0bebb5c348b8268eff6135f24f1635c0adf2dbb1
[deliverable/linux.git] / include / linux / ftrace_event.h
1
2 #ifndef _LINUX_FTRACE_EVENT_H
3 #define _LINUX_FTRACE_EVENT_H
4
5 #include <linux/ring_buffer.h>
6 #include <linux/trace_seq.h>
7 #include <linux/percpu.h>
8 #include <linux/hardirq.h>
9 #include <linux/perf_event.h>
10 #include <linux/tracepoint.h>
11
12 struct trace_array;
13 struct trace_buffer;
14 struct tracer;
15 struct dentry;
16
17 struct trace_print_flags {
18 unsigned long mask;
19 const char *name;
20 };
21
22 struct trace_print_flags_u64 {
23 unsigned long long mask;
24 const char *name;
25 };
26
27 const char *ftrace_print_flags_seq(struct trace_seq *p, const char *delim,
28 unsigned long flags,
29 const struct trace_print_flags *flag_array);
30
31 const char *ftrace_print_symbols_seq(struct trace_seq *p, unsigned long val,
32 const struct trace_print_flags *symbol_array);
33
34 #if BITS_PER_LONG == 32
35 const char *ftrace_print_symbols_seq_u64(struct trace_seq *p,
36 unsigned long long val,
37 const struct trace_print_flags_u64
38 *symbol_array);
39 #endif
40
41 const char *ftrace_print_bitmask_seq(struct trace_seq *p, void *bitmask_ptr,
42 unsigned int bitmask_size);
43
44 const char *ftrace_print_hex_seq(struct trace_seq *p,
45 const unsigned char *buf, int len);
46
47 struct trace_iterator;
48 struct trace_event;
49
50 int ftrace_raw_output_prep(struct trace_iterator *iter,
51 struct trace_event *event);
52
53 /*
54 * The trace entry - the most basic unit of tracing. This is what
55 * is printed in the end as a single line in the trace output, such as:
56 *
57 * bash-15816 [01] 235.197585: idle_cpu <- irq_enter
58 */
59 struct trace_entry {
60 unsigned short type;
61 unsigned char flags;
62 unsigned char preempt_count;
63 int pid;
64 };
65
66 #define FTRACE_MAX_EVENT \
67 ((1 << (sizeof(((struct trace_entry *)0)->type) * 8)) - 1)
68
69 /*
70 * Trace iterator - used by printout routines who present trace
71 * results to users and which routines might sleep, etc:
72 */
73 struct trace_iterator {
74 struct trace_array *tr;
75 struct tracer *trace;
76 struct trace_buffer *trace_buffer;
77 void *private;
78 int cpu_file;
79 struct mutex mutex;
80 struct ring_buffer_iter **buffer_iter;
81 unsigned long iter_flags;
82
83 /* trace_seq for __print_flags() and __print_symbolic() etc. */
84 struct trace_seq tmp_seq;
85
86 cpumask_var_t started;
87
88 /* it's true when current open file is snapshot */
89 bool snapshot;
90
91 /* The below is zeroed out in pipe_read */
92 struct trace_seq seq;
93 struct trace_entry *ent;
94 unsigned long lost_events;
95 int leftover;
96 int ent_size;
97 int cpu;
98 u64 ts;
99
100 loff_t pos;
101 long idx;
102
103 /* All new field here will be zeroed out in pipe_read */
104 };
105
106 enum trace_iter_flags {
107 TRACE_FILE_LAT_FMT = 1,
108 TRACE_FILE_ANNOTATE = 2,
109 TRACE_FILE_TIME_IN_NS = 4,
110 };
111
112
113 typedef enum print_line_t (*trace_print_func)(struct trace_iterator *iter,
114 int flags, struct trace_event *event);
115
116 struct trace_event_functions {
117 trace_print_func trace;
118 trace_print_func raw;
119 trace_print_func hex;
120 trace_print_func binary;
121 };
122
123 struct trace_event {
124 struct hlist_node node;
125 struct list_head list;
126 int type;
127 struct trace_event_functions *funcs;
128 };
129
130 extern int register_ftrace_event(struct trace_event *event);
131 extern int unregister_ftrace_event(struct trace_event *event);
132
133 /* Return values for print_line callback */
134 enum print_line_t {
135 TRACE_TYPE_PARTIAL_LINE = 0, /* Retry after flushing the seq */
136 TRACE_TYPE_HANDLED = 1,
137 TRACE_TYPE_UNHANDLED = 2, /* Relay to other output functions */
138 TRACE_TYPE_NO_CONSUME = 3 /* Handled but ask to not consume */
139 };
140
141 /*
142 * Several functions return TRACE_TYPE_PARTIAL_LINE if the trace_seq
143 * overflowed, and TRACE_TYPE_HANDLED otherwise. This helper function
144 * simplifies those functions and keeps them in sync.
