1 /* SPDX-License-Identifier: GPL-2.0 */
2
3 #ifndef _LINUX_TRACE_EVENT_H
4 #define _LINUX_TRACE_EVENT_H
5
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>
12
13 struct trace_array;
14 struct trace_buffer;
15 struct tracer;
16 struct dentry;
17 struct bpf_prog;
18
19 const char *trace_print_flags_seq(struct trace_seq *p, const char *delim,
20 unsigned long flags,
21 const struct trace_print_flags *flag_array);
22
23 const char *trace_print_symbols_seq(struct trace_seq *p, unsigned long val,
24 const struct trace_print_flags *symbol_array);
25
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);
30
31 const char *trace_print_symbols_seq_u64(struct trace_seq *p,
32 unsigned long long val,
33 const struct trace_print_flags_u64
34 *symbol_array);
35 #endif
36
37 const char *trace_print_bitmask_seq(struct trace_seq *p, void *bitmask_ptr,
38 unsigned int bitmask_size);
39
40 const char *trace_print_hex_seq(struct trace_seq *p,
41 const unsigned char *buf, int len,
42 bool concatenate);
43
44 const char *trace_print_array_seq(struct trace_seq *p,
45 const void *buf, int count,
46 size_t el_size);
47
48 struct trace_iterator;
49 struct trace_event;
50
51 int trace_raw_output_prep(struct trace_iterator *iter,
52 struct trace_event *event);
53
54 /*
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:
57 *
58 * bash-15816 [01] 235.197585: idle_cpu <- irq_enter
59 */
60 struct trace_entry {
61 unsigned short type;
62 unsigned char flags;
63 unsigned char preempt_count;
64 int pid;
65 };
66
67 #define TRACE_EVENT_TYPE_MAX \
68 ((1 << (sizeof(((struct trace_entry *)0)->type) * 8)) - 1)
69
70 /*
71 * Trace iterator - used by printout routines who present trace
72 * results to users and which routines might sleep, etc:
73 */
74 struct trace_iterator {
75 struct trace_array *tr;
76 struct tracer *trace;
77 struct trace_buffer *trace_buffer;
78 void *private;
79 int cpu_file;
80 struct mutex mutex;
81 struct ring_buffer_iter **buffer_iter;
82 unsigned long iter_flags;
83
84 /* trace_seq for __print_flags() and __print_symbolic() etc. */
85 struct trace_seq tmp_seq;
86
87 cpumask_var_t started;
88
89 /* it's true when current open file is snapshot */
90 bool snapshot;
91
92 /* The below is zeroed out in pipe_read */
93 struct trace_seq seq;
94 struct trace_entry *ent;
95 unsigned long lost_events;
96 int leftover;
97 int ent_size;
98 int cpu;
99 u64 ts;
100
101 loff_t pos;
102 long idx;
103
104 /* All new field here will be zeroed out in pipe_read */
105 };
106
107 enum trace_iter_flags {
108 TRACE_FILE_LAT_FMT = 1,
109 TRACE_FILE_ANNOTATE = 2,
110 TRACE_FILE_TIME_IN_NS = 4,
111 };
112
113
114 typedef enum print_line_t (*trace_print_func)(struct trace_iterator *iter,
115 int flags, struct trace_event *event);
116
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;
122 };
123
124 struct trace_event {
125 struct hlist_node node;
126 struct list_head list;
127 int type;
128 struct trace_event_functions *funcs;
129 };
130
131 extern int register_trace_event(struct trace_event *event);
132 extern int unregister_trace_event(struct trace_event *event);
133
134 /* Return values for print_line callback */
135 enum print_line_t {
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 */
140 };
141
142 enum print_line_t trace_handle_return(struct trace_seq *s);
143
144 void tracing_generic_entry_update(struct trace_entry *entry,
145 unsigned long flags,
146 int pc);
147 struct trace_event_file;
148
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);
154
155 #define TRACE_RECORD_CMDLINE BIT(0)
156 #define TRACE_RECORD_TGID BIT(1)
157
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);
161
162 void tracing_record_cmdline(struct task_struct *task);
