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1 /* SPDX-License-Identifier: GPL-2.0 */
2
3 #ifndef _LINUX_KERNEL_TRACE_H
4 #define _LINUX_KERNEL_TRACE_H
5
6 #include <linux/fs.h>
7 #include <linux/atomic.h>
8 #include <linux/sched.h>
9 #include <linux/clocksource.h>
10 #include <linux/ring_buffer.h>
11 #include <linux/mmiotrace.h>
12 #include <linux/tracepoint.h>
13 #include <linux/ftrace.h>
14 #include <linux/hw_breakpoint.h>
15 #include <linux/trace_seq.h>
16 #include <linux/trace_events.h>
17 #include <linux/compiler.h>
18 #include <linux/trace_seq.h>
19 #include <linux/glob.h>
20
21 #ifdef CONFIG_FTRACE_SYSCALLS
22 #include <asm/unistd.h> /* For NR_SYSCALLS */
23 #include <asm/syscall.h> /* some archs define it here */
24 #endif
25
26 enum trace_type {
27 __TRACE_FIRST_TYPE = 0,
28
29 TRACE_FN,
30 TRACE_CTX,
31 TRACE_WAKE,
32 TRACE_STACK,
33 TRACE_PRINT,
34 TRACE_BPRINT,
35 TRACE_MMIO_RW,
36 TRACE_MMIO_MAP,
37 TRACE_BRANCH,
38 TRACE_GRAPH_RET,
39 TRACE_GRAPH_ENT,
40 TRACE_USER_STACK,
41 TRACE_BLK,
42 TRACE_BPUTS,
43 TRACE_HWLAT,
44 TRACE_RAW_DATA,
45
46 __TRACE_LAST_TYPE,
47 };
48
49
50 #undef __field
51 #define __field(type, item) type item;
52
53 #undef __field_struct
54 #define __field_struct(type, item) __field(type, item)
55
56 #undef __field_desc
57 #define __field_desc(type, container, item)
58
59 #undef __array
60 #define __array(type, item, size) type item[size];
61
62 #undef __array_desc
63 #define __array_desc(type, container, item, size)
64
65 #undef __dynamic_array
66 #define __dynamic_array(type, item) type item[];
67
68 #undef F_STRUCT
69 #define F_STRUCT(args...) args
70
71 #undef FTRACE_ENTRY
72 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print, filter) \
73 struct struct_name { \
74 struct trace_entry ent; \
75 tstruct \
76 }
77
78 #undef FTRACE_ENTRY_DUP
79 #define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk, filter)
80
81 #undef FTRACE_ENTRY_REG
82 #define FTRACE_ENTRY_REG(name, struct_name, id, tstruct, print, \
83 filter, regfn) \
84 FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print), \
85 filter)
86
87 #undef FTRACE_ENTRY_PACKED
88 #define FTRACE_ENTRY_PACKED(name, struct_name, id, tstruct, print, \
89 filter) \
90 FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print), \
91 filter) __packed
92
93 #include "trace_entries.h"
94
95 /*
96 * syscalls are special, and need special handling, this is why
97 * they are not included in trace_entries.h
98 */
99 struct syscall_trace_enter {
100 struct trace_entry ent;
101 int nr;
102 unsigned long args[];
103 };
104
105 struct syscall_trace_exit {
106 struct trace_entry ent;
107 int nr;
108 long ret;
109 };
110
111 struct kprobe_trace_entry_head {
112 struct trace_entry ent;
113 unsigned long ip;
114 };
115
116 struct kretprobe_trace_entry_head {
117 struct trace_entry ent;
118 unsigned long func;
119 unsigned long ret_ip;
120 };
121
122 /*
123 * trace_flag_type is an enumeration that holds different
124 * states when a trace occurs. These are:
125 * IRQS_OFF - interrupts were disabled
126 * IRQS_NOSUPPORT - arch does not support irqs_disabled_flags
127 * NEED_RESCHED - reschedule is requested
128 * HARDIRQ - inside an interrupt handler
129 * SOFTIRQ - inside a softirq handler
130 */
131 enum trace_flag_type {
132 TRACE_FLAG_IRQS_OFF = 0x01,
133 TRACE_FLAG_IRQS_NOSUPPORT = 0x02,
134 TRACE_FLAG_NEED_RESCHED = 0x04,
135 TRACE_FLAG_HARDIRQ = 0x08,
136 TRACE_FLAG_SOFTIRQ = 0x10,
137 TRACE_FLAG_PREEMPT_RESCHED = 0x20,
138 TRACE_FLAG_NMI = 0x40,
139 };
140
141 #define TRACE_BUF_SIZE 1024
142
143 struct trace_array;
144
145 /*
146 * The CPU trace array - it consists of thousands of trace entries
147 * plus some other descriptor data: (for example which task started
148 * the trace, etc.)
149 */
150 struct trace_array_cpu {
151 atomic_t disabled;
152 void *buffer_page; /* ring buffer spare */
153
154 unsigned long entries;
155 unsigned long saved_latency;
156 unsigned long critical_start;
157 unsigned long critical_end;
158 unsigned long critical_sequence;
159 unsigned long nice;
160 unsigned long policy;
161 unsigned long rt_priority;
162 unsigned long skipped_entries;
163 u64 preempt_timestamp;
164 pid_t pid;
165 kuid_t uid;
166 char comm[TASK_COMM_LEN];
167
168 bool ignore_pid;
169 #ifdef CONFIG_FUNCTION_TRACER
170 bool ftrace_ignore_pid;
171 #endif
172 };
173
174 struct tracer;
175 struct trace_option_dentry;
176
177 struct trace_buffer {
178 struct trace_array *tr;
179 struct ring_buffer *buffer;
180 struct trace_array_cpu __percpu *data;
181 u64 time_start;
182 int cpu;
183 };
184
185 #define TRACE_FLAGS_MAX_SIZE 32
186
187 struct trace_options {
188 struct tracer *tracer;
189 struct trace_option_dentry *topts;
190 };
191
192 struct trace_pid_list {
193 int pid_max;
194 unsigned long *pids;
195 };
196
197 /*
198 * The trace array - an array of per-CPU trace arrays. This is the
199 * highest level data structure that individual tracers deal with.
200 * They have on/off state as well:
201 */
202 struct trace_array {
203 struct list_head list;
204 char *name;
205 struct trace_buffer trace_buffer;
206 #ifdef CONFIG_TRACER_MAX_TRACE
207 /*
208 * The max_buffer is used to snapshot the trace when a maximum
209 * latency is reached, or when the user initiates a snapshot.
210 * Some tracers will use this to store a maximum trace while
211 * it continues examining live traces.
212 *
213 * The buffers for the max_buffer are set up the same as the trace_buffer
214 * When a snapshot is taken, the buffer of the max_buffer is swapped
215 * with the buffer of the trace_buffer and the buffers are reset for
216 * the trace_buffer so the tracing can continue.
217 */
218 struct trace_buffer max_buffer;
219 bool allocated_snapshot;
220 #endif
221 #if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)
222 unsigned long max_latency;
223 #endif
224 struct trace_pid_list __rcu *filtered_pids;
225 /*
226 * max_lock is used to protect the swapping of buffers
227 * when taking a max snapshot. The buffers themselves are
228 * protected by per_cpu spinlocks. But the action of the swap
229 * needs its own lock.
230 *
231 * This is defined as a arch_spinlock_t in order to help
232 * with performance when lockdep debugging is enabled.
233 *
234 * It is also used in other places outside the update_max_tr
235 * so it needs to be defined outside of the
236 * CONFIG_TRACER_MAX_TRACE.
