2 * Infrastructure for profiling code inserted by 'gcc -pg'.
4 * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
5 * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com>
7 * Originally ported from the -rt patch by:
8 * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com>
10 * Based on code in the latency_tracer, that is:
12 * Copyright (C) 2004-2006 Ingo Molnar
13 * Copyright (C) 2004 Nadia Yvette Chambers
16 #include <linux/stop_machine.h>
17 #include <linux/clocksource.h>
18 #include <linux/sched/task.h>
19 #include <linux/kallsyms.h>
20 #include <linux/seq_file.h>
21 #include <linux/suspend.h>
22 #include <linux/tracefs.h>
23 #include <linux/hardirq.h>
24 #include <linux/kthread.h>
25 #include <linux/uaccess.h>
26 #include <linux/bsearch.h>
27 #include <linux/module.h>
28 #include <linux/ftrace.h>
29 #include <linux/sysctl.h>
30 #include <linux/slab.h>
31 #include <linux/ctype.h>
32 #include <linux/sort.h>
33 #include <linux/list.h>
34 #include <linux/hash.h>
35 #include <linux/rcupdate.h>
37 #include <trace/events/sched.h>
39 #include <asm/sections.h>
40 #include <asm/setup.h>
42 #include "trace_output.h"
43 #include "trace_stat.h"
45 #define FTRACE_WARN_ON(cond) \
53 #define FTRACE_WARN_ON_ONCE(cond) \
56 if (WARN_ON_ONCE(___r)) \
61 /* hash bits for specific function selection */
62 #define FTRACE_HASH_BITS 7
63 #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS)
64 #define FTRACE_HASH_DEFAULT_BITS 10
65 #define FTRACE_HASH_MAX_BITS 12
67 #ifdef CONFIG_DYNAMIC_FTRACE
68 #define INIT_OPS_HASH(opsname) \
69 .func_hash = &opsname.local_hash, \
70 .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock),
71 #define ASSIGN_OPS_HASH(opsname, val) \
73 .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock),
75 #define INIT_OPS_HASH(opsname)
76 #define ASSIGN_OPS_HASH(opsname, val)
79 static struct ftrace_ops ftrace_list_end __read_mostly
= {
81 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
| FTRACE_OPS_FL_STUB
,
82 INIT_OPS_HASH(ftrace_list_end
)
85 /* ftrace_enabled is a method to turn ftrace on or off */
86 int ftrace_enabled __read_mostly
;
87 static int last_ftrace_enabled
;
89 /* Current function tracing op */
90 struct ftrace_ops
*function_trace_op __read_mostly
= &ftrace_list_end
;
91 /* What to set function_trace_op to */
92 static struct ftrace_ops
*set_function_trace_op
;
94 static bool ftrace_pids_enabled(struct ftrace_ops
*ops
)
96 struct trace_array
*tr
;
98 if (!(ops
->flags
& FTRACE_OPS_FL_PID
) || !ops
->private)
103 return tr
->function_pids
!= NULL
;
106 static void ftrace_update_trampoline(struct ftrace_ops
*ops
);
109 * ftrace_disabled is set when an anomaly is discovered.
110 * ftrace_disabled is much stronger than ftrace_enabled.
112 static int ftrace_disabled __read_mostly
;
114 static DEFINE_MUTEX(ftrace_lock
);
116 static struct ftrace_ops __rcu
*ftrace_ops_list __read_mostly
= &ftrace_list_end
;
117 ftrace_func_t ftrace_trace_function __read_mostly
= ftrace_stub
;
118 static struct ftrace_ops global_ops
;
120 #if ARCH_SUPPORTS_FTRACE_OPS
121 static void ftrace_ops_list_func(unsigned long ip
, unsigned long parent_ip
,
122 struct ftrace_ops
*op
, struct pt_regs
*regs
);
124 /* See comment below, where ftrace_ops_list_func is defined */
125 static void ftrace_ops_no_ops(unsigned long ip
, unsigned long parent_ip
);
126 #define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops)
130 * Traverse the ftrace_global_list, invoking all entries. The reason that we
131 * can use rcu_dereference_raw_notrace() is that elements removed from this list
132 * are simply leaked, so there is no need to interact with a grace-period
133 * mechanism. The rcu_dereference_raw_notrace() calls are needed to handle
134 * concurrent insertions into the ftrace_global_list.
136 * Silly Alpha and silly pointer-speculation compiler optimizations!
138 #define do_for_each_ftrace_op(op, list) \
139 op = rcu_dereference_raw_notrace(list); \
143 * Optimized for just a single item in the list (as that is the normal case).
145 #define while_for_each_ftrace_op(op) \
146 while (likely(op = rcu_dereference_raw_notrace((op)->next)) && \
147 unlikely((op) != &ftrace_list_end))
149 static inline void ftrace_ops_init(struct ftrace_ops
*ops
)
151 #ifdef CONFIG_DYNAMIC_FTRACE
152 if (!(ops
->flags
& FTRACE_OPS_FL_INITIALIZED
)) {
153 mutex_init(&ops
->local_hash
.regex_lock
);
154 ops
->func_hash
= &ops
->local_hash
;
155 ops
->flags
|= FTRACE_OPS_FL_INITIALIZED
;
161 * ftrace_nr_registered_ops - return number of ops registered
163 * Returns the number of ftrace_ops registered and tracing functions
165 int ftrace_nr_registered_ops(void)
167 struct ftrace_ops
*ops
;
170 mutex_lock(&ftrace_lock
);
172 for (ops
= rcu_dereference_protected(ftrace_ops_list
,
173 lockdep_is_held(&ftrace_lock
));
174 ops
!= &ftrace_list_end
;
175 ops
= rcu_dereference_protected(ops
->next
,
176 lockdep_is_held(&ftrace_lock
)))
179 mutex_unlock(&ftrace_lock
);
184 static void ftrace_pid_func(unsigned long ip
, unsigned long parent_ip
,
185 struct ftrace_ops
*op
, struct pt_regs
*regs
)
187 struct trace_array
*tr
= op
->private;
189 if (tr
&& this_cpu_read(tr
->trace_buffer
.data
->ftrace_ignore_pid
))
192 op
->saved_func(ip
, parent_ip
, op
, regs
);
196 * clear_ftrace_function - reset the ftrace function
198 * This NULLs the ftrace function and in essence stops
199 * tracing. There may be lag
201 void clear_ftrace_function(void)
203 ftrace_trace_function
= ftrace_stub
;
206 static void per_cpu_ops_disable_all(struct ftrace_ops
*ops
)
210 for_each_possible_cpu(cpu
)
211 *per_cpu_ptr(ops
->disabled
, cpu
) = 1;
214 static int per_cpu_ops_alloc(struct ftrace_ops
*ops
)
216 int __percpu
*disabled
;
218 if (WARN_ON_ONCE(!(ops
->flags
& FTRACE_OPS_FL_PER_CPU
)))
221 disabled
= alloc_percpu(int);
225 ops
->disabled
= disabled
;
226 per_cpu_ops_disable_all(ops
);
230 static void ftrace_sync(struct work_struct
*work
)
233 * This function is just a stub to implement a hard force
234 * of synchronize_sched(). This requires synchronizing
235 * tasks even in userspace and idle.
237 * Yes, function tracing is rude.
241 static void ftrace_sync_ipi(void *data
)
243 /* Probably not needed, but do it anyway */
247 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
248 static void update_function_graph_func(void);
250 /* Both enabled by default (can be cleared by function_graph tracer flags */
251 static bool fgraph_sleep_time
= true;
252 static bool fgraph_graph_time
= true;
255 static inline void update_function_graph_func(void) { }
259 static ftrace_func_t
ftrace_ops_get_list_func(struct ftrace_ops
*ops
)
262 * If this is a dynamic, RCU, or per CPU ops, or we force list func,
263 * then it needs to call the list anyway.
265 if (ops
->flags
& (FTRACE_OPS_FL_DYNAMIC
| FTRACE_OPS_FL_PER_CPU
|
266 FTRACE_OPS_FL_RCU
) || FTRACE_FORCE_LIST_FUNC
)
267 return ftrace_ops_list_func
;
269 return ftrace_ops_get_func(ops
);
272 static void update_ftrace_function(void)
277 * Prepare the ftrace_ops that the arch callback will use.
278 * If there's only one ftrace_ops registered, the ftrace_ops_list
279 * will point to the ops we want.
281 set_function_trace_op
= rcu_dereference_protected(ftrace_ops_list
,
282 lockdep_is_held(&ftrace_lock
));
284 /* If there's no ftrace_ops registered, just call the stub function */
285 if (set_function_trace_op
== &ftrace_list_end
) {
289 * If we are at the end of the list and this ops is
290 * recursion safe and not dynamic and the arch supports passing ops,
291 * then have the mcount trampoline call the function directly.
293 } else if (rcu_dereference_protected(ftrace_ops_list
->next
,
294 lockdep_is_held(&ftrace_lock
)) == &ftrace_list_end
) {
295 func
= ftrace_ops_get_list_func(ftrace_ops_list
);
298 /* Just use the default ftrace_ops */
299 set_function_trace_op
= &ftrace_list_end
;
300 func
= ftrace_ops_list_func
;
303 update_function_graph_func();
305 /* If there's no change, then do nothing more here */
306 if (ftrace_trace_function
== func
)
310 * If we are using the list function, it doesn't care
311 * about the function_trace_ops.
313 if (func
== ftrace_ops_list_func
) {
314 ftrace_trace_function
= func
;
316 * Don't even bother setting function_trace_ops,
317 * it would be racy to do so anyway.
322 #ifndef CONFIG_DYNAMIC_FTRACE
324 * For static tracing, we need to be a bit more careful.
325 * The function change takes affect immediately. Thus,
326 * we need to coorditate the setting of the function_trace_ops
327 * with the setting of the ftrace_trace_function.
329 * Set the function to the list ops, which will call the
330 * function we want, albeit indirectly, but it handles the
331 * ftrace_ops and doesn't depend on function_trace_op.
333 ftrace_trace_function
= ftrace_ops_list_func
;
335 * Make sure all CPUs see this. Yes this is slow, but static
336 * tracing is slow and nasty to have enabled.
338 schedule_on_each_cpu(ftrace_sync
);
339 /* Now all cpus are using the list ops. */
340 function_trace_op
= set_function_trace_op
;
341 /* Make sure the function_trace_op is visible on all CPUs */
343 /* Nasty way to force a rmb on all cpus */
344 smp_call_function(ftrace_sync_ipi
, NULL
, 1);
345 /* OK, we are all set to update the ftrace_trace_function now! */
346 #endif /* !CONFIG_DYNAMIC_FTRACE */
348 ftrace_trace_function
= func
;
351 int using_ftrace_ops_list_func(void)
353 return ftrace_trace_function
== ftrace_ops_list_func
;
356 static void add_ftrace_ops(struct ftrace_ops __rcu
**list
,
357 struct ftrace_ops
*ops
)
359 rcu_assign_pointer(ops
->next
, *list
);
362 * We are entering ops into the list but another
363 * CPU might be walking that list. We need to make sure
364 * the ops->next pointer is valid before another CPU sees
365 * the ops pointer included into the list.
367 rcu_assign_pointer(*list
, ops
);
370 static int remove_ftrace_ops(struct ftrace_ops __rcu
**list
,
371 struct ftrace_ops
*ops
)
373 struct ftrace_ops
**p
;
376 * If we are removing the last function, then simply point
377 * to the ftrace_stub.
379 if (rcu_dereference_protected(*list
,
380 lockdep_is_held(&ftrace_lock
)) == ops
&&
381 rcu_dereference_protected(ops
->next
,
382 lockdep_is_held(&ftrace_lock
)) == &ftrace_list_end
) {
383 *list
= &ftrace_list_end
;
387 for (p
= list
; *p
!= &ftrace_list_end
; p
= &(*p
)->next
)
398 static void ftrace_update_trampoline(struct ftrace_ops
*ops
);
400 static int __register_ftrace_function(struct ftrace_ops
*ops
)
402 if (ops
->flags
& FTRACE_OPS_FL_DELETED
)
405 if (WARN_ON(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
408 #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
410 * If the ftrace_ops specifies SAVE_REGS, then it only can be used
411 * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set.
412 * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant.
414 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
&&
415 !(ops
->flags
& FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED
))
418 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED
)
419 ops
->flags
|= FTRACE_OPS_FL_SAVE_REGS
;
422 if (!core_kernel_data((unsigned long)ops
))
423 ops
->flags
|= FTRACE_OPS_FL_DYNAMIC
;
425 if (ops
->flags
& FTRACE_OPS_FL_PER_CPU
) {
426 if (per_cpu_ops_alloc(ops
))
430 add_ftrace_ops(&ftrace_ops_list
, ops
);
432 /* Always save the function, and reset at unregistering */
433 ops
->saved_func
= ops
->func
;
435 if (ftrace_pids_enabled(ops
))
436 ops
->func
= ftrace_pid_func
;
438 ftrace_update_trampoline(ops
);
441 update_ftrace_function();
446 static int __unregister_ftrace_function(struct ftrace_ops
*ops
)
450 if (WARN_ON(!(ops
->flags
& FTRACE_OPS_FL_ENABLED
)))
453 ret
= remove_ftrace_ops(&ftrace_ops_list
, ops
);
459 update_ftrace_function();
461 ops
->func
= ops
->saved_func
;
466 static void ftrace_update_pid_func(void)
468 struct ftrace_ops
*op
;
470 /* Only do something if we are tracing something */
471 if (ftrace_trace_function
== ftrace_stub
)
474 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
475 if (op
->flags
& FTRACE_OPS_FL_PID
) {
476 op
->func
= ftrace_pids_enabled(op
) ?
477 ftrace_pid_func
: op
->saved_func
;
478 ftrace_update_trampoline(op
);
480 } while_for_each_ftrace_op(op
);
482 update_ftrace_function();
485 #ifdef CONFIG_FUNCTION_PROFILER
486 struct ftrace_profile
{
487 struct hlist_node node
;
489 unsigned long counter
;
490 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
491 unsigned long long time
;
492 unsigned long long time_squared
;
496 struct ftrace_profile_page
{
497 struct ftrace_profile_page
*next
;
499 struct ftrace_profile records
[];
502 struct ftrace_profile_stat
{
504 struct hlist_head
*hash
;
505 struct ftrace_profile_page
*pages
;
506 struct ftrace_profile_page
*start
;
507 struct tracer_stat stat
;
510 #define PROFILE_RECORDS_SIZE \
511 (PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
513 #define PROFILES_PER_PAGE \
514 (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
516 static int ftrace_profile_enabled __read_mostly
;
518 /* ftrace_profile_lock - synchronize the enable and disable of the profiler */
519 static DEFINE_MUTEX(ftrace_profile_lock
);
521 static DEFINE_PER_CPU(struct ftrace_profile_stat
, ftrace_profile_stats
);
523 #define FTRACE_PROFILE_HASH_BITS 10
524 #define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS)
527 function_stat_next(void *v
, int idx
)
529 struct ftrace_profile
*rec
= v
;
530 struct ftrace_profile_page
*pg
;
532 pg
= (struct ftrace_profile_page
*)((unsigned long)rec
& PAGE_MASK
);
538 if ((void *)rec
>= (void *)&pg
->records
[pg
->index
]) {
542 rec
= &pg
->records
[0];
550 static void *function_stat_start(struct tracer_stat
*trace
)
552 struct ftrace_profile_stat
*stat
=
553 container_of(trace
, struct ftrace_profile_stat
, stat
);
555 if (!stat
|| !stat
->start
)
558 return function_stat_next(&stat
->start
->records
[0], 0);
561 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
562 /* function graph compares on total time */
563 static int function_stat_cmp(void *p1
, void *p2
)
565 struct ftrace_profile
*a
= p1
;
566 struct ftrace_profile
*b
= p2
;
568 if (a
->time
< b
->time
)
570 if (a
->time
> b
->time
)
576 /* not function graph compares against hits */
577 static int function_stat_cmp(void *p1
, void *p2
)
579 struct ftrace_profile
*a
= p1
;
580 struct ftrace_profile
*b
= p2
;
582 if (a
->counter
< b
->counter
)
584 if (a
->counter
> b
->counter
)
591 static int function_stat_headers(struct seq_file
*m
)
593 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
594 seq_puts(m
, " Function "
597 "--- ---- --- ---\n");
599 seq_puts(m
, " Function Hit\n"
605 static int function_stat_show(struct seq_file
*m
, void *v
)
607 struct ftrace_profile
*rec
= v
;
608 char str
[KSYM_SYMBOL_LEN
];
610 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
611 static struct trace_seq s
;
612 unsigned long long avg
;
613 unsigned long long stddev
;
615 mutex_lock(&ftrace_profile_lock
);
617 /* we raced with function_profile_reset() */
618 if (unlikely(rec
->counter
== 0)) {
623 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
625 do_div(avg
, rec
->counter
);
626 if (tracing_thresh
&& (avg
< tracing_thresh
))
630 kallsyms_lookup(rec
->ip
, NULL
, NULL
, NULL
, str
);
631 seq_printf(m
, " %-30.30s %10lu", str
, rec
->counter
);
633 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
636 /* Sample standard deviation (s^2) */
637 if (rec
->counter
<= 1)
641 * Apply Welford's method:
642 * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2)
644 stddev
= rec
->counter
* rec
->time_squared
-
645 rec
->time
* rec
->time
;
648 * Divide only 1000 for ns^2 -> us^2 conversion.
649 * trace_print_graph_duration will divide 1000 again.
651 do_div(stddev
, rec
->counter
* (rec
->counter
- 1) * 1000);
655 trace_print_graph_duration(rec
->time
, &s
);
656 trace_seq_puts(&s
, " ");
657 trace_print_graph_duration(avg
, &s
);
658 trace_seq_puts(&s
, " ");
659 trace_print_graph_duration(stddev
, &s
);
660 trace_print_seq(m
, &s
);
664 mutex_unlock(&ftrace_profile_lock
);
669 static void ftrace_profile_reset(struct ftrace_profile_stat
*stat
)
671 struct ftrace_profile_page
*pg
;
673 pg
= stat
->pages
= stat
->start
;
676 memset(pg
->records
, 0, PROFILE_RECORDS_SIZE
);
681 memset(stat
->hash
, 0,
682 FTRACE_PROFILE_HASH_SIZE
* sizeof(struct hlist_head
));
685 int ftrace_profile_pages_init(struct ftrace_profile_stat
*stat
)
687 struct ftrace_profile_page
*pg
;
692 /* If we already allocated, do nothing */
696 stat
->pages
= (void *)get_zeroed_page(GFP_KERNEL
);
700 #ifdef CONFIG_DYNAMIC_FTRACE
701 functions
= ftrace_update_tot_cnt
;
704 * We do not know the number of functions that exist because
705 * dynamic tracing is what counts them. With past experience
706 * we have around 20K functions. That should be more than enough.
707 * It is highly unlikely we will execute every function in
713 pg
= stat
->start
= stat
->pages
;
715 pages
= DIV_ROUND_UP(functions
, PROFILES_PER_PAGE
);
717 for (i
= 1; i
< pages
; i
++) {
718 pg
->next
= (void *)get_zeroed_page(GFP_KERNEL
);
729 unsigned long tmp
= (unsigned long)pg
;
741 static int ftrace_profile_init_cpu(int cpu
)
743 struct ftrace_profile_stat
*stat
;
746 stat
= &per_cpu(ftrace_profile_stats
, cpu
);
749 /* If the profile is already created, simply reset it */
750 ftrace_profile_reset(stat
);
755 * We are profiling all functions, but usually only a few thousand
756 * functions are hit. We'll make a hash of 1024 items.
758 size
= FTRACE_PROFILE_HASH_SIZE
;
760 stat
->hash
= kzalloc(sizeof(struct hlist_head
) * size
, GFP_KERNEL
);
765 /* Preallocate the function profiling pages */
766 if (ftrace_profile_pages_init(stat
) < 0) {
775 static int ftrace_profile_init(void)
780 for_each_possible_cpu(cpu
) {
781 ret
= ftrace_profile_init_cpu(cpu
);
789 /* interrupts must be disabled */
790 static struct ftrace_profile
*
791 ftrace_find_profiled_func(struct ftrace_profile_stat
*stat
, unsigned long ip
)
793 struct ftrace_profile
*rec
;
794 struct hlist_head
*hhd
;
797 key
= hash_long(ip
, FTRACE_PROFILE_HASH_BITS
);
798 hhd
= &stat
->hash
[key
];
800 if (hlist_empty(hhd
))
803 hlist_for_each_entry_rcu_notrace(rec
, hhd
, node
) {
811 static void ftrace_add_profile(struct ftrace_profile_stat
*stat
,
812 struct ftrace_profile
*rec
)
816 key
= hash_long(rec
->ip
, FTRACE_PROFILE_HASH_BITS
);
817 hlist_add_head_rcu(&rec
->node
, &stat
->hash
[key
]);
821 * The memory is already allocated, this simply finds a new record to use.
823 static struct ftrace_profile
*
824 ftrace_profile_alloc(struct ftrace_profile_stat
*stat
, unsigned long ip
)
826 struct ftrace_profile
*rec
= NULL
;
828 /* prevent recursion (from NMIs) */
829 if (atomic_inc_return(&stat
->disabled
) != 1)
833 * Try to find the function again since an NMI
834 * could have added it
836 rec
= ftrace_find_profiled_func(stat
, ip
);
840 if (stat
->pages
->index
== PROFILES_PER_PAGE
) {
841 if (!stat
->pages
->next
)
843 stat
->pages
= stat
->pages
->next
;
846 rec
= &stat
->pages
->records
[stat
->pages
->index
++];
848 ftrace_add_profile(stat
, rec
);
851 atomic_dec(&stat
->disabled
);
857 function_profile_call(unsigned long ip
, unsigned long parent_ip
,
858 struct ftrace_ops
*ops
, struct pt_regs
*regs
)
860 struct ftrace_profile_stat
*stat
;
861 struct ftrace_profile
*rec
;
864 if (!ftrace_profile_enabled
)
867 local_irq_save(flags
);
869 stat
= this_cpu_ptr(&ftrace_profile_stats
);
870 if (!stat
->hash
|| !ftrace_profile_enabled
)
873 rec
= ftrace_find_profiled_func(stat
, ip
);
875 rec
= ftrace_profile_alloc(stat
, ip
);
882 local_irq_restore(flags
);
885 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
886 static int profile_graph_entry(struct ftrace_graph_ent
*trace
)
888 int index
= trace
->depth
;
890 function_profile_call(trace
->func
, 0, NULL
, NULL
);
892 /* If function graph is shutting down, ret_stack can be NULL */
893 if (!current
->ret_stack
)
896 if (index
>= 0 && index
< FTRACE_RETFUNC_DEPTH
)
897 current
->ret_stack
[index
].subtime
= 0;
902 static void profile_graph_return(struct ftrace_graph_ret
*trace
)
904 struct ftrace_profile_stat
*stat
;
905 unsigned long long calltime
;
906 struct ftrace_profile
*rec
;
909 local_irq_save(flags
);
910 stat
= this_cpu_ptr(&ftrace_profile_stats
);
911 if (!stat
->hash
|| !ftrace_profile_enabled
)
914 /* If the calltime was zero'd ignore it */
915 if (!trace
->calltime
)
918 calltime
= trace
->rettime
- trace
->calltime
;
920 if (!fgraph_graph_time
) {
923 index
= trace
->depth
;
925 /* Append this call time to the parent time to subtract */
927 current
->ret_stack
[index
- 1].subtime
+= calltime
;
929 if (current
->ret_stack
[index
].subtime
< calltime
)
930 calltime
-= current
->ret_stack
[index
].subtime
;
935 rec
= ftrace_find_profiled_func(stat
, trace
->func
);
937 rec
->time
+= calltime
;
938 rec
->time_squared
+= calltime
* calltime
;
942 local_irq_restore(flags
);
945 static int register_ftrace_profiler(void)
947 return register_ftrace_graph(&profile_graph_return
,
948 &profile_graph_entry
);
951 static void unregister_ftrace_profiler(void)
953 unregister_ftrace_graph();
956 static struct ftrace_ops ftrace_profile_ops __read_mostly
= {
957 .func
= function_profile_call
,
958 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
| FTRACE_OPS_FL_INITIALIZED
,
959 INIT_OPS_HASH(ftrace_profile_ops
)
962 static int register_ftrace_profiler(void)
964 return register_ftrace_function(&ftrace_profile_ops
);
967 static void unregister_ftrace_profiler(void)
969 unregister_ftrace_function(&ftrace_profile_ops
);
971 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
974 ftrace_profile_write(struct file
*filp
, const char __user
*ubuf
,
975 size_t cnt
, loff_t
*ppos
)
980 ret
= kstrtoul_from_user(ubuf
, cnt
, 10, &val
);
986 mutex_lock(&ftrace_profile_lock
);
987 if (ftrace_profile_enabled
^ val
) {
989 ret
= ftrace_profile_init();
995 ret
= register_ftrace_profiler();
1000 ftrace_profile_enabled
= 1;
1002 ftrace_profile_enabled
= 0;
1004 * unregister_ftrace_profiler calls stop_machine
1005 * so this acts like an synchronize_sched.
