xref: /openbmc/linux/kernel/trace/trace.h (revision cf41d18b)
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 #define HIST_STACKTRACE_DEPTH	16
117 #define HIST_STACKTRACE_SIZE	(HIST_STACKTRACE_DEPTH * sizeof(unsigned long))
118 #define HIST_STACKTRACE_SKIP	5
119 
120 /*
121  * syscalls are special, and need special handling, this is why
122  * they are not included in trace_entries.h
123  */
124 struct syscall_trace_enter {
125 	struct trace_entry	ent;
126 	int			nr;
127 	unsigned long		args[];
128 };
129 
130 struct syscall_trace_exit {
131 	struct trace_entry	ent;
132 	int			nr;
133 	long			ret;
134 };
135 
136 struct kprobe_trace_entry_head {
137 	struct trace_entry	ent;
138 	unsigned long		ip;
139 };
140 
141 struct eprobe_trace_entry_head {
142 	struct trace_entry	ent;
143 };
144 
145 struct kretprobe_trace_entry_head {
146 	struct trace_entry	ent;
147 	unsigned long		func;
148 	unsigned long		ret_ip;
149 };
150 
151 #define TRACE_BUF_SIZE		1024
152 
153 struct trace_array;
154 
155 /*
156  * The CPU trace array - it consists of thousands of trace entries
157  * plus some other descriptor data: (for example which task started
158  * the trace, etc.)
159  */
160 struct trace_array_cpu {
161 	atomic_t		disabled;
162 	void			*buffer_page;	/* ring buffer spare */
163 
164 	unsigned long		entries;
165 	unsigned long		saved_latency;
166 	unsigned long		critical_start;
167 	unsigned long		critical_end;
168 	unsigned long		critical_sequence;
169 	unsigned long		nice;
170 	unsigned long		policy;
171 	unsigned long		rt_priority;
172 	unsigned long		skipped_entries;
173 	u64			preempt_timestamp;
174 	pid_t			pid;
175 	kuid_t			uid;
176 	char			comm[TASK_COMM_LEN];
177 
178 #ifdef CONFIG_FUNCTION_TRACER
179 	int			ftrace_ignore_pid;
180 #endif
181 	bool			ignore_pid;
182 };
183 
184 struct tracer;
185 struct trace_option_dentry;
186 
187 struct array_buffer {
188 	struct trace_array		*tr;
189 	struct trace_buffer		*buffer;
190 	struct trace_array_cpu __percpu	*data;
191 	u64				time_start;
192 	int				cpu;
193 };
194 
195 #define TRACE_FLAGS_MAX_SIZE		32
196 
197 struct trace_options {
198 	struct tracer			*tracer;
199 	struct trace_option_dentry	*topts;
200 };
201 
202 struct trace_pid_list *trace_pid_list_alloc(void);
203 void trace_pid_list_free(struct trace_pid_list *pid_list);
204 bool trace_pid_list_is_set(struct trace_pid_list *pid_list, unsigned int pid);
205 int trace_pid_list_set(struct trace_pid_list *pid_list, unsigned int pid);
206 int trace_pid_list_clear(struct trace_pid_list *pid_list, unsigned int pid);
207 int trace_pid_list_first(struct trace_pid_list *pid_list, unsigned int *pid);
208 int trace_pid_list_next(struct trace_pid_list *pid_list, unsigned int pid,
209 			unsigned int *next);
210 
211 enum {
212 	TRACE_PIDS		= BIT(0),
213 	TRACE_NO_PIDS		= BIT(1),
214 };
215 
216 static inline bool pid_type_enabled(int type, struct trace_pid_list *pid_list,
217 				    struct trace_pid_list *no_pid_list)
218 {
219 	/* Return true if the pid list in type has pids */
220 	return ((type & TRACE_PIDS) && pid_list) ||
221 		((type & TRACE_NO_PIDS) && no_pid_list);
222 }
223 
224 static inline bool still_need_pid_events(int type, struct trace_pid_list *pid_list,
225 					 struct trace_pid_list *no_pid_list)
226 {
227 	/*
228 	 * Turning off what is in @type, return true if the "other"
229 	 * pid list, still has pids in it.
230 	 */
231 	return (!(type & TRACE_PIDS) && pid_list) ||
232 		(!(type & TRACE_NO_PIDS) && no_pid_list);
233 }
234 
235 typedef bool (*cond_update_fn_t)(struct trace_array *tr, void *cond_data);
236 
237 /**
238  * struct cond_snapshot - conditional snapshot data and callback
239  *
240  * The cond_snapshot structure encapsulates a callback function and
241  * data associated with the snapshot for a given tracing instance.
242  *
243  * When a snapshot is taken conditionally, by invoking
244  * tracing_snapshot_cond(tr, cond_data), the cond_data passed in is
245  * passed in turn to the cond_snapshot.update() function.  That data
246  * can be compared by the update() implementation with the cond_data
247  * contained within the struct cond_snapshot instance associated with
248  * the trace_array.  Because the tr->max_lock is held throughout the
249  * update() call, the update() function can directly retrieve the
250  * cond_snapshot and cond_data associated with the per-instance
251  * snapshot associated with the trace_array.
252  *
253  * The cond_snapshot.update() implementation can save data to be
254  * associated with the snapshot if it decides to, and returns 'true'
255  * in that case, or it returns 'false' if the conditional snapshot
256  * shouldn't be taken.
257  *
258  * The cond_snapshot instance is created and associated with the
259  * user-defined cond_data by tracing_cond_snapshot_enable().
260  * Likewise, the cond_snapshot instance is destroyed and is no longer
261  * associated with the trace instance by
262  * tracing_cond_snapshot_disable().
263  *
264  * The method below is required.
265  *
266  * @update: When a conditional snapshot is invoked, the update()
267  *	callback function is invoked with the tr->max_lock held.  The
268  *	update() implementation signals whether or not to actually
269  *	take the snapshot, by returning 'true' if so, 'false' if no
270  *	snapshot should be taken.  Because the max_lock is held for
271  *	the duration of update(), the implementation is safe to
272  *	directly retrieved and save any implementation data it needs
273  *	to in association with the snapshot.
274  */
275 struct cond_snapshot {
276 	void				*cond_data;
277 	cond_update_fn_t		update;
278 };
279 
280 /*
281  * struct trace_func_repeats - used to keep track of the consecutive
282  * (on the same CPU) calls of a single function.
283  */
284 struct trace_func_repeats {
285 	unsigned long	ip;
286 	unsigned long	parent_ip;
287 	unsigned long	count;
288 	u64		ts_last_call;
289 };
290 
291 /*
292  * The trace array - an array of per-CPU trace arrays. This is the
293  * highest level data structure that individual tracers deal with.
294  * They have on/off state as well:
295  */
296 struct trace_array {
297 	struct list_head	list;
298 	char			*name;
299 	struct array_buffer	array_buffer;
300 #ifdef CONFIG_TRACER_MAX_TRACE
301 	/*
302 	 * The max_buffer is used to snapshot the trace when a maximum
303 	 * latency is reached, or when the user initiates a snapshot.
304 	 * Some tracers will use this to store a maximum trace while
305 	 * it continues examining live traces.
306 	 *
307 	 * The buffers for the max_buffer are set up the same as the array_buffer
308 	 * When a snapshot is taken, the buffer of the max_buffer is swapped
309 	 * with the buffer of the array_buffer and the buffers are reset for
310 	 * the array_buffer so the tracing can continue.
311 	 */
312 	struct array_buffer	max_buffer;
313 	bool			allocated_snapshot;
314 #endif
315 #ifdef CONFIG_TRACER_MAX_TRACE
316 	unsigned long		max_latency;
317 #ifdef CONFIG_FSNOTIFY
318 	struct dentry		*d_max_latency;
319 	struct work_struct	fsnotify_work;
320 	struct irq_work		fsnotify_irqwork;
321 #endif
322 #endif
323 	struct trace_pid_list	__rcu *filtered_pids;
324 	struct trace_pid_list	__rcu *filtered_no_pids;
325 	/*
326 	 * max_lock is used to protect the swapping of buffers
327 	 * when taking a max snapshot. The buffers themselves are
328 	 * protected by per_cpu spinlocks. But the action of the swap
329 	 * needs its own lock.
330 	 *
331 	 * This is defined as a arch_spinlock_t in order to help
332 	 * with performance when lockdep debugging is enabled.
333 	 *
334 	 * It is also used in other places outside the update_max_tr
335 	 * so it needs to be defined outside of the
336 	 * CONFIG_TRACER_MAX_TRACE.
