xref: /linux/kernel/trace/trace.h (revision 6863aaa88516292b885fdce5dd91925a00c3a3de)
1 // SPDX-License-Identifier: GPL-2.0
2 
3 #ifndef _LINUX_KERNEL_TRACE_H
4 #define _LINUX_KERNEL_TRACE_H
5 
6 #include <linux/fs.h>
7 #include <linux/atomic.h>
8 #include <linux/sched.h>
9 #include <linux/clocksource.h>
10 #include <linux/ring_buffer.h>
11 #include <linux/mmiotrace.h>
12 #include <linux/tracepoint.h>
13 #include <linux/ftrace.h>
14 #include <linux/trace.h>
15 #include <linux/hw_breakpoint.h>
16 #include <linux/trace_seq.h>
17 #include <linux/trace_events.h>
18 #include <linux/compiler.h>
19 #include <linux/glob.h>
20 #include <linux/irq_work.h>
21 #include <linux/workqueue.h>
22 #include <linux/ctype.h>
23 #include <linux/once_lite.h>
24 
25 #include "pid_list.h"
26 
27 #ifdef CONFIG_FTRACE_SYSCALLS
28 #include <asm/unistd.h>		/* For NR_SYSCALLS	     */
29 #include <asm/syscall.h>	/* some archs define it here */
30 #endif
31 
32 #define TRACE_MODE_WRITE	0640
33 #define TRACE_MODE_READ		0440
34 
35 enum trace_type {
36 	__TRACE_FIRST_TYPE = 0,
37 
38 	TRACE_FN,
39 	TRACE_CTX,
40 	TRACE_WAKE,
41 	TRACE_STACK,
42 	TRACE_PRINT,
43 	TRACE_BPRINT,
44 	TRACE_MMIO_RW,
45 	TRACE_MMIO_MAP,
46 	TRACE_BRANCH,
47 	TRACE_GRAPH_RET,
48 	TRACE_GRAPH_ENT,
49 	TRACE_USER_STACK,
50 	TRACE_BLK,
51 	TRACE_BPUTS,
52 	TRACE_HWLAT,
53 	TRACE_OSNOISE,
54 	TRACE_TIMERLAT,
55 	TRACE_RAW_DATA,
56 	TRACE_FUNC_REPEATS,
57 
58 	__TRACE_LAST_TYPE,
59 };
60 
61 
62 #undef __field
63 #define __field(type, item)		type	item;
64 
65 #undef __field_fn
66 #define __field_fn(type, item)		type	item;
67 
68 #undef __field_struct
69 #define __field_struct(type, item)	__field(type, item)
70 
71 #undef __field_desc
72 #define __field_desc(type, container, item)
73 
74 #undef __field_packed
75 #define __field_packed(type, container, item)
76 
77 #undef __array
78 #define __array(type, item, size)	type	item[size];
79 
80 #undef __array_desc
81 #define __array_desc(type, container, item, size)
82 
83 #undef __dynamic_array
84 #define __dynamic_array(type, item)	type	item[];
85 
86 #undef __rel_dynamic_array
87 #define __rel_dynamic_array(type, item)	type	item[];
88 
89 #undef F_STRUCT
90 #define F_STRUCT(args...)		args
91 
92 #undef FTRACE_ENTRY
93 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print)		\
94 	struct struct_name {						\
95 		struct trace_entry	ent;				\
96 		tstruct							\
97 	}
98 
99 #undef FTRACE_ENTRY_DUP
100 #define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk)
101 
102 #undef FTRACE_ENTRY_REG
103 #define FTRACE_ENTRY_REG(name, struct_name, id, tstruct, print,	regfn)	\
104 	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print))
105 
106 #undef FTRACE_ENTRY_PACKED
107 #define FTRACE_ENTRY_PACKED(name, struct_name, id, tstruct, print)	\
108 	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print)) __packed
109 
110 #include "trace_entries.h"
111 
112 /* Use this for memory failure errors */
113 #define MEM_FAIL(condition, fmt, ...)					\
114 	DO_ONCE_LITE_IF(condition, pr_err, "ERROR: " fmt, ##__VA_ARGS__)
115 
116 /*
117  * syscalls are special, and need special handling, this is why
118  * they are not included in trace_entries.h
119  */
120 struct syscall_trace_enter {
121 	struct trace_entry	ent;
122 	int			nr;
123 	unsigned long		args[];
124 };
125 
126 struct syscall_trace_exit {
127 	struct trace_entry	ent;
128 	int			nr;
129 	long			ret;
130 };
131 
132 struct kprobe_trace_entry_head {
133 	struct trace_entry	ent;
134 	unsigned long		ip;
135 };
136 
137 struct eprobe_trace_entry_head {
138 	struct trace_entry	ent;
139 };
140 
141 struct kretprobe_trace_entry_head {
142 	struct trace_entry	ent;
143 	unsigned long		func;
144 	unsigned long		ret_ip;
145 };
146 
147 #define TRACE_BUF_SIZE		1024
148 
149 struct trace_array;
150 
151 /*
152  * The CPU trace array - it consists of thousands of trace entries
153  * plus some other descriptor data: (for example which task started
154  * the trace, etc.)
155  */
156 struct trace_array_cpu {
157 	atomic_t		disabled;
158 	void			*buffer_page;	/* ring buffer spare */
159 
160 	unsigned long		entries;
161 	unsigned long		saved_latency;
162 	unsigned long		critical_start;
163 	unsigned long		critical_end;
164 	unsigned long		critical_sequence;
165 	unsigned long		nice;
166 	unsigned long		policy;
167 	unsigned long		rt_priority;
168 	unsigned long		skipped_entries;
169 	u64			preempt_timestamp;
170 	pid_t			pid;
171 	kuid_t			uid;
172 	char			comm[TASK_COMM_LEN];
173 
174 #ifdef CONFIG_FUNCTION_TRACER
175 	int			ftrace_ignore_pid;
176 #endif
177 	bool			ignore_pid;
178 };
179 
180 struct tracer;
181 struct trace_option_dentry;
182 
183 struct array_buffer {
184 	struct trace_array		*tr;
185 	struct trace_buffer		*buffer;
186 	struct trace_array_cpu __percpu	*data;
187 	u64				time_start;
188 	int				cpu;
189 };
190 
191 #define TRACE_FLAGS_MAX_SIZE		32
192 
193 struct trace_options {
194 	struct tracer			*tracer;
195 	struct trace_option_dentry	*topts;
196 };
197 
198 struct trace_pid_list *trace_pid_list_alloc(void);
199 void trace_pid_list_free(struct trace_pid_list *pid_list);
200 bool trace_pid_list_is_set(struct trace_pid_list *pid_list, unsigned int pid);
201 int trace_pid_list_set(struct trace_pid_list *pid_list, unsigned int pid);
202 int trace_pid_list_clear(struct trace_pid_list *pid_list, unsigned int pid);
203 int trace_pid_list_first(struct trace_pid_list *pid_list, unsigned int *pid);
204 int trace_pid_list_next(struct trace_pid_list *pid_list, unsigned int pid,
205 			unsigned int *next);
206 
207 enum {
208 	TRACE_PIDS		= BIT(0),
209 	TRACE_NO_PIDS		= BIT(1),
210 };
211 
212 static inline bool pid_type_enabled(int type, struct trace_pid_list *pid_list,
213 				    struct trace_pid_list *no_pid_list)
214 {
215 	/* Return true if the pid list in type has pids */
216 	return ((type & TRACE_PIDS) && pid_list) ||
217 		((type & TRACE_NO_PIDS) && no_pid_list);
218 }
219 
220 static inline bool still_need_pid_events(int type, struct trace_pid_list *pid_list,
221 					 struct trace_pid_list *no_pid_list)
222 {
223 	/*
224 	 * Turning off what is in @type, return true if the "other"
225 	 * pid list, still has pids in it.
226 	 */
227 	return (!(type & TRACE_PIDS) && pid_list) ||
228 		(!(type & TRACE_NO_PIDS) && no_pid_list);
229 }
230 
231 typedef bool (*cond_update_fn_t)(struct trace_array *tr, void *cond_data);
232 
233 /**
234  * struct cond_snapshot - conditional snapshot data and callback
235  *
236  * The cond_snapshot structure encapsulates a callback function and
237  * data associated with the snapshot for a given tracing instance.
238  *
239  * When a snapshot is taken conditionally, by invoking
240  * tracing_snapshot_cond(tr, cond_data), the cond_data passed in is
241  * passed in turn to the cond_snapshot.update() function.  That data
242  * can be compared by the update() implementation with the cond_data
243  * contained within the struct cond_snapshot instance associated with
244  * the trace_array.  Because the tr->max_lock is held throughout the
245  * update() call, the update() function can directly retrieve the
246  * cond_snapshot and cond_data associated with the per-instance
247  * snapshot associated with the trace_array.
248  *
249  * The cond_snapshot.update() implementation can save data to be
250  * associated with the snapshot if it decides to, and returns 'true'
251  * in that case, or it returns 'false' if the conditional snapshot
252  * shouldn't be taken.
253  *
254  * The cond_snapshot instance is created and associated with the
255  * user-defined cond_data by tracing_cond_snapshot_enable().
256  * Likewise, the cond_snapshot instance is destroyed and is no longer
257  * associated with the trace instance by
258  * tracing_cond_snapshot_disable().
259  *
260  * The method below is required.
261  *
262  * @update: When a conditional snapshot is invoked, the update()
263  *	callback function is invoked with the tr->max_lock held.  The
264  *	update() implementation signals whether or not to actually
265  *	take the snapshot, by returning 'true' if so, 'false' if no
266  *	snapshot should be taken.  Because the max_lock is held for
267  *	the duration of update(), the implementation is safe to
268  *	directly retrieved and save any implementation data it needs
269  *	to in association with the snapshot.
270  */
271 struct cond_snapshot {
272 	void				*cond_data;
273 	cond_update_fn_t		update;
274 };
275 
276 /*
277  * struct trace_func_repeats - used to keep track of the consecutive
278  * (on the same CPU) calls of a single function.