1007 unregister_ftrace_profiler();
1011 mutex_unlock(&ftrace_profile_lock
);
1019 ftrace_profile_read(struct file
*filp
, char __user
*ubuf
,
1020 size_t cnt
, loff_t
*ppos
)
1022 char buf
[64]; /* big enough to hold a number */
1025 r
= sprintf(buf
, "%u\n", ftrace_profile_enabled
);
1026 return simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, r
);
1029 static const struct file_operations ftrace_profile_fops
= {
1030 .open
= tracing_open_generic
,
1031 .read
= ftrace_profile_read
,
1032 .write
= ftrace_profile_write
,
1033 .llseek
= default_llseek
,
1036 /* used to initialize the real stat files */
1037 static struct tracer_stat function_stats __initdata
= {
1038 .name
= "functions",
1039 .stat_start
= function_stat_start
,
1040 .stat_next
= function_stat_next
,
1041 .stat_cmp
= function_stat_cmp
,
1042 .stat_headers
= function_stat_headers
,
1043 .stat_show
= function_stat_show
1046 static __init
void ftrace_profile_tracefs(struct dentry
*d_tracer
)
1048 struct ftrace_profile_stat
*stat
;
1049 struct dentry
*entry
;
1054 for_each_possible_cpu(cpu
) {
1055 stat
= &per_cpu(ftrace_profile_stats
, cpu
);
1057 name
= kasprintf(GFP_KERNEL
, "function%d", cpu
);
1060 * The files created are permanent, if something happens
1061 * we still do not free memory.
1064 "Could not allocate stat file for cpu %d\n",
1068 stat
->stat
= function_stats
;
1069 stat
->stat
.name
= name
;
1070 ret
= register_stat_tracer(&stat
->stat
);
1073 "Could not register function stat for cpu %d\n",
1080 entry
= tracefs_create_file("function_profile_enabled", 0644,
1081 d_tracer
, NULL
, &ftrace_profile_fops
);
1083 pr_warn("Could not create tracefs 'function_profile_enabled' entry\n");
1086 #else /* CONFIG_FUNCTION_PROFILER */
1087 static __init
void ftrace_profile_tracefs(struct dentry
*d_tracer
)
1090 #endif /* CONFIG_FUNCTION_PROFILER */
1092 static struct pid
* const ftrace_swapper_pid
= &init_struct_pid
;
1094 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1095 static int ftrace_graph_active
;
1097 # define ftrace_graph_active 0
1100 #ifdef CONFIG_DYNAMIC_FTRACE
1102 static struct ftrace_ops
*removed_ops
;
1105 * Set when doing a global update, like enabling all recs or disabling them.
1106 * It is not set when just updating a single ftrace_ops.
1108 static bool update_all_ops
;
1110 #ifndef CONFIG_FTRACE_MCOUNT_RECORD
1111 # error Dynamic ftrace depends on MCOUNT_RECORD
1114 struct ftrace_func_entry
{
1115 struct hlist_node hlist
;
1119 struct ftrace_func_probe
{
1120 struct ftrace_probe_ops
*probe_ops
;
1121 struct ftrace_ops ops
;
1122 struct trace_array
*tr
;
1123 struct list_head list
;
1129 * We make these constant because no one should touch them,
1130 * but they are used as the default "empty hash", to avoid allocating
1131 * it all the time. These are in a read only section such that if
1132 * anyone does try to modify it, it will cause an exception.
1134 static const struct hlist_head empty_buckets
[1];
1135 static const struct ftrace_hash empty_hash
= {
1136 .buckets
= (struct hlist_head
*)empty_buckets
,
1138 #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash)
1140 static struct ftrace_ops global_ops
= {
1141 .func
= ftrace_stub
,
1142 .local_hash
.notrace_hash
= EMPTY_HASH
,
1143 .local_hash
.filter_hash
= EMPTY_HASH
,
1144 INIT_OPS_HASH(global_ops
)
1145 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
|
1146 FTRACE_OPS_FL_INITIALIZED
|
1151 * This is used by __kernel_text_address() to return true if the
1152 * address is on a dynamically allocated trampoline that would
1153 * not return true for either core_kernel_text() or
1154 * is_module_text_address().
1156 bool is_ftrace_trampoline(unsigned long addr
)
1158 struct ftrace_ops
*op
;
1162 * Some of the ops may be dynamically allocated,
1163 * they are freed after a synchronize_sched().
1165 preempt_disable_notrace();
1167 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
1169 * This is to check for dynamically allocated trampolines.
1170 * Trampolines that are in kernel text will have
1171 * core_kernel_text() return true.
1173 if (op
->trampoline
&& op
->trampoline_size
)
1174 if (addr
>= op
->trampoline
&&
1175 addr
< op
->trampoline
+ op
->trampoline_size
) {
1179 } while_for_each_ftrace_op(op
);
1182 preempt_enable_notrace();
1187 struct ftrace_page
{
1188 struct ftrace_page
*next
;
1189 struct dyn_ftrace
*records
;
1194 #define ENTRY_SIZE sizeof(struct dyn_ftrace)
1195 #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE)
1197 /* estimate from running different kernels */
1198 #define NR_TO_INIT 10000
1200 static struct ftrace_page
*ftrace_pages_start
;
1201 static struct ftrace_page
*ftrace_pages
;
1203 static __always_inline
unsigned long
1204 ftrace_hash_key(struct ftrace_hash
*hash
, unsigned long ip
)
1206 if (hash
->size_bits
> 0)
1207 return hash_long(ip
, hash
->size_bits
);
1212 /* Only use this function if ftrace_hash_empty() has already been tested */
1213 static __always_inline
struct ftrace_func_entry
*
1214 __ftrace_lookup_ip(struct ftrace_hash
*hash
, unsigned long ip
)
1217 struct ftrace_func_entry
*entry
;
1218 struct hlist_head
*hhd
;
1220 key
= ftrace_hash_key(hash
, ip
);
1221 hhd
= &hash
->buckets
[key
];
1223 hlist_for_each_entry_rcu_notrace(entry
, hhd
, hlist
) {
1224 if (entry
->ip
== ip
)
1231 * ftrace_lookup_ip - Test to see if an ip exists in an ftrace_hash
1232 * @hash: The hash to look at
1233 * @ip: The instruction pointer to test
1235 * Search a given @hash to see if a given instruction pointer (@ip)
1238 * Returns the entry that holds the @ip if found. NULL otherwise.
1240 struct ftrace_func_entry
*
1241 ftrace_lookup_ip(struct ftrace_hash
*hash
, unsigned long ip
)
1243 if (ftrace_hash_empty(hash
))
1246 return __ftrace_lookup_ip(hash
, ip
);
1249 static void __add_hash_entry(struct ftrace_hash
*hash
,
1250 struct ftrace_func_entry
*entry
)
1252 struct hlist_head
*hhd
;
1255 key
= ftrace_hash_key(hash
, entry
->ip
);
1256 hhd
= &hash
->buckets
[key
];
1257 hlist_add_head(&entry
->hlist
, hhd
);
1261 static int add_hash_entry(struct ftrace_hash
*hash
, unsigned long ip
)
1263 struct ftrace_func_entry
*entry
;
1265 entry
= kmalloc(sizeof(*entry
), GFP_KERNEL
);
1270 __add_hash_entry(hash
, entry
);
1276 free_hash_entry(struct ftrace_hash
*hash
,
1277 struct ftrace_func_entry
*entry
)
1279 hlist_del(&entry
->hlist
);
1285 remove_hash_entry(struct ftrace_hash
*hash
,
1286 struct ftrace_func_entry
*entry
)
1288 hlist_del_rcu(&entry
->hlist
);
1292 static void ftrace_hash_clear(struct ftrace_hash
*hash
)
1294 struct hlist_head
*hhd
;
1295 struct hlist_node
*tn
;
1296 struct ftrace_func_entry
*entry
;
1297 int size
= 1 << hash
->size_bits
;
1303 for (i
= 0; i
< size
; i
++) {
1304 hhd
= &hash
->buckets
[i
];
1305 hlist_for_each_entry_safe(entry
, tn
, hhd
, hlist
)
1306 free_hash_entry(hash
, entry
);
1308 FTRACE_WARN_ON(hash
->count
);
1311 static void free_ftrace_mod(struct ftrace_mod_load
*ftrace_mod
)
1313 list_del(&ftrace_mod
->list
);
1314 kfree(ftrace_mod
->module
);
1315 kfree(ftrace_mod
->func
);
1319 static void clear_ftrace_mod_list(struct list_head
*head
)
1321 struct ftrace_mod_load
*p
, *n
;
1323 /* stack tracer isn't supported yet */
1327 mutex_lock(&ftrace_lock
);
1328 list_for_each_entry_safe(p
, n
, head
, list
)
1330 mutex_unlock(&ftrace_lock
);
1333 static void free_ftrace_hash(struct ftrace_hash
*hash
)
1335 if (!hash
|| hash
== EMPTY_HASH
)
1337 ftrace_hash_clear(hash
);
1338 kfree(hash
->buckets
);
1342 static void __free_ftrace_hash_rcu(struct rcu_head
*rcu
)
1344 struct ftrace_hash
*hash
;
1346 hash
= container_of(rcu
, struct ftrace_hash
, rcu
);
1347 free_ftrace_hash(hash
);
1350 static void free_ftrace_hash_rcu(struct ftrace_hash
*hash
)
1352 if (!hash
|| hash
== EMPTY_HASH
)
1354 call_rcu_sched(&hash
->rcu
, __free_ftrace_hash_rcu
);
1357 void ftrace_free_filter(struct ftrace_ops
*ops
)
1359 ftrace_ops_init(ops
);
1360 free_ftrace_hash(ops
->func_hash
->filter_hash
);
1361 free_ftrace_hash(ops
->func_hash
->notrace_hash
);
1364 static struct ftrace_hash
*alloc_ftrace_hash(int size_bits
)
1366 struct ftrace_hash
*hash
;
1369 hash
= kzalloc(sizeof(*hash
), GFP_KERNEL
);
1373 size
= 1 << size_bits
;
1374 hash
->buckets
= kcalloc(size
, sizeof(*hash
->buckets
), GFP_KERNEL
);
1376 if (!hash
->buckets
) {
1381 hash
->size_bits
= size_bits
;
1387 static int ftrace_add_mod(struct trace_array
*tr
,
1388 const char *func
, const char *module
,
1391 struct ftrace_mod_load
*ftrace_mod
;
1392 struct list_head
*mod_head
= enable
? &tr
->mod_trace
: &tr
->mod_notrace
;
1394 ftrace_mod
= kzalloc(sizeof(*ftrace_mod
), GFP_KERNEL
);
1398 ftrace_mod
->func
= kstrdup(func
, GFP_KERNEL
);
1399 ftrace_mod
->module
= kstrdup(module
, GFP_KERNEL
);
1400 ftrace_mod
->enable
= enable
;
1402 if (!ftrace_mod
->func
|| !ftrace_mod
->module
)
1405 list_add(&ftrace_mod
->list
, mod_head
);
1410 free_ftrace_mod(ftrace_mod
);
1415 static struct ftrace_hash
*
1416 alloc_and_copy_ftrace_hash(int size_bits
, struct ftrace_hash
*hash
)
1418 struct ftrace_func_entry
*entry
;
1419 struct ftrace_hash
*new_hash
;
1424 new_hash
= alloc_ftrace_hash(size_bits
);
1429 new_hash
->flags
= hash
->flags
;
1432 if (ftrace_hash_empty(hash
))
1435 size
= 1 << hash
->size_bits
;
1436 for (i
= 0; i
< size
; i
++) {
1437 hlist_for_each_entry(entry
, &hash
->buckets
[i
], hlist
) {
1438 ret
= add_hash_entry(new_hash
, entry
->ip
);
1444 FTRACE_WARN_ON(new_hash
->count
!= hash
->count
);
1449 free_ftrace_hash(new_hash
);
1454 ftrace_hash_rec_disable_modify(struct ftrace_ops
*ops
, int filter_hash
);
1456 ftrace_hash_rec_enable_modify(struct ftrace_ops
*ops
, int filter_hash
);
1458 static int ftrace_hash_ipmodify_update(struct ftrace_ops
*ops
,
1459 struct ftrace_hash
*new_hash
);
1461 static struct ftrace_hash
*
1462 __ftrace_hash_move(struct ftrace_hash
*src
)
1464 struct ftrace_func_entry
*entry
;
1465 struct hlist_node
*tn
;
1466 struct hlist_head
*hhd
;
1467 struct ftrace_hash
*new_hash
;
1468 int size
= src
->count
;
1473 * If the new source is empty, just return the empty_hash.
1475 if (ftrace_hash_empty(src
))
1479 * Make the hash size about 1/2 the # found
1481 for (size
/= 2; size
; size
>>= 1)
1484 /* Don't allocate too much */
1485 if (bits
> FTRACE_HASH_MAX_BITS
)
1486 bits
= FTRACE_HASH_MAX_BITS
;
1488 new_hash
= alloc_ftrace_hash(bits
);
1492 new_hash
->flags
= src
->flags
;
1494 size
= 1 << src
->size_bits
;
1495 for (i
= 0; i
< size
; i
++) {
1496 hhd
= &src
->buckets
[i
];
1497 hlist_for_each_entry_safe(entry
, tn
, hhd
, hlist
) {
1498 remove_hash_entry(src
, entry
);
1499 __add_hash_entry(new_hash
, entry
);
1507 ftrace_hash_move(struct ftrace_ops
*ops
, int enable
,
1508 struct ftrace_hash
**dst
, struct ftrace_hash
*src
)
1510 struct ftrace_hash
*new_hash
;
1513 /* Reject setting notrace hash on IPMODIFY ftrace_ops */
1514 if (ops
->flags
& FTRACE_OPS_FL_IPMODIFY
&& !enable
)
1517 new_hash
= __ftrace_hash_move(src
);
1521 /* Make sure this can be applied if it is IPMODIFY ftrace_ops */
1523 /* IPMODIFY should be updated only when filter_hash updating */
1524 ret
= ftrace_hash_ipmodify_update(ops
, new_hash
);
1526 free_ftrace_hash(new_hash
);
1532 * Remove the current set, update the hash and add
1535 ftrace_hash_rec_disable_modify(ops
, enable
);
1537 rcu_assign_pointer(*dst
, new_hash
);
1539 ftrace_hash_rec_enable_modify(ops
, enable
);
1544 static bool hash_contains_ip(unsigned long ip
,
1545 struct ftrace_ops_hash
*hash
)
1548 * The function record is a match if it exists in the filter
1549 * hash and not in the notrace hash. Note, an emty hash is
1550 * considered a match for the filter hash, but an empty
1551 * notrace hash is considered not in the notrace hash.
1553 return (ftrace_hash_empty(hash
->filter_hash
) ||
1554 __ftrace_lookup_ip(hash
->filter_hash
, ip
)) &&
1555 (ftrace_hash_empty(hash
->notrace_hash
) ||
1556 !__ftrace_lookup_ip(hash
->notrace_hash
, ip
));
1560 * Test the hashes for this ops to see if we want to call
1561 * the ops->func or not.
1563 * It's a match if the ip is in the ops->filter_hash or
1564 * the filter_hash does not exist or is empty,
1566 * the ip is not in the ops->notrace_hash.
1568 * This needs to be called with preemption disabled as
1569 * the hashes are freed with call_rcu_sched().
1572 ftrace_ops_test(struct ftrace_ops
*ops
, unsigned long ip
, void *regs
)
1574 struct ftrace_ops_hash hash
;
1577 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
1579 * There's a small race when adding ops that the ftrace handler
1580 * that wants regs, may be called without them. We can not
1581 * allow that handler to be called if regs is NULL.
1583 if (regs
== NULL
&& (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
))
1587 rcu_assign_pointer(hash
.filter_hash
, ops
->func_hash
->filter_hash
);
1588 rcu_assign_pointer(hash
.notrace_hash
, ops
->func_hash
->notrace_hash
);
1590 if (hash_contains_ip(ip
, &hash
))
1599 * This is a double for. Do not use 'break' to break out of the loop,
1600 * you must use a goto.
1602 #define do_for_each_ftrace_rec(pg, rec) \
1603 for (pg = ftrace_pages_start; pg; pg = pg->next) { \
1605 for (_____i = 0; _____i < pg->index; _____i++) { \
1606 rec = &pg->records[_____i];
1608 #define while_for_each_ftrace_rec() \
1613 static int ftrace_cmp_recs(const void *a
, const void *b
)
1615 const struct dyn_ftrace
*key
= a
;
1616 const struct dyn_ftrace
*rec
= b
;
1618 if (key
->flags
< rec
->ip
)
1620 if (key
->ip
>= rec
->ip
+ MCOUNT_INSN_SIZE
)
1626 * ftrace_location_range - return the first address of a traced location
1627 * if it touches the given ip range
1628 * @start: start of range to search.
1629 * @end: end of range to search (inclusive). @end points to the last byte
1632 * Returns rec->ip if the related ftrace location is a least partly within
1633 * the given address range. That is, the first address of the instruction
1634 * that is either a NOP or call to the function tracer. It checks the ftrace
1635 * internal tables to determine if the address belongs or not.
1637 unsigned long ftrace_location_range(unsigned long start
, unsigned long end
)
1639 struct ftrace_page
*pg
;
1640 struct dyn_ftrace
*rec
;
1641 struct dyn_ftrace key
;
1644 key
.flags
= end
; /* overload flags, as it is unsigned long */
1646 for (pg
= ftrace_pages_start
; pg
; pg
= pg
->next
) {
1647 if (end
< pg
->records
[0].ip
||
1648 start
>= (pg
->records
[pg
->index
- 1].ip
+ MCOUNT_INSN_SIZE
))
1650 rec
= bsearch(&key
, pg
->records
, pg
->index
,
1651 sizeof(struct dyn_ftrace
),
1661 * ftrace_location - return true if the ip giving is a traced location
1662 * @ip: the instruction pointer to check
1664 * Returns rec->ip if @ip given is a pointer to a ftrace location.
1665 * That is, the instruction that is either a NOP or call to
1666 * the function tracer. It checks the ftrace internal tables to
1667 * determine if the address belongs or not.
1669 unsigned long ftrace_location(unsigned long ip
)
1671 return ftrace_location_range(ip
, ip
);
1675 * ftrace_text_reserved - return true if range contains an ftrace location
1676 * @start: start of range to search
1677 * @end: end of range to search (inclusive). @end points to the last byte to check.
1679 * Returns 1 if @start and @end contains a ftrace location.
1680 * That is, the instruction that is either a NOP or call to
1681 * the function tracer. It checks the ftrace internal tables to
1682 * determine if the address belongs or not.
1684 int ftrace_text_reserved(const void *start
, const void *end
)
1688 ret
= ftrace_location_range((unsigned long)start
,
1689 (unsigned long)end
);
1694 /* Test if ops registered to this rec needs regs */
1695 static bool test_rec_ops_needs_regs(struct dyn_ftrace
*rec
)
1697 struct ftrace_ops
*ops
;
1698 bool keep_regs
= false;
1700 for (ops
= ftrace_ops_list
;
1701 ops
!= &ftrace_list_end
; ops
= ops
->next
) {
1702 /* pass rec in as regs to have non-NULL val */
1703 if (ftrace_ops_test(ops
, rec
->ip
, rec
)) {
1704 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
) {
1714 static bool __ftrace_hash_rec_update(struct ftrace_ops
*ops
,
1718 struct ftrace_hash
*hash
;
1719 struct ftrace_hash
*other_hash
;
1720 struct ftrace_page
*pg
;
1721 struct dyn_ftrace
*rec
;
1722 bool update
= false;
1726 /* Only update if the ops has been registered */
1727 if (!(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
1731 * In the filter_hash case:
1732 * If the count is zero, we update all records.
1733 * Otherwise we just update the items in the hash.
1735 * In the notrace_hash case:
1736 * We enable the update in the hash.
1737 * As disabling notrace means enabling the tracing,
1738 * and enabling notrace means disabling, the inc variable
1742 hash
= ops
->func_hash
->filter_hash
;
1743 other_hash
= ops
->func_hash
->notrace_hash
;
1744 if (ftrace_hash_empty(hash
))
1748 hash
= ops
->func_hash
->notrace_hash
;
1749 other_hash
= ops
->func_hash
->filter_hash
;
1751 * If the notrace hash has no items,
1752 * then there's nothing to do.
1754 if (ftrace_hash_empty(hash
))
1758 do_for_each_ftrace_rec(pg
, rec
) {
1759 int in_other_hash
= 0;
1763 if (rec
->flags
& FTRACE_FL_DISABLED
)
1768 * Only the filter_hash affects all records.
1769 * Update if the record is not in the notrace hash.
1771 if (!other_hash
|| !ftrace_lookup_ip(other_hash
, rec
->ip
))
1774 in_hash
= !!ftrace_lookup_ip(hash
, rec
->ip
);
1775 in_other_hash
= !!ftrace_lookup_ip(other_hash
, rec
->ip
);
1778 * If filter_hash is set, we want to match all functions
1779 * that are in the hash but not in the other hash.
1781 * If filter_hash is not set, then we are decrementing.
1782 * That means we match anything that is in the hash
1783 * and also in the other_hash. That is, we need to turn
1784 * off functions in the other hash because they are disabled
1787 if (filter_hash
&& in_hash
&& !in_other_hash
)
1789 else if (!filter_hash
&& in_hash
&&
1790 (in_other_hash
|| ftrace_hash_empty(other_hash
)))
1798 if (FTRACE_WARN_ON(ftrace_rec_count(rec
) == FTRACE_REF_MAX
))
1802 * If there's only a single callback registered to a
1803 * function, and the ops has a trampoline registered
1804 * for it, then we can call it directly.
1806 if (ftrace_rec_count(rec
) == 1 && ops
->trampoline
)
1807 rec
->flags
|= FTRACE_FL_TRAMP
;
1810 * If we are adding another function callback
1811 * to this function, and the previous had a
1812 * custom trampoline in use, then we need to go
1813 * back to the default trampoline.
1815 rec
->flags
&= ~FTRACE_FL_TRAMP
;
1818 * If any ops wants regs saved for this function
1819 * then all ops will get saved regs.
