6562 | break; | |
6563 | pg = pg->next; | |
6564 | } | |
6565 | ||
6566 | rec = &pg->records[pg->index++]; | |
6567 | rec->ip = addr; | |
68bf21aa SR |
6568 | } |
6569 | ||
26efd79c ZY |
6570 | if (pg->next) { |
6571 | pg_unuse = pg->next; | |
6572 | pg->next = NULL; | |
6573 | } | |
706c81f8 SR |
6574 | |
6575 | /* Assign the last page to ftrace_pages */ | |
6576 | ftrace_pages = pg; | |
6577 | ||
a4f18ed1 | 6578 | /* |
4376cac6 SR |
6579 | * We only need to disable interrupts on start up |
6580 | * because we are modifying code that an interrupt | |
6581 | * may execute, and the modification is not atomic. | |
6582 | * But for modules, nothing runs the code we modify | |
6583 | * until we are finished with it, and there's no | |
6584 | * reason to cause large interrupt latencies while we do it. | |
a4f18ed1 | 6585 | */ |
4376cac6 SR |
6586 | if (!mod) |
6587 | local_irq_save(flags); | |
1dc43cf0 | 6588 | ftrace_update_code(mod, start_pg); |
4376cac6 SR |
6589 | if (!mod) |
6590 | local_irq_restore(flags); | |
a7900875 SR |
6591 | ret = 0; |
6592 | out: | |
e6ea44e9 | 6593 | mutex_unlock(&ftrace_lock); |
68bf21aa | 6594 | |
26efd79c ZY |
6595 | /* We should have used all pages unless we skipped some */ |
6596 | if (pg_unuse) { | |
6597 | WARN_ON(!skipped); | |
6598 | ftrace_free_pages(pg_unuse); | |
6599 | } | |
a7900875 | 6600 | return ret; |
68bf21aa SR |
6601 | } |
6602 | ||
aba4b5c2 SRV |
6603 | struct ftrace_mod_func { |
6604 | struct list_head list; | |
6605 | char *name; | |
6606 | unsigned long ip; | |
6607 | unsigned int size; | |
6608 | }; | |
6609 | ||
6610 | struct ftrace_mod_map { | |
6aa69784 | 6611 | struct rcu_head rcu; |
aba4b5c2 SRV |
6612 | struct list_head list; |
6613 | struct module *mod; | |
6614 | unsigned long start_addr; | |
6615 | unsigned long end_addr; | |
6616 | struct list_head funcs; | |
6171a031 | 6617 | unsigned int num_funcs; |
aba4b5c2 SRV |
6618 | }; |
6619 | ||
fc0ea795 AH |
6620 | static int ftrace_get_trampoline_kallsym(unsigned int symnum, |
6621 | unsigned long *value, char *type, | |
6622 | char *name, char *module_name, | |
6623 | int *exported) | |
6624 | { | |
6625 | struct ftrace_ops *op; | |
6626 | ||
6627 | list_for_each_entry_rcu(op, &ftrace_ops_trampoline_list, list) { | |
6628 | if (!op->trampoline || symnum--) | |
6629 | continue; | |
6630 | *value = op->trampoline; | |
6631 | *type = 't'; | |
d0c2d66f AS |
6632 | strscpy(name, FTRACE_TRAMPOLINE_SYM, KSYM_NAME_LEN); |
6633 | strscpy(module_name, FTRACE_TRAMPOLINE_MOD, MODULE_NAME_LEN); | |
fc0ea795 AH |
6634 | *exported = 0; |
6635 | return 0; | |
6636 | } | |
6637 | ||
6638 | return -ERANGE; | |
6639 | } | |
6640 | ||
123d6455 WJ |
6641 | #if defined(CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS) || defined(CONFIG_MODULES) |
6642 | /* | |
6643 | * Check if the current ops references the given ip. | |
6644 | * | |
6645 | * If the ops traces all functions, then it was already accounted for. | |
6646 | * If the ops does not trace the current record function, skip it. | |
6647 | * If the ops ignores the function via notrace filter, skip it. | |
6648 | */ | |
6649 | static bool | |
6650 | ops_references_ip(struct ftrace_ops *ops, unsigned long ip) | |
6651 | { | |
6652 | /* If ops isn't enabled, ignore it */ | |
6653 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
6654 | return false; | |
6655 | ||
6656 | /* If ops traces all then it includes this function */ | |
6657 | if (ops_traces_mod(ops)) | |
6658 | return true; | |
6659 | ||
6660 | /* The function must be in the filter */ | |
6661 | if (!ftrace_hash_empty(ops->func_hash->filter_hash) && | |
6662 | !__ftrace_lookup_ip(ops->func_hash->filter_hash, ip)) | |
6663 | return false; | |
6664 | ||
6665 | /* If in notrace hash, we ignore it too */ | |
6666 | if (ftrace_lookup_ip(ops->func_hash->notrace_hash, ip)) | |
6667 | return false; | |
6668 | ||
6669 | return true; | |
6670 | } | |
6671 | #endif | |
6672 | ||
93eb677d | 6673 | #ifdef CONFIG_MODULES |
32082309 SR |
6674 | |
6675 | #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next) | |
6676 | ||
6aa69784 SRV |
6677 | static LIST_HEAD(ftrace_mod_maps); |
6678 | ||
b7ffffbb SRRH |
6679 | static int referenced_filters(struct dyn_ftrace *rec) |
6680 | { | |
6681 | struct ftrace_ops *ops; | |
6682 | int cnt = 0; | |
6683 | ||
6684 | for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) { | |
123d6455 | 6685 | if (ops_references_ip(ops, rec->ip)) { |
c5f51572 CZ |
6686 | if (WARN_ON_ONCE(ops->flags & FTRACE_OPS_FL_DIRECT)) |
6687 | continue; | |
6688 | if (WARN_ON_ONCE(ops->flags & FTRACE_OPS_FL_IPMODIFY)) | |
6689 | continue; | |
8a224ffb CZ |
6690 | cnt++; |
6691 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) | |
6692 | rec->flags |= FTRACE_FL_REGS; | |
c5f51572 CZ |
6693 | if (cnt == 1 && ops->trampoline) |
6694 | rec->flags |= FTRACE_FL_TRAMP; | |
6695 | else | |
6696 | rec->flags &= ~FTRACE_FL_TRAMP; | |
8a224ffb | 6697 | } |
b7ffffbb SRRH |
6698 | } |
6699 | ||
6700 | return cnt; | |
6701 | } | |
6702 | ||
2a5bfe47 SRV |
6703 | static void |
6704 | clear_mod_from_hash(struct ftrace_page *pg, struct ftrace_hash *hash) | |
6705 | { | |
6706 | struct ftrace_func_entry *entry; | |
6707 | struct dyn_ftrace *rec; | |
6708 | int i; | |
6709 | ||
6710 | if (ftrace_hash_empty(hash)) | |
6711 | return; | |
6712 | ||
6713 | for (i = 0; i < pg->index; i++) { | |
6714 | rec = &pg->records[i]; | |
6715 | entry = __ftrace_lookup_ip(hash, rec->ip); | |
6716 | /* | |
6717 | * Do not allow this rec to match again. | |
6718 | * Yeah, it may waste some memory, but will be removed | |
6719 | * if/when the hash is modified again. | |
6720 | */ | |
6721 | if (entry) | |
6722 | entry->ip = 0; | |
6723 | } | |
6724 | } | |
6725 | ||
f2cc020d | 6726 | /* Clear any records from hashes */ |
2a5bfe47 SRV |
6727 | static void clear_mod_from_hashes(struct ftrace_page *pg) |
6728 | { | |
6729 | struct trace_array *tr; | |
6730 | ||
6731 | mutex_lock(&trace_types_lock); | |
6732 | list_for_each_entry(tr, &ftrace_trace_arrays, list) { | |
6733 | if (!tr->ops || !tr->ops->func_hash) | |
6734 | continue; | |
6735 | mutex_lock(&tr->ops->func_hash->regex_lock); | |
6736 | clear_mod_from_hash(pg, tr->ops->func_hash->filter_hash); | |
6737 | clear_mod_from_hash(pg, tr->ops->func_hash->notrace_hash); | |
6738 | mutex_unlock(&tr->ops->func_hash->regex_lock); | |
6739 | } | |
6740 | mutex_unlock(&trace_types_lock); | |
6741 | } | |
6742 | ||
6aa69784 SRV |
6743 | static void ftrace_free_mod_map(struct rcu_head *rcu) |
6744 | { | |
6745 | struct ftrace_mod_map *mod_map = container_of(rcu, struct ftrace_mod_map, rcu); | |
6746 | struct ftrace_mod_func *mod_func; | |
6747 | struct ftrace_mod_func *n; | |
6748 | ||
6749 | /* All the contents of mod_map are now not visible to readers */ | |
6750 | list_for_each_entry_safe(mod_func, n, &mod_map->funcs, list) { | |
6751 | kfree(mod_func->name); | |
6752 | list_del(&mod_func->list); | |
6753 | kfree(mod_func); | |
6754 | } | |
6755 | ||
6756 | kfree(mod_map); | |
6757 | } | |
6758 | ||
e7247a15 | 6759 | void ftrace_release_mod(struct module *mod) |
93eb677d | 6760 | { |
6aa69784 SRV |
6761 | struct ftrace_mod_map *mod_map; |
6762 | struct ftrace_mod_map *n; | |
93eb677d | 6763 | struct dyn_ftrace *rec; |
32082309 | 6764 | struct ftrace_page **last_pg; |
2a5bfe47 | 6765 | struct ftrace_page *tmp_page = NULL; |
93eb677d | 6766 | struct ftrace_page *pg; |
93eb677d | 6767 | |
45a4a237 SR |
6768 | mutex_lock(&ftrace_lock); |
6769 | ||
e7247a15 | 6770 | if (ftrace_disabled) |
45a4a237 | 6771 | goto out_unlock; |
93eb677d | 6772 | |
6aa69784 SRV |
6773 | list_for_each_entry_safe(mod_map, n, &ftrace_mod_maps, list) { |
6774 | if (mod_map->mod == mod) { | |
6775 | list_del_rcu(&mod_map->list); | |
74401729 | 6776 | call_rcu(&mod_map->rcu, ftrace_free_mod_map); |
6aa69784 SRV |
6777 | break; |
6778 | } | |
6779 | } | |
6780 | ||
32082309 SR |
6781 | /* |
6782 | * Each module has its own ftrace_pages, remove | |