145 */
146 static inline enum print_line_t trace_handle_return(struct trace_seq *s)
147 {
148 return trace_seq_has_overflowed(s) ?
149 TRACE_TYPE_PARTIAL_LINE : TRACE_TYPE_HANDLED;
150 }
151
152 void tracing_generic_entry_update(struct trace_entry *entry,
153 unsigned long flags,
154 int pc);
155 struct ftrace_event_file;
156
157 struct ring_buffer_event *
158 trace_event_buffer_lock_reserve(struct ring_buffer **current_buffer,
159 struct ftrace_event_file *ftrace_file,
160 int type, unsigned long len,
161 unsigned long flags, int pc);
162 struct ring_buffer_event *
163 trace_current_buffer_lock_reserve(struct ring_buffer **current_buffer,
164 int type, unsigned long len,
165 unsigned long flags, int pc);
166 void trace_current_buffer_unlock_commit(struct ring_buffer *buffer,
167 struct ring_buffer_event *event,
168 unsigned long flags, int pc);
169 void trace_buffer_unlock_commit(struct ring_buffer *buffer,
170 struct ring_buffer_event *event,
171 unsigned long flags, int pc);
172 void trace_buffer_unlock_commit_regs(struct ring_buffer *buffer,
173 struct ring_buffer_event *event,
174 unsigned long flags, int pc,
175 struct pt_regs *regs);
176 void trace_current_buffer_discard_commit(struct ring_buffer *buffer,
177 struct ring_buffer_event *event);
178
179 void tracing_record_cmdline(struct task_struct *tsk);
180
181 int ftrace_output_call(struct trace_iterator *iter, char *name, char *fmt, ...);
182
183 struct event_filter;
184
185 enum trace_reg {
186 TRACE_REG_REGISTER,
187 TRACE_REG_UNREGISTER,
188 #ifdef CONFIG_PERF_EVENTS
189 TRACE_REG_PERF_REGISTER,
190 TRACE_REG_PERF_UNREGISTER,
191 TRACE_REG_PERF_OPEN,
192 TRACE_REG_PERF_CLOSE,
193 TRACE_REG_PERF_ADD,
194 TRACE_REG_PERF_DEL,
195 #endif
196 };
197
198 struct ftrace_event_call;
199
200 struct ftrace_event_class {
201 char *system;
202 void *probe;
203 #ifdef CONFIG_PERF_EVENTS
204 void *perf_probe;
205 #endif
206 int (*reg)(struct ftrace_event_call *event,
207 enum trace_reg type, void *data);
208 int (*define_fields)(struct ftrace_event_call *);
209 struct list_head *(*get_fields)(struct ftrace_event_call *);
210 struct list_head fields;
211 int (*raw_init)(struct ftrace_event_call *);
212 };
213
214 extern int ftrace_event_reg(struct ftrace_event_call *event,
215 enum trace_reg type, void *data);
216
217 int ftrace_output_event(struct trace_iterator *iter, struct ftrace_event_call *event,
218 char *fmt, ...);
219
220 int ftrace_event_define_field(struct ftrace_event_call *call,
221 char *type, int len, char *item, int offset,
222 int field_size, int sign, int filter);
223
224 struct ftrace_event_buffer {
225 struct ring_buffer *buffer;
226 struct ring_buffer_event *event;
227 struct ftrace_event_file *ftrace_file;
228 void *entry;
229 unsigned long flags;
230 int pc;
231 };
232
233 void *ftrace_event_buffer_reserve(struct ftrace_event_buffer *fbuffer,
234 struct ftrace_event_file *ftrace_file,
235 unsigned long len);
236
237 void ftrace_event_buffer_commit(struct ftrace_event_buffer *fbuffer);
238
239 int ftrace_event_define_field(struct ftrace_event_call *call,