1821 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
)
1822 rec
->flags
|= FTRACE_FL_REGS
;
1824 if (FTRACE_WARN_ON(ftrace_rec_count(rec
) == 0))
1829 * If the rec had REGS enabled and the ops that is
1830 * being removed had REGS set, then see if there is
1831 * still any ops for this record that wants regs.
1832 * If not, we can stop recording them.
1834 if (ftrace_rec_count(rec
) > 0 &&
1835 rec
->flags
& FTRACE_FL_REGS
&&
1836 ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
) {
1837 if (!test_rec_ops_needs_regs(rec
))
1838 rec
->flags
&= ~FTRACE_FL_REGS
;
1842 * If the rec had TRAMP enabled, then it needs to
1843 * be cleared. As TRAMP can only be enabled iff
1844 * there is only a single ops attached to it.
1845 * In otherwords, always disable it on decrementing.
1846 * In the future, we may set it if rec count is
1847 * decremented to one, and the ops that is left
1850 rec
->flags
&= ~FTRACE_FL_TRAMP
;
1853 * flags will be cleared in ftrace_check_record()
1854 * if rec count is zero.
1859 /* Must match FTRACE_UPDATE_CALLS in ftrace_modify_all_code() */
1860 update
|= ftrace_test_record(rec
, 1) != FTRACE_UPDATE_IGNORE
;
1862 /* Shortcut, if we handled all records, we are done. */
1863 if (!all
&& count
== hash
->count
)
1865 } while_for_each_ftrace_rec();
1870 static bool ftrace_hash_rec_disable(struct ftrace_ops
*ops
,
1873 return __ftrace_hash_rec_update(ops
, filter_hash
, 0);
1876 static bool ftrace_hash_rec_enable(struct ftrace_ops
*ops
,
1879 return __ftrace_hash_rec_update(ops
, filter_hash
, 1);
1882 static void ftrace_hash_rec_update_modify(struct ftrace_ops
*ops
,
1883 int filter_hash
, int inc
)
1885 struct ftrace_ops
*op
;
1887 __ftrace_hash_rec_update(ops
, filter_hash
, inc
);
1889 if (ops
->func_hash
!= &global_ops
.local_hash
)
1893 * If the ops shares the global_ops hash, then we need to update
1894 * all ops that are enabled and use this hash.
1896 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
1900 if (op
->func_hash
== &global_ops
.local_hash
)
1901 __ftrace_hash_rec_update(op
, filter_hash
, inc
);
1902 } while_for_each_ftrace_op(op
);
1905 static void ftrace_hash_rec_disable_modify(struct ftrace_ops
*ops
,
1908 ftrace_hash_rec_update_modify(ops
, filter_hash
, 0);
1911 static void ftrace_hash_rec_enable_modify(struct ftrace_ops
*ops
,
1914 ftrace_hash_rec_update_modify(ops
, filter_hash
, 1);
1918 * Try to update IPMODIFY flag on each ftrace_rec. Return 0 if it is OK
1919 * or no-needed to update, -EBUSY if it detects a conflict of the flag
1920 * on a ftrace_rec, and -EINVAL if the new_hash tries to trace all recs.
1921 * Note that old_hash and new_hash has below meanings
1922 * - If the hash is NULL, it hits all recs (if IPMODIFY is set, this is rejected)
1923 * - If the hash is EMPTY_HASH, it hits nothing
1924 * - Anything else hits the recs which match the hash entries.
1926 static int __ftrace_hash_update_ipmodify(struct ftrace_ops
*ops
,
1927 struct ftrace_hash
*old_hash
,
1928 struct ftrace_hash
*new_hash
)
1930 struct ftrace_page
*pg
;
1931 struct dyn_ftrace
*rec
, *end
= NULL
;
1934 /* Only update if the ops has been registered */
1935 if (!(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
1938 if (!(ops
->flags
& FTRACE_OPS_FL_IPMODIFY
))
1942 * Since the IPMODIFY is a very address sensitive action, we do not
1943 * allow ftrace_ops to set all functions to new hash.
1945 if (!new_hash
|| !old_hash
)
1948 /* Update rec->flags */
1949 do_for_each_ftrace_rec(pg
, rec
) {
1951 if (rec
->flags
& FTRACE_FL_DISABLED
)
1954 /* We need to update only differences of filter_hash */
1955 in_old
= !!ftrace_lookup_ip(old_hash
, rec
->ip
);
1956 in_new
= !!ftrace_lookup_ip(new_hash
, rec
->ip
);
1957 if (in_old
== in_new
)
1961 /* New entries must ensure no others are using it */
1962 if (rec
->flags
& FTRACE_FL_IPMODIFY
)
1964 rec
->flags
|= FTRACE_FL_IPMODIFY
;
1965 } else /* Removed entry */
1966 rec
->flags
&= ~FTRACE_FL_IPMODIFY
;
1967 } while_for_each_ftrace_rec();
1974 /* Roll back what we did above */
1975 do_for_each_ftrace_rec(pg
, rec
) {
1977 if (rec
->flags
& FTRACE_FL_DISABLED
)
1983 in_old
= !!ftrace_lookup_ip(old_hash
, rec
->ip
);
1984 in_new
= !!ftrace_lookup_ip(new_hash
, rec
->ip
);
1985 if (in_old
== in_new
)
1989 rec
->flags
&= ~FTRACE_FL_IPMODIFY
;
1991 rec
->flags
|= FTRACE_FL_IPMODIFY
;
1992 } while_for_each_ftrace_rec();
1998 static int ftrace_hash_ipmodify_enable(struct ftrace_ops
*ops
)
2000 struct ftrace_hash
*hash
= ops
->func_hash
->filter_hash
;
2002 if (ftrace_hash_empty(hash
))
2005 return __ftrace_hash_update_ipmodify(ops
, EMPTY_HASH
, hash
);
2008 /* Disabling always succeeds */
2009 static void ftrace_hash_ipmodify_disable(struct ftrace_ops
*ops
)
2011 struct ftrace_hash
*hash
= ops
->func_hash
->filter_hash
;
2013 if (ftrace_hash_empty(hash
))
2016 __ftrace_hash_update_ipmodify(ops
, hash
, EMPTY_HASH
);
2019 static int ftrace_hash_ipmodify_update(struct ftrace_ops
*ops
,
2020 struct ftrace_hash
*new_hash
)
2022 struct ftrace_hash
*old_hash
= ops
->func_hash
->filter_hash
;
2024 if (ftrace_hash_empty(old_hash
))
2027 if (ftrace_hash_empty(new_hash
))
2030 return __ftrace_hash_update_ipmodify(ops
, old_hash
, new_hash
);
2033 static void print_ip_ins(const char *fmt
, const unsigned char *p
)
2037 printk(KERN_CONT
"%s", fmt
);
2039 for (i
= 0; i
< MCOUNT_INSN_SIZE
; i
++)
2040 printk(KERN_CONT
"%s%02x", i
? ":" : "", p
[i
]);
2043 static struct ftrace_ops
*
2044 ftrace_find_tramp_ops_any(struct dyn_ftrace
*rec
);
2045 static struct ftrace_ops
*
2046 ftrace_find_tramp_ops_next(struct dyn_ftrace
*rec
, struct ftrace_ops
*ops
);
2048 enum ftrace_bug_type ftrace_bug_type
;
2049 const void *ftrace_expected
;
2051 static void print_bug_type(void)
2053 switch (ftrace_bug_type
) {
2054 case FTRACE_BUG_UNKNOWN
:
2056 case FTRACE_BUG_INIT
:
2057 pr_info("Initializing ftrace call sites\n");
2059 case FTRACE_BUG_NOP
:
2060 pr_info("Setting ftrace call site to NOP\n");
2062 case FTRACE_BUG_CALL
:
2063 pr_info("Setting ftrace call site to call ftrace function\n");
2065 case FTRACE_BUG_UPDATE
:
2066 pr_info("Updating ftrace call site to call a different ftrace function\n");
2072 * ftrace_bug - report and shutdown function tracer
2073 * @failed: The failed type (EFAULT, EINVAL, EPERM)
2074 * @rec: The record that failed
2076 * The arch code that enables or disables the function tracing
2077 * can call ftrace_bug() when it has detected a problem in
2078 * modifying the code. @failed should be one of either:
2079 * EFAULT - if the problem happens on reading the @ip address
2080 * EINVAL - if what is read at @ip is not what was expected
2081 * EPERM - if the problem happens on writting to the @ip address
2083 void ftrace_bug(int failed
, struct dyn_ftrace
*rec
)
2085 unsigned long ip
= rec
? rec
->ip
: 0;
2089 FTRACE_WARN_ON_ONCE(1);
2090 pr_info("ftrace faulted on modifying ");
2094 FTRACE_WARN_ON_ONCE(1);
2095 pr_info("ftrace failed to modify ");
2097 print_ip_ins(" actual: ", (unsigned char *)ip
);
2099 if (ftrace_expected
) {
2100 print_ip_ins(" expected: ", ftrace_expected
);
2105 FTRACE_WARN_ON_ONCE(1);
2106 pr_info("ftrace faulted on writing ");
2110 FTRACE_WARN_ON_ONCE(1);
2111 pr_info("ftrace faulted on unknown error ");
2116 struct ftrace_ops
*ops
= NULL
;
2118 pr_info("ftrace record flags: %lx\n", rec
->flags
);
2119 pr_cont(" (%ld)%s", ftrace_rec_count(rec
),
2120 rec
->flags
& FTRACE_FL_REGS
? " R" : " ");
2121 if (rec
->flags
& FTRACE_FL_TRAMP_EN
) {
2122 ops
= ftrace_find_tramp_ops_any(rec
);
2125 pr_cont("\ttramp: %pS (%pS)",
2126 (void *)ops
->trampoline
,
2128 ops
= ftrace_find_tramp_ops_next(rec
, ops
);
2131 pr_cont("\ttramp: ERROR!");
2134 ip
= ftrace_get_addr_curr(rec
);
2135 pr_cont("\n expected tramp: %lx\n", ip
);
2139 static int ftrace_check_record(struct dyn_ftrace
*rec
, int enable
, int update
)
2141 unsigned long flag
= 0UL;
2143 ftrace_bug_type
= FTRACE_BUG_UNKNOWN
;
2145 if (rec
->flags
& FTRACE_FL_DISABLED
)
2146 return FTRACE_UPDATE_IGNORE
;
2149 * If we are updating calls:
2151 * If the record has a ref count, then we need to enable it
2152 * because someone is using it.
2154 * Otherwise we make sure its disabled.
2156 * If we are disabling calls, then disable all records that
2159 if (enable
&& ftrace_rec_count(rec
))
2160 flag
= FTRACE_FL_ENABLED
;
2163 * If enabling and the REGS flag does not match the REGS_EN, or
2164 * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore
2165 * this record. Set flags to fail the compare against ENABLED.
2168 if (!(rec
->flags
& FTRACE_FL_REGS
) !=
2169 !(rec
->flags
& FTRACE_FL_REGS_EN
))
2170 flag
|= FTRACE_FL_REGS
;
2172 if (!(rec
->flags
& FTRACE_FL_TRAMP
) !=
2173 !(rec
->flags
& FTRACE_FL_TRAMP_EN
))
2174 flag
|= FTRACE_FL_TRAMP
;
2177 /* If the state of this record hasn't changed, then do nothing */
2178 if ((rec
->flags
& FTRACE_FL_ENABLED
) == flag
)
2179 return FTRACE_UPDATE_IGNORE
;
2182 /* Save off if rec is being enabled (for return value) */
2183 flag
^= rec
->flags
& FTRACE_FL_ENABLED
;
2186 rec
->flags
|= FTRACE_FL_ENABLED
;
2187 if (flag
& FTRACE_FL_REGS
) {
2188 if (rec
->flags
& FTRACE_FL_REGS
)
2189 rec
->flags
|= FTRACE_FL_REGS_EN
;
2191 rec
->flags
&= ~FTRACE_FL_REGS_EN
;
2193 if (flag
& FTRACE_FL_TRAMP
) {
2194 if (rec
->flags
& FTRACE_FL_TRAMP
)
2195 rec
->flags
|= FTRACE_FL_TRAMP_EN
;
2197 rec
->flags
&= ~FTRACE_FL_TRAMP_EN
;
2202 * If this record is being updated from a nop, then
2203 * return UPDATE_MAKE_CALL.
2205 * return UPDATE_MODIFY_CALL to tell the caller to convert
2206 * from the save regs, to a non-save regs function or
2207 * vice versa, or from a trampoline call.
2209 if (flag
& FTRACE_FL_ENABLED
) {
2210 ftrace_bug_type
= FTRACE_BUG_CALL
;
2211 return FTRACE_UPDATE_MAKE_CALL
;
2214 ftrace_bug_type
= FTRACE_BUG_UPDATE
;
2215 return FTRACE_UPDATE_MODIFY_CALL
;
2219 /* If there's no more users, clear all flags */
2220 if (!ftrace_rec_count(rec
))
2224 * Just disable the record, but keep the ops TRAMP
2225 * and REGS states. The _EN flags must be disabled though.
2227 rec
->flags
&= ~(FTRACE_FL_ENABLED
| FTRACE_FL_TRAMP_EN
|
2231 ftrace_bug_type
= FTRACE_BUG_NOP
;
2232 return FTRACE_UPDATE_MAKE_NOP
;
2236 * ftrace_update_record, set a record that now is tracing or not
2237 * @rec: the record to update
2238 * @enable: set to 1 if the record is tracing, zero to force disable
2240 * The records that represent all functions that can be traced need
2241 * to be updated when tracing has been enabled.
2243 int ftrace_update_record(struct dyn_ftrace
*rec
, int enable
)
2245 return ftrace_check_record(rec
, enable
, 1);
2249 * ftrace_test_record, check if the record has been enabled or not
2250 * @rec: the record to test
2251 * @enable: set to 1 to check if enabled, 0 if it is disabled
2253 * The arch code may need to test if a record is already set to
2254 * tracing to determine how to modify the function code that it
2257 int ftrace_test_record(struct dyn_ftrace
*rec
, int enable
)
2259 return ftrace_check_record(rec
, enable
, 0);
2262 static struct ftrace_ops
*
2263 ftrace_find_tramp_ops_any(struct dyn_ftrace
*rec
)
2265 struct ftrace_ops
*op
;
2266 unsigned long ip
= rec
->ip
;
2268 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
2270 if (!op
->trampoline
)
2273 if (hash_contains_ip(ip
, op
->func_hash
))
2275 } while_for_each_ftrace_op(op
);
2280 static struct ftrace_ops
*
2281 ftrace_find_tramp_ops_next(struct dyn_ftrace
*rec
,
2282 struct ftrace_ops
*op
)
2284 unsigned long ip
= rec
->ip
;
2286 while_for_each_ftrace_op(op
) {
2288 if (!op
->trampoline
)
2291 if (hash_contains_ip(ip
, op
->func_hash
))
2298 static struct ftrace_ops
*
2299 ftrace_find_tramp_ops_curr(struct dyn_ftrace
*rec
)
2301 struct ftrace_ops
*op
;
2302 unsigned long ip
= rec
->ip
;
2305 * Need to check removed ops first.
2306 * If they are being removed, and this rec has a tramp,
2307 * and this rec is in the ops list, then it would be the
2308 * one with the tramp.
2311 if (hash_contains_ip(ip
, &removed_ops
->old_hash
))
2316 * Need to find the current trampoline for a rec.
2317 * Now, a trampoline is only attached to a rec if there
2318 * was a single 'ops' attached to it. But this can be called
2319 * when we are adding another op to the rec or removing the
2320 * current one. Thus, if the op is being added, we can
2321 * ignore it because it hasn't attached itself to the rec
2324 * If an ops is being modified (hooking to different functions)
2325 * then we don't care about the new functions that are being
2326 * added, just the old ones (that are probably being removed).
2328 * If we are adding an ops to a function that already is using
2329 * a trampoline, it needs to be removed (trampolines are only
2330 * for single ops connected), then an ops that is not being
2331 * modified also needs to be checked.
2333 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
2335 if (!op
->trampoline
)
2339 * If the ops is being added, it hasn't gotten to
2340 * the point to be removed from this tree yet.
2342 if (op
->flags
& FTRACE_OPS_FL_ADDING
)
2347 * If the ops is being modified and is in the old
2348 * hash, then it is probably being removed from this
2351 if ((op
->flags
& FTRACE_OPS_FL_MODIFYING
) &&
2352 hash_contains_ip(ip
, &op
->old_hash
))
2355 * If the ops is not being added or modified, and it's
2356 * in its normal filter hash, then this must be the one
2359 if (!(op
->flags
& FTRACE_OPS_FL_MODIFYING
) &&
2360 hash_contains_ip(ip
, op
->func_hash
))
2363 } while_for_each_ftrace_op(op
);
2368 static struct ftrace_ops
*
2369 ftrace_find_tramp_ops_new(struct dyn_ftrace
*rec
)
2371 struct ftrace_ops
*op
;
2372 unsigned long ip
= rec
->ip
;
2374 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
2375 /* pass rec in as regs to have non-NULL val */
2376 if (hash_contains_ip(ip
, op
->func_hash
))
2378 } while_for_each_ftrace_op(op
);
2384 * ftrace_get_addr_new - Get the call address to set to
2385 * @rec: The ftrace record descriptor
2387 * If the record has the FTRACE_FL_REGS set, that means that it
2388 * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS
2389 * is not not set, then it wants to convert to the normal callback.
2391 * Returns the address of the trampoline to set to
2393 unsigned long ftrace_get_addr_new(struct dyn_ftrace
*rec
)
2395 struct ftrace_ops
*ops
;
2397 /* Trampolines take precedence over regs */
2398 if (rec
->flags
& FTRACE_FL_TRAMP
) {
2399 ops
= ftrace_find_tramp_ops_new(rec
);
2400 if (FTRACE_WARN_ON(!ops
|| !ops
->trampoline
)) {
2401 pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n",
2402 (void *)rec
->ip
, (void *)rec
->ip
, rec
->flags
);
2403 /* Ftrace is shutting down, return anything */
2404 return (unsigned long)FTRACE_ADDR
;
2406 return ops
->trampoline
;
2409 if (rec
->flags
& FTRACE_FL_REGS
)
2410 return (unsigned long)FTRACE_REGS_ADDR
;
2412 return (unsigned long)FTRACE_ADDR
;
2416 * ftrace_get_addr_curr - Get the call address that is already there
2417 * @rec: The ftrace record descriptor
2419 * The FTRACE_FL_REGS_EN is set when the record already points to
2420 * a function that saves all the regs. Basically the '_EN' version
2421 * represents the current state of the function.
2423 * Returns the address of the trampoline that is currently being called
2425 unsigned long ftrace_get_addr_curr(struct dyn_ftrace
*rec
)
2427 struct ftrace_ops
*ops
;
2429 /* Trampolines take precedence over regs */
2430 if (rec
->flags
& FTRACE_FL_TRAMP_EN
) {
2431 ops
= ftrace_find_tramp_ops_curr(rec
);
2432 if (FTRACE_WARN_ON(!ops
)) {
2433 pr_warn("Bad trampoline accounting at: %p (%pS)\n",
2434 (void *)rec
->ip
, (void *)rec
->ip
);
2435 /* Ftrace is shutting down, return anything */
2436 return (unsigned long)FTRACE_ADDR
;
2438 return ops
->trampoline
;
2441 if (rec
->flags
& FTRACE_FL_REGS_EN
)
2442 return (unsigned long)FTRACE_REGS_ADDR
;
2444 return (unsigned long)FTRACE_ADDR
;
2448 __ftrace_replace_code(struct dyn_ftrace
*rec
, int enable
)
2450 unsigned long ftrace_old_addr
;
2451 unsigned long ftrace_addr
;
2454 ftrace_addr
= ftrace_get_addr_new(rec
);
2456 /* This needs to be done before we call ftrace_update_record */
2457 ftrace_old_addr
= ftrace_get_addr_curr(rec
);
2459 ret
= ftrace_update_record(rec
, enable
);
2461 ftrace_bug_type
= FTRACE_BUG_UNKNOWN
;
2464 case FTRACE_UPDATE_IGNORE
:
2467 case FTRACE_UPDATE_MAKE_CALL
:
2468 ftrace_bug_type
= FTRACE_BUG_CALL
;
2469 return ftrace_make_call(rec
, ftrace_addr
);
2471 case FTRACE_UPDATE_MAKE_NOP
:
2472 ftrace_bug_type
= FTRACE_BUG_NOP
;
2473 return ftrace_make_nop(NULL
, rec
, ftrace_old_addr
);
2475 case FTRACE_UPDATE_MODIFY_CALL
:
2476 ftrace_bug_type
= FTRACE_BUG_UPDATE
;
2477 return ftrace_modify_call(rec
, ftrace_old_addr
, ftrace_addr
);
2480 return -1; /* unknow ftrace bug */
2483 void __weak
ftrace_replace_code(int enable
)
2485 struct dyn_ftrace
*rec
;
2486 struct ftrace_page
*pg
;
2489 if (unlikely(ftrace_disabled
))
2492 do_for_each_ftrace_rec(pg
, rec
) {
2494 if (rec
->flags
& FTRACE_FL_DISABLED
)
2497 failed
= __ftrace_replace_code(rec
, enable
);
2499 ftrace_bug(failed
, rec
);
2500 /* Stop processing */
2503 } while_for_each_ftrace_rec();
2506 struct ftrace_rec_iter
{
2507 struct ftrace_page
*pg
;
2512 * ftrace_rec_iter_start, start up iterating over traced functions
2514 * Returns an iterator handle that is used to iterate over all
2515 * the records that represent address locations where functions
2518 * May return NULL if no records are available.
2520 struct ftrace_rec_iter
*ftrace_rec_iter_start(void)
2523 * We only use a single iterator.
2524 * Protected by the ftrace_lock mutex.
2526 static struct ftrace_rec_iter ftrace_rec_iter
;
2527 struct ftrace_rec_iter
*iter
= &ftrace_rec_iter
;
2529 iter
->pg
= ftrace_pages_start
;
2532 /* Could have empty pages */
2533 while (iter
->pg
&& !iter
->pg
->index
)
2534 iter
->pg
= iter
->pg
->next
;
2543 * ftrace_rec_iter_next, get the next record to process.
2544 * @iter: The handle to the iterator.
2546 * Returns the next iterator after the given iterator @iter.
2548 struct ftrace_rec_iter
*ftrace_rec_iter_next(struct ftrace_rec_iter
*iter
)
2552 if (iter
->index
>= iter
->pg
->index
) {
2553 iter
->pg
= iter
->pg
->next
;
2556 /* Could have empty pages */
2557 while (iter
->pg
&& !iter
->pg
->index
)
2558 iter
->pg
= iter
->pg
->next
;
2568 * ftrace_rec_iter_record, get the record at the iterator location
2569 * @iter: The current iterator location
2571 * Returns the record that the current @iter is at.
2573 struct dyn_ftrace
*ftrace_rec_iter_record(struct ftrace_rec_iter
*iter
)
2575 return &iter
->pg
->records
[iter
->index
];
2579 ftrace_code_disable(struct module
*mod
, struct dyn_ftrace
*rec
)
2583 if (unlikely(ftrace_disabled
))
2586 ret
= ftrace_make_nop(mod
, rec
, MCOUNT_ADDR
);
2588 ftrace_bug_type
= FTRACE_BUG_INIT
;
2589 ftrace_bug(ret
, rec
);
2596 * archs can override this function if they must do something
2597 * before the modifying code is performed.
2599 int __weak
ftrace_arch_code_modify_prepare(void)
2605 * archs can override this function if they must do something
2606 * after the modifying code is performed.