6783 | * them from the list. | |
6784 | */ | |
6785 | last_pg = &ftrace_pages_start; | |
6786 | for (pg = ftrace_pages_start; pg; pg = *last_pg) { | |
6787 | rec = &pg->records[0]; | |
13511489 | 6788 | if (within_module(rec->ip, mod)) { |
93eb677d | 6789 | /* |
32082309 SR |
6790 | * As core pages are first, the first |
6791 | * page should never be a module page. | |
93eb677d | 6792 | */ |
32082309 SR |
6793 | if (WARN_ON(pg == ftrace_pages_start)) |
6794 | goto out_unlock; | |
6795 | ||
6796 | /* Check if we are deleting the last page */ | |
6797 | if (pg == ftrace_pages) | |
6798 | ftrace_pages = next_to_ftrace_page(last_pg); | |
6799 | ||
83dd1493 | 6800 | ftrace_update_tot_cnt -= pg->index; |
32082309 | 6801 | *last_pg = pg->next; |
2a5bfe47 SRV |
6802 | |
6803 | pg->next = tmp_page; | |
6804 | tmp_page = pg; | |
32082309 SR |
6805 | } else |
6806 | last_pg = &pg->next; | |
6807 | } | |
45a4a237 | 6808 | out_unlock: |
93eb677d | 6809 | mutex_unlock(&ftrace_lock); |
2a5bfe47 SRV |
6810 | |
6811 | for (pg = tmp_page; pg; pg = tmp_page) { | |
6812 | ||
6813 | /* Needs to be called outside of ftrace_lock */ | |
6814 | clear_mod_from_hashes(pg); | |
6815 | ||
db42523b LT |
6816 | if (pg->records) { |
6817 | free_pages((unsigned long)pg->records, pg->order); | |
6818 | ftrace_number_of_pages -= 1 << pg->order; | |
6819 | } | |
2a5bfe47 SRV |
6820 | tmp_page = pg->next; |
6821 | kfree(pg); | |
da537f0a | 6822 | ftrace_number_of_groups--; |
2a5bfe47 | 6823 | } |
93eb677d SR |
6824 | } |
6825 | ||
7dcd182b | 6826 | void ftrace_module_enable(struct module *mod) |
b7ffffbb SRRH |
6827 | { |
6828 | struct dyn_ftrace *rec; | |
6829 | struct ftrace_page *pg; | |
6830 | ||
6831 | mutex_lock(&ftrace_lock); | |
6832 | ||
6833 | if (ftrace_disabled) | |
6834 | goto out_unlock; | |
6835 | ||
6836 | /* | |
6837 | * If the tracing is enabled, go ahead and enable the record. | |
6838 | * | |
9efb85c5 | 6839 | * The reason not to enable the record immediately is the |
b7ffffbb SRRH |
6840 | * inherent check of ftrace_make_nop/ftrace_make_call for |
6841 | * correct previous instructions. Making first the NOP | |
6842 | * conversion puts the module to the correct state, thus | |
6843 | * passing the ftrace_make_call check. | |
6844 | * | |
6845 | * We also delay this to after the module code already set the | |
6846 | * text to read-only, as we now need to set it back to read-write | |
6847 | * so that we can modify the text. | |
6848 | */ | |
6849 | if (ftrace_start_up) | |
6850 | ftrace_arch_code_modify_prepare(); | |
6851 | ||
6852 | do_for_each_ftrace_rec(pg, rec) { | |
6853 | int cnt; | |
6854 | /* | |
6855 | * do_for_each_ftrace_rec() is a double loop. | |
6856 | * module text shares the pg. If a record is | |
6857 | * not part of this module, then skip this pg, | |
6858 | * which the "break" will do. | |
6859 | */ | |
13511489 | 6860 | if (!within_module(rec->ip, mod)) |
b7ffffbb SRRH |
6861 | break; |
6862 | ||
b39181f7 SRG |
6863 | /* Weak functions should still be ignored */ |
6864 | if (!test_for_valid_rec(rec)) { | |
6865 | /* Clear all other flags. Should not be enabled anyway */ | |
6866 | rec->flags = FTRACE_FL_DISABLED; | |
6867 | continue; | |
6868 | } | |
6869 | ||
b7ffffbb SRRH |
6870 | cnt = 0; |
6871 | ||
6872 | /* | |
6873 | * When adding a module, we need to check if tracers are | |
6874 | * currently enabled and if they are, and can trace this record, | |
6875 | * we need to enable the module functions as well as update the | |
6876 | * reference counts for those function records. | |
6877 | */ | |
6878 | if (ftrace_start_up) | |
6879 | cnt += referenced_filters(rec); | |
6880 | ||
8a224ffb CZ |
6881 | rec->flags &= ~FTRACE_FL_DISABLED; |
6882 | rec->flags += cnt; | |
b7ffffbb SRRH |
6883 | |
6884 | if (ftrace_start_up && cnt) { | |
6885 | int failed = __ftrace_replace_code(rec, 1); | |
6886 | if (failed) { | |
6887 | ftrace_bug(failed, rec); | |
6888 | goto out_loop; | |
6889 | } | |
6890 | } | |
6891 | ||
6892 | } while_for_each_ftrace_rec(); | |
6893 | ||
6894 | out_loop: | |
6895 | if (ftrace_start_up) | |
6896 | ftrace_arch_code_modify_post_process(); | |
6897 | ||
6898 | out_unlock: | |
6899 | mutex_unlock(&ftrace_lock); | |
d7fbf8df SRV |
6900 | |
6901 | process_cached_mods(mod->name); | |
b7ffffbb SRRH |
6902 | } |
6903 | ||
b6b71f66 | 6904 | void ftrace_module_init(struct module *mod) |
90d595fe | 6905 | { |
2889c658 YW |
6906 | int ret; |
6907 | ||
97e9b4fc | 6908 | if (ftrace_disabled || !mod->num_ftrace_callsites) |
fed1939c | 6909 | return; |
90d595fe | 6910 | |
2889c658 YW |
6911 | ret = ftrace_process_locs(mod, mod->ftrace_callsites, |
6912 | mod->ftrace_callsites + mod->num_ftrace_callsites); | |
6913 | if (ret) | |
6914 | pr_warn("ftrace: failed to allocate entries for module '%s' functions\n", | |
6915 | mod->name); | |
8c189ea6 | 6916 | } |
aba4b5c2 SRV |
6917 | |
6918 | static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map, | |
6919 | struct dyn_ftrace *rec) | |
6920 | { | |
6921 | struct ftrace_mod_func *mod_func; | |
6922 | unsigned long symsize; | |
6923 | unsigned long offset; | |
6924 | char str[KSYM_SYMBOL_LEN]; | |
6925 | char *modname; | |
6926 | const char *ret; | |
6927 | ||
6928 | ret = kallsyms_lookup(rec->ip, &symsize, &offset, &modname, str); | |
6929 | if (!ret) | |
6930 | return; | |
6931 | ||
6932 | mod_func = kmalloc(sizeof(*mod_func), GFP_KERNEL); | |
6933 | if (!mod_func) | |
6934 | return; | |
6935 | ||
6936 | mod_func->name = kstrdup(str, GFP_KERNEL); | |
6937 | if (!mod_func->name) { | |
6938 | kfree(mod_func); | |
6939 | return; | |
6940 | } | |
6941 | ||
6942 | mod_func->ip = rec->ip - offset; | |
6943 | mod_func->size = symsize; | |
6944 | ||
6171a031 SRV |
6945 | mod_map->num_funcs++; |
6946 | ||
aba4b5c2 SRV |
6947 | list_add_rcu(&mod_func->list, &mod_map->funcs); |
6948 | } | |
6949 | ||
aba4b5c2 SRV |
6950 | static struct ftrace_mod_map * |
6951 | allocate_ftrace_mod_map(struct module *mod, | |
6952 | unsigned long start, unsigned long end) | |
6953 | { | |
6954 | struct ftrace_mod_map *mod_map; | |
6955 | ||
6956 | mod_map = kmalloc(sizeof(*mod_map), GFP_KERNEL); | |
6957 | if (!mod_map) | |
6958 | return NULL; | |
6959 | ||
6960 | mod_map->mod = mod; | |
6961 | mod_map->start_addr = start; | |
6962 | mod_map->end_addr = end; | |
6171a031 | 6963 | mod_map->num_funcs = 0; |
aba4b5c2 SRV |
6964 | |
6965 | INIT_LIST_HEAD_RCU(&mod_map->funcs); | |
6966 | ||
6967 | list_add_rcu(&mod_map->list, &ftrace_mod_maps); | |
6968 | ||
6969 | return mod_map; | |
6970 | } | |
6971 | ||
6972 | static const char * | |
6973 | ftrace_func_address_lookup(struct ftrace_mod_map *mod_map, | |
6974 | unsigned long addr, unsigned long *size, | |
6975 | unsigned long *off, char *sym) | |
6976 | { | |
6977 | struct ftrace_mod_func *found_func = NULL; | |
6978 | struct ftrace_mod_func *mod_func; | |
6979 | ||
6980 | list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) { | |
6981 | if (addr >= mod_func->ip && | |
6982 | addr < mod_func->ip + mod_func->size) { | |
6983 | found_func = mod_func; | |
6984 | break; | |
6985 | } | |
6986 | } | |
6987 | ||
6988 | if (found_func) { | |
6989 | if (size) | |
6990 | *size = found_func->size; | |
6991 | if (off) | |
6992 | *off = addr - found_func->ip; | |
6993 | if (sym) | |
d0c2d66f | 6994 | strscpy(sym, found_func->name, KSYM_NAME_LEN); |
aba4b5c2 SRV |
6995 | |
6996 | return found_func->name; | |
6997 | } | |
6998 | ||
6999 | return NULL; | |
7000 | } | |
7001 | ||
7002 | const char * | |
7003 | ftrace_mod_address_lookup(unsigned long addr, unsigned long *size, | |
7004 | unsigned long *off, char **modname, char *sym) | |
7005 | { | |
7006 | struct ftrace_mod_map *mod_map; | |
7007 | const char *ret = NULL; | |
7008 | ||
74401729 | 7009 | /* mod_map is freed via call_rcu() */ |
aba4b5c2 SRV |
7010 | preempt_disable(); |
7011 | list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) { | |
7012 | ret = ftrace_func_address_lookup(mod_map, addr, size, off, sym); | |
