1 /* SPDX-License-Identifier: GPL-2.0 */
3 #ifndef _LINUX_TRACE_EVENT_H
4 #define _LINUX_TRACE_EVENT_H
6 #include <linux/ring_buffer.h>
7 #include <linux/trace_seq.h>
8 #include <linux/percpu.h>
9 #include <linux/hardirq.h>
10 #include <linux/perf_event.h>
11 #include <linux/tracepoint.h>
19 const char *trace_print_flags_seq(struct trace_seq
*p
, const char *delim
,
21 const struct trace_print_flags
*flag_array
);
23 const char *trace_print_symbols_seq(struct trace_seq
*p
, unsigned long val
,
24 const struct trace_print_flags
*symbol_array
);
26 #if BITS_PER_LONG == 32
27 const char *trace_print_flags_seq_u64(struct trace_seq
*p
, const char *delim
,
28 unsigned long long flags
,
29 const struct trace_print_flags_u64
*flag_array
);
31 const char *trace_print_symbols_seq_u64(struct trace_seq
*p
,
32 unsigned long long val
,
33 const struct trace_print_flags_u64
37 const char *trace_print_bitmask_seq(struct trace_seq
*p
, void *bitmask_ptr
,
38 unsigned int bitmask_size
);
40 const char *trace_print_hex_seq(struct trace_seq
*p
,
41 const unsigned char *buf
, int len
,
44 const char *trace_print_array_seq(struct trace_seq
*p
,
45 const void *buf
, int count
,
48 struct trace_iterator
;
51 int trace_raw_output_prep(struct trace_iterator
*iter
,
52 struct trace_event
*event
);
55 * The trace entry - the most basic unit of tracing. This is what
56 * is printed in the end as a single line in the trace output, such as:
58 * bash-15816 [01] 235.197585: idle_cpu <- irq_enter
63 unsigned char preempt_count
;
67 #define TRACE_EVENT_TYPE_MAX \
68 ((1 << (sizeof(((struct trace_entry *)0)->type) * 8)) - 1)
71 * Trace iterator - used by printout routines who present trace
72 * results to users and which routines might sleep, etc:
74 struct trace_iterator
{
75 struct trace_array
*tr
;
77 struct trace_buffer
*trace_buffer
;
81 struct ring_buffer_iter
**buffer_iter
;
82 unsigned long iter_flags
;
84 /* trace_seq for __print_flags() and __print_symbolic() etc. */
85 struct trace_seq tmp_seq
;
87 cpumask_var_t started
;
89 /* it's true when current open file is snapshot */
92 /* The below is zeroed out in pipe_read */
94 struct trace_entry
*ent
;
95 unsigned long lost_events
;
104 /* All new field here will be zeroed out in pipe_read */
107 enum trace_iter_flags
{
108 TRACE_FILE_LAT_FMT
= 1,
109 TRACE_FILE_ANNOTATE
= 2,
110 TRACE_FILE_TIME_IN_NS
= 4,
114 typedef enum print_line_t (*trace_print_func
)(struct trace_iterator
*iter
,
115 int flags
, struct trace_event
*event
);
117 struct trace_event_functions
{
118 trace_print_func trace
;
119 trace_print_func raw
;
120 trace_print_func hex
;
121 trace_print_func binary
;
125 struct hlist_node node
;
126 struct list_head list
;
128 struct trace_event_functions
*funcs
;
131 extern int register_trace_event(struct trace_event
*event
);
132 extern int unregister_trace_event(struct trace_event
*event
);
134 /* Return values for print_line callback */
136 TRACE_TYPE_PARTIAL_LINE
= 0, /* Retry after flushing the seq */
137 TRACE_TYPE_HANDLED
= 1,
138 TRACE_TYPE_UNHANDLED
= 2, /* Relay to other output functions */
139 TRACE_TYPE_NO_CONSUME
= 3 /* Handled but ask to not consume */
