Merge tag 'linux-kselftest-4.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel...
[sfrench/cifs-2.6.git] / include / linux / trace_events.h
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_array __rcu     *prog_array;
276
277         int     (*perf_perm)(struct trace_event_call *,
278                              struct perf_event *);
279 #endif
280 };
281
282 #ifdef CONFIG_PERF_EVENTS
283 static inline bool bpf_prog_array_valid(struct trace_event_call *call)
284 {
285         /*
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.
289          *
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.
296          *
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.
301          */
302         return !!READ_ONCE(call->prog_array);
303 }
304 #endif
305
306 static inline const char *
307 trace_event_name(struct trace_event_call *call)
308 {
309         if (call->flags & TRACE_EVENT_FL_TRACEPOINT)
310                 return call->tp ? call->tp->name : NULL;
311         else
312                 return call->name;
313 }
314
315 struct trace_array;
316 struct trace_subsystem_dir;
317
318 enum {
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,
330 };
331
332 /*
333  * Event file flags:
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
346  */
347 enum {
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),
359 };
360
361 struct trace_event_file {
362         struct list_head                list;
363         struct trace_event_call         *event_call;
364         struct event_filter __rcu       *filter;
365         struct dentry                   *dir;
366         struct trace_array              *tr;
367         struct trace_subsystem_dir      *system;
368         struct list_head                triggers;
369
370         /*
371          * 32 bit flags:
372          *   bit 0:             enabled
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
377          *
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 ;-)
385          */
386         unsigned long           flags;
387         atomic_t                sm_ref; /* soft-mode reference counter */
388         atomic_t                tm_ref; /* trigger-mode reference counter */
389 };
390
391 #define __TRACE_EVENT_FLAGS(name, value)                                \
392         static int __init trace_init_flags_##name(void)                 \
393         {                                                               \
394                 event_##name.flags |= value;                            \
395                 return 0;                                               \
396         }                                                               \
397         early_initcall(trace_init_flags_##name);
398
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)         \
402         {                                                               \
403                 return ({ expr; });                                     \
404         }                                                               \
405         static int __init trace_init_perf_perm_##name(void)             \
406         {                                                               \
407                 event_##name.perf_perm = &perf_perm_##name;             \
408                 return 0;                                               \
409         }                                                               \
410         early_initcall(trace_init_perf_perm_##name);
411
412 #define PERF_MAX_TRACE_SIZE     2048
413
414 #define MAX_FILTER_STR_VAL      256     /* Should handle KSYM_SYMBOL_LEN */
415
416 enum event_trigger_type {
417         ETT_NONE                = (0),
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),
424 };
425
426 extern int filter_match_preds(struct event_filter *filter, void *rec);
427
428 extern enum event_trigger_type event_triggers_call(struct trace_event_file *file,
429                                                    void *rec);
430 extern void event_triggers_post_call(struct trace_event_file *file,
431                                      enum event_trigger_type tt,
432                                      void *rec);
433
434 bool trace_event_ignore_this_pid(struct trace_event_file *trace_file);
435
436 /**
437  * trace_trigger_soft_disabled - do triggers and test if soft disabled
438  * @file: The file pointer of the event to test
439  *
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,
443  * otherwise false.
444  */
445 static inline bool
446 trace_trigger_soft_disabled(struct trace_event_file *file)
447 {
448         unsigned long eflags = file->flags;
449
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)
454                         return true;
455                 if (eflags & EVENT_FILE_FL_PID_FILTER)
456                         return trace_event_ignore_this_pid(file);
457         }
458         return false;
459 }
460
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);
465 #else
466 static inline unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx)
467 {
468         return 1;
469 }
470
471 static inline int
472 perf_event_attach_bpf_prog(struct perf_event *event, struct bpf_prog *prog)
473 {
474         return -EOPNOTSUPP;
475 }
476
477 static inline void perf_event_detach_bpf_prog(struct perf_event *event) { }
478
479 #endif
480
481 enum {
482         FILTER_OTHER = 0,
483         FILTER_STATIC_STRING,
484         FILTER_DYN_STRING,
485         FILTER_PTR_STRING,
486         FILTER_TRACE_FN,
487         FILTER_COMM,
488         FILTER_CPU,
489 };
490
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);
498
499 #define is_signed_type(type)    (((type)(-1)) < (type)1)
500
501 int trace_set_clr_event(const char *system, const char *event, int set);
502
503 /*
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.
507  */
508 #define event_trace_printk(ip, fmt, args...)                            \
509 do {                                                                    \
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;         \
516                                                                         \
517                 __trace_bprintk(ip, trace_printk_fmt, ##args);          \
518         } else                                                          \
519                 __trace_printk(ip, fmt, ##args);                        \
520 } while (0)
521
522 #ifdef CONFIG_PERF_EVENTS
523 struct perf_event;
524
525 DECLARE_PER_CPU(struct pt_regs, perf_trace_regs);
526
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,
532                                      char *filter_str);
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);
536
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);
541
542 static inline void
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)
546 {
547         perf_tp_event(type, count, raw_data, size, regs, head, rctx, task, event);
548 }
549
550 #endif
551
552 #endif /* _LINUX_TRACE_EVENT_H */