279  */
280 struct trace_func_repeats {
281 	unsigned long	ip;
282 	unsigned long	parent_ip;
283 	unsigned long	count;
284 	u64		ts_last_call;
285 };
286 
287 /*
288  * The trace array - an array of per-CPU trace arrays. This is the
289  * highest level data structure that individual tracers deal with.
290  * They have on/off state as well:
291  */
292 struct trace_array {
293 	struct list_head	list;
294 	char			*name;
295 	struct array_buffer	array_buffer;
296 #ifdef CONFIG_TRACER_MAX_TRACE
297 	/*
298 	 * The max_buffer is used to snapshot the trace when a maximum
299 	 * latency is reached, or when the user initiates a snapshot.
300 	 * Some tracers will use this to store a maximum trace while
301 	 * it continues examining live traces.
302 	 *
303 	 * The buffers for the max_buffer are set up the same as the array_buffer
304 	 * When a snapshot is taken, the buffer of the max_buffer is swapped
305 	 * with the buffer of the array_buffer and the buffers are reset for
306 	 * the array_buffer so the tracing can continue.
307 	 */
308 	struct array_buffer	max_buffer;
309 	bool			allocated_snapshot;
310 #endif
311 #if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER) \
312 	|| defined(CONFIG_OSNOISE_TRACER)
313 	unsigned long		max_latency;
314 #ifdef CONFIG_FSNOTIFY
315 	struct dentry		*d_max_latency;
316 	struct work_struct	fsnotify_work;
317 	struct irq_work		fsnotify_irqwork;
318 #endif
319 #endif
320 	struct trace_pid_list	__rcu *filtered_pids;
321 	struct trace_pid_list	__rcu *filtered_no_pids;
322 	/*
323 	 * max_lock is used to protect the swapping of buffers
324 	 * when taking a max snapshot. The buffers themselves are
325 	 * protected by per_cpu spinlocks. But the action of the swap
326 	 * needs its own lock.
327 	 *
328 	 * This is defined as a arch_spinlock_t in order to help
329 	 * with performance when lockdep debugging is enabled.
330 	 *
331 	 * It is also used in other places outside the update_max_tr
332 	 * so it needs to be defined outside of the
333 	 * CONFIG_TRACER_MAX_TRACE.
334 	 */
335 	arch_spinlock_t		max_lock;
336 	int			buffer_disabled;
337 #ifdef CONFIG_FTRACE_SYSCALLS
338 	int			sys_refcount_enter;
339 	int			sys_refcount_exit;
340 	struct trace_event_file __rcu *enter_syscall_files[NR_syscalls];
341 	struct trace_event_file __rcu *exit_syscall_files[NR_syscalls];
342 #endif
343 	int			stop_count;
344 	int			clock_id;
345 	int			nr_topts;
346 	bool			clear_trace;
347 	int			buffer_percent;
348 	unsigned int		n_err_log_entries;
349 	struct tracer		*current_trace;
350 	unsigned int		trace_flags;
351 	unsigned char		trace_flags_index[TRACE_FLAGS_MAX_SIZE];
352 	unsigned int		flags;
353 	raw_spinlock_t		start_lock;
354 	struct list_head	err_log;
355 	struct dentry		*dir;
356 	struct dentry		*options;
357 	struct dentry		*percpu_dir;
358 	struct dentry		*event_dir;
359 	struct trace_options	*topts;
360 	struct list_head	systems;
361 	struct list_head	events;
362 	struct trace_event_file *trace_marker_file;
363 	cpumask_var_t		tracing_cpumask; /* only trace on set CPUs */
364 	int			ref;
365 	int			trace_ref;
366 #ifdef CONFIG_FUNCTION_TRACER
367 	struct ftrace_ops	*ops;
368 	struct trace_pid_list	__rcu *function_pids;
369 	struct trace_pid_list	__rcu *function_no_pids;
370 #ifdef CONFIG_DYNAMIC_FTRACE
371 	/* All of these are protected by the ftrace_lock */
372 	struct list_head	func_probes;
373 	struct list_head	mod_trace;
374 	struct list_head	mod_notrace;
375 #endif
376 	/* function tracing enabled */
377 	int			function_enabled;
378 #endif
379 	int			no_filter_buffering_ref;
380 	struct list_head	hist_vars;
381 #ifdef CONFIG_TRACER_SNAPSHOT
382 	struct cond_snapshot	*cond_snapshot;
383 #endif
384 	struct trace_func_repeats	__percpu *last_func_repeats;
385 };
386 
387 enum {
388 	TRACE_ARRAY_FL_GLOBAL	= (1 << 0)
389 };
390 
391 extern struct list_head ftrace_trace_arrays;
392 
393 extern struct mutex trace_types_lock;
394 
395 extern int trace_array_get(struct trace_array *tr);
396 extern int tracing_check_open_get_tr(struct trace_array *tr);
397 extern struct trace_array *trace_array_find(const char *instance);
398 extern struct trace_array *trace_array_find_get(const char *instance);
399 
400 extern u64 tracing_event_time_stamp(struct trace_buffer *buffer, struct ring_buffer_event *rbe);
401 extern int tracing_set_filter_buffering(struct trace_array *tr, bool set);
402 extern int tracing_set_clock(struct trace_array *tr, const char *clockstr);
403 
404 extern bool trace_clock_in_ns(struct trace_array *tr);
405 
406 /*
407  * The global tracer (top) should be the first trace array added,
408  * but we check the flag anyway.
409  */
410 static inline struct trace_array *top_trace_array(void)
411 {
412 	struct trace_array *tr;
413 
414 	if (list_empty(&ftrace_trace_arrays))
415 		return NULL;
416 
417 	tr = list_entry(ftrace_trace_arrays.prev,
418 			typeof(*tr), list);
419 	WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
420 	return tr;
421 }
422 
423 #define FTRACE_CMP_TYPE(var, type) \
424 	__builtin_types_compatible_p(typeof(var), type *)
425 
426 #undef IF_ASSIGN
427 #define IF_ASSIGN(var, entry, etype, id)			\
428 	if (FTRACE_CMP_TYPE(var, etype)) {			\
429 		var = (typeof(var))(entry);			\
430 		WARN_ON(id != 0 && (entry)->type != id);	\
431 		break;						\
432 	}
433 
434 /* Will cause compile errors if type is not found. */
435 extern void __ftrace_bad_type(void);
436 
437 /*
438  * The trace_assign_type is a verifier that the entry type is
439  * the same as the type being assigned. To add new types simply
440  * add a line with the following format:
441  *
442  * IF_ASSIGN(var, ent, type, id);
443  *
444  *  Where "type" is the trace type that includes the trace_entry
445  *  as the "ent" item. And "id" is the trace identifier that is
446  *  used in the trace_type enum.
447  *
448  *  If the type can have more than one id, then use zero.
449  */
450 #define trace_assign_type(var, ent)					\
451 	do {								\
452 		IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);	\
453 		IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);	\
454 		IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);	\
455 		IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
456 		IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);	\
457 		IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT);	\
458 		IF_ASSIGN(var, ent, struct bputs_entry, TRACE_BPUTS);	\
459 		IF_ASSIGN(var, ent, struct hwlat_entry, TRACE_HWLAT);	\
460 		IF_ASSIGN(var, ent, struct osnoise_entry, TRACE_OSNOISE);\
461 		IF_ASSIGN(var, ent, struct timerlat_entry, TRACE_TIMERLAT);\
462 		IF_ASSIGN(var, ent, struct raw_data_entry, TRACE_RAW_DATA);\
463 		IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,		\
464 			  TRACE_MMIO_RW);				\
465 		IF_ASSIGN(var, ent, struct trace_mmiotrace_map,		\
466 			  TRACE_MMIO_MAP);				\
467 		IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
468 		IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,	\
469 			  TRACE_GRAPH_ENT);		\
470 		IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,	\
471 			  TRACE_GRAPH_RET);		\
472 		IF_ASSIGN(var, ent, struct func_repeats_entry,		\
473 			  TRACE_FUNC_REPEATS);				\
474 		__ftrace_bad_type();					\
475 	} while (0)
476 
477 /*
478  * An option specific to a tracer. This is a boolean value.
479  * The bit is the bit index that sets its value on the
480  * flags value in struct tracer_flags.
481  */
482 struct tracer_opt {
483 	const char	*name; /* Will appear on the trace_options file */
484 	u32		bit; /* Mask assigned in val field in tracer_flags */
485 };
486 
487 /*
488  * The set of specific options for a tracer. Your tracer
489  * have to set the initial value of the flags val.