237 */
238 arch_spinlock_t max_lock;
239 int buffer_disabled;
240 #ifdef CONFIG_FTRACE_SYSCALLS
241 int sys_refcount_enter;
242 int sys_refcount_exit;
243 struct trace_event_file __rcu *enter_syscall_files[NR_syscalls];
244 struct trace_event_file __rcu *exit_syscall_files[NR_syscalls];
245 #endif
246 int stop_count;
247 int clock_id;
248 int nr_topts;
249 bool clear_trace;
250 struct tracer *current_trace;
251 unsigned int trace_flags;
252 unsigned char trace_flags_index[TRACE_FLAGS_MAX_SIZE];
253 unsigned int flags;
254 raw_spinlock_t start_lock;
255 struct dentry *dir;
256 struct dentry *options;
257 struct dentry *percpu_dir;
258 struct dentry *event_dir;
259 struct trace_options *topts;
260 struct list_head systems;
261 struct list_head events;
262 cpumask_var_t tracing_cpumask; /* only trace on set CPUs */
263 int ref;
264 #ifdef CONFIG_FUNCTION_TRACER
265 struct ftrace_ops *ops;
266 struct trace_pid_list __rcu *function_pids;
267 #ifdef CONFIG_DYNAMIC_FTRACE
268 /* All of these are protected by the ftrace_lock */
269 struct list_head func_probes;
270 struct list_head mod_trace;
271 struct list_head mod_notrace;
272 #endif
273 /* function tracing enabled */
274 int function_enabled;
275 #endif
276 };
277
278 enum {
279 TRACE_ARRAY_FL_GLOBAL = (1 << 0)
280 };
281
282 extern struct list_head ftrace_trace_arrays;
283
284 extern struct mutex trace_types_lock;
285
286 extern int trace_array_get(struct trace_array *tr);
287 extern void trace_array_put(struct trace_array *tr);
288
289 /*
290 * The global tracer (top) should be the first trace array added,
291 * but we check the flag anyway.
292 */
293 static inline struct trace_array *top_trace_array(void)
294 {
295 struct trace_array *tr;
296
297 if (list_empty(&ftrace_trace_arrays))
298 return NULL;
299
300 tr = list_entry(ftrace_trace_arrays.prev,
301 typeof(*tr), list);
302 WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
303 return tr;
304 }
305
306 #define FTRACE_CMP_TYPE(var, type) \
307 __builtin_types_compatible_p(typeof(var), type *)
308
309 #undef IF_ASSIGN
310 #define IF_ASSIGN(var, entry, etype, id) \
311 if (FTRACE_CMP_TYPE(var, etype)) { \
312 var = (typeof(var))(entry); \
313 WARN_ON(id && (entry)->type != id); \
314 break; \
315 }
316
317 /* Will cause compile errors if type is not found. */
318 extern void __ftrace_bad_type(void);
319
320 /*
321 * The trace_assign_type is a verifier that the entry type is
322 * the same as the type being assigned. To add new types simply
323 * add a line with the following format:
324 *
325 * IF_ASSIGN(var, ent, type, id);
326 *
327 * Where "type" is the trace type that includes the trace_entry
328 * as the "ent" item. And "id" is the trace identifier that is
329 * used in the trace_type enum.
330 *
331 * If the type can have more than one id, then use zero.
332 */
333 #define trace_assign_type(var, ent) \
334 do { \
335 IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN); \
336 IF_ASSIGN(var, ent, struct ctx_switch_entry, 0); \
337 IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK); \
338 IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
339 IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT); \
340 IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT); \
341 IF_ASSIGN(var, ent, struct bputs_entry, TRACE_BPUTS); \
342 IF_ASSIGN(var, ent, struct hwlat_entry, TRACE_HWLAT); \
343 IF_ASSIGN(var, ent, struct raw_data_entry, TRACE_RAW_DATA);\
344 IF_ASSIGN(var, ent, struct trace_mmiotrace_rw, \
345 TRACE_MMIO_RW); \
346 IF_ASSIGN(var, ent, struct trace_mmiotrace_map, \
347 TRACE_MMIO_MAP); \
348 IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
349 IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry, \
350 TRACE_GRAPH_ENT); \
351 IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry, \
352 TRACE_GRAPH_RET); \
353 __ftrace_bad_type(); \
354 } while (0)
355
356 /*
357 * An option specific to a tracer. This is a boolean value.
358 * The bit is the bit index that sets its value on the
359 * flags value in struct tracer_flags.
360 */
361 struct tracer_opt {
362 const char *name; /* Will appear on the trace_options file */
363 u32 bit; /* Mask assigned in val field in tracer_flags */
364 };
365
366 /*
367 * The set of specific options for a tracer. Your tracer
368 * have to set the initial value of the flags val.
369 */
370 struct tracer_flags {
371 u32 val;
372 struct tracer_opt *opts;
373 struct tracer *trace;
374 };
375
376 /* Makes more easy to define a tracer opt */
377 #define TRACER_OPT(s, b) .name = #s, .bit = b
378
379
380 struct trace_option_dentry {
381 struct tracer_opt *opt;
382 struct tracer_flags *flags;
383 struct trace_array *tr;
384 struct dentry *entry;
385 };
386
387 /**
388 * struct tracer - a specific tracer and its callbacks to interact with tracefs
389 * @name: the name chosen to select it on the available_tracers file
390 * @init: called when one switches to this tracer (echo name > current_tracer)
391 * @reset: called when one switches to another tracer
392 * @start: called when tracing is unpaused (echo 1 > tracing_on)
393 * @stop: called when tracing is paused (echo 0 > tracing_on)
394 * @update_thresh: called when tracing_thresh is updated
395 * @open: called when the trace file is opened
396 * @pipe_open: called when the trace_pipe file is opened
397 * @close: called when the trace file is released
398 * @pipe_close: called when the trace_pipe file is released
399 * @read: override the default read callback on trace_pipe
400 * @splice_read: override the default splice_read callback on trace_pipe
401 * @selftest: selftest to run on boot (see trace_selftest.c)
402 * @print_headers: override the first lines that describe your columns
403 * @print_line: callback that prints a trace
404 * @set_flag: signals one of your private flags changed (trace_options file)
405 * @flags: your private flags
406 */
407 struct tracer {
408 const char *name;
409 int (*init)(struct trace_array *tr);
410 void (*reset)(struct trace_array *tr);
411 void (*start)(struct trace_array *tr);
412 void (*stop)(struct trace_array *tr);
413 int (*update_thresh)(struct trace_array *tr);
414 void (*open)(struct trace_iterator *iter);
415 void (*pipe_open)(struct trace_iterator *iter);
416 void (*close)(struct trace_iterator *iter);
417 void (*pipe_close)(struct trace_iterator *iter);
418 ssize_t (*read)(struct trace_iterator *iter,
419 struct file *filp, char __user *ubuf,
420 size_t cnt, loff_t *ppos);
421 ssize_t (*splice_read)(struct trace_iterator *iter,
422 struct file *filp,
423 loff_t *ppos,
424 struct pipe_inode_info *pipe,
425 size_t len,
426 unsigned int flags);
427 #ifdef CONFIG_FTRACE_STARTUP_TEST
428 int (*selftest)(struct tracer *trace,
429 struct trace_array *tr);
430 #endif
431 void (*print_header)(struct seq_file *m);
432 enum print_line_t (*print_line)(struct trace_iterator *iter);
433 /* If you handled the flag setting, return 0 */
434 int (*set_flag)(struct trace_array *tr,
435 u32 old_flags, u32 bit, int set);
436 /* Return 0 if OK with change, else return non-zero */
437 int (*flag_changed)(struct trace_array *tr,
438 u32 mask, int set);
439 struct tracer *next;
440 struct tracer_flags *flags;
441 int enabled;
442 int ref;
443 bool print_max;
444 bool allow_instances;
445 #ifdef CONFIG_TRACER_MAX_TRACE
446 bool use_max_tr;
447 #endif
448 /* True if tracer cannot be enabled in kernel param */
449 bool noboot;
450 };
451
452
453 /* Only current can touch trace_recursion */
454
455 /*
456 * For function tracing recursion:
457 * The order of these bits are important.
458 *
459 * When function tracing occurs, the following steps are made:
460 * If arch does not support a ftrace feature:
461 * call internal function (uses INTERNAL bits) which calls...
462 * If callback is registered to the "global" list, the list
463 * function is called and recursion checks the GLOBAL bits.
464 * then this function calls...
465 * The function callback, which can use the FTRACE bits to
466 * check for recursion.
467 *
468 * Now if the arch does not suppport a feature, and it calls
469 * the global list function which calls the ftrace callback
470 * all three of these steps will do a recursion protection.
471 * There's no reason to do one if the previous caller already
472 * did. The recursion that we are protecting against will
473 * go through the same steps again.
474 *
475 * To prevent the multiple recursion checks, if a recursion
476 * bit is set that is higher than the MAX bit of the current
477 * check, then we know that the check was made by the previous
478 * caller, and we can skip the current check.