7013 | if (ret) { | |
7014 | if (modname) | |
7015 | *modname = mod_map->mod->name; | |
7016 | break; | |
7017 | } | |
7018 | } | |
7019 | preempt_enable(); | |
7020 | ||
7021 | return ret; | |
7022 | } | |
7023 | ||
6171a031 SRV |
7024 | int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value, |
7025 | char *type, char *name, | |
7026 | char *module_name, int *exported) | |
7027 | { | |
7028 | struct ftrace_mod_map *mod_map; | |
7029 | struct ftrace_mod_func *mod_func; | |
fc0ea795 | 7030 | int ret; |
6171a031 SRV |
7031 | |
7032 | preempt_disable(); | |
7033 | list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) { | |
7034 | ||
7035 | if (symnum >= mod_map->num_funcs) { | |
7036 | symnum -= mod_map->num_funcs; | |
7037 | continue; | |
7038 | } | |
7039 | ||
7040 | list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) { | |
7041 | if (symnum > 1) { | |
7042 | symnum--; | |
7043 | continue; | |
7044 | } | |
7045 | ||
7046 | *value = mod_func->ip; | |
7047 | *type = 'T'; | |
d0c2d66f AS |
7048 | strscpy(name, mod_func->name, KSYM_NAME_LEN); |
7049 | strscpy(module_name, mod_map->mod->name, MODULE_NAME_LEN); | |
6171a031 SRV |
7050 | *exported = 1; |
7051 | preempt_enable(); | |
7052 | return 0; | |
7053 | } | |
7054 | WARN_ON(1); | |
7055 | break; | |
7056 | } | |
fc0ea795 AH |
7057 | ret = ftrace_get_trampoline_kallsym(symnum, value, type, name, |
7058 | module_name, exported); | |
6171a031 | 7059 | preempt_enable(); |
fc0ea795 | 7060 | return ret; |
6171a031 SRV |
7061 | } |
7062 | ||
aba4b5c2 SRV |
7063 | #else |
7064 | static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map, | |
7065 | struct dyn_ftrace *rec) { } | |
7066 | static inline struct ftrace_mod_map * | |
7067 | allocate_ftrace_mod_map(struct module *mod, | |
7068 | unsigned long start, unsigned long end) | |
7069 | { | |
7070 | return NULL; | |
7071 | } | |
fc0ea795 AH |
7072 | int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value, |
7073 | char *type, char *name, char *module_name, | |
7074 | int *exported) | |
7075 | { | |
7076 | int ret; | |
7077 | ||
7078 | preempt_disable(); | |
7079 | ret = ftrace_get_trampoline_kallsym(symnum, value, type, name, | |
7080 | module_name, exported); | |
7081 | preempt_enable(); | |
7082 | return ret; | |
7083 | } | |
93eb677d SR |
7084 | #endif /* CONFIG_MODULES */ |
7085 | ||
8715b108 JF |
7086 | struct ftrace_init_func { |
7087 | struct list_head list; | |
7088 | unsigned long ip; | |
7089 | }; | |
7090 | ||
7091 | /* Clear any init ips from hashes */ | |
7092 | static void | |
7093 | clear_func_from_hash(struct ftrace_init_func *func, struct ftrace_hash *hash) | |
42c269c8 | 7094 | { |
8715b108 JF |
7095 | struct ftrace_func_entry *entry; |
7096 | ||
08468754 | 7097 | entry = ftrace_lookup_ip(hash, func->ip); |
8715b108 JF |
7098 | /* |
7099 | * Do not allow this rec to match again. | |
7100 | * Yeah, it may waste some memory, but will be removed | |
7101 | * if/when the hash is modified again. | |
7102 | */ | |
7103 | if (entry) | |
7104 | entry->ip = 0; | |
7105 | } | |
7106 | ||
7107 | static void | |
7108 | clear_func_from_hashes(struct ftrace_init_func *func) | |
7109 | { | |
7110 | struct trace_array *tr; | |
7111 | ||
7112 | mutex_lock(&trace_types_lock); | |
7113 | list_for_each_entry(tr, &ftrace_trace_arrays, list) { | |
7114 | if (!tr->ops || !tr->ops->func_hash) | |
7115 | continue; | |
7116 | mutex_lock(&tr->ops->func_hash->regex_lock); | |
7117 | clear_func_from_hash(func, tr->ops->func_hash->filter_hash); | |
7118 | clear_func_from_hash(func, tr->ops->func_hash->notrace_hash); | |
7119 | mutex_unlock(&tr->ops->func_hash->regex_lock); | |
7120 | } | |
7121 | mutex_unlock(&trace_types_lock); | |
7122 | } | |
7123 | ||
7124 | static void add_to_clear_hash_list(struct list_head *clear_list, | |
7125 | struct dyn_ftrace *rec) | |
7126 | { | |
7127 | struct ftrace_init_func *func; | |
7128 | ||
7129 | func = kmalloc(sizeof(*func), GFP_KERNEL); | |
7130 | if (!func) { | |
24589e3a | 7131 | MEM_FAIL(1, "alloc failure, ftrace filter could be stale\n"); |
8715b108 JF |
7132 | return; |
7133 | } | |
7134 | ||
7135 | func->ip = rec->ip; | |
7136 | list_add(&func->list, clear_list); | |
7137 | } | |
7138 | ||
aba4b5c2 | 7139 | void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr) |
42c269c8 | 7140 | { |
6cafbe15 SRV |
7141 | unsigned long start = (unsigned long)(start_ptr); |
7142 | unsigned long end = (unsigned long)(end_ptr); | |
42c269c8 SRV |
7143 | struct ftrace_page **last_pg = &ftrace_pages_start; |
7144 | struct ftrace_page *pg; | |
7145 | struct dyn_ftrace *rec; | |
7146 | struct dyn_ftrace key; | |
aba4b5c2 | 7147 | struct ftrace_mod_map *mod_map = NULL; |
8715b108 | 7148 | struct ftrace_init_func *func, *func_next; |
2a30dbcb | 7149 | LIST_HEAD(clear_hash); |
8715b108 | 7150 | |
42c269c8 SRV |
7151 | key.ip = start; |
7152 | key.flags = end; /* overload flags, as it is unsigned long */ | |
7153 | ||
7154 | mutex_lock(&ftrace_lock); | |
7155 | ||
aba4b5c2 SRV |
7156 | /* |
7157 | * If we are freeing module init memory, then check if | |
7158 | * any tracer is active. If so, we need to save a mapping of | |
7159 | * the module functions being freed with the address. | |
7160 | */ | |
7161 | if (mod && ftrace_ops_list != &ftrace_list_end) | |
7162 | mod_map = allocate_ftrace_mod_map(mod, start, end); | |
7163 | ||
42c269c8 SRV |
7164 | for (pg = ftrace_pages_start; pg; last_pg = &pg->next, pg = *last_pg) { |
7165 | if (end < pg->records[0].ip || | |
7166 | start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE)) | |
7167 | continue; | |
7168 | again: | |
7169 | rec = bsearch(&key, pg->records, pg->index, | |
7170 | sizeof(struct dyn_ftrace), | |
7171 | ftrace_cmp_recs); | |
7172 | if (!rec) | |
7173 | continue; | |
aba4b5c2 | 7174 | |
8715b108 JF |
7175 | /* rec will be cleared from hashes after ftrace_lock unlock */ |
7176 | add_to_clear_hash_list(&clear_hash, rec); | |
7177 | ||
aba4b5c2 SRV |
7178 | if (mod_map) |
7179 | save_ftrace_mod_rec(mod_map, rec); | |
7180 | ||
42c269c8 | 7181 | pg->index--; |
4ec78467 | 7182 | ftrace_update_tot_cnt--; |
42c269c8 SRV |
7183 | if (!pg->index) { |
7184 | *last_pg = pg->next; | |
db42523b LT |
7185 | if (pg->records) { |
7186 | free_pages((unsigned long)pg->records, pg->order); | |
7187 | ftrace_number_of_pages -= 1 << pg->order; | |
7188 | } | |
da537f0a | 7189 | ftrace_number_of_groups--; |
42c269c8 SRV |
7190 | kfree(pg); |
7191 | pg = container_of(last_pg, struct ftrace_page, next); | |
7192 | if (!(*last_pg)) | |
7193 | ftrace_pages = pg; | |
7194 | continue; | |
7195 | } | |
7196 | memmove(rec, rec + 1, | |
7197 | (pg->index - (rec - pg->records)) * sizeof(*rec)); | |
7198 | /* More than one function may be in this block */ | |
7199 | goto again; | |
7200 | } | |
7201 | mutex_unlock(&ftrace_lock); | |
8715b108 JF |
7202 | |
7203 | list_for_each_entry_safe(func, func_next, &clear_hash, list) { | |
7204 | clear_func_from_hashes(func); | |
7205 | kfree(func); | |
7206 | } | |
42c269c8 SRV |
7207 | } |
7208 | ||
6cafbe15 SRV |
7209 | void __init ftrace_free_init_mem(void) |
7210 | { | |
7211 | void *start = (void *)(&__init_begin); | |
7212 | void *end = (void *)(&__init_end); | |
7213 | ||
380af29b SRG |
7214 | ftrace_boot_snapshot(); |
7215 | ||
aba4b5c2 | 7216 | ftrace_free_mem(NULL, start, end); |
42c269c8 SRV |
7217 | } |
7218 | ||
6644c654 WO |
7219 | int __init __weak ftrace_dyn_arch_init(void) |
7220 | { | |
7221 | return 0; | |
7222 | } | |
7223 | ||
68bf21aa SR |
7224 | void __init ftrace_init(void) |
7225 | { | |
1dc43cf0 JS |
7226 | extern unsigned long __start_mcount_loc[]; |
7227 | extern unsigned long __stop_mcount_loc[]; | |
3a36cb11 | 7228 | unsigned long count, flags; |
68bf21aa SR |
7229 | int ret; |
7230 | ||
68bf21aa | 7231 | local_irq_save(flags); |
3a36cb11 | 7232 | ret = ftrace_dyn_arch_init(); |
68bf21aa | 7233 | local_irq_restore(flags); |
af64a7cb | 7234 | if (ret) |
68bf21aa SR |
7235 | goto failed; |