240 char *type, int len, char *item, int offset,
241 int field_size, int sign, int filter);
242
243 enum {
244 TRACE_EVENT_FL_FILTERED_BIT,
245 TRACE_EVENT_FL_CAP_ANY_BIT,
246 TRACE_EVENT_FL_NO_SET_FILTER_BIT,
247 TRACE_EVENT_FL_IGNORE_ENABLE_BIT,
248 TRACE_EVENT_FL_WAS_ENABLED_BIT,
249 TRACE_EVENT_FL_USE_CALL_FILTER_BIT,
250 TRACE_EVENT_FL_TRACEPOINT_BIT,
251 };
252
253 /*
254 * Event flags:
255 * FILTERED - The event has a filter attached
256 * CAP_ANY - Any user can enable for perf
257 * NO_SET_FILTER - Set when filter has error and is to be ignored
258 * IGNORE_ENABLE - For ftrace internal events, do not enable with debugfs file
259 * WAS_ENABLED - Set and stays set when an event was ever enabled
260 * (used for module unloading, if a module event is enabled,
261 * it is best to clear the buffers that used it).
262 * USE_CALL_FILTER - For ftrace internal events, don't use file filter
263 * TRACEPOINT - Event is a tracepoint
264 */
265 enum {
266 TRACE_EVENT_FL_FILTERED = (1 << TRACE_EVENT_FL_FILTERED_BIT),
267 TRACE_EVENT_FL_CAP_ANY = (1 << TRACE_EVENT_FL_CAP_ANY_BIT),
268 TRACE_EVENT_FL_NO_SET_FILTER = (1 << TRACE_EVENT_FL_NO_SET_FILTER_BIT),
269 TRACE_EVENT_FL_IGNORE_ENABLE = (1 << TRACE_EVENT_FL_IGNORE_ENABLE_BIT),
270 TRACE_EVENT_FL_WAS_ENABLED = (1 << TRACE_EVENT_FL_WAS_ENABLED_BIT),
271 TRACE_EVENT_FL_USE_CALL_FILTER = (1 << TRACE_EVENT_FL_USE_CALL_FILTER_BIT),
272 TRACE_EVENT_FL_TRACEPOINT = (1 << TRACE_EVENT_FL_TRACEPOINT_BIT),
273 };
274
275 struct ftrace_event_call {
276 struct list_head list;
277 struct ftrace_event_class *class;
278 union {
279 char *name;
280 /* Set TRACE_EVENT_FL_TRACEPOINT flag when using "tp" */
281 struct tracepoint *tp;
282 };
283 struct trace_event event;
284 const char *print_fmt;
285 struct event_filter *filter;
286 void *mod;
287 void *data;
288 /*
289 * bit 0: filter_active
290 * bit 1: allow trace by non root (cap any)
291 * bit 2: failed to apply filter
292 * bit 3: ftrace internal event (do not enable)
293 * bit 4: Event was enabled by module
294 * bit 5: use call filter rather than file filter
295 * bit 6: Event is a tracepoint
296 */
297 int flags; /* static flags of different events */
298
299 #ifdef CONFIG_PERF_EVENTS
300 int perf_refcount;
301 struct hlist_head __percpu *perf_events;
302
303 int (*perf_perm)(struct ftrace_event_call *,
304 struct perf_event *);
305 #endif
306 };
307
308 static inline const char *
309 ftrace_event_name(struct ftrace_event_call *call)
310 {
311 if (call->flags & TRACE_EVENT_FL_TRACEPOINT)
312 return call->tp ? call->tp->name : NULL;
313 else
314 return call->name;
315 }
316
317 struct trace_array;
318 struct ftrace_subsystem_dir;
319
320 enum {
321 FTRACE_EVENT_FL_ENABLED_BIT,
322 FTRACE_EVENT_FL_RECORDED_CMD_BIT,
323 FTRACE_EVENT_FL_FILTERED_BIT,
324 FTRACE_EVENT_FL_NO_SET_FILTER_BIT,
325 FTRACE_EVENT_FL_SOFT_MODE_BIT,
326 FTRACE_EVENT_FL_SOFT_DISABLED_BIT,
327 FTRACE_EVENT_FL_TRIGGER_MODE_BIT,
328 FTRACE_EVENT_FL_TRIGGER_COND_BIT,
329 };
330
331 /*
332 * Ftrace event file flags:
333 * ENABLED - The event is enabled
334 * RECORDED_CMD - The comms should be recorded at sched_switch