479 */
480 enum {
481 TRACE_BUFFER_BIT,
482 TRACE_BUFFER_NMI_BIT,
483 TRACE_BUFFER_IRQ_BIT,
484 TRACE_BUFFER_SIRQ_BIT,
485
486 /* Start of function recursion bits */
487 TRACE_FTRACE_BIT,
488 TRACE_FTRACE_NMI_BIT,
489 TRACE_FTRACE_IRQ_BIT,
490 TRACE_FTRACE_SIRQ_BIT,
491
492 /* INTERNAL_BITs must be greater than FTRACE_BITs */
493 TRACE_INTERNAL_BIT,
494 TRACE_INTERNAL_NMI_BIT,
495 TRACE_INTERNAL_IRQ_BIT,
496 TRACE_INTERNAL_SIRQ_BIT,
497
498 TRACE_BRANCH_BIT,
499 /*
500 * Abuse of the trace_recursion.
501 * As we need a way to maintain state if we are tracing the function
502 * graph in irq because we want to trace a particular function that
503 * was called in irq context but we have irq tracing off. Since this
504 * can only be modified by current, we can reuse trace_recursion.
505 */
506 TRACE_IRQ_BIT,
507 };
508
509 #define trace_recursion_set(bit) do { (current)->trace_recursion |= (1<<(bit)); } while (0)
510 #define trace_recursion_clear(bit) do { (current)->trace_recursion &= ~(1<<(bit)); } while (0)
511 #define trace_recursion_test(bit) ((current)->trace_recursion & (1<<(bit)))
512
513 #define TRACE_CONTEXT_BITS 4
514
515 #define TRACE_FTRACE_START TRACE_FTRACE_BIT
516 #define TRACE_FTRACE_MAX ((1 << (TRACE_FTRACE_START + TRACE_CONTEXT_BITS)) - 1)
517
518 #define TRACE_LIST_START TRACE_INTERNAL_BIT
519 #define TRACE_LIST_MAX ((1 << (TRACE_LIST_START + TRACE_CONTEXT_BITS)) - 1)
520
521 #define TRACE_CONTEXT_MASK TRACE_LIST_MAX
522
523 static __always_inline int trace_get_context_bit(void)
524 {
525 int bit;
526
527 if (in_interrupt()) {
528 if (in_nmi())
529 bit = 0;
530
531 else if (in_irq())
532 bit = 1;
533 else
534 bit = 2;
535 } else
536 bit = 3;
537
538 return bit;
539 }
540
541 static __always_inline int trace_test_and_set_recursion(int start, int max)
542 {
543 unsigned int val = current->trace_recursion;
544 int bit;
545
546 /* A previous recursion check was made */
547 if ((val & TRACE_CONTEXT_MASK) > max)
548 return 0;
549
550 bit = trace_get_context_bit() + start;
551 if (unlikely(val & (1 << bit)))
552 return -1;
553
554 val |= 1 << bit;
555 current->trace_recursion = val;
556 barrier();
557
558 return bit;
559 }
560
561 static __always_inline void trace_clear_recursion(int bit)
562 {
563 unsigned int val = current->trace_recursion;
564
565 if (!bit)
566 return;
567
568 bit = 1 << bit;
569 val &= ~bit;
570
571 barrier();
572 current->trace_recursion = val;
573 }
574
575 static inline struct ring_buffer_iter *
576 trace_buffer_iter(struct trace_iterator *iter, int cpu)
577 {
578 if (iter->buffer_iter && iter->buffer_iter[cpu])
579 return iter->buffer_iter[cpu];
580 return NULL;
581 }
582
583 int tracer_init(struct tracer *t, struct trace_array *tr);
584 int tracing_is_enabled(void);
585 void tracing_reset(struct trace_buffer *buf, int cpu);
586 void tracing_reset_online_cpus(struct trace_buffer *buf);
587 void tracing_reset_current(int cpu);
588 void tracing_reset_all_online_cpus(void);
589 int tracing_open_generic(struct inode *inode, struct file *filp);
590 bool tracing_is_disabled(void);
591 int tracer_tracing_is_on(struct trace_array *tr);
592 void tracer_tracing_on(struct trace_array *tr);
593 void tracer_tracing_off(struct trace_array *tr);
594 struct dentry *trace_create_file(const char *name,
595 umode_t mode,
596 struct dentry *parent,
597 void *data,
598 const struct file_operations *fops);
599
600 struct dentry *tracing_init_dentry(void);
601
602 struct ring_buffer_event;
603
604 struct ring_buffer_event *
605 trace_buffer_lock_reserve(struct ring_buffer *buffer,
606 int type,
607 unsigned long len,
608 unsigned long flags,
609 int pc);
610
611 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
612 struct trace_array_cpu *data);
613
614 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
615 int *ent_cpu, u64 *ent_ts);
616
617 void trace_buffer_unlock_commit_nostack(struct ring_buffer *buffer,
618 struct ring_buffer_event *event);
619
620 int trace_empty(struct trace_iterator *iter);
621
622 void *trace_find_next_entry_inc(struct trace_iterator *iter);
623
624 void trace_init_global_iter(struct trace_iterator *iter);
625
626 void tracing_iter_reset(struct trace_iterator *iter, int cpu);
627
628 void trace_function(struct trace_array *tr,
629 unsigned long ip,
630 unsigned long parent_ip,
631 unsigned long flags, int pc);
632 void trace_graph_function(struct trace_array *tr,
633 unsigned long ip,
634 unsigned long parent_ip,
635 unsigned long flags, int pc);
636 void trace_latency_header(struct seq_file *m);
637 void trace_default_header(struct seq_file *m);
638 void print_trace_header(struct seq_file *m, struct trace_iterator *iter);
639 int trace_empty(struct trace_iterator *iter);
640
641 void trace_graph_return(struct ftrace_graph_ret *trace);
642 int trace_graph_entry(struct ftrace_graph_ent *trace);
643 void set_graph_array(struct trace_array *tr);
644
645 void tracing_start_cmdline_record(void);
646 void tracing_stop_cmdline_record(void);
647 void tracing_start_tgid_record(void);
648 void tracing_stop_tgid_record(void);
649
650 int register_tracer(struct tracer *type);
651 int is_tracing_stopped(void);
652
653 loff_t tracing_lseek(struct file *file, loff_t offset, int whence);
654
655 extern cpumask_var_t __read_mostly tracing_buffer_mask;
656
657 #define for_each_tracing_cpu(cpu) \
658 for_each_cpu(cpu, tracing_buffer_mask)
659
660 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
661
662 extern unsigned long tracing_thresh;
663
664 /* PID filtering */
665
666 extern int pid_max;
667
668 bool trace_find_filtered_pid(struct trace_pid_list *filtered_pids,
669 pid_t search_pid);
670 bool trace_ignore_this_task(struct trace_pid_list *filtered_pids,
671 struct task_struct *task);
672 void trace_filter_add_remove_task(struct trace_pid_list *pid_list,
673 struct task_struct *self,
674 struct task_struct *task);
675 void *trace_pid_next(struct trace_pid_list *pid_list, void *v, loff_t *pos);
676 void *trace_pid_start(struct trace_pid_list *pid_list, loff_t *pos);
677 int trace_pid_show(struct seq_file *m, void *v);
678 void trace_free_pid_list(struct trace_pid_list *pid_list);
679 int trace_pid_write(struct trace_pid_list *filtered_pids,
680 struct trace_pid_list **new_pid_list,
681 const char __user *ubuf, size_t cnt);
682
683 #ifdef CONFIG_TRACER_MAX_TRACE
684 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
685 void update_max_tr_single(struct trace_array *tr,
686 struct task_struct *tsk, int cpu);
687 #endif /* CONFIG_TRACER_MAX_TRACE */
688
689 #ifdef CONFIG_STACKTRACE
690 void ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags,
691 int pc);
692
693 void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
694 int pc);
695 #else
696 static inline void ftrace_trace_userstack(struct ring_buffer *buffer,
697 unsigned long flags, int pc)
698 {
699 }
700
701 static inline void __trace_stack(struct trace_array *tr, unsigned long flags,
702 int skip, int pc)
703 {
704 }
705 #endif /* CONFIG_STACKTRACE */
706
707 extern u64 ftrace_now(int cpu);
708
709 extern void trace_find_cmdline(int pid, char comm[]);
710 extern int trace_find_tgid(int pid);
711 extern void trace_event_follow_fork(struct trace_array *tr, bool enable);
712
713 #ifdef CONFIG_DYNAMIC_FTRACE
714 extern unsigned long ftrace_update_tot_cnt;
715 void ftrace_init_trace_array(struct trace_array *tr);
716 #else
717 static inline void ftrace_init_trace_array(struct trace_array *tr) { }
718 #endif
719 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
720 extern int DYN_FTRACE_TEST_NAME(void);
721 #define DYN_FTRACE_TEST_NAME2 trace_selftest_dynamic_test_func2
722 extern int DYN_FTRACE_TEST_NAME2(void);
723
724 extern bool ring_buffer_expanded;
725 extern bool tracing_selftest_disabled;
726
727 #ifdef CONFIG_FTRACE_STARTUP_TEST
728 extern int trace_selftest_startup_function(struct tracer *trace,
729 struct trace_array *tr);
730 extern int trace_selftest_startup_function_graph(struct tracer *trace,
731 struct trace_array *tr);
732 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
733 struct trace_array *tr);
734 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
735 struct trace_array *tr);
736 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
737 struct trace_array *tr);
738 extern int trace_selftest_startup_wakeup(struct tracer *trace,
739 struct trace_array *tr);
740 extern int trace_selftest_startup_nop(struct tracer *trace,
741 struct trace_array *tr);
742 extern int trace_selftest_startup_sched_switch(struct tracer *trace,
743 struct trace_array *tr);
744 extern int trace_selftest_startup_branch(struct tracer *trace,
745 struct trace_array *tr);
746 /*
747 * Tracer data references selftest functions that only occur
748 * on boot up. These can be __init functions. Thus, when selftests
749 * are enabled, then the tracers need to reference __init functions.