7236 | ||
7237 | count = __stop_mcount_loc - __start_mcount_loc; | |
c867ccd8 JS |
7238 | if (!count) { |
7239 | pr_info("ftrace: No functions to be traced?\n"); | |
68bf21aa | 7240 | goto failed; |
c867ccd8 JS |
7241 | } |
7242 | ||
7243 | pr_info("ftrace: allocating %ld entries in %ld pages\n", | |
08948cae | 7244 | count, DIV_ROUND_UP(count, ENTRIES_PER_PAGE)); |
68bf21aa | 7245 | |
5cb084bb | 7246 | ret = ftrace_process_locs(NULL, |
31e88909 | 7247 | __start_mcount_loc, |
68bf21aa | 7248 | __stop_mcount_loc); |
2889c658 YW |
7249 | if (ret) { |
7250 | pr_warn("ftrace: failed to allocate entries for functions\n"); | |
7251 | goto failed; | |
7252 | } | |
68bf21aa | 7253 | |
da537f0a SRV |
7254 | pr_info("ftrace: allocated %ld pages with %ld groups\n", |
7255 | ftrace_number_of_pages, ftrace_number_of_groups); | |
7256 | ||
2889c658 YW |
7257 | last_ftrace_enabled = ftrace_enabled = 1; |
7258 | ||
2af15d6a SR |
7259 | set_ftrace_early_filters(); |
7260 | ||
68bf21aa SR |
7261 | return; |
7262 | failed: | |
7263 | ftrace_disabled = 1; | |
7264 | } | |
68bf21aa | 7265 | |
f3bea491 SRRH |
7266 | /* Do nothing if arch does not support this */ |
7267 | void __weak arch_ftrace_update_trampoline(struct ftrace_ops *ops) | |
7268 | { | |
7269 | } | |
7270 | ||
7271 | static void ftrace_update_trampoline(struct ftrace_ops *ops) | |
7272 | { | |
fc0ea795 AH |
7273 | unsigned long trampoline = ops->trampoline; |
7274 | ||
f3bea491 | 7275 | arch_ftrace_update_trampoline(ops); |
fc0ea795 | 7276 | if (ops->trampoline && ops->trampoline != trampoline && |
dd9ddf46 AH |
7277 | (ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP)) { |
7278 | /* Add to kallsyms before the perf events */ | |
fc0ea795 | 7279 | ftrace_add_trampoline_to_kallsyms(ops); |
dd9ddf46 AH |
7280 | perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_OOL, |
7281 | ops->trampoline, ops->trampoline_size, false, | |
7282 | FTRACE_TRAMPOLINE_SYM); | |
548e1f6c AH |
7283 | /* |
7284 | * Record the perf text poke event after the ksymbol register | |
7285 | * event. | |
7286 | */ | |
7287 | perf_event_text_poke((void *)ops->trampoline, NULL, 0, | |
7288 | (void *)ops->trampoline, | |
7289 | ops->trampoline_size); | |
dd9ddf46 | 7290 | } |
f3bea491 SRRH |
7291 | } |
7292 | ||
04ec7bb6 SRV |
7293 | void ftrace_init_trace_array(struct trace_array *tr) |
7294 | { | |
7295 | INIT_LIST_HEAD(&tr->func_probes); | |
673feb9d SRV |
7296 | INIT_LIST_HEAD(&tr->mod_trace); |
7297 | INIT_LIST_HEAD(&tr->mod_notrace); | |
04ec7bb6 | 7298 | } |
3d083395 | 7299 | #else |
0b6e4d56 | 7300 | |
3306fc4a | 7301 | struct ftrace_ops global_ops = { |
bd69c30b | 7302 | .func = ftrace_stub, |
a25d036d | 7303 | .flags = FTRACE_OPS_FL_INITIALIZED | |
e3eea140 | 7304 | FTRACE_OPS_FL_PID, |
bd69c30b SR |
7305 | }; |
7306 | ||
0b6e4d56 FW |
7307 | static int __init ftrace_nodyn_init(void) |
7308 | { | |
7309 | ftrace_enabled = 1; | |
7310 | return 0; | |
7311 | } | |
6f415672 | 7312 | core_initcall(ftrace_nodyn_init); |
0b6e4d56 | 7313 | |
8434dc93 | 7314 | static inline int ftrace_init_dyn_tracefs(struct dentry *d_tracer) { return 0; } |
e1effa01 | 7315 | static inline void ftrace_startup_all(int command) { } |
8a56d776 | 7316 | |
f3bea491 SRRH |
7317 | static void ftrace_update_trampoline(struct ftrace_ops *ops) |
7318 | { | |
7319 | } | |
7320 | ||
3d083395 SR |
7321 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
7322 | ||
4104d326 SRRH |
7323 | __init void ftrace_init_global_array_ops(struct trace_array *tr) |
7324 | { | |
7325 | tr->ops = &global_ops; | |
7326 | tr->ops->private = tr; | |
04ec7bb6 | 7327 | ftrace_init_trace_array(tr); |
4104d326 SRRH |
7328 | } |
7329 | ||
7330 | void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func) | |
7331 | { | |
7332 | /* If we filter on pids, update to use the pid function */ | |
7333 | if (tr->flags & TRACE_ARRAY_FL_GLOBAL) { | |
7334 | if (WARN_ON(tr->ops->func != ftrace_stub)) | |
7335 | printk("ftrace ops had %pS for function\n", | |
7336 | tr->ops->func); | |
4104d326 SRRH |
7337 | } |
7338 | tr->ops->func = func; | |
7339 | tr->ops->private = tr; | |
7340 | } | |
7341 | ||
7342 | void ftrace_reset_array_ops(struct trace_array *tr) | |
7343 | { | |
7344 | tr->ops->func = ftrace_stub; | |
7345 | } | |
7346 | ||
fabe38ab | 7347 | static nokprobe_inline void |
2f5f6ad9 | 7348 | __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, |
d19ad077 | 7349 | struct ftrace_ops *ignored, struct ftrace_regs *fregs) |
b848914c | 7350 | { |
d19ad077 | 7351 | struct pt_regs *regs = ftrace_get_regs(fregs); |
cdbe61bf | 7352 | struct ftrace_ops *op; |
edc15caf | 7353 | int bit; |
b848914c | 7354 | |
ce5e4803 | 7355 | /* |
7356 | * The ftrace_test_and_set_recursion() will disable preemption, | |
7357 | * which is required since some of the ops may be dynamically | |
7358 | * allocated, they must be freed after a synchronize_rcu(). | |
7359 | */ | |
ed65df63 | 7360 | bit = trace_test_and_set_recursion(ip, parent_ip, TRACE_LIST_START); |
edc15caf SR |
7361 | if (bit < 0) |
7362 | return; | |
b1cff0ad | 7363 | |
0a016409 | 7364 | do_for_each_ftrace_op(op, ftrace_ops_list) { |
2fa717a0 SRV |
7365 | /* Stub functions don't need to be called nor tested */ |
7366 | if (op->flags & FTRACE_OPS_FL_STUB) | |
7367 | continue; | |
ba27f2bc SRRH |
7368 | /* |
7369 | * Check the following for each ops before calling their func: | |
7370 | * if RCU flag is set, then rcu_is_watching() must be true | |
ba27f2bc SRRH |
7371 | * Otherwise test if the ip matches the ops filter |
7372 | * | |
7373 | * If any of the above fails then the op->func() is not executed. | |
7374 | */ | |
7375 | if ((!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching()) && | |
ba27f2bc | 7376 | ftrace_ops_test(op, ip, regs)) { |
1d48d596 SRRH |
7377 | if (FTRACE_WARN_ON(!op->func)) { |
7378 | pr_warn("op=%p %pS\n", op, op); | |
4104d326 SRRH |
7379 | goto out; |
7380 | } | |
d19ad077 | 7381 | op->func(ip, parent_ip, op, fregs); |
4104d326 | 7382 | } |
0a016409 | 7383 | } while_for_each_ftrace_op(op); |
4104d326 | 7384 | out: |
edc15caf | 7385 | trace_clear_recursion(bit); |
b848914c SR |
7386 | } |
7387 | ||
2f5f6ad9 SR |
7388 | /* |
7389 | * Some archs only support passing ip and parent_ip. Even though | |
7390 | * the list function ignores the op parameter, we do not want any | |
7391 | * C side effects, where a function is called without the caller | |
7392 | * sending a third parameter. | |
a1e2e31d SR |
7393 | * Archs are to support both the regs and ftrace_ops at the same time. |
7394 | * If they support ftrace_ops, it is assumed they support regs. | |
7395 | * If call backs want to use regs, they must either check for regs | |
06aeaaea MH |
7396 | * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS. |
7397 | * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved. | |
a1e2e31d | 7398 | * An architecture can pass partial regs with ftrace_ops and still |
b8ec330a | 7399 | * set the ARCH_SUPPORTS_FTRACE_OPS. |
34cdd18b SRV |
7400 | * |
7401 | * In vmlinux.lds.h, ftrace_ops_list_func() is defined to be | |
7402 | * arch_ftrace_ops_list_func. | |
2f5f6ad9 SR |
7403 | */ |
7404 | #if ARCH_SUPPORTS_FTRACE_OPS | |
34cdd18b SRV |
7405 | void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, |
7406 | struct ftrace_ops *op, struct ftrace_regs *fregs) | |
2f5f6ad9 | 7407 | { |
d19ad077 | 7408 | __ftrace_ops_list_func(ip, parent_ip, NULL, fregs); |
2f5f6ad9 SR |
7409 | } |
7410 | #else | |
34cdd18b | 7411 | void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip) |
2f5f6ad9 | 7412 | { |
a1e2e31d | 7413 | __ftrace_ops_list_func(ip, parent_ip, NULL, NULL); |
2f5f6ad9 SR |
7414 | } |
7415 | #endif | |
34cdd18b | 7416 | NOKPROBE_SYMBOL(arch_ftrace_ops_list_func); |
2f5f6ad9 | 7417 | |
f1ff6348 SRRH |
7418 | /* |
7419 | * If there's only one function registered but it does not support | |
78a01feb ZY |
7420 | * recursion, needs RCU protection, then this function will be called |