337 	 */
338 	arch_spinlock_t		max_lock;
339 	int			buffer_disabled;
340 #ifdef CONFIG_FTRACE_SYSCALLS
341 	int			sys_refcount_enter;
342 	int			sys_refcount_exit;
343 	struct trace_event_file __rcu *enter_syscall_files[NR_syscalls];
344 	struct trace_event_file __rcu *exit_syscall_files[NR_syscalls];
345 #endif
346 	int			stop_count;
347 	int			clock_id;
348 	int			nr_topts;
349 	bool			clear_trace;
350 	int			buffer_percent;
351 	unsigned int		n_err_log_entries;
352 	struct tracer		*current_trace;
353 	unsigned int		trace_flags;
354 	unsigned char		trace_flags_index[TRACE_FLAGS_MAX_SIZE];
355 	unsigned int		flags;
356 	raw_spinlock_t		start_lock;
357 	struct list_head	err_log;
358 	struct dentry		*dir;
359 	struct dentry		*options;
360 	struct dentry		*percpu_dir;
361 	struct dentry		*event_dir;
362 	struct trace_options	*topts;
363 	struct list_head	systems;
364 	struct list_head	events;
365 	struct trace_event_file *trace_marker_file;
366 	cpumask_var_t		tracing_cpumask; /* only trace on set CPUs */
367 	int			ref;
368 	int			trace_ref;
369 #ifdef CONFIG_FUNCTION_TRACER
370 	struct ftrace_ops	*ops;
371 	struct trace_pid_list	__rcu *function_pids;
372 	struct trace_pid_list	__rcu *function_no_pids;
373 #ifdef CONFIG_DYNAMIC_FTRACE
374 	/* All of these are protected by the ftrace_lock */
375 	struct list_head	func_probes;
376 	struct list_head	mod_trace;
377 	struct list_head	mod_notrace;
378 #endif
379 	/* function tracing enabled */
380 	int			function_enabled;
381 #endif
382 	int			no_filter_buffering_ref;
383 	struct list_head	hist_vars;
384 #ifdef CONFIG_TRACER_SNAPSHOT
385 	struct cond_snapshot	*cond_snapshot;
386 #endif
387 	struct trace_func_repeats	__percpu *last_func_repeats;
388 };
389 
390 enum {
391 	TRACE_ARRAY_FL_GLOBAL	= (1 << 0)
392 };
393 
394 extern struct list_head ftrace_trace_arrays;
395 
396 extern struct mutex trace_types_lock;
397 
398 extern int trace_array_get(struct trace_array *tr);
399 extern int tracing_check_open_get_tr(struct trace_array *tr);
400 extern struct trace_array *trace_array_find(const char *instance);
401 extern struct trace_array *trace_array_find_get(const char *instance);
402 
403 extern u64 tracing_event_time_stamp(struct trace_buffer *buffer, struct ring_buffer_event *rbe);
404 extern int tracing_set_filter_buffering(struct trace_array *tr, bool set);
405 extern int tracing_set_clock(struct trace_array *tr, const char *clockstr);
406 
407 extern bool trace_clock_in_ns(struct trace_array *tr);
408 
409 /*
410  * The global tracer (top) should be the first trace array added,
411  * but we check the flag anyway.
412  */
413 static inline struct trace_array *top_trace_array(void)
414 {
415 	struct trace_array *tr;
416 
417 	if (list_empty(&ftrace_trace_arrays))
418 		return NULL;
419 
420 	tr = list_entry(ftrace_trace_arrays.prev,
421 			typeof(*tr), list);
422 	WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
423 	return tr;
424 }
425 
426 #define FTRACE_CMP_TYPE(var, type) \
427 	__builtin_types_compatible_p(typeof(var), type *)
428 
429 #undef IF_ASSIGN
430 #define IF_ASSIGN(var, entry, etype, id)			\
431 	if (FTRACE_CMP_TYPE(var, etype)) {			\
432 		var = (typeof(var))(entry);			\
433 		WARN_ON(id != 0 && (entry)->type != id);	\
434 		break;						\
435 	}
436 
437 /* Will cause compile errors if type is not found. */
438 extern void __ftrace_bad_type(void);
439 
440 /*
441  * The trace_assign_type is a verifier that the entry type is
442  * the same as the type being assigned. To add new types simply
443  * add a line with the following format:
444  *
445  * IF_ASSIGN(var, ent, type, id);
446  *
447  *  Where "type" is the trace type that includes the trace_entry
448  *  as the "ent" item. And "id" is the trace identifier that is
449  *  used in the trace_type enum.
450  *
451  *  If the type can have more than one id, then use zero.
452  */
453 #define trace_assign_type(var, ent)					\
454 	do {								\
455 		IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);	\
456 		IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);	\
457 		IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);	\
458 		IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
459 		IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);	\
460 		IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT);	\
461 		IF_ASSIGN(var, ent, struct bputs_entry, TRACE_BPUTS);	\
462 		IF_ASSIGN(var, ent, struct hwlat_entry, TRACE_HWLAT);	\
463 		IF_ASSIGN(var, ent, struct osnoise_entry, TRACE_OSNOISE);\
464 		IF_ASSIGN(var, ent, struct timerlat_entry, TRACE_TIMERLAT);\
465 		IF_ASSIGN(var, ent, struct raw_data_entry, TRACE_RAW_DATA);\
466 		IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,		\
467 			  TRACE_MMIO_RW);				\
468 		IF_ASSIGN(var, ent, struct trace_mmiotrace_map,		\
469 			  TRACE_MMIO_MAP);				\
470 		IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
471 		IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,	\
472 			  TRACE_GRAPH_ENT);		\
473 		IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,	\
474 			  TRACE_GRAPH_RET);		\
475 		IF_ASSIGN(var, ent, struct func_repeats_entry,		\
476 			  TRACE_FUNC_REPEATS);				\
477 		__ftrace_bad_type();					\
478 	} while (0)
479 
480 /*
481  * An option specific to a tracer. This is a boolean value.
482  * The bit is the bit index that sets its value on the
483  * flags value in struct tracer_flags.
484  */
485 struct tracer_opt {
486 	const char	*name; /* Will appear on the trace_options file */
487 	u32		bit; /* Mask assigned in val field in tracer_flags */
488 };
489 
490 /*
491  * The set of specific options for a tracer. Your tracer
492  * have to set the initial value of the flags val.
493  */
494 struct tracer_flags {
495 	u32			val;
496 	struct tracer_opt	*opts;
497 	struct tracer		*trace;
498 };
499 
500 /* Makes more easy to define a tracer opt */
501 #define TRACER_OPT(s, b)	.name = #s, .bit = b
502 
503 
504 struct trace_option_dentry {
505 	struct tracer_opt		*opt;
506 	struct tracer_flags		*flags;
507 	struct trace_array		*tr;
508 	struct dentry			*entry;
509 };
510 
511 /**
512  * struct tracer - a specific tracer and its callbacks to interact with tracefs
513  * @name: the name chosen to select it on the available_tracers file
514  * @init: called when one switches to this tracer (echo name > current_tracer)
515  * @reset: called when one switches to another tracer
516  * @start: called when tracing is unpaused (echo 1 > tracing_on)
517  * @stop: called when tracing is paused (echo 0 > tracing_on)
518  * @update_thresh: called when tracing_thresh is updated
519  * @open: called when the trace file is opened
520  * @pipe_open: called when the trace_pipe file is opened
521  * @close: called when the trace file is released
522  * @pipe_close: called when the trace_pipe file is released
523  * @read: override the default read callback on trace_pipe
524  * @splice_read: override the default splice_read callback on trace_pipe
525  * @selftest: selftest to run on boot (see trace_selftest.c)
526  * @print_headers: override the first lines that describe your columns
527  * @print_line: callback that prints a trace
528  * @set_flag: signals one of your private flags changed (trace_options file)
529  * @flags: your private flags
530  */
531 struct tracer {
532 	const char		*name;
533 	int			(*init)(struct trace_array *tr);
534 	void			(*reset)(struct trace_array *tr);
535 	void			(*start)(struct trace_array *tr);
536 	void			(*stop)(struct trace_array *tr);
537 	int			(*update_thresh)(struct trace_array *tr);
538 	void			(*open)(struct trace_iterator *iter);
539 	void			(*pipe_open)(struct trace_iterator *iter);
540 	void			(*close)(struct trace_iterator *iter);
541 	void			(*pipe_close)(struct trace_iterator *iter);
542 	ssize_t			(*read)(struct trace_iterator *iter,
543 					struct file *filp, char __user *ubuf,
544 					size_t cnt, loff_t *ppos);
545 	ssize_t			(*splice_read)(struct trace_iterator *iter,
546 					       struct file *filp,
547 					       loff_t *ppos,
548 					       struct pipe_inode_info *pipe,
549 					       size_t len,
550 					       unsigned int flags);
551 #ifdef CONFIG_FTRACE_STARTUP_TEST
552 	int			(*selftest)(struct tracer *trace,
553 					    struct trace_array *tr);
554 #endif
555 	void			(*print_header)(struct seq_file *m);
556 	enum print_line_t	(*print_line)(struct trace_iterator *iter);
557 	/* If you handled the flag setting, return 0 */
558 	int			(*set_flag)(struct trace_array *tr,
559 					    u32 old_flags, u32 bit, int set);
560 	/* Return 0 if OK with change, else return non-zero */
561 	int			(*flag_changed)(struct trace_array *tr,
562 						u32 mask, int set);
563 	struct tracer		*next;
564 	struct tracer_flags	*flags;
565 	int			enabled;
566 	bool			print_max;
567 	bool			allow_instances;
568 #ifdef CONFIG_TRACER_MAX_TRACE
569 	bool			use_max_tr;
570 #endif
571 	/* True if tracer cannot be enabled in kernel param */
572 	bool			noboot;
573 };
574 
575 static inline struct ring_buffer_iter *
576 trace_buffer_iter(struct trace_iterator *iter, int cpu)
577 {
578 	return iter->buffer_iter ? iter->buffer_iter[cpu] : NULL;
579 }
580 
581 int tracer_init(struct tracer *t, struct trace_array *tr);
582 int tracing_is_enabled(void);
583 void tracing_reset_online_cpus(struct array_buffer *buf);
584 void tracing_reset_current(int cpu);
585 void tracing_reset_all_online_cpus(void);
586 void tracing_reset_all_online_cpus_unlocked(void);
587 int tracing_open_generic(struct inode *inode, struct file *filp);
588 int tracing_open_generic_tr(struct inode *inode, struct file *filp);
589 bool tracing_is_disabled(void);
590 bool tracer_tracing_is_on(struct trace_array *tr);
591 void tracer_tracing_on(struct trace_array *tr);
592 void tracer_tracing_off(struct trace_array *tr);
593 struct dentry *trace_create_file(const char *name,
594 				 umode_t mode,
595 				 struct dentry *parent,
596 				 void *data,
597 				 const struct file_operations *fops);
598 
599 int tracing_init_dentry(void);
600 
601 struct ring_buffer_event;
602 
603 struct ring_buffer_event *
604 trace_buffer_lock_reserve(struct trace_buffer *buffer,