750 */
751 #define __tracer_data __refdata
752 #else
753 /* Tracers are seldom changed. Optimize when selftests are disabled. */
754 #define __tracer_data __read_mostly
755 #endif /* CONFIG_FTRACE_STARTUP_TEST */
756
757 extern void *head_page(struct trace_array_cpu *data);
758 extern unsigned long long ns2usecs(u64 nsec);
759 extern int
760 trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
761 extern int
762 trace_vprintk(unsigned long ip, const char *fmt, va_list args);
763 extern int
764 trace_array_vprintk(struct trace_array *tr,
765 unsigned long ip, const char *fmt, va_list args);
766 int trace_array_printk(struct trace_array *tr,
767 unsigned long ip, const char *fmt, ...);
768 int trace_array_printk_buf(struct ring_buffer *buffer,
769 unsigned long ip, const char *fmt, ...);
770 void trace_printk_seq(struct trace_seq *s);
771 enum print_line_t print_trace_line(struct trace_iterator *iter);
772
773 extern char trace_find_mark(unsigned long long duration);
774
775 struct ftrace_hash;
776
777 struct ftrace_mod_load {
778 struct list_head list;
779 char *func;
780 char *module;
781 int enable;
782 };
783
784 enum {
785 FTRACE_HASH_FL_MOD = (1 << 0),
786 };
787
788 struct ftrace_hash {
789 unsigned long size_bits;
790 struct hlist_head *buckets;
791 unsigned long count;
792 unsigned long flags;
793 struct rcu_head rcu;
794 };
795
796 struct ftrace_func_entry *
797 ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip);
798
799 static __always_inline bool ftrace_hash_empty(struct ftrace_hash *hash)
800 {
801 return !hash || !(hash->count || (hash->flags & FTRACE_HASH_FL_MOD));
802 }
803
804 /* Standard output formatting function used for function return traces */
805 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
806
807 /* Flag options */
808 #define TRACE_GRAPH_PRINT_OVERRUN 0x1
809 #define TRACE_GRAPH_PRINT_CPU 0x2
810 #define TRACE_GRAPH_PRINT_OVERHEAD 0x4
811 #define TRACE_GRAPH_PRINT_PROC 0x8
812 #define TRACE_GRAPH_PRINT_DURATION 0x10
813 #define TRACE_GRAPH_PRINT_ABS_TIME 0x20
814 #define TRACE_GRAPH_PRINT_IRQS 0x40
815 #define TRACE_GRAPH_PRINT_TAIL 0x80
816 #define TRACE_GRAPH_SLEEP_TIME 0x100
817 #define TRACE_GRAPH_GRAPH_TIME 0x200
818 #define TRACE_GRAPH_PRINT_FILL_SHIFT 28
819 #define TRACE_GRAPH_PRINT_FILL_MASK (0x3 << TRACE_GRAPH_PRINT_FILL_SHIFT)
820
821 extern void ftrace_graph_sleep_time_control(bool enable);
822 extern void ftrace_graph_graph_time_control(bool enable);
823
824 extern enum print_line_t
825 print_graph_function_flags(struct trace_iterator *iter, u32 flags);
826 extern void print_graph_headers_flags(struct seq_file *s, u32 flags);
827 extern void
828 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
829 extern void graph_trace_open(struct trace_iterator *iter);
830 extern void graph_trace_close(struct trace_iterator *iter);
831 extern int __trace_graph_entry(struct trace_array *tr,
832 struct ftrace_graph_ent *trace,
833 unsigned long flags, int pc);
834 extern void __trace_graph_return(struct trace_array *tr,
835 struct ftrace_graph_ret *trace,
836 unsigned long flags, int pc);
837
838 #ifdef CONFIG_DYNAMIC_FTRACE
839 extern struct ftrace_hash *ftrace_graph_hash;
840 extern struct ftrace_hash *ftrace_graph_notrace_hash;
841
842 static inline int ftrace_graph_addr(unsigned long addr)
843 {
844 int ret = 0;
845
846 preempt_disable_notrace();
847
848 if (ftrace_hash_empty(ftrace_graph_hash)) {
849 ret = 1;
850 goto out;
851 }
852
853 if (ftrace_lookup_ip(ftrace_graph_hash, addr)) {
854 /*
855 * If no irqs are to be traced, but a set_graph_function
856 * is set, and called by an interrupt handler, we still
857 * want to trace it.
858 */
859 if (in_irq())
860 trace_recursion_set(TRACE_IRQ_BIT);
861 else
862 trace_recursion_clear(TRACE_IRQ_BIT);
863 ret = 1;
864 }
865
866 out:
867 preempt_enable_notrace();
868 return ret;
869 }
870
871 static inline int ftrace_graph_notrace_addr(unsigned long addr)
872 {
873 int ret = 0;
874
875 preempt_disable_notrace();
876
877 if (ftrace_lookup_ip(ftrace_graph_notrace_hash, addr))
878 ret = 1;
879
880 preempt_enable_notrace();
881 return ret;
882 }
883 #else
884 static inline int ftrace_graph_addr(unsigned long addr)
885 {
886 return 1;
887 }
888
889 static inline int ftrace_graph_notrace_addr(unsigned long addr)
890 {
891 return 0;
892 }
893 #endif /* CONFIG_DYNAMIC_FTRACE */
894
895 extern unsigned int fgraph_max_depth;
896
897 static inline bool ftrace_graph_ignore_func(struct ftrace_graph_ent *trace)
898 {
899 /* trace it when it is-nested-in or is a function enabled. */
900 return !(trace->depth || ftrace_graph_addr(trace->func)) ||
901 (trace->depth < 0) ||
902 (fgraph_max_depth && trace->depth >= fgraph_max_depth);
903 }
904
905 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
906 static inline enum print_line_t
907 print_graph_function_flags(struct trace_iterator *iter, u32 flags)
908 {
909 return TRACE_TYPE_UNHANDLED;
910 }
911 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
912
913 extern struct list_head ftrace_pids;
914
915 #ifdef CONFIG_FUNCTION_TRACER
916 struct ftrace_func_command {
917 struct list_head list;
918 char *name;
919 int (*func)(struct trace_array *tr,
920 struct ftrace_hash *hash,
921 char *func, char *cmd,
922 char *params, int enable);
923 };
924 extern bool ftrace_filter_param __initdata;
925 static inline int ftrace_trace_task(struct trace_array *tr)
926 {
927 return !this_cpu_read(tr->trace_buffer.data->ftrace_ignore_pid);
928 }
929 extern int ftrace_is_dead(void);
930 int ftrace_create_function_files(struct trace_array *tr,
931 struct dentry *parent);
932 void ftrace_destroy_function_files(struct trace_array *tr);
933 void ftrace_init_global_array_ops(struct trace_array *tr);
934 void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func);
935 void ftrace_reset_array_ops(struct trace_array *tr);
936 int using_ftrace_ops_list_func(void);
937 void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer);
938 void ftrace_init_tracefs_toplevel(struct trace_array *tr,
939 struct dentry *d_tracer);
940 void ftrace_clear_pids(struct trace_array *tr);
941 int init_function_trace(void);
942 void ftrace_pid_follow_fork(struct trace_array *tr, bool enable);
943 #else
944 static inline int ftrace_trace_task(struct trace_array *tr)
945 {
946 return 1;
947 }
948 static inline int ftrace_is_dead(void) { return 0; }
949 static inline int
950 ftrace_create_function_files(struct trace_array *tr,
951 struct dentry *parent)
952 {
953 return 0;
954 }
955 static inline void ftrace_destroy_function_files(struct trace_array *tr) { }
956 static inline __init void
957 ftrace_init_global_array_ops(struct trace_array *tr) { }
958 static inline void ftrace_reset_array_ops(struct trace_array *tr) { }
959 static inline void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d) { }