335 * FILTERED - The event has a filter attached
336 * NO_SET_FILTER - Set when filter has error and is to be ignored
337 * SOFT_MODE - The event is enabled/disabled by SOFT_DISABLED
338 * SOFT_DISABLED - When set, do not trace the event (even though its
339 * tracepoint may be enabled)
340 * TRIGGER_MODE - When set, invoke the triggers associated with the event
341 * TRIGGER_COND - When set, one or more triggers has an associated filter
342 */
343 enum {
344 FTRACE_EVENT_FL_ENABLED = (1 << FTRACE_EVENT_FL_ENABLED_BIT),
345 FTRACE_EVENT_FL_RECORDED_CMD = (1 << FTRACE_EVENT_FL_RECORDED_CMD_BIT),
346 FTRACE_EVENT_FL_FILTERED = (1 << FTRACE_EVENT_FL_FILTERED_BIT),
347 FTRACE_EVENT_FL_NO_SET_FILTER = (1 << FTRACE_EVENT_FL_NO_SET_FILTER_BIT),
348 FTRACE_EVENT_FL_SOFT_MODE = (1 << FTRACE_EVENT_FL_SOFT_MODE_BIT),
349 FTRACE_EVENT_FL_SOFT_DISABLED = (1 << FTRACE_EVENT_FL_SOFT_DISABLED_BIT),
350 FTRACE_EVENT_FL_TRIGGER_MODE = (1 << FTRACE_EVENT_FL_TRIGGER_MODE_BIT),
351 FTRACE_EVENT_FL_TRIGGER_COND = (1 << FTRACE_EVENT_FL_TRIGGER_COND_BIT),
352 };
353
354 struct ftrace_event_file {
355 struct list_head list;
356 struct ftrace_event_call *event_call;
357 struct event_filter *filter;
358 struct dentry *dir;
359 struct trace_array *tr;
360 struct ftrace_subsystem_dir *system;
361 struct list_head triggers;
362
363 /*
364 * 32 bit flags:
365 * bit 0: enabled
366 * bit 1: enabled cmd record
367 * bit 2: enable/disable with the soft disable bit
368 * bit 3: soft disabled
369 * bit 4: trigger enabled
370 *
371 * Note: The bits must be set atomically to prevent races
372 * from other writers. Reads of flags do not need to be in
373 * sync as they occur in critical sections. But the way flags
374 * is currently used, these changes do not affect the code
375 * except that when a change is made, it may have a slight
376 * delay in propagating the changes to other CPUs due to
377 * caching and such. Which is mostly OK ;-)
378 */
379 unsigned long flags;
380 atomic_t sm_ref; /* soft-mode reference counter */
381 atomic_t tm_ref; /* trigger-mode reference counter */
382 };
383
384 #define __TRACE_EVENT_FLAGS(name, value) \
385 static int __init trace_init_flags_##name(void) \
386 { \
387 event_##name.flags |= value; \
388 return 0; \
389 } \
390 early_initcall(trace_init_flags_##name);
391
392 #define __TRACE_EVENT_PERF_PERM(name, expr...) \
393 static int perf_perm_##name(struct ftrace_event_call *tp_event, \
394 struct perf_event *p_event) \
395 { \
396 return ({ expr; }); \
397 } \
398 static int __init trace_init_perf_perm_##name(void) \
399 { \
400 event_##name.perf_perm = &perf_perm_##name; \
401 return 0; \
402 } \
403 early_initcall(trace_init_perf_perm_##name);
404
405 #define PERF_MAX_TRACE_SIZE 2048
406
407 #define MAX_FILTER_STR_VAL 256 /* Should handle KSYM_SYMBOL_LEN */
408
409 enum event_trigger_type {
410 ETT_NONE = (0),
411 ETT_TRACE_ONOFF = (1 << 0),
412 ETT_SNAPSHOT = (1 << 1),
413 ETT_STACKTRACE = (1 << 2),
414 ETT_EVENT_ENABLE = (1 << 3),
415 };
416
417 extern int filter_match_preds(struct event_filter *filter, void *rec);
418