605 			  int type,
606 			  unsigned long len,
607 			  unsigned int trace_ctx);
608 
609 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
610 						struct trace_array_cpu *data);
611 
612 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
613 					  int *ent_cpu, u64 *ent_ts);
614 
615 void trace_buffer_unlock_commit_nostack(struct trace_buffer *buffer,
616 					struct ring_buffer_event *event);
617 
618 bool trace_is_tracepoint_string(const char *str);
619 const char *trace_event_format(struct trace_iterator *iter, const char *fmt);
620 void trace_check_vprintf(struct trace_iterator *iter, const char *fmt,
621 			 va_list ap) __printf(2, 0);
622 
623 int trace_empty(struct trace_iterator *iter);
624 
625 void *trace_find_next_entry_inc(struct trace_iterator *iter);
626 
627 void trace_init_global_iter(struct trace_iterator *iter);
628 
629 void tracing_iter_reset(struct trace_iterator *iter, int cpu);
630 
631 unsigned long trace_total_entries_cpu(struct trace_array *tr, int cpu);
632 unsigned long trace_total_entries(struct trace_array *tr);
633 
634 void trace_function(struct trace_array *tr,
635 		    unsigned long ip,
636 		    unsigned long parent_ip,
637 		    unsigned int trace_ctx);
638 void trace_graph_function(struct trace_array *tr,
639 		    unsigned long ip,
640 		    unsigned long parent_ip,
641 		    unsigned int trace_ctx);
642 void trace_latency_header(struct seq_file *m);
643 void trace_default_header(struct seq_file *m);
644 void print_trace_header(struct seq_file *m, struct trace_iterator *iter);
645 
646 void trace_graph_return(struct ftrace_graph_ret *trace);
647 int trace_graph_entry(struct ftrace_graph_ent *trace);
648 void set_graph_array(struct trace_array *tr);
649 
650 void tracing_start_cmdline_record(void);
651 void tracing_stop_cmdline_record(void);
652 void tracing_start_tgid_record(void);
653 void tracing_stop_tgid_record(void);
654 
655 int register_tracer(struct tracer *type);
656 int is_tracing_stopped(void);
657 
658 loff_t tracing_lseek(struct file *file, loff_t offset, int whence);
659 
660 extern cpumask_var_t __read_mostly tracing_buffer_mask;
661 
662 #define for_each_tracing_cpu(cpu)	\
663 	for_each_cpu(cpu, tracing_buffer_mask)
664 
665 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
666 
667 extern unsigned long tracing_thresh;
668 
669 /* PID filtering */
670 
671 extern int pid_max;
672 
673 bool trace_find_filtered_pid(struct trace_pid_list *filtered_pids,
674 			     pid_t search_pid);
675 bool trace_ignore_this_task(struct trace_pid_list *filtered_pids,
676 			    struct trace_pid_list *filtered_no_pids,
677 			    struct task_struct *task);
678 void trace_filter_add_remove_task(struct trace_pid_list *pid_list,
679 				  struct task_struct *self,
680 				  struct task_struct *task);
681 void *trace_pid_next(struct trace_pid_list *pid_list, void *v, loff_t *pos);
682 void *trace_pid_start(struct trace_pid_list *pid_list, loff_t *pos);
683 int trace_pid_show(struct seq_file *m, void *v);
684 void trace_free_pid_list(struct trace_pid_list *pid_list);
685 int trace_pid_write(struct trace_pid_list *filtered_pids,
686 		    struct trace_pid_list **new_pid_list,
687 		    const char __user *ubuf, size_t cnt);
688 
689 #ifdef CONFIG_TRACER_MAX_TRACE
690 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu,
691 		   void *cond_data);
692 void update_max_tr_single(struct trace_array *tr,
693 			  struct task_struct *tsk, int cpu);
694 
695 #ifdef CONFIG_FSNOTIFY
696 #define LATENCY_FS_NOTIFY
697 #endif
698 #endif /* CONFIG_TRACER_MAX_TRACE */
699 
700 #ifdef LATENCY_FS_NOTIFY
701 void latency_fsnotify(struct trace_array *tr);
702 #else
703 static inline void latency_fsnotify(struct trace_array *tr) { }
704 #endif
705 
706 #ifdef CONFIG_STACKTRACE
707 void __trace_stack(struct trace_array *tr, unsigned int trace_ctx, int skip);
708 #else
709 static inline void __trace_stack(struct trace_array *tr, unsigned int trace_ctx,
710 				 int skip)
711 {
712 }
713 #endif /* CONFIG_STACKTRACE */
714 
715 void trace_last_func_repeats(struct trace_array *tr,
716 			     struct trace_func_repeats *last_info,
717 			     unsigned int trace_ctx);
718 
719 extern u64 ftrace_now(int cpu);
720 
721 extern void trace_find_cmdline(int pid, char comm[]);
722 extern int trace_find_tgid(int pid);
723 extern void trace_event_follow_fork(struct trace_array *tr, bool enable);
724 
725 #ifdef CONFIG_DYNAMIC_FTRACE
726 extern unsigned long ftrace_update_tot_cnt;
727 extern unsigned long ftrace_number_of_pages;
728 extern unsigned long ftrace_number_of_groups;
729 void ftrace_init_trace_array(struct trace_array *tr);
730 #else
731 static inline void ftrace_init_trace_array(struct trace_array *tr) { }
732 #endif
733 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
734 extern int DYN_FTRACE_TEST_NAME(void);
735 #define DYN_FTRACE_TEST_NAME2 trace_selftest_dynamic_test_func2
736 extern int DYN_FTRACE_TEST_NAME2(void);
737 
738 extern bool ring_buffer_expanded;
739 extern bool tracing_selftest_disabled;
740 
741 #ifdef CONFIG_FTRACE_STARTUP_TEST
742 extern void __init disable_tracing_selftest(const char *reason);
743 
744 extern int trace_selftest_startup_function(struct tracer *trace,
745 					   struct trace_array *tr);
746 extern int trace_selftest_startup_function_graph(struct tracer *trace,
747 						 struct trace_array *tr);
748 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
749 					  struct trace_array *tr);
750 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
751 					     struct trace_array *tr);
752 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
753 						 struct trace_array *tr);
754 extern int trace_selftest_startup_wakeup(struct tracer *trace,
755 					 struct trace_array *tr);
756 extern int trace_selftest_startup_nop(struct tracer *trace,
757 					 struct trace_array *tr);
758 extern int trace_selftest_startup_branch(struct tracer *trace,
759 					 struct trace_array *tr);
760 /*
761  * Tracer data references selftest functions that only occur
762  * on boot up. These can be __init functions. Thus, when selftests
763  * are enabled, then the tracers need to reference __init functions.
764  */
765 #define __tracer_data		__refdata
766 #else
767 static inline void __init disable_tracing_selftest(const char *reason)
768 {
769 }
770 /* Tracers are seldom changed. Optimize when selftests are disabled. */
771 #define __tracer_data		__read_mostly
772 #endif /* CONFIG_FTRACE_STARTUP_TEST */
773 
774 extern void *head_page(struct trace_array_cpu *data);
775 extern unsigned long long ns2usecs(u64 nsec);
776 extern int
777 trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
778 extern int
779 trace_vprintk(unsigned long ip, const char *fmt, va_list args);
780 extern int
781 trace_array_vprintk(struct trace_array *tr,
782 		    unsigned long ip, const char *fmt, va_list args);
783 int trace_array_printk_buf(struct trace_buffer *buffer,
784 			   unsigned long ip, const char *fmt, ...);
785 void trace_printk_seq(struct trace_seq *s);
786 enum print_line_t print_trace_line(struct trace_iterator *iter);
787 
788 extern char trace_find_mark(unsigned long long duration);
789 
790 struct ftrace_hash;
791 
792 struct ftrace_mod_load {
793 	struct list_head	list;
794 	char			*func;
795 	char			*module;
796 	int			 enable;
797 };
798 
799 enum {
800 	FTRACE_HASH_FL_MOD	= (1 << 0),
801 };
802 
803 struct ftrace_hash {
804 	unsigned long		size_bits;
805 	struct hlist_head	*buckets;
806 	unsigned long		count;
807 	unsigned long		flags;
808 	struct rcu_head		rcu;
809 };
810 
811 struct ftrace_func_entry *
812 ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip);
813 
814 static __always_inline bool ftrace_hash_empty(struct ftrace_hash *hash)
815 {
816 	return !hash || !(hash->count || (hash->flags & FTRACE_HASH_FL_MOD));
817 }
818 
819 /* Standard output formatting function used for function return traces */
820 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
821 
822 /* Flag options */
823 #define TRACE_GRAPH_PRINT_OVERRUN       0x1
824 #define TRACE_GRAPH_PRINT_CPU           0x2
825 #define TRACE_GRAPH_PRINT_OVERHEAD      0x4
826 #define TRACE_GRAPH_PRINT_PROC          0x8
827 #define TRACE_GRAPH_PRINT_DURATION      0x10
828 #define TRACE_GRAPH_PRINT_ABS_TIME      0x20
829 #define TRACE_GRAPH_PRINT_REL_TIME      0x40
830 #define TRACE_GRAPH_PRINT_IRQS          0x80
831 #define TRACE_GRAPH_PRINT_TAIL          0x100
832 #define TRACE_GRAPH_SLEEP_TIME          0x200
833 #define TRACE_GRAPH_GRAPH_TIME          0x400
834 #define TRACE_GRAPH_PRINT_FILL_SHIFT	28
835 #define TRACE_GRAPH_PRINT_FILL_MASK	(0x3 << TRACE_GRAPH_PRINT_FILL_SHIFT)
836 
837 extern void ftrace_graph_sleep_time_control(bool enable);
838 
839 #ifdef CONFIG_FUNCTION_PROFILER
840 extern void ftrace_graph_graph_time_control(bool enable);
841 #else
842 static inline void ftrace_graph_graph_time_control(bool enable) { }
843 #endif
844 
845 extern enum print_line_t
846 print_graph_function_flags(struct trace_iterator *iter, u32 flags);
847 extern void print_graph_headers_flags(struct seq_file *s, u32 flags);
848 extern void
849 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
850 extern void graph_trace_open(struct trace_iterator *iter);
851 extern void graph_trace_close(struct trace_iterator *iter);
852 extern int __trace_graph_entry(struct trace_array *tr,
853 			       struct ftrace_graph_ent *trace,
854 			       unsigned int trace_ctx);
855 extern void __trace_graph_return(struct trace_array *tr,
856 				 struct ftrace_graph_ret *trace,
857 				 unsigned int trace_ctx);
858 
859 #ifdef CONFIG_DYNAMIC_FTRACE
860 extern struct ftrace_hash __rcu *ftrace_graph_hash;
861 extern struct ftrace_hash __rcu *ftrace_graph_notrace_hash;
862 
863 static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace)
864 {
865 	unsigned long addr = trace->func;
866 	int ret = 0;
867 	struct ftrace_hash *hash;
868 
869 	preempt_disable_notrace();
870 
871 	/*
872 	 * Have to open code "rcu_dereference_sched()" because the
873 	 * function graph tracer can be called when RCU is not
874 	 * "watching".