2608 int __weak
ftrace_arch_code_modify_post_process(void)
2613 void ftrace_modify_all_code(int command
)
2615 int update
= command
& FTRACE_UPDATE_TRACE_FUNC
;
2619 * If the ftrace_caller calls a ftrace_ops func directly,
2620 * we need to make sure that it only traces functions it
2621 * expects to trace. When doing the switch of functions,
2622 * we need to update to the ftrace_ops_list_func first
2623 * before the transition between old and new calls are set,
2624 * as the ftrace_ops_list_func will check the ops hashes
2625 * to make sure the ops are having the right functions
2629 err
= ftrace_update_ftrace_func(ftrace_ops_list_func
);
2630 if (FTRACE_WARN_ON(err
))
2634 if (command
& FTRACE_UPDATE_CALLS
)
2635 ftrace_replace_code(1);
2636 else if (command
& FTRACE_DISABLE_CALLS
)
2637 ftrace_replace_code(0);
2639 if (update
&& ftrace_trace_function
!= ftrace_ops_list_func
) {
2640 function_trace_op
= set_function_trace_op
;
2642 /* If irqs are disabled, we are in stop machine */
2643 if (!irqs_disabled())
2644 smp_call_function(ftrace_sync_ipi
, NULL
, 1);
2645 err
= ftrace_update_ftrace_func(ftrace_trace_function
);
2646 if (FTRACE_WARN_ON(err
))
2650 if (command
& FTRACE_START_FUNC_RET
)
2651 err
= ftrace_enable_ftrace_graph_caller();
2652 else if (command
& FTRACE_STOP_FUNC_RET
)
2653 err
= ftrace_disable_ftrace_graph_caller();
2654 FTRACE_WARN_ON(err
);
2657 static int __ftrace_modify_code(void *data
)
2659 int *command
= data
;
2661 ftrace_modify_all_code(*command
);
2667 * ftrace_run_stop_machine, go back to the stop machine method
2668 * @command: The command to tell ftrace what to do
2670 * If an arch needs to fall back to the stop machine method, the
2671 * it can call this function.
2673 void ftrace_run_stop_machine(int command
)
2675 stop_machine(__ftrace_modify_code
, &command
, NULL
);
2679 * arch_ftrace_update_code, modify the code to trace or not trace
2680 * @command: The command that needs to be done
2682 * Archs can override this function if it does not need to
2683 * run stop_machine() to modify code.
2685 void __weak
arch_ftrace_update_code(int command
)
2687 ftrace_run_stop_machine(command
);
2690 static void ftrace_run_update_code(int command
)
2694 ret
= ftrace_arch_code_modify_prepare();
2695 FTRACE_WARN_ON(ret
);
2700 * By default we use stop_machine() to modify the code.
2701 * But archs can do what ever they want as long as it
2702 * is safe. The stop_machine() is the safest, but also
2703 * produces the most overhead.
2705 arch_ftrace_update_code(command
);
2707 ret
= ftrace_arch_code_modify_post_process();
2708 FTRACE_WARN_ON(ret
);
2711 static void ftrace_run_modify_code(struct ftrace_ops
*ops
, int command
,
2712 struct ftrace_ops_hash
*old_hash
)
2714 ops
->flags
|= FTRACE_OPS_FL_MODIFYING
;
2715 ops
->old_hash
.filter_hash
= old_hash
->filter_hash
;
2716 ops
->old_hash
.notrace_hash
= old_hash
->notrace_hash
;
2717 ftrace_run_update_code(command
);
2718 ops
->old_hash
.filter_hash
= NULL
;
2719 ops
->old_hash
.notrace_hash
= NULL
;
2720 ops
->flags
&= ~FTRACE_OPS_FL_MODIFYING
;
2723 static ftrace_func_t saved_ftrace_func
;
2724 static int ftrace_start_up
;
2726 void __weak
arch_ftrace_trampoline_free(struct ftrace_ops
*ops
)
2730 static void per_cpu_ops_free(struct ftrace_ops
*ops
)
2732 free_percpu(ops
->disabled
);
2735 static void ftrace_startup_enable(int command
)
2737 if (saved_ftrace_func
!= ftrace_trace_function
) {
2738 saved_ftrace_func
= ftrace_trace_function
;
2739 command
|= FTRACE_UPDATE_TRACE_FUNC
;
2742 if (!command
|| !ftrace_enabled
)
2745 ftrace_run_update_code(command
);
2748 static void ftrace_startup_all(int command
)
2750 update_all_ops
= true;
2751 ftrace_startup_enable(command
);
2752 update_all_ops
= false;
2755 static int ftrace_startup(struct ftrace_ops
*ops
, int command
)
2759 if (unlikely(ftrace_disabled
))
2762 ret
= __register_ftrace_function(ops
);
2769 * Note that ftrace probes uses this to start up
2770 * and modify functions it will probe. But we still
2771 * set the ADDING flag for modification, as probes
2772 * do not have trampolines. If they add them in the
2773 * future, then the probes will need to distinguish
2774 * between adding and updating probes.
2776 ops
->flags
|= FTRACE_OPS_FL_ENABLED
| FTRACE_OPS_FL_ADDING
;
2778 ret
= ftrace_hash_ipmodify_enable(ops
);
2780 /* Rollback registration process */
2781 __unregister_ftrace_function(ops
);
2783 ops
->flags
&= ~FTRACE_OPS_FL_ENABLED
;
2787 if (ftrace_hash_rec_enable(ops
, 1))
2788 command
|= FTRACE_UPDATE_CALLS
;
2790 ftrace_startup_enable(command
);
2792 ops
->flags
&= ~FTRACE_OPS_FL_ADDING
;
2797 static int ftrace_shutdown(struct ftrace_ops
*ops
, int command
)
2801 if (unlikely(ftrace_disabled
))
2804 ret
= __unregister_ftrace_function(ops
);
2810 * Just warn in case of unbalance, no need to kill ftrace, it's not
2811 * critical but the ftrace_call callers may be never nopped again after
2812 * further ftrace uses.
2814 WARN_ON_ONCE(ftrace_start_up
< 0);
2816 /* Disabling ipmodify never fails */
2817 ftrace_hash_ipmodify_disable(ops
);
2819 if (ftrace_hash_rec_disable(ops
, 1))
2820 command
|= FTRACE_UPDATE_CALLS
;
2822 ops
->flags
&= ~FTRACE_OPS_FL_ENABLED
;
2824 if (saved_ftrace_func
!= ftrace_trace_function
) {
2825 saved_ftrace_func
= ftrace_trace_function
;
2826 command
|= FTRACE_UPDATE_TRACE_FUNC
;
2829 if (!command
|| !ftrace_enabled
) {
2831 * If these are dynamic or per_cpu ops, they still
2832 * need their data freed. Since, function tracing is
2833 * not currently active, we can just free them
2834 * without synchronizing all CPUs.
2836 if (ops
->flags
& (FTRACE_OPS_FL_DYNAMIC
| FTRACE_OPS_FL_PER_CPU
))
2843 * If the ops uses a trampoline, then it needs to be
2844 * tested first on update.
2846 ops
->flags
|= FTRACE_OPS_FL_REMOVING
;
2849 /* The trampoline logic checks the old hashes */
2850 ops
->old_hash
.filter_hash
= ops
->func_hash
->filter_hash
;
2851 ops
->old_hash
.notrace_hash
= ops
->func_hash
->notrace_hash
;
2853 ftrace_run_update_code(command
);
2856 * If there's no more ops registered with ftrace, run a
2857 * sanity check to make sure all rec flags are cleared.
2859 if (rcu_dereference_protected(ftrace_ops_list
,
2860 lockdep_is_held(&ftrace_lock
)) == &ftrace_list_end
) {
2861 struct ftrace_page
*pg
;
2862 struct dyn_ftrace
*rec
;
2864 do_for_each_ftrace_rec(pg
, rec
) {
2865 if (FTRACE_WARN_ON_ONCE(rec
->flags
& ~FTRACE_FL_DISABLED
))
2866 pr_warn(" %pS flags:%lx\n",
2867 (void *)rec
->ip
, rec
->flags
);
2868 } while_for_each_ftrace_rec();
2871 ops
->old_hash
.filter_hash
= NULL
;
2872 ops
->old_hash
.notrace_hash
= NULL
;
2875 ops
->flags
&= ~FTRACE_OPS_FL_REMOVING
;
2878 * Dynamic ops may be freed, we must make sure that all
2879 * callers are done before leaving this function.
2880 * The same goes for freeing the per_cpu data of the per_cpu
2883 if (ops
->flags
& (FTRACE_OPS_FL_DYNAMIC
| FTRACE_OPS_FL_PER_CPU
)) {
2885 * We need to do a hard force of sched synchronization.
2886 * This is because we use preempt_disable() to do RCU, but
2887 * the function tracers can be called where RCU is not watching
2888 * (like before user_exit()). We can not rely on the RCU
2889 * infrastructure to do the synchronization, thus we must do it
2892 schedule_on_each_cpu(ftrace_sync
);
2895 * When the kernel is preeptive, tasks can be preempted
2896 * while on a ftrace trampoline. Just scheduling a task on
2897 * a CPU is not good enough to flush them. Calling
2898 * synchornize_rcu_tasks() will wait for those tasks to
2899 * execute and either schedule voluntarily or enter user space.
2901 if (IS_ENABLED(CONFIG_PREEMPT
))
2902 synchronize_rcu_tasks();
2905 arch_ftrace_trampoline_free(ops
);
2907 if (ops
->flags
& FTRACE_OPS_FL_PER_CPU
)
2908 per_cpu_ops_free(ops
);
2914 static void ftrace_startup_sysctl(void)
2918 if (unlikely(ftrace_disabled
))
2921 /* Force update next time */
2922 saved_ftrace_func
= NULL
;
2923 /* ftrace_start_up is true if we want ftrace running */
2924 if (ftrace_start_up
) {
2925 command
= FTRACE_UPDATE_CALLS
;
2926 if (ftrace_graph_active
)
2927 command
|= FTRACE_START_FUNC_RET
;
2928 ftrace_startup_enable(command
);
2932 static void ftrace_shutdown_sysctl(void)
2936 if (unlikely(ftrace_disabled
))
2939 /* ftrace_start_up is true if ftrace is running */
2940 if (ftrace_start_up
) {
2941 command
= FTRACE_DISABLE_CALLS
;
2942 if (ftrace_graph_active
)
2943 command
|= FTRACE_STOP_FUNC_RET
;
2944 ftrace_run_update_code(command
);
2948 static u64 ftrace_update_time
;
2949 unsigned long ftrace_update_tot_cnt
;
2951 static inline int ops_traces_mod(struct ftrace_ops
*ops
)
2954 * Filter_hash being empty will default to trace module.
2955 * But notrace hash requires a test of individual module functions.
2957 return ftrace_hash_empty(ops
->func_hash
->filter_hash
) &&
2958 ftrace_hash_empty(ops
->func_hash
->notrace_hash
);
2962 * Check if the current ops references the record.
2964 * If the ops traces all functions, then it was already accounted for.
2965 * If the ops does not trace the current record function, skip it.
2966 * If the ops ignores the function via notrace filter, skip it.
2969 ops_references_rec(struct ftrace_ops
*ops
, struct dyn_ftrace
*rec
)
2971 /* If ops isn't enabled, ignore it */
2972 if (!(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
2975 /* If ops traces all then it includes this function */
2976 if (ops_traces_mod(ops
))
2979 /* The function must be in the filter */
2980 if (!ftrace_hash_empty(ops
->func_hash
->filter_hash
) &&
2981 !__ftrace_lookup_ip(ops
->func_hash
->filter_hash
, rec
->ip
))
2984 /* If in notrace hash, we ignore it too */
2985 if (ftrace_lookup_ip(ops
->func_hash
->notrace_hash
, rec
->ip
))
2991 static int ftrace_update_code(struct module
*mod
, struct ftrace_page
*new_pgs
)
2993 struct ftrace_page
*pg
;
2994 struct dyn_ftrace
*p
;
2996 unsigned long update_cnt
= 0;
2997 unsigned long rec_flags
= 0;
3000 start
= ftrace_now(raw_smp_processor_id());
3003 * When a module is loaded, this function is called to convert
3004 * the calls to mcount in its text to nops, and also to create
3005 * an entry in the ftrace data. Now, if ftrace is activated
3006 * after this call, but before the module sets its text to
3007 * read-only, the modification of enabling ftrace can fail if
3008 * the read-only is done while ftrace is converting the calls.
3009 * To prevent this, the module's records are set as disabled
3010 * and will be enabled after the call to set the module's text
3014 rec_flags
|= FTRACE_FL_DISABLED
;
3016 for (pg
= new_pgs
; pg
; pg
= pg
->next
) {
3018 for (i
= 0; i
< pg
->index
; i
++) {
3020 /* If something went wrong, bail without enabling anything */
3021 if (unlikely(ftrace_disabled
))
3024 p
= &pg
->records
[i
];
3025 p
->flags
= rec_flags
;
3028 * Do the initial record conversion from mcount jump
3029 * to the NOP instructions.
3031 if (!ftrace_code_disable(mod
, p
))
3038 stop
= ftrace_now(raw_smp_processor_id());
3039 ftrace_update_time
= stop
- start
;
3040 ftrace_update_tot_cnt
+= update_cnt
;
3045 static int ftrace_allocate_records(struct ftrace_page
*pg
, int count
)
3050 if (WARN_ON(!count
))
3053 order
= get_count_order(DIV_ROUND_UP(count
, ENTRIES_PER_PAGE
));
3056 * We want to fill as much as possible. No more than a page
3059 while ((PAGE_SIZE
<< order
) / ENTRY_SIZE
>= count
+ ENTRIES_PER_PAGE
)
3063 pg
->records
= (void *)__get_free_pages(GFP_KERNEL
| __GFP_ZERO
, order
);
3066 /* if we can't allocate this size, try something smaller */
3073 cnt
= (PAGE_SIZE
<< order
) / ENTRY_SIZE
;
3082 static struct ftrace_page
*
3083 ftrace_allocate_pages(unsigned long num_to_init
)
3085 struct ftrace_page
*start_pg
;
3086 struct ftrace_page
*pg
;
3093 start_pg
= pg
= kzalloc(sizeof(*pg
), GFP_KERNEL
);
3098 * Try to allocate as much as possible in one continues
3099 * location that fills in all of the space. We want to
3100 * waste as little space as possible.
3103 cnt
= ftrace_allocate_records(pg
, num_to_init
);
3111 pg
->next
= kzalloc(sizeof(*pg
), GFP_KERNEL
);
3123 order
= get_count_order(pg
->size
/ ENTRIES_PER_PAGE
);
3124 free_pages((unsigned long)pg
->records
, order
);
3125 start_pg
= pg
->next
;
3129 pr_info("ftrace: FAILED to allocate memory for functions\n");
3133 #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
3135 struct ftrace_iterator
{
3139 struct ftrace_page
*pg
;
3140 struct dyn_ftrace
*func
;
3141 struct ftrace_func_probe
*probe
;
3142 struct ftrace_func_entry
*probe_entry
;
3143 struct trace_parser parser
;
3144 struct ftrace_hash
*hash
;
3145 struct ftrace_ops
*ops
;
3146 struct trace_array
*tr
;
3147 struct list_head
*mod_list
;
3154 t_probe_next(struct seq_file
*m
, loff_t
*pos
)
3156 struct ftrace_iterator
*iter
= m
->private;
3157 struct trace_array
*tr
= iter
->ops
->private;
3158 struct list_head
*func_probes
;
3159 struct ftrace_hash
*hash
;
3160 struct list_head
*next
;
3161 struct hlist_node
*hnd
= NULL
;
3162 struct hlist_head
*hhd
;
3171 func_probes
= &tr
->func_probes
;
3172 if (list_empty(func_probes
))
3176 next
= func_probes
->next
;
3177 iter
->probe
= list_entry(next
, struct ftrace_func_probe
, list
);
3180 if (iter
->probe_entry
)
3181 hnd
= &iter
->probe_entry
->hlist
;
3183 hash
= iter
->probe
->ops
.func_hash
->filter_hash
;
3184 size
= 1 << hash
->size_bits
;
3187 if (iter
->pidx
>= size
) {
3188 if (iter
->probe
->list
.next
== func_probes
)
3190 next
= iter
->probe
->list
.next
;
3191 iter
->probe
= list_entry(next
, struct ftrace_func_probe
, list
);
3192 hash
= iter
->probe
->ops
.func_hash
->filter_hash
;
3193 size
= 1 << hash
->size_bits
;
3197 hhd
= &hash
->buckets
[iter
->pidx
];
3199 if (hlist_empty(hhd
)) {
3215 if (WARN_ON_ONCE(!hnd
))
3218 iter
->probe_entry
= hlist_entry(hnd
, struct ftrace_func_entry
, hlist
);
3223 static void *t_probe_start(struct seq_file
*m
, loff_t
*pos
)
3225 struct ftrace_iterator
*iter
= m
->private;
3229 if (!(iter
->flags
& FTRACE_ITER_DO_PROBES
))
3232 if (iter
->mod_pos
> *pos
)
3236 iter
->probe_entry
= NULL
;
3238 for (l
= 0; l
<= (*pos
- iter
->mod_pos
); ) {
3239 p
= t_probe_next(m
, &l
);
3246 /* Only set this if we have an item */
3247 iter
->flags
|= FTRACE_ITER_PROBE
;
3253 t_probe_show(struct seq_file
*m
, struct ftrace_iterator
*iter
)
3255 struct ftrace_func_entry
*probe_entry
;
3256 struct ftrace_probe_ops
*probe_ops
;
3257 struct ftrace_func_probe
*probe
;
3259 probe
= iter
->probe
;
3260 probe_entry
= iter
->probe_entry
;
3262 if (WARN_ON_ONCE(!probe
|| !probe_entry
))
3265 probe_ops
= probe
->probe_ops
;
3267 if (probe_ops
->print
)
3268 return probe_ops
->print(m
, probe_entry
->ip
, probe_ops
, probe
->data
);
3270 seq_printf(m
, "%ps:%ps\n", (void *)probe_entry
->ip
,
3271 (void *)probe_ops
->func
);
3277 t_mod_next(struct seq_file
*m
, loff_t
*pos
)
3279 struct ftrace_iterator
*iter
= m
->private;
3280 struct trace_array
*tr
= iter
->tr
;
3285 iter
->mod_list
= iter
->mod_list
->next
;
3287 if (iter
->mod_list
== &tr
->mod_trace
||
3288 iter
->mod_list
== &tr
->mod_notrace
) {
3289 iter
->flags
&= ~FTRACE_ITER_MOD
;
3293 iter
->mod_pos
= *pos
;
3298 static void *t_mod_start(struct seq_file
*m
, loff_t
*pos
)
3300 struct ftrace_iterator
*iter
= m
->private;
3304 if (iter
->func_pos
> *pos
)
3307 iter
->mod_pos
= iter
->func_pos
;
3309 /* probes are only available if tr is set */
3313 for (l
= 0; l
<= (*pos
- iter
->func_pos
); ) {
3314 p
= t_mod_next(m
, &l
);
3319 iter
->flags
&= ~FTRACE_ITER_MOD
;
3320 return t_probe_start(m
, pos
);
3323 /* Only set this if we have an item */
3324 iter
->flags
|= FTRACE_ITER_MOD
;
3330 t_mod_show(struct seq_file
*m
, struct ftrace_iterator
*iter
)
3332 struct ftrace_mod_load
*ftrace_mod
;
3333 struct trace_array
*tr
= iter
->tr
;
3335 if (WARN_ON_ONCE(!iter
->mod_list
) ||
3336 iter
->mod_list
== &tr
->mod_trace
||
3337 iter
->mod_list
== &tr
->mod_notrace
)
3340 ftrace_mod
= list_entry(iter
->mod_list
, struct ftrace_mod_load
, list
);
3342 if (ftrace_mod
->func
)
3343 seq_printf(m
, "%s", ftrace_mod
->func
);
3347 seq_printf(m
, ":mod:%s\n", ftrace_mod
->module
);
3353 t_func_next(struct seq_file
*m
, loff_t
*pos
)
3355 struct ftrace_iterator
*iter
= m
->private;
3356 struct dyn_ftrace
*rec
= NULL
;
3361 if (iter
->idx
>= iter
->pg
->index
) {
3362 if (iter
->pg
->next
) {
3363 iter
->pg
= iter
->pg
->next
;
3368 rec
= &iter
->pg
->records
[iter
->idx
++];
3369 if (((iter
->flags
& (FTRACE_ITER_FILTER
| FTRACE_ITER_NOTRACE
)) &&
3370 !ftrace_lookup_ip(iter
->hash
, rec
->ip
)) ||
3372 ((iter
->flags
& FTRACE_ITER_ENABLED
) &&
3373 !(rec
->flags
& FTRACE_FL_ENABLED
))) {
3383 iter
->pos
= iter
->func_pos
= *pos
;
3390 t_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
3392 struct ftrace_iterator
*iter
= m
->private;
3393 loff_t l
= *pos
; /* t_probe_start() must use original pos */
3396 if (unlikely(ftrace_disabled
))
3399 if (iter
->flags
& FTRACE_ITER_PROBE
)
3400 return t_probe_next(m
, pos
);
3402 if (iter
->flags
& FTRACE_ITER_MOD
)
3403 return t_mod_next(m
, pos
);
3405 if (iter
->flags
& FTRACE_ITER_PRINTALL
) {
3406 /* next must increment pos, and t_probe_start does not */
3408 return t_mod_start(m
, &l
);
3411 ret
= t_func_next(m
, pos
);
3414 return t_mod_start(m
, &l
);
3419 static void reset_iter_read(struct ftrace_iterator
*iter
)
3423 iter
->flags
&= ~(FTRACE_ITER_PRINTALL
| FTRACE_ITER_PROBE
| FTRACE_ITER_MOD
);
3426 static void *t_start(struct seq_file
*m
, loff_t
*pos
)
3428 struct ftrace_iterator
*iter
= m
->private;
3432 mutex_lock(&ftrace_lock
);
3434 if (unlikely(ftrace_disabled
))
3438 * If an lseek was done, then reset and start from beginning.
3440 if (*pos
< iter
->pos
)
3441 reset_iter_read(iter
);
3444 * For set_ftrace_filter reading, if we have the filter
3445 * off, we can short cut and just print out that all
3446 * functions are enabled.
3448 if ((iter
->flags
& (FTRACE_ITER_FILTER
| FTRACE_ITER_NOTRACE
)) &&
3449 ftrace_hash_empty(iter
->hash
)) {
3450 iter
->func_pos
= 1; /* Account for the message */
3452 return t_mod_start(m
, pos
);
3453 iter
->flags
|= FTRACE_ITER_PRINTALL
;
3454 /* reset in case of seek/pread */
3455 iter
->flags
&= ~FTRACE_ITER_PROBE
;
3459 if (iter
->flags
& FTRACE_ITER_MOD
)
3460 return t_mod_start(m
, pos
);
3463 * Unfortunately, we need to restart at ftrace_pages_start
3464 * every time we let go of the ftrace_mutex. This is because
3465 * those pointers can change without the lock.