7421 | * by the mcount trampoline. | |
f1ff6348 | 7422 | */ |
c68c0fa2 | 7423 | static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip, |
d19ad077 | 7424 | struct ftrace_ops *op, struct ftrace_regs *fregs) |
f1ff6348 SRRH |
7425 | { |
7426 | int bit; | |
7427 | ||
ed65df63 | 7428 | bit = trace_test_and_set_recursion(ip, parent_ip, TRACE_LIST_START); |
f1ff6348 SRRH |
7429 | if (bit < 0) |
7430 | return; | |
7431 | ||
b40341fa | 7432 | if (!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching()) |
d19ad077 | 7433 | op->func(ip, parent_ip, op, fregs); |
c68c0fa2 | 7434 | |
f1ff6348 SRRH |
7435 | trace_clear_recursion(bit); |
7436 | } | |
fabe38ab | 7437 | NOKPROBE_SYMBOL(ftrace_ops_assist_func); |
f1ff6348 | 7438 | |
87354059 SRRH |
7439 | /** |
7440 | * ftrace_ops_get_func - get the function a trampoline should call | |
7441 | * @ops: the ops to get the function for | |
7442 | * | |
7443 | * Normally the mcount trampoline will call the ops->func, but there | |
7444 | * are times that it should not. For example, if the ops does not | |
7445 | * have its own recursion protection, then it should call the | |
3a150df9 | 7446 | * ftrace_ops_assist_func() instead. |
87354059 | 7447 | * |
d1530413 | 7448 | * Returns: the function that the trampoline should call for @ops. |
87354059 SRRH |
7449 | */ |
7450 | ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops) | |
7451 | { | |
87354059 | 7452 | /* |
a25d036d SRV |
7453 | * If the function does not handle recursion or needs to be RCU safe, |
7454 | * then we need to call the assist handler. | |
87354059 | 7455 | */ |
a25d036d SRV |
7456 | if (ops->flags & (FTRACE_OPS_FL_RECURSION | |
7457 | FTRACE_OPS_FL_RCU)) | |
c68c0fa2 | 7458 | return ftrace_ops_assist_func; |
87354059 SRRH |
7459 | |
7460 | return ops->func; | |
7461 | } | |
7462 | ||
345ddcc8 SRRH |
7463 | static void |
7464 | ftrace_filter_pid_sched_switch_probe(void *data, bool preempt, | |
fa2c3254 | 7465 | struct task_struct *prev, |
9c2136be DK |
7466 | struct task_struct *next, |
7467 | unsigned int prev_state) | |
978f3a45 | 7468 | { |
345ddcc8 SRRH |
7469 | struct trace_array *tr = data; |
7470 | struct trace_pid_list *pid_list; | |
b3b1e6ed | 7471 | struct trace_pid_list *no_pid_list; |
978f3a45 | 7472 | |
345ddcc8 | 7473 | pid_list = rcu_dereference_sched(tr->function_pids); |
b3b1e6ed | 7474 | no_pid_list = rcu_dereference_sched(tr->function_no_pids); |
e32d8956 | 7475 | |
b3b1e6ed | 7476 | if (trace_ignore_this_task(pid_list, no_pid_list, next)) |
717e3f5e SRV |
7477 | this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid, |
7478 | FTRACE_PID_IGNORE); | |
7479 | else | |
7480 | this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid, | |
7481 | next->pid); | |
978f3a45 SR |
7482 | } |
7483 | ||
1e10486f NK |
7484 | static void |
7485 | ftrace_pid_follow_sched_process_fork(void *data, | |
7486 | struct task_struct *self, | |
7487 | struct task_struct *task) | |
7488 | { | |
7489 | struct trace_pid_list *pid_list; | |
7490 | struct trace_array *tr = data; | |
7491 | ||
7492 | pid_list = rcu_dereference_sched(tr->function_pids); | |
7493 | trace_filter_add_remove_task(pid_list, self, task); | |
b3b1e6ed SRV |
7494 | |
7495 | pid_list = rcu_dereference_sched(tr->function_no_pids); | |
7496 | trace_filter_add_remove_task(pid_list, self, task); | |
1e10486f NK |
7497 | } |
7498 | ||
7499 | static void | |
7500 | ftrace_pid_follow_sched_process_exit(void *data, struct task_struct *task) | |
7501 | { | |
7502 | struct trace_pid_list *pid_list; | |
7503 | struct trace_array *tr = data; | |
7504 | ||
7505 | pid_list = rcu_dereference_sched(tr->function_pids); | |
7506 | trace_filter_add_remove_task(pid_list, NULL, task); | |
b3b1e6ed SRV |
7507 | |
7508 | pid_list = rcu_dereference_sched(tr->function_no_pids); | |
7509 | trace_filter_add_remove_task(pid_list, NULL, task); | |
1e10486f NK |
7510 | } |
7511 | ||
7512 | void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) | |
7513 | { | |
7514 | if (enable) { | |
7515 | register_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork, | |
7516 | tr); | |
afcab636 | 7517 | register_trace_sched_process_free(ftrace_pid_follow_sched_process_exit, |
1e10486f NK |
7518 | tr); |
7519 | } else { | |
7520 | unregister_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork, | |
7521 | tr); | |
afcab636 | 7522 | unregister_trace_sched_process_free(ftrace_pid_follow_sched_process_exit, |
1e10486f NK |
7523 | tr); |
7524 | } | |
7525 | } | |
7526 | ||
b3b1e6ed | 7527 | static void clear_ftrace_pids(struct trace_array *tr, int type) |
e32d8956 | 7528 | { |
345ddcc8 | 7529 | struct trace_pid_list *pid_list; |
b3b1e6ed | 7530 | struct trace_pid_list *no_pid_list; |
345ddcc8 | 7531 | int cpu; |
e32d8956 | 7532 | |
345ddcc8 SRRH |
7533 | pid_list = rcu_dereference_protected(tr->function_pids, |
7534 | lockdep_is_held(&ftrace_lock)); | |
b3b1e6ed SRV |
7535 | no_pid_list = rcu_dereference_protected(tr->function_no_pids, |
7536 | lockdep_is_held(&ftrace_lock)); | |
7537 | ||
7538 | /* Make sure there's something to do */ | |
27683626 | 7539 | if (!pid_type_enabled(type, pid_list, no_pid_list)) |
345ddcc8 | 7540 | return; |
229c4ef8 | 7541 | |
b3b1e6ed | 7542 | /* See if the pids still need to be checked after this */ |
27683626 | 7543 | if (!still_need_pid_events(type, pid_list, no_pid_list)) { |
b3b1e6ed SRV |
7544 | unregister_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr); |
7545 | for_each_possible_cpu(cpu) | |
7546 | per_cpu_ptr(tr->array_buffer.data, cpu)->ftrace_ignore_pid = FTRACE_PID_TRACE; | |
7547 | } | |
e32d8956 | 7548 | |
b3b1e6ed SRV |
7549 | if (type & TRACE_PIDS) |
7550 | rcu_assign_pointer(tr->function_pids, NULL); | |
978f3a45 | 7551 | |
b3b1e6ed SRV |
7552 | if (type & TRACE_NO_PIDS) |
7553 | rcu_assign_pointer(tr->function_no_pids, NULL); | |
978f3a45 | 7554 | |
345ddcc8 | 7555 | /* Wait till all users are no longer using pid filtering */ |
74401729 | 7556 | synchronize_rcu(); |
e32d8956 | 7557 | |
b3b1e6ed | 7558 | if ((type & TRACE_PIDS) && pid_list) |
6954e415 | 7559 | trace_pid_list_free(pid_list); |
b3b1e6ed SRV |
7560 | |
7561 | if ((type & TRACE_NO_PIDS) && no_pid_list) | |
6954e415 | 7562 | trace_pid_list_free(no_pid_list); |
e32d8956 SR |
7563 | } |
7564 | ||
d879d0b8 NK |
7565 | void ftrace_clear_pids(struct trace_array *tr) |
7566 | { | |
7567 | mutex_lock(&ftrace_lock); | |
7568 | ||
b3b1e6ed | 7569 | clear_ftrace_pids(tr, TRACE_PIDS | TRACE_NO_PIDS); |
d879d0b8 NK |
7570 | |
7571 | mutex_unlock(&ftrace_lock); | |
7572 | } | |
7573 | ||
b3b1e6ed | 7574 | static void ftrace_pid_reset(struct trace_array *tr, int type) |
df4fc315 | 7575 | { |
756d17ee | 7576 | mutex_lock(&ftrace_lock); |
b3b1e6ed | 7577 | clear_ftrace_pids(tr, type); |
978f3a45 | 7578 | |
756d17ee | 7579 | ftrace_update_pid_func(); |
e1effa01 | 7580 | ftrace_startup_all(0); |
756d17ee | 7581 | |
7582 | mutex_unlock(&ftrace_lock); | |
756d17ee | 7583 | } |
7584 | ||
345ddcc8 SRRH |
7585 | /* Greater than any max PID */ |
7586 | #define FTRACE_NO_PIDS (void *)(PID_MAX_LIMIT + 1) | |
df4fc315 | 7587 | |
756d17ee | 7588 | static void *fpid_start(struct seq_file *m, loff_t *pos) |
345ddcc8 | 7589 | __acquires(RCU) |
756d17ee | 7590 | { |
345ddcc8 SRRH |
7591 | struct trace_pid_list *pid_list; |
7592 | struct trace_array *tr = m->private; | |
7593 | ||
756d17ee | 7594 | mutex_lock(&ftrace_lock); |
345ddcc8 SRRH |
7595 | rcu_read_lock_sched(); |
7596 | ||
7597 | pid_list = rcu_dereference_sched(tr->function_pids); | |
756d17ee | 7598 | |
345ddcc8 SRRH |
7599 | if (!pid_list) |
7600 | return !(*pos) ? FTRACE_NO_PIDS : NULL; | |
756d17ee | 7601 | |
345ddcc8 | 7602 | return trace_pid_start(pid_list, pos); |
756d17ee | 7603 | } |
7604 | ||
7605 | static void *fpid_next(struct seq_file *m, void *v, loff_t *pos) | |
7606 | { | |
345ddcc8 SRRH |
7607 | struct trace_array *tr = m->private; |
7608 | struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_pids); | |
7609 | ||
e4075e8b VA |