142 enum print_line_t
trace_handle_return(struct trace_seq
*s
);
144 void tracing_generic_entry_update(struct trace_entry
*entry
,
147 struct trace_event_file
;
149 struct ring_buffer_event
*
150 trace_event_buffer_lock_reserve(struct ring_buffer
**current_buffer
,
151 struct trace_event_file
*trace_file
,
152 int type
, unsigned long len
,
153 unsigned long flags
, int pc
);
155 #define TRACE_RECORD_CMDLINE BIT(0)
156 #define TRACE_RECORD_TGID BIT(1)
158 void tracing_record_taskinfo(struct task_struct
*task
, int flags
);
159 void tracing_record_taskinfo_sched_switch(struct task_struct
*prev
,
160 struct task_struct
*next
, int flags
);
162 void tracing_record_cmdline(struct task_struct
*task
);
163 void tracing_record_tgid(struct task_struct
*task
);
165 int trace_output_call(struct trace_iterator
*iter
, char *name
, char *fmt
, ...);
171 TRACE_REG_UNREGISTER
,
172 #ifdef CONFIG_PERF_EVENTS
173 TRACE_REG_PERF_REGISTER
,
174 TRACE_REG_PERF_UNREGISTER
,
176 TRACE_REG_PERF_CLOSE
,
182 struct trace_event_call
;
184 struct trace_event_class
{
187 #ifdef CONFIG_PERF_EVENTS
190 int (*reg
)(struct trace_event_call
*event
,
191 enum trace_reg type
, void *data
);
192 int (*define_fields
)(struct trace_event_call
*);
193 struct list_head
*(*get_fields
)(struct trace_event_call
*);
194 struct list_head fields
;
195 int (*raw_init
)(struct trace_event_call
*);
198 extern int trace_event_reg(struct trace_event_call
*event
,
199 enum trace_reg type
, void *data
);
201 struct trace_event_buffer
{
202 struct ring_buffer
*buffer
;
203 struct ring_buffer_event
*event
;
204 struct trace_event_file
*trace_file
;
210 void *trace_event_buffer_reserve(struct trace_event_buffer
*fbuffer
,
211 struct trace_event_file
*trace_file
,
214 void trace_event_buffer_commit(struct trace_event_buffer
*fbuffer
);
217 TRACE_EVENT_FL_FILTERED_BIT
,
218 TRACE_EVENT_FL_CAP_ANY_BIT
,
219 TRACE_EVENT_FL_NO_SET_FILTER_BIT
,
220 TRACE_EVENT_FL_IGNORE_ENABLE_BIT
,
221 TRACE_EVENT_FL_TRACEPOINT_BIT
,
222 TRACE_EVENT_FL_KPROBE_BIT
,
223 TRACE_EVENT_FL_UPROBE_BIT
,
228 * FILTERED - The event has a filter attached
229 * CAP_ANY - Any user can enable for perf
230 * NO_SET_FILTER - Set when filter has error and is to be ignored
231 * IGNORE_ENABLE - For trace internal events, do not enable with debugfs file
232 * TRACEPOINT - Event is a tracepoint
233 * KPROBE - Event is a kprobe
234 * UPROBE - Event is a uprobe
237 TRACE_EVENT_FL_FILTERED
= (1 << TRACE_EVENT_FL_FILTERED_BIT
),
238 TRACE_EVENT_FL_CAP_ANY
= (1 << TRACE_EVENT_FL_CAP_ANY_BIT
),
239 TRACE_EVENT_FL_NO_SET_FILTER
= (1 << TRACE_EVENT_FL_NO_SET_FILTER_BIT
),
240 TRACE_EVENT_FL_IGNORE_ENABLE
= (1 << TRACE_EVENT_FL_IGNORE_ENABLE_BIT
),
241 TRACE_EVENT_FL_TRACEPOINT
= (1 << TRACE_EVENT_FL_TRACEPOINT_BIT
),
242 TRACE_EVENT_FL_KPROBE
= (1 << TRACE_EVENT_FL_KPROBE_BIT
),
243 TRACE_EVENT_FL_UPROBE
= (1 << TRACE_EVENT_FL_UPROBE_BIT
),
246 #define TRACE_EVENT_FL_UKPROBE (TRACE_EVENT_FL_KPROBE | TRACE_EVENT_FL_UPROBE)
248 struct trace_event_call
{
249 struct list_head list
;
250 struct trace_event_class
*class;
253 /* Set TRACE_EVENT_FL_TRACEPOINT flag when using "tp" */