960 static inline void ftrace_init_tracefs_toplevel(struct trace_array *tr, struct dentry *d) { }
961 static inline void ftrace_clear_pids(struct trace_array *tr) { }
962 static inline int init_function_trace(void) { return 0; }
963 static inline void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) { }
964 /* ftace_func_t type is not defined, use macro instead of static inline */
965 #define ftrace_init_array_ops(tr, func) do { } while (0)
966 #endif /* CONFIG_FUNCTION_TRACER */
967
968 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
969
970 struct ftrace_probe_ops {
971 void (*func)(unsigned long ip,
972 unsigned long parent_ip,
973 struct trace_array *tr,
974 struct ftrace_probe_ops *ops,
975 void *data);
976 int (*init)(struct ftrace_probe_ops *ops,
977 struct trace_array *tr,
978 unsigned long ip, void *init_data,
979 void **data);
980 void (*free)(struct ftrace_probe_ops *ops,
981 struct trace_array *tr,
982 unsigned long ip, void *data);
983 int (*print)(struct seq_file *m,
984 unsigned long ip,
985 struct ftrace_probe_ops *ops,
986 void *data);
987 };
988
989 struct ftrace_func_mapper;
990 typedef int (*ftrace_mapper_func)(void *data);
991
992 struct ftrace_func_mapper *allocate_ftrace_func_mapper(void);
993 void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
994 unsigned long ip);
995 int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
996 unsigned long ip, void *data);
997 void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
998 unsigned long ip);
999 void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
1000 ftrace_mapper_func free_func);
1001
1002 extern int
1003 register_ftrace_function_probe(char *glob, struct trace_array *tr,
1004 struct ftrace_probe_ops *ops, void *data);
1005 extern int
1006 unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
1007 struct ftrace_probe_ops *ops);
1008 extern void clear_ftrace_function_probes(struct trace_array *tr);
1009
1010 int register_ftrace_command(struct ftrace_func_command *cmd);
1011 int unregister_ftrace_command(struct ftrace_func_command *cmd);
1012
1013 void ftrace_create_filter_files(struct ftrace_ops *ops,
1014 struct dentry *parent);
1015 void ftrace_destroy_filter_files(struct ftrace_ops *ops);
1016 #else
1017 struct ftrace_func_command;
1018
1019 static inline __init int register_ftrace_command(struct ftrace_func_command *cmd)
1020 {
1021 return -EINVAL;
1022 }
1023 static inline __init int unregister_ftrace_command(char *cmd_name)
1024 {
1025 return -EINVAL;
1026 }
1027 static inline void clear_ftrace_function_probes(struct trace_array *tr)
1028 {
1029 }
1030
1031 /*
1032 * The ops parameter passed in is usually undefined.
1033 * This must be a macro.
1034 */
1035 #define ftrace_create_filter_files(ops, parent) do { } while (0)
1036 #define ftrace_destroy_filter_files(ops) do { } while (0)
1037 #endif /* CONFIG_FUNCTION_TRACER && CONFIG_DYNAMIC_FTRACE */
1038
1039 bool ftrace_event_is_function(struct trace_event_call *call);
1040
1041 /*
1042 * struct trace_parser - servers for reading the user input separated by spaces
1043 * @cont: set if the input is not complete - no final space char was found
1044 * @buffer: holds the parsed user input
1045 * @idx: user input length
1046 * @size: buffer size
1047 */
1048 struct trace_parser {
1049 bool cont;
1050 char *buffer;
1051 unsigned idx;
1052 unsigned size;
1053 };
1054
1055 static inline bool trace_parser_loaded(struct trace_parser *parser)
1056 {
1057 return (parser->idx != 0);
1058 }
1059
1060 static inline bool trace_parser_cont(struct trace_parser *parser)
1061 {
1062 return parser->cont;
1063 }
1064
1065 static inline void trace_parser_clear(struct trace_parser *parser)
1066 {
1067 parser->cont = false;
1068 parser->idx = 0;
1069 }
1070
1071 extern int trace_parser_get_init(struct trace_parser *parser, int size);
1072 extern void trace_parser_put(struct trace_parser *parser);
1073 extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
1074 size_t cnt, loff_t *ppos);
1075
1076 /*
1077 * Only create function graph options if function graph is configured.
1078 */
1079 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1080 # define FGRAPH_FLAGS \
1081 C(DISPLAY_GRAPH, "display-graph"),
1082 #else
1083 # define FGRAPH_FLAGS
1084 #endif
1085
1086 #ifdef CONFIG_BRANCH_TRACER
1087 # define BRANCH_FLAGS \
1088 C(BRANCH, "branch"),
1089 #else
1090 # define BRANCH_FLAGS
1091 #endif
1092
1093 #ifdef CONFIG_FUNCTION_TRACER
1094 # define FUNCTION_FLAGS \
1095 C(FUNCTION, "function-trace"), \
1096 C(FUNC_FORK, "function-fork"),
1097 # define FUNCTION_DEFAULT_FLAGS TRACE_ITER_FUNCTION
1098 #else
1099 # define FUNCTION_FLAGS
1100 # define FUNCTION_DEFAULT_FLAGS 0UL
1101 # define TRACE_ITER_FUNC_FORK 0UL
1102 #endif
1103
1104 #ifdef CONFIG_STACKTRACE
1105 # define STACK_FLAGS \
1106 C(STACKTRACE, "stacktrace"),
1107 #else
1108 # define STACK_FLAGS
1109 #endif
1110
1111 /*
1112 * trace_iterator_flags is an enumeration that defines bit
1113 * positions into trace_flags that controls the output.
1114 *
1115 * NOTE: These bits must match the trace_options array in
1116 * trace.c (this macro guarantees it).
1117 */
1118 #define TRACE_FLAGS \
1119 C(PRINT_PARENT, "print-parent"), \
1120 C(SYM_OFFSET, "sym-offset"), \
1121 C(SYM_ADDR, "sym-addr"), \
1122 C(VERBOSE, "verbose"), \
1123 C(RAW, "raw"), \
1124 C(HEX, "hex"), \
1125 C(BIN, "bin"), \
1126 C(BLOCK, "block"), \
1127 C(PRINTK, "trace_printk"), \
1128 C(ANNOTATE, "annotate"), \
1129 C(USERSTACKTRACE, "userstacktrace"), \
1130 C(SYM_USEROBJ, "sym-userobj"), \
1131 C(PRINTK_MSGONLY, "printk-msg-only"), \
1132 C(CONTEXT_INFO, "context-info"), /* Print pid/cpu/time */ \
1133 C(LATENCY_FMT, "latency-format"), \
1134 C(RECORD_CMD, "record-cmd"), \
1135 C(RECORD_TGID, "record-tgid"), \
1136 C(OVERWRITE, "overwrite"), \
1137 C(STOP_ON_FREE, "disable_on_free"), \
1138 C(IRQ_INFO, "irq-info"), \
1139 C(MARKERS, "markers"), \
1140 C(EVENT_FORK, "event-fork"), \
1141 FUNCTION_FLAGS \
1142 FGRAPH_FLAGS \
1143 STACK_FLAGS \
1144 BRANCH_FLAGS
1145
1146 /*
1147 * By defining C, we can make TRACE_FLAGS a list of bit names
1148 * that will define the bits for the flag masks.
1149 */
1150 #undef C
1151 #define C(a, b) TRACE_ITER_##a##_BIT
1152
1153 enum trace_iterator_bits {
1154 TRACE_FLAGS
1155 /* Make sure we don't go more than we have bits for */
1156 TRACE_ITER_LAST_BIT
1157 };
1158
1159 /*
1160 * By redefining C, we can make TRACE_FLAGS a list of masks that
1161 * use the bits as defined above.
1162 */
1163 #undef C
1164 #define C(a, b) TRACE_ITER_##a = (1 << TRACE_ITER_##a##_BIT)
1165
1166 enum trace_iterator_flags { TRACE_FLAGS };
1167
1168 /*
1169 * TRACE_ITER_SYM_MASK masks the options in trace_flags that
1170 * control the output of kernel symbols.
