xref: /linux/kernel/trace/trace.h (revision 0dd9ac63ce26ec87b080ca9c3e6efed33c23ace6)
1 #ifndef _LINUX_KERNEL_TRACE_H
2 #define _LINUX_KERNEL_TRACE_H
3 
4 #include <linux/fs.h>
5 #include <asm/atomic.h>
6 #include <linux/sched.h>
7 #include <linux/clocksource.h>
8 #include <linux/ring_buffer.h>
9 #include <linux/mmiotrace.h>
10 #include <linux/tracepoint.h>
11 #include <linux/ftrace.h>
12 #include <linux/hw_breakpoint.h>
13 #include <linux/trace_seq.h>
14 #include <linux/ftrace_event.h>
15 
16 enum trace_type {
17 	__TRACE_FIRST_TYPE = 0,
18 
19 	TRACE_FN,
20 	TRACE_CTX,
21 	TRACE_WAKE,
22 	TRACE_STACK,
23 	TRACE_PRINT,
24 	TRACE_BPRINT,
25 	TRACE_SPECIAL,
26 	TRACE_MMIO_RW,
27 	TRACE_MMIO_MAP,
28 	TRACE_BRANCH,
29 	TRACE_GRAPH_RET,
30 	TRACE_GRAPH_ENT,
31 	TRACE_USER_STACK,
32 	TRACE_BLK,
33 	TRACE_KSYM,
34 
35 	__TRACE_LAST_TYPE,
36 };
37 
38 
39 #undef __field
40 #define __field(type, item)		type	item;
41 
42 #undef __field_struct
43 #define __field_struct(type, item)	__field(type, item)
44 
45 #undef __field_desc
46 #define __field_desc(type, container, item)
47 
48 #undef __array
49 #define __array(type, item, size)	type	item[size];
50 
51 #undef __array_desc
52 #define __array_desc(type, container, item, size)
53 
54 #undef __dynamic_array
55 #define __dynamic_array(type, item)	type	item[];
56 
57 #undef F_STRUCT
58 #define F_STRUCT(args...)		args
59 
60 #undef FTRACE_ENTRY
61 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print)	\
62 	struct struct_name {					\
63 		struct trace_entry	ent;			\
64 		tstruct						\
65 	}
66 
67 #undef TP_ARGS
68 #define TP_ARGS(args...)	args
69 
70 #undef FTRACE_ENTRY_DUP
71 #define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk)
72 
73 #include "trace_entries.h"
74 
75 /*
76  * syscalls are special, and need special handling, this is why
77  * they are not included in trace_entries.h
78  */
79 struct syscall_trace_enter {
80 	struct trace_entry	ent;
81 	int			nr;
82 	unsigned long		args[];
83 };
84 
85 struct syscall_trace_exit {
86 	struct trace_entry	ent;
87 	int			nr;
88 	long			ret;
89 };
90 
91 struct kprobe_trace_entry_head {
92 	struct trace_entry	ent;
93 	unsigned long		ip;
94 };
95 
96 struct kretprobe_trace_entry_head {
97 	struct trace_entry	ent;
98 	unsigned long		func;
99 	unsigned long		ret_ip;
100 };
101 
102 /*
103  * trace_flag_type is an enumeration that holds different
104  * states when a trace occurs. These are:
105  *  IRQS_OFF		- interrupts were disabled
106  *  IRQS_NOSUPPORT	- arch does not support irqs_disabled_flags
107  *  NEED_RESCHED	- reschedule is requested
108  *  HARDIRQ		- inside an interrupt handler
109  *  SOFTIRQ		- inside a softirq handler
110  */
111 enum trace_flag_type {
112 	TRACE_FLAG_IRQS_OFF		= 0x01,
113 	TRACE_FLAG_IRQS_NOSUPPORT	= 0x02,
114 	TRACE_FLAG_NEED_RESCHED		= 0x04,
115 	TRACE_FLAG_HARDIRQ		= 0x08,
116 	TRACE_FLAG_SOFTIRQ		= 0x10,
117 };
118 
119 #define TRACE_BUF_SIZE		1024
120 
121 /*
122  * The CPU trace array - it consists of thousands of trace entries
123  * plus some other descriptor data: (for example which task started
124  * the trace, etc.)