3467 iter
->pg
= ftrace_pages_start
;
3469 for (l
= 0; l
<= *pos
; ) {
3470 p
= t_func_next(m
, &l
);
3476 return t_mod_start(m
, pos
);
3481 static void t_stop(struct seq_file
*m
, void *p
)
3483 mutex_unlock(&ftrace_lock
);
3487 arch_ftrace_trampoline_func(struct ftrace_ops
*ops
, struct dyn_ftrace
*rec
)
3492 static void add_trampoline_func(struct seq_file
*m
, struct ftrace_ops
*ops
,
3493 struct dyn_ftrace
*rec
)
3497 ptr
= arch_ftrace_trampoline_func(ops
, rec
);
3499 seq_printf(m
, " ->%pS", ptr
);
3502 static int t_show(struct seq_file
*m
, void *v
)
3504 struct ftrace_iterator
*iter
= m
->private;
3505 struct dyn_ftrace
*rec
;
3507 if (iter
->flags
& FTRACE_ITER_PROBE
)
3508 return t_probe_show(m
, iter
);
3510 if (iter
->flags
& FTRACE_ITER_MOD
)
3511 return t_mod_show(m
, iter
);
3513 if (iter
->flags
& FTRACE_ITER_PRINTALL
) {
3514 if (iter
->flags
& FTRACE_ITER_NOTRACE
)
3515 seq_puts(m
, "#### no functions disabled ####\n");
3517 seq_puts(m
, "#### all functions enabled ####\n");
3526 seq_printf(m
, "%ps", (void *)rec
->ip
);
3527 if (iter
->flags
& FTRACE_ITER_ENABLED
) {
3528 struct ftrace_ops
*ops
;
3530 seq_printf(m
, " (%ld)%s%s",
3531 ftrace_rec_count(rec
),
3532 rec
->flags
& FTRACE_FL_REGS
? " R" : " ",
3533 rec
->flags
& FTRACE_FL_IPMODIFY
? " I" : " ");
3534 if (rec
->flags
& FTRACE_FL_TRAMP_EN
) {
3535 ops
= ftrace_find_tramp_ops_any(rec
);
3538 seq_printf(m
, "\ttramp: %pS (%pS)",
3539 (void *)ops
->trampoline
,
3541 add_trampoline_func(m
, ops
, rec
);
3542 ops
= ftrace_find_tramp_ops_next(rec
, ops
);
3545 seq_puts(m
, "\ttramp: ERROR!");
3547 add_trampoline_func(m
, NULL
, rec
);
3556 static const struct seq_operations show_ftrace_seq_ops
= {
3564 ftrace_avail_open(struct inode
*inode
, struct file
*file
)
3566 struct ftrace_iterator
*iter
;
3568 if (unlikely(ftrace_disabled
))
3571 iter
= __seq_open_private(file
, &show_ftrace_seq_ops
, sizeof(*iter
));
3575 iter
->pg
= ftrace_pages_start
;
3576 iter
->ops
= &global_ops
;
3582 ftrace_enabled_open(struct inode
*inode
, struct file
*file
)
3584 struct ftrace_iterator
*iter
;
3586 iter
= __seq_open_private(file
, &show_ftrace_seq_ops
, sizeof(*iter
));
3590 iter
->pg
= ftrace_pages_start
;
3591 iter
->flags
= FTRACE_ITER_ENABLED
;
3592 iter
->ops
= &global_ops
;
3598 * ftrace_regex_open - initialize function tracer filter files
3599 * @ops: The ftrace_ops that hold the hash filters
3600 * @flag: The type of filter to process
3601 * @inode: The inode, usually passed in to your open routine
3602 * @file: The file, usually passed in to your open routine
3604 * ftrace_regex_open() initializes the filter files for the
3605 * @ops. Depending on @flag it may process the filter hash or
3606 * the notrace hash of @ops. With this called from the open
3607 * routine, you can use ftrace_filter_write() for the write
3608 * routine if @flag has FTRACE_ITER_FILTER set, or
3609 * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set.
3610 * tracing_lseek() should be used as the lseek routine, and
3611 * release must call ftrace_regex_release().
3614 ftrace_regex_open(struct ftrace_ops
*ops
, int flag
,
3615 struct inode
*inode
, struct file
*file
)
3617 struct ftrace_iterator
*iter
;
3618 struct ftrace_hash
*hash
;
3619 struct list_head
*mod_head
;
3620 struct trace_array
*tr
= ops
->private;
3623 ftrace_ops_init(ops
);
3625 if (unlikely(ftrace_disabled
))
3628 iter
= kzalloc(sizeof(*iter
), GFP_KERNEL
);
3632 if (trace_parser_get_init(&iter
->parser
, FTRACE_BUFF_MAX
)) {
3641 mutex_lock(&ops
->func_hash
->regex_lock
);
3643 if (flag
& FTRACE_ITER_NOTRACE
) {
3644 hash
= ops
->func_hash
->notrace_hash
;
3645 mod_head
= tr
? &tr
->mod_notrace
: NULL
;
3647 hash
= ops
->func_hash
->filter_hash
;
3648 mod_head
= tr
? &tr
->mod_trace
: NULL
;
3651 iter
->mod_list
= mod_head
;
3653 if (file
->f_mode
& FMODE_WRITE
) {
3654 const int size_bits
= FTRACE_HASH_DEFAULT_BITS
;
3656 if (file
->f_flags
& O_TRUNC
) {
3657 iter
->hash
= alloc_ftrace_hash(size_bits
);
3658 clear_ftrace_mod_list(mod_head
);
3660 iter
->hash
= alloc_and_copy_ftrace_hash(size_bits
, hash
);
3664 trace_parser_put(&iter
->parser
);
3672 if (file
->f_mode
& FMODE_READ
) {
3673 iter
->pg
= ftrace_pages_start
;
3675 ret
= seq_open(file
, &show_ftrace_seq_ops
);
3677 struct seq_file
*m
= file
->private_data
;
3681 free_ftrace_hash(iter
->hash
);
3682 trace_parser_put(&iter
->parser
);
3686 file
->private_data
= iter
;
3689 mutex_unlock(&ops
->func_hash
->regex_lock
);
3695 ftrace_filter_open(struct inode
*inode
, struct file
*file
)
3697 struct ftrace_ops
*ops
= inode
->i_private
;
3699 return ftrace_regex_open(ops
,
3700 FTRACE_ITER_FILTER
| FTRACE_ITER_DO_PROBES
,
3705 ftrace_notrace_open(struct inode
*inode
, struct file
*file
)
3707 struct ftrace_ops
*ops
= inode
->i_private
;
3709 return ftrace_regex_open(ops
, FTRACE_ITER_NOTRACE
,
3713 /* Type for quick search ftrace basic regexes (globs) from filter_parse_regex */
3714 struct ftrace_glob
{
3721 * If symbols in an architecture don't correspond exactly to the user-visible
3722 * name of what they represent, it is possible to define this function to
3723 * perform the necessary adjustments.
3725 char * __weak
arch_ftrace_match_adjust(char *str
, const char *search
)
3730 static int ftrace_match(char *str
, struct ftrace_glob
*g
)
3735 str
= arch_ftrace_match_adjust(str
, g
->search
);
3739 if (strcmp(str
, g
->search
) == 0)
3742 case MATCH_FRONT_ONLY
:
3743 if (strncmp(str
, g
->search
, g
->len
) == 0)
3746 case MATCH_MIDDLE_ONLY
:
3747 if (strstr(str
, g
->search
))
3750 case MATCH_END_ONLY
:
3752 if (slen
>= g
->len
&&
3753 memcmp(str
+ slen
- g
->len
, g
->search
, g
->len
) == 0)
3757 if (glob_match(g
->search
, str
))
3766 enter_record(struct ftrace_hash
*hash
, struct dyn_ftrace
*rec
, int clear_filter
)
3768 struct ftrace_func_entry
*entry
;
3771 entry
= ftrace_lookup_ip(hash
, rec
->ip
);
3773 /* Do nothing if it doesn't exist */
3777 free_hash_entry(hash
, entry
);
3779 /* Do nothing if it exists */
3783 ret
= add_hash_entry(hash
, rec
->ip
);
3789 ftrace_match_record(struct dyn_ftrace
*rec
, struct ftrace_glob
*func_g
,
3790 struct ftrace_glob
*mod_g
, int exclude_mod
)
3792 char str
[KSYM_SYMBOL_LEN
];
3795 kallsyms_lookup(rec
->ip
, NULL
, NULL
, &modname
, str
);
3798 int mod_matches
= (modname
) ? ftrace_match(modname
, mod_g
) : 0;
3800 /* blank module name to match all modules */
3802 /* blank module globbing: modname xor exclude_mod */
3803 if (!exclude_mod
!= !modname
)
3809 * exclude_mod is set to trace everything but the given
3810 * module. If it is set and the module matches, then
3811 * return 0. If it is not set, and the module doesn't match
3812 * also return 0. Otherwise, check the function to see if
3815 if (!mod_matches
== !exclude_mod
)
3818 /* blank search means to match all funcs in the mod */
3823 return ftrace_match(str
, func_g
);
3827 match_records(struct ftrace_hash
*hash
, char *func
, int len
, char *mod
)
3829 struct ftrace_page
*pg
;
3830 struct dyn_ftrace
*rec
;
3831 struct ftrace_glob func_g
= { .type
= MATCH_FULL
};
3832 struct ftrace_glob mod_g
= { .type
= MATCH_FULL
};
3833 struct ftrace_glob
*mod_match
= (mod
) ? &mod_g
: NULL
;
3834 int exclude_mod
= 0;
3837 int clear_filter
= 0;
3840 func_g
.type
= filter_parse_regex(func
, len
, &func_g
.search
,
3842 func_g
.len
= strlen(func_g
.search
);
3846 mod_g
.type
= filter_parse_regex(mod
, strlen(mod
),
3847 &mod_g
.search
, &exclude_mod
);
3848 mod_g
.len
= strlen(mod_g
.search
);
3851 mutex_lock(&ftrace_lock
);
3853 if (unlikely(ftrace_disabled
))
3856 do_for_each_ftrace_rec(pg
, rec
) {
3858 if (rec
->flags
& FTRACE_FL_DISABLED
)
3861 if (ftrace_match_record(rec
, &func_g
, mod_match
, exclude_mod
)) {
3862 ret
= enter_record(hash
, rec
, clear_filter
);
3869 } while_for_each_ftrace_rec();
3871 mutex_unlock(&ftrace_lock
);
3877 ftrace_match_records(struct ftrace_hash
*hash
, char *buff
, int len
)
3879 return match_records(hash
, buff
, len
, NULL
);
3882 static void ftrace_ops_update_code(struct ftrace_ops
*ops
,
3883 struct ftrace_ops_hash
*old_hash
)
3885 struct ftrace_ops
*op
;
3887 if (!ftrace_enabled
)
3890 if (ops
->flags
& FTRACE_OPS_FL_ENABLED
) {
3891 ftrace_run_modify_code(ops
, FTRACE_UPDATE_CALLS
, old_hash
);
3896 * If this is the shared global_ops filter, then we need to
3897 * check if there is another ops that shares it, is enabled.
3898 * If so, we still need to run the modify code.
3900 if (ops
->func_hash
!= &global_ops
.local_hash
)
3903 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
3904 if (op
->func_hash
== &global_ops
.local_hash
&&
3905 op
->flags
& FTRACE_OPS_FL_ENABLED
) {
3906 ftrace_run_modify_code(op
, FTRACE_UPDATE_CALLS
, old_hash
);
3907 /* Only need to do this once */
3910 } while_for_each_ftrace_op(op
);
3913 static int ftrace_hash_move_and_update_ops(struct ftrace_ops
*ops
,
3914 struct ftrace_hash
**orig_hash
,
3915 struct ftrace_hash
*hash
,
3918 struct ftrace_ops_hash old_hash_ops
;
3919 struct ftrace_hash
*old_hash
;
3922 old_hash
= *orig_hash
;
3923 old_hash_ops
.filter_hash
= ops
->func_hash
->filter_hash
;
3924 old_hash_ops
.notrace_hash
= ops
->func_hash
->notrace_hash
;
3925 ret
= ftrace_hash_move(ops
, enable
, orig_hash
, hash
);
3927 ftrace_ops_update_code(ops
, &old_hash_ops
);
3928 free_ftrace_hash_rcu(old_hash
);
3933 static bool module_exists(const char *module
)
3935 /* All modules have the symbol __this_module */
3936 const char this_mod
[] = "__this_module";
3937 const int modname_size
= MAX_PARAM_PREFIX_LEN
+ sizeof(this_mod
) + 1;
3938 char modname
[modname_size
+ 1];
3942 n
= snprintf(modname
, modname_size
+ 1, "%s:%s", module
, this_mod
);
3944 if (n
> modname_size
)
3947 val
= module_kallsyms_lookup_name(modname
);
3951 static int cache_mod(struct trace_array
*tr
,
3952 const char *func
, char *module
, int enable
)
3954 struct ftrace_mod_load
*ftrace_mod
, *n
;
3955 struct list_head
*head
= enable
? &tr
->mod_trace
: &tr
->mod_notrace
;
3958 mutex_lock(&ftrace_lock
);
3960 /* We do not cache inverse filters */
3961 if (func
[0] == '!') {
3965 /* Look to remove this hash */
3966 list_for_each_entry_safe(ftrace_mod
, n
, head
, list
) {
3967 if (strcmp(ftrace_mod
->module
, module
) != 0)
3970 /* no func matches all */
3971 if (strcmp(func
, "*") == 0 ||
3972 (ftrace_mod
->func
&&
3973 strcmp(ftrace_mod
->func
, func
) == 0)) {
3975 free_ftrace_mod(ftrace_mod
);
3983 /* We only care about modules that have not been loaded yet */
3984 if (module_exists(module
))
3987 /* Save this string off, and execute it when the module is loaded */
3988 ret
= ftrace_add_mod(tr
, func
, module
, enable
);
3990 mutex_unlock(&ftrace_lock
);
3996 ftrace_set_regex(struct ftrace_ops
*ops
, unsigned char *buf
, int len
,
3997 int reset
, int enable
);
3999 #ifdef CONFIG_MODULES
4000 static void process_mod_list(struct list_head
*head
, struct ftrace_ops
*ops
,
4001 char *mod
, bool enable
)
4003 struct ftrace_mod_load
*ftrace_mod
, *n
;
4004 struct ftrace_hash
**orig_hash
, *new_hash
;
4005 LIST_HEAD(process_mods
);
4009 mutex_lock(&ops
->func_hash
->regex_lock
);
4012 orig_hash
= &ops
->func_hash
->filter_hash
;
4014 orig_hash
= &ops
->func_hash
->notrace_hash
;
4016 new_hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
,
4019 goto out
; /* warn? */
4021 mutex_lock(&ftrace_lock
);
4023 list_for_each_entry_safe(ftrace_mod
, n
, head
, list
) {
4025 if (strcmp(ftrace_mod
->module
, mod
) != 0)
4028 if (ftrace_mod
->func
)
4029 func
= kstrdup(ftrace_mod
->func
, GFP_KERNEL
);
4031 func
= kstrdup("*", GFP_KERNEL
);
4033 if (!func
) /* warn? */
4036 list_del(&ftrace_mod
->list
);
4037 list_add(&ftrace_mod
->list
, &process_mods
);
4039 /* Use the newly allocated func, as it may be "*" */
4040 kfree(ftrace_mod
->func
);
4041 ftrace_mod
->func
= func
;
4044 mutex_unlock(&ftrace_lock
);
4046 list_for_each_entry_safe(ftrace_mod
, n
, &process_mods
, list
) {
4048 func
= ftrace_mod
->func
;
4050 /* Grabs ftrace_lock, which is why we have this extra step */
4051 match_records(new_hash
, func
, strlen(func
), mod
);
4052 free_ftrace_mod(ftrace_mod
);
4055 if (enable
&& list_empty(head
))
4056 new_hash
->flags
&= ~FTRACE_HASH_FL_MOD
;
4058 mutex_lock(&ftrace_lock
);
4060 ret
= ftrace_hash_move_and_update_ops(ops
, orig_hash
,
4062 mutex_unlock(&ftrace_lock
);
4065 mutex_unlock(&ops
->func_hash
->regex_lock
);
4067 free_ftrace_hash(new_hash
);
4070 static void process_cached_mods(const char *mod_name
)
4072 struct trace_array
*tr
;
4075 mod
= kstrdup(mod_name
, GFP_KERNEL
);
4079 mutex_lock(&trace_types_lock
);
4080 list_for_each_entry(tr
, &ftrace_trace_arrays
, list
) {
4081 if (!list_empty(&tr
->mod_trace
))
4082 process_mod_list(&tr
->mod_trace
, tr
->ops
, mod
, true);
4083 if (!list_empty(&tr
->mod_notrace
))
4084 process_mod_list(&tr
->mod_notrace
, tr
->ops
, mod
, false);
4086 mutex_unlock(&trace_types_lock
);
4093 * We register the module command as a template to show others how
4094 * to register the a command as well.
4098 ftrace_mod_callback(struct trace_array
*tr
, struct ftrace_hash
*hash
,
4099 char *func_orig
, char *cmd
, char *module
, int enable
)
4104 /* match_records() modifies func, and we need the original */
4105 func
= kstrdup(func_orig
, GFP_KERNEL
);
4110 * cmd == 'mod' because we only registered this func
4111 * for the 'mod' ftrace_func_command.
4112 * But if you register one func with multiple commands,
4113 * you can tell which command was used by the cmd
4116 ret
= match_records(hash
, func
, strlen(func
), module
);
4120 return cache_mod(tr
, func_orig
, module
, enable
);
4126 static struct ftrace_func_command ftrace_mod_cmd
= {
4128 .func
= ftrace_mod_callback
,
4131 static int __init
ftrace_mod_cmd_init(void)
4133 return register_ftrace_command(&ftrace_mod_cmd
);
4135 core_initcall(ftrace_mod_cmd_init
);
4137 static void function_trace_probe_call(unsigned long ip
, unsigned long parent_ip
,
4138 struct ftrace_ops
*op
, struct pt_regs
*pt_regs
)
4140 struct ftrace_probe_ops
*probe_ops
;
4141 struct ftrace_func_probe
*probe
;
4143 probe
= container_of(op
, struct ftrace_func_probe
, ops
);
4144 probe_ops
= probe
->probe_ops
;
4147 * Disable preemption for these calls to prevent a RCU grace
4148 * period. This syncs the hash iteration and freeing of items
4149 * on the hash. rcu_read_lock is too dangerous here.
4151 preempt_disable_notrace();
4152 probe_ops
->func(ip
, parent_ip
, probe
->tr
, probe_ops
, probe
->data
);
4153 preempt_enable_notrace();
4156 struct ftrace_func_map
{
4157 struct ftrace_func_entry entry
;
4161 struct ftrace_func_mapper
{
4162 struct ftrace_hash hash
;
4166 * allocate_ftrace_func_mapper - allocate a new ftrace_func_mapper
4168 * Returns a ftrace_func_mapper descriptor that can be used to map ips to data.
4170 struct ftrace_func_mapper
*allocate_ftrace_func_mapper(void)
4172 struct ftrace_hash
*hash
;
4175 * The mapper is simply a ftrace_hash, but since the entries
4176 * in the hash are not ftrace_func_entry type, we define it
4177 * as a separate structure.
4179 hash
= alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
);
4180 return (struct ftrace_func_mapper
*)hash
;
4184 * ftrace_func_mapper_find_ip - Find some data mapped to an ip
4185 * @mapper: The mapper that has the ip maps
4186 * @ip: the instruction pointer to find the data for
4188 * Returns the data mapped to @ip if found otherwise NULL. The return
4189 * is actually the address of the mapper data pointer. The address is
4190 * returned for use cases where the data is no bigger than a long, and
4191 * the user can use the data pointer as its data instead of having to
4192 * allocate more memory for the reference.
4194 void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper
*mapper
,
4197 struct ftrace_func_entry
*entry
;
4198 struct ftrace_func_map
*map
;
4200 entry
= ftrace_lookup_ip(&mapper
->hash
, ip
);
4204 map
= (struct ftrace_func_map
*)entry
;
4209 * ftrace_func_mapper_add_ip - Map some data to an ip
4210 * @mapper: The mapper that has the ip maps
4211 * @ip: The instruction pointer address to map @data to
4212 * @data: The data to map to @ip
4214 * Returns 0 on succes otherwise an error.
4216 int ftrace_func_mapper_add_ip(struct ftrace_func_mapper
*mapper
,
4217 unsigned long ip
, void *data
)
4219 struct ftrace_func_entry
*entry
;
4220 struct ftrace_func_map
*map
;
4222 entry
= ftrace_lookup_ip(&mapper
->hash
, ip
);
4226 map
= kmalloc(sizeof(*map
), GFP_KERNEL
);
4233 __add_hash_entry(&mapper
->hash
, &map
->entry
);
4239 * ftrace_func_mapper_remove_ip - Remove an ip from the mapping
4240 * @mapper: The mapper that has the ip maps
4241 * @ip: The instruction pointer address to remove the data from
4243 * Returns the data if it is found, otherwise NULL.
4244 * Note, if the data pointer is used as the data itself, (see
4245 * ftrace_func_mapper_find_ip(), then the return value may be meaningless,
4246 * if the data pointer was set to zero.
4248 void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper
*mapper
,
4251 struct ftrace_func_entry
*entry
;
4252 struct ftrace_func_map
*map
;
4255 entry
= ftrace_lookup_ip(&mapper
->hash
, ip
);
4259 map
= (struct ftrace_func_map
*)entry
;
4262 remove_hash_entry(&mapper
->hash
, entry
);
4269 * free_ftrace_func_mapper - free a mapping of ips and data
4270 * @mapper: The mapper that has the ip maps
4271 * @free_func: A function to be called on each data item.
4273 * This is used to free the function mapper. The @free_func is optional
4274 * and can be used if the data needs to be freed as well.
4276 void free_ftrace_func_mapper(struct ftrace_func_mapper
*mapper
,
4277 ftrace_mapper_func free_func
)
4279 struct ftrace_func_entry
*entry
;
4280 struct ftrace_func_map
*map
;
4281 struct hlist_head
*hhd
;
4282 int size
= 1 << mapper
->hash
.size_bits
;
4285 if (free_func
&& mapper
->hash
.count
) {
4286 for (i
= 0; i
< size
; i
++) {
4287 hhd
= &mapper
->hash
.buckets
[i
];
4288 hlist_for_each_entry(entry
, hhd
, hlist
) {
4289 map
= (struct ftrace_func_map
*)entry
;
4294 free_ftrace_hash(&mapper
->hash
);
4297 static void release_probe(struct ftrace_func_probe
*probe
)
4299 struct ftrace_probe_ops
*probe_ops
;
4301 mutex_lock(&ftrace_lock
);
4303 WARN_ON(probe
->ref
<= 0);
4305 /* Subtract the ref that was used to protect this instance */
4309 probe_ops
= probe
->probe_ops
;
4311 * Sending zero as ip tells probe_ops to free
4312 * the probe->data itself
4314 if (probe_ops
->free
)
4315 probe_ops
->free(probe_ops
, probe
->tr
, 0, probe
->data
);
4316 list_del(&probe
->list
);
4319 mutex_unlock(&ftrace_lock
);
4322 static void acquire_probe_locked(struct ftrace_func_probe
*probe
)
4325 * Add one ref to keep it from being freed when releasing the
4326 * ftrace_lock mutex.
4332 register_ftrace_function_probe(char *glob
, struct trace_array
*tr
,
4333 struct ftrace_probe_ops
*probe_ops
,
4336 struct ftrace_func_entry
*entry
;
4337 struct ftrace_func_probe
*probe
;
4338 struct ftrace_hash
**orig_hash
;
4339 struct ftrace_hash
*old_hash
;
4340 struct ftrace_hash
*hash
;
4349 /* We do not support '!' for function probes */
4350 if (WARN_ON(glob
[0] == '!'))