1171 */
1172 #define TRACE_ITER_SYM_MASK \
1173 (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
1174
1175 extern struct tracer nop_trace;
1176
1177 #ifdef CONFIG_BRANCH_TRACER
1178 extern int enable_branch_tracing(struct trace_array *tr);
1179 extern void disable_branch_tracing(void);
1180 static inline int trace_branch_enable(struct trace_array *tr)
1181 {
1182 if (tr->trace_flags & TRACE_ITER_BRANCH)
1183 return enable_branch_tracing(tr);
1184 return 0;
1185 }
1186 static inline void trace_branch_disable(void)
1187 {
1188 /* due to races, always disable */
1189 disable_branch_tracing();
1190 }
1191 #else
1192 static inline int trace_branch_enable(struct trace_array *tr)
1193 {
1194 return 0;
1195 }
1196 static inline void trace_branch_disable(void)
1197 {
1198 }
1199 #endif /* CONFIG_BRANCH_TRACER */
1200
1201 /* set ring buffers to default size if not already done so */
1202 int tracing_update_buffers(void);
1203
1204 struct ftrace_event_field {
1205 struct list_head link;
1206 const char *name;
1207 const char *type;
1208 int filter_type;
1209 int offset;
1210 int size;
1211 int is_signed;
1212 };
1213
1214 struct event_filter {
1215 int n_preds; /* Number assigned */
1216 int a_preds; /* allocated */
1217 struct filter_pred __rcu *preds;
1218 struct filter_pred __rcu *root;
1219 char *filter_string;
1220 };
1221
1222 struct event_subsystem {
1223 struct list_head list;
1224 const char *name;
1225 struct event_filter *filter;
1226 int ref_count;
1227 };
1228
1229 struct trace_subsystem_dir {
1230 struct list_head list;
1231 struct event_subsystem *subsystem;
1232 struct trace_array *tr;
1233 struct dentry *entry;
1234 int ref_count;
1235 int nr_events;
1236 };
1237
1238 extern int call_filter_check_discard(struct trace_event_call *call, void *rec,
1239 struct ring_buffer *buffer,
1240 struct ring_buffer_event *event);
1241
1242 void trace_buffer_unlock_commit_regs(struct trace_array *tr,
1243 struct ring_buffer *buffer,
1244 struct ring_buffer_event *event,
1245 unsigned long flags, int pc,
1246 struct pt_regs *regs);
1247
1248 static inline void trace_buffer_unlock_commit(struct trace_array *tr,
1249 struct ring_buffer *buffer,
1250 struct ring_buffer_event *event,
1251 unsigned long flags, int pc)
1252 {
1253 trace_buffer_unlock_commit_regs(tr, buffer, event, flags, pc, NULL);
1254 }
1255
1256 DECLARE_PER_CPU(struct ring_buffer_event *, trace_buffered_event);
1257 DECLARE_PER_CPU(int, trace_buffered_event_cnt);
1258 void trace_buffered_event_disable(void);
1259 void trace_buffered_event_enable(void);
1260
1261 static inline void
1262 __trace_event_discard_commit(struct ring_buffer *buffer,
1263 struct ring_buffer_event *event)
1264 {
1265 if (this_cpu_read(trace_buffered_event) == event) {
1266 /* Simply release the temp buffer */
1267 this_cpu_dec(trace_buffered_event_cnt);
1268 return;
1269 }
1270 ring_buffer_discard_commit(buffer, event);
1271 }
1272
1273 /*
1274 * Helper function for event_trigger_unlock_commit{_regs}().
1275 * If there are event triggers attached to this event that requires
1276 * filtering against its fields, then they wil be called as the
1277 * entry already holds the field information of the current event.
1278 *
1279 * It also checks if the event should be discarded or not.
1280 * It is to be discarded if the event is soft disabled and the
1281 * event was only recorded to process triggers, or if the event
1282 * filter is active and this event did not match the filters.
1283 *
1284 * Returns true if the event is discarded, false otherwise.
1285 */
1286 static inline bool
1287 __event_trigger_test_discard(struct trace_event_file *file,
1288 struct ring_buffer *buffer,
1289 struct ring_buffer_event *event,
1290 void *entry,
1291 enum event_trigger_type *tt)
1292 {
1293 unsigned long eflags = file->flags;
1294
1295 if (eflags & EVENT_FILE_FL_TRIGGER_COND)
1296 *tt = event_triggers_call(file, entry);
1297
1298 if (test_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags) ||
1299 (unlikely(file->flags & EVENT_FILE_FL_FILTERED) &&
1300 !filter_match_preds(file->filter, entry))) {
1301 __trace_event_discard_commit(buffer, event);
1302 return true;
1303 }
1304
1305 return false;
1306 }
1307
1308 /**
1309 * event_trigger_unlock_commit - handle triggers and finish event commit
1310 * @file: The file pointer assoctiated to the event
1311 * @buffer: The ring buffer that the event is being written to
1312 * @event: The event meta data in the ring buffer
1313 * @entry: The event itself
1314 * @irq_flags: The state of the interrupts at the start of the event
1315 * @pc: The state of the preempt count at the start of the event.
1316 *
1317 * This is a helper function to handle triggers that require data
1318 * from the event itself. It also tests the event against filters and
1319 * if the event is soft disabled and should be discarded.
1320 */
1321 static inline void
1322 event_trigger_unlock_commit(struct trace_event_file *file,
1323 struct ring_buffer *buffer,
1324 struct ring_buffer_event *event,
1325 void *entry, unsigned long irq_flags, int pc)
1326 {
1327 enum event_trigger_type tt = ETT_NONE;
1328
1329 if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1330 trace_buffer_unlock_commit(file->tr, buffer, event, irq_flags, pc);
1331
1332 if (tt)
1333 event_triggers_post_call(file, tt, entry);
1334 }
1335
1336 /**
1337 * event_trigger_unlock_commit_regs - handle triggers and finish event commit
1338 * @file: The file pointer assoctiated to the event
1339 * @buffer: The ring buffer that the event is being written to
1340 * @event: The event meta data in the ring buffer
1341 * @entry: The event itself
1342 * @irq_flags: The state of the interrupts at the start of the event
1343 * @pc: The state of the preempt count at the start of the event.
1344 *
1345 * This is a helper function to handle triggers that require data
1346 * from the event itself. It also tests the event against filters and
1347 * if the event is soft disabled and should be discarded.
1348 *
1349 * Same as event_trigger_unlock_commit() but calls
1350 * trace_buffer_unlock_commit_regs() instead of trace_buffer_unlock_commit().
1351 */
1352 static inline void
1353 event_trigger_unlock_commit_regs(struct trace_event_file *file,
1354 struct ring_buffer *buffer,
1355 struct ring_buffer_event *event,
1356 void *entry, unsigned long irq_flags, int pc,
1357 struct pt_regs *regs)
1358 {
1359 enum event_trigger_type tt = ETT_NONE;
1360
1361 if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1362 trace_buffer_unlock_commit_regs(file->tr, buffer, event,
1363 irq_flags, pc, regs);
1364
1365 if (tt)
1366 event_triggers_post_call(file, tt, entry);
1367 }
1368
1369 #define FILTER_PRED_INVALID ((unsigned short)-1)
1370 #define FILTER_PRED_IS_RIGHT (1 << 15)
1371 #define FILTER_PRED_FOLD (1 << 15)
1372
1373 /*
1374 * The max preds is the size of unsigned short with
1375 * two flags at the MSBs. One bit is used for both the IS_RIGHT
1376 * and FOLD flags. The other is reserved.
1377 *
1378 * 2^14 preds is way more than enough.