490  */
491 struct tracer_flags {
492 	u32			val;
493 	struct tracer_opt	*opts;
494 	struct tracer		*trace;
495 };
496 
497 /* Makes more easy to define a tracer opt */
498 #define TRACER_OPT(s, b)	.name = #s, .bit = b
499 
500 
501 struct trace_option_dentry {
502 	struct tracer_opt		*opt;
503 	struct tracer_flags		*flags;
504 	struct trace_array		*tr;
505 	struct dentry			*entry;
506 };
507 
508 /**
509  * struct tracer - a specific tracer and its callbacks to interact with tracefs
510  * @name: the name chosen to select it on the available_tracers file
511  * @init: called when one switches to this tracer (echo name > current_tracer)
512  * @reset: called when one switches to another tracer
513  * @start: called when tracing is unpaused (echo 1 > tracing_on)
514  * @stop: called when tracing is paused (echo 0 > tracing_on)
515  * @update_thresh: called when tracing_thresh is updated
516  * @open: called when the trace file is opened
517  * @pipe_open: called when the trace_pipe file is opened
518  * @close: called when the trace file is released
519  * @pipe_close: called when the trace_pipe file is released
520  * @read: override the default read callback on trace_pipe
521  * @splice_read: override the default splice_read callback on trace_pipe
522  * @selftest: selftest to run on boot (see trace_selftest.c)
523  * @print_headers: override the first lines that describe your columns
524  * @print_line: callback that prints a trace
525  * @set_flag: signals one of your private flags changed (trace_options file)
526  * @flags: your private flags
527  */
528 struct tracer {
529 	const char		*name;
530 	int			(*init)(struct trace_array *tr);
531 	void			(*reset)(struct trace_array *tr);
532 	void			(*start)(struct trace_array *tr);
533 	void			(*stop)(struct trace_array *tr);
534 	int			(*update_thresh)(struct trace_array *tr);
535 	void			(*open)(struct trace_iterator *iter);
536 	void			(*pipe_open)(struct trace_iterator *iter);
537 	void			(*close)(struct trace_iterator *iter);
538 	void			(*pipe_close)(struct trace_iterator *iter);
539 	ssize_t			(*read)(struct trace_iterator *iter,
540 					struct file *filp, char __user *ubuf,
541 					size_t cnt, loff_t *ppos);
542 	ssize_t			(*splice_read)(struct trace_iterator *iter,
543 					       struct file *filp,
544 					       loff_t *ppos,
545 					       struct pipe_inode_info *pipe,
546 					       size_t len,
547 					       unsigned int flags);
548 #ifdef CONFIG_FTRACE_STARTUP_TEST
549 	int			(*selftest)(struct tracer *trace,
550 					    struct trace_array *tr);
551 #endif
552 	void			(*print_header)(struct seq_file *m);
553 	enum print_line_t	(*print_line)(struct trace_iterator *iter);
554 	/* If you handled the flag setting, return 0 */
555 	int			(*set_flag)(struct trace_array *tr,
556 					    u32 old_flags, u32 bit, int set);
557 	/* Return 0 if OK with change, else return non-zero */
558 	int			(*flag_changed)(struct trace_array *tr,
559 						u32 mask, int set);
560 	struct tracer		*next;
561 	struct tracer_flags	*flags;
562 	int			enabled;
563 	bool			print_max;
564 	bool			allow_instances;
565 #ifdef CONFIG_TRACER_MAX_TRACE
566 	bool			use_max_tr;
567 #endif
568 	/* True if tracer cannot be enabled in kernel param */
569 	bool			noboot;
570 };
571 
572 static inline struct ring_buffer_iter *
573 trace_buffer_iter(struct trace_iterator *iter, int cpu)
574 {
575 	return iter->buffer_iter ? iter->buffer_iter[cpu] : NULL;
576 }
577 
578 int tracer_init(struct tracer *t, struct trace_array *tr);
579 int tracing_is_enabled(void);
580 void tracing_reset_online_cpus(struct array_buffer *buf);
581 void tracing_reset_current(int cpu);
582 void tracing_reset_all_online_cpus(void);
583 int tracing_open_generic(struct inode *inode, struct file *filp);
584 int tracing_open_generic_tr(struct inode *inode, struct file *filp);
585 bool tracing_is_disabled(void);
586 bool tracer_tracing_is_on(struct trace_array *tr);
587 void tracer_tracing_on(struct trace_array *tr);
588 void tracer_tracing_off(struct trace_array *tr);
589 struct dentry *trace_create_file(const char *name,
590 				 umode_t mode,
591 				 struct dentry *parent,
592 				 void *data,
593 				 const struct file_operations *fops);
594 
595 int tracing_init_dentry(void);
596 
597 struct ring_buffer_event;
598 
599 struct ring_buffer_event *
600 trace_buffer_lock_reserve(struct trace_buffer *buffer,
601 			  int type,
602 			  unsigned long len,
603 			  unsigned int trace_ctx);
604 
605 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
606 						struct trace_array_cpu *data);
607 
608 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
609 					  int *ent_cpu, u64 *ent_ts);
610 
611 void trace_buffer_unlock_commit_nostack(struct trace_buffer *buffer,
612 					struct ring_buffer_event *event);
613 
614 bool trace_is_tracepoint_string(const char *str);
615 const char *trace_event_format(struct trace_iterator *iter, const char *fmt);
616 void trace_check_vprintf(struct trace_iterator *iter, const char *fmt,
617 			 va_list ap);
618 
619 int trace_empty(struct trace_iterator *iter);
620 
621 void *trace_find_next_entry_inc(struct trace_iterator *iter);
622 
623 void trace_init_global_iter(struct trace_iterator *iter);
624 
625 void tracing_iter_reset(struct trace_iterator *iter, int cpu);
626 
627 unsigned long trace_total_entries_cpu(struct trace_array *tr, int cpu);
628 unsigned long trace_total_entries(struct trace_array *tr);
629 
630 void trace_function(struct trace_array *tr,
631 		    unsigned long ip,
632 		    unsigned long parent_ip,
633 		    unsigned int trace_ctx);
634 void trace_graph_function(struct trace_array *tr,
635 		    unsigned long ip,
636 		    unsigned long parent_ip,
637 		    unsigned int trace_ctx);
638 void trace_latency_header(struct seq_file *m);
639 void trace_default_header(struct seq_file *m);
640 void print_trace_header(struct seq_file *m, struct trace_iterator *iter);
641 
642 void trace_graph_return(struct ftrace_graph_ret *trace);
643 int trace_graph_entry(struct ftrace_graph_ent *trace);
644 void set_graph_array(struct trace_array *tr);
645 
646 void tracing_start_cmdline_record(void);
647 void tracing_stop_cmdline_record(void);
648 void tracing_start_tgid_record(void);
649 void tracing_stop_tgid_record(void);
650 
651 int register_tracer(struct tracer *type);
652 int is_tracing_stopped(void);
653 
654 loff_t tracing_lseek(struct file *file, loff_t offset, int whence);
655 
656 extern cpumask_var_t __read_mostly tracing_buffer_mask;
657 
658 #define for_each_tracing_cpu(cpu)	\
659 	for_each_cpu(cpu, tracing_buffer_mask)
660 
661 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
662 
663 extern unsigned long tracing_thresh;
664 
665 /* PID filtering */
666 
667 extern int pid_max;
668 
669 bool trace_find_filtered_pid(struct trace_pid_list *filtered_pids,
670 			     pid_t search_pid);
671 bool trace_ignore_this_task(struct trace_pid_list *filtered_pids,
672 			    struct trace_pid_list *filtered_no_pids,
673 			    struct task_struct *task);
674 void trace_filter_add_remove_task(struct trace_pid_list *pid_list,
675 				  struct task_struct *self,
676 				  struct task_struct *task);
677 void *trace_pid_next(struct trace_pid_list *pid_list, void *v, loff_t *pos);
678 void *trace_pid_start(struct trace_pid_list *pid_list, loff_t *pos);
679 int trace_pid_show(struct seq_file *m, void *v);
680 void trace_free_pid_list(struct trace_pid_list *pid_list);
681 int trace_pid_write(struct trace_pid_list *filtered_pids,
682 		    struct trace_pid_list **new_pid_list,
683 		    const char __user *ubuf, size_t cnt);
684 
685 #ifdef CONFIG_TRACER_MAX_TRACE
686 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu,
687 		   void *cond_data);
688 void update_max_tr_single(struct trace_array *tr,
689 			  struct task_struct *tsk, int cpu);
690 #endif /* CONFIG_TRACER_MAX_TRACE */
691 
692 #if (defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER) \
693 	|| defined(CONFIG_OSNOISE_TRACER)) && defined(CONFIG_FSNOTIFY)
694 #define LATENCY_FS_NOTIFY
695 #endif
696 
697 #ifdef LATENCY_FS_NOTIFY
698 void latency_fsnotify(struct trace_array *tr);
699 #else
700 static inline void latency_fsnotify(struct trace_array *tr) { }
701 #endif
702 
703 #ifdef CONFIG_STACKTRACE
704 void __trace_stack(struct trace_array *tr, unsigned int trace_ctx, int skip);
705 #else
706 static inline void __trace_stack(struct trace_array *tr, unsigned int trace_ctx,
707 				 int skip)
708 {
709 }
710 #endif /* CONFIG_STACKTRACE */
711 
712 void trace_last_func_repeats(struct trace_array *tr,
713 			     struct trace_func_repeats *last_info,
714 			     unsigned int trace_ctx);
715 
716 extern u64 ftrace_now(int cpu);
717 
718 extern void trace_find_cmdline(int pid, char comm[]);
719 extern int trace_find_tgid(int pid);
720 extern void trace_event_follow_fork(struct trace_array *tr, bool enable);
721 
722 #ifdef CONFIG_DYNAMIC_FTRACE
723 extern unsigned long ftrace_update_tot_cnt;
724 extern unsigned long ftrace_number_of_pages;
725 extern unsigned long ftrace_number_of_groups;
726 void ftrace_init_trace_array(struct trace_array *tr);
727 #else
728 static inline void ftrace_init_trace_array(struct trace_array *tr) { }
729 #endif
730 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
731 extern int DYN_FTRACE_TEST_NAME(void);
732 #define DYN_FTRACE_TEST_NAME2 trace_selftest_dynamic_test_func2
733 extern int DYN_FTRACE_TEST_NAME2(void);
734 
735 extern bool ring_buffer_expanded;
736 extern bool tracing_selftest_disabled;
737 
738 #ifdef CONFIG_FTRACE_STARTUP_TEST
739 extern void __init disable_tracing_selftest(const char *reason);
740 
741 extern int trace_selftest_startup_function(struct tracer *trace,
742 					   struct trace_array *tr);
743 extern int trace_selftest_startup_function_graph(struct tracer *trace,
744 						 struct trace_array *tr);
745 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
746 					  struct trace_array *tr);
747 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
748 					     struct trace_array *tr);
749 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
750 						 struct trace_array *tr);
751 extern int trace_selftest_startup_wakeup(struct tracer *trace,
752 					 struct trace_array *tr);
753 extern int trace_selftest_startup_nop(struct tracer *trace,
754 					 struct trace_array *tr);
755 extern int trace_selftest_startup_branch(struct tracer *trace,
756 					 struct trace_array *tr);
757 /*
758  * Tracer data references selftest functions that only occur
759  * on boot up. These can be __init functions. Thus, when selftests
760  * are enabled, then the tracers need to reference __init functions.