4354 mutex_lock(&ftrace_lock
);
4355 /* Check if the probe_ops is already registered */
4356 list_for_each_entry(probe
, &tr
->func_probes
, list
) {
4357 if (probe
->probe_ops
== probe_ops
)
4360 if (&probe
->list
== &tr
->func_probes
) {
4361 probe
= kzalloc(sizeof(*probe
), GFP_KERNEL
);
4363 mutex_unlock(&ftrace_lock
);
4366 probe
->probe_ops
= probe_ops
;
4367 probe
->ops
.func
= function_trace_probe_call
;
4369 ftrace_ops_init(&probe
->ops
);
4370 list_add(&probe
->list
, &tr
->func_probes
);
4373 acquire_probe_locked(probe
);
4375 mutex_unlock(&ftrace_lock
);
4377 mutex_lock(&probe
->ops
.func_hash
->regex_lock
);
4379 orig_hash
= &probe
->ops
.func_hash
->filter_hash
;
4380 old_hash
= *orig_hash
;
4381 hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
, old_hash
);
4383 ret
= ftrace_match_records(hash
, glob
, strlen(glob
));
4385 /* Nothing found? */
4392 size
= 1 << hash
->size_bits
;
4393 for (i
= 0; i
< size
; i
++) {
4394 hlist_for_each_entry(entry
, &hash
->buckets
[i
], hlist
) {
4395 if (ftrace_lookup_ip(old_hash
, entry
->ip
))
4398 * The caller might want to do something special
4399 * for each function we find. We call the callback
4400 * to give the caller an opportunity to do so.
4402 if (probe_ops
->init
) {
4403 ret
= probe_ops
->init(probe_ops
, tr
,
4407 if (probe_ops
->free
&& count
)
4408 probe_ops
->free(probe_ops
, tr
,
4418 mutex_lock(&ftrace_lock
);
4421 /* Nothing was added? */
4426 ret
= ftrace_hash_move_and_update_ops(&probe
->ops
, orig_hash
,
4431 /* One ref for each new function traced */
4432 probe
->ref
+= count
;
4434 if (!(probe
->ops
.flags
& FTRACE_OPS_FL_ENABLED
))
4435 ret
= ftrace_startup(&probe
->ops
, 0);
4438 mutex_unlock(&ftrace_lock
);
4443 mutex_unlock(&probe
->ops
.func_hash
->regex_lock
);
4444 free_ftrace_hash(hash
);
4446 release_probe(probe
);
4451 if (!probe_ops
->free
|| !count
)
4454 /* Failed to do the move, need to call the free functions */
4455 for (i
= 0; i
< size
; i
++) {
4456 hlist_for_each_entry(entry
, &hash
->buckets
[i
], hlist
) {
4457 if (ftrace_lookup_ip(old_hash
, entry
->ip
))
4459 probe_ops
->free(probe_ops
, tr
, entry
->ip
, probe
->data
);
4466 unregister_ftrace_function_probe_func(char *glob
, struct trace_array
*tr
,
4467 struct ftrace_probe_ops
*probe_ops
)
4469 struct ftrace_ops_hash old_hash_ops
;
4470 struct ftrace_func_entry
*entry
;
4471 struct ftrace_func_probe
*probe
;
4472 struct ftrace_glob func_g
;
4473 struct ftrace_hash
**orig_hash
;
4474 struct ftrace_hash
*old_hash
;
4475 struct ftrace_hash
*hash
= NULL
;
4476 struct hlist_node
*tmp
;
4477 struct hlist_head hhd
;
4478 char str
[KSYM_SYMBOL_LEN
];
4480 int i
, ret
= -ENODEV
;
4483 if (!glob
|| !strlen(glob
) || !strcmp(glob
, "*"))
4484 func_g
.search
= NULL
;
4488 func_g
.type
= filter_parse_regex(glob
, strlen(glob
),
4489 &func_g
.search
, ¬);
4490 func_g
.len
= strlen(func_g
.search
);
4491 func_g
.search
= glob
;
4493 /* we do not support '!' for function probes */
4498 mutex_lock(&ftrace_lock
);
4499 /* Check if the probe_ops is already registered */
4500 list_for_each_entry(probe
, &tr
->func_probes
, list
) {
4501 if (probe
->probe_ops
== probe_ops
)
4504 if (&probe
->list
== &tr
->func_probes
)
4505 goto err_unlock_ftrace
;
4508 if (!(probe
->ops
.flags
& FTRACE_OPS_FL_INITIALIZED
))
4509 goto err_unlock_ftrace
;
4511 acquire_probe_locked(probe
);
4513 mutex_unlock(&ftrace_lock
);
4515 mutex_lock(&probe
->ops
.func_hash
->regex_lock
);
4517 orig_hash
= &probe
->ops
.func_hash
->filter_hash
;
4518 old_hash
= *orig_hash
;
4520 if (ftrace_hash_empty(old_hash
))
4523 old_hash_ops
.filter_hash
= old_hash
;
4524 /* Probes only have filters */
4525 old_hash_ops
.notrace_hash
= NULL
;
4528 hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
, old_hash
);
4532 INIT_HLIST_HEAD(&hhd
);
4534 size
= 1 << hash
->size_bits
;
4535 for (i
= 0; i
< size
; i
++) {
4536 hlist_for_each_entry_safe(entry
, tmp
, &hash
->buckets
[i
], hlist
) {
4538 if (func_g
.search
) {
4539 kallsyms_lookup(entry
->ip
, NULL
, NULL
,
4541 if (!ftrace_match(str
, &func_g
))
4545 remove_hash_entry(hash
, entry
);
4546 hlist_add_head(&entry
->hlist
, &hhd
);
4550 /* Nothing found? */
4556 mutex_lock(&ftrace_lock
);
4558 WARN_ON(probe
->ref
< count
);
4560 probe
->ref
-= count
;
4562 if (ftrace_hash_empty(hash
))
4563 ftrace_shutdown(&probe
->ops
, 0);
4565 ret
= ftrace_hash_move_and_update_ops(&probe
->ops
, orig_hash
,
4568 /* still need to update the function call sites */
4569 if (ftrace_enabled
&& !ftrace_hash_empty(hash
))
4570 ftrace_run_modify_code(&probe
->ops
, FTRACE_UPDATE_CALLS
,
4572 synchronize_sched();
4574 hlist_for_each_entry_safe(entry
, tmp
, &hhd
, hlist
) {
4575 hlist_del(&entry
->hlist
);
4576 if (probe_ops
->free
)
4577 probe_ops
->free(probe_ops
, tr
, entry
->ip
, probe
->data
);
4580 mutex_unlock(&ftrace_lock
);
4583 mutex_unlock(&probe
->ops
.func_hash
->regex_lock
);
4584 free_ftrace_hash(hash
);
4586 release_probe(probe
);
4591 mutex_unlock(&ftrace_lock
);
4595 void clear_ftrace_function_probes(struct trace_array
*tr
)
4597 struct ftrace_func_probe
*probe
, *n
;
4599 list_for_each_entry_safe(probe
, n
, &tr
->func_probes
, list
)
4600 unregister_ftrace_function_probe_func(NULL
, tr
, probe
->probe_ops
);
4603 static LIST_HEAD(ftrace_commands
);
4604 static DEFINE_MUTEX(ftrace_cmd_mutex
);
4607 * Currently we only register ftrace commands from __init, so mark this
4610 __init
int register_ftrace_command(struct ftrace_func_command
*cmd
)
4612 struct ftrace_func_command
*p
;
4615 mutex_lock(&ftrace_cmd_mutex
);
4616 list_for_each_entry(p
, &ftrace_commands
, list
) {
4617 if (strcmp(cmd
->name
, p
->name
) == 0) {
4622 list_add(&cmd
->list
, &ftrace_commands
);
4624 mutex_unlock(&ftrace_cmd_mutex
);
4630 * Currently we only unregister ftrace commands from __init, so mark
4633 __init
int unregister_ftrace_command(struct ftrace_func_command
*cmd
)
4635 struct ftrace_func_command
*p
, *n
;
4638 mutex_lock(&ftrace_cmd_mutex
);
4639 list_for_each_entry_safe(p
, n
, &ftrace_commands
, list
) {
4640 if (strcmp(cmd
->name
, p
->name
) == 0) {
4642 list_del_init(&p
->list
);
4647 mutex_unlock(&ftrace_cmd_mutex
);
4652 static int ftrace_process_regex(struct ftrace_iterator
*iter
,
4653 char *buff
, int len
, int enable
)
4655 struct ftrace_hash
*hash
= iter
->hash
;
4656 struct trace_array
*tr
= iter
->ops
->private;
4657 char *func
, *command
, *next
= buff
;
4658 struct ftrace_func_command
*p
;
4661 func
= strsep(&next
, ":");
4664 ret
= ftrace_match_records(hash
, func
, len
);
4674 command
= strsep(&next
, ":");
4676 mutex_lock(&ftrace_cmd_mutex
);
4677 list_for_each_entry(p
, &ftrace_commands
, list
) {
4678 if (strcmp(p
->name
, command
) == 0) {
4679 ret
= p
->func(tr
, hash
, func
, command
, next
, enable
);
4684 mutex_unlock(&ftrace_cmd_mutex
);
4690 ftrace_regex_write(struct file
*file
, const char __user
*ubuf
,
4691 size_t cnt
, loff_t
*ppos
, int enable
)
4693 struct ftrace_iterator
*iter
;
4694 struct trace_parser
*parser
;
4700 if (file
->f_mode
& FMODE_READ
) {
4701 struct seq_file
*m
= file
->private_data
;
4704 iter
= file
->private_data
;
4706 if (unlikely(ftrace_disabled
))
4709 /* iter->hash is a local copy, so we don't need regex_lock */
4711 parser
= &iter
->parser
;
4712 read
= trace_get_user(parser
, ubuf
, cnt
, ppos
);
4714 if (read
>= 0 && trace_parser_loaded(parser
) &&
4715 !trace_parser_cont(parser
)) {
4716 ret
= ftrace_process_regex(iter
, parser
->buffer
,
4717 parser
->idx
, enable
);
4718 trace_parser_clear(parser
);
4729 ftrace_filter_write(struct file
*file
, const char __user
*ubuf
,
4730 size_t cnt
, loff_t
*ppos
)
4732 return ftrace_regex_write(file
, ubuf
, cnt
, ppos
, 1);
4736 ftrace_notrace_write(struct file
*file
, const char __user
*ubuf
,
4737 size_t cnt
, loff_t
*ppos
)
4739 return ftrace_regex_write(file
, ubuf
, cnt
, ppos
, 0);
4743 ftrace_match_addr(struct ftrace_hash
*hash
, unsigned long ip
, int remove
)
4745 struct ftrace_func_entry
*entry
;
4747 if (!ftrace_location(ip
))
4751 entry
= ftrace_lookup_ip(hash
, ip
);
4754 free_hash_entry(hash
, entry
);
4758 return add_hash_entry(hash
, ip
);
4762 ftrace_set_hash(struct ftrace_ops
*ops
, unsigned char *buf
, int len
,
4763 unsigned long ip
, int remove
, int reset
, int enable
)
4765 struct ftrace_hash
**orig_hash
;
4766 struct ftrace_hash
*hash
;
4769 if (unlikely(ftrace_disabled
))
4772 mutex_lock(&ops
->func_hash
->regex_lock
);
4775 orig_hash
= &ops
->func_hash
->filter_hash
;
4777 orig_hash
= &ops
->func_hash
->notrace_hash
;
4780 hash
= alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
);
4782 hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
, *orig_hash
);
4786 goto out_regex_unlock
;
4789 if (buf
&& !ftrace_match_records(hash
, buf
, len
)) {
4791 goto out_regex_unlock
;
4794 ret
= ftrace_match_addr(hash
, ip
, remove
);
4796 goto out_regex_unlock
;
4799 mutex_lock(&ftrace_lock
);
4800 ret
= ftrace_hash_move_and_update_ops(ops
, orig_hash
, hash
, enable
);
4801 mutex_unlock(&ftrace_lock
);
4804 mutex_unlock(&ops
->func_hash
->regex_lock
);
4806 free_ftrace_hash(hash
);
4811 ftrace_set_addr(struct ftrace_ops
*ops
, unsigned long ip
, int remove
,
4812 int reset
, int enable
)
4814 return ftrace_set_hash(ops
, 0, 0, ip
, remove
, reset
, enable
);
4818 * ftrace_set_filter_ip - set a function to filter on in ftrace by address
4819 * @ops - the ops to set the filter with
4820 * @ip - the address to add to or remove from the filter.
4821 * @remove - non zero to remove the ip from the filter
4822 * @reset - non zero to reset all filters before applying this filter.
4824 * Filters denote which functions should be enabled when tracing is enabled
4825 * If @ip is NULL, it failes to update filter.
4827 int ftrace_set_filter_ip(struct ftrace_ops
*ops
, unsigned long ip
,
4828 int remove
, int reset
)
4830 ftrace_ops_init(ops
);
4831 return ftrace_set_addr(ops
, ip
, remove
, reset
, 1);
4833 EXPORT_SYMBOL_GPL(ftrace_set_filter_ip
);
4836 * ftrace_ops_set_global_filter - setup ops to use global filters
4837 * @ops - the ops which will use the global filters
4839 * ftrace users who need global function trace filtering should call this.
4840 * It can set the global filter only if ops were not initialized before.
4842 void ftrace_ops_set_global_filter(struct ftrace_ops
*ops
)
4844 if (ops
->flags
& FTRACE_OPS_FL_INITIALIZED
)
4847 ftrace_ops_init(ops
);
4848 ops
->func_hash
= &global_ops
.local_hash
;
4850 EXPORT_SYMBOL_GPL(ftrace_ops_set_global_filter
);
4853 ftrace_set_regex(struct ftrace_ops
*ops
, unsigned char *buf
, int len
,
4854 int reset
, int enable
)
4856 return ftrace_set_hash(ops
, buf
, len
, 0, 0, reset
, enable
);
4860 * ftrace_set_filter - set a function to filter on in ftrace
4861 * @ops - the ops to set the filter with
4862 * @buf - the string that holds the function filter text.
4863 * @len - the length of the string.
4864 * @reset - non zero to reset all filters before applying this filter.
4866 * Filters denote which functions should be enabled when tracing is enabled.
4867 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
4869 int ftrace_set_filter(struct ftrace_ops
*ops
, unsigned char *buf
,
4872 ftrace_ops_init(ops
);
4873 return ftrace_set_regex(ops
, buf
, len
, reset
, 1);
4875 EXPORT_SYMBOL_GPL(ftrace_set_filter
);
4878 * ftrace_set_notrace - set a function to not trace in ftrace
4879 * @ops - the ops to set the notrace filter with
4880 * @buf - the string that holds the function notrace text.
4881 * @len - the length of the string.
4882 * @reset - non zero to reset all filters before applying this filter.
4884 * Notrace Filters denote which functions should not be enabled when tracing
4885 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
4888 int ftrace_set_notrace(struct ftrace_ops
*ops
, unsigned char *buf
,
4891 ftrace_ops_init(ops
);
4892 return ftrace_set_regex(ops
, buf
, len
, reset
, 0);
4894 EXPORT_SYMBOL_GPL(ftrace_set_notrace
);
4896 * ftrace_set_global_filter - set a function to filter on with global tracers
4897 * @buf - the string that holds the function filter text.
4898 * @len - the length of the string.
4899 * @reset - non zero to reset all filters before applying this filter.
4901 * Filters denote which functions should be enabled when tracing is enabled.
4902 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
4904 void ftrace_set_global_filter(unsigned char *buf
, int len
, int reset
)
4906 ftrace_set_regex(&global_ops
, buf
, len
, reset
, 1);
4908 EXPORT_SYMBOL_GPL(ftrace_set_global_filter
);
4911 * ftrace_set_global_notrace - set a function to not trace with global tracers
4912 * @buf - the string that holds the function notrace text.
4913 * @len - the length of the string.
4914 * @reset - non zero to reset all filters before applying this filter.
4916 * Notrace Filters denote which functions should not be enabled when tracing
4917 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
4920 void ftrace_set_global_notrace(unsigned char *buf
, int len
, int reset
)
4922 ftrace_set_regex(&global_ops
, buf
, len
, reset
, 0);
4924 EXPORT_SYMBOL_GPL(ftrace_set_global_notrace
);
4927 * command line interface to allow users to set filters on boot up.
4929 #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
4930 static char ftrace_notrace_buf
[FTRACE_FILTER_SIZE
] __initdata
;
4931 static char ftrace_filter_buf
[FTRACE_FILTER_SIZE
] __initdata
;
4933 /* Used by function selftest to not test if filter is set */
4934 bool ftrace_filter_param __initdata
;
4936 static int __init
set_ftrace_notrace(char *str
)
4938 ftrace_filter_param
= true;
4939 strlcpy(ftrace_notrace_buf
, str
, FTRACE_FILTER_SIZE
);
4942 __setup("ftrace_notrace=", set_ftrace_notrace
);
4944 static int __init
set_ftrace_filter(char *str
)
4946 ftrace_filter_param
= true;
4947 strlcpy(ftrace_filter_buf
, str
, FTRACE_FILTER_SIZE
);
4950 __setup("ftrace_filter=", set_ftrace_filter
);
4952 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4953 static char ftrace_graph_buf
[FTRACE_FILTER_SIZE
] __initdata
;
4954 static char ftrace_graph_notrace_buf
[FTRACE_FILTER_SIZE
] __initdata
;
4955 static int ftrace_graph_set_hash(struct ftrace_hash
*hash
, char *buffer
);
4957 static int __init
set_graph_function(char *str
)
4959 strlcpy(ftrace_graph_buf
, str
, FTRACE_FILTER_SIZE
);
4962 __setup("ftrace_graph_filter=", set_graph_function
);
4964 static int __init
set_graph_notrace_function(char *str
)
4966 strlcpy(ftrace_graph_notrace_buf
, str
, FTRACE_FILTER_SIZE
);
4969 __setup("ftrace_graph_notrace=", set_graph_notrace_function
);
4971 static int __init
set_graph_max_depth_function(char *str
)
4975 fgraph_max_depth
= simple_strtoul(str
, NULL
, 0);
4978 __setup("ftrace_graph_max_depth=", set_graph_max_depth_function
);
4980 static void __init
set_ftrace_early_graph(char *buf
, int enable
)
4984 struct ftrace_hash
*hash
;
4986 hash
= alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
);
4991 func
= strsep(&buf
, ",");
4992 /* we allow only one expression at a time */
4993 ret
= ftrace_graph_set_hash(hash
, func
);
4995 printk(KERN_DEBUG
"ftrace: function %s not "
4996 "traceable\n", func
);
5000 ftrace_graph_hash
= hash
;
5002 ftrace_graph_notrace_hash
= hash
;
5004 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
5007 ftrace_set_early_filter(struct ftrace_ops
*ops
, char *buf
, int enable
)
5011 ftrace_ops_init(ops
);
5014 func
= strsep(&buf
, ",");
5015 ftrace_set_regex(ops
, func
, strlen(func
), 0, enable
);
5019 static void __init
set_ftrace_early_filters(void)
5021 if (ftrace_filter_buf
[0])
5022 ftrace_set_early_filter(&global_ops
, ftrace_filter_buf
, 1);
5023 if (ftrace_notrace_buf
[0])
5024 ftrace_set_early_filter(&global_ops
, ftrace_notrace_buf
, 0);
5025 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
5026 if (ftrace_graph_buf
[0])
5027 set_ftrace_early_graph(ftrace_graph_buf
, 1);
5028 if (ftrace_graph_notrace_buf
[0])
5029 set_ftrace_early_graph(ftrace_graph_notrace_buf
, 0);
5030 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
5033 int ftrace_regex_release(struct inode
*inode
, struct file
*file
)
5035 struct seq_file
*m
= (struct seq_file
*)file
->private_data
;
5036 struct ftrace_iterator
*iter
;
5037 struct ftrace_hash
**orig_hash
;
5038 struct trace_parser
*parser
;
5042 if (file
->f_mode
& FMODE_READ
) {
5044 seq_release(inode
, file
);
5046 iter
= file
->private_data
;
5048 parser
= &iter
->parser
;
5049 if (trace_parser_loaded(parser
)) {
5050 parser
->buffer
[parser
->idx
] = 0;
5051 ftrace_match_records(iter
->hash
, parser
->buffer
, parser
->idx
);
5054 trace_parser_put(parser
);
5056 mutex_lock(&iter
->ops
->func_hash
->regex_lock
);
5058 if (file
->f_mode
& FMODE_WRITE
) {
5059 filter_hash
= !!(iter
->flags
& FTRACE_ITER_FILTER
);
5062 orig_hash
= &iter
->ops
->func_hash
->filter_hash
;
5063 if (iter
->tr
&& !list_empty(&iter
->tr
->mod_trace
))
5064 iter
->hash
->flags
|= FTRACE_HASH_FL_MOD
;
5066 orig_hash
= &iter
->ops
->func_hash
->notrace_hash
;
5068 mutex_lock(&ftrace_lock
);
5069 ret
= ftrace_hash_move_and_update_ops(iter
->ops
, orig_hash
,
5070 iter
->hash
, filter_hash
);
5071 mutex_unlock(&ftrace_lock
);
5073 /* For read only, the hash is the ops hash */
5077 mutex_unlock(&iter
->ops
->func_hash
->regex_lock
);
5078 free_ftrace_hash(iter
->hash
);
5084 static const struct file_operations ftrace_avail_fops
= {
5085 .open
= ftrace_avail_open
,
5087 .llseek
= seq_lseek
,
5088 .release
= seq_release_private
,
5091 static const struct file_operations ftrace_enabled_fops
= {
5092 .open
= ftrace_enabled_open
,
5094 .llseek
= seq_lseek
,
5095 .release
= seq_release_private
,
5098 static const struct file_operations ftrace_filter_fops
= {
5099 .open
= ftrace_filter_open
,
5101 .write
= ftrace_filter_write
,
5102 .llseek
= tracing_lseek
,
5103 .release
= ftrace_regex_release
,
5106 static const struct file_operations ftrace_notrace_fops
= {
5107 .open
= ftrace_notrace_open
,
5109 .write
= ftrace_notrace_write
,
5110 .llseek
= tracing_lseek
,
5111 .release
= ftrace_regex_release
,
5114 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
5116 static DEFINE_MUTEX(graph_lock
);
5118 struct ftrace_hash
*ftrace_graph_hash
= EMPTY_HASH
;
5119 struct ftrace_hash
*ftrace_graph_notrace_hash
= EMPTY_HASH
;
5121 enum graph_filter_type
{
5122 GRAPH_FILTER_NOTRACE
= 0,
5123 GRAPH_FILTER_FUNCTION
,
5126 #define FTRACE_GRAPH_EMPTY ((void *)1)
5128 struct ftrace_graph_data
{
5129 struct ftrace_hash
*hash
;
5130 struct ftrace_func_entry
*entry
;
5131 int idx
; /* for hash table iteration */
5132 enum graph_filter_type type
;
5133 struct ftrace_hash
*new_hash
;
5134 const struct seq_operations
*seq_ops
;
5135 struct trace_parser parser
;
5139 __g_next(struct seq_file
*m
, loff_t
*pos
)
5141 struct ftrace_graph_data
*fgd
= m
->private;
5142 struct ftrace_func_entry
*entry
= fgd
->entry
;
5143 struct hlist_head
*head
;
5144 int i
, idx
= fgd
->idx
;
5146 if (*pos
>= fgd
->hash
->count
)
5150 hlist_for_each_entry_continue(entry
, hlist
) {
5158 for (i
= idx
; i
< 1 << fgd
->hash
->size_bits
; i
++) {
5159 head
= &fgd
->hash
->buckets
[i
];
5160 hlist_for_each_entry(entry
, head
, hlist
) {
5170 g_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
5173 return __g_next(m
, pos
);
5176 static void *g_start(struct seq_file
*m
, loff_t
*pos
)
5178 struct ftrace_graph_data
*fgd
= m
->private;
5180 mutex_lock(&graph_lock
);
5182 if (fgd
->type
== GRAPH_FILTER_FUNCTION
)
5183 fgd
->hash
= rcu_dereference_protected(ftrace_graph_hash
,
5184 lockdep_is_held(&graph_lock
));
5186 fgd
->hash
= rcu_dereference_protected(ftrace_graph_notrace_hash
,
5187 lockdep_is_held(&graph_lock
));
5189 /* Nothing, tell g_show to print all functions are enabled */
5190 if (ftrace_hash_empty(fgd
->hash
) && !*pos
)
5191 return FTRACE_GRAPH_EMPTY
;
5195 return __g_next(m
, pos
);
5198 static void g_stop(struct seq_file
*m
, void *p
)
5200 mutex_unlock(&graph_lock
);
5203 static int g_show(struct seq_file
*m
, void *v
)
5205 struct ftrace_func_entry
*entry
= v
;
5210 if (entry
== FTRACE_GRAPH_EMPTY
) {
5211 struct ftrace_graph_data
*fgd
= m
->private;
5213 if (fgd
->type
== GRAPH_FILTER_FUNCTION
)
5214 seq_puts(m
, "#### all functions enabled ####\n");
5216 seq_puts(m
, "#### no functions disabled ####\n");
5220 seq_printf(m
, "%ps\n", (void *)entry
->ip
);
5225 static const struct seq_operations ftrace_graph_seq_ops
= {
5233 __ftrace_graph_open(struct inode
*inode
, struct file
*file
,
5234 struct ftrace_graph_data
*fgd
)
5237 struct ftrace_hash
*new_hash
= NULL
;
5239 if (file
->f_mode
& FMODE_WRITE
) {
5240 const int size_bits
= FTRACE_HASH_DEFAULT_BITS
;
5242 if (trace_parser_get_init(&fgd
->parser
, FTRACE_BUFF_MAX
))
5245 if (file
->f_flags
& O_TRUNC
)
5246 new_hash
= alloc_ftrace_hash(size_bits
);
5248 new_hash
= alloc_and_copy_ftrace_hash(size_bits
,
5256 if (file
->f_mode
& FMODE_READ
) {
5257 ret
= seq_open(file
, &ftrace_graph_seq_ops
);
5259 struct seq_file
*m
= file
->private_data
;
5263 free_ftrace_hash(new_hash
);
5267 file
->private_data
= fgd
;
5270 if (ret
< 0 && file
->f_mode
& FMODE_WRITE
)
5271 trace_parser_put(&fgd
->parser
);
5273 fgd
->new_hash
= new_hash
;
5276 * All uses of fgd->hash must be taken with the graph_lock
5277 * held. The graph_lock is going to be released, so force
5278 * fgd->hash to be reinitialized when it is taken again.