125  */
126 struct trace_array_cpu {
127 	atomic_t		disabled;
128 	void			*buffer_page;	/* ring buffer spare */
129 
130 	unsigned long		saved_latency;
131 	unsigned long		critical_start;
132 	unsigned long		critical_end;
133 	unsigned long		critical_sequence;
134 	unsigned long		nice;
135 	unsigned long		policy;
136 	unsigned long		rt_priority;
137 	unsigned long		skipped_entries;
138 	cycle_t			preempt_timestamp;
139 	pid_t			pid;
140 	uid_t			uid;
141 	char			comm[TASK_COMM_LEN];
142 };
143 
144 /*
145  * The trace array - an array of per-CPU trace arrays. This is the
146  * highest level data structure that individual tracers deal with.
147  * They have on/off state as well:
148  */
149 struct trace_array {
150 	struct ring_buffer	*buffer;
151 	unsigned long		entries;
152 	int			cpu;
153 	cycle_t			time_start;
154 	struct task_struct	*waiter;
155 	struct trace_array_cpu	*data[NR_CPUS];
156 };
157 
158 #define FTRACE_CMP_TYPE(var, type) \
159 	__builtin_types_compatible_p(typeof(var), type *)
160 
161 #undef IF_ASSIGN
162 #define IF_ASSIGN(var, entry, etype, id)		\
163 	if (FTRACE_CMP_TYPE(var, etype)) {		\
164 		var = (typeof(var))(entry);		\
165 		WARN_ON(id && (entry)->type != id);	\
166 		break;					\
167 	}
168 
169 /* Will cause compile errors if type is not found. */
170 extern void __ftrace_bad_type(void);
171 
172 /*
173  * The trace_assign_type is a verifier that the entry type is
174  * the same as the type being assigned. To add new types simply
175  * add a line with the following format:
176  *
177  * IF_ASSIGN(var, ent, type, id);
178  *
179  *  Where "type" is the trace type that includes the trace_entry
180  *  as the "ent" item. And "id" is the trace identifier that is
181  *  used in the trace_type enum.
182  *
183  *  If the type can have more than one id, then use zero.
184  */
185 #define trace_assign_type(var, ent)					\
186 	do {								\
187 		IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);	\
188 		IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);	\
189 		IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);	\
190 		IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
191 		IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);	\
192 		IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT);	\
193 		IF_ASSIGN(var, ent, struct special_entry, 0);		\
194 		IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,		\
195 			  TRACE_MMIO_RW);				\
196 		IF_ASSIGN(var, ent, struct trace_mmiotrace_map,		\
197 			  TRACE_MMIO_MAP);				\
198 		IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
199 		IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,	\
200 			  TRACE_GRAPH_ENT);		\
201 		IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,	\
202 			  TRACE_GRAPH_RET);		\
203 		IF_ASSIGN(var, ent, struct ksym_trace_entry, TRACE_KSYM);\
204 		__ftrace_bad_type();					\
205 	} while (0)
206 
207 /*
208  * An option specific to a tracer. This is a boolean value.
209  * The bit is the bit index that sets its value on the
210  * flags value in struct tracer_flags.
211  */
212 struct tracer_opt {
213 	const char	*name; /* Will appear on the trace_options file */
214 	u32		bit; /* Mask assigned in val field in tracer_flags */
215 };
216 
217 /*
218  * The set of specific options for a tracer. Your tracer
219  * have to set the initial value of the flags val.