761  */
762 #define __tracer_data		__refdata
763 #else
764 static inline void __init disable_tracing_selftest(const char *reason)
765 {
766 }
767 /* Tracers are seldom changed. Optimize when selftests are disabled. */
768 #define __tracer_data		__read_mostly
769 #endif /* CONFIG_FTRACE_STARTUP_TEST */
770 
771 extern void *head_page(struct trace_array_cpu *data);
772 extern unsigned long long ns2usecs(u64 nsec);
773 extern int
774 trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
775 extern int
776 trace_vprintk(unsigned long ip, const char *fmt, va_list args);
777 extern int
778 trace_array_vprintk(struct trace_array *tr,
779 		    unsigned long ip, const char *fmt, va_list args);
780 int trace_array_printk_buf(struct trace_buffer *buffer,
781 			   unsigned long ip, const char *fmt, ...);
782 void trace_printk_seq(struct trace_seq *s);
783 enum print_line_t print_trace_line(struct trace_iterator *iter);
784 
785 extern char trace_find_mark(unsigned long long duration);
786 
787 struct ftrace_hash;
788 
789 struct ftrace_mod_load {
790 	struct list_head	list;
791 	char			*func;
792 	char			*module;
793 	int			 enable;
794 };
795 
796 enum {
797 	FTRACE_HASH_FL_MOD	= (1 << 0),
798 };
799 
800 struct ftrace_hash {
801 	unsigned long		size_bits;
802 	struct hlist_head	*buckets;
803 	unsigned long		count;
804 	unsigned long		flags;
805 	struct rcu_head		rcu;
806 };
807 
808 struct ftrace_func_entry *
809 ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip);
810 
811 static __always_inline bool ftrace_hash_empty(struct ftrace_hash *hash)
812 {
813 	return !hash || !(hash->count || (hash->flags & FTRACE_HASH_FL_MOD));
814 }
815 
816 /* Standard output formatting function used for function return traces */
817 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
818 
819 /* Flag options */
820 #define TRACE_GRAPH_PRINT_OVERRUN       0x1
821 #define TRACE_GRAPH_PRINT_CPU           0x2
822 #define TRACE_GRAPH_PRINT_OVERHEAD      0x4
823 #define TRACE_GRAPH_PRINT_PROC          0x8
824 #define TRACE_GRAPH_PRINT_DURATION      0x10
825 #define TRACE_GRAPH_PRINT_ABS_TIME      0x20
826 #define TRACE_GRAPH_PRINT_REL_TIME      0x40
827 #define TRACE_GRAPH_PRINT_IRQS          0x80
828 #define TRACE_GRAPH_PRINT_TAIL          0x100
829 #define TRACE_GRAPH_SLEEP_TIME          0x200
830 #define TRACE_GRAPH_GRAPH_TIME          0x400
831 #define TRACE_GRAPH_PRINT_FILL_SHIFT	28
832 #define TRACE_GRAPH_PRINT_FILL_MASK	(0x3 << TRACE_GRAPH_PRINT_FILL_SHIFT)
833 
834 extern void ftrace_graph_sleep_time_control(bool enable);
835 
836 #ifdef CONFIG_FUNCTION_PROFILER
837 extern void ftrace_graph_graph_time_control(bool enable);
838 #else
839 static inline void ftrace_graph_graph_time_control(bool enable) { }
840 #endif
841 
842 extern enum print_line_t
843 print_graph_function_flags(struct trace_iterator *iter, u32 flags);
844 extern void print_graph_headers_flags(struct seq_file *s, u32 flags);
845 extern void
846 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
847 extern void graph_trace_open(struct trace_iterator *iter);
848 extern void graph_trace_close(struct trace_iterator *iter);
849 extern int __trace_graph_entry(struct trace_array *tr,
850 			       struct ftrace_graph_ent *trace,
851 			       unsigned int trace_ctx);
852 extern void __trace_graph_return(struct trace_array *tr,
853 				 struct ftrace_graph_ret *trace,
854 				 unsigned int trace_ctx);
855 
856 #ifdef CONFIG_DYNAMIC_FTRACE
857 extern struct ftrace_hash __rcu *ftrace_graph_hash;
858 extern struct ftrace_hash __rcu *ftrace_graph_notrace_hash;
859 
860 static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace)
861 {
862 	unsigned long addr = trace->func;
863 	int ret = 0;
864 	struct ftrace_hash *hash;
865 
866 	preempt_disable_notrace();
867 
868 	/*
869 	 * Have to open code "rcu_dereference_sched()" because the
870 	 * function graph tracer can be called when RCU is not
871 	 * "watching".
872 	 * Protected with schedule_on_each_cpu(ftrace_sync)
873 	 */
874 	hash = rcu_dereference_protected(ftrace_graph_hash, !preemptible());
875 
876 	if (ftrace_hash_empty(hash)) {
877 		ret = 1;
878 		goto out;
879 	}
880 
881 	if (ftrace_lookup_ip(hash, addr)) {
882 
883 		/*
884 		 * This needs to be cleared on the return functions
885 		 * when the depth is zero.
886 		 */
887 		trace_recursion_set(TRACE_GRAPH_BIT);
888 		trace_recursion_set_depth(trace->depth);
889 
890 		/*
891 		 * If no irqs are to be traced, but a set_graph_function
892 		 * is set, and called by an interrupt handler, we still
893 		 * want to trace it.
894 		 */
895 		if (in_hardirq())
896 			trace_recursion_set(TRACE_IRQ_BIT);
897 		else
898 			trace_recursion_clear(TRACE_IRQ_BIT);
899 		ret = 1;
900 	}
901 
902 out:
903 	preempt_enable_notrace();
904 	return ret;
905 }
906 
907 static inline void ftrace_graph_addr_finish(struct ftrace_graph_ret *trace)
908 {
909 	if (trace_recursion_test(TRACE_GRAPH_BIT) &&
910 	    trace->depth == trace_recursion_depth())
911 		trace_recursion_clear(TRACE_GRAPH_BIT);
912 }
913 
914 static inline int ftrace_graph_notrace_addr(unsigned long addr)
915 {
916 	int ret = 0;
917 	struct ftrace_hash *notrace_hash;
918 
919 	preempt_disable_notrace();
920 
921 	/*
922 	 * Have to open code "rcu_dereference_sched()" because the
923 	 * function graph tracer can be called when RCU is not
924 	 * "watching".
925 	 * Protected with schedule_on_each_cpu(ftrace_sync)
926 	 */
927 	notrace_hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
928 						 !preemptible());
929 
930 	if (ftrace_lookup_ip(notrace_hash, addr))
931 		ret = 1;
932 
933 	preempt_enable_notrace();
934 	return ret;
935 }
936 #else
937 static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace)
938 {
939 	return 1;
940 }
941 
942 static inline int ftrace_graph_notrace_addr(unsigned long addr)
943 {
944 	return 0;
945 }
946 static inline void ftrace_graph_addr_finish(struct ftrace_graph_ret *trace)
947 { }
948 #endif /* CONFIG_DYNAMIC_FTRACE */
949 
950 extern unsigned int fgraph_max_depth;
951 
952 static inline bool ftrace_graph_ignore_func(struct ftrace_graph_ent *trace)
953 {
954 	/* trace it when it is-nested-in or is a function enabled. */
955 	return !(trace_recursion_test(TRACE_GRAPH_BIT) ||
956 		 ftrace_graph_addr(trace)) ||
957 		(trace->depth < 0) ||
958 		(fgraph_max_depth && trace->depth >= fgraph_max_depth);
959 }
960 
961 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
962 static inline enum print_line_t
963 print_graph_function_flags(struct trace_iterator *iter, u32 flags)
964 {
965 	return TRACE_TYPE_UNHANDLED;
966 }
967 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
968 
969 extern struct list_head ftrace_pids;
970 
971 #ifdef CONFIG_FUNCTION_TRACER
972 
973 #define FTRACE_PID_IGNORE	-1
974 #define FTRACE_PID_TRACE	-2
975 
976 struct ftrace_func_command {
977 	struct list_head	list;
978 	char			*name;
979 	int			(*func)(struct trace_array *tr,
980 					struct ftrace_hash *hash,
981 					char *func, char *cmd,
982 					char *params, int enable);
983 };
984 extern bool ftrace_filter_param __initdata;
985 static inline int ftrace_trace_task(struct trace_array *tr)
986 {
987 	return this_cpu_read(tr->array_buffer.data->ftrace_ignore_pid) !=
988 		FTRACE_PID_IGNORE;
989 }
990 extern int ftrace_is_dead(void);
991 int ftrace_create_function_files(struct trace_array *tr,
992 				 struct dentry *parent);
993 void ftrace_destroy_function_files(struct trace_array *tr);
994 int ftrace_allocate_ftrace_ops(struct trace_array *tr);
995 void ftrace_free_ftrace_ops(struct trace_array *tr);
996 void ftrace_init_global_array_ops(struct trace_array *tr);
997 void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func);
998 void ftrace_reset_array_ops(struct trace_array *tr);
999 void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer);
1000 void ftrace_init_tracefs_toplevel(struct trace_array *tr,
1001 				  struct dentry *d_tracer);
1002 void ftrace_clear_pids(struct trace_array *tr);
1003 int init_function_trace(void);
1004 void ftrace_pid_follow_fork(struct trace_array *tr, bool enable);
1005 #else
1006 static inline int ftrace_trace_task(struct trace_array *tr)
1007 {
1008 	return 1;
1009 }
1010 static inline int ftrace_is_dead(void) { return 0; }
1011 static inline int
1012 ftrace_create_function_files(struct trace_array *tr,
1013 			     struct dentry *parent)
1014 {
1015 	return 0;
1016 }
1017 static inline int ftrace_allocate_ftrace_ops(struct trace_array *tr)
1018 {
1019 	return 0;
1020 }
1021 static inline void ftrace_free_ftrace_ops(struct trace_array *tr) { }
1022 static inline void ftrace_destroy_function_files(struct trace_array *tr) { }
1023 static inline __init void
1024 ftrace_init_global_array_ops(struct trace_array *tr) { }
1025 static inline void ftrace_reset_array_ops(struct trace_array *tr) { }
1026 static inline void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d) { }
1027 static inline void ftrace_init_tracefs_toplevel(struct trace_array *tr, struct dentry *d) { }
1028 static inline void ftrace_clear_pids(struct trace_array *tr) { }
1029 static inline int init_function_trace(void) { return 0; }
1030 static inline void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) { }
1031 /* ftace_func_t type is not defined, use macro instead of static inline */
1032 #define ftrace_init_array_ops(tr, func) do { } while (0)
1033 #endif /* CONFIG_FUNCTION_TRACER */
1034 
1035 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
1036 
1037 struct ftrace_probe_ops {
1038 	void			(*func)(unsigned long ip,
1039 					unsigned long parent_ip,
1040 					struct trace_array *tr,
1041 					struct ftrace_probe_ops *ops,
1042 					void *data);
1043 	int			(*init)(struct ftrace_probe_ops *ops,
1044 					struct trace_array *tr,
1045 					unsigned long ip, void *init_data,
1046 					void **data);
1047 	void			(*free)(struct ftrace_probe_ops *ops,
1048 					struct trace_array *tr,
1049 					unsigned long ip, void *data);
1050 	int			(*print)(struct seq_file *m,
1051 					 unsigned long ip,
1052 					 struct ftrace_probe_ops *ops,
1053 					 void *data);
1054 };
1055 
1056 struct ftrace_func_mapper;
1057 typedef int (*ftrace_mapper_func)(void *data);
1058 
1059 struct ftrace_func_mapper *allocate_ftrace_func_mapper(void);
1060 void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
1061 					   unsigned long ip);
1062 int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
1063 			       unsigned long ip, void *data);
1064 void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
1065 				   unsigned long ip);
1066 void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
1067 			     ftrace_mapper_func free_func);
1068 
1069 extern int
1070 register_ftrace_function_probe(char *glob, struct trace_array *tr,
1071 			       struct ftrace_probe_ops *ops, void *data);
1072 extern int
1073 unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
1074 				      struct ftrace_probe_ops *ops);
1075 extern void clear_ftrace_function_probes(struct trace_array *tr);
1076 
1077 int register_ftrace_command(struct ftrace_func_command *cmd);
1078 int unregister_ftrace_command(struct ftrace_func_command *cmd);
1079 
1080 void ftrace_create_filter_files(struct ftrace_ops *ops,
1081 				struct dentry *parent);
1082 void ftrace_destroy_filter_files(struct ftrace_ops *ops);
1083 
1084 extern int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
1085 			     int len, int reset);
1086 extern int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
1087 			      int len, int reset);
1088 #else
1089 struct ftrace_func_command;
1090 
1091 static inline __init int register_ftrace_command(struct ftrace_func_command *cmd)
1092 {
1093 	return -EINVAL;
1094 }
1095 static inline __init int unregister_ftrace_command(char *cmd_name)
1096 {
1097 	return -EINVAL;
1098 }
1099 static inline void clear_ftrace_function_probes(struct trace_array *tr)
1100 {
1101 }
1102 
1103 /*
1104  * The ops parameter passed in is usually undefined.