254 struct tracepoint
*tp
;
256 struct trace_event event
;
258 struct event_filter
*filter
;
262 * bit 0: filter_active
263 * bit 1: allow trace by non root (cap any)
264 * bit 2: failed to apply filter
265 * bit 3: trace internal event (do not enable)
266 * bit 4: Event was enabled by module
267 * bit 5: use call filter rather than file filter
268 * bit 6: Event is a tracepoint
270 int flags
; /* static flags of different events */
272 #ifdef CONFIG_PERF_EVENTS
274 struct hlist_head __percpu
*perf_events
;
275 struct bpf_prog_array __rcu
*prog_array
;
277 int (*perf_perm
)(struct trace_event_call
*,
278 struct perf_event
*);
282 #ifdef CONFIG_PERF_EVENTS
283 static inline bool bpf_prog_array_valid(struct trace_event_call
*call
)
286 * This inline function checks whether call->prog_array
287 * is valid or not. The function is called in various places,
288 * outside rcu_read_lock/unlock, as a heuristic to speed up execution.
290 * If this function returns true, and later call->prog_array
291 * becomes false inside rcu_read_lock/unlock region,
292 * we bail out then. If this function return false,
293 * there is a risk that we might miss a few events if the checking
294 * were delayed until inside rcu_read_lock/unlock region and
295 * call->prog_array happened to become non-NULL then.
297 * Here, READ_ONCE() is used instead of rcu_access_pointer().
298 * rcu_access_pointer() requires the actual definition of
299 * "struct bpf_prog_array" while READ_ONCE() only needs
300 * a declaration of the same type.
302 return !!READ_ONCE(call
->prog_array
);
306 static inline const char *
307 trace_event_name(struct trace_event_call
*call
)
309 if (call
->flags
& TRACE_EVENT_FL_TRACEPOINT
)
310 return call
->tp
? call
->tp
->name
: NULL
;
316 struct trace_subsystem_dir
;
319 EVENT_FILE_FL_ENABLED_BIT
,
320 EVENT_FILE_FL_RECORDED_CMD_BIT
,
321 EVENT_FILE_FL_RECORDED_TGID_BIT
,
322 EVENT_FILE_FL_FILTERED_BIT
,
323 EVENT_FILE_FL_NO_SET_FILTER_BIT
,
324 EVENT_FILE_FL_SOFT_MODE_BIT
,
325 EVENT_FILE_FL_SOFT_DISABLED_BIT
,
326 EVENT_FILE_FL_TRIGGER_MODE_BIT
,
327 EVENT_FILE_FL_TRIGGER_COND_BIT
,
328 EVENT_FILE_FL_PID_FILTER_BIT
,
329 EVENT_FILE_FL_WAS_ENABLED_BIT
,
334 * ENABLED - The event is enabled
335 * RECORDED_CMD - The comms should be recorded at sched_switch
336 * RECORDED_TGID - The tgids should be recorded at sched_switch
337 * FILTERED - The event has a filter attached
338 * NO_SET_FILTER - Set when filter has error and is to be ignored
339 * SOFT_MODE - The event is enabled/disabled by SOFT_DISABLED
340 * SOFT_DISABLED - When set, do not trace the event (even though its
341 * tracepoint may be enabled)
342 * TRIGGER_MODE - When set, invoke the triggers associated with the event
343 * TRIGGER_COND - When set, one or more triggers has an associated filter
344 * PID_FILTER - When set, the event is filtered based on pid
345 * WAS_ENABLED - Set when enabled to know to clear trace on module removal
348 EVENT_FILE_FL_ENABLED
= (1 << EVENT_FILE_FL_ENABLED_BIT
),
349 EVENT_FILE_FL_RECORDED_CMD
= (1 << EVENT_FILE_FL_RECORDED_CMD_BIT
),
350 EVENT_FILE_FL_RECORDED_TGID
= (1 << EVENT_FILE_FL_RECORDED_TGID_BIT
),