875 	 * Protected with schedule_on_each_cpu(ftrace_sync)
876 	 */
877 	hash = rcu_dereference_protected(ftrace_graph_hash, !preemptible());
878 
879 	if (ftrace_hash_empty(hash)) {
880 		ret = 1;
881 		goto out;
882 	}
883 
884 	if (ftrace_lookup_ip(hash, addr)) {
885 
886 		/*
887 		 * This needs to be cleared on the return functions
888 		 * when the depth is zero.
889 		 */
890 		trace_recursion_set(TRACE_GRAPH_BIT);
891 		trace_recursion_set_depth(trace->depth);
892 
893 		/*
894 		 * If no irqs are to be traced, but a set_graph_function
895 		 * is set, and called by an interrupt handler, we still
896 		 * want to trace it.
897 		 */
898 		if (in_hardirq())
899 			trace_recursion_set(TRACE_IRQ_BIT);
900 		else
901 			trace_recursion_clear(TRACE_IRQ_BIT);
902 		ret = 1;
903 	}
904 
905 out:
906 	preempt_enable_notrace();
907 	return ret;
908 }
909 
910 static inline void ftrace_graph_addr_finish(struct ftrace_graph_ret *trace)
911 {
912 	if (trace_recursion_test(TRACE_GRAPH_BIT) &&
913 	    trace->depth == trace_recursion_depth())
914 		trace_recursion_clear(TRACE_GRAPH_BIT);
915 }
916 
917 static inline int ftrace_graph_notrace_addr(unsigned long addr)
918 {
919 	int ret = 0;
920 	struct ftrace_hash *notrace_hash;
921 
922 	preempt_disable_notrace();
923 
924 	/*
925 	 * Have to open code "rcu_dereference_sched()" because the
926 	 * function graph tracer can be called when RCU is not
927 	 * "watching".
928 	 * Protected with schedule_on_each_cpu(ftrace_sync)
929 	 */
930 	notrace_hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
931 						 !preemptible());
932 
933 	if (ftrace_lookup_ip(notrace_hash, addr))
934 		ret = 1;
935 
936 	preempt_enable_notrace();
937 	return ret;
938 }
939 #else
940 static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace)
941 {
942 	return 1;
943 }
944 
945 static inline int ftrace_graph_notrace_addr(unsigned long addr)
946 {
947 	return 0;
948 }
949 static inline void ftrace_graph_addr_finish(struct ftrace_graph_ret *trace)
950 { }
951 #endif /* CONFIG_DYNAMIC_FTRACE */
952 
953 extern unsigned int fgraph_max_depth;
954 
955 static inline bool ftrace_graph_ignore_func(struct ftrace_graph_ent *trace)
956 {
957 	/* trace it when it is-nested-in or is a function enabled. */
958 	return !(trace_recursion_test(TRACE_GRAPH_BIT) ||
959 		 ftrace_graph_addr(trace)) ||
960 		(trace->depth < 0) ||
961 		(fgraph_max_depth && trace->depth >= fgraph_max_depth);
962 }
963 
964 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
965 static inline enum print_line_t
966 print_graph_function_flags(struct trace_iterator *iter, u32 flags)
967 {
968 	return TRACE_TYPE_UNHANDLED;
969 }
970 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
971 
972 extern struct list_head ftrace_pids;
973 
974 #ifdef CONFIG_FUNCTION_TRACER
975 
976 #define FTRACE_PID_IGNORE	-1
977 #define FTRACE_PID_TRACE	-2
978 
979 struct ftrace_func_command {
980 	struct list_head	list;
981 	char			*name;
982 	int			(*func)(struct trace_array *tr,
983 					struct ftrace_hash *hash,
984 					char *func, char *cmd,
985 					char *params, int enable);
986 };
987 extern bool ftrace_filter_param __initdata;
988 static inline int ftrace_trace_task(struct trace_array *tr)
989 {
990 	return this_cpu_read(tr->array_buffer.data->ftrace_ignore_pid) !=
991 		FTRACE_PID_IGNORE;
992 }
993 extern int ftrace_is_dead(void);
994 int ftrace_create_function_files(struct trace_array *tr,
995 				 struct dentry *parent);
996 void ftrace_destroy_function_files(struct trace_array *tr);
997 int ftrace_allocate_ftrace_ops(struct trace_array *tr);
998 void ftrace_free_ftrace_ops(struct trace_array *tr);
999 void ftrace_init_global_array_ops(struct trace_array *tr);
1000 void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func);
1001 void ftrace_reset_array_ops(struct trace_array *tr);
1002 void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer);
1003 void ftrace_init_tracefs_toplevel(struct trace_array *tr,
1004 				  struct dentry *d_tracer);
1005 void ftrace_clear_pids(struct trace_array *tr);
1006 int init_function_trace(void);
1007 void ftrace_pid_follow_fork(struct trace_array *tr, bool enable);
1008 #else
1009 static inline int ftrace_trace_task(struct trace_array *tr)
1010 {
1011 	return 1;
1012 }
1013 static inline int ftrace_is_dead(void) { return 0; }
1014 static inline int
1015 ftrace_create_function_files(struct trace_array *tr,
1016 			     struct dentry *parent)
1017 {
1018 	return 0;
1019 }
1020 static inline int ftrace_allocate_ftrace_ops(struct trace_array *tr)
1021 {
1022 	return 0;
1023 }
1024 static inline void ftrace_free_ftrace_ops(struct trace_array *tr) { }
1025 static inline void ftrace_destroy_function_files(struct trace_array *tr) { }
1026 static inline __init void
1027 ftrace_init_global_array_ops(struct trace_array *tr) { }
1028 static inline void ftrace_reset_array_ops(struct trace_array *tr) { }
1029 static inline void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d) { }
1030 static inline void ftrace_init_tracefs_toplevel(struct trace_array *tr, struct dentry *d) { }
1031 static inline void ftrace_clear_pids(struct trace_array *tr) { }
1032 static inline int init_function_trace(void) { return 0; }
1033 static inline void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) { }
1034 /* ftace_func_t type is not defined, use macro instead of static inline */
1035 #define ftrace_init_array_ops(tr, func) do { } while (0)
1036 #endif /* CONFIG_FUNCTION_TRACER */
1037 
1038 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
1039 
1040 struct ftrace_probe_ops {
1041 	void			(*func)(unsigned long ip,
1042 					unsigned long parent_ip,
1043 					struct trace_array *tr,
1044 					struct ftrace_probe_ops *ops,
1045 					void *data);
1046 	int			(*init)(struct ftrace_probe_ops *ops,
1047 					struct trace_array *tr,
1048 					unsigned long ip, void *init_data,
1049 					void **data);
1050 	void			(*free)(struct ftrace_probe_ops *ops,
1051 					struct trace_array *tr,
1052 					unsigned long ip, void *data);
1053 	int			(*print)(struct seq_file *m,
1054 					 unsigned long ip,
1055 					 struct ftrace_probe_ops *ops,
1056 					 void *data);
1057 };
1058 
1059 struct ftrace_func_mapper;
1060 typedef int (*ftrace_mapper_func)(void *data);
1061 
1062 struct ftrace_func_mapper *allocate_ftrace_func_mapper(void);
1063 void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
1064 					   unsigned long ip);
1065 int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
1066 			       unsigned long ip, void *data);
1067 void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
1068 				   unsigned long ip);
1069 void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
1070 			     ftrace_mapper_func free_func);
1071 
1072 extern int
1073 register_ftrace_function_probe(char *glob, struct trace_array *tr,
1074 			       struct ftrace_probe_ops *ops, void *data);
1075 extern int
1076 unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
1077 				      struct ftrace_probe_ops *ops);
1078 extern void clear_ftrace_function_probes(struct trace_array *tr);
1079 
1080 int register_ftrace_command(struct ftrace_func_command *cmd);
1081 int unregister_ftrace_command(struct ftrace_func_command *cmd);
1082 
1083 void ftrace_create_filter_files(struct ftrace_ops *ops,
1084 				struct dentry *parent);
1085 void ftrace_destroy_filter_files(struct ftrace_ops *ops);
1086 
1087 extern int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
1088 			     int len, int reset);
1089 extern int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
1090 			      int len, int reset);
1091 #else
1092 struct ftrace_func_command;
1093 
1094 static inline __init int register_ftrace_command(struct ftrace_func_command *cmd)
1095 {
1096 	return -EINVAL;
1097 }
1098 static inline __init int unregister_ftrace_command(char *cmd_name)
1099 {
1100 	return -EINVAL;
1101 }
1102 static inline void clear_ftrace_function_probes(struct trace_array *tr)
1103 {
1104 }
1105 
1106 /*
1107  * The ops parameter passed in is usually undefined.