1105  * This must be a macro.
1106  */
1107 #define ftrace_create_filter_files(ops, parent) do { } while (0)
1108 #define ftrace_destroy_filter_files(ops) do { } while (0)
1109 #endif /* CONFIG_FUNCTION_TRACER && CONFIG_DYNAMIC_FTRACE */
1110 
1111 bool ftrace_event_is_function(struct trace_event_call *call);
1112 
1113 /*
1114  * struct trace_parser - servers for reading the user input separated by spaces
1115  * @cont: set if the input is not complete - no final space char was found
1116  * @buffer: holds the parsed user input
1117  * @idx: user input length
1118  * @size: buffer size
1119  */
1120 struct trace_parser {
1121 	bool		cont;
1122 	char		*buffer;
1123 	unsigned	idx;
1124 	unsigned	size;
1125 };
1126 
1127 static inline bool trace_parser_loaded(struct trace_parser *parser)
1128 {
1129 	return (parser->idx != 0);
1130 }
1131 
1132 static inline bool trace_parser_cont(struct trace_parser *parser)
1133 {
1134 	return parser->cont;
1135 }
1136 
1137 static inline void trace_parser_clear(struct trace_parser *parser)
1138 {
1139 	parser->cont = false;
1140 	parser->idx = 0;
1141 }
1142 
1143 extern int trace_parser_get_init(struct trace_parser *parser, int size);
1144 extern void trace_parser_put(struct trace_parser *parser);
1145 extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
1146 	size_t cnt, loff_t *ppos);
1147 
1148 /*
1149  * Only create function graph options if function graph is configured.
1150  */
1151 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1152 # define FGRAPH_FLAGS						\
1153 		C(DISPLAY_GRAPH,	"display-graph"),
1154 #else
1155 # define FGRAPH_FLAGS
1156 #endif
1157 
1158 #ifdef CONFIG_BRANCH_TRACER
1159 # define BRANCH_FLAGS					\
1160 		C(BRANCH,		"branch"),
1161 #else
1162 # define BRANCH_FLAGS
1163 #endif
1164 
1165 #ifdef CONFIG_FUNCTION_TRACER
1166 # define FUNCTION_FLAGS						\
1167 		C(FUNCTION,		"function-trace"),	\
1168 		C(FUNC_FORK,		"function-fork"),
1169 # define FUNCTION_DEFAULT_FLAGS		TRACE_ITER_FUNCTION
1170 #else
1171 # define FUNCTION_FLAGS
1172 # define FUNCTION_DEFAULT_FLAGS		0UL
1173 # define TRACE_ITER_FUNC_FORK		0UL
1174 #endif
1175 
1176 #ifdef CONFIG_STACKTRACE
1177 # define STACK_FLAGS				\
1178 		C(STACKTRACE,		"stacktrace"),
1179 #else
1180 # define STACK_FLAGS
1181 #endif
1182 
1183 /*
1184  * trace_iterator_flags is an enumeration that defines bit
1185  * positions into trace_flags that controls the output.
1186  *
1187  * NOTE: These bits must match the trace_options array in
1188  *       trace.c (this macro guarantees it).
1189  */
1190 #define TRACE_FLAGS						\
1191 		C(PRINT_PARENT,		"print-parent"),	\
1192 		C(SYM_OFFSET,		"sym-offset"),		\
1193 		C(SYM_ADDR,		"sym-addr"),		\
1194 		C(VERBOSE,		"verbose"),		\
1195 		C(RAW,			"raw"),			\
1196 		C(HEX,			"hex"),			\
1197 		C(BIN,			"bin"),			\
1198 		C(BLOCK,		"block"),		\
1199 		C(PRINTK,		"trace_printk"),	\
1200 		C(ANNOTATE,		"annotate"),		\
1201 		C(USERSTACKTRACE,	"userstacktrace"),	\
1202 		C(SYM_USEROBJ,		"sym-userobj"),		\
1203 		C(PRINTK_MSGONLY,	"printk-msg-only"),	\
1204 		C(CONTEXT_INFO,		"context-info"),   /* Print pid/cpu/time */ \
1205 		C(LATENCY_FMT,		"latency-format"),	\
1206 		C(RECORD_CMD,		"record-cmd"),		\
1207 		C(RECORD_TGID,		"record-tgid"),		\
1208 		C(OVERWRITE,		"overwrite"),		\
1209 		C(STOP_ON_FREE,		"disable_on_free"),	\
1210 		C(IRQ_INFO,		"irq-info"),		\
1211 		C(MARKERS,		"markers"),		\
1212 		C(EVENT_FORK,		"event-fork"),		\
1213 		C(PAUSE_ON_TRACE,	"pause-on-trace"),	\
1214 		C(HASH_PTR,		"hash-ptr"),	/* Print hashed pointer */ \
1215 		FUNCTION_FLAGS					\
1216 		FGRAPH_FLAGS					\
1217 		STACK_FLAGS					\
1218 		BRANCH_FLAGS
1219 
1220 /*
1221  * By defining C, we can make TRACE_FLAGS a list of bit names
1222  * that will define the bits for the flag masks.
1223  */
1224 #undef C
1225 #define C(a, b) TRACE_ITER_##a##_BIT
1226 
1227 enum trace_iterator_bits {
1228 	TRACE_FLAGS
1229 	/* Make sure we don't go more than we have bits for */
1230 	TRACE_ITER_LAST_BIT
1231 };
1232 
1233 /*
1234  * By redefining C, we can make TRACE_FLAGS a list of masks that
1235  * use the bits as defined above.
1236  */
1237 #undef C
1238 #define C(a, b) TRACE_ITER_##a = (1 << TRACE_ITER_##a##_BIT)
1239 
1240 enum trace_iterator_flags { TRACE_FLAGS };
1241 
1242 /*
1243  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
1244  * control the output of kernel symbols.