351 EVENT_FILE_FL_FILTERED
= (1 << EVENT_FILE_FL_FILTERED_BIT
),
352 EVENT_FILE_FL_NO_SET_FILTER
= (1 << EVENT_FILE_FL_NO_SET_FILTER_BIT
),
353 EVENT_FILE_FL_SOFT_MODE
= (1 << EVENT_FILE_FL_SOFT_MODE_BIT
),
354 EVENT_FILE_FL_SOFT_DISABLED
= (1 << EVENT_FILE_FL_SOFT_DISABLED_BIT
),
355 EVENT_FILE_FL_TRIGGER_MODE
= (1 << EVENT_FILE_FL_TRIGGER_MODE_BIT
),
356 EVENT_FILE_FL_TRIGGER_COND
= (1 << EVENT_FILE_FL_TRIGGER_COND_BIT
),
357 EVENT_FILE_FL_PID_FILTER
= (1 << EVENT_FILE_FL_PID_FILTER_BIT
),
358 EVENT_FILE_FL_WAS_ENABLED
= (1 << EVENT_FILE_FL_WAS_ENABLED_BIT
),
361 struct trace_event_file
{
362 struct list_head list
;
363 struct trace_event_call
*event_call
;
364 struct event_filter __rcu
*filter
;
366 struct trace_array
*tr
;
367 struct trace_subsystem_dir
*system
;
368 struct list_head triggers
;
373 * bit 1: enabled cmd record
374 * bit 2: enable/disable with the soft disable bit
375 * bit 3: soft disabled
376 * bit 4: trigger enabled
378 * Note: The bits must be set atomically to prevent races
379 * from other writers. Reads of flags do not need to be in
380 * sync as they occur in critical sections. But the way flags
381 * is currently used, these changes do not affect the code
382 * except that when a change is made, it may have a slight
383 * delay in propagating the changes to other CPUs due to
384 * caching and such. Which is mostly OK ;-)
387 atomic_t sm_ref
; /* soft-mode reference counter */
388 atomic_t tm_ref
; /* trigger-mode reference counter */
391 #define __TRACE_EVENT_FLAGS(name, value) \
392 static int __init trace_init_flags_##name(void) \
394 event_##name.flags |= value; \
397 early_initcall(trace_init_flags_##name);
399 #define __TRACE_EVENT_PERF_PERM(name, expr...) \
400 static int perf_perm_##name(struct trace_event_call *tp_event, \
401 struct perf_event *p_event) \
403 return ({ expr; }); \
405 static int __init trace_init_perf_perm_##name(void) \
407 event_##name.perf_perm = &perf_perm_##name; \
410 early_initcall(trace_init_perf_perm_##name);
412 #define PERF_MAX_TRACE_SIZE 2048
414 #define MAX_FILTER_STR_VAL 256 /* Should handle KSYM_SYMBOL_LEN */
416 enum event_trigger_type
{
418 ETT_TRACE_ONOFF
= (1 << 0),
419 ETT_SNAPSHOT
= (1 << 1),
420 ETT_STACKTRACE
= (1 << 2),
421 ETT_EVENT_ENABLE
= (1 << 3),
422 ETT_EVENT_HIST
= (1 << 4),
423 ETT_HIST_ENABLE
= (1 << 5),
426 extern int filter_match_preds(struct event_filter
*filter
, void *rec
);
428 extern enum event_trigger_type
event_triggers_call(struct trace_event_file
*file
,
430 extern void event_triggers_post_call(struct trace_event_file
*file
,
431 enum event_trigger_type tt
,
434 bool trace_event_ignore_this_pid(struct trace_event_file
*trace_file
);
437 * trace_trigger_soft_disabled - do triggers and test if soft disabled
438 * @file: The file pointer of the event to test
440 * If any triggers without filters are attached to this event, they
441 * will be called here. If the event is soft disabled and has no
442 * triggers that require testing the fields, it will return true,
446 trace_trigger_soft_disabled(struct trace_event_file
*file
)
448 unsigned long eflags
= file
->flags
;
450 if (!(eflags
& EVENT_FILE_FL_TRIGGER_COND