419 extern int filter_check_discard(struct ftrace_event_file *file, void *rec,
420 struct ring_buffer *buffer,
421 struct ring_buffer_event *event);
422 extern int call_filter_check_discard(struct ftrace_event_call *call, void *rec,
423 struct ring_buffer *buffer,
424 struct ring_buffer_event *event);
425 extern enum event_trigger_type event_triggers_call(struct ftrace_event_file *file,
426 void *rec);
427 extern void event_triggers_post_call(struct ftrace_event_file *file,
428 enum event_trigger_type tt);
429
430 /**
431 * ftrace_trigger_soft_disabled - do triggers and test if soft disabled
432 * @file: The file pointer of the event to test
433 *
434 * If any triggers without filters are attached to this event, they
435 * will be called here. If the event is soft disabled and has no
436 * triggers that require testing the fields, it will return true,
437 * otherwise false.
438 */
439 static inline bool
440 ftrace_trigger_soft_disabled(struct ftrace_event_file *file)
441 {
442 unsigned long eflags = file->flags;
443
444 if (!(eflags & FTRACE_EVENT_FL_TRIGGER_COND)) {
445 if (eflags & FTRACE_EVENT_FL_TRIGGER_MODE)
446 event_triggers_call(file, NULL);
447 if (eflags & FTRACE_EVENT_FL_SOFT_DISABLED)
448 return true;
449 }
450 return false;
451 }
452
453 /*
454 * Helper function for event_trigger_unlock_commit{_regs}().
455 * If there are event triggers attached to this event that requires
456 * filtering against its fields, then they wil be called as the
457 * entry already holds the field information of the current event.
458 *
459 * It also checks if the event should be discarded or not.
460 * It is to be discarded if the event is soft disabled and the
461 * event was only recorded to process triggers, or if the event
462 * filter is active and this event did not match the filters.
463 *
464 * Returns true if the event is discarded, false otherwise.
465 */
466 static inline bool
467 __event_trigger_test_discard(struct ftrace_event_file *file,
468 struct ring_buffer *buffer,
469 struct ring_buffer_event *event,
470 void *entry,
471 enum event_trigger_type *tt)
472 {
473 unsigned long eflags = file->flags;
474
475 if (eflags & FTRACE_EVENT_FL_TRIGGER_COND)
476 *tt = event_triggers_call(file, entry);
477
478 if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags))
479 ring_buffer_discard_commit(buffer, event);
480 else if (!filter_check_discard(file, entry, buffer, event))
481 return false;
482
483 return true;
484 }
485
486 /**
487 * event_trigger_unlock_commit - handle triggers and finish event commit
488 * @file: The file pointer assoctiated to the event
489 * @buffer: The ring buffer that the event is being written to
490 * @event: The event meta data in the ring buffer
491 * @entry: The event itself
492 * @irq_flags: The state of the interrupts at the start of the event
493 * @pc: The state of the preempt count at the start of the event.
494 *
495 * This is a helper function to handle triggers that require data
496 * from the event itself. It also tests the event against filters and
497 * if the event is soft disabled and should be discarded.