220  */
221 struct tracer_flags {
222 	u32			val;
223 	struct tracer_opt	*opts;
224 };
225 
226 /* Makes more easy to define a tracer opt */
227 #define TRACER_OPT(s, b)	.name = #s, .bit = b
228 
229 
230 /**
231  * struct tracer - a specific tracer and its callbacks to interact with debugfs
232  * @name: the name chosen to select it on the available_tracers file
233  * @init: called when one switches to this tracer (echo name > current_tracer)
234  * @reset: called when one switches to another tracer
235  * @start: called when tracing is unpaused (echo 1 > tracing_enabled)
236  * @stop: called when tracing is paused (echo 0 > tracing_enabled)
237  * @open: called when the trace file is opened
238  * @pipe_open: called when the trace_pipe file is opened
239  * @wait_pipe: override how the user waits for traces on trace_pipe
240  * @close: called when the trace file is released
241  * @pipe_close: called when the trace_pipe file is released
242  * @read: override the default read callback on trace_pipe
243  * @splice_read: override the default splice_read callback on trace_pipe
244  * @selftest: selftest to run on boot (see trace_selftest.c)
245  * @print_headers: override the first lines that describe your columns
246  * @print_line: callback that prints a trace
247  * @set_flag: signals one of your private flags changed (trace_options file)
248  * @flags: your private flags
249  */
250 struct tracer {
251 	const char		*name;
252 	int			(*init)(struct trace_array *tr);
253 	void			(*reset)(struct trace_array *tr);
254 	void			(*start)(struct trace_array *tr);
255 	void			(*stop)(struct trace_array *tr);
256 	void			(*open)(struct trace_iterator *iter);
257 	void			(*pipe_open)(struct trace_iterator *iter);
258 	void			(*wait_pipe)(struct trace_iterator *iter);
259 	void			(*close)(struct trace_iterator *iter);
260 	void			(*pipe_close)(struct trace_iterator *iter);
261 	ssize_t			(*read)(struct trace_iterator *iter,
262 					struct file *filp, char __user *ubuf,
263 					size_t cnt, loff_t *ppos);
264 	ssize_t			(*splice_read)(struct trace_iterator *iter,
265 					       struct file *filp,
266 					       loff_t *ppos,
267 					       struct pipe_inode_info *pipe,
268 					       size_t len,
269 					       unsigned int flags);
270 #ifdef CONFIG_FTRACE_STARTUP_TEST
271 	int			(*selftest)(struct tracer *trace,
272 					    struct trace_array *tr);
273 #endif
274 	void			(*print_header)(struct seq_file *m);
275 	enum print_line_t	(*print_line)(struct trace_iterator *iter);
276 	/* If you handled the flag setting, return 0 */
277 	int			(*set_flag)(u32 old_flags, u32 bit, int set);
278 	struct tracer		*next;
279 	int			print_max;
280 	struct tracer_flags	*flags;
281 };
282 
283 
284 #define TRACE_PIPE_ALL_CPU	-1
285 
286 int tracer_init(struct tracer *t, struct trace_array *tr);
287 int tracing_is_enabled(void);
288 void trace_wake_up(void);
289 void tracing_reset(struct trace_array *tr, int cpu);
290 void tracing_reset_online_cpus(struct trace_array *tr);
291 void tracing_reset_current(int cpu);
292 void tracing_reset_current_online_cpus(void);
293 int tracing_open_generic(struct inode *inode, struct file *filp);
294 struct dentry *trace_create_file(const char *name,
295 				 mode_t mode,
296 				 struct dentry *parent,
297 				 void *data,
298 				 const struct file_operations *fops);
299 
300 struct dentry *tracing_init_dentry(void);
301 void init_tracer_sysprof_debugfs(struct dentry *d_tracer);
302 