1379 */
1380 #define MAX_FILTER_PRED 16384
1381
1382 struct filter_pred;
1383 struct regex;
1384
1385 typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event);
1386
1387 typedef int (*regex_match_func)(char *str, struct regex *r, int len);
1388
1389 enum regex_type {
1390 MATCH_FULL = 0,
1391 MATCH_FRONT_ONLY,
1392 MATCH_MIDDLE_ONLY,
1393 MATCH_END_ONLY,
1394 MATCH_GLOB,
1395 };
1396
1397 struct regex {
1398 char pattern[MAX_FILTER_STR_VAL];
1399 int len;
1400 int field_len;
1401 regex_match_func match;
1402 };
1403
1404 struct filter_pred {
1405 filter_pred_fn_t fn;
1406 u64 val;
1407 struct regex regex;
1408 unsigned short *ops;
1409 struct ftrace_event_field *field;
1410 int offset;
1411 int not;
1412 int op;
1413 unsigned short index;
1414 unsigned short parent;
1415 unsigned short left;
1416 unsigned short right;
1417 };
1418
1419 static inline bool is_string_field(struct ftrace_event_field *field)
1420 {
1421 return field->filter_type == FILTER_DYN_STRING ||
1422 field->filter_type == FILTER_STATIC_STRING ||
1423 field->filter_type == FILTER_PTR_STRING ||
1424 field->filter_type == FILTER_COMM;
1425 }
1426
1427 static inline bool is_function_field(struct ftrace_event_field *field)
1428 {
1429 return field->filter_type == FILTER_TRACE_FN;
1430 }
1431
1432 extern enum regex_type
1433 filter_parse_regex(char *buff, int len, char **search, int *not);
1434 extern void print_event_filter(struct trace_event_file *file,
1435 struct trace_seq *s);
1436 extern int apply_event_filter(struct trace_event_file *file,
1437 char *filter_string);
1438 extern int apply_subsystem_event_filter(struct trace_subsystem_dir *dir,
1439 char *filter_string);
1440 extern void print_subsystem_event_filter(struct event_subsystem *system,
1441 struct trace_seq *s);
1442 extern int filter_assign_type(const char *type);
1443 extern int create_event_filter(struct trace_event_call *call,
1444 char *filter_str, bool set_str,
1445 struct event_filter **filterp);
1446 extern void free_event_filter(struct event_filter *filter);
1447
1448 struct ftrace_event_field *
1449 trace_find_event_field(struct trace_event_call *call, char *name);
1450
1451 extern void trace_event_enable_cmd_record(bool enable);
1452 extern void trace_event_enable_tgid_record(bool enable);
1453
1454 extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
1455 extern int event_trace_del_tracer(struct trace_array *tr);
1456
1457 extern struct trace_event_file *find_event_file(struct trace_array *tr,
1458 const char *system,
1459 const char *event);
1460
1461 static inline void *event_file_data(struct file *filp)
1462 {
1463 return ACCESS_ONCE(file_inode(filp)->i_private);
1464 }
1465
1466 extern struct mutex event_mutex;
1467 extern struct list_head ftrace_events;
1468
1469 extern const struct file_operations event_trigger_fops;
1470 extern const struct file_operations event_hist_fops;
1471
1472 #ifdef CONFIG_HIST_TRIGGERS
1473 extern int register_trigger_hist_cmd(void);
1474 extern int register_trigger_hist_enable_disable_cmds(void);
1475 #else
1476 static inline int register_trigger_hist_cmd(void) { return 0; }
1477 static inline int register_trigger_hist_enable_disable_cmds(void) { return 0; }
1478 #endif
1479
1480 extern int register_trigger_cmds(void);
1481 extern void clear_event_triggers(struct trace_array *tr);
1482
1483 struct event_trigger_data {
1484 unsigned long count;
1485 int ref;
1486 struct event_trigger_ops *ops;
1487 struct event_command *cmd_ops;
1488 struct event_filter __rcu *filter;
1489 char *filter_str;
1490 void *private_data;
1491 bool paused;
1492 bool paused_tmp;
1493 struct list_head list;
1494 char *name;
1495 struct list_head named_list;
1496 struct event_trigger_data *named_data;
1497 };
1498
1499 /* Avoid typos */
1500 #define ENABLE_EVENT_STR "enable_event"
1501 #define DISABLE_EVENT_STR "disable_event"
1502 #define ENABLE_HIST_STR "enable_hist"
1503 #define DISABLE_HIST_STR "disable_hist"
1504
1505 struct enable_trigger_data {
1506 struct trace_event_file *file;
1507 bool enable;
1508 bool hist;
1509 };
1510
1511 extern int event_enable_trigger_print(struct seq_file *m,
1512 struct event_trigger_ops *ops,
1513 struct event_trigger_data *data);
1514 extern void event_enable_trigger_free(struct event_trigger_ops *ops,
1515 struct event_trigger_data *data);
1516 extern int event_enable_trigger_func(struct event_command *cmd_ops,
1517 struct trace_event_file *file,
1518 char *glob, char *cmd, char *param);
1519 extern int event_enable_register_trigger(char *glob,
1520 struct event_trigger_ops *ops,
1521 struct event_trigger_data *data,
1522 struct trace_event_file *file);
1523 extern void event_enable_unregister_trigger(char *glob,
1524 struct event_trigger_ops *ops,
1525 struct event_trigger_data *test,
1526 struct trace_event_file *file);
1527 extern void trigger_data_free(struct event_trigger_data *data);
1528 extern int event_trigger_init(struct event_trigger_ops *ops,
1529 struct event_trigger_data *data);
1530 extern int trace_event_trigger_enable_disable(struct trace_event_file *file,
1531 int trigger_enable);
1532 extern void update_cond_flag(struct trace_event_file *file);
1533 extern void unregister_trigger(char *glob, struct event_trigger_ops *ops,
1534 struct event_trigger_data *test,
1535 struct trace_event_file *file);
1536 extern int set_trigger_filter(char *filter_str,
1537 struct event_trigger_data *trigger_data,
1538 struct trace_event_file *file);
1539 extern struct event_trigger_data *find_named_trigger(const char *name);
1540 extern bool is_named_trigger(struct event_trigger_data *test);
1541 extern int save_named_trigger(const char *name,
1542 struct event_trigger_data *data);
1543 extern void del_named_trigger(struct event_trigger_data *data);
1544 extern void pause_named_trigger(struct event_trigger_data *data);
1545 extern void unpause_named_trigger(struct event_trigger_data *data);
1546 extern void set_named_trigger_data(struct event_trigger_data *data,
1547 struct event_trigger_data *named_data);
1548 extern int register_event_command(struct event_command *cmd);
1549 extern int unregister_event_command(struct event_command *cmd);
1550 extern int register_trigger_hist_enable_disable_cmds(void);
1551
1552 /**
1553 * struct event_trigger_ops - callbacks for trace event triggers
1554 *
1555 * The methods in this structure provide per-event trigger hooks for
1556 * various trigger operations.
1557 *
1558 * All the methods below, except for @init() and @free(), must be
1559 * implemented.
1560 *
1561 * @func: The trigger 'probe' function called when the triggering
1562 * event occurs. The data passed into this callback is the data
1563 * that was supplied to the event_command @reg() function that
1564 * registered the trigger (see struct event_command) along with
1565 * the trace record, rec.
1566 *
1567 * @init: An optional initialization function called for the trigger
1568 * when the trigger is registered (via the event_command reg()
1569 * function). This can be used to perform per-trigger
1570 * initialization such as incrementing a per-trigger reference
1571 * count, for instance. This is usually implemented by the
1572 * generic utility function @event_trigger_init() (see
1573 * trace_event_triggers.c).
1574 *
1575 * @free: An optional de-initialization function called for the
1576 * trigger when the trigger is unregistered (via the
1577 * event_command @reg() function). This can be used to perform
1578 * per-trigger de-initialization such as decrementing a
1579 * per-trigger reference count and freeing corresponding trigger
1580 * data, for instance. This is usually implemented by the
1581 * generic utility function @event_trigger_free() (see
1582 * trace_event_triggers.c).
1583 *
1584 * @print: The callback function invoked to have the trigger print
1585 * itself. This is usually implemented by a wrapper function
1586 * that calls the generic utility function @event_trigger_print()
1587 * (see trace_event_triggers.c).
1588 */
1589 struct event_trigger_ops {
1590 void (*func)(struct event_trigger_data *data,
1591 void *rec);
1592 int (*init)(struct event_trigger_ops *ops,
1593 struct event_trigger_data *data);
1594 void (*free)(struct event_trigger_ops *ops,
1595 struct event_trigger_data *data);
1596 int (*print)(struct seq_file *m,
1597 struct event_trigger_ops *ops,
1598 struct event_trigger_data *data);
1599 };
1600
1601 /**
1602 * struct event_command - callbacks and data members for event commands
1603 *
1604 * Event commands are invoked by users by writing the command name
1605 * into the 'trigger' file associated with a trace event. The
1606 * parameters associated with a specific invocation of an event
1607 * command are used to create an event trigger instance, which is
1608 * added to the list of trigger instances associated with that trace
1609 * event. When the event is hit, the set of triggers associated with
1610 * that event is invoked.
1611 *
1612 * The data members in this structure provide per-event command data
1613 * for various event commands.