1108  * This must be a macro.
1109  */
1110 #define ftrace_create_filter_files(ops, parent) do { } while (0)
1111 #define ftrace_destroy_filter_files(ops) do { } while (0)
1112 #endif /* CONFIG_FUNCTION_TRACER && CONFIG_DYNAMIC_FTRACE */
1113 
1114 bool ftrace_event_is_function(struct trace_event_call *call);
1115 
1116 /*
1117  * struct trace_parser - servers for reading the user input separated by spaces
1118  * @cont: set if the input is not complete - no final space char was found
1119  * @buffer: holds the parsed user input
1120  * @idx: user input length
1121  * @size: buffer size
1122  */
1123 struct trace_parser {
1124 	bool		cont;
1125 	char		*buffer;
1126 	unsigned	idx;
1127 	unsigned	size;
1128 };
1129 
1130 static inline bool trace_parser_loaded(struct trace_parser *parser)
1131 {
1132 	return (parser->idx != 0);
1133 }
1134 
1135 static inline bool trace_parser_cont(struct trace_parser *parser)
1136 {
1137 	return parser->cont;
1138 }
1139 
1140 static inline void trace_parser_clear(struct trace_parser *parser)
1141 {
1142 	parser->cont = false;
1143 	parser->idx = 0;
1144 }
1145 
1146 extern int trace_parser_get_init(struct trace_parser *parser, int size);
1147 extern void trace_parser_put(struct trace_parser *parser);
1148 extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
1149 	size_t cnt, loff_t *ppos);
1150 
1151 /*
1152  * Only create function graph options if function graph is configured.
1153  */
1154 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1155 # define FGRAPH_FLAGS						\
1156 		C(DISPLAY_GRAPH,	"display-graph"),
1157 #else
1158 # define FGRAPH_FLAGS
1159 #endif
1160 
1161 #ifdef CONFIG_BRANCH_TRACER
1162 # define BRANCH_FLAGS					\
1163 		C(BRANCH,		"branch"),
1164 #else
1165 # define BRANCH_FLAGS
1166 #endif
1167 
1168 #ifdef CONFIG_FUNCTION_TRACER
1169 # define FUNCTION_FLAGS						\
1170 		C(FUNCTION,		"function-trace"),	\
1171 		C(FUNC_FORK,		"function-fork"),
1172 # define FUNCTION_DEFAULT_FLAGS		TRACE_ITER_FUNCTION
1173 #else
1174 # define FUNCTION_FLAGS
1175 # define FUNCTION_DEFAULT_FLAGS		0UL
1176 # define TRACE_ITER_FUNC_FORK		0UL
1177 #endif
1178 
1179 #ifdef CONFIG_STACKTRACE
1180 # define STACK_FLAGS				\
1181 		C(STACKTRACE,		"stacktrace"),
1182 #else
1183 # define STACK_FLAGS
1184 #endif
1185 
1186 /*
1187  * trace_iterator_flags is an enumeration that defines bit
1188  * positions into trace_flags that controls the output.
1189  *
1190  * NOTE: These bits must match the trace_options array in
1191  *       trace.c (this macro guarantees it).
1192  */
1193 #define TRACE_FLAGS						\
1194 		C(PRINT_PARENT,		"print-parent"),	\
1195 		C(SYM_OFFSET,		"sym-offset"),		\
1196 		C(SYM_ADDR,		"sym-addr"),		\
1197 		C(VERBOSE,		"verbose"),		\
1198 		C(RAW,			"raw"),			\
1199 		C(HEX,			"hex"),			\
1200 		C(BIN,			"bin"),			\
1201 		C(BLOCK,		"block"),		\
1202 		C(PRINTK,		"trace_printk"),	\
1203 		C(ANNOTATE,		"annotate"),		\
1204 		C(USERSTACKTRACE,	"userstacktrace"),	\
1205 		C(SYM_USEROBJ,		"sym-userobj"),		\
1206 		C(PRINTK_MSGONLY,	"printk-msg-only"),	\
1207 		C(CONTEXT_INFO,		"context-info"),   /* Print pid/cpu/time */ \
1208 		C(LATENCY_FMT,		"latency-format"),	\
1209 		C(RECORD_CMD,		"record-cmd"),		\
1210 		C(RECORD_TGID,		"record-tgid"),		\
1211 		C(OVERWRITE,		"overwrite"),		\
1212 		C(STOP_ON_FREE,		"disable_on_free"),	\
1213 		C(IRQ_INFO,		"irq-info"),		\
1214 		C(MARKERS,		"markers"),		\
1215 		C(EVENT_FORK,		"event-fork"),		\
1216 		C(PAUSE_ON_TRACE,	"pause-on-trace"),	\
1217 		C(HASH_PTR,		"hash-ptr"),	/* Print hashed pointer */ \
1218 		FUNCTION_FLAGS					\
1219 		FGRAPH_FLAGS					\
1220 		STACK_FLAGS					\
1221 		BRANCH_FLAGS
1222 
1223 /*
1224  * By defining C, we can make TRACE_FLAGS a list of bit names
1225  * that will define the bits for the flag masks.
1226  */
1227 #undef C
1228 #define C(a, b) TRACE_ITER_##a##_BIT
1229 
1230 enum trace_iterator_bits {
1231 	TRACE_FLAGS
1232 	/* Make sure we don't go more than we have bits for */
1233 	TRACE_ITER_LAST_BIT
1234 };
1235 
1236 /*
1237  * By redefining C, we can make TRACE_FLAGS a list of masks that
1238  * use the bits as defined above.
1239  */
1240 #undef C
1241 #define C(a, b) TRACE_ITER_##a = (1 << TRACE_ITER_##a##_BIT)
1242 
1243 enum trace_iterator_flags { TRACE_FLAGS };
1244 
1245 /*
1246  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
1247  * control the output of kernel symbols.
1248  */
1249 #define TRACE_ITER_SYM_MASK \
1250 	(TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
1251 
1252 extern struct tracer nop_trace;
1253 
1254 #ifdef CONFIG_BRANCH_TRACER
1255 extern int enable_branch_tracing(struct trace_array *tr);
1256 extern void disable_branch_tracing(void);
1257 static inline int trace_branch_enable(struct trace_array *tr)
1258 {
1259 	if (tr->trace_flags & TRACE_ITER_BRANCH)
1260 		return enable_branch_tracing(tr);
1261 	return 0;
1262 }
1263 static inline void trace_branch_disable(void)
1264 {
1265 	/* due to races, always disable */
1266 	disable_branch_tracing();
1267 }
1268 #else
1269 static inline int trace_branch_enable(struct trace_array *tr)
1270 {
1271 	return 0;
1272 }
1273 static inline void trace_branch_disable(void)
1274 {
1275 }
1276 #endif /* CONFIG_BRANCH_TRACER */
1277 
1278 /* set ring buffers to default size if not already done so */
1279 int tracing_update_buffers(void);
1280 
1281 struct ftrace_event_field {
1282 	struct list_head	link;
1283 	const char		*name;
1284 	const char		*type;
1285 	int			filter_type;
1286 	int			offset;
1287 	int			size;
1288 	int			is_signed;
1289 	int			len;
1290 };
1291 
1292 struct prog_entry;
1293 
1294 struct event_filter {
1295 	struct prog_entry __rcu	*prog;
1296 	char			*filter_string;
1297 };
1298 
1299 struct event_subsystem {
1300 	struct list_head	list;
1301 	const char		*name;
1302 	struct event_filter	*filter;
1303 	int			ref_count;
1304 };
1305 
1306 struct trace_subsystem_dir {
1307 	struct list_head		list;
1308 	struct event_subsystem		*subsystem;
1309 	struct trace_array		*tr;
1310 	struct dentry			*entry;
1311 	int				ref_count;
1312 	int				nr_events;
1313 };
1314 
1315 extern int call_filter_check_discard(struct trace_event_call *call, void *rec,
1316 				     struct trace_buffer *buffer,
1317 				     struct ring_buffer_event *event);
1318 
1319 void trace_buffer_unlock_commit_regs(struct trace_array *tr,
1320 				     struct trace_buffer *buffer,
1321 				     struct ring_buffer_event *event,
1322 				     unsigned int trcace_ctx,
1323 				     struct pt_regs *regs);
1324 
1325 static inline void trace_buffer_unlock_commit(struct trace_array *tr,
1326 					      struct trace_buffer *buffer,
1327 					      struct ring_buffer_event *event,
1328 					      unsigned int trace_ctx)
1329 {
1330 	trace_buffer_unlock_commit_regs(tr, buffer, event, trace_ctx, NULL);
1331 }
1332 
1333 DECLARE_PER_CPU(struct ring_buffer_event *, trace_buffered_event);
1334 DECLARE_PER_CPU(int, trace_buffered_event_cnt);
1335 void trace_buffered_event_disable(void);
1336 void trace_buffered_event_enable(void);
1337 
1338 void early_enable_events(struct trace_array *tr, char *buf, bool disable_first);
1339 
1340 static inline void
1341 __trace_event_discard_commit(struct trace_buffer *buffer,
1342 			     struct ring_buffer_event *event)
1343 {
1344 	if (this_cpu_read(trace_buffered_event) == event) {
1345 		/* Simply release the temp buffer and enable preemption */
1346 		this_cpu_dec(trace_buffered_event_cnt);
1347 		preempt_enable_notrace();
1348 		return;
1349 	}
1350 	/* ring_buffer_discard_commit() enables preemption */
1351 	ring_buffer_discard_commit(buffer, event);
1352 }
1353 
1354 /*
1355  * Helper function for event_trigger_unlock_commit{_regs}().