303 struct ring_buffer_event;
304 
305 struct ring_buffer_event *
306 trace_buffer_lock_reserve(struct ring_buffer *buffer,
307 			  int type,
308 			  unsigned long len,
309 			  unsigned long flags,
310 			  int pc);
311 void trace_buffer_unlock_commit(struct ring_buffer *buffer,
312 				struct ring_buffer_event *event,
313 				unsigned long flags, int pc);
314 
315 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
316 						struct trace_array_cpu *data);
317 
318 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
319 					  int *ent_cpu, u64 *ent_ts);
320 
321 void default_wait_pipe(struct trace_iterator *iter);
322 void poll_wait_pipe(struct trace_iterator *iter);
323 
324 void ftrace(struct trace_array *tr,
325 			    struct trace_array_cpu *data,
326 			    unsigned long ip,
327 			    unsigned long parent_ip,
328 			    unsigned long flags, int pc);
329 void tracing_sched_switch_trace(struct trace_array *tr,
330 				struct task_struct *prev,
331 				struct task_struct *next,
332 				unsigned long flags, int pc);
333 
334 void tracing_sched_wakeup_trace(struct trace_array *tr,
335 				struct task_struct *wakee,
336 				struct task_struct *cur,
337 				unsigned long flags, int pc);
338 void trace_special(struct trace_array *tr,
339 		   struct trace_array_cpu *data,
340 		   unsigned long arg1,
341 		   unsigned long arg2,
342 		   unsigned long arg3, int pc);
343 void trace_function(struct trace_array *tr,
344 		    unsigned long ip,
345 		    unsigned long parent_ip,
346 		    unsigned long flags, int pc);
347 void trace_default_header(struct seq_file *m);
348 void print_trace_header(struct seq_file *m, struct trace_iterator *iter);
349 int trace_empty(struct trace_iterator *iter);
350 
351 void trace_graph_return(struct ftrace_graph_ret *trace);
352 int trace_graph_entry(struct ftrace_graph_ent *trace);
353 void set_graph_array(struct trace_array *tr);
354 
355 void tracing_start_cmdline_record(void);
356 void tracing_stop_cmdline_record(void);
357 void tracing_sched_switch_assign_trace(struct trace_array *tr);
358 void tracing_stop_sched_switch_record(void);
359 void tracing_start_sched_switch_record(void);
360 int register_tracer(struct tracer *type);
361 void unregister_tracer(struct tracer *type);
362 int is_tracing_stopped(void);
363 
364 extern int process_new_ksym_entry(char *ksymname, int op, unsigned long addr);
365 
366 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
367 
368 extern unsigned long tracing_thresh;
369 
370 #ifdef CONFIG_TRACER_MAX_TRACE
371 extern unsigned long tracing_max_latency;
372 
373 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
374 void update_max_tr_single(struct trace_array *tr,
375 			  struct task_struct *tsk, int cpu);
376 #endif /* CONFIG_TRACER_MAX_TRACE */
377 
378 #ifdef CONFIG_STACKTRACE
379 void ftrace_trace_stack(struct ring_buffer *buffer, unsigned long flags,
380 			int skip, int pc);
381 
382 void ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags,
383 			    int pc);
384 
385 void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
386 		   int pc);
387 #else
388 static inline void ftrace_trace_stack(struct ring_buffer *buffer,
389 				      unsigned long flags, int skip, int pc)
390 {
391 }
392 
393 static inline void ftrace_trace_userstack(struct ring_buffer *buffer,
394 					  unsigned long flags, int pc)
395 {
396 }
397 
398 static inline void __trace_stack(struct trace_array *tr, unsigned long flags,