1245  */
1246 #define TRACE_ITER_SYM_MASK \
1247 	(TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
1248 
1249 extern struct tracer nop_trace;
1250 
1251 #ifdef CONFIG_BRANCH_TRACER
1252 extern int enable_branch_tracing(struct trace_array *tr);
1253 extern void disable_branch_tracing(void);
1254 static inline int trace_branch_enable(struct trace_array *tr)
1255 {
1256 	if (tr->trace_flags & TRACE_ITER_BRANCH)
1257 		return enable_branch_tracing(tr);
1258 	return 0;
1259 }
1260 static inline void trace_branch_disable(void)
1261 {
1262 	/* due to races, always disable */
1263 	disable_branch_tracing();
1264 }
1265 #else
1266 static inline int trace_branch_enable(struct trace_array *tr)
1267 {
1268 	return 0;
1269 }
1270 static inline void trace_branch_disable(void)
1271 {
1272 }
1273 #endif /* CONFIG_BRANCH_TRACER */
1274 
1275 /* set ring buffers to default size if not already done so */
1276 int tracing_update_buffers(void);
1277 
1278 struct ftrace_event_field {
1279 	struct list_head	link;
1280 	const char		*name;
1281 	const char		*type;
1282 	int			filter_type;
1283 	int			offset;
1284 	int			size;
1285 	int			is_signed;
1286 };
1287 
1288 struct prog_entry;
1289 
1290 struct event_filter {
1291 	struct prog_entry __rcu	*prog;
1292 	char			*filter_string;
1293 };
1294 
1295 struct event_subsystem {
1296 	struct list_head	list;
1297 	const char		*name;
1298 	struct event_filter	*filter;
1299 	int			ref_count;
1300 };
1301 
1302 struct trace_subsystem_dir {
1303 	struct list_head		list;
1304 	struct event_subsystem		*subsystem;
1305 	struct trace_array		*tr;
1306 	struct dentry			*entry;
1307 	int				ref_count;
1308 	int				nr_events;
1309 };
1310 
1311 extern int call_filter_check_discard(struct trace_event_call *call, void *rec,
1312 				     struct trace_buffer *buffer,
1313 				     struct ring_buffer_event *event);
1314 
1315 void trace_buffer_unlock_commit_regs(struct trace_array *tr,
1316 				     struct trace_buffer *buffer,
1317 				     struct ring_buffer_event *event,
1318 				     unsigned int trcace_ctx,
1319 				     struct pt_regs *regs);
1320 
1321 static inline void trace_buffer_unlock_commit(struct trace_array *tr,
1322 					      struct trace_buffer *buffer,
1323 					      struct ring_buffer_event *event,
1324 					      unsigned int trace_ctx)
1325 {
1326 	trace_buffer_unlock_commit_regs(tr, buffer, event, trace_ctx, NULL);
1327 }
1328 
1329 DECLARE_PER_CPU(struct ring_buffer_event *, trace_buffered_event);
1330 DECLARE_PER_CPU(int, trace_buffered_event_cnt);
1331 void trace_buffered_event_disable(void);
1332 void trace_buffered_event_enable(void);
1333 
1334 static inline void
1335 __trace_event_discard_commit(struct trace_buffer *buffer,
1336 			     struct ring_buffer_event *event)
1337 {
1338 	if (this_cpu_read(trace_buffered_event) == event) {
1339 		/* Simply release the temp buffer and enable preemption */
1340 		this_cpu_dec(trace_buffered_event_cnt);
1341 		preempt_enable_notrace();
1342 		return;
1343 	}
1344 	/* ring_buffer_discard_commit() enables preemption */
1345 	ring_buffer_discard_commit(buffer, event);
1346 }
1347 
1348 /*
1349  * Helper function for event_trigger_unlock_commit{_regs}().
1350  * If there are event triggers attached to this event that requires
1351  * filtering against its fields, then they will be called as the
1352  * entry already holds the field information of the current event.
1353  *
1354  * It also checks if the event should be discarded or not.
1355  * It is to be discarded if the event is soft disabled and the
1356  * event was only recorded to process triggers, or if the event
1357  * filter is active and this event did not match the filters.
1358  *
1359  * Returns true if the event is discarded, false otherwise.
1360  */
1361 static inline bool
1362 __event_trigger_test_discard(struct trace_event_file *file,
1363 			     struct trace_buffer *buffer,
1364 			     struct ring_buffer_event *event,
1365 			     void *entry,
1366 			     enum event_trigger_type *tt)
1367 {
1368 	unsigned long eflags = file->flags;
1369 
1370 	if (eflags & EVENT_FILE_FL_TRIGGER_COND)
1371 		*tt = event_triggers_call(file, buffer, entry, event);
1372 
1373 	if (likely(!(file->flags & (EVENT_FILE_FL_SOFT_DISABLED |
1374 				    EVENT_FILE_FL_FILTERED |
1375 				    EVENT_FILE_FL_PID_FILTER))))
1376 		return false;
1377 
1378 	if (file->flags & EVENT_FILE_FL_SOFT_DISABLED)
1379 		goto discard;
1380 
1381 	if (file->flags & EVENT_FILE_FL_FILTERED &&
1382 	    !filter_match_preds(file->filter, entry))
1383 		goto discard;
1384 
1385 	if ((file->flags & EVENT_FILE_FL_PID_FILTER) &&
1386 	    trace_event_ignore_this_pid(file))
1387 		goto discard;
1388 
1389 	return false;
1390  discard:
1391 	__trace_event_discard_commit(buffer, event);
1392 	return true;
1393 }
1394 
1395 /**
1396  * event_trigger_unlock_commit - handle triggers and finish event commit
1397  * @file: The file pointer associated with the event
1398  * @buffer: The ring buffer that the event is being written to
1399  * @event: The event meta data in the ring buffer
1400  * @entry: The event itself
1401  * @trace_ctx: The tracing context flags.
1402  *
1403  * This is a helper function to handle triggers that require data
1404  * from the event itself. It also tests the event against filters and
1405  * if the event is soft disabled and should be discarded.
1406  */
1407 static inline void
1408 event_trigger_unlock_commit(struct trace_event_file *file,
1409 			    struct trace_buffer *buffer,
1410 			    struct ring_buffer_event *event,
1411 			    void *entry, unsigned int trace_ctx)
1412 {
1413 	enum event_trigger_type tt = ETT_NONE;
1414 
1415 	if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1416 		trace_buffer_unlock_commit(file->tr, buffer, event, trace_ctx);
1417 
1418 	if (tt)
1419 		event_triggers_post_call(file, tt);
1420 }
1421 
1422 #define FILTER_PRED_INVALID	((unsigned short)-1)
1423 #define FILTER_PRED_IS_RIGHT	(1 << 15)
1424 #define FILTER_PRED_FOLD	(1 << 15)
1425 
1426 /*
1427  * The max preds is the size of unsigned short with
1428  * two flags at the MSBs. One bit is used for both the IS_RIGHT
1429  * and FOLD flags. The other is reserved.
1430  *
1431  * 2^14 preds is way more than enough.
1432  */
1433 #define MAX_FILTER_PRED		16384
1434 
1435 struct filter_pred;
1436 struct regex;
1437 
1438 typedef int (*regex_match_func)(char *str, struct regex *r, int len);
1439 
1440 enum regex_type {
1441 	MATCH_FULL = 0,
1442 	MATCH_FRONT_ONLY,
1443 	MATCH_MIDDLE_ONLY,
1444 	MATCH_END_ONLY,
1445 	MATCH_GLOB,
1446 	MATCH_INDEX,
1447 };
1448 
1449 struct regex {
1450 	char			pattern[MAX_FILTER_STR_VAL];
1451 	int			len;
1452 	int			field_len;
1453 	regex_match_func	match;
1454 };
1455 
1456 static inline bool is_string_field(struct ftrace_event_field *field)
1457 {
1458 	return field->filter_type == FILTER_DYN_STRING ||
1459 	       field->filter_type == FILTER_RDYN_STRING ||
1460 	       field->filter_type == FILTER_STATIC_STRING ||
1461 	       field->filter_type == FILTER_PTR_STRING ||
1462 	       field->filter_type == FILTER_COMM;
1463 }
1464 
1465 static inline bool is_function_field(struct ftrace_event_field *field)
1466 {
1467 	return field->filter_type == FILTER_TRACE_FN;
1468 }
1469 
1470 extern enum regex_type
1471 filter_parse_regex(char *buff, int len, char **search, int *not);
1472 extern void print_event_filter(struct trace_event_file *file,
1473 			       struct trace_seq *s);
1474 extern int apply_event_filter(struct trace_event_file *file,
1475 			      char *filter_string);
1476 extern int apply_subsystem_event_filter(struct trace_subsystem_dir *dir,
1477 					char *filter_string);
1478 extern void print_subsystem_event_filter(struct event_subsystem *system,
1479 					 struct trace_seq *s);
1480 extern int filter_assign_type(const char *type);
1481 extern int create_event_filter(struct trace_array *tr,
1482 			       struct trace_event_call *call,
1483 			       char *filter_str, bool set_str,
1484 			       struct event_filter **filterp);
1485 extern void free_event_filter(struct event_filter *filter);
1486 
1487 struct ftrace_event_field *
1488 trace_find_event_field(struct trace_event_call *call, char *name);
1489 
1490 extern void trace_event_enable_cmd_record(bool enable);
1491 extern void trace_event_enable_tgid_record(bool enable);
1492 
1493 extern int event_trace_init(void);
1494 extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
1495 extern int event_trace_del_tracer(struct trace_array *tr);
1496 extern void __trace_early_add_events(struct trace_array *tr);
1497 
1498 extern struct trace_event_file *__find_event_file(struct trace_array *tr,
1499 						  const char *system,
1500 						  const char *event);
1501 extern struct trace_event_file *find_event_file(struct trace_array *tr,
1502 						const char *system,
1503 						const char *event);
1504 
1505 static inline void *event_file_data(struct file *filp)
1506 {
1507 	return READ_ONCE(file_inode(filp)->i_private);
1508 }
1509 
1510 extern struct mutex event_mutex;
1511 extern struct list_head ftrace_events;
1512 
1513 extern const struct file_operations event_trigger_fops;
1514 extern const struct file_operations event_hist_fops;
1515 extern const struct file_operations event_hist_debug_fops;
1516 extern const struct file_operations event_inject_fops;
1517 
1518 #ifdef CONFIG_HIST_TRIGGERS
1519 extern int register_trigger_hist_cmd(void);
1520 extern int register_trigger_hist_enable_disable_cmds(void);
1521 #else
1522 static inline int register_trigger_hist_cmd(void) { return 0; }
1523 static inline int register_trigger_hist_enable_disable_cmds(void) { return 0; }
1524 #endif
1525 
1526 extern int register_trigger_cmds(void);
1527 extern void clear_event_triggers(struct trace_array *tr);
1528 
1529 enum {
1530 	EVENT_TRIGGER_FL_PROBE		= BIT(0),
1531 };
1532 
1533 struct event_trigger_data {
1534 	unsigned long			count;
1535 	int				ref;
1536 	int				flags;
1537 	struct event_trigger_ops	*ops;
1538 	struct event_command		*cmd_ops;
1539 	struct event_filter __rcu	*filter;
1540 	char				*filter_str;
1541 	void				*private_data;
1542 	bool				paused;
1543 	bool				paused_tmp;
1544 	struct list_head		list;
1545 	char				*name;
1546 	struct list_head		named_list;
1547 	struct event_trigger_data	*named_data;
1548 };
1549 
1550 /* Avoid typos */
1551 #define ENABLE_EVENT_STR	"enable_event"
1552 #define DISABLE_EVENT_STR	"disable_event"