7610 | if (v == FTRACE_NO_PIDS) { |
7611 | (*pos)++; | |
756d17ee | 7612 | return NULL; |
e4075e8b | 7613 | } |
345ddcc8 | 7614 | return trace_pid_next(pid_list, v, pos); |
756d17ee | 7615 | } |
7616 | ||
7617 | static void fpid_stop(struct seq_file *m, void *p) | |
345ddcc8 | 7618 | __releases(RCU) |
756d17ee | 7619 | { |
345ddcc8 | 7620 | rcu_read_unlock_sched(); |
756d17ee | 7621 | mutex_unlock(&ftrace_lock); |
7622 | } | |
7623 | ||
7624 | static int fpid_show(struct seq_file *m, void *v) | |
7625 | { | |
345ddcc8 | 7626 | if (v == FTRACE_NO_PIDS) { |
fa6f0cc7 | 7627 | seq_puts(m, "no pid\n"); |
756d17ee | 7628 | return 0; |
7629 | } | |
7630 | ||
345ddcc8 | 7631 | return trace_pid_show(m, v); |
756d17ee | 7632 | } |
7633 | ||
7634 | static const struct seq_operations ftrace_pid_sops = { | |
7635 | .start = fpid_start, | |
7636 | .next = fpid_next, | |
7637 | .stop = fpid_stop, | |
7638 | .show = fpid_show, | |
7639 | }; | |
7640 | ||
b3b1e6ed SRV |
7641 | static void *fnpid_start(struct seq_file *m, loff_t *pos) |
7642 | __acquires(RCU) | |
7643 | { | |
7644 | struct trace_pid_list *pid_list; | |
7645 | struct trace_array *tr = m->private; | |
7646 | ||
7647 | mutex_lock(&ftrace_lock); | |
7648 | rcu_read_lock_sched(); | |
7649 | ||
7650 | pid_list = rcu_dereference_sched(tr->function_no_pids); | |
7651 | ||
7652 | if (!pid_list) | |
7653 | return !(*pos) ? FTRACE_NO_PIDS : NULL; | |
7654 | ||
7655 | return trace_pid_start(pid_list, pos); | |
7656 | } | |
7657 | ||
7658 | static void *fnpid_next(struct seq_file *m, void *v, loff_t *pos) | |
756d17ee | 7659 | { |
b3b1e6ed SRV |
7660 | struct trace_array *tr = m->private; |
7661 | struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_no_pids); | |
7662 | ||
7663 | if (v == FTRACE_NO_PIDS) { | |
7664 | (*pos)++; | |
7665 | return NULL; | |
7666 | } | |
7667 | return trace_pid_next(pid_list, v, pos); | |
7668 | } | |
7669 | ||
7670 | static const struct seq_operations ftrace_no_pid_sops = { | |
7671 | .start = fnpid_start, | |
7672 | .next = fnpid_next, | |
7673 | .stop = fpid_stop, | |
7674 | .show = fpid_show, | |
7675 | }; | |
7676 | ||
7677 | static int pid_open(struct inode *inode, struct file *file, int type) | |
7678 | { | |
7679 | const struct seq_operations *seq_ops; | |
345ddcc8 SRRH |
7680 | struct trace_array *tr = inode->i_private; |
7681 | struct seq_file *m; | |
756d17ee | 7682 | int ret = 0; |
7683 | ||
8530dec6 SRV |
7684 | ret = tracing_check_open_get_tr(tr); |
7685 | if (ret) | |
7686 | return ret; | |
345ddcc8 | 7687 | |
756d17ee | 7688 | if ((file->f_mode & FMODE_WRITE) && |
7689 | (file->f_flags & O_TRUNC)) | |
b3b1e6ed SRV |
7690 | ftrace_pid_reset(tr, type); |
7691 | ||
7692 | switch (type) { | |
7693 | case TRACE_PIDS: | |
7694 | seq_ops = &ftrace_pid_sops; | |
7695 | break; | |
7696 | case TRACE_NO_PIDS: | |
7697 | seq_ops = &ftrace_no_pid_sops; | |
7698 | break; | |
026bb845 KC |
7699 | default: |
7700 | trace_array_put(tr); | |
7701 | WARN_ON_ONCE(1); | |
7702 | return -EINVAL; | |
b3b1e6ed | 7703 | } |
756d17ee | 7704 | |
b3b1e6ed | 7705 | ret = seq_open(file, seq_ops); |
345ddcc8 SRRH |
7706 | if (ret < 0) { |
7707 | trace_array_put(tr); | |
7708 | } else { | |
7709 | m = file->private_data; | |
7710 | /* copy tr over to seq ops */ | |
7711 | m->private = tr; | |
7712 | } | |
756d17ee | 7713 | |
7714 | return ret; | |
7715 | } | |
7716 | ||
b3b1e6ed SRV |
7717 | static int |
7718 | ftrace_pid_open(struct inode *inode, struct file *file) | |
7719 | { | |
7720 | return pid_open(inode, file, TRACE_PIDS); | |
7721 | } | |
7722 | ||
7723 | static int | |
7724 | ftrace_no_pid_open(struct inode *inode, struct file *file) | |
7725 | { | |
7726 | return pid_open(inode, file, TRACE_NO_PIDS); | |
7727 | } | |
7728 | ||
345ddcc8 SRRH |
7729 | static void ignore_task_cpu(void *data) |
7730 | { | |
7731 | struct trace_array *tr = data; | |
7732 | struct trace_pid_list *pid_list; | |
b3b1e6ed | 7733 | struct trace_pid_list *no_pid_list; |
345ddcc8 SRRH |
7734 | |
7735 | /* | |
7736 | * This function is called by on_each_cpu() while the | |
7737 | * event_mutex is held. | |
7738 | */ | |
7739 | pid_list = rcu_dereference_protected(tr->function_pids, | |
7740 | mutex_is_locked(&ftrace_lock)); | |
b3b1e6ed SRV |
7741 | no_pid_list = rcu_dereference_protected(tr->function_no_pids, |
7742 | mutex_is_locked(&ftrace_lock)); | |
345ddcc8 | 7743 | |
b3b1e6ed | 7744 | if (trace_ignore_this_task(pid_list, no_pid_list, current)) |
717e3f5e SRV |
7745 | this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid, |
7746 | FTRACE_PID_IGNORE); | |
7747 | else | |
7748 | this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid, | |
7749 | current->pid); | |
345ddcc8 SRRH |
7750 | } |
7751 | ||
df4fc315 | 7752 | static ssize_t |
b3b1e6ed SRV |
7753 | pid_write(struct file *filp, const char __user *ubuf, |
7754 | size_t cnt, loff_t *ppos, int type) | |
df4fc315 | 7755 | { |
345ddcc8 SRRH |
7756 | struct seq_file *m = filp->private_data; |
7757 | struct trace_array *tr = m->private; | |
b3b1e6ed SRV |
7758 | struct trace_pid_list *filtered_pids; |
7759 | struct trace_pid_list *other_pids; | |
345ddcc8 SRRH |
7760 | struct trace_pid_list *pid_list; |
7761 | ssize_t ret; | |
df4fc315 | 7762 | |
345ddcc8 SRRH |
7763 | if (!cnt) |
7764 | return 0; | |
7765 | ||
7766 | mutex_lock(&ftrace_lock); | |
7767 | ||
b3b1e6ed SRV |
7768 | switch (type) { |
7769 | case TRACE_PIDS: | |
7770 | filtered_pids = rcu_dereference_protected(tr->function_pids, | |
345ddcc8 | 7771 | lockdep_is_held(&ftrace_lock)); |
b3b1e6ed SRV |
7772 | other_pids = rcu_dereference_protected(tr->function_no_pids, |
7773 | lockdep_is_held(&ftrace_lock)); | |
7774 | break; | |
7775 | case TRACE_NO_PIDS: | |
7776 | filtered_pids = rcu_dereference_protected(tr->function_no_pids, | |
7777 | lockdep_is_held(&ftrace_lock)); | |
7778 | other_pids = rcu_dereference_protected(tr->function_pids, | |
345ddcc8 | 7779 | lockdep_is_held(&ftrace_lock)); |
b3b1e6ed | 7780 | break; |
026bb845 KC |
7781 | default: |
7782 | ret = -EINVAL; | |
7783 | WARN_ON_ONCE(1); | |
7784 | goto out; | |
b3b1e6ed | 7785 | } |
345ddcc8 SRRH |
7786 | |
7787 | ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt); | |
7788 | if (ret < 0) | |
7789 | goto out; | |
df4fc315 | 7790 | |
b3b1e6ed SRV |
7791 | switch (type) { |
7792 | case TRACE_PIDS: | |
7793 | rcu_assign_pointer(tr->function_pids, pid_list); | |
7794 | break; | |
7795 | case TRACE_NO_PIDS: | |
7796 | rcu_assign_pointer(tr->function_no_pids, pid_list); | |
7797 | break; | |
7798 | } | |
7799 | ||
df4fc315 | 7800 | |
345ddcc8 | 7801 | if (filtered_pids) { |
74401729 | 7802 | synchronize_rcu(); |
6954e415 | 7803 | trace_pid_list_free(filtered_pids); |
b3b1e6ed | 7804 | } else if (pid_list && !other_pids) { |
345ddcc8 SRRH |
7805 | /* Register a probe to set whether to ignore the tracing of a task */ |
7806 | register_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr); | |
7807 | } | |
df4fc315 | 7808 | |
756d17ee | 7809 | /* |
345ddcc8 SRRH |
7810 | * Ignoring of pids is done at task switch. But we have to |
7811 | * check for those tasks that are currently running. | |
7812 | * Always do this in case a pid was appended or removed. | |
756d17ee | 7813 | */ |
345ddcc8 | 7814 | on_each_cpu(ignore_task_cpu, tr, 1); |
756d17ee | 7815 | |
345ddcc8 SRRH |
7816 | ftrace_update_pid_func(); |
7817 | ftrace_startup_all(0); | |
7818 | out: | |
7819 | mutex_unlock(&ftrace_lock); | |
df4fc315 | 7820 | |
345ddcc8 SRRH |
7821 | if (ret > 0) |
7822 | *ppos += ret; | |
df4fc315 | 7823 | |
345ddcc8 | 7824 | return ret; |
756d17ee | 7825 | } |
df4fc315 | 7826 | |
b3b1e6ed SRV |
7827 | static ssize_t |
7828 | ftrace_pid_write(struct file *filp, const char __user *ubuf, | |
7829 | size_t cnt, loff_t *ppos) | |
7830 | { | |
7831 | return pid_write(filp, ubuf, cnt, ppos, TRACE_PIDS); | |
7832 | } | |
7833 | ||
7834 | static ssize_t | |
7835 | ftrace_no_pid_write(struct file *filp, const char __user *ubuf, | |
7836 | size_t cnt, loff_t *ppos) | |
