xref: /linux/kernel/trace/trace.h (revision fb6d03238e35f96cc1d6a5411ee1d684221d1c39)
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_GRAPH_RETADDR_ENT,
50 	TRACE_USER_STACK,
51 	TRACE_BLK,
52 	TRACE_BPUTS,
53 	TRACE_HWLAT,
54 	TRACE_OSNOISE,
55 	TRACE_TIMERLAT,
56 	TRACE_RAW_DATA,
57 	TRACE_FUNC_REPEATS,
58 
59 	__TRACE_LAST_TYPE,
60 };
61 
62 
63 #undef __field
64 #define __field(type, item)		type	item;
65 
66 #undef __field_fn
67 #define __field_fn(type, item)		type	item;
68 
69 #undef __field_struct
70 #define __field_struct(type, item)	__field(type, item)
71 
72 #undef __field_desc
73 #define __field_desc(type, container, item)
74 
75 #undef __field_packed
76 #define __field_packed(type, container, item)
77 
78 #undef __array
79 #define __array(type, item, size)	type	item[size];
80 
81 /*
82  * For backward compatibility, older user space expects to see the
83  * kernel_stack event with a fixed size caller field. But today the fix
84  * size is ignored by the kernel, and the real structure is dynamic.
85  * Expose to user space: "unsigned long caller[8];" but the real structure
86  * will be "unsigned long caller[] __counted_by(size)"
87  */
88 #undef __stack_array
89 #define __stack_array(type, item, size, field)		type item[] __counted_by(field);
90 
91 #undef __array_desc
92 #define __array_desc(type, container, item, size)
93 
94 #undef __dynamic_array
95 #define __dynamic_array(type, item)	type	item[];
96 
97 #undef __rel_dynamic_array
98 #define __rel_dynamic_array(type, item)	type	item[];
99 
100 #undef F_STRUCT
101 #define F_STRUCT(args...)		args
102 
103 #undef FTRACE_ENTRY
104 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print)		\
105 	struct struct_name {						\
106 		struct trace_entry	ent;				\
107 		tstruct							\
108 	}
109 
110 #undef FTRACE_ENTRY_DUP
111 #define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk)
112 
113 #undef FTRACE_ENTRY_REG
114 #define FTRACE_ENTRY_REG(name, struct_name, id, tstruct, print,	regfn)	\
115 	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print))
116 
117 #undef FTRACE_ENTRY_PACKED
118 #define FTRACE_ENTRY_PACKED(name, struct_name, id, tstruct, print)	\
119 	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print)) __packed
120 
121 #include "trace_entries.h"
122 
123 /* Use this for memory failure errors */
124 #define MEM_FAIL(condition, fmt, ...)					\
125 	DO_ONCE_LITE_IF(condition, pr_err, "ERROR: " fmt, ##__VA_ARGS__)
126 
127 #define FAULT_STRING "(fault)"
128 
129 #define HIST_STACKTRACE_DEPTH	16
130 #define HIST_STACKTRACE_SIZE	(HIST_STACKTRACE_DEPTH * sizeof(unsigned long))
131 #define HIST_STACKTRACE_SKIP	5
132 
133 /*
134  * syscalls are special, and need special handling, this is why
135  * they are not included in trace_entries.h
136  */
137 struct syscall_trace_enter {
138 	struct trace_entry	ent;
139 	int			nr;
140 	unsigned long		args[];
141 };
142 
143 struct syscall_trace_exit {
144 	struct trace_entry	ent;
145 	int			nr;
146 	long			ret;
147 };
148 
149 struct kprobe_trace_entry_head {
150 	struct trace_entry	ent;
151 	unsigned long		ip;
152 };
153 
154 struct eprobe_trace_entry_head {
155 	struct trace_entry	ent;
156 };
157 
158 struct kretprobe_trace_entry_head {
159 	struct trace_entry	ent;
160 	unsigned long		func;
161 	unsigned long		ret_ip;
162 };
163 
164 struct fentry_trace_entry_head {
165 	struct trace_entry	ent;
166 	unsigned long		ip;
167 };
168 
169 struct fexit_trace_entry_head {
170 	struct trace_entry	ent;
171 	unsigned long		func;
172 	unsigned long		ret_ip;
173 };
174 
175 #define TRACE_BUF_SIZE		1024
176 
177 struct trace_array;
178 
179 /*
180  * The CPU trace array - it consists of thousands of trace entries
181  * plus some other descriptor data: (for example which task started
182  * the trace, etc.)
183  */
184 struct trace_array_cpu {
185 	atomic_t		disabled;
186 	void			*buffer_page;	/* ring buffer spare */
187 
188 	unsigned long		entries;
189 	unsigned long		saved_latency;
190 	unsigned long		critical_start;
191 	unsigned long		critical_end;
192 	unsigned long		critical_sequence;
193 	unsigned long		nice;
194 	unsigned long		policy;
195 	unsigned long		rt_priority;
196 	unsigned long		skipped_entries;
197 	u64			preempt_timestamp;
198 	pid_t			pid;
199 	kuid_t			uid;
200 	char			comm[TASK_COMM_LEN];
201 
202 #ifdef CONFIG_FUNCTION_TRACER
203 	int			ftrace_ignore_pid;
204 #endif
205 	bool			ignore_pid;
206 };
207 
208 struct tracer;
209 struct trace_option_dentry;
210 
211 struct array_buffer {
212 	struct trace_array		*tr;
213 	struct trace_buffer		*buffer;
214 	struct trace_array_cpu __percpu	*data;
215 	u64				time_start;
216 	int				cpu;
217 };
218 
219 #define TRACE_FLAGS_MAX_SIZE		32
220 
221 struct trace_options {
222 	struct tracer			*tracer;
223 	struct trace_option_dentry	*topts;
224 };
225 
226 struct trace_pid_list *trace_pid_list_alloc(void);
227 void trace_pid_list_free(struct trace_pid_list *pid_list);
228 bool trace_pid_list_is_set(struct trace_pid_list *pid_list, unsigned int pid);
229 int trace_pid_list_set(struct trace_pid_list *pid_list, unsigned int pid);
230 int trace_pid_list_clear(struct trace_pid_list *pid_list, unsigned int pid);
231 int trace_pid_list_first(struct trace_pid_list *pid_list, unsigned int *pid);
232 int trace_pid_list_next(struct trace_pid_list *pid_list, unsigned int pid,
233 			unsigned int *next);
234 
235 enum {
236 	TRACE_PIDS		= BIT(0),
237 	TRACE_NO_PIDS		= BIT(1),
238 };
239 
240 static inline bool pid_type_enabled(int type, struct trace_pid_list *pid_list,
241 				    struct trace_pid_list *no_pid_list)
242 {
243 	/* Return true if the pid list in type has pids */
244 	return ((type & TRACE_PIDS) && pid_list) ||
245 		((type & TRACE_NO_PIDS) && no_pid_list);
246 }
247 
248 static inline bool still_need_pid_events(int type, struct trace_pid_list *pid_list,
249 					 struct trace_pid_list *no_pid_list)
250 {
251 	/*
252 	 * Turning off what is in @type, return true if the "other"
253 	 * pid list, still has pids in it.