1553 #define ENABLE_HIST_STR		"enable_hist"
1554 #define DISABLE_HIST_STR	"disable_hist"
1555 
1556 struct enable_trigger_data {
1557 	struct trace_event_file		*file;
1558 	bool				enable;
1559 	bool				hist;
1560 };
1561 
1562 extern int event_enable_trigger_print(struct seq_file *m,
1563 				      struct event_trigger_data *data);
1564 extern void event_enable_trigger_free(struct event_trigger_data *data);
1565 extern int event_enable_trigger_parse(struct event_command *cmd_ops,
1566 				      struct trace_event_file *file,
1567 				      char *glob, char *cmd,
1568 				      char *param_and_filter);
1569 extern int event_enable_register_trigger(char *glob,
1570 					 struct event_trigger_data *data,
1571 					 struct trace_event_file *file);
1572 extern void event_enable_unregister_trigger(char *glob,
1573 					    struct event_trigger_data *test,
1574 					    struct trace_event_file *file);
1575 extern void trigger_data_free(struct event_trigger_data *data);
1576 extern int event_trigger_init(struct event_trigger_data *data);
1577 extern int trace_event_trigger_enable_disable(struct trace_event_file *file,
1578 					      int trigger_enable);
1579 extern void update_cond_flag(struct trace_event_file *file);
1580 extern int set_trigger_filter(char *filter_str,
1581 			      struct event_trigger_data *trigger_data,
1582 			      struct trace_event_file *file);
1583 extern struct event_trigger_data *find_named_trigger(const char *name);
1584 extern bool is_named_trigger(struct event_trigger_data *test);
1585 extern int save_named_trigger(const char *name,
1586 			      struct event_trigger_data *data);
1587 extern void del_named_trigger(struct event_trigger_data *data);
1588 extern void pause_named_trigger(struct event_trigger_data *data);
1589 extern void unpause_named_trigger(struct event_trigger_data *data);
1590 extern void set_named_trigger_data(struct event_trigger_data *data,
1591 				   struct event_trigger_data *named_data);
1592 extern struct event_trigger_data *
1593 get_named_trigger_data(struct event_trigger_data *data);
1594 extern int register_event_command(struct event_command *cmd);
1595 extern int unregister_event_command(struct event_command *cmd);
1596 extern int register_trigger_hist_enable_disable_cmds(void);
1597 extern bool event_trigger_check_remove(const char *glob);
1598 extern bool event_trigger_empty_param(const char *param);
1599 extern int event_trigger_separate_filter(char *param_and_filter, char **param,
1600 					 char **filter, bool param_required);
1601 extern struct event_trigger_data *
1602 event_trigger_alloc(struct event_command *cmd_ops,
1603 		    char *cmd,
1604 		    char *param,
1605 		    void *private_data);
1606 extern int event_trigger_parse_num(char *trigger,
1607 				   struct event_trigger_data *trigger_data);
1608 extern int event_trigger_set_filter(struct event_command *cmd_ops,
1609 				    struct trace_event_file *file,
1610 				    char *param,
1611 				    struct event_trigger_data *trigger_data);
1612 extern void event_trigger_reset_filter(struct event_command *cmd_ops,
1613 				       struct event_trigger_data *trigger_data);
1614 extern int event_trigger_register(struct event_command *cmd_ops,
1615 				  struct trace_event_file *file,
1616 				  char *glob,
1617 				  struct event_trigger_data *trigger_data);
1618 extern void event_trigger_unregister(struct event_command *cmd_ops,
1619 				     struct trace_event_file *file,
1620 				     char *glob,
1621 				     struct event_trigger_data *trigger_data);
1622 
1623 /**
1624  * struct event_trigger_ops - callbacks for trace event triggers
1625  *
1626  * The methods in this structure provide per-event trigger hooks for
1627  * various trigger operations.
1628  *
1629  * The @init and @free methods are used during trigger setup and
1630  * teardown, typically called from an event_command's @parse()
1631  * function implementation.
1632  *
1633  * The @print method is used to print the trigger spec.
1634  *
1635  * The @trigger method is the function that actually implements the
1636  * trigger and is called in the context of the triggering event
1637  * whenever that event occurs.
1638  *
1639  * All the methods below, except for @init() and @free(), must be
1640  * implemented.
1641  *
1642  * @trigger: The trigger 'probe' function called when the triggering
1643  *	event occurs.  The data passed into this callback is the data
1644  *	that was supplied to the event_command @reg() function that
1645  *	registered the trigger (see struct event_command) along with
1646  *	the trace record, rec.
1647  *
1648  * @init: An optional initialization function called for the trigger
1649  *	when the trigger is registered (via the event_command reg()
1650  *	function).  This can be used to perform per-trigger
1651  *	initialization such as incrementing a per-trigger reference
1652  *	count, for instance.  This is usually implemented by the
1653  *	generic utility function @event_trigger_init() (see
1654  *	trace_event_triggers.c).
1655  *
1656  * @free: An optional de-initialization function called for the
1657  *	trigger when the trigger is unregistered (via the
1658  *	event_command @reg() function).  This can be used to perform
1659  *	per-trigger de-initialization such as decrementing a
1660  *	per-trigger reference count and freeing corresponding trigger
1661  *	data, for instance.  This is usually implemented by the
1662  *	generic utility function @event_trigger_free() (see
1663  *	trace_event_triggers.c).
1664  *
1665  * @print: The callback function invoked to have the trigger print
1666  *	itself.  This is usually implemented by a wrapper function
1667  *	that calls the generic utility function @event_trigger_print()
1668  *	(see trace_event_triggers.c).
1669  */
1670 struct event_trigger_ops {
1671 	void			(*trigger)(struct event_trigger_data *data,
1672 					   struct trace_buffer *buffer,
1673 					   void *rec,
1674 					   struct ring_buffer_event *rbe);
1675 	int			(*init)(struct event_trigger_data *data);
1676 	void			(*free)(struct event_trigger_data *data);
1677 	int			(*print)(struct seq_file *m,
1678 					 struct event_trigger_data *data);
1679 };
1680 
1681 /**
1682  * struct event_command - callbacks and data members for event commands
1683  *
1684  * Event commands are invoked by users by writing the command name
1685  * into the 'trigger' file associated with a trace event.  The
1686  * parameters associated with a specific invocation of an event
1687  * command are used to create an event trigger instance, which is
1688  * added to the list of trigger instances associated with that trace
1689  * event.  When the event is hit, the set of triggers associated with
1690  * that event is invoked.
1691  *
1692  * The data members in this structure provide per-event command data
1693  * for various event commands.
1694  *
1695  * All the data members below, except for @post_trigger, must be set
1696  * for each event command.
1697  *
1698  * @name: The unique name that identifies the event command.  This is
1699  *	the name used when setting triggers via trigger files.
1700  *
1701  * @trigger_type: A unique id that identifies the event command
1702  *	'type'.  This value has two purposes, the first to ensure that
1703  *	only one trigger of the same type can be set at a given time
1704  *	for a particular event e.g. it doesn't make sense to have both
1705  *	a traceon and traceoff trigger attached to a single event at
1706  *	the same time, so traceon and traceoff have the same type
1707  *	though they have different names.  The @trigger_type value is
1708  *	also used as a bit value for deferring the actual trigger
1709  *	action until after the current event is finished.  Some
1710  *	commands need to do this if they themselves log to the trace
1711  *	buffer (see the @post_trigger() member below).  @trigger_type
1712  *	values are defined by adding new values to the trigger_type
1713  *	enum in include/linux/trace_events.h.
1714  *
1715  * @flags: See the enum event_command_flags below.
1716  *
1717  * All the methods below, except for @set_filter() and @unreg_all(),
1718  * must be implemented.
1719  *
1720  * @parse: The callback function responsible for parsing and
1721  *	registering the trigger written to the 'trigger' file by the
1722  *	user.  It allocates the trigger instance and registers it with
1723  *	the appropriate trace event.  It makes use of the other
1724  *	event_command callback functions to orchestrate this, and is
1725  *	usually implemented by the generic utility function
1726  *	@event_trigger_callback() (see trace_event_triggers.c).
1727  *
1728  * @reg: Adds the trigger to the list of triggers associated with the
1729  *	event, and enables the event trigger itself, after
1730  *	initializing it (via the event_trigger_ops @init() function).
1731  *	This is also where commands can use the @trigger_type value to
1732  *	make the decision as to whether or not multiple instances of
1733  *	the trigger should be allowed.  This is usually implemented by
1734  *	the generic utility function @register_trigger() (see
1735  *	trace_event_triggers.c).
1736  *
1737  * @unreg: Removes the trigger from the list of triggers associated
1738  *	with the event, and disables the event trigger itself, after
1739  *	initializing it (via the event_trigger_ops @free() function).
1740  *	This is usually implemented by the generic utility function
1741  *	@unregister_trigger() (see trace_event_triggers.c).
1742  *
1743  * @unreg_all: An optional function called to remove all the triggers
1744  *	from the list of triggers associated with the event.  Called
1745  *	when a trigger file is opened in truncate mode.
1746  *
1747  * @set_filter: An optional function called to parse and set a filter
1748  *	for the trigger.  If no @set_filter() method is set for the
1749  *	event command, filters set by the user for the command will be
1750  *	ignored.  This is usually implemented by the generic utility
1751  *	function @set_trigger_filter() (see trace_event_triggers.c).
1752  *
1753  * @get_trigger_ops: The callback function invoked to retrieve the
1754  *	event_trigger_ops implementation associated with the command.
1755  *	This callback function allows a single event_command to
1756  *	support multiple trigger implementations via different sets of
1757  *	event_trigger_ops, depending on the value of the @param
1758  *	string.