1614 *
1615 * All the data members below, except for @post_trigger, must be set
1616 * for each event command.
1617 *
1618 * @name: The unique name that identifies the event command. This is
1619 * the name used when setting triggers via trigger files.
1620 *
1621 * @trigger_type: A unique id that identifies the event command
1622 * 'type'. This value has two purposes, the first to ensure that
1623 * only one trigger of the same type can be set at a given time
1624 * for a particular event e.g. it doesn't make sense to have both
1625 * a traceon and traceoff trigger attached to a single event at
1626 * the same time, so traceon and traceoff have the same type
1627 * though they have different names. The @trigger_type value is
1628 * also used as a bit value for deferring the actual trigger
1629 * action until after the current event is finished. Some
1630 * commands need to do this if they themselves log to the trace
1631 * buffer (see the @post_trigger() member below). @trigger_type
1632 * values are defined by adding new values to the trigger_type
1633 * enum in include/linux/trace_events.h.
1634 *
1635 * @flags: See the enum event_command_flags below.
1636 *
1637 * All the methods below, except for @set_filter() and @unreg_all(),
1638 * must be implemented.
1639 *
1640 * @func: The callback function responsible for parsing and
1641 * registering the trigger written to the 'trigger' file by the
1642 * user. It allocates the trigger instance and registers it with
1643 * the appropriate trace event. It makes use of the other
1644 * event_command callback functions to orchestrate this, and is
1645 * usually implemented by the generic utility function
1646 * @event_trigger_callback() (see trace_event_triggers.c).
1647 *
1648 * @reg: Adds the trigger to the list of triggers associated with the
1649 * event, and enables the event trigger itself, after
1650 * initializing it (via the event_trigger_ops @init() function).
1651 * This is also where commands can use the @trigger_type value to
1652 * make the decision as to whether or not multiple instances of
1653 * the trigger should be allowed. This is usually implemented by
1654 * the generic utility function @register_trigger() (see
1655 * trace_event_triggers.c).
1656 *
1657 * @unreg: Removes the trigger from the list of triggers associated
1658 * with the event, and disables the event trigger itself, after
1659 * initializing it (via the event_trigger_ops @free() function).
1660 * This is usually implemented by the generic utility function
1661 * @unregister_trigger() (see trace_event_triggers.c).
1662 *
1663 * @unreg_all: An optional function called to remove all the triggers
1664 * from the list of triggers associated with the event. Called
1665 * when a trigger file is opened in truncate mode.
1666 *
1667 * @set_filter: An optional function called to parse and set a filter
1668 * for the trigger. If no @set_filter() method is set for the
1669 * event command, filters set by the user for the command will be
1670 * ignored. This is usually implemented by the generic utility
1671 * function @set_trigger_filter() (see trace_event_triggers.c).
1672 *
1673 * @get_trigger_ops: The callback function invoked to retrieve the
1674 * event_trigger_ops implementation associated with the command.
1675 */
1676 struct event_command {
1677 struct list_head list;
1678 char *name;
1679 enum event_trigger_type trigger_type;
1680 int flags;
1681 int (*func)(struct event_command *cmd_ops,
1682 struct trace_event_file *file,
1683 char *glob, char *cmd, char *params);
1684 int (*reg)(char *glob,
1685 struct event_trigger_ops *ops,
1686 struct event_trigger_data *data,
1687 struct trace_event_file *file);
1688 void (*unreg)(char *glob,
1689 struct event_trigger_ops *ops,
1690 struct event_trigger_data *data,
1691 struct trace_event_file *file);
1692 void (*unreg_all)(struct trace_event_file *file);
1693 int (*set_filter)(char *filter_str,
1694 struct event_trigger_data *data,
1695 struct trace_event_file *file);
1696 struct event_trigger_ops *(*get_trigger_ops)(char *cmd, char *param);
1697 };
1698
1699 /**
1700 * enum event_command_flags - flags for struct event_command
1701 *
1702 * @POST_TRIGGER: A flag that says whether or not this command needs
1703 * to have its action delayed until after the current event has
1704 * been closed. Some triggers need to avoid being invoked while
1705 * an event is currently in the process of being logged, since
1706 * the trigger may itself log data into the trace buffer. Thus
1707 * we make sure the current event is committed before invoking
1708 * those triggers. To do that, the trigger invocation is split
1709 * in two - the first part checks the filter using the current
1710 * trace record; if a command has the @post_trigger flag set, it
1711 * sets a bit for itself in the return value, otherwise it
1712 * directly invokes the trigger. Once all commands have been
1713 * either invoked or set their return flag, the current record is
1714 * either committed or discarded. At that point, if any commands
1715 * have deferred their triggers, those commands are finally
1716 * invoked following the close of the current event. In other
1717 * words, if the event_trigger_ops @func() probe implementation
1718 * itself logs to the trace buffer, this flag should be set,
1719 * otherwise it can be left unspecified.
1720 *
1721 * @NEEDS_REC: A flag that says whether or not this command needs
1722 * access to the trace record in order to perform its function,
1723 * regardless of whether or not it has a filter associated with
1724 * it (filters make a trigger require access to the trace record
1725 * but are not always present).
1726 */
1727 enum event_command_flags {
1728 EVENT_CMD_FL_POST_TRIGGER = 1,
1729 EVENT_CMD_FL_NEEDS_REC = 2,
1730 };
1731
1732 static inline bool event_command_post_trigger(struct event_command *cmd_ops)
1733 {
1734 return cmd_ops->flags & EVENT_CMD_FL_POST_TRIGGER;
1735 }
1736
1737 static inline bool event_command_needs_rec(struct event_command *cmd_ops)
1738 {
1739 return cmd_ops->flags & EVENT_CMD_FL_NEEDS_REC;
1740 }
1741
1742 extern int trace_event_enable_disable(struct trace_event_file *file,
1743 int enable, int soft_disable);
1744 extern int tracing_alloc_snapshot(void);
1745
1746 extern const char *__start___trace_bprintk_fmt[];
1747 extern const char *__stop___trace_bprintk_fmt[];
1748
1749 extern const char *__start___tracepoint_str[];
1750 extern const char *__stop___tracepoint_str[];
1751
1752 void trace_printk_control(bool enabled);
1753 void trace_printk_init_buffers(void);
1754 void trace_printk_start_comm(void);
1755 int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set);
1756 int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled);
1757
1758 /*
1759 * Normal trace_printk() and friends allocates special buffers
1760 * to do the manipulation, as well as saves the print formats
1761 * into sections to display. But the trace infrastructure wants
1762 * to use these without the added overhead at the price of being
1763 * a bit slower (used mainly for warnings, where we don't care
1764 * about performance). The internal_trace_puts() is for such
1765 * a purpose.
1766 */
1767 #define internal_trace_puts(str) __trace_puts(_THIS_IP_, str, strlen(str))
1768
1769 #undef FTRACE_ENTRY
1770 #define FTRACE_ENTRY(call, struct_name, id, tstruct, print, filter) \
1771 extern struct trace_event_call \
1772 __aligned(4) event_##call;
1773 #undef FTRACE_ENTRY_DUP
1774 #define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print, filter) \
1775 FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print), \
1776 filter)
1777 #undef FTRACE_ENTRY_PACKED
1778 #define FTRACE_ENTRY_PACKED(call, struct_name, id, tstruct, print, filter) \
1779 FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print), \
1780 filter)
1781
1782 #include "trace_entries.h"
1783
1784 #if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_FUNCTION_TRACER)
1785 int perf_ftrace_event_register(struct trace_event_call *call,
1786 enum trace_reg type, void *data);
1787 #else
1788 #define perf_ftrace_event_register NULL
1789 #endif
1790
1791 #ifdef CONFIG_FTRACE_SYSCALLS
1792 void init_ftrace_syscalls(void);
1793 const char *get_syscall_name(int syscall);
1794 #else
1795 static inline void init_ftrace_syscalls(void) { }
1796 static inline const char *get_syscall_name(int syscall)
1797 {
1798 return NULL;
1799 }
1800 #endif
1801
1802 #ifdef CONFIG_EVENT_TRACING
1803 void trace_event_init(void);
1804 void trace_event_eval_update(struct trace_eval_map **map, int len);
1805 #else
1806 static inline void __init trace_event_init(void) { }
1807 static inline void trace_event_eval_update(struct trace_eval_map **map, int len) { }
1808 #endif
1809
1810 extern struct trace_iterator *tracepoint_print_iter;
1811
1812 #endif /* _LINUX_KERNEL_TRACE_H */