7837 | { | |
7838 | return pid_write(filp, ubuf, cnt, ppos, TRACE_NO_PIDS); | |
7839 | } | |
7840 | ||
756d17ee | 7841 | static int |
7842 | ftrace_pid_release(struct inode *inode, struct file *file) | |
7843 | { | |
345ddcc8 | 7844 | struct trace_array *tr = inode->i_private; |
df4fc315 | 7845 | |
345ddcc8 SRRH |
7846 | trace_array_put(tr); |
7847 | ||
7848 | return seq_release(inode, file); | |
df4fc315 SR |
7849 | } |
7850 | ||
5e2336a0 | 7851 | static const struct file_operations ftrace_pid_fops = { |
756d17ee | 7852 | .open = ftrace_pid_open, |
7853 | .write = ftrace_pid_write, | |
7854 | .read = seq_read, | |
098c879e | 7855 | .llseek = tracing_lseek, |
756d17ee | 7856 | .release = ftrace_pid_release, |
df4fc315 SR |
7857 | }; |
7858 | ||
b3b1e6ed SRV |
7859 | static const struct file_operations ftrace_no_pid_fops = { |
7860 | .open = ftrace_no_pid_open, | |
7861 | .write = ftrace_no_pid_write, | |
7862 | .read = seq_read, | |
7863 | .llseek = tracing_lseek, | |
7864 | .release = ftrace_pid_release, | |
7865 | }; | |
7866 | ||
345ddcc8 | 7867 | void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer) |
df4fc315 | 7868 | { |
21ccc9cd | 7869 | trace_create_file("set_ftrace_pid", TRACE_MODE_WRITE, d_tracer, |
345ddcc8 | 7870 | tr, &ftrace_pid_fops); |
21ccc9cd SRV |
7871 | trace_create_file("set_ftrace_notrace_pid", TRACE_MODE_WRITE, |
7872 | d_tracer, tr, &ftrace_no_pid_fops); | |
df4fc315 | 7873 | } |
df4fc315 | 7874 | |
501c2375 SRRH |
7875 | void __init ftrace_init_tracefs_toplevel(struct trace_array *tr, |
7876 | struct dentry *d_tracer) | |
7877 | { | |
7878 | /* Only the top level directory has the dyn_tracefs and profile */ | |
7879 | WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL)); | |
7880 | ||
7881 | ftrace_init_dyn_tracefs(d_tracer); | |
7882 | ftrace_profile_tracefs(d_tracer); | |
7883 | } | |
7884 | ||
a2bb6a3d | 7885 | /** |
81adbdc0 | 7886 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
7887 | * |
7888 | * This function should be used by panic code. It stops ftrace | |
7889 | * but in a not so nice way. If you need to simply kill ftrace | |
7890 | * from a non-atomic section, use ftrace_kill. | |
7891 | */ | |
81adbdc0 | 7892 | void ftrace_kill(void) |
a2bb6a3d SR |
7893 | { |
7894 | ftrace_disabled = 1; | |
7895 | ftrace_enabled = 0; | |
5ccba64a | 7896 | ftrace_trace_function = ftrace_stub; |
1a7d0890 | 7897 | kprobe_ftrace_kill(); |
a2bb6a3d SR |
7898 | } |
7899 | ||
e0a413f6 | 7900 | /** |
6130722f SRV |
7901 | * ftrace_is_dead - Test if ftrace is dead or not. |
7902 | * | |
d1530413 | 7903 | * Returns: 1 if ftrace is "dead", zero otherwise. |
e0a413f6 SR |
7904 | */ |
7905 | int ftrace_is_dead(void) | |
7906 | { | |
7907 | return ftrace_disabled; | |
7908 | } | |
7909 | ||
53cd885b SL |
7910 | #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS |
7911 | /* | |
7912 | * When registering ftrace_ops with IPMODIFY, it is necessary to make sure | |
7913 | * it doesn't conflict with any direct ftrace_ops. If there is existing | |
7914 | * direct ftrace_ops on a kernel function being patched, call | |
7915 | * FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_PEER on it to enable sharing. | |
7916 | * | |
7917 | * @ops: ftrace_ops being registered. | |
7918 | * | |
7919 | * Returns: | |
7920 | * 0 on success; | |
7921 | * Negative on failure. | |
7922 | */ | |
7923 | static int prepare_direct_functions_for_ipmodify(struct ftrace_ops *ops) | |
7924 | { | |
7925 | struct ftrace_func_entry *entry; | |
7926 | struct ftrace_hash *hash; | |
7927 | struct ftrace_ops *op; | |
7928 | int size, i, ret; | |
7929 | ||
7930 | lockdep_assert_held_once(&direct_mutex); | |
7931 | ||
7932 | if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY)) | |
7933 | return 0; | |
7934 | ||
7935 | hash = ops->func_hash->filter_hash; | |
7936 | size = 1 << hash->size_bits; | |
7937 | for (i = 0; i < size; i++) { | |
7938 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { | |
7939 | unsigned long ip = entry->ip; | |
7940 | bool found_op = false; | |
7941 | ||
7942 | mutex_lock(&ftrace_lock); | |
7943 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
7944 | if (!(op->flags & FTRACE_OPS_FL_DIRECT)) | |
7945 | continue; | |
7946 | if (ops_references_ip(op, ip)) { | |
7947 | found_op = true; | |
7948 | break; | |
7949 | } | |
7950 | } while_for_each_ftrace_op(op); | |
7951 | mutex_unlock(&ftrace_lock); | |
7952 | ||
7953 | if (found_op) { | |
7954 | if (!op->ops_func) | |
7955 | return -EBUSY; | |
7956 | ||
7957 | ret = op->ops_func(op, FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_PEER); | |
7958 | if (ret) | |
7959 | return ret; | |
7960 | } | |
7961 | } | |
7962 | } | |
7963 | ||
7964 | return 0; | |
7965 | } | |
7966 | ||
7967 | /* | |
7968 | * Similar to prepare_direct_functions_for_ipmodify, clean up after ops | |
7969 | * with IPMODIFY is unregistered. The cleanup is optional for most DIRECT | |
7970 | * ops. | |
7971 | */ | |
7972 | static void cleanup_direct_functions_after_ipmodify(struct ftrace_ops *ops) | |
7973 | { | |
7974 | struct ftrace_func_entry *entry; | |
7975 | struct ftrace_hash *hash; | |
7976 | struct ftrace_ops *op; | |
7977 | int size, i; | |
7978 | ||
7979 | if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY)) | |
7980 | return; | |
7981 | ||
7982 | mutex_lock(&direct_mutex); | |
7983 | ||
7984 | hash = ops->func_hash->filter_hash; | |
7985 | size = 1 << hash->size_bits; | |
7986 | for (i = 0; i < size; i++) { | |
7987 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { | |
7988 | unsigned long ip = entry->ip; | |
7989 | bool found_op = false; | |
7990 | ||
7991 | mutex_lock(&ftrace_lock); | |
7992 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
7993 | if (!(op->flags & FTRACE_OPS_FL_DIRECT)) | |
7994 | continue; | |
7995 | if (ops_references_ip(op, ip)) { | |
7996 | found_op = true; | |
7997 | break; | |
7998 | } | |
7999 | } while_for_each_ftrace_op(op); | |
8000 | mutex_unlock(&ftrace_lock); | |
8001 | ||
8002 | /* The cleanup is optional, ignore any errors */ | |
8003 | if (found_op && op->ops_func) | |
8004 | op->ops_func(op, FTRACE_OPS_CMD_DISABLE_SHARE_IPMODIFY_PEER); | |
8005 | } | |
8006 | } | |
8007 | mutex_unlock(&direct_mutex); | |
8008 | } | |
8009 | ||
8010 | #define lock_direct_mutex() mutex_lock(&direct_mutex) | |
8011 | #define unlock_direct_mutex() mutex_unlock(&direct_mutex) | |
8012 | ||
8013 | #else /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ | |
8014 | ||
8015 | static int prepare_direct_functions_for_ipmodify(struct ftrace_ops *ops) | |
8016 | { | |
8017 | return 0; | |
8018 | } | |
8019 | ||
8020 | static void cleanup_direct_functions_after_ipmodify(struct ftrace_ops *ops) | |
8021 | { | |
8022 | } | |
8023 | ||
8024 | #define lock_direct_mutex() do { } while (0) | |
8025 | #define unlock_direct_mutex() do { } while (0) | |
8026 | ||
8027 | #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ | |
8028 | ||
8029 | /* | |
8030 | * Similar to register_ftrace_function, except we don't lock direct_mutex. | |
8031 | */ | |
8032 | static int register_ftrace_function_nolock(struct ftrace_ops *ops) | |
8033 | { | |
8034 | int ret; | |
8035 | ||
8036 | ftrace_ops_init(ops); | |
8037 | ||
8038 | mutex_lock(&ftrace_lock); | |
8039 | ||
8040 | ret = ftrace_startup(ops, 0); | |
8041 | ||
8042 | mutex_unlock(&ftrace_lock); | |
8043 | ||
8044 | return ret; | |
8045 | } | |
8046 | ||
16444a8a | 8047 | /** |
3d083395 | 8048 | * register_ftrace_function - register a function for profiling |
78cbc651 | 8049 | * @ops: ops structure that holds the function for profiling. |
16444a8a | 8050 | * |
3d083395 SR |
8051 | * Register a function to be called by all functions in the |
8052 | * kernel. | |
8053 | * | |
8054 | * Note: @ops->func and all the functions it calls must be labeled | |
8055 | * with "notrace", otherwise it will go into a | |
8056 | * recursive loop. | |
16444a8a | 8057 | */ |
3d083395 | 8058 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 8059 | { |