254 	 */
255 	return (!(type & TRACE_PIDS) && pid_list) ||
256 		(!(type & TRACE_NO_PIDS) && no_pid_list);
257 }
258 
259 typedef bool (*cond_update_fn_t)(struct trace_array *tr, void *cond_data);
260 
261 /**
262  * struct cond_snapshot - conditional snapshot data and callback
263  *
264  * The cond_snapshot structure encapsulates a callback function and
265  * data associated with the snapshot for a given tracing instance.
266  *
267  * When a snapshot is taken conditionally, by invoking
268  * tracing_snapshot_cond(tr, cond_data), the cond_data passed in is
269  * passed in turn to the cond_snapshot.update() function.  That data
270  * can be compared by the update() implementation with the cond_data
271  * contained within the struct cond_snapshot instance associated with
272  * the trace_array.  Because the tr->max_lock is held throughout the
273  * update() call, the update() function can directly retrieve the
274  * cond_snapshot and cond_data associated with the per-instance
275  * snapshot associated with the trace_array.
276  *
277  * The cond_snapshot.update() implementation can save data to be
278  * associated with the snapshot if it decides to, and returns 'true'
279  * in that case, or it returns 'false' if the conditional snapshot
280  * shouldn't be taken.
281  *
282  * The cond_snapshot instance is created and associated with the
283  * user-defined cond_data by tracing_cond_snapshot_enable().
284  * Likewise, the cond_snapshot instance is destroyed and is no longer
285  * associated with the trace instance by
286  * tracing_cond_snapshot_disable().
287  *
288  * The method below is required.
289  *
290  * @update: When a conditional snapshot is invoked, the update()
291  *	callback function is invoked with the tr->max_lock held.  The
292  *	update() implementation signals whether or not to actually
293  *	take the snapshot, by returning 'true' if so, 'false' if no
294  *	snapshot should be taken.  Because the max_lock is held for
295  *	the duration of update(), the implementation is safe to
296  *	directly retrieved and save any implementation data it needs
297  *	to in association with the snapshot.
298  */
299 struct cond_snapshot {
300 	void				*cond_data;
301 	cond_update_fn_t		update;
302 };
303 
304 /*
305  * struct trace_func_repeats - used to keep track of the consecutive
306  * (on the same CPU) calls of a single function.
307  */
308 struct trace_func_repeats {
309 	unsigned long	ip;
310 	unsigned long	parent_ip;
311 	unsigned long	count;
312 	u64		ts_last_call;
313 };
314 
315 /*
316  * The trace array - an array of per-CPU trace arrays. This is the
317  * highest level data structure that individual tracers deal with.
318  * They have on/off state as well:
319  */
320 struct trace_array {
321 	struct list_head	list;
322 	char			*name;
323 	struct array_buffer	array_buffer;
324 #ifdef CONFIG_TRACER_MAX_TRACE
325 	/*
326 	 * The max_buffer is used to snapshot the trace when a maximum
327 	 * latency is reached, or when the user initiates a snapshot.
328 	 * Some tracers will use this to store a maximum trace while
329 	 * it continues examining live traces.
330 	 *
331 	 * The buffers for the max_buffer are set up the same as the array_buffer
332 	 * When a snapshot is taken, the buffer of the max_buffer is swapped
333 	 * with the buffer of the array_buffer and the buffers are reset for
334 	 * the array_buffer so the tracing can continue.
335 	 */
336 	struct array_buffer	max_buffer;
337 	bool			allocated_snapshot;
338 	spinlock_t		snapshot_trigger_lock;
339 	unsigned int		snapshot;
340 	unsigned long		max_latency;
341 #ifdef CONFIG_FSNOTIFY
342 	struct dentry		*d_max_latency;
343 	struct work_struct	fsnotify_work;
344 	struct irq_work		fsnotify_irqwork;
345 #endif
346 #endif
347 	/* The below is for memory mapped ring buffer */
348 	unsigned int		mapped;
349 	unsigned long		range_addr_start;
350 	unsigned long		range_addr_size;
351 	char			*range_name;
352 	long			text_delta;
353 	void			*scratch; /* pointer in persistent memory */
354 	int			scratch_size;
355 
356 	int			buffer_disabled;
357 
358 	struct trace_pid_list	__rcu *filtered_pids;
359 	struct trace_pid_list	__rcu *filtered_no_pids;
360 	/*
361 	 * max_lock is used to protect the swapping of buffers
362 	 * when taking a max snapshot. The buffers themselves are
363 	 * protected by per_cpu spinlocks. But the action of the swap
364 	 * needs its own lock.
365 	 *
366 	 * This is defined as a arch_spinlock_t in order to help
367 	 * with performance when lockdep debugging is enabled.
368 	 *
369 	 * It is also used in other places outside the update_max_tr
370 	 * so it needs to be defined outside of the
371 	 * CONFIG_TRACER_MAX_TRACE.