399 				 int skip, int pc)
400 {
401 }
402 #endif /* CONFIG_STACKTRACE */
403 
404 extern cycle_t ftrace_now(int cpu);
405 
406 extern void trace_find_cmdline(int pid, char comm[]);
407 
408 #ifdef CONFIG_DYNAMIC_FTRACE
409 extern unsigned long ftrace_update_tot_cnt;
410 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
411 extern int DYN_FTRACE_TEST_NAME(void);
412 #endif
413 
414 extern int ring_buffer_expanded;
415 extern bool tracing_selftest_disabled;
416 DECLARE_PER_CPU(int, ftrace_cpu_disabled);
417 
418 #ifdef CONFIG_FTRACE_STARTUP_TEST
419 extern int trace_selftest_startup_function(struct tracer *trace,
420 					   struct trace_array *tr);
421 extern int trace_selftest_startup_function_graph(struct tracer *trace,
422 						 struct trace_array *tr);
423 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
424 					  struct trace_array *tr);
425 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
426 					     struct trace_array *tr);
427 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
428 						 struct trace_array *tr);
429 extern int trace_selftest_startup_wakeup(struct tracer *trace,
430 					 struct trace_array *tr);
431 extern int trace_selftest_startup_nop(struct tracer *trace,
432 					 struct trace_array *tr);
433 extern int trace_selftest_startup_sched_switch(struct tracer *trace,
434 					       struct trace_array *tr);
435 extern int trace_selftest_startup_sysprof(struct tracer *trace,
436 					       struct trace_array *tr);
437 extern int trace_selftest_startup_branch(struct tracer *trace,
438 					 struct trace_array *tr);
439 extern int trace_selftest_startup_ksym(struct tracer *trace,
440 					 struct trace_array *tr);
441 #endif /* CONFIG_FTRACE_STARTUP_TEST */
442 
443 extern void *head_page(struct trace_array_cpu *data);
444 extern unsigned long long ns2usecs(cycle_t nsec);
445 extern int
446 trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
447 extern int
448 trace_vprintk(unsigned long ip, const char *fmt, va_list args);
449 extern int
450 trace_array_vprintk(struct trace_array *tr,
451 		    unsigned long ip, const char *fmt, va_list args);
452 int trace_array_printk(struct trace_array *tr,
453 		       unsigned long ip, const char *fmt, ...);
454 
455 extern unsigned long trace_flags;
456 
457 extern int trace_clock_id;
458 
459 /* Standard output formatting function used for function return traces */
460 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
461 
462 /* Flag options */
463 #define TRACE_GRAPH_PRINT_OVERRUN       0x1
464 #define TRACE_GRAPH_PRINT_CPU           0x2
465 #define TRACE_GRAPH_PRINT_OVERHEAD      0x4
466 #define TRACE_GRAPH_PRINT_PROC          0x8
467 #define TRACE_GRAPH_PRINT_DURATION      0x10
468 #define TRACE_GRAPH_PRINT_ABS_TIME      0x20
469 
470 extern enum print_line_t
471 print_graph_function_flags(struct trace_iterator *iter, u32 flags);
472 extern void print_graph_headers_flags(struct seq_file *s, u32 flags);
473 extern enum print_line_t
474 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
475 extern void graph_trace_open(struct trace_iterator *iter);
476 extern void graph_trace_close(struct trace_iterator *iter);
477 extern int __trace_graph_entry(struct trace_array *tr,
478 			       struct ftrace_graph_ent *trace,
479 			       unsigned long flags, int pc);
480 extern void __trace_graph_return(struct trace_array *tr,
481 				 struct ftrace_graph_ret *trace,
482 				 unsigned long flags, int pc);
483 
484 