3b1a8f45 | 8060 | int ret; |
4eebcc81 | 8061 | |
53cd885b SL |
8062 | lock_direct_mutex(); |
8063 | ret = prepare_direct_functions_for_ipmodify(ops); | |
8064 | if (ret < 0) | |
8065 | goto out_unlock; | |
b848914c | 8066 | |
53cd885b | 8067 | ret = register_ftrace_function_nolock(ops); |
8d240dd8 | 8068 | |
53cd885b SL |
8069 | out_unlock: |
8070 | unlock_direct_mutex(); | |
b0fc494f | 8071 | return ret; |
3d083395 | 8072 | } |
cdbe61bf | 8073 | EXPORT_SYMBOL_GPL(register_ftrace_function); |
3d083395 SR |
8074 | |
8075 | /** | |
32632920 | 8076 | * unregister_ftrace_function - unregister a function for profiling. |
78cbc651 | 8077 | * @ops: ops structure that holds the function to unregister |
3d083395 SR |
8078 | * |
8079 | * Unregister a function that was added to be called by ftrace profiling. | |
8080 | */ | |
8081 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
8082 | { | |
8083 | int ret; | |
8084 | ||
e6ea44e9 | 8085 | mutex_lock(&ftrace_lock); |
8a56d776 | 8086 | ret = ftrace_shutdown(ops, 0); |
e6ea44e9 | 8087 | mutex_unlock(&ftrace_lock); |
b0fc494f | 8088 | |
53cd885b | 8089 | cleanup_direct_functions_after_ipmodify(ops); |
b0fc494f SR |
8090 | return ret; |
8091 | } | |
cdbe61bf | 8092 | EXPORT_SYMBOL_GPL(unregister_ftrace_function); |
b0fc494f | 8093 | |
bed0d9a5 JO |
8094 | static int symbols_cmp(const void *a, const void *b) |
8095 | { | |
8096 | const char **str_a = (const char **) a; | |
8097 | const char **str_b = (const char **) b; | |
8098 | ||
8099 | return strcmp(*str_a, *str_b); | |
8100 | } | |
8101 | ||
8102 | struct kallsyms_data { | |
8103 | unsigned long *addrs; | |
8104 | const char **syms; | |
8105 | size_t cnt; | |
8106 | size_t found; | |
8107 | }; | |
8108 | ||
3640bf85 JO |
8109 | /* This function gets called for all kernel and module symbols |
8110 | * and returns 1 in case we resolved all the requested symbols, | |
8111 | * 0 otherwise. | |
8112 | */ | |
3703bd54 | 8113 | static int kallsyms_callback(void *data, const char *name, unsigned long addr) |
bed0d9a5 JO |
8114 | { |
8115 | struct kallsyms_data *args = data; | |
eb1b2985 JO |
8116 | const char **sym; |
8117 | int idx; | |
bed0d9a5 | 8118 | |
eb1b2985 JO |
8119 | sym = bsearch(&name, args->syms, args->cnt, sizeof(*args->syms), symbols_cmp); |
8120 | if (!sym) | |
8121 | return 0; | |
8122 | ||
8123 | idx = sym - args->syms; | |
8124 | if (args->addrs[idx]) | |
bed0d9a5 JO |
8125 | return 0; |
8126 | ||
9d68c19c | 8127 | if (!ftrace_location(addr)) |
bed0d9a5 JO |
8128 | return 0; |
8129 | ||
eb1b2985 JO |
8130 | args->addrs[idx] = addr; |
8131 | args->found++; | |
bed0d9a5 JO |
8132 | return args->found == args->cnt ? 1 : 0; |
8133 | } | |
8134 | ||
8135 | /** | |
8136 | * ftrace_lookup_symbols - Lookup addresses for array of symbols | |
8137 | * | |
8138 | * @sorted_syms: array of symbols pointers symbols to resolve, | |
8139 | * must be alphabetically sorted | |
8140 | * @cnt: number of symbols/addresses in @syms/@addrs arrays | |
8141 | * @addrs: array for storing resulting addresses | |
8142 | * | |
8143 | * This function looks up addresses for array of symbols provided in | |
8144 | * @syms array (must be alphabetically sorted) and stores them in | |
8145 | * @addrs array, which needs to be big enough to store at least @cnt | |
8146 | * addresses. | |
8147 | * | |
d1530413 | 8148 | * Returns: 0 if all provided symbols are found, -ESRCH otherwise. |
bed0d9a5 JO |
8149 | */ |
8150 | int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *addrs) | |
8151 | { | |
8152 | struct kallsyms_data args; | |
3640bf85 | 8153 | int found_all; |
bed0d9a5 | 8154 | |
eb1b2985 | 8155 | memset(addrs, 0, sizeof(*addrs) * cnt); |
bed0d9a5 JO |
8156 | args.addrs = addrs; |
8157 | args.syms = sorted_syms; | |
8158 | args.cnt = cnt; | |
8159 | args.found = 0; | |
3640bf85 JO |
8160 | |
8161 | found_all = kallsyms_on_each_symbol(kallsyms_callback, &args); | |
8162 | if (found_all) | |
8163 | return 0; | |
07cc2c93 | 8164 | found_all = module_kallsyms_on_each_symbol(NULL, kallsyms_callback, &args); |
3640bf85 | 8165 | return found_all ? 0 : -ESRCH; |
bed0d9a5 | 8166 | } |
44d35720 | 8167 | |
5d79fa0d | 8168 | #ifdef CONFIG_SYSCTL |
8fd7c214 LC |
8169 | |
8170 | #ifdef CONFIG_DYNAMIC_FTRACE | |
f8b7d2b4 LC |
8171 | static void ftrace_startup_sysctl(void) |
8172 | { | |
8173 | int command; | |
8174 | ||
8175 | if (unlikely(ftrace_disabled)) | |
8176 | return; | |
8177 | ||
8178 | /* Force update next time */ | |
8179 | saved_ftrace_func = NULL; | |
8180 | /* ftrace_start_up is true if we want ftrace running */ | |
8181 | if (ftrace_start_up) { | |
8182 | command = FTRACE_UPDATE_CALLS; | |
8183 | if (ftrace_graph_active) | |
8184 | command |= FTRACE_START_FUNC_RET; | |
8185 | ftrace_startup_enable(command); | |
8186 | } | |
8187 | } | |
8188 | ||
8189 | static void ftrace_shutdown_sysctl(void) | |
8190 | { | |
8191 | int command; | |
8192 | ||
8193 | if (unlikely(ftrace_disabled)) | |
8194 | return; | |
8195 | ||
8196 | /* ftrace_start_up is true if ftrace is running */ | |
8197 | if (ftrace_start_up) { | |
8198 | command = FTRACE_DISABLE_CALLS; | |
8199 | if (ftrace_graph_active) | |
8200 | command |= FTRACE_STOP_FUNC_RET; | |
8201 | ftrace_run_update_code(command); | |
8202 | } | |
8203 | } | |
8fd7c214 LC |
8204 | #else |
8205 | # define ftrace_startup_sysctl() do { } while (0) | |
8206 | # define ftrace_shutdown_sysctl() do { } while (0) | |
8207 | #endif /* CONFIG_DYNAMIC_FTRACE */ | |
f8b7d2b4 | 8208 | |
7162431d MB |
8209 | static bool is_permanent_ops_registered(void) |
8210 | { | |
8211 | struct ftrace_ops *op; | |
8212 | ||
8213 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
8214 | if (op->flags & FTRACE_OPS_FL_PERMANENT) | |
8215 | return true; | |
8216 | } while_for_each_ftrace_op(op); | |
8217 | ||
8218 | return false; | |
8219 | } | |
8220 | ||
8e4e83b2 | 8221 | static int |
b0fc494f | 8222 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
54fa9ba5 | 8223 | void *buffer, size_t *lenp, loff_t *ppos) |
b0fc494f | 8224 | { |
45a4a237 | 8225 | int ret = -ENODEV; |
4eebcc81 | 8226 | |
e6ea44e9 | 8227 | mutex_lock(&ftrace_lock); |
b0fc494f | 8228 | |
45a4a237 SR |
8229 | if (unlikely(ftrace_disabled)) |
8230 | goto out; | |
8231 | ||
8232 | ret = proc_dointvec(table, write, buffer, lenp, ppos); | |
b0fc494f | 8233 | |
a32c7765 | 8234 | if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled)) |
b0fc494f SR |
8235 | goto out; |
8236 | ||
b0fc494f SR |
8237 | if (ftrace_enabled) { |
8238 | ||
b0fc494f | 8239 | /* we are starting ftrace again */ |
f86f4180 CZ |
8240 | if (rcu_dereference_protected(ftrace_ops_list, |
8241 | lockdep_is_held(&ftrace_lock)) != &ftrace_list_end) | |
5000c418 | 8242 | update_ftrace_function(); |
b0fc494f | 8243 | |
524a3868 SRRH |
8244 | ftrace_startup_sysctl(); |
8245 | ||
b0fc494f | 8246 | } else { |
7162431d MB |
8247 | if (is_permanent_ops_registered()) { |
8248 | ftrace_enabled = true; | |
8249 | ret = -EBUSY; | |
8250 | goto out; | |
8251 | } | |
8252 | ||
b0fc494f SR |
8253 | /* stopping ftrace calls (just send to ftrace_stub) */ |
8254 | ftrace_trace_function = ftrace_stub; | |
8255 | ||
8256 | ftrace_shutdown_sysctl(); | |
8257 | } | |
8258 | ||
7162431d | 8259 | last_ftrace_enabled = !!ftrace_enabled; |
b0fc494f | 8260 | out: |
e6ea44e9 | 8261 | mutex_unlock(&ftrace_lock); |
3d083395 | 8262 | return ret; |
16444a8a | 8263 | } |
8e4e83b2 WX |
8264 | |
8265 | static struct ctl_table ftrace_sysctls[] = { | |
8266 | { | |
8267 | .procname = "ftrace_enabled", | |
8268 | .data = &ftrace_enabled, | |
8269 | .maxlen = sizeof(int), | |
8270 | .mode = 0644, | |
8271 | .proc_handler = ftrace_enable_sysctl, | |
8272 | }, | |
8e4e83b2 WX |
8273 | }; |
8274 | ||
8275 | static int __init ftrace_sysctl_init(void) | |
8276 | { | |
8277 | register_sysctl_init("kernel", ftrace_sysctls); | |
8278 | return 0; | |
8279 | } | |
8280 | late_initcall(ftrace_sysctl_init); | |
8281 | #endif |