372 	 */
373 	arch_spinlock_t		max_lock;
374 #ifdef CONFIG_FTRACE_SYSCALLS
375 	int			sys_refcount_enter;
376 	int			sys_refcount_exit;
377 	struct trace_event_file __rcu *enter_syscall_files[NR_syscalls];
378 	struct trace_event_file __rcu *exit_syscall_files[NR_syscalls];
379 #endif
380 	int			stop_count;
381 	int			clock_id;
382 	int			nr_topts;
383 	bool			clear_trace;
384 	int			buffer_percent;
385 	unsigned int		n_err_log_entries;
386 	struct tracer		*current_trace;
387 	unsigned int		trace_flags;
388 	unsigned char		trace_flags_index[TRACE_FLAGS_MAX_SIZE];
389 	unsigned int		flags;
390 	raw_spinlock_t		start_lock;
391 	const char		*system_names;
392 	struct list_head	err_log;
393 	struct dentry		*dir;
394 	struct dentry		*options;
395 	struct dentry		*percpu_dir;
396 	struct eventfs_inode	*event_dir;
397 	struct trace_options	*topts;
398 	struct list_head	systems;
399 	struct list_head	events;
400 	struct trace_event_file *trace_marker_file;
401 	cpumask_var_t		tracing_cpumask; /* only trace on set CPUs */
402 	/* one per_cpu trace_pipe can be opened by only one user */
403 	cpumask_var_t		pipe_cpumask;
404 	int			ref;
405 	int			trace_ref;
406 #ifdef CONFIG_MODULES
407 	struct list_head	mod_events;
408 #endif
409 #ifdef CONFIG_FUNCTION_TRACER
410 	struct ftrace_ops	*ops;
411 	struct trace_pid_list	__rcu *function_pids;
412 	struct trace_pid_list	__rcu *function_no_pids;
413 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
414 	struct fgraph_ops	*gops;
415 #endif
416 #ifdef CONFIG_DYNAMIC_FTRACE
417 	/* All of these are protected by the ftrace_lock */
418 	struct list_head	func_probes;
419 	struct list_head	mod_trace;
420 	struct list_head	mod_notrace;
421 #endif
422 	/* function tracing enabled */
423 	int			function_enabled;
424 #endif
425 	int			no_filter_buffering_ref;
426 	struct list_head	hist_vars;
427 #ifdef CONFIG_TRACER_SNAPSHOT
428 	struct cond_snapshot	*cond_snapshot;
429 #endif
430 	struct trace_func_repeats	__percpu *last_func_repeats;
431 	/*
432 	 * On boot up, the ring buffer is set to the minimum size, so that
433 	 * we do not waste memory on systems that are not using tracing.
434 	 */
435 	bool ring_buffer_expanded;
436 };
437 
438 enum {
439 	TRACE_ARRAY_FL_GLOBAL		= BIT(0),
440 	TRACE_ARRAY_FL_BOOT		= BIT(1),
441 	TRACE_ARRAY_FL_LAST_BOOT	= BIT(2),
442 	TRACE_ARRAY_FL_MOD_INIT		= BIT(3),
443 };
444 
445 #ifdef CONFIG_MODULES
446 bool module_exists(const char *module);
447 #else
448 static inline bool module_exists(const char *module)
449 {
450 	return false;
451 }
452 #endif
453 
454 extern struct list_head ftrace_trace_arrays;
455 
456 extern struct mutex trace_types_lock;
457 
458 extern int trace_array_get(struct trace_array *tr);
459 extern int tracing_check_open_get_tr(struct trace_array *tr);
460 extern struct trace_array *trace_array_find(const char *instance);
461 extern struct trace_array *trace_array_find_get(const char *instance);
462 
463 extern u64 tracing_event_time_stamp(struct trace_buffer *buffer, struct ring_buffer_event *rbe);
464 extern int tracing_set_filter_buffering(struct trace_array *tr, bool set);
465 extern int tracing_set_clock(struct trace_array *tr, const char *clockstr);
466 
467 extern bool trace_clock_in_ns(struct trace_array *tr);
468 
469 /*
470  * The global tracer (top) should be the first trace array added,
471  * but we check the flag anyway.
472  */
473 static inline struct trace_array *top_trace_array(void)
474 {
475 	struct trace_array *tr;
476 
477 	if (list_empty(&ftrace_trace_arrays))
478 		return NULL;
479 
480 	tr = list_entry(ftrace_trace_arrays.prev,
481 			typeof(*tr), list);
482 	WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
483 	return tr;
484 }
485 
486 #define FTRACE_CMP_TYPE(var, type) \
487 	__builtin_types_compatible_p(typeof(var), type *)
488 
489 #undef IF_ASSIGN
490 #define IF_ASSIGN(var, entry, etype, id)			\
491 	if (FTRACE_CMP_TYPE(var, etype)) {			\
492 		var = (typeof(var))(entry);			\
493 		WARN_ON(id != 0 && (entry)->type != id);	\
494 		break;						\
495 	}
496 
497 /* Will cause compile errors if type is not found. */
498 extern void __ftrace_bad_type(void);
499 
500 /*
501  * The trace_assign_type is a verifier that the entry type is
502  * the same as the type being assigned. To add new types simply
503  * add a line with the following format:
504  *
505  * IF_ASSIGN(var, ent, type, id);
506  *
507  *  Where "type" is the trace type that includes the trace_entry
508  *  as the "ent" item. And "id" is the trace identifier that is
509  *  used in the trace_type enum.
510  *
511  *  If the type can have more than one id, then use zero.
512  */
513 #define trace_assign_type(var, ent)					\
514 	do {								\
515 		IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);	\
516 		IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);	\
517 		IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);	\
518 		IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
519 		IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);	\
520 		IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT);	\
521 		IF_ASSIGN(var, ent, struct bputs_entry, TRACE_BPUTS);	\
522 		IF_ASSIGN(var, ent, struct hwlat_entry, TRACE_HWLAT);	\
523 		IF_ASSIGN(var, ent, struct osnoise_entry, TRACE_OSNOISE);\
524 		IF_ASSIGN(var, ent, struct timerlat_entry, TRACE_TIMERLAT);\
525 		IF_ASSIGN(var, ent, struct raw_data_entry, TRACE_RAW_DATA);\
526 		IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,		\
527 			  TRACE_MMIO_RW);				\
528 		IF_ASSIGN(var, ent, struct trace_mmiotrace_map,		\
529 			  TRACE_MMIO_MAP);				\
530 		IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
531 		IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,	\
532 			  TRACE_GRAPH_ENT);		\
533 		IF_ASSIGN(var, ent, struct fgraph_retaddr_ent_entry,\
534 			  TRACE_GRAPH_RETADDR_ENT);		\
535 		IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,	\
536 			  TRACE_GRAPH_RET);		\
537 		IF_ASSIGN(var, ent, struct func_repeats_entry,		\
538 			  TRACE_FUNC_REPEATS);				\
539 		__ftrace_bad_type();					\
540 	} while (0)
541 
542 /*
543  * An option specific to a tracer. This is a boolean value.
544  * The bit is the bit index that sets its value on the
545  * flags value in struct tracer_flags.
546  */
547 struct tracer_opt {
548 	const char	*name; /* Will appear on the trace_options file */
549 	u32		bit; /* Mask assigned in val field in tracer_flags */
550 };
551 
552 /*
553  * The set of specific options for a tracer. Your tracer
554  * have to set the initial value of the flags val.