1356  * If there are event triggers attached to this event that requires
1357  * filtering against its fields, then they will be called as the
1358  * entry already holds the field information of the current event.
1359  *
1360  * It also checks if the event should be discarded or not.
1361  * It is to be discarded if the event is soft disabled and the
1362  * event was only recorded to process triggers, or if the event
1363  * filter is active and this event did not match the filters.
1364  *
1365  * Returns true if the event is discarded, false otherwise.
1366  */
1367 static inline bool
1368 __event_trigger_test_discard(struct trace_event_file *file,
1369 			     struct trace_buffer *buffer,
1370 			     struct ring_buffer_event *event,
1371 			     void *entry,
1372 			     enum event_trigger_type *tt)
1373 {
1374 	unsigned long eflags = file->flags;
1375 
1376 	if (eflags & EVENT_FILE_FL_TRIGGER_COND)
1377 		*tt = event_triggers_call(file, buffer, entry, event);
1378 
1379 	if (likely(!(file->flags & (EVENT_FILE_FL_SOFT_DISABLED |
1380 				    EVENT_FILE_FL_FILTERED |
1381 				    EVENT_FILE_FL_PID_FILTER))))
1382 		return false;
1383 
1384 	if (file->flags & EVENT_FILE_FL_SOFT_DISABLED)
1385 		goto discard;
1386 
1387 	if (file->flags & EVENT_FILE_FL_FILTERED &&
1388 	    !filter_match_preds(file->filter, entry))
1389 		goto discard;
1390 
1391 	if ((file->flags & EVENT_FILE_FL_PID_FILTER) &&
1392 	    trace_event_ignore_this_pid(file))
1393 		goto discard;
1394 
1395 	return false;
1396  discard:
1397 	__trace_event_discard_commit(buffer, event);
1398 	return true;
1399 }
1400 
1401 /**
1402  * event_trigger_unlock_commit - handle triggers and finish event commit
1403  * @file: The file pointer associated with the event
1404  * @buffer: The ring buffer that the event is being written to
1405  * @event: The event meta data in the ring buffer
1406  * @entry: The event itself
1407  * @trace_ctx: The tracing context flags.
1408  *
1409  * This is a helper function to handle triggers that require data
1410  * from the event itself. It also tests the event against filters and
1411  * if the event is soft disabled and should be discarded.
1412  */
1413 static inline void
1414 event_trigger_unlock_commit(struct trace_event_file *file,
1415 			    struct trace_buffer *buffer,
1416 			    struct ring_buffer_event *event,
1417 			    void *entry, unsigned int trace_ctx)
1418 {
1419 	enum event_trigger_type tt = ETT_NONE;
1420 
1421 	if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1422 		trace_buffer_unlock_commit(file->tr, buffer, event, trace_ctx);
1423 
1424 	if (tt)
1425 		event_triggers_post_call(file, tt);
1426 }
1427 
1428 #define FILTER_PRED_INVALID	((unsigned short)-1)
1429 #define FILTER_PRED_IS_RIGHT	(1 << 15)
1430 #define FILTER_PRED_FOLD	(1 << 15)
1431 
1432 /*
1433  * The max preds is the size of unsigned short with
1434  * two flags at the MSBs. One bit is used for both the IS_RIGHT
1435  * and FOLD flags. The other is reserved.
1436  *
1437  * 2^14 preds is way more than enough.
1438  */
1439 #define MAX_FILTER_PRED		16384
1440 
1441 struct filter_pred;
1442 struct regex;
1443 
1444 typedef int (*regex_match_func)(char *str, struct regex *r, int len);
1445 
1446 enum regex_type {
1447 	MATCH_FULL = 0,
1448 	MATCH_FRONT_ONLY,
1449 	MATCH_MIDDLE_ONLY,
1450 	MATCH_END_ONLY,
1451 	MATCH_GLOB,
1452 	MATCH_INDEX,
1453 };
1454 
1455 struct regex {
1456 	char			pattern[MAX_FILTER_STR_VAL];
1457 	int			len;
1458 	int			field_len;
1459 	regex_match_func	match;
1460 };
1461 
1462 static inline bool is_string_field(struct ftrace_event_field *field)
1463 {
1464 	return field->filter_type == FILTER_DYN_STRING ||
1465 	       field->filter_type == FILTER_RDYN_STRING ||
1466 	       field->filter_type == FILTER_STATIC_STRING ||
1467 	       field->filter_type == FILTER_PTR_STRING ||
1468 	       field->filter_type == FILTER_COMM;
1469 }
1470 
1471 static inline bool is_function_field(struct ftrace_event_field *field)
1472 {
1473 	return field->filter_type == FILTER_TRACE_FN;
1474 }
1475 
1476 extern enum regex_type
1477 filter_parse_regex(char *buff, int len, char **search, int *not);
1478 extern void print_event_filter(struct trace_event_file *file,
1479 			       struct trace_seq *s);
1480 extern int apply_event_filter(struct trace_event_file *file,
1481 			      char *filter_string);
1482 extern int apply_subsystem_event_filter(struct trace_subsystem_dir *dir,
1483 					char *filter_string);
1484 extern void print_subsystem_event_filter(struct event_subsystem *system,
1485 					 struct trace_seq *s);
1486 extern int filter_assign_type(const char *type);
1487 extern int create_event_filter(struct trace_array *tr,
1488 			       struct trace_event_call *call,
1489 			       char *filter_str, bool set_str,
1490 			       struct event_filter **filterp);
1491 extern void free_event_filter(struct event_filter *filter);
1492 
1493 struct ftrace_event_field *
1494 trace_find_event_field(struct trace_event_call *call, char *name);
1495 
1496 extern void trace_event_enable_cmd_record(bool enable);
1497 extern void trace_event_enable_tgid_record(bool enable);
1498 
1499 extern int event_trace_init(void);
1500 extern int init_events(void);
1501 extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
1502 extern int event_trace_del_tracer(struct trace_array *tr);
1503 extern void __trace_early_add_events(struct trace_array *tr);
1504 
1505 extern struct trace_event_file *__find_event_file(struct trace_array *tr,
1506 						  const char *system,
1507 						  const char *event);
1508 extern struct trace_event_file *find_event_file(struct trace_array *tr,
1509 						const char *system,
1510 						const char *event);
1511 
1512 static inline void *event_file_data(struct file *filp)
1513 {
1514 	return READ_ONCE(file_inode(filp)->i_private);
1515 }
1516 
1517 extern struct mutex event_mutex;
1518 extern struct list_head ftrace_events;
1519 
1520 extern const struct file_operations event_trigger_fops;
1521 extern const struct file_operations event_hist_fops;
1522 extern const struct file_operations event_hist_debug_fops;
1523 extern const struct file_operations event_inject_fops;
1524 
1525 #ifdef CONFIG_HIST_TRIGGERS
1526 extern int register_trigger_hist_cmd(void);
1527 extern int register_trigger_hist_enable_disable_cmds(void);
1528 #else
1529 static inline int register_trigger_hist_cmd(void) { return 0; }
1530 static inline int register_trigger_hist_enable_disable_cmds(void) { return 0; }
1531 #endif
1532 
1533 extern int register_trigger_cmds(void);
1534 extern void clear_event_triggers(struct trace_array *tr);
1535 
1536 enum {
1537 	EVENT_TRIGGER_FL_PROBE		= BIT(0),
1538 };
1539 
1540 struct event_trigger_data {
1541 	unsigned long			count;
1542 	int				ref;
1543 	int				flags;
1544 	struct event_trigger_ops	*ops;
1545 	struct event_command		*cmd_ops;
1546 	struct event_filter __rcu	*filter;
1547 	char				*filter_str;
1548 	void				*private_data;
1549 	bool				paused;
1550 	bool				paused_tmp;
1551 	struct list_head		list;
1552 	char				*name;
1553 	struct list_head		named_list;
1554 	struct event_trigger_data	*named_data;
1555 };
1556 
1557 /* Avoid typos */
1558 #define ENABLE_EVENT_STR	"enable_event"
1559 #define DISABLE_EVENT_STR	"disable_event"
1560 #define ENABLE_HIST_STR		"enable_hist"
1561 #define DISABLE_HIST_STR	"disable_hist"
1562 
1563 struct enable_trigger_data {
1564 	struct trace_event_file		*file;
1565 	bool				enable;
1566 	bool				hist;
1567 };
1568 
1569 extern int event_enable_trigger_print(struct seq_file *m,
1570 				      struct event_trigger_data *data);
1571 extern void event_enable_trigger_free(struct event_trigger_data *data);
1572 extern int event_enable_trigger_parse(struct event_command *cmd_ops,
1573 				      struct trace_event_file *file,
1574 				      char *glob, char *cmd,
1575 				      char *param_and_filter);
1576 extern int event_enable_register_trigger(char *glob,
1577 					 struct event_trigger_data *data,
1578 					 struct trace_event_file *file);
1579 extern void event_enable_unregister_trigger(char *glob,
1580 					    struct event_trigger_data *test,
1581 					    struct trace_event_file *file);
1582 extern void trigger_data_free(struct event_trigger_data *data);
1583 extern int event_trigger_init(struct event_trigger_data *data);
1584 extern int trace_event_trigger_enable_disable(struct trace_event_file *file,
1585 					      int trigger_enable);
1586 extern void update_cond_flag(struct trace_event_file *file);
1587 extern int set_trigger_filter(char *filter_str,
1588 			      struct event_trigger_data *trigger_data,
1589 			      struct trace_event_file *file);
1590 extern struct event_trigger_data *find_named_trigger(const char *name);
1591 extern bool is_named_trigger(struct event_trigger_data *test);
1592 extern int save_named_trigger(const char *name,
1593 			      struct event_trigger_data *data);
1594 extern void del_named_trigger(struct event_trigger_data *data);
1595 extern void pause_named_trigger(struct event_trigger_data *data);
1596 extern void unpause_named_trigger(struct event_trigger_data *data);
1597 extern void set_named_trigger_data(struct event_trigger_data *data,
1598 				   struct event_trigger_data *named_data);
1599 extern struct event_trigger_data *
1600 get_named_trigger_data(struct event_trigger_data *data);
1601 extern int register_event_command(struct event_command *cmd);
1602 extern int unregister_event_command(struct event_command *cmd);
1603 extern int register_trigger_hist_enable_disable_cmds(void);
1604 extern bool event_trigger_check_remove(const char *glob);
1605 extern bool event_trigger_empty_param(const char *param);
1606 extern int event_trigger_separate_filter(char *param_and_filter, char **param,
1607 					 char **filter, bool param_required);
1608 extern struct event_trigger_data *
1609 event_trigger_alloc(struct event_command *cmd_ops,
1610 		    char *cmd,
1611 		    char *param,
1612 		    void *private_data);
1613 extern int event_trigger_parse_num(char *trigger,
1614 				   struct event_trigger_data *trigger_data);
1615 extern int event_trigger_set_filter(struct event_command *cmd_ops,
1616 				    struct trace_event_file *file,
1617 				    char *param,
1618 				    struct event_trigger_data *trigger_data);
1619 extern void event_trigger_reset_filter(struct event_command *cmd_ops,
1620 				       struct event_trigger_data *trigger_data);
1621 extern int event_trigger_register(struct event_command *cmd_ops,
1622 				  struct trace_event_file *file,
1623 				  char *glob,
1624 				  struct event_trigger_data *trigger_data);
1625 extern void event_trigger_unregister(struct event_command *cmd_ops,
1626 				     struct trace_event_file *file,
1627 				     char *glob,
1628 				     struct event_trigger_data *trigger_data);
1629 
1630 /**
1631  * struct event_trigger_ops - callbacks for trace event triggers
1632  *
1633  * The methods in this structure provide per-event trigger hooks for
1634  * various trigger operations.