1759  */
1760 struct event_command {
1761 	struct list_head	list;
1762 	char			*name;
1763 	enum event_trigger_type	trigger_type;
1764 	int			flags;
1765 	int			(*parse)(struct event_command *cmd_ops,
1766 					 struct trace_event_file *file,
1767 					 char *glob, char *cmd,
1768 					 char *param_and_filter);
1769 	int			(*reg)(char *glob,
1770 				       struct event_trigger_data *data,
1771 				       struct trace_event_file *file);
1772 	void			(*unreg)(char *glob,
1773 					 struct event_trigger_data *data,
1774 					 struct trace_event_file *file);
1775 	void			(*unreg_all)(struct trace_event_file *file);
1776 	int			(*set_filter)(char *filter_str,
1777 					      struct event_trigger_data *data,
1778 					      struct trace_event_file *file);
1779 	struct event_trigger_ops *(*get_trigger_ops)(char *cmd, char *param);
1780 };
1781 
1782 /**
1783  * enum event_command_flags - flags for struct event_command
1784  *
1785  * @POST_TRIGGER: A flag that says whether or not this command needs
1786  *	to have its action delayed until after the current event has
1787  *	been closed.  Some triggers need to avoid being invoked while
1788  *	an event is currently in the process of being logged, since
1789  *	the trigger may itself log data into the trace buffer.  Thus
1790  *	we make sure the current event is committed before invoking
1791  *	those triggers.  To do that, the trigger invocation is split
1792  *	in two - the first part checks the filter using the current
1793  *	trace record; if a command has the @post_trigger flag set, it
1794  *	sets a bit for itself in the return value, otherwise it
1795  *	directly invokes the trigger.  Once all commands have been
1796  *	either invoked or set their return flag, the current record is
1797  *	either committed or discarded.  At that point, if any commands
1798  *	have deferred their triggers, those commands are finally
1799  *	invoked following the close of the current event.  In other
1800  *	words, if the event_trigger_ops @func() probe implementation
1801  *	itself logs to the trace buffer, this flag should be set,
1802  *	otherwise it can be left unspecified.
1803  *
1804  * @NEEDS_REC: A flag that says whether or not this command needs
1805  *	access to the trace record in order to perform its function,
1806  *	regardless of whether or not it has a filter associated with
1807  *	it (filters make a trigger require access to the trace record
1808  *	but are not always present).
1809  */
1810 enum event_command_flags {
1811 	EVENT_CMD_FL_POST_TRIGGER	= 1,
1812 	EVENT_CMD_FL_NEEDS_REC		= 2,
1813 };
1814 
1815 static inline bool event_command_post_trigger(struct event_command *cmd_ops)
1816 {
1817 	return cmd_ops->flags & EVENT_CMD_FL_POST_TRIGGER;
1818 }
1819 
1820 static inline bool event_command_needs_rec(struct event_command *cmd_ops)
1821 {
1822 	return cmd_ops->flags & EVENT_CMD_FL_NEEDS_REC;
1823 }
1824 
1825 extern int trace_event_enable_disable(struct trace_event_file *file,
1826 				      int enable, int soft_disable);
1827 extern int tracing_alloc_snapshot(void);
1828 extern void tracing_snapshot_cond(struct trace_array *tr, void *cond_data);
1829 extern int tracing_snapshot_cond_enable(struct trace_array *tr, void *cond_data, cond_update_fn_t update);
1830 
1831 extern int tracing_snapshot_cond_disable(struct trace_array *tr);
1832 extern void *tracing_cond_snapshot_data(struct trace_array *tr);
1833 
1834 extern const char *__start___trace_bprintk_fmt[];
1835 extern const char *__stop___trace_bprintk_fmt[];
1836 
1837 extern const char *__start___tracepoint_str[];
1838 extern const char *__stop___tracepoint_str[];
1839 
1840 void trace_printk_control(bool enabled);
1841 void trace_printk_start_comm(void);
1842 int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set);
1843 int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled);
1844 
1845 /* Used from boot time tracer */
1846 extern int trace_set_options(struct trace_array *tr, char *option);
1847 extern int tracing_set_tracer(struct trace_array *tr, const char *buf);
1848 extern ssize_t tracing_resize_ring_buffer(struct trace_array *tr,
1849 					  unsigned long size, int cpu_id);
1850 extern int tracing_set_cpumask(struct trace_array *tr,
1851 				cpumask_var_t tracing_cpumask_new);
1852 
1853 
1854 #define MAX_EVENT_NAME_LEN	64
1855 
1856 extern ssize_t trace_parse_run_command(struct file *file,
1857 		const char __user *buffer, size_t count, loff_t *ppos,
1858 		int (*createfn)(const char *));
1859 
1860 extern unsigned int err_pos(char *cmd, const char *str);
1861 extern void tracing_log_err(struct trace_array *tr,
1862 			    const char *loc, const char *cmd,
1863 			    const char **errs, u8 type, u16 pos);
1864 
1865 /*
1866  * Normal trace_printk() and friends allocates special buffers
1867  * to do the manipulation, as well as saves the print formats
1868  * into sections to display. But the trace infrastructure wants
1869  * to use these without the added overhead at the price of being
1870  * a bit slower (used mainly for warnings, where we don't care
1871  * about performance). The internal_trace_puts() is for such
1872  * a purpose.
1873  */
1874 #define internal_trace_puts(str) __trace_puts(_THIS_IP_, str, strlen(str))
1875 
1876 #undef FTRACE_ENTRY
1877 #define FTRACE_ENTRY(call, struct_name, id, tstruct, print)	\
1878 	extern struct trace_event_call					\
1879 	__aligned(4) event_##call;
1880 #undef FTRACE_ENTRY_DUP
1881 #define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print)	\
1882 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
1883 #undef FTRACE_ENTRY_PACKED
1884 #define FTRACE_ENTRY_PACKED(call, struct_name, id, tstruct, print) \
1885 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
1886 
1887 #include "trace_entries.h"
1888 
1889 #if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_FUNCTION_TRACER)
1890 int perf_ftrace_event_register(struct trace_event_call *call,
1891 			       enum trace_reg type, void *data);
1892 #else
1893 #define perf_ftrace_event_register NULL
1894 #endif
1895 
1896 #ifdef CONFIG_FTRACE_SYSCALLS
1897 void init_ftrace_syscalls(void);
1898 const char *get_syscall_name(int syscall);
1899 #else
1900 static inline void init_ftrace_syscalls(void) { }
1901 static inline const char *get_syscall_name(int syscall)
1902 {
1903 	return NULL;
1904 }
1905 #endif
1906 
1907 #ifdef CONFIG_EVENT_TRACING
1908 void trace_event_init(void);
1909 void trace_event_eval_update(struct trace_eval_map **map, int len);
1910 /* Used from boot time tracer */
1911 extern int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set);
1912 extern int trigger_process_regex(struct trace_event_file *file, char *buff);
1913 #else
1914 static inline void __init trace_event_init(void) { }
1915 static inline void trace_event_eval_update(struct trace_eval_map **map, int len) { }
1916 #endif
1917 
1918 #ifdef CONFIG_TRACER_SNAPSHOT
1919 void tracing_snapshot_instance(struct trace_array *tr);
1920 int tracing_alloc_snapshot_instance(struct trace_array *tr);
1921 #else
1922 static inline void tracing_snapshot_instance(struct trace_array *tr) { }
1923 static inline int tracing_alloc_snapshot_instance(struct trace_array *tr)
1924 {
1925 	return 0;
1926 }
1927 #endif
1928 
1929 #ifdef CONFIG_PREEMPT_TRACER
1930 void tracer_preempt_on(unsigned long a0, unsigned long a1);
1931 void tracer_preempt_off(unsigned long a0, unsigned long a1);
1932 #else
1933 static inline void tracer_preempt_on(unsigned long a0, unsigned long a1) { }
1934 static inline void tracer_preempt_off(unsigned long a0, unsigned long a1) { }
1935 #endif
1936 #ifdef CONFIG_IRQSOFF_TRACER
1937 void tracer_hardirqs_on(unsigned long a0, unsigned long a1);
1938 void tracer_hardirqs_off(unsigned long a0, unsigned long a1);
1939 #else
1940 static inline void tracer_hardirqs_on(unsigned long a0, unsigned long a1) { }
1941 static inline void tracer_hardirqs_off(unsigned long a0, unsigned long a1) { }
1942 #endif
1943 
1944 extern struct trace_iterator *tracepoint_print_iter;
1945 
1946 /*
1947  * Reset the state of the trace_iterator so that it can read consumed data.
1948  * Normally, the trace_iterator is used for reading the data when it is not
1949  * consumed, and must retain state.
1950  */
1951 static __always_inline void trace_iterator_reset(struct trace_iterator *iter)
1952 {
1953 	memset_startat(iter, 0, seq);
1954 	iter->pos = -1;
1955 }
1956 
1957 /* Check the name is good for event/group/fields */
1958 static inline bool is_good_name(const char *name)
1959 {
1960 	if (!isalpha(*name) && *name != '_')
1961 		return false;
1962 	while (*++name != '\0') {
1963 		if (!isalpha(*name) && !isdigit(*name) && *name != '_')
1964 			return false;
1965 	}
1966 	return true;
1967 }
1968 
1969 /* Convert certain expected symbols into '_' when generating event names */
1970 static inline void sanitize_event_name(char *name)
1971 {
1972 	while (*name++ != '\0')
1973 		if (*name == ':' || *name == '.')
1974 			*name = '_';
1975 }
1976 
1977 /*
1978  * This is a generic way to read and write a u64 value from a file in tracefs.
1979  *
1980  * The value is stored on the variable pointed by *val. The value needs
1981  * to be at least *min and at most *max. The write is protected by an
1982  * existing *lock.
1983  */
1984 struct trace_min_max_param {
1985 	struct mutex	*lock;
1986 	u64		*val;
1987 	u64		*min;
1988 	u64		*max;
1989 };
1990 
1991 #define U64_STR_SIZE		24	/* 20 digits max */
1992 
1993 extern const struct file_operations trace_min_max_fops;
1994 
1995 #ifdef CONFIG_RV
1996 extern int rv_init_interface(void);
1997 #else
1998 static inline int rv_init_interface(void)
1999 {
2000 	return 0;
2001 }
2002 #endif
2003 
2004 #endif /* _LINUX_KERNEL_TRACE_H */
2005