555  */
556 struct tracer_flags {
557 	u32			val;
558 	struct tracer_opt	*opts;
559 	struct tracer		*trace;
560 };
561 
562 /* Makes more easy to define a tracer opt */
563 #define TRACER_OPT(s, b)	.name = #s, .bit = b
564 
565 
566 struct trace_option_dentry {
567 	struct tracer_opt		*opt;
568 	struct tracer_flags		*flags;
569 	struct trace_array		*tr;
570 	struct dentry			*entry;
571 };
572 
573 /**
574  * struct tracer - a specific tracer and its callbacks to interact with tracefs
575  * @name: the name chosen to select it on the available_tracers file
576  * @init: called when one switches to this tracer (echo name > current_tracer)
577  * @reset: called when one switches to another tracer
578  * @start: called when tracing is unpaused (echo 1 > tracing_on)
579  * @stop: called when tracing is paused (echo 0 > tracing_on)
580  * @update_thresh: called when tracing_thresh is updated
581  * @open: called when the trace file is opened
582  * @pipe_open: called when the trace_pipe file is opened
583  * @close: called when the trace file is released
584  * @pipe_close: called when the trace_pipe file is released
585  * @read: override the default read callback on trace_pipe
586  * @splice_read: override the default splice_read callback on trace_pipe
587  * @selftest: selftest to run on boot (see trace_selftest.c)
588  * @print_headers: override the first lines that describe your columns
589  * @print_line: callback that prints a trace
590  * @set_flag: signals one of your private flags changed (trace_options file)
591  * @flags: your private flags
592  */
593 struct tracer {
594 	const char		*name;
595 	int			(*init)(struct trace_array *tr);
596 	void			(*reset)(struct trace_array *tr);
597 	void			(*start)(struct trace_array *tr);
598 	void			(*stop)(struct trace_array *tr);
599 	int			(*update_thresh)(struct trace_array *tr);
600 	void			(*open)(struct trace_iterator *iter);
601 	void			(*pipe_open)(struct trace_iterator *iter);
602 	void			(*close)(struct trace_iterator *iter);
603 	void			(*pipe_close)(struct trace_iterator *iter);
604 	ssize_t			(*read)(struct trace_iterator *iter,
605 					struct file *filp, char __user *ubuf,
606 					size_t cnt, loff_t *ppos);
607 	ssize_t			(*splice_read)(struct trace_iterator *iter,
608 					       struct file *filp,
609 					       loff_t *ppos,
610 					       struct pipe_inode_info *pipe,
611 					       size_t len,
612 					       unsigned int flags);
613 #ifdef CONFIG_FTRACE_STARTUP_TEST
614 	int			(*selftest)(struct tracer *trace,
615 					    struct trace_array *tr);
616 #endif
617 	void			(*print_header)(struct seq_file *m);
618 	enum print_line_t	(*print_line)(struct trace_iterator *iter);
619 	/* If you handled the flag setting, return 0 */
620 	int			(*set_flag)(struct trace_array *tr,
621 					    u32 old_flags, u32 bit, int set);
622 	/* Return 0 if OK with change, else return non-zero */
623 	int			(*flag_changed)(struct trace_array *tr,
624 						u32 mask, int set);
625 	struct tracer		*next;
626 	struct tracer_flags	*flags;
627 	int			enabled;
628 	bool			print_max;
629 	bool			allow_instances;
630 #ifdef CONFIG_TRACER_MAX_TRACE
631 	bool			use_max_tr;
632 #endif
633 	/* True if tracer cannot be enabled in kernel param */
634 	bool			noboot;
635 };
636 
637 static inline struct ring_buffer_iter *
638 trace_buffer_iter(struct trace_iterator *iter, int cpu)
639 {
640 	return iter->buffer_iter ? iter->buffer_iter[cpu] : NULL;
641 }
642 
643 int tracer_init(struct tracer *t, struct trace_array *tr);
644 int tracing_is_enabled(void);
645 void tracing_reset_online_cpus(struct array_buffer *buf);
646 void tracing_reset_all_online_cpus(void);
647 void tracing_reset_all_online_cpus_unlocked(void);
648 int tracing_open_generic(struct inode *inode, struct file *filp);
649 int tracing_open_generic_tr(struct inode *inode, struct file *filp);
650 int tracing_release_generic_tr(struct inode *inode, struct file *file);
651 int tracing_open_file_tr(struct inode *inode, struct file *filp);
652 int tracing_release_file_tr(struct inode *inode, struct file *filp);
653 int tracing_single_release_file_tr(struct inode *inode, struct file *filp);
654 bool tracing_is_disabled(void);
655 bool tracer_tracing_is_on(struct trace_array *tr);
656 void tracer_tracing_on(struct trace_array *tr);
657 void tracer_tracing_off(struct trace_array *tr);
658 struct dentry *trace_create_file(const char *name,
659 				 umode_t mode,
660 				 struct dentry *parent,
661 				 void *data,
662 				 const struct file_operations *fops);
663 
664 int tracing_init_dentry(void);
665 
666 struct ring_buffer_event;
667 
668 struct ring_buffer_event *
669 trace_buffer_lock_reserve(struct trace_buffer *buffer,
670 			  int type,
671 			  unsigned long len,
672 			  unsigned int trace_ctx);
673 
674 int ring_buffer_meta_seq_init(struct file *file, struct trace_buffer *buffer, int cpu);
675 
676 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
677 						struct trace_array_cpu *data);
678 
679 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
680 					  int *ent_cpu, u64 *ent_ts);
681 
682 void trace_buffer_unlock_commit_nostack(struct trace_buffer *buffer,
683 					struct ring_buffer_event *event);
684 
685 bool trace_is_tracepoint_string(const char *str);
686 const char *trace_event_format(struct trace_iterator *iter, const char *fmt);
687 char *trace_iter_expand_format(struct trace_iterator *iter);
688 bool ignore_event(struct trace_iterator *iter);
689 
690 int trace_empty(struct trace_iterator *iter);
691 
692 void *trace_find_next_entry_inc(struct trace_iterator *iter);