163 void tracing_record_tgid(struct task_struct *task);
164
165 int trace_output_call(struct trace_iterator *iter, char *name, char *fmt, ...);
166
167 struct event_filter;
168
169 enum trace_reg {
170 TRACE_REG_REGISTER,
171 TRACE_REG_UNREGISTER,
172 #ifdef CONFIG_PERF_EVENTS
173 TRACE_REG_PERF_REGISTER,
174 TRACE_REG_PERF_UNREGISTER,
175 TRACE_REG_PERF_OPEN,
176 TRACE_REG_PERF_CLOSE,
177 TRACE_REG_PERF_ADD,
178 TRACE_REG_PERF_DEL,
179 #endif
180 };
181
182 struct trace_event_call;
183
184 struct trace_event_class {
185 const char *system;
186 void *probe;
187 #ifdef CONFIG_PERF_EVENTS
188 void *perf_probe;
189 #endif
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 *);
196 };
197
198 extern int trace_event_reg(struct trace_event_call *event,
199 enum trace_reg type, void *data);
200
201 struct trace_event_buffer {
202 struct ring_buffer *buffer;
203 struct ring_buffer_event *event;
204 struct trace_event_file *trace_file;
205 void *entry;
206 unsigned long flags;
207 int pc;
208 };
209
210 void *trace_event_buffer_reserve(struct trace_event_buffer *fbuffer,
211 struct trace_event_file *trace_file,
212 unsigned long len);
213
214 void trace_event_buffer_commit(struct trace_event_buffer *fbuffer);
215
216 enum {
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,
224 };
225
226 /*
227 * Event flags:
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
235 */
236 enum {
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),
244 };
245
246 #define TRACE_EVENT_FL_UKPROBE (TRACE_EVENT_FL_KPROBE | TRACE_EVENT_FL_UPROBE)
247
248 struct trace_event_call {
249 struct list_head list;
250 struct trace_event_class *class;
251 union {
252 char *name;
253 /* Set TRACE_EVENT_FL_TRACEPOINT flag when using "tp" */
254 struct tracepoint *tp;
255 };
256 struct trace_event event;
257 char *print_fmt;
258 struct event_filter *filter;
259 void *mod;
260 void *data;
261 /*
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
269 */
270 int flags; /* static flags of different events */
271
272 #ifdef CONFIG_PERF_EVENTS
273 int perf_refcount;
274 struct hlist_head __percpu *perf_events;
275 struct bpf_prog *prog;
276 struct perf_event *bpf_prog_owner;
277
278 int (*perf_perm)(struct trace_event_call *,
279 struct perf_event *);
280 #endif
281 };
282
283 static inline const char *
trace_event_name(struct trace_event_call * call)284 trace_event_name(struct trace_event_call *call)
285 {
286 if (call->flags & TRACE_EVENT_FL_TRACEPOINT)
287 return call->tp ? call->tp->name : NULL;
288 else
289 return call->name;
290 }
291
292 struct trace_array;
293 struct trace_subsystem_dir;
294
295 enum {
296 EVENT_FILE_FL_ENABLED_BIT,
297 EVENT_FILE_FL_RECORDED_CMD_BIT,
298 EVENT_FILE_FL_RECORDED_TGID_BIT,
299 EVENT_FILE_FL_FILTERED_BIT,
300 EVENT_FILE_FL_NO_SET_FILTER_BIT,
301 EVENT_FILE_FL_SOFT_MODE_BIT,
302 EVENT_FILE_FL_SOFT_DISABLED_BIT,
303 EVENT_FILE_FL_TRIGGER_MODE_BIT,
304 EVENT_FILE_FL_TRIGGER_COND_BIT,
305 EVENT_FILE_FL_PID_FILTER_BIT,
306 EVENT_FILE_FL_WAS_ENABLED_BIT,
307 };
308
309 /*
310 * Event file flags:
311 * ENABLED - The event is enabled
312 * RECORDED_CMD - The comms should be recorded at sched_switch
313 * RECORDED_TGID - The tgids should be recorded at sched_switch
314 * FILTERED - The event has a filter attached
315 * NO_SET_FILTER - Set when filter has error and is to be ignored
316 * SOFT_MODE - The event is enabled/disabled by SOFT_DISABLED
317 * SOFT_DISABLED - When set, do not trace the event (even though its
318 * tracepoint may be enabled)
319 * TRIGGER_MODE - When set, invoke the triggers associated with the event
320 * TRIGGER_COND - When set, one or more triggers has an associated filter