5286 ftrace_graph_open(struct inode
*inode
, struct file
*file
)
5288 struct ftrace_graph_data
*fgd
;
5291 if (unlikely(ftrace_disabled
))
5294 fgd
= kmalloc(sizeof(*fgd
), GFP_KERNEL
);
5298 mutex_lock(&graph_lock
);
5300 fgd
->hash
= rcu_dereference_protected(ftrace_graph_hash
,
5301 lockdep_is_held(&graph_lock
));
5302 fgd
->type
= GRAPH_FILTER_FUNCTION
;
5303 fgd
->seq_ops
= &ftrace_graph_seq_ops
;
5305 ret
= __ftrace_graph_open(inode
, file
, fgd
);
5309 mutex_unlock(&graph_lock
);
5314 ftrace_graph_notrace_open(struct inode
*inode
, struct file
*file
)
5316 struct ftrace_graph_data
*fgd
;
5319 if (unlikely(ftrace_disabled
))
5322 fgd
= kmalloc(sizeof(*fgd
), GFP_KERNEL
);
5326 mutex_lock(&graph_lock
);
5328 fgd
->hash
= rcu_dereference_protected(ftrace_graph_notrace_hash
,
5329 lockdep_is_held(&graph_lock
));
5330 fgd
->type
= GRAPH_FILTER_NOTRACE
;
5331 fgd
->seq_ops
= &ftrace_graph_seq_ops
;
5333 ret
= __ftrace_graph_open(inode
, file
, fgd
);
5337 mutex_unlock(&graph_lock
);
5342 ftrace_graph_release(struct inode
*inode
, struct file
*file
)
5344 struct ftrace_graph_data
*fgd
;
5345 struct ftrace_hash
*old_hash
, *new_hash
;
5346 struct trace_parser
*parser
;
5349 if (file
->f_mode
& FMODE_READ
) {
5350 struct seq_file
*m
= file
->private_data
;
5353 seq_release(inode
, file
);
5355 fgd
= file
->private_data
;
5359 if (file
->f_mode
& FMODE_WRITE
) {
5361 parser
= &fgd
->parser
;
5363 if (trace_parser_loaded((parser
))) {
5364 parser
->buffer
[parser
->idx
] = 0;
5365 ret
= ftrace_graph_set_hash(fgd
->new_hash
,
5369 trace_parser_put(parser
);
5371 new_hash
= __ftrace_hash_move(fgd
->new_hash
);
5377 mutex_lock(&graph_lock
);
5379 if (fgd
->type
== GRAPH_FILTER_FUNCTION
) {
5380 old_hash
= rcu_dereference_protected(ftrace_graph_hash
,
5381 lockdep_is_held(&graph_lock
));
5382 rcu_assign_pointer(ftrace_graph_hash
, new_hash
);
5384 old_hash
= rcu_dereference_protected(ftrace_graph_notrace_hash
,
5385 lockdep_is_held(&graph_lock
));
5386 rcu_assign_pointer(ftrace_graph_notrace_hash
, new_hash
);
5389 mutex_unlock(&graph_lock
);
5391 /* Wait till all users are no longer using the old hash */
5392 synchronize_sched();
5394 free_ftrace_hash(old_hash
);
5398 free_ftrace_hash(fgd
->new_hash
);
5405 ftrace_graph_set_hash(struct ftrace_hash
*hash
, char *buffer
)
5407 struct ftrace_glob func_g
;
5408 struct dyn_ftrace
*rec
;
5409 struct ftrace_page
*pg
;
5410 struct ftrace_func_entry
*entry
;
5415 func_g
.type
= filter_parse_regex(buffer
, strlen(buffer
),
5416 &func_g
.search
, ¬);
5418 func_g
.len
= strlen(func_g
.search
);
5420 mutex_lock(&ftrace_lock
);
5422 if (unlikely(ftrace_disabled
)) {
5423 mutex_unlock(&ftrace_lock
);
5427 do_for_each_ftrace_rec(pg
, rec
) {
5429 if (rec
->flags
& FTRACE_FL_DISABLED
)
5432 if (ftrace_match_record(rec
, &func_g
, NULL
, 0)) {
5433 entry
= ftrace_lookup_ip(hash
, rec
->ip
);
5440 if (add_hash_entry(hash
, rec
->ip
) < 0)
5444 free_hash_entry(hash
, entry
);
5449 } while_for_each_ftrace_rec();
5451 mutex_unlock(&ftrace_lock
);
5460 ftrace_graph_write(struct file
*file
, const char __user
*ubuf
,
5461 size_t cnt
, loff_t
*ppos
)
5463 ssize_t read
, ret
= 0;
5464 struct ftrace_graph_data
*fgd
= file
->private_data
;
5465 struct trace_parser
*parser
;
5470 /* Read mode uses seq functions */
5471 if (file
->f_mode
& FMODE_READ
) {
5472 struct seq_file
*m
= file
->private_data
;
5476 parser
= &fgd
->parser
;
5478 read
= trace_get_user(parser
, ubuf
, cnt
, ppos
);
5480 if (read
>= 0 && trace_parser_loaded(parser
) &&
5481 !trace_parser_cont(parser
)) {
5483 ret
= ftrace_graph_set_hash(fgd
->new_hash
,
5485 trace_parser_clear(parser
);
5494 static const struct file_operations ftrace_graph_fops
= {
5495 .open
= ftrace_graph_open
,
5497 .write
= ftrace_graph_write
,
5498 .llseek
= tracing_lseek
,
5499 .release
= ftrace_graph_release
,
5502 static const struct file_operations ftrace_graph_notrace_fops
= {
5503 .open
= ftrace_graph_notrace_open
,
5505 .write
= ftrace_graph_write
,
5506 .llseek
= tracing_lseek
,
5507 .release
= ftrace_graph_release
,
5509 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
5511 void ftrace_create_filter_files(struct ftrace_ops
*ops
,
5512 struct dentry
*parent
)
5515 trace_create_file("set_ftrace_filter", 0644, parent
,
5516 ops
, &ftrace_filter_fops
);
5518 trace_create_file("set_ftrace_notrace", 0644, parent
,
5519 ops
, &ftrace_notrace_fops
);
5523 * The name "destroy_filter_files" is really a misnomer. Although
5524 * in the future, it may actualy delete the files, but this is
5525 * really intended to make sure the ops passed in are disabled
5526 * and that when this function returns, the caller is free to
5529 * The "destroy" name is only to match the "create" name that this
5530 * should be paired with.
5532 void ftrace_destroy_filter_files(struct ftrace_ops
*ops
)
5534 mutex_lock(&ftrace_lock
);
5535 if (ops
->flags
& FTRACE_OPS_FL_ENABLED
)
5536 ftrace_shutdown(ops
, 0);
5537 ops
->flags
|= FTRACE_OPS_FL_DELETED
;
5538 mutex_unlock(&ftrace_lock
);
5541 static __init
int ftrace_init_dyn_tracefs(struct dentry
*d_tracer
)
5544 trace_create_file("available_filter_functions", 0444,
5545 d_tracer
, NULL
, &ftrace_avail_fops
);
5547 trace_create_file("enabled_functions", 0444,
5548 d_tracer
, NULL
, &ftrace_enabled_fops
);
5550 ftrace_create_filter_files(&global_ops
, d_tracer
);
5552 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
5553 trace_create_file("set_graph_function", 0444, d_tracer
,
5555 &ftrace_graph_fops
);
5556 trace_create_file("set_graph_notrace", 0444, d_tracer
,
5558 &ftrace_graph_notrace_fops
);
5559 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
5564 static int ftrace_cmp_ips(const void *a
, const void *b
)
5566 const unsigned long *ipa
= a
;
5567 const unsigned long *ipb
= b
;
5576 static int ftrace_process_locs(struct module
*mod
,
5577 unsigned long *start
,
5580 struct ftrace_page
*start_pg
;
5581 struct ftrace_page
*pg
;
5582 struct dyn_ftrace
*rec
;
5583 unsigned long count
;
5586 unsigned long flags
= 0; /* Shut up gcc */
5589 count
= end
- start
;
5594 sort(start
, count
, sizeof(*start
),
5595 ftrace_cmp_ips
, NULL
);
5597 start_pg
= ftrace_allocate_pages(count
);
5601 mutex_lock(&ftrace_lock
);
5604 * Core and each module needs their own pages, as
5605 * modules will free them when they are removed.
5606 * Force a new page to be allocated for modules.
5609 WARN_ON(ftrace_pages
|| ftrace_pages_start
);
5610 /* First initialization */
5611 ftrace_pages
= ftrace_pages_start
= start_pg
;
5616 if (WARN_ON(ftrace_pages
->next
)) {
5617 /* Hmm, we have free pages? */
5618 while (ftrace_pages
->next
)
5619 ftrace_pages
= ftrace_pages
->next
;
5622 ftrace_pages
->next
= start_pg
;
5628 addr
= ftrace_call_adjust(*p
++);
5630 * Some architecture linkers will pad between
5631 * the different mcount_loc sections of different
5632 * object files to satisfy alignments.
5633 * Skip any NULL pointers.
5638 if (pg
->index
== pg
->size
) {
5639 /* We should have allocated enough */
5640 if (WARN_ON(!pg
->next
))
5645 rec
= &pg
->records
[pg
->index
++];
5649 /* We should have used all pages */
5652 /* Assign the last page to ftrace_pages */
5656 * We only need to disable interrupts on start up
5657 * because we are modifying code that an interrupt
5658 * may execute, and the modification is not atomic.
5659 * But for modules, nothing runs the code we modify
5660 * until we are finished with it, and there's no
5661 * reason to cause large interrupt latencies while we do it.
5664 local_irq_save(flags
);
5665 ftrace_update_code(mod
, start_pg
);
5667 local_irq_restore(flags
);
5670 mutex_unlock(&ftrace_lock
);
5675 #ifdef CONFIG_MODULES
5677 #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
5679 static int referenced_filters(struct dyn_ftrace
*rec
)
5681 struct ftrace_ops
*ops
;
5684 for (ops
= ftrace_ops_list
; ops
!= &ftrace_list_end
; ops
= ops
->next
) {
5685 if (ops_references_rec(ops
, rec
))
5693 clear_mod_from_hash(struct ftrace_page
*pg
, struct ftrace_hash
*hash
)
5695 struct ftrace_func_entry
*entry
;
5696 struct dyn_ftrace
*rec
;
5699 if (ftrace_hash_empty(hash
))
5702 for (i
= 0; i
< pg
->index
; i
++) {
5703 rec
= &pg
->records
[i
];
5704 entry
= __ftrace_lookup_ip(hash
, rec
->ip
);
5706 * Do not allow this rec to match again.
5707 * Yeah, it may waste some memory, but will be removed
5708 * if/when the hash is modified again.
5715 /* Clear any records from hashs */
5716 static void clear_mod_from_hashes(struct ftrace_page
*pg
)
5718 struct trace_array
*tr
;
5720 mutex_lock(&trace_types_lock
);
5721 list_for_each_entry(tr
, &ftrace_trace_arrays
, list
) {
5722 if (!tr
->ops
|| !tr
->ops
->func_hash
)
5724 mutex_lock(&tr
->ops
->func_hash
->regex_lock
);
5725 clear_mod_from_hash(pg
, tr
->ops
->func_hash
->filter_hash
);
5726 clear_mod_from_hash(pg
, tr
->ops
->func_hash
->notrace_hash
);
5727 mutex_unlock(&tr
->ops
->func_hash
->regex_lock
);
5729 mutex_unlock(&trace_types_lock
);
5732 void ftrace_release_mod(struct module
*mod
)
5734 struct dyn_ftrace
*rec
;
5735 struct ftrace_page
**last_pg
;
5736 struct ftrace_page
*tmp_page
= NULL
;
5737 struct ftrace_page
*pg
;
5740 mutex_lock(&ftrace_lock
);
5742 if (ftrace_disabled
)
5746 * Each module has its own ftrace_pages, remove
5747 * them from the list.
5749 last_pg
= &ftrace_pages_start
;
5750 for (pg
= ftrace_pages_start
; pg
; pg
= *last_pg
) {
5751 rec
= &pg
->records
[0];
5752 if (within_module_core(rec
->ip
, mod
)) {
5754 * As core pages are first, the first
5755 * page should never be a module page.
5757 if (WARN_ON(pg
== ftrace_pages_start
))
5760 /* Check if we are deleting the last page */
5761 if (pg
== ftrace_pages
)
5762 ftrace_pages
= next_to_ftrace_page(last_pg
);
5764 ftrace_update_tot_cnt
-= pg
->index
;
5765 *last_pg
= pg
->next
;
5767 pg
->next
= tmp_page
;
5770 last_pg
= &pg
->next
;
5773 mutex_unlock(&ftrace_lock
);
5775 for (pg
= tmp_page
; pg
; pg
= tmp_page
) {
5777 /* Needs to be called outside of ftrace_lock */
5778 clear_mod_from_hashes(pg
);
5780 order
= get_count_order(pg
->size
/ ENTRIES_PER_PAGE
);
5781 free_pages((unsigned long)pg
->records
, order
);
5782 tmp_page
= pg
->next
;
5787 void ftrace_module_enable(struct module
*mod
)
5789 struct dyn_ftrace
*rec
;
5790 struct ftrace_page
*pg
;
5792 mutex_lock(&ftrace_lock
);
5794 if (ftrace_disabled
)
5798 * If the tracing is enabled, go ahead and enable the record.
5800 * The reason not to enable the record immediatelly is the
5801 * inherent check of ftrace_make_nop/ftrace_make_call for
5802 * correct previous instructions. Making first the NOP
5803 * conversion puts the module to the correct state, thus
5804 * passing the ftrace_make_call check.
5806 * We also delay this to after the module code already set the
5807 * text to read-only, as we now need to set it back to read-write
5808 * so that we can modify the text.
5810 if (ftrace_start_up
)
5811 ftrace_arch_code_modify_prepare();
5813 do_for_each_ftrace_rec(pg
, rec
) {
5816 * do_for_each_ftrace_rec() is a double loop.
5817 * module text shares the pg. If a record is
5818 * not part of this module, then skip this pg,
5819 * which the "break" will do.
5821 if (!within_module_core(rec
->ip
, mod
))
5827 * When adding a module, we need to check if tracers are
5828 * currently enabled and if they are, and can trace this record,
5829 * we need to enable the module functions as well as update the
5830 * reference counts for those function records.
5832 if (ftrace_start_up
)
5833 cnt
+= referenced_filters(rec
);
5835 /* This clears FTRACE_FL_DISABLED */
5838 if (ftrace_start_up
&& cnt
) {
5839 int failed
= __ftrace_replace_code(rec
, 1);
5841 ftrace_bug(failed
, rec
);
5846 } while_for_each_ftrace_rec();
5849 if (ftrace_start_up
)
5850 ftrace_arch_code_modify_post_process();
5853 mutex_unlock(&ftrace_lock
);
5855 process_cached_mods(mod
->name
);
5858 void ftrace_module_init(struct module
*mod
)
5860 if (ftrace_disabled
|| !mod
->num_ftrace_callsites
)
5863 ftrace_process_locs(mod
, mod
->ftrace_callsites
,
5864 mod
->ftrace_callsites
+ mod
->num_ftrace_callsites
);
5866 #endif /* CONFIG_MODULES */
5868 void __init
ftrace_free_init_mem(void)
5870 unsigned long start
= (unsigned long)(&__init_begin
);
5871 unsigned long end
= (unsigned long)(&__init_end
);
5872 struct ftrace_page
**last_pg
= &ftrace_pages_start
;
5873 struct ftrace_page
*pg
;
5874 struct dyn_ftrace
*rec
;
5875 struct dyn_ftrace key
;
5879 key
.flags
= end
; /* overload flags, as it is unsigned long */
5881 mutex_lock(&ftrace_lock
);
5883 for (pg
= ftrace_pages_start
; pg
; last_pg
= &pg
->next
, pg
= *last_pg
) {
5884 if (end
< pg
->records
[0].ip
||
5885 start
>= (pg
->records
[pg
->index
- 1].ip
+ MCOUNT_INSN_SIZE
))
5888 rec
= bsearch(&key
, pg
->records
, pg
->index
,
5889 sizeof(struct dyn_ftrace
),
5894 ftrace_update_tot_cnt
--;
5896 *last_pg
= pg
->next
;
5897 order
= get_count_order(pg
->size
/ ENTRIES_PER_PAGE
);
5898 free_pages((unsigned long)pg
->records
, order
);
5900 pg
= container_of(last_pg
, struct ftrace_page
, next
);
5905 memmove(rec
, rec
+ 1,
5906 (pg
->index
- (rec
- pg
->records
)) * sizeof(*rec
));
5907 /* More than one function may be in this block */
5910 mutex_unlock(&ftrace_lock
);
5913 void __init
ftrace_init(void)
5915 extern unsigned long __start_mcount_loc
[];
5916 extern unsigned long __stop_mcount_loc
[];
5917 unsigned long count
, flags
;
5920 local_irq_save(flags
);
5921 ret
= ftrace_dyn_arch_init();
5922 local_irq_restore(flags
);
5926 count
= __stop_mcount_loc
- __start_mcount_loc
;
5928 pr_info("ftrace: No functions to be traced?\n");
5932 pr_info("ftrace: allocating %ld entries in %ld pages\n",
5933 count
, count
/ ENTRIES_PER_PAGE
+ 1);
5935 last_ftrace_enabled
= ftrace_enabled
= 1;
5937 ret
= ftrace_process_locs(NULL
,
5941 set_ftrace_early_filters();
5945 ftrace_disabled
= 1;
5948 /* Do nothing if arch does not support this */
5949 void __weak
arch_ftrace_update_trampoline(struct ftrace_ops
*ops
)
5953 static void ftrace_update_trampoline(struct ftrace_ops
*ops
)
5955 arch_ftrace_update_trampoline(ops
);
5958 void ftrace_init_trace_array(struct trace_array
*tr
)
5960 INIT_LIST_HEAD(&tr
->func_probes
);
5961 INIT_LIST_HEAD(&tr
->mod_trace
);
5962 INIT_LIST_HEAD(&tr
->mod_notrace
);
5966 static struct ftrace_ops global_ops
= {
5967 .func
= ftrace_stub
,
5968 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
|
5969 FTRACE_OPS_FL_INITIALIZED
|
5973 static int __init
ftrace_nodyn_init(void)
5978 core_initcall(ftrace_nodyn_init
);
5980 static inline int ftrace_init_dyn_tracefs(struct dentry
*d_tracer
) { return 0; }
5981 static inline void ftrace_startup_enable(int command
) { }
5982 static inline void ftrace_startup_all(int command
) { }
5983 /* Keep as macros so we do not need to define the commands */
5984 # define ftrace_startup(ops, command) \
5986 int ___ret = __register_ftrace_function(ops); \
5988 (ops)->flags |= FTRACE_OPS_FL_ENABLED; \
5991 # define ftrace_shutdown(ops, command) \
5993 int ___ret = __unregister_ftrace_function(ops); \
5995 (ops)->flags &= ~FTRACE_OPS_FL_ENABLED; \
5999 # define ftrace_startup_sysctl() do { } while (0)
6000 # define ftrace_shutdown_sysctl() do { } while (0)
6003 ftrace_ops_test(struct ftrace_ops
*ops
, unsigned long ip
, void *regs
)
6008 static void ftrace_update_trampoline(struct ftrace_ops
*ops
)
6012 #endif /* CONFIG_DYNAMIC_FTRACE */
6014 __init
void ftrace_init_global_array_ops(struct trace_array
*tr
)
6016 tr
->ops
= &global_ops
;
6017 tr
->ops
->private = tr
;
6018 ftrace_init_trace_array(tr
);
6021 void ftrace_init_array_ops(struct trace_array
*tr
, ftrace_func_t func
)
6023 /* If we filter on pids, update to use the pid function */
6024 if (tr
->flags
& TRACE_ARRAY_FL_GLOBAL
) {
6025 if (WARN_ON(tr
->ops
->func
!= ftrace_stub
))
6026 printk("ftrace ops had %pS for function\n",
6029 tr
->ops
->func
= func
;
6030 tr
->ops
->private = tr
;
6033 void ftrace_reset_array_ops(struct trace_array
*tr
)
6035 tr
->ops
->func
= ftrace_stub
;
6039 __ftrace_ops_list_func(unsigned long ip
, unsigned long parent_ip
,
6040 struct ftrace_ops
*ignored
, struct pt_regs
*regs
)
6042 struct ftrace_ops
*op
;
6045 bit
= trace_test_and_set_recursion(TRACE_LIST_START
, TRACE_LIST_MAX
);
6050 * Some of the ops may be dynamically allocated,
6051 * they must be freed after a synchronize_sched().
6053 preempt_disable_notrace();
6055 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
6057 * Check the following for each ops before calling their func:
6058 * if RCU flag is set, then rcu_is_watching() must be true
6059 * if PER_CPU is set, then ftrace_function_local_disable()
6061 * Otherwise test if the ip matches the ops filter
6063 * If any of the above fails then the op->func() is not executed.