693 
694 void trace_init_global_iter(struct trace_iterator *iter);
695 
696 void tracing_iter_reset(struct trace_iterator *iter, int cpu);
697 
698 unsigned long trace_total_entries_cpu(struct trace_array *tr, int cpu);
699 unsigned long trace_total_entries(struct trace_array *tr);
700 
701 void trace_function(struct trace_array *tr,
702 		    unsigned long ip,
703 		    unsigned long parent_ip,
704 		    unsigned int trace_ctx);
705 void trace_graph_function(struct trace_array *tr,
706 		    unsigned long ip,
707 		    unsigned long parent_ip,
708 		    unsigned int trace_ctx);
709 void trace_latency_header(struct seq_file *m);
710 void trace_default_header(struct seq_file *m);
711 void print_trace_header(struct seq_file *m, struct trace_iterator *iter);
712 
713 void trace_graph_return(struct ftrace_graph_ret *trace, struct fgraph_ops *gops,
714 			struct ftrace_regs *fregs);
715 int trace_graph_entry(struct ftrace_graph_ent *trace, struct fgraph_ops *gops,
716 		      struct ftrace_regs *fregs);
717 
718 void tracing_start_cmdline_record(void);
719 void tracing_stop_cmdline_record(void);
720 void tracing_start_tgid_record(void);
721 void tracing_stop_tgid_record(void);
722 
723 int register_tracer(struct tracer *type);
724 int is_tracing_stopped(void);
725 
726 loff_t tracing_lseek(struct file *file, loff_t offset, int whence);
727 
728 extern cpumask_var_t __read_mostly tracing_buffer_mask;
729 
730 #define for_each_tracing_cpu(cpu)	\
731 	for_each_cpu(cpu, tracing_buffer_mask)
732 
733 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
734 
735 extern unsigned long tracing_thresh;
736 
737 /* PID filtering */
738 
739 bool trace_find_filtered_pid(struct trace_pid_list *filtered_pids,
740 			     pid_t search_pid);
741 bool trace_ignore_this_task(struct trace_pid_list *filtered_pids,
742 			    struct trace_pid_list *filtered_no_pids,
743 			    struct task_struct *task);
744 void trace_filter_add_remove_task(struct trace_pid_list *pid_list,
745 				  struct task_struct *self,
746 				  struct task_struct *task);
747 void *trace_pid_next(struct trace_pid_list *pid_list, void *v, loff_t *pos);
748 void *trace_pid_start(struct trace_pid_list *pid_list, loff_t *pos);
749 int trace_pid_show(struct seq_file *m, void *v);
750 int trace_pid_write(struct trace_pid_list *filtered_pids,
751 		    struct trace_pid_list **new_pid_list,
752 		    const char __user *ubuf, size_t cnt);
753 
754 #ifdef CONFIG_TRACER_MAX_TRACE
755 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu,
756 		   void *cond_data);
757 void update_max_tr_single(struct trace_array *tr,
758 			  struct task_struct *tsk, int cpu);
759 
760 #ifdef CONFIG_FSNOTIFY
761 #define LATENCY_FS_NOTIFY
762 #endif
763 #endif /* CONFIG_TRACER_MAX_TRACE */
764 
765 #ifdef LATENCY_FS_NOTIFY
766 void latency_fsnotify(struct trace_array *tr);
767 #else
768 static inline void latency_fsnotify(struct trace_array *tr) { }
769 #endif
770 
771 #ifdef CONFIG_STACKTRACE
772 void __trace_stack(struct trace_array *tr, unsigned int trace_ctx, int skip);
773 #else
774 static inline void __trace_stack(struct trace_array *tr, unsigned int trace_ctx,
775 				 int skip)
776 {
777 }
778 #endif /* CONFIG_STACKTRACE */
779 
780 void trace_last_func_repeats(struct trace_array *tr,
781 			     struct trace_func_repeats *last_info,
782 			     unsigned int trace_ctx);
783 
784 extern u64 ftrace_now(int cpu);
785 
786 extern void trace_find_cmdline(int pid, char comm[]);
787 extern int trace_find_tgid(int pid);
788 extern void trace_event_follow_fork(struct trace_array *tr, bool enable);
789 
790 extern int trace_events_enabled(struct trace_array *tr, const char *system);
791 
792 #ifdef CONFIG_DYNAMIC_FTRACE
793 extern unsigned long ftrace_update_tot_cnt;
794 extern unsigned long ftrace_number_of_pages;
795 extern unsigned long ftrace_number_of_groups;
796 extern u64 ftrace_update_time;
797 extern u64 ftrace_total_mod_time;
798 void ftrace_init_trace_array(struct trace_array *tr);
799 #else
800 static inline void ftrace_init_trace_array(struct trace_array *tr) { }
801 #endif
802 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
803 extern int DYN_FTRACE_TEST_NAME(void);
804 #define DYN_FTRACE_TEST_NAME2 trace_selftest_dynamic_test_func2
805 extern int DYN_FTRACE_TEST_NAME2(void);
806 
807 extern void trace_set_ring_buffer_expanded(struct trace_array *tr);
808 extern bool tracing_selftest_disabled;
809 
810 #ifdef CONFIG_FTRACE_STARTUP_TEST
811 extern void __init disable_tracing_selftest(const char *reason);
812 
813 extern int trace_selftest_startup_function(struct tracer *trace,
814 					   struct trace_array *tr);
815 extern int trace_selftest_startup_function_graph(struct tracer *trace,
816 						 struct trace_array *tr);
817 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
818 					  struct trace_array *tr);
819 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
820 					     struct trace_array *tr);
821 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
822 						 struct trace_array *tr);
823 extern int trace_selftest_startup_wakeup(struct tracer *trace,
824 					 struct trace_array *tr);
825 extern int trace_selftest_startup_nop(struct tracer *trace,
826 					 struct trace_array *tr);
827 extern int trace_selftest_startup_branch(struct tracer *trace,
828 					 struct trace_array *tr);
829 /*
830  * Tracer data references selftest functions that only occur
831  * on boot up. These can be __init functions. Thus, when selftests
832  * are enabled, then the tracers need to reference __init functions.