485 #ifdef CONFIG_DYNAMIC_FTRACE
486 /* TODO: make this variable */
487 #define FTRACE_GRAPH_MAX_FUNCS		32
488 extern int ftrace_graph_filter_enabled;
489 extern int ftrace_graph_count;
490 extern unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS];
491 
492 static inline int ftrace_graph_addr(unsigned long addr)
493 {
494 	int i;
495 
496 	if (!ftrace_graph_filter_enabled)
497 		return 1;
498 
499 	for (i = 0; i < ftrace_graph_count; i++) {
500 		if (addr == ftrace_graph_funcs[i])
501 			return 1;
502 	}
503 
504 	return 0;
505 }
506 #else
507 static inline int ftrace_graph_addr(unsigned long addr)
508 {
509 	return 1;
510 }
511 #endif /* CONFIG_DYNAMIC_FTRACE */
512 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
513 static inline enum print_line_t
514 print_graph_function_flags(struct trace_iterator *iter, u32 flags)
515 {
516 	return TRACE_TYPE_UNHANDLED;
517 }
518 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
519 
520 extern struct list_head ftrace_pids;
521 
522 #ifdef CONFIG_FUNCTION_TRACER
523 static inline int ftrace_trace_task(struct task_struct *task)
524 {
525 	if (list_empty(&ftrace_pids))
526 		return 1;
527 
528 	return test_tsk_trace_trace(task);
529 }
530 #else
531 static inline int ftrace_trace_task(struct task_struct *task)
532 {
533 	return 1;
534 }
535 #endif
536 
537 /*
538  * struct trace_parser - servers for reading the user input separated by spaces
539  * @cont: set if the input is not complete - no final space char was found
540  * @buffer: holds the parsed user input
541  * @idx: user input length
542  * @size: buffer size
543  */
544 struct trace_parser {
545 	bool		cont;
546 	char		*buffer;
547 	unsigned	idx;
548 	unsigned	size;
549 };
550 
551 static inline bool trace_parser_loaded(struct trace_parser *parser)
552 {
553 	return (parser->idx != 0);
554 }
555 
556 static inline bool trace_parser_cont(struct trace_parser *parser)
557 {
558 	return parser->cont;
559 }
560 
561 static inline void trace_parser_clear(struct trace_parser *parser)
562 {
563 	parser->cont = false;
564 	parser->idx = 0;
565 }
566 
567 extern int trace_parser_get_init(struct trace_parser *parser, int size);
568 extern void trace_parser_put(struct trace_parser *parser);
569 extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
570 	size_t cnt, loff_t *ppos);
571 
572 /*
573  * trace_iterator_flags is an enumeration that defines bit
574  * positions into trace_flags that controls the output.
575  *
576  * NOTE: These bits must match the trace_options array in
577  *       trace.c.
578  */
579 enum trace_iterator_flags {
580 	TRACE_ITER_PRINT_PARENT		= 0x01,
581 	TRACE_ITER_SYM_OFFSET		= 0x02,
582 	TRACE_ITER_SYM_ADDR		= 0x04,
583 	TRACE_ITER_VERBOSE		= 0x08,
584 	TRACE_ITER_RAW			= 0x10,
585 	TRACE_ITER_HEX			= 0x20,
586 	TRACE_ITER_BIN			= 0x40,
587 	TRACE_ITER_BLOCK		= 0x80,
588 	TRACE_ITER_STACKTRACE		= 0x100,
589 	TRACE_ITER_PRINTK		= 0x200,
590 	TRACE_ITER_PREEMPTONLY		= 0x400,
591 	TRACE_ITER_BRANCH		= 0x800,
592 	TRACE_ITER_ANNOTATE		= 0x1000,
593 	TRACE_ITER_USERSTACKTRACE       = 0x2000,
594 	TRACE_ITER_SYM_USEROBJ          = 0x4000,
595 	TRACE_ITER_PRINTK_MSGONLY	= 0x8000,
596 	TRACE_ITER_CONTEXT_INFO		= 0x10000, /* Print pid/cpu/time */
597 	TRACE_ITER_LATENCY_FMT		= 0x20000,
598 	TRACE_ITER_SLEEP_TIME		= 0x40000,
599 	TRACE_ITER_GRAPH_TIME		= 0x80000,
600 };
601 
602 /*
603  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
604  * control the output of kernel symbols.