6065 if ((!(op
->flags
& FTRACE_OPS_FL_RCU
) || rcu_is_watching()) &&
6066 (!(op
->flags
& FTRACE_OPS_FL_PER_CPU
) ||
6067 !ftrace_function_local_disabled(op
)) &&
6068 ftrace_ops_test(op
, ip
, regs
)) {
6070 if (FTRACE_WARN_ON(!op
->func
)) {
6071 pr_warn("op=%p %pS\n", op
, op
);
6074 op
->func(ip
, parent_ip
, op
, regs
);
6076 } while_for_each_ftrace_op(op
);
6078 preempt_enable_notrace();
6079 trace_clear_recursion(bit
);
6083 * Some archs only support passing ip and parent_ip. Even though
6084 * the list function ignores the op parameter, we do not want any
6085 * C side effects, where a function is called without the caller
6086 * sending a third parameter.
6087 * Archs are to support both the regs and ftrace_ops at the same time.
6088 * If they support ftrace_ops, it is assumed they support regs.
6089 * If call backs want to use regs, they must either check for regs
6090 * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS.
6091 * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved.
6092 * An architecture can pass partial regs with ftrace_ops and still
6093 * set the ARCH_SUPPORTS_FTRACE_OPS.
6095 #if ARCH_SUPPORTS_FTRACE_OPS
6096 static void ftrace_ops_list_func(unsigned long ip
, unsigned long parent_ip
,
6097 struct ftrace_ops
*op
, struct pt_regs
*regs
)
6099 __ftrace_ops_list_func(ip
, parent_ip
, NULL
, regs
);
6102 static void ftrace_ops_no_ops(unsigned long ip
, unsigned long parent_ip
)
6104 __ftrace_ops_list_func(ip
, parent_ip
, NULL
, NULL
);
6109 * If there's only one function registered but it does not support
6110 * recursion, needs RCU protection and/or requires per cpu handling, then
6111 * this function will be called by the mcount trampoline.
6113 static void ftrace_ops_assist_func(unsigned long ip
, unsigned long parent_ip
,
6114 struct ftrace_ops
*op
, struct pt_regs
*regs
)
6118 if ((op
->flags
& FTRACE_OPS_FL_RCU
) && !rcu_is_watching())
6121 bit
= trace_test_and_set_recursion(TRACE_LIST_START
, TRACE_LIST_MAX
);
6125 preempt_disable_notrace();
6127 if (!(op
->flags
& FTRACE_OPS_FL_PER_CPU
) ||
6128 !ftrace_function_local_disabled(op
)) {
6129 op
->func(ip
, parent_ip
, op
, regs
);
6132 preempt_enable_notrace();
6133 trace_clear_recursion(bit
);
6137 * ftrace_ops_get_func - get the function a trampoline should call
6138 * @ops: the ops to get the function for
6140 * Normally the mcount trampoline will call the ops->func, but there
6141 * are times that it should not. For example, if the ops does not
6142 * have its own recursion protection, then it should call the
6143 * ftrace_ops_assist_func() instead.
6145 * Returns the function that the trampoline should call for @ops.
6147 ftrace_func_t
ftrace_ops_get_func(struct ftrace_ops
*ops
)
6150 * If the function does not handle recursion, needs to be RCU safe,
6151 * or does per cpu logic, then we need to call the assist handler.
6153 if (!(ops
->flags
& FTRACE_OPS_FL_RECURSION_SAFE
) ||
6154 ops
->flags
& (FTRACE_OPS_FL_RCU
| FTRACE_OPS_FL_PER_CPU
))
6155 return ftrace_ops_assist_func
;
6161 ftrace_filter_pid_sched_switch_probe(void *data
, bool preempt
,
6162 struct task_struct
*prev
, struct task_struct
*next
)
6164 struct trace_array
*tr
= data
;
6165 struct trace_pid_list
*pid_list
;
6167 pid_list
= rcu_dereference_sched(tr
->function_pids
);
6169 this_cpu_write(tr
->trace_buffer
.data
->ftrace_ignore_pid
,
6170 trace_ignore_this_task(pid_list
, next
));
6174 ftrace_pid_follow_sched_process_fork(void *data
,
6175 struct task_struct
*self
,
6176 struct task_struct
*task
)
6178 struct trace_pid_list
*pid_list
;
6179 struct trace_array
*tr
= data
;
6181 pid_list
= rcu_dereference_sched(tr
->function_pids
);
6182 trace_filter_add_remove_task(pid_list
, self
, task
);
6186 ftrace_pid_follow_sched_process_exit(void *data
, struct task_struct
*task
)
6188 struct trace_pid_list
*pid_list
;
6189 struct trace_array
*tr
= data
;
6191 pid_list
= rcu_dereference_sched(tr
->function_pids
);
6192 trace_filter_add_remove_task(pid_list
, NULL
, task
);
6195 void ftrace_pid_follow_fork(struct trace_array
*tr
, bool enable
)
6198 register_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork
,
6200 register_trace_sched_process_exit(ftrace_pid_follow_sched_process_exit
,
6203 unregister_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork
,
6205 unregister_trace_sched_process_exit(ftrace_pid_follow_sched_process_exit
,
6210 static void clear_ftrace_pids(struct trace_array
*tr
)
6212 struct trace_pid_list
*pid_list
;
6215 pid_list
= rcu_dereference_protected(tr
->function_pids
,
6216 lockdep_is_held(&ftrace_lock
));
6220 unregister_trace_sched_switch(ftrace_filter_pid_sched_switch_probe
, tr
);
6222 for_each_possible_cpu(cpu
)
6223 per_cpu_ptr(tr
->trace_buffer
.data
, cpu
)->ftrace_ignore_pid
= false;
6225 rcu_assign_pointer(tr
->function_pids
, NULL
);
6227 /* Wait till all users are no longer using pid filtering */
6228 synchronize_sched();
6230 trace_free_pid_list(pid_list
);
6233 void ftrace_clear_pids(struct trace_array
*tr
)
6235 mutex_lock(&ftrace_lock
);
6237 clear_ftrace_pids(tr
);
6239 mutex_unlock(&ftrace_lock
);
6242 static void ftrace_pid_reset(struct trace_array
*tr
)
6244 mutex_lock(&ftrace_lock
);
6245 clear_ftrace_pids(tr
);
6247 ftrace_update_pid_func();
6248 ftrace_startup_all(0);
6250 mutex_unlock(&ftrace_lock
);
6253 /* Greater than any max PID */
6254 #define FTRACE_NO_PIDS (void *)(PID_MAX_LIMIT + 1)
6256 static void *fpid_start(struct seq_file
*m
, loff_t
*pos
)
6259 struct trace_pid_list
*pid_list
;
6260 struct trace_array
*tr
= m
->private;
6262 mutex_lock(&ftrace_lock
);
6263 rcu_read_lock_sched();
6265 pid_list
= rcu_dereference_sched(tr
->function_pids
);
6268 return !(*pos
) ? FTRACE_NO_PIDS
: NULL
;
6270 return trace_pid_start(pid_list
, pos
);
6273 static void *fpid_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
6275 struct trace_array
*tr
= m
->private;
6276 struct trace_pid_list
*pid_list
= rcu_dereference_sched(tr
->function_pids
);
6278 if (v
== FTRACE_NO_PIDS
)
6281 return trace_pid_next(pid_list
, v
, pos
);
6284 static void fpid_stop(struct seq_file
*m
, void *p
)
6287 rcu_read_unlock_sched();
6288 mutex_unlock(&ftrace_lock
);
6291 static int fpid_show(struct seq_file
*m
, void *v
)
6293 if (v
== FTRACE_NO_PIDS
) {
6294 seq_puts(m
, "no pid\n");
6298 return trace_pid_show(m
, v
);
6301 static const struct seq_operations ftrace_pid_sops
= {
6302 .start
= fpid_start
,
6309 ftrace_pid_open(struct inode
*inode
, struct file
*file
)
6311 struct trace_array
*tr
= inode
->i_private
;
6315 if (trace_array_get(tr
) < 0)
6318 if ((file
->f_mode
& FMODE_WRITE
) &&
6319 (file
->f_flags
& O_TRUNC
))
6320 ftrace_pid_reset(tr
);
6322 ret
= seq_open(file
, &ftrace_pid_sops
);
6324 trace_array_put(tr
);
6326 m
= file
->private_data
;
6327 /* copy tr over to seq ops */
6334 static void ignore_task_cpu(void *data
)
6336 struct trace_array
*tr
= data
;
6337 struct trace_pid_list
*pid_list
;
6340 * This function is called by on_each_cpu() while the
6341 * event_mutex is held.
6343 pid_list
= rcu_dereference_protected(tr
->function_pids
,
6344 mutex_is_locked(&ftrace_lock
));
6346 this_cpu_write(tr
->trace_buffer
.data
->ftrace_ignore_pid
,
6347 trace_ignore_this_task(pid_list
, current
));
6351 ftrace_pid_write(struct file
*filp
, const char __user
*ubuf
,
6352 size_t cnt
, loff_t
*ppos
)
6354 struct seq_file
*m
= filp
->private_data
;
6355 struct trace_array
*tr
= m
->private;
6356 struct trace_pid_list
*filtered_pids
= NULL
;
6357 struct trace_pid_list
*pid_list
;
6363 mutex_lock(&ftrace_lock
);
6365 filtered_pids
= rcu_dereference_protected(tr
->function_pids
,
6366 lockdep_is_held(&ftrace_lock
));
6368 ret
= trace_pid_write(filtered_pids
, &pid_list
, ubuf
, cnt
);
6372 rcu_assign_pointer(tr
->function_pids
, pid_list
);
6374 if (filtered_pids
) {
6375 synchronize_sched();
6376 trace_free_pid_list(filtered_pids
);
6377 } else if (pid_list
) {
6378 /* Register a probe to set whether to ignore the tracing of a task */
6379 register_trace_sched_switch(ftrace_filter_pid_sched_switch_probe
, tr
);
6383 * Ignoring of pids is done at task switch. But we have to
6384 * check for those tasks that are currently running.
6385 * Always do this in case a pid was appended or removed.
6387 on_each_cpu(ignore_task_cpu
, tr
, 1);
6389 ftrace_update_pid_func();
6390 ftrace_startup_all(0);
6392 mutex_unlock(&ftrace_lock
);
6401 ftrace_pid_release(struct inode
*inode
, struct file
*file
)
6403 struct trace_array
*tr
= inode
->i_private
;
6405 trace_array_put(tr
);
6407 return seq_release(inode
, file
);
6410 static const struct file_operations ftrace_pid_fops
= {
6411 .open
= ftrace_pid_open
,
6412 .write
= ftrace_pid_write
,
6414 .llseek
= tracing_lseek
,
6415 .release
= ftrace_pid_release
,
6418 void ftrace_init_tracefs(struct trace_array
*tr
, struct dentry
*d_tracer
)
6420 trace_create_file("set_ftrace_pid", 0644, d_tracer
,
6421 tr
, &ftrace_pid_fops
);
6424 void __init
ftrace_init_tracefs_toplevel(struct trace_array
*tr
,
6425 struct dentry
*d_tracer
)
6427 /* Only the top level directory has the dyn_tracefs and profile */
6428 WARN_ON(!(tr
->flags
& TRACE_ARRAY_FL_GLOBAL
));
6430 ftrace_init_dyn_tracefs(d_tracer
);
6431 ftrace_profile_tracefs(d_tracer
);
6435 * ftrace_kill - kill ftrace
6437 * This function should be used by panic code. It stops ftrace
6438 * but in a not so nice way. If you need to simply kill ftrace
6439 * from a non-atomic section, use ftrace_kill.
6441 void ftrace_kill(void)
6443 ftrace_disabled
= 1;
6445 clear_ftrace_function();
6449 * Test if ftrace is dead or not.
6451 int ftrace_is_dead(void)
6453 return ftrace_disabled
;
6457 * register_ftrace_function - register a function for profiling
6458 * @ops - ops structure that holds the function for profiling.
6460 * Register a function to be called by all functions in the
6463 * Note: @ops->func and all the functions it calls must be labeled
6464 * with "notrace", otherwise it will go into a
6467 int register_ftrace_function(struct ftrace_ops
*ops
)
6471 ftrace_ops_init(ops
);
6473 mutex_lock(&ftrace_lock
);
6475 ret
= ftrace_startup(ops
, 0);
6477 mutex_unlock(&ftrace_lock
);
6481 EXPORT_SYMBOL_GPL(register_ftrace_function
);
6484 * unregister_ftrace_function - unregister a function for profiling.
6485 * @ops - ops structure that holds the function to unregister
6487 * Unregister a function that was added to be called by ftrace profiling.
6489 int unregister_ftrace_function(struct ftrace_ops
*ops
)
6493 mutex_lock(&ftrace_lock
);
6494 ret
= ftrace_shutdown(ops
, 0);
6495 mutex_unlock(&ftrace_lock
);
6499 EXPORT_SYMBOL_GPL(unregister_ftrace_function
);
6502 ftrace_enable_sysctl(struct ctl_table
*table
, int write
,
6503 void __user
*buffer
, size_t *lenp
,
6508 mutex_lock(&ftrace_lock
);
6510 if (unlikely(ftrace_disabled
))
6513 ret
= proc_dointvec(table
, write
, buffer
, lenp
, ppos
);
6515 if (ret
|| !write
|| (last_ftrace_enabled
== !!ftrace_enabled
))
6518 last_ftrace_enabled
= !!ftrace_enabled
;
6520 if (ftrace_enabled
) {
6522 /* we are starting ftrace again */
6523 if (rcu_dereference_protected(ftrace_ops_list
,
6524 lockdep_is_held(&ftrace_lock
)) != &ftrace_list_end
)
6525 update_ftrace_function();
6527 ftrace_startup_sysctl();
6530 /* stopping ftrace calls (just send to ftrace_stub) */
6531 ftrace_trace_function
= ftrace_stub
;
6533 ftrace_shutdown_sysctl();
6537 mutex_unlock(&ftrace_lock
);
6541 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
6543 static struct ftrace_ops graph_ops
= {
6544 .func
= ftrace_stub
,
6545 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
|
6546 FTRACE_OPS_FL_INITIALIZED
|
6549 #ifdef FTRACE_GRAPH_TRAMP_ADDR
6550 .trampoline
= FTRACE_GRAPH_TRAMP_ADDR
,
6551 /* trampoline_size is only needed for dynamically allocated tramps */
6553 ASSIGN_OPS_HASH(graph_ops
, &global_ops
.local_hash
)
6556 void ftrace_graph_sleep_time_control(bool enable
)
6558 fgraph_sleep_time
= enable
;
6561 void ftrace_graph_graph_time_control(bool enable
)
6563 fgraph_graph_time
= enable
;
6566 int ftrace_graph_entry_stub(struct ftrace_graph_ent
*trace
)
6571 /* The callbacks that hook a function */
6572 trace_func_graph_ret_t ftrace_graph_return
=
6573 (trace_func_graph_ret_t
)ftrace_stub
;
6574 trace_func_graph_ent_t ftrace_graph_entry
= ftrace_graph_entry_stub
;
6575 static trace_func_graph_ent_t __ftrace_graph_entry
= ftrace_graph_entry_stub
;
6577 /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
6578 static int alloc_retstack_tasklist(struct ftrace_ret_stack
**ret_stack_list
)
6582 int start
= 0, end
= FTRACE_RETSTACK_ALLOC_SIZE
;
6583 struct task_struct
*g
, *t
;
6585 for (i
= 0; i
< FTRACE_RETSTACK_ALLOC_SIZE
; i
++) {
6586 ret_stack_list
[i
] = kmalloc(FTRACE_RETFUNC_DEPTH
6587 * sizeof(struct ftrace_ret_stack
),
6589 if (!ret_stack_list
[i
]) {
6597 read_lock(&tasklist_lock
);
6598 do_each_thread(g
, t
) {
6604 if (t
->ret_stack
== NULL
) {
6605 atomic_set(&t
->tracing_graph_pause
, 0);
6606 atomic_set(&t
->trace_overrun
, 0);
6607 t
->curr_ret_stack
= -1;
6608 /* Make sure the tasks see the -1 first: */
6610 t
->ret_stack
= ret_stack_list
[start
++];
6612 } while_each_thread(g
, t
);
6615 read_unlock(&tasklist_lock
);
6617 for (i
= start
; i
< end
; i
++)
6618 kfree(ret_stack_list
[i
]);
6623 ftrace_graph_probe_sched_switch(void *ignore
, bool preempt
,
6624 struct task_struct
*prev
, struct task_struct
*next
)
6626 unsigned long long timestamp
;
6630 * Does the user want to count the time a function was asleep.
6631 * If so, do not update the time stamps.
6633 if (fgraph_sleep_time
)
6636 timestamp
= trace_clock_local();
6638 prev
->ftrace_timestamp
= timestamp
;
6640 /* only process tasks that we timestamped */
6641 if (!next
->ftrace_timestamp
)
6645 * Update all the counters in next to make up for the
6646 * time next was sleeping.
6648 timestamp
-= next
->ftrace_timestamp
;
6650 for (index
= next
->curr_ret_stack
; index
>= 0; index
--)
6651 next
->ret_stack
[index
].calltime
+= timestamp
;
6654 /* Allocate a return stack for each task */
6655 static int start_graph_tracing(void)
6657 struct ftrace_ret_stack
**ret_stack_list
;
6660 ret_stack_list
= kmalloc(FTRACE_RETSTACK_ALLOC_SIZE
*
6661 sizeof(struct ftrace_ret_stack
*),
6664 if (!ret_stack_list
)
6667 /* The cpu_boot init_task->ret_stack will never be freed */
6668 for_each_online_cpu(cpu
) {
6669 if (!idle_task(cpu
)->ret_stack
)
6670 ftrace_graph_init_idle_task(idle_task(cpu
), cpu
);
6674 ret
= alloc_retstack_tasklist(ret_stack_list
);
6675 } while (ret
== -EAGAIN
);
6678 ret
= register_trace_sched_switch(ftrace_graph_probe_sched_switch
, NULL
);
6680 pr_info("ftrace_graph: Couldn't activate tracepoint"
6681 " probe to kernel_sched_switch\n");
6684 kfree(ret_stack_list
);
6689 * Hibernation protection.
6690 * The state of the current task is too much unstable during
6691 * suspend/restore to disk. We want to protect against that.
6694 ftrace_suspend_notifier_call(struct notifier_block
*bl
, unsigned long state
,
6698 case PM_HIBERNATION_PREPARE
:
6699 pause_graph_tracing();
6702 case PM_POST_HIBERNATION
:
6703 unpause_graph_tracing();
6709 static int ftrace_graph_entry_test(struct ftrace_graph_ent
*trace
)
6711 if (!ftrace_ops_test(&global_ops
, trace
->func
, NULL
))
6713 return __ftrace_graph_entry(trace
);
6717 * The function graph tracer should only trace the functions defined
6718 * by set_ftrace_filter and set_ftrace_notrace. If another function
6719 * tracer ops is registered, the graph tracer requires testing the
6720 * function against the global ops, and not just trace any function
6721 * that any ftrace_ops registered.
6723 static void update_function_graph_func(void)
6725 struct ftrace_ops
*op
;
6726 bool do_test
= false;
6729 * The graph and global ops share the same set of functions
6730 * to test. If any other ops is on the list, then
6731 * the graph tracing needs to test if its the function
6734 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
6735 if (op
!= &global_ops
&& op
!= &graph_ops
&&
6736 op
!= &ftrace_list_end
) {
6738 /* in double loop, break out with goto */
6741 } while_for_each_ftrace_op(op
);
6744 ftrace_graph_entry
= ftrace_graph_entry_test
;
6746 ftrace_graph_entry
= __ftrace_graph_entry
;
6749 static struct notifier_block ftrace_suspend_notifier
= {
6750 .notifier_call
= ftrace_suspend_notifier_call
,
6753 int register_ftrace_graph(trace_func_graph_ret_t retfunc
,
6754 trace_func_graph_ent_t entryfunc
)
6758 mutex_lock(&ftrace_lock
);
6760 /* we currently allow only one tracer registered at a time */
6761 if (ftrace_graph_active
) {
6766 register_pm_notifier(&ftrace_suspend_notifier
);
6768 ftrace_graph_active
++;
6769 ret
= start_graph_tracing();
6771 ftrace_graph_active
--;
6775 ftrace_graph_return
= retfunc
;
6778 * Update the indirect function to the entryfunc, and the
6779 * function that gets called to the entry_test first. Then
6780 * call the update fgraph entry function to determine if
6781 * the entryfunc should be called directly or not.
6783 __ftrace_graph_entry
= entryfunc
;
6784 ftrace_graph_entry
= ftrace_graph_entry_test
;
6785 update_function_graph_func();
6787 ret
= ftrace_startup(&graph_ops
, FTRACE_START_FUNC_RET
);
6789 mutex_unlock(&ftrace_lock
);
6793 void unregister_ftrace_graph(void)
6795 mutex_lock(&ftrace_lock
);
6797 if (unlikely(!ftrace_graph_active
))
6800 ftrace_graph_active
--;
6801 ftrace_graph_return
= (trace_func_graph_ret_t
)ftrace_stub
;
6802 ftrace_graph_entry
= ftrace_graph_entry_stub
;
6803 __ftrace_graph_entry
= ftrace_graph_entry_stub
;
6804 ftrace_shutdown(&graph_ops
, FTRACE_STOP_FUNC_RET
);
6805 unregister_pm_notifier(&ftrace_suspend_notifier
);
6806 unregister_trace_sched_switch(ftrace_graph_probe_sched_switch
, NULL
);
6809 mutex_unlock(&ftrace_lock
);
6812 static DEFINE_PER_CPU(struct ftrace_ret_stack
*, idle_ret_stack
);
6815 graph_init_task(struct task_struct
*t
, struct ftrace_ret_stack
*ret_stack
)
6817 atomic_set(&t
->tracing_graph_pause
, 0);
6818 atomic_set(&t
->trace_overrun
, 0);
6819 t
->ftrace_timestamp
= 0;
6820 /* make curr_ret_stack visible before we add the ret_stack */
6822 t
->ret_stack
= ret_stack
;
6826 * Allocate a return stack for the idle task. May be the first
6827 * time through, or it may be done by CPU hotplug online.
6829 void ftrace_graph_init_idle_task(struct task_struct
*t
, int cpu
)
6831 t
->curr_ret_stack
= -1;
6833 * The idle task has no parent, it either has its own
6834 * stack or no stack at all.
6837 WARN_ON(t
->ret_stack
!= per_cpu(idle_ret_stack
, cpu
));
6839 if (ftrace_graph_active
) {
6840 struct ftrace_ret_stack
*ret_stack
;
6842 ret_stack
= per_cpu(idle_ret_stack
, cpu
);
6844 ret_stack
= kmalloc(FTRACE_RETFUNC_DEPTH
6845 * sizeof(struct ftrace_ret_stack
),
6849 per_cpu(idle_ret_stack
, cpu
) = ret_stack
;
6851 graph_init_task(t
, ret_stack
);
6855 /* Allocate a return stack for newly created task */
6856 void ftrace_graph_init_task(struct task_struct
*t
)
6858 /* Make sure we do not use the parent ret_stack */
6859 t
->ret_stack
= NULL
;
6860 t
->curr_ret_stack
= -1;
6862 if (ftrace_graph_active
) {
6863 struct ftrace_ret_stack
*ret_stack
;
6865 ret_stack
= kmalloc(FTRACE_RETFUNC_DEPTH
6866 * sizeof(struct ftrace_ret_stack
),
6870 graph_init_task(t
, ret_stack
);
6874 void ftrace_graph_exit_task(struct task_struct
*t
)
6876 struct ftrace_ret_stack
*ret_stack
= t
->ret_stack
;
6878 t
->ret_stack
= NULL
;
6879 /* NULL must become visible to IRQs before we free it: */