833  */
834 #define __tracer_data		__refdata
835 #else
836 static inline void __init disable_tracing_selftest(const char *reason)
837 {
838 }
839 /* Tracers are seldom changed. Optimize when selftests are disabled. */
840 #define __tracer_data		__read_mostly
841 #endif /* CONFIG_FTRACE_STARTUP_TEST */
842 
843 extern void *head_page(struct trace_array_cpu *data);
844 extern unsigned long long ns2usecs(u64 nsec);
845 extern int
846 trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
847 extern int
848 trace_vprintk(unsigned long ip, const char *fmt, va_list args);
849 extern int
850 trace_array_vprintk(struct trace_array *tr,
851 		    unsigned long ip, const char *fmt, va_list args);
852 int trace_array_printk_buf(struct trace_buffer *buffer,
853 			   unsigned long ip, const char *fmt, ...);
854 void trace_printk_seq(struct trace_seq *s);
855 enum print_line_t print_trace_line(struct trace_iterator *iter);
856 
857 extern char trace_find_mark(unsigned long long duration);
858 
859 struct ftrace_hash;
860 
861 struct ftrace_mod_load {
862 	struct list_head	list;
863 	char			*func;
864 	char			*module;
865 	int			 enable;
866 };
867 
868 enum {
869 	FTRACE_HASH_FL_MOD	= (1 << 0),
870 };
871 
872 struct ftrace_hash {
873 	unsigned long		size_bits;
874 	struct hlist_head	*buckets;
875 	unsigned long		count;
876 	unsigned long		flags;
877 	struct rcu_head		rcu;
878 };
879 
880 struct ftrace_func_entry *
881 ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip);
882 
883 static __always_inline bool ftrace_hash_empty(struct ftrace_hash *hash)
884 {
885 	return !hash || !(hash->count || (hash->flags & FTRACE_HASH_FL_MOD));
886 }
887 
888 /* Standard output formatting function used for function return traces */
889 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
890 
891 /* Flag options */
892 #define TRACE_GRAPH_PRINT_OVERRUN       0x1
893 #define TRACE_GRAPH_PRINT_CPU           0x2
894 #define TRACE_GRAPH_PRINT_OVERHEAD      0x4
895 #define TRACE_GRAPH_PRINT_PROC          0x8
896 #define TRACE_GRAPH_PRINT_DURATION      0x10
897 #define TRACE_GRAPH_PRINT_ABS_TIME      0x20
898 #define TRACE_GRAPH_PRINT_REL_TIME      0x40
899 #define TRACE_GRAPH_PRINT_IRQS          0x80
900 #define TRACE_GRAPH_PRINT_TAIL          0x100
901 #define TRACE_GRAPH_SLEEP_TIME          0x200
902 #define TRACE_GRAPH_GRAPH_TIME          0x400
903 #define TRACE_GRAPH_PRINT_RETVAL        0x800
904 #define TRACE_GRAPH_PRINT_RETVAL_HEX    0x1000
905 #define TRACE_GRAPH_PRINT_RETADDR       0x2000
906 #define TRACE_GRAPH_PRINT_FILL_SHIFT	28
907 #define TRACE_GRAPH_PRINT_FILL_MASK	(0x3 << TRACE_GRAPH_PRINT_FILL_SHIFT)
908 
909 extern void ftrace_graph_sleep_time_control(bool enable);
910 
911 #ifdef CONFIG_FUNCTION_PROFILER
912 extern void ftrace_graph_graph_time_control(bool enable);
913 #else
914 static inline void ftrace_graph_graph_time_control(bool enable) { }
915 #endif
916 
917 extern enum print_line_t
918 print_graph_function_flags(struct trace_iterator *iter, u32 flags);
919 extern void print_graph_headers_flags(struct seq_file *s, u32 flags);
920 extern void
921 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
922 extern void graph_trace_open(struct trace_iterator *iter);
923 extern void graph_trace_close(struct trace_iterator *iter);
924 extern int __trace_graph_entry(struct trace_array *tr,
925 			       struct ftrace_graph_ent *trace,
926 			       unsigned int trace_ctx);
927 extern int __trace_graph_retaddr_entry(struct trace_array *tr,
928 				struct ftrace_graph_ent *trace,
929 				unsigned int trace_ctx,
930 				unsigned long retaddr);
931 extern void __trace_graph_return(struct trace_array *tr,
932 				 struct ftrace_graph_ret *trace,
933 				 unsigned int trace_ctx,
934 				 u64 calltime, u64 rettime);
935 
936 extern void init_array_fgraph_ops(struct trace_array *tr, struct ftrace_ops *ops);
937 extern int allocate_fgraph_ops(struct trace_array *tr, struct ftrace_ops *ops);
938 extern void free_fgraph_ops(struct trace_array *tr);
939 
940 enum {
941 	TRACE_GRAPH_FL		= 1,
942 
943 	/*
944 	 * In the very unlikely case that an interrupt came in
945 	 * at a start of graph tracing, and we want to trace
946 	 * the function in that interrupt, the depth can be greater
947 	 * than zero, because of the preempted start of a previous
948 	 * trace. In an even more unlikely case, depth could be 2
949 	 * if a softirq interrupted the start of graph tracing,
950 	 * followed by an interrupt preempting a start of graph
951 	 * tracing in the softirq, and depth can even be 3
952 	 * if an NMI came in at the start of an interrupt function
953 	 * that preempted a softirq start of a function that
954 	 * preempted normal context!!!! Luckily, it can't be
955 	 * greater than 3, so the next two bits are a mask
956 	 * of what the depth is when we set TRACE_GRAPH_FL
957 	 */
958 
959 	TRACE_GRAPH_DEPTH_START_BIT,
960 	TRACE_GRAPH_DEPTH_END_BIT,
961 
962 	/*
963 	 * To implement set_graph_notrace, if this bit is set, we ignore
964 	 * function graph tracing of called functions, until the return
965 	 * function is called to clear it.
966 	 */
967 	TRACE_GRAPH_NOTRACE_BIT,
968 };
969 
970 #define TRACE_GRAPH_NOTRACE		(1 << TRACE_GRAPH_NOTRACE_BIT)
971 
972 static inline unsigned long ftrace_graph_depth(unsigned long *task_var)
973 {
974 	return (*task_var >> TRACE_GRAPH_DEPTH_START_BIT) & 3;
975 }
976 
977 static inline void ftrace_graph_set_depth(unsigned long *task_var, int depth)
978 {
979 	*task_var &= ~(3 << TRACE_GRAPH_DEPTH_START_BIT);
980 	*task_var |= (depth & 3) << TRACE_GRAPH_DEPTH_START_BIT;
981 }
982 
983 #ifdef CONFIG_DYNAMIC_FTRACE
984 extern struct ftrace_hash __rcu *ftrace_graph_hash;
985 extern struct ftrace_hash __rcu *ftrace_graph_notrace_hash;
986 
987 static inline int
988 ftrace_graph_addr(unsigned long *task_var, struct ftrace_graph_ent *trace)
989 {
990 	unsigned long addr = trace->func;
991 	int ret = 0;
992 	struct ftrace_hash *hash;
993 
994 	preempt_disable_notrace();
995 
996 	/*
997 	 * Have to open code "rcu_dereference_sched()" because the
998 	 * function graph tracer can be called when RCU is not
999 	 * "watching".
1000 	 * Protected with schedule_on_each_cpu(ftrace_sync)
1001 	 */
1002 	hash = rcu_dereference_protected(ftrace_graph_hash, !preemptible());
1003 
1004 	if (ftrace_hash_empty(hash)) {
1005 		ret = 1;
1006 		goto out;
1007 	}
1008 
1009 	if (ftrace_lookup_ip(hash, addr)) {
1010 		/*
1011 		 * This needs to be cleared on the return functions
1012 		 * when the depth is zero.
1013 		 */
1014 		*task_var |= TRACE_GRAPH_FL;
1015 		ftrace_graph_set_depth(task_var, trace->depth);
1016 
1017 		/*
1018 		 * If no irqs are to be traced, but a set_graph_function
1019 		 * is set, and called by an interrupt handler, we still
1020 		 * want to trace it.