)) {
451 if (eflags
& EVENT_FILE_FL_TRIGGER_MODE
)
452 event_triggers_call(file
, NULL
);
453 if (eflags
& EVENT_FILE_FL_SOFT_DISABLED
)
455 if (eflags
& EVENT_FILE_FL_PID_FILTER
)
456 return trace_event_ignore_this_pid(file
);
461 #ifdef CONFIG_BPF_EVENTS
462 unsigned int trace_call_bpf(struct trace_event_call
*call
, void *ctx
);
463 int perf_event_attach_bpf_prog(struct perf_event
*event
, struct bpf_prog
*prog
);
464 void perf_event_detach_bpf_prog(struct perf_event
*event
);
466 static inline unsigned int trace_call_bpf(struct trace_event_call
*call
, void *ctx
)
472 perf_event_attach_bpf_prog(struct perf_event
*event
, struct bpf_prog
*prog
)
477 static inline void perf_event_detach_bpf_prog(struct perf_event
*event
) { }
483 FILTER_STATIC_STRING
,
491 extern int trace_event_raw_init(struct trace_event_call
*call
);
492 extern int trace_define_field(struct trace_event_call
*call
, const char *type
,
493 const char *name
, int offset
, int size
,
494 int is_signed
, int filter_type
);
495 extern int trace_add_event_call(struct trace_event_call
*call
);
496 extern int trace_remove_event_call(struct trace_event_call
*call
);
497 extern int trace_event_get_offsets(struct trace_event_call
*call
);
499 #define is_signed_type(type) (((type)(-1)) < (type)1)
501 int trace_set_clr_event(const char *system
, const char *event
, int set
);
504 * The double __builtin_constant_p is because gcc will give us an error
505 * if we try to allocate the static variable to fmt if it is not a
506 * constant. Even with the outer if statement optimizing out.
508 #define event_trace_printk(ip, fmt, args...) \
510 __trace_printk_check_format(fmt, ##args); \
511 tracing_record_cmdline(current); \
512 if (__builtin_constant_p(fmt)) { \
513 static const char *trace_printk_fmt \
514 __attribute__((section("__trace_printk_fmt"))) = \
515 __builtin_constant_p(fmt) ? fmt : NULL; \
517 __trace_bprintk(ip, trace_printk_fmt, ##args); \
519 __trace_printk(ip, fmt, ##args); \
522 #ifdef CONFIG_PERF_EVENTS
525 DECLARE_PER_CPU(struct pt_regs
, perf_trace_regs
);
527 extern int perf_trace_init(struct perf_event
*event
);
528 extern void perf_trace_destroy(struct perf_event
*event
);
529 extern int perf_trace_add(struct perf_event
*event
, int flags
);
530 extern void perf_trace_del(struct perf_event
*event
, int flags
);
531 extern int ftrace_profile_set_filter(struct perf_event
*event
, int event_id
,
533 extern void ftrace_profile_free_filter(struct perf_event
*event
);
534 void perf_trace_buf_update(void *record
, u16 type
);
535 void *perf_trace_buf_alloc(int size
, struct pt_regs
**regs
, int *rctxp
);
537 void perf_trace_run_bpf_submit(void *raw_data
, int size
, int rctx
,
538 struct trace_event_call
*call
, u64 count
,
539 struct pt_regs
*regs
, struct hlist_head
*head
,
540 struct task_struct
*task
);
543 perf_trace_buf_submit(void *raw_data
, int size
, int rctx
, u16 type
,
544 u64 count
, struct pt_regs
*regs
, void *head
,
545 struct task_struct
*task
, struct perf_event
*event
)
547 perf_tp_event(type
, count
, raw_data
, size
, regs
, head
, rctx
, task
, event
);
552 #endif /* _LINUX_TRACE_EVENT_H */