1635  *
1636  * The @init and @free methods are used during trigger setup and
1637  * teardown, typically called from an event_command's @parse()
1638  * function implementation.
1639  *
1640  * The @print method is used to print the trigger spec.
1641  *
1642  * The @trigger method is the function that actually implements the
1643  * trigger and is called in the context of the triggering event
1644  * whenever that event occurs.
1645  *
1646  * All the methods below, except for @init() and @free(), must be
1647  * implemented.
1648  *
1649  * @trigger: The trigger 'probe' function called when the triggering
1650  *	event occurs.  The data passed into this callback is the data
1651  *	that was supplied to the event_command @reg() function that
1652  *	registered the trigger (see struct event_command) along with
1653  *	the trace record, rec.
1654  *
1655  * @init: An optional initialization function called for the trigger
1656  *	when the trigger is registered (via the event_command reg()
1657  *	function).  This can be used to perform per-trigger
1658  *	initialization such as incrementing a per-trigger reference
1659  *	count, for instance.  This is usually implemented by the
1660  *	generic utility function @event_trigger_init() (see
1661  *	trace_event_triggers.c).
1662  *
1663  * @free: An optional de-initialization function called for the
1664  *	trigger when the trigger is unregistered (via the
1665  *	event_command @reg() function).  This can be used to perform
1666  *	per-trigger de-initialization such as decrementing a
1667  *	per-trigger reference count and freeing corresponding trigger
1668  *	data, for instance.  This is usually implemented by the
1669  *	generic utility function @event_trigger_free() (see
1670  *	trace_event_triggers.c).
1671  *
1672  * @print: The callback function invoked to have the trigger print
1673  *	itself.  This is usually implemented by a wrapper function
1674  *	that calls the generic utility function @event_trigger_print()
1675  *	(see trace_event_triggers.c).
1676  */
1677 struct event_trigger_ops {
1678 	void			(*trigger)(struct event_trigger_data *data,
1679 					   struct trace_buffer *buffer,
1680 					   void *rec,
1681 					   struct ring_buffer_event *rbe);
1682 	int			(*init)(struct event_trigger_data *data);
1683 	void			(*free)(struct event_trigger_data *data);
1684 	int			(*print)(struct seq_file *m,
1685 					 struct event_trigger_data *data);
1686 };
1687 
1688 /**
1689  * struct event_command - callbacks and data members for event commands
1690  *
1691  * Event commands are invoked by users by writing the command name
1692  * into the 'trigger' file associated with a trace event.  The
1693  * parameters associated with a specific invocation of an event
1694  * command are used to create an event trigger instance, which is
1695  * added to the list of trigger instances associated with that trace
1696  * event.  When the event is hit, the set of triggers associated with
1697  * that event is invoked.
1698  *
1699  * The data members in this structure provide per-event command data
1700  * for various event commands.
1701  *
1702  * All the data members below, except for @post_trigger, must be set
1703  * for each event command.
1704  *
1705  * @name: The unique name that identifies the event command.  This is
1706  *	the name used when setting triggers via trigger files.
1707  *
1708  * @trigger_type: A unique id that identifies the event command
1709  *	'type'.  This value has two purposes, the first to ensure that
1710  *	only one trigger of the same type can be set at a given time
1711  *	for a particular event e.g. it doesn't make sense to have both
1712  *	a traceon and traceoff trigger attached to a single event at
1713  *	the same time, so traceon and traceoff have the same type
1714  *	though they have different names.  The @trigger_type value is
1715  *	also used as a bit value for deferring the actual trigger
1716  *	action until after the current event is finished.  Some
1717  *	commands need to do this if they themselves log to the trace
1718  *	buffer (see the @post_trigger() member below).  @trigger_type
1719  *	values are defined by adding new values to the trigger_type
1720  *	enum in include/linux/trace_events.h.
1721  *
1722  * @flags: See the enum event_command_flags below.
1723  *
1724  * All the methods below, except for @set_filter() and @unreg_all(),
1725  * must be implemented.
1726  *
1727  * @parse: The callback function responsible for parsing and
1728  *	registering the trigger written to the 'trigger' file by the
1729  *	user.  It allocates the trigger instance and registers it with
1730  *	the appropriate trace event.  It makes use of the other
1731  *	event_command callback functions to orchestrate this, and is
1732  *	usually implemented by the generic utility function
1733  *	@event_trigger_callback() (see trace_event_triggers.c).
1734  *
1735  * @reg: Adds the trigger to the list of triggers associated with the
1736  *	event, and enables the event trigger itself, after
1737  *	initializing it (via the event_trigger_ops @init() function).
1738  *	This is also where commands can use the @trigger_type value to
1739  *	make the decision as to whether or not multiple instances of
1740  *	the trigger should be allowed.  This is usually implemented by
1741  *	the generic utility function @register_trigger() (see
1742  *	trace_event_triggers.c).
1743  *
1744  * @unreg: Removes the trigger from the list of triggers associated
1745  *	with the event, and disables the event trigger itself, after
1746  *	initializing it (via the event_trigger_ops @free() function).
1747  *	This is usually implemented by the generic utility function
1748  *	@unregister_trigger() (see trace_event_triggers.c).
1749  *
1750  * @unreg_all: An optional function called to remove all the triggers
1751  *	from the list of triggers associated with the event.  Called
1752  *	when a trigger file is opened in truncate mode.
1753  *
1754  * @set_filter: An optional function called to parse and set a filter
1755  *	for the trigger.  If no @set_filter() method is set for the
1756  *	event command, filters set by the user for the command will be
1757  *	ignored.  This is usually implemented by the generic utility
1758  *	function @set_trigger_filter() (see trace_event_triggers.c).
1759  *
1760  * @get_trigger_ops: The callback function invoked to retrieve the
1761  *	event_trigger_ops implementation associated with the command.
1762  *	This callback function allows a single event_command to
1763  *	support multiple trigger implementations via different sets of
1764  *	event_trigger_ops, depending on the value of the @param
1765  *	string.
1766  */
1767 struct event_command {
1768 	struct list_head	list;
1769 	char			*name;
1770 	enum event_trigger_type	trigger_type;
1771 	int			flags;
1772 	int			(*parse)(struct event_command *cmd_ops,
1773 					 struct trace_event_file *file,
1774 					 char *glob, char *cmd,
1775 					 char *param_and_filter);
1776 	int			(*reg)(char *glob,
1777 				       struct event_trigger_data *data,
1778 				       struct trace_event_file *file);
1779 	void			(*unreg)(char *glob,
1780 					 struct event_trigger_data *data,
1781 					 struct trace_event_file *file);
1782 	void			(*unreg_all)(struct trace_event_file *file);
1783 	int			(*set_filter)(char *filter_str,
1784 					      struct event_trigger_data *data,
1785 					      struct trace_event_file *file);
1786 	struct event_trigger_ops *(*get_trigger_ops)(char *cmd, char *param);
1787 };
1788 
1789 /**
1790  * enum event_command_flags - flags for struct event_command
1791  *
1792  * @POST_TRIGGER: A flag that says whether or not this command needs
1793  *	to have its action delayed until after the current event has
1794  *	been closed.  Some triggers need to avoid being invoked while
1795  *	an event is currently in the process of being logged, since
1796  *	the trigger may itself log data into the trace buffer.  Thus
1797  *	we make sure the current event is committed before invoking
1798  *	those triggers.  To do that, the trigger invocation is split
1799  *	in two - the first part checks the filter using the current
1800  *	trace record; if a command has the @post_trigger flag set, it
1801  *	sets a bit for itself in the return value, otherwise it
1802  *	directly invokes the trigger.  Once all commands have been
1803  *	either invoked or set their return flag, the current record is
1804  *	either committed or discarded.  At that point, if any commands
1805  *	have deferred their triggers, those commands are finally
1806  *	invoked following the close of the current event.  In other
1807  *	words, if the event_trigger_ops @func() probe implementation
1808  *	itself logs to the trace buffer, this flag should be set,
1809  *	otherwise it can be left unspecified.