1021 		 */
1022 		if (in_hardirq())
1023 			trace_recursion_set(TRACE_IRQ_BIT);
1024 		else
1025 			trace_recursion_clear(TRACE_IRQ_BIT);
1026 		ret = 1;
1027 	}
1028 
1029 out:
1030 	preempt_enable_notrace();
1031 	return ret;
1032 }
1033 
1034 static inline void
1035 ftrace_graph_addr_finish(struct fgraph_ops *gops, struct ftrace_graph_ret *trace)
1036 {
1037 	unsigned long *task_var = fgraph_get_task_var(gops);
1038 
1039 	if ((*task_var & TRACE_GRAPH_FL) &&
1040 	    trace->depth == ftrace_graph_depth(task_var))
1041 		*task_var &= ~TRACE_GRAPH_FL;
1042 }
1043 
1044 static inline int ftrace_graph_notrace_addr(unsigned long addr)
1045 {
1046 	int ret = 0;
1047 	struct ftrace_hash *notrace_hash;
1048 
1049 	preempt_disable_notrace();
1050 
1051 	/*
1052 	 * Have to open code "rcu_dereference_sched()" because the
1053 	 * function graph tracer can be called when RCU is not
1054 	 * "watching".
1055 	 * Protected with schedule_on_each_cpu(ftrace_sync)
1056 	 */
1057 	notrace_hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
1058 						 !preemptible());
1059 
1060 	if (ftrace_lookup_ip(notrace_hash, addr))
1061 		ret = 1;
1062 
1063 	preempt_enable_notrace();
1064 	return ret;
1065 }
1066 #else
1067 static inline int ftrace_graph_addr(unsigned long *task_var, struct ftrace_graph_ent *trace)
1068 {
1069 	return 1;
1070 }
1071 
1072 static inline int ftrace_graph_notrace_addr(unsigned long addr)
1073 {
1074 	return 0;
1075 }
1076 static inline void ftrace_graph_addr_finish(struct fgraph_ops *gops, struct ftrace_graph_ret *trace)
1077 { }
1078 #endif /* CONFIG_DYNAMIC_FTRACE */
1079 
1080 extern unsigned int fgraph_max_depth;
1081 extern bool fgraph_sleep_time;
1082 
1083 static inline bool
1084 ftrace_graph_ignore_func(struct fgraph_ops *gops, struct ftrace_graph_ent *trace)
1085 {
1086 	unsigned long *task_var = fgraph_get_task_var(gops);
1087 
1088 	/* trace it when it is-nested-in or is a function enabled. */
1089 	return !((*task_var & TRACE_GRAPH_FL) ||
1090 		 ftrace_graph_addr(task_var, trace)) ||
1091 		(trace->depth < 0) ||
1092 		(fgraph_max_depth && trace->depth >= fgraph_max_depth);
1093 }
1094 
1095 void fgraph_init_ops(struct ftrace_ops *dst_ops,
1096 		     struct ftrace_ops *src_ops);
1097 
1098 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
1099 static inline enum print_line_t
1100 print_graph_function_flags(struct trace_iterator *iter, u32 flags)
1101 {
1102 	return TRACE_TYPE_UNHANDLED;
1103 }
1104 static inline void free_fgraph_ops(struct trace_array *tr) { }
1105 /* ftrace_ops may not be defined */
1106 #define init_array_fgraph_ops(tr, ops) do { } while (0)
1107 #define allocate_fgraph_ops(tr, ops) ({ 0; })
1108 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
1109 
1110 extern struct list_head ftrace_pids;
1111 
1112 #ifdef CONFIG_FUNCTION_TRACER
1113 
1114 #define FTRACE_PID_IGNORE	-1
1115 #define FTRACE_PID_TRACE	-2
1116 
1117 struct ftrace_func_command {
1118 	struct list_head	list;
1119 	char			*name;
1120 	int			(*func)(struct trace_array *tr,
1121 					struct ftrace_hash *hash,
1122 					char *func, char *cmd,
1123 					char *params, int enable);
1124 };
1125 extern bool ftrace_filter_param __initdata;
1126 static inline int ftrace_trace_task(struct trace_array *tr)
1127 {
1128 	return this_cpu_read(tr->array_buffer.data->ftrace_ignore_pid) !=
1129 		FTRACE_PID_IGNORE;
1130 }
1131 extern int ftrace_is_dead(void);
1132 int ftrace_create_function_files(struct trace_array *tr,
1133 				 struct dentry *parent);
1134 void ftrace_destroy_function_files(struct trace_array *tr);
1135 int ftrace_allocate_ftrace_ops(struct trace_array *tr);
1136 void ftrace_free_ftrace_ops(struct trace_array *tr);
1137 void ftrace_init_global_array_ops(struct trace_array *tr);
1138 struct trace_array *trace_get_global_array(void);
1139 void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func);
1140 void ftrace_reset_array_ops(struct trace_array *tr);
1141 void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer);
1142 void ftrace_init_tracefs_toplevel(struct trace_array *tr,
1143 				  struct dentry *d_tracer);
1144 void ftrace_clear_pids(struct trace_array *tr);
1145 int init_function_trace(void);
1146 void ftrace_pid_follow_fork(struct trace_array *tr, bool enable);
1147 #else
1148 static inline int ftrace_trace_task(struct trace_array *tr)
1149 {
1150 	return 1;
1151 }
1152 static inline int ftrace_is_dead(void) { return 0; }
1153 static inline int
1154 ftrace_create_function_files(struct trace_array *tr,
1155 			     struct dentry *parent)
1156 {
1157 	return 0;
1158 }
1159 static inline int ftrace_allocate_ftrace_ops(struct trace_array *tr)
1160 {
1161 	return 0;
1162 }
1163 static inline void ftrace_free_ftrace_ops(struct trace_array *tr) { }
1164 static inline void ftrace_destroy_function_files(struct trace_array *tr) { }
1165 static inline __init void
1166 ftrace_init_global_array_ops(struct trace_array *tr) { }
1167 static inline void ftrace_reset_array_ops(struct trace_array *tr) { }
1168 static inline void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d) { }
1169 static inline void ftrace_init_tracefs_toplevel(struct trace_array *tr, struct dentry *d) { }
1170 static inline void ftrace_clear_pids(struct trace_array *tr) { }
1171 static inline int init_function_trace(void) { return 0; }
1172 static inline void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) { }
1173 /* ftace_func_t type is not defined, use macro instead of static inline */
1174 #define ftrace_init_array_ops(tr, func) do { } while (0)
1175 #endif /* CONFIG_FUNCTION_TRACER */
1176 
1177 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
1178 
1179 struct ftrace_probe_ops {
1180 	void			(*func)(unsigned long ip,