498 */
499 static inline void
500 event_trigger_unlock_commit(struct ftrace_event_file *file,
501 struct ring_buffer *buffer,
502 struct ring_buffer_event *event,
503 void *entry, unsigned long irq_flags, int pc)
504 {
505 enum event_trigger_type tt = ETT_NONE;
506
507 if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
508 trace_buffer_unlock_commit(buffer, event, irq_flags, pc);
509
510 if (tt)
511 event_triggers_post_call(file, tt);
512 }
513
514 /**
515 * event_trigger_unlock_commit_regs - handle triggers and finish event commit
516 * @file: The file pointer assoctiated to the event
517 * @buffer: The ring buffer that the event is being written to
518 * @event: The event meta data in the ring buffer
519 * @entry: The event itself
520 * @irq_flags: The state of the interrupts at the start of the event
521 * @pc: The state of the preempt count at the start of the event.
522 *
523 * This is a helper function to handle triggers that require data
524 * from the event itself. It also tests the event against filters and
525 * if the event is soft disabled and should be discarded.
526 *
527 * Same as event_trigger_unlock_commit() but calls
528 * trace_buffer_unlock_commit_regs() instead of trace_buffer_unlock_commit().
529 */
530 static inline void
531 event_trigger_unlock_commit_regs(struct ftrace_event_file *file,
532 struct ring_buffer *buffer,
533 struct ring_buffer_event *event,
534 void *entry, unsigned long irq_flags, int pc,
535 struct pt_regs *regs)
536 {
537 enum event_trigger_type tt = ETT_NONE;
538
539 if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
540 trace_buffer_unlock_commit_regs(buffer, event,
541 irq_flags, pc, regs);
542
543 if (tt)
544 event_triggers_post_call(file, tt);
545 }
546
547 enum {
548 FILTER_OTHER = 0,
549 FILTER_STATIC_STRING,
550 FILTER_DYN_STRING,
551 FILTER_PTR_STRING,
552 FILTER_TRACE_FN,
553 };
554
555 extern int trace_event_raw_init(struct ftrace_event_call *call);
556 extern int trace_define_field(struct ftrace_event_call *call, const char *type,
557 const char *name, int offset, int size,
558 int is_signed, int filter_type);
559 extern int trace_add_event_call(struct ftrace_event_call *call);
560 extern int trace_remove_event_call(struct ftrace_event_call *call);
561
562 #define is_signed_type(type) (((type)(-1)) < (type)1)
563
564 int trace_set_clr_event(const char *system, const char *event, int set);
565
566 /*
567 * The double __builtin_constant_p is because gcc will give us an error
568 * if we try to allocate the static variable to fmt if it is not a
569 * constant. Even with the outer if statement optimizing out.
570 */
571 #define event_trace_printk(ip, fmt, args...) \
572 do { \
573 __trace_printk_check_format(fmt, ##args); \
574 tracing_record_cmdline(current); \
575 if (__builtin_constant_p(fmt)) { \
576 static const char *trace_printk_fmt \
577 __attribute__((section("__trace_printk_fmt"))) = \
578 __builtin_constant_p(fmt) ? fmt : NULL; \
579 \
580 __trace_bprintk(ip, trace_printk_fmt, ##args); \
581 } else \
582 __trace_printk(ip, fmt, ##args); \
583 } while (0)
584
585 #ifdef CONFIG_PERF_EVENTS
586 struct perf_event;
587
588 DECLARE_PER_CPU(struct pt_regs, perf_trace_regs);
589
590 extern int perf_trace_init(struct perf_event *event);
591 extern void perf_trace_destroy(struct perf_event *event);
592 extern int perf_trace_add(struct perf_event *event, int flags);
593 extern void perf_trace_del(struct perf_event *event, int flags);
594 extern int ftrace_profile_set_filter(struct perf_event *event, int event_id,
595 char *filter_str);
596 extern void ftrace_profile_free_filter(struct perf_event *event);
597 extern void *perf_trace_buf_prepare(int size, unsigned short type,
598 struct pt_regs *regs, int *rctxp);
599
600 static inline void
601 perf_trace_buf_submit(void *raw_data, int size, int rctx, u64 addr,
602 u64 count, struct pt_regs *regs, void *head,
603 struct task_struct *task)
604 {
605 perf_tp_event(addr, count, raw_data, size, regs, head, rctx, task);
606 }
607 #endif
608
609 #endif /* _LINUX_FTRACE_EVENT_H */
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