321 * PID_FILTER - When set, the event is filtered based on pid
322 * WAS_ENABLED - Set when enabled to know to clear trace on module removal
323 */
324 enum {
325 EVENT_FILE_FL_ENABLED = (1 << EVENT_FILE_FL_ENABLED_BIT),
326 EVENT_FILE_FL_RECORDED_CMD = (1 << EVENT_FILE_FL_RECORDED_CMD_BIT),
327 EVENT_FILE_FL_RECORDED_TGID = (1 << EVENT_FILE_FL_RECORDED_TGID_BIT),
328 EVENT_FILE_FL_FILTERED = (1 << EVENT_FILE_FL_FILTERED_BIT),
329 EVENT_FILE_FL_NO_SET_FILTER = (1 << EVENT_FILE_FL_NO_SET_FILTER_BIT),
330 EVENT_FILE_FL_SOFT_MODE = (1 << EVENT_FILE_FL_SOFT_MODE_BIT),
331 EVENT_FILE_FL_SOFT_DISABLED = (1 << EVENT_FILE_FL_SOFT_DISABLED_BIT),
332 EVENT_FILE_FL_TRIGGER_MODE = (1 << EVENT_FILE_FL_TRIGGER_MODE_BIT),
333 EVENT_FILE_FL_TRIGGER_COND = (1 << EVENT_FILE_FL_TRIGGER_COND_BIT),
334 EVENT_FILE_FL_PID_FILTER = (1 << EVENT_FILE_FL_PID_FILTER_BIT),
335 EVENT_FILE_FL_WAS_ENABLED = (1 << EVENT_FILE_FL_WAS_ENABLED_BIT),
336 };
337
338 struct trace_event_file {
339 struct list_head list;
340 struct trace_event_call *event_call;
341 struct event_filter __rcu *filter;
342 struct dentry *dir;
343 struct trace_array *tr;
344 struct trace_subsystem_dir *system;
345 struct list_head triggers;
346
347 /*
348 * 32 bit flags:
349 * bit 0: enabled
350 * bit 1: enabled cmd record
351 * bit 2: enable/disable with the soft disable bit
352 * bit 3: soft disabled
353 * bit 4: trigger enabled
354 *
355 * Note: The bits must be set atomically to prevent races
356 * from other writers. Reads of flags do not need to be in
357 * sync as they occur in critical sections. But the way flags
358 * is currently used, these changes do not affect the code
359 * except that when a change is made, it may have a slight
360 * delay in propagating the changes to other CPUs due to
361 * caching and such. Which is mostly OK ;-)
362 */
363 unsigned long flags;
364 atomic_t sm_ref; /* soft-mode reference counter */
365 atomic_t tm_ref; /* trigger-mode reference counter */
366 };
367
368 #define __TRACE_EVENT_FLAGS(name, value) \
369 static int __init trace_init_flags_##name(void) \
370 { \
371 event_##name.flags |= value; \
372 return 0; \
373 } \
374 early_initcall(trace_init_flags_##name);
375
376 #define __TRACE_EVENT_PERF_PERM(name, expr...) \
377 static int perf_perm_##name(struct trace_event_call *tp_event, \
378 struct perf_event *p_event) \
379 { \
380 return ({ expr; }); \
381 } \
382 static int __init trace_init_perf_perm_##name(void) \
383 { \
384 event_##name.perf_perm = &perf_perm_##name; \
385 return 0; \
386 } \
387 early_initcall(trace_init_perf_perm_##name);
388
389 #define PERF_MAX_TRACE_SIZE 2048
390
391 #define MAX_FILTER_STR_VAL 256 /* Should handle KSYM_SYMBOL_LEN */
392
393 enum event_trigger_type {
394 ETT_NONE = (0),
395 ETT_TRACE_ONOFF = (1 << 0),
396 ETT_SNAPSHOT = (1 << 1),
397 ETT_STACKTRACE = (1 << 2),
398 ETT_EVENT_ENABLE = (1 << 3),
399 ETT_EVENT_HIST = (1 << 4),
400 ETT_HIST_ENABLE = (1 << 5),
401 };
402
403 extern int filter_match_preds(struct event_filter *filter, void *rec);
404
405 extern enum event_trigger_type event_triggers_call(struct trace_event_file *file,
406 void *rec);
407 extern void event_triggers_post_call(struct trace_event_file *file,
408 enum event_trigger_type tt,
409 void *rec);
410
411 bool trace_event_ignore_this_pid(struct trace_event_file *trace_file);
412
413 /**
414 * trace_trigger_soft_disabled - do triggers and test if soft disabled
415 * @file: The file pointer of the event to test
416 *
417 * If any triggers without filters are attached to this event, they
418 * will be called here. If the event is soft disabled and has no
419 * triggers that require testing the fields, it will return true,
420 * otherwise false.