1810  *
1811  * @NEEDS_REC: A flag that says whether or not this command needs
1812  *	access to the trace record in order to perform its function,
1813  *	regardless of whether or not it has a filter associated with
1814  *	it (filters make a trigger require access to the trace record
1815  *	but are not always present).
1816  */
1817 enum event_command_flags {
1818 	EVENT_CMD_FL_POST_TRIGGER	= 1,
1819 	EVENT_CMD_FL_NEEDS_REC		= 2,
1820 };
1821 
1822 static inline bool event_command_post_trigger(struct event_command *cmd_ops)
1823 {
1824 	return cmd_ops->flags & EVENT_CMD_FL_POST_TRIGGER;
1825 }
1826 
1827 static inline bool event_command_needs_rec(struct event_command *cmd_ops)
1828 {
1829 	return cmd_ops->flags & EVENT_CMD_FL_NEEDS_REC;
1830 }
1831 
1832 extern int trace_event_enable_disable(struct trace_event_file *file,
1833 				      int enable, int soft_disable);
1834 extern int tracing_alloc_snapshot(void);
1835 extern void tracing_snapshot_cond(struct trace_array *tr, void *cond_data);
1836 extern int tracing_snapshot_cond_enable(struct trace_array *tr, void *cond_data, cond_update_fn_t update);
1837 
1838 extern int tracing_snapshot_cond_disable(struct trace_array *tr);
1839 extern void *tracing_cond_snapshot_data(struct trace_array *tr);
1840 
1841 extern const char *__start___trace_bprintk_fmt[];
1842 extern const char *__stop___trace_bprintk_fmt[];
1843 
1844 extern const char *__start___tracepoint_str[];
1845 extern const char *__stop___tracepoint_str[];
1846 
1847 void trace_printk_control(bool enabled);
1848 void trace_printk_start_comm(void);
1849 int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set);
1850 int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled);
1851 
1852 /* Used from boot time tracer */
1853 extern int trace_set_options(struct trace_array *tr, char *option);
1854 extern int tracing_set_tracer(struct trace_array *tr, const char *buf);
1855 extern ssize_t tracing_resize_ring_buffer(struct trace_array *tr,
1856 					  unsigned long size, int cpu_id);
1857 extern int tracing_set_cpumask(struct trace_array *tr,
1858 				cpumask_var_t tracing_cpumask_new);
1859 
1860 
1861 #define MAX_EVENT_NAME_LEN	64
1862 
1863 extern ssize_t trace_parse_run_command(struct file *file,
1864 		const char __user *buffer, size_t count, loff_t *ppos,
1865 		int (*createfn)(const char *));
1866 
1867 extern unsigned int err_pos(char *cmd, const char *str);
1868 extern void tracing_log_err(struct trace_array *tr,
1869 			    const char *loc, const char *cmd,
1870 			    const char **errs, u8 type, u16 pos);
1871 
1872 /*
1873  * Normal trace_printk() and friends allocates special buffers
1874  * to do the manipulation, as well as saves the print formats
1875  * into sections to display. But the trace infrastructure wants
1876  * to use these without the added overhead at the price of being
1877  * a bit slower (used mainly for warnings, where we don't care
1878  * about performance). The internal_trace_puts() is for such
1879  * a purpose.
1880  */
1881 #define internal_trace_puts(str) __trace_puts(_THIS_IP_, str, strlen(str))
1882 
1883 #undef FTRACE_ENTRY
1884 #define FTRACE_ENTRY(call, struct_name, id, tstruct, print)	\
1885 	extern struct trace_event_call					\
1886 	__aligned(4) event_##call;
1887 #undef FTRACE_ENTRY_DUP
1888 #define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print)	\
1889 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
1890 #undef FTRACE_ENTRY_PACKED
1891 #define FTRACE_ENTRY_PACKED(call, struct_name, id, tstruct, print) \
1892 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
1893 
1894 #include "trace_entries.h"
1895 
1896 #if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_FUNCTION_TRACER)
1897 int perf_ftrace_event_register(struct trace_event_call *call,
1898 			       enum trace_reg type, void *data);
1899 #else
1900 #define perf_ftrace_event_register NULL
1901 #endif
1902 
1903 #ifdef CONFIG_FTRACE_SYSCALLS
1904 void init_ftrace_syscalls(void);
1905 const char *get_syscall_name(int syscall);
1906 #else
1907 static inline void init_ftrace_syscalls(void) { }
1908 static inline const char *get_syscall_name(int syscall)
1909 {
1910 	return NULL;
1911 }
1912 #endif
1913 
1914 #ifdef CONFIG_EVENT_TRACING
1915 void trace_event_init(void);
1916 void trace_event_eval_update(struct trace_eval_map **map, int len);
1917 /* Used from boot time tracer */
1918 extern int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set);
1919 extern int trigger_process_regex(struct trace_event_file *file, char *buff);
1920 #else
1921 static inline void __init trace_event_init(void) { }
1922 static inline void trace_event_eval_update(struct trace_eval_map **map, int len) { }
1923 #endif
1924 
1925 #ifdef CONFIG_TRACER_SNAPSHOT
1926 void tracing_snapshot_instance(struct trace_array *tr);
1927 int tracing_alloc_snapshot_instance(struct trace_array *tr);
1928 #else
1929 static inline void tracing_snapshot_instance(struct trace_array *tr) { }
1930 static inline int tracing_alloc_snapshot_instance(struct trace_array *tr)
1931 {
1932 	return 0;
1933 }
1934 #endif
1935 
1936 #ifdef CONFIG_PREEMPT_TRACER
1937 void tracer_preempt_on(unsigned long a0, unsigned long a1);
1938 void tracer_preempt_off(unsigned long a0, unsigned long a1);
1939 #else
1940 static inline void tracer_preempt_on(unsigned long a0, unsigned long a1) { }
1941 static inline void tracer_preempt_off(unsigned long a0, unsigned long a1) { }
1942 #endif
1943 #ifdef CONFIG_IRQSOFF_TRACER
1944 void tracer_hardirqs_on(unsigned long a0, unsigned long a1);
1945 void tracer_hardirqs_off(unsigned long a0, unsigned long a1);
1946 #else
1947 static inline void tracer_hardirqs_on(unsigned long a0, unsigned long a1) { }
1948 static inline void tracer_hardirqs_off(unsigned long a0, unsigned long a1) { }
1949 #endif
1950 
1951 /*
1952  * Reset the state of the trace_iterator so that it can read consumed data.
1953  * Normally, the trace_iterator is used for reading the data when it is not
1954  * consumed, and must retain state.
1955  */
1956 static __always_inline void trace_iterator_reset(struct trace_iterator *iter)
1957 {
1958 	memset_startat(iter, 0, seq);
1959 	iter->pos = -1;
1960 }
1961 
1962 /* Check the name is good for event/group/fields */
1963 static inline bool __is_good_name(const char *name, bool hash_ok)
1964 {
1965 	if (!isalpha(*name) && *name != '_' && (!hash_ok || *name != '-'))
1966 		return false;
1967 	while (*++name != '\0') {
1968 		if (!isalpha(*name) && !isdigit(*name) && *name != '_' &&
1969 		    (!hash_ok || *name != '-'))
1970 			return false;
1971 	}
1972 	return true;
1973 }
1974 
1975 /* Check the name is good for event/group/fields */
1976 static inline bool is_good_name(const char *name)
1977 {
1978 	return __is_good_name(name, false);
1979 }
1980 
1981 /* Check the name is good for system */
1982 static inline bool is_good_system_name(const char *name)
1983 {
1984 	return __is_good_name(name, true);
1985 }
1986 
1987 /* Convert certain expected symbols into '_' when generating event names */
1988 static inline void sanitize_event_name(char *name)
1989 {
1990 	while (*name++ != '\0')
1991 		if (*name == ':' || *name == '.')
1992 			*name = '_';
1993 }
1994 
1995 /*
1996  * This is a generic way to read and write a u64 value from a file in tracefs.
1997  *
1998  * The value is stored on the variable pointed by *val. The value needs
1999  * to be at least *min and at most *max. The write is protected by an
2000  * existing *lock.
2001  */
2002 struct trace_min_max_param {
2003 	struct mutex	*lock;
2004 	u64		*val;
2005 	u64		*min;
2006 	u64		*max;
2007 };
2008 
2009 #define U64_STR_SIZE		24	/* 20 digits max */
2010 
2011 extern const struct file_operations trace_min_max_fops;
2012 
2013 #ifdef CONFIG_RV
2014 extern int rv_init_interface(void);
2015 #else
2016 static inline int rv_init_interface(void)
2017 {
2018 	return 0;
2019 }
2020 #endif
2021 
2022 #endif /* _LINUX_KERNEL_TRACE_H */
2023