605  */
606 #define TRACE_ITER_SYM_MASK \
607 	(TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
608 
609 extern struct tracer nop_trace;
610 
611 #ifdef CONFIG_BRANCH_TRACER
612 extern int enable_branch_tracing(struct trace_array *tr);
613 extern void disable_branch_tracing(void);
614 static inline int trace_branch_enable(struct trace_array *tr)
615 {
616 	if (trace_flags & TRACE_ITER_BRANCH)
617 		return enable_branch_tracing(tr);
618 	return 0;
619 }
620 static inline void trace_branch_disable(void)
621 {
622 	/* due to races, always disable */
623 	disable_branch_tracing();
624 }
625 #else
626 static inline int trace_branch_enable(struct trace_array *tr)
627 {
628 	return 0;
629 }
630 static inline void trace_branch_disable(void)
631 {
632 }
633 #endif /* CONFIG_BRANCH_TRACER */
634 
635 /* set ring buffers to default size if not already done so */
636 int tracing_update_buffers(void);
637 
638 /* trace event type bit fields, not numeric */
639 enum {
640 	TRACE_EVENT_TYPE_PRINTF		= 1,
641 	TRACE_EVENT_TYPE_RAW		= 2,
642 };
643 
644 struct ftrace_event_field {
645 	struct list_head	link;
646 	char			*name;
647 	char			*type;
648 	int			filter_type;
649 	int			offset;
650 	int			size;
651 	int			is_signed;
652 };
653 
654 struct event_filter {
655 	int			n_preds;
656 	struct filter_pred	**preds;
657 	char			*filter_string;
658 };
659 
660 struct event_subsystem {
661 	struct list_head	list;
662 	const char		*name;
663 	struct dentry		*entry;
664 	struct event_filter	*filter;
665 	int			nr_events;
666 };
667 
668 struct filter_pred;
669 struct regex;
670 
671 typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event,
672 				 int val1, int val2);
673 
674 typedef int (*regex_match_func)(char *str, struct regex *r, int len);
675 
676 enum regex_type {
677 	MATCH_FULL = 0,
678 	MATCH_FRONT_ONLY,
679 	MATCH_MIDDLE_ONLY,
680 	MATCH_END_ONLY,
681 };
682 
683 struct regex {
684 	char			pattern[MAX_FILTER_STR_VAL];
685 	int			len;
686 	int			field_len;
687 	regex_match_func	match;
688 };
689 
690 struct filter_pred {
691 	filter_pred_fn_t 	fn;
692 	u64 			val;
693 	struct regex		regex;
694 	char 			*field_name;
695 	int 			offset;
696 	int 			not;
697 	int 			op;
698 	int 			pop_n;
699 };
700 
701 extern struct list_head ftrace_common_fields;
702 
703 extern enum regex_type
704 filter_parse_regex(char *buff, int len, char **search, int *not);
705 extern void print_event_filter(struct ftrace_event_call *call,
706 			       struct trace_seq *s);
707 extern int apply_event_filter(struct ftrace_event_call *call,
708 			      char *filter_string);
709 extern int apply_subsystem_event_filter(struct event_subsystem *system,
710 					char *filter_string);
711 extern void print_subsystem_event_filter(struct event_subsystem *system,
712 					 struct trace_seq *s);
713 extern int filter_assign_type(const char *type);
714 
715 struct list_head *
716 trace_get_fields(struct ftrace_event_call *event_call);
717 
718 static inline int
719 filter_check_discard(struct ftrace_event_call *call, void *rec,
720 		     struct ring_buffer *buffer,
721 		     struct ring_buffer_event *event)
722 {
723 	if (unlikely(call->flags & TRACE_EVENT_FL_FILTERED) &&
724 	    !filter_match_preds(call->filter, rec)) {
725 		ring_buffer_discard_commit(buffer, event);
726 		return 1;
727 	}
728 
729 	return 0;
730 }
731 
732 extern struct mutex event_mutex;
733 extern struct list_head ftrace_events;
734 
735 extern const char *__start___trace_bprintk_fmt[];
736 extern const char *__stop___trace_bprintk_fmt[];
737 
738 #undef FTRACE_ENTRY
739 #define FTRACE_ENTRY(call, struct_name, id, tstruct, print)		\
740 	extern struct ftrace_event_call					\
741 	__attribute__((__aligned__(4))) event_##call;
742 #undef FTRACE_ENTRY_DUP
743 #define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print)		\
744 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
745 #include "trace_entries.h"
746 
747 #endif /* _LINUX_KERNEL_TRACE_H */
748