421 */
422 static inline bool
trace_trigger_soft_disabled(struct trace_event_file * file)423 trace_trigger_soft_disabled(struct trace_event_file *file)
424 {
425 unsigned long eflags = file->flags;
426
427 if (!(eflags & EVENT_FILE_FL_TRIGGER_COND)) {
428 if (eflags & EVENT_FILE_FL_TRIGGER_MODE)
429 event_triggers_call(file, NULL);
430 if (eflags & EVENT_FILE_FL_SOFT_DISABLED)
431 return true;
432 if (eflags & EVENT_FILE_FL_PID_FILTER)
433 return trace_event_ignore_this_pid(file);
434 }
435 return false;
436 }
437
438 #ifdef CONFIG_BPF_EVENTS
439 unsigned int trace_call_bpf(struct bpf_prog *prog, void *ctx);
440 #else
trace_call_bpf(struct bpf_prog * prog,void * ctx)441 static inline unsigned int trace_call_bpf(struct bpf_prog *prog, void *ctx)
442 {
443 return 1;
444 }
445 #endif
446
447 enum {
448 FILTER_OTHER = 0,
449 FILTER_STATIC_STRING,
450 FILTER_DYN_STRING,
451 FILTER_PTR_STRING,
452 FILTER_TRACE_FN,
453 FILTER_COMM,
454 FILTER_CPU,
455 };
456
457 extern int trace_event_raw_init(struct trace_event_call *call);
458 extern int trace_define_field(struct trace_event_call *call, const char *type,
459 const char *name, int offset, int size,
460 int is_signed, int filter_type);
461 extern int trace_add_event_call(struct trace_event_call *call);
462 extern int trace_remove_event_call(struct trace_event_call *call);
463 extern int trace_event_get_offsets(struct trace_event_call *call);
464
465 #define is_signed_type(type) (((type)(-1)) < (type)1)
466
467 int trace_set_clr_event(const char *system, const char *event, int set);
468
469 /*
470 * The double __builtin_constant_p is because gcc will give us an error
471 * if we try to allocate the static variable to fmt if it is not a
472 * constant. Even with the outer if statement optimizing out.
473 */
474 #define event_trace_printk(ip, fmt, args...) \
475 do { \
476 __trace_printk_check_format(fmt, ##args); \
477 tracing_record_cmdline(current); \
478 if (__builtin_constant_p(fmt)) { \
479 static const char *trace_printk_fmt \
480 __attribute__((section("__trace_printk_fmt"))) = \
481 __builtin_constant_p(fmt) ? fmt : NULL; \
482 \
483 __trace_bprintk(ip, trace_printk_fmt, ##args); \
484 } else \
485 __trace_printk(ip, fmt, ##args); \
486 } while (0)
487
488 #ifdef CONFIG_PERF_EVENTS
489 struct perf_event;
490
491 DECLARE_PER_CPU(struct pt_regs, perf_trace_regs);
492
493 extern int perf_trace_init(struct perf_event *event);
494 extern void perf_trace_destroy(struct perf_event *event);
495 extern int perf_trace_add(struct perf_event *event, int flags);
496 extern void perf_trace_del(struct perf_event *event, int flags);
497 extern int ftrace_profile_set_filter(struct perf_event *event, int event_id,
498 char *filter_str);
499 extern void ftrace_profile_free_filter(struct perf_event *event);
500 void perf_trace_buf_update(void *record, u16 type);
501 void *perf_trace_buf_alloc(int size, struct pt_regs **regs, int *rctxp);
502
503 void perf_trace_run_bpf_submit(void *raw_data, int size, int rctx,
504 struct trace_event_call *call, u64 count,
505 struct pt_regs *regs, struct hlist_head *head,
506 struct task_struct *task);
507
508 static inline void
perf_trace_buf_submit(void * raw_data,int size,int rctx,u16 type,u64 count,struct pt_regs * regs,void * head,struct task_struct * task,struct perf_event * event)509 perf_trace_buf_submit(void *raw_data, int size, int rctx, u16 type,
510 u64 count, struct pt_regs *regs, void *head,
511 struct task_struct *task, struct perf_event *event)
512 {
513 perf_tp_event(type, count, raw_data, size, regs, head, rctx, task, event);
514 }
515 #endif
516
517 #endif /* _LINUX_TRACE_EVENT_H */
518