1181 					unsigned long parent_ip,
1182 					struct trace_array *tr,
1183 					struct ftrace_probe_ops *ops,
1184 					void *data);
1185 	int			(*init)(struct ftrace_probe_ops *ops,
1186 					struct trace_array *tr,
1187 					unsigned long ip, void *init_data,
1188 					void **data);
1189 	void			(*free)(struct ftrace_probe_ops *ops,
1190 					struct trace_array *tr,
1191 					unsigned long ip, void *data);
1192 	int			(*print)(struct seq_file *m,
1193 					 unsigned long ip,
1194 					 struct ftrace_probe_ops *ops,
1195 					 void *data);
1196 };
1197 
1198 struct ftrace_func_mapper;
1199 typedef int (*ftrace_mapper_func)(void *data);
1200 
1201 struct ftrace_func_mapper *allocate_ftrace_func_mapper(void);
1202 void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
1203 					   unsigned long ip);
1204 int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
1205 			       unsigned long ip, void *data);
1206 void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
1207 				   unsigned long ip);
1208 void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
1209 			     ftrace_mapper_func free_func);
1210 
1211 extern int
1212 register_ftrace_function_probe(char *glob, struct trace_array *tr,
1213 			       struct ftrace_probe_ops *ops, void *data);
1214 extern int
1215 unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
1216 				      struct ftrace_probe_ops *ops);
1217 extern void clear_ftrace_function_probes(struct trace_array *tr);
1218 
1219 int register_ftrace_command(struct ftrace_func_command *cmd);
1220 int unregister_ftrace_command(struct ftrace_func_command *cmd);
1221 
1222 void ftrace_create_filter_files(struct ftrace_ops *ops,
1223 				struct dentry *parent);
1224 void ftrace_destroy_filter_files(struct ftrace_ops *ops);
1225 
1226 extern int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
1227 			     int len, int reset);
1228 extern int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
1229 			      int len, int reset);
1230 #else
1231 struct ftrace_func_command;
1232 
1233 static inline __init int register_ftrace_command(struct ftrace_func_command *cmd)
1234 {
1235 	return -EINVAL;
1236 }
1237 static inline __init int unregister_ftrace_command(char *cmd_name)
1238 {
1239 	return -EINVAL;
1240 }
1241 static inline void clear_ftrace_function_probes(struct trace_array *tr)
1242 {
1243 }
1244 
1245 /*
1246  * The ops parameter passed in is usually undefined.
1247  * This must be a macro.
1248  */
1249 #define ftrace_create_filter_files(ops, parent) do { } while (0)
1250 #define ftrace_destroy_filter_files(ops) do { } while (0)
1251 #endif /* CONFIG_FUNCTION_TRACER && CONFIG_DYNAMIC_FTRACE */
1252 
1253 bool ftrace_event_is_function(struct trace_event_call *call);
1254 
1255 /*
1256  * struct trace_parser - servers for reading the user input separated by spaces
1257  * @cont: set if the input is not complete - no final space char was found
1258  * @buffer: holds the parsed user input
1259  * @idx: user input length
1260  * @size: buffer size
1261  */
1262 struct trace_parser {
1263 	bool		cont;
1264 	char		*buffer;
1265 	unsigned	idx;
1266 	unsigned	size;
1267 };
1268 
1269 static inline bool trace_parser_loaded(struct trace_parser *parser)
1270 {
1271 	return (parser->idx != 0);
1272 }
1273 
1274 static inline bool trace_parser_cont(struct trace_parser *parser)
1275 {
1276 	return parser->cont;
1277 }
1278 
1279 static inline void trace_parser_clear(struct trace_parser *parser)
1280 {
1281 	parser->cont = false;
1282 	parser->idx = 0;
1283 }
1284 
1285 extern int trace_parser_get_init(struct trace_parser *parser, int size);
1286 extern void trace_parser_put(struct trace_parser *parser);
1287 extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
1288 	size_t cnt, loff_t *ppos);
1289 
1290 /*
1291  * Only create function graph options if function graph is configured.
1292  */
1293 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1294 # define FGRAPH_FLAGS						\
1295 		C(DISPLAY_GRAPH,	"display-graph"),
1296 #else
1297 # define FGRAPH_FLAGS
1298 #endif
1299 
1300 #ifdef CONFIG_BRANCH_TRACER
1301 # define BRANCH_FLAGS					\
1302 		C(BRANCH,		"branch"),
1303 #else
1304 # define BRANCH_FLAGS
1305 #endif
1306 
1307 #ifdef CONFIG_FUNCTION_TRACER
1308 # define FUNCTION_FLAGS						\
1309 		C(FUNCTION,		"function-trace"),	\
1310 		C(FUNC_FORK,		"function-fork"),
1311 # define FUNCTION_DEFAULT_FLAGS		TRACE_ITER_FUNCTION
1312 #else
1313 # define FUNCTION_FLAGS
1314 # define FUNCTION_DEFAULT_FLAGS		0UL
1315 # define TRACE_ITER_FUNC_FORK		0UL
1316 #endif
1317 
1318 #ifdef CONFIG_STACKTRACE
1319 # define STACK_FLAGS				\
1320 		C(STACKTRACE,		"stacktrace"),
1321 #else
1322 # define STACK_FLAGS
1323 #endif
1324 
1325 /*
1326  * trace_iterator_flags is an enumeration that defines bit
1327  * positions into trace_flags that controls the output.
1328  *
1329  * NOTE: These bits must match the trace_options array in
1330  *       trace.c (this macro guarantees it).
1331  */
1332 #define TRACE_FLAGS						\
1333 		C(PRINT_PARENT,		"print-parent"),	\
1334 		C(SYM_OFFSET,		"sym-offset"),		\
1335 		C(SYM_ADDR,		"sym-addr"),		\
1336 		C(VERBOSE,		"verbose"),		\
1337 		C(RAW,			"raw"),			\
1338 		C(HEX,			"hex"),			\
1339 		C(BIN,			"bin"),			\
1340 		C(BLOCK,		"block"),		\
1341 		C(FIELDS,		"fields"),		\
1342 		C(PRINTK,		"trace_printk"),	\
1343 		C(ANNOTATE,		"annotate"),		\
1344 		C(USERSTACKTRACE,	"userstacktrace"),	\
1345 		C(SYM_USEROBJ,		"sym-userobj"),		\
1346 		C(PRINTK_MSGONLY,	"printk-msg-only"),	\
1347 		C(CONTEXT_INFO,		"context-info"),   /* Print pid/cpu/time */ \
1348 		C(LATENCY_FMT,		"latency-format"),	\
1349 		C(RECORD_CMD,		"record-cmd"),		\
1350 		C(RECORD_TGID,		"record-tgid"),		\
1351 		C(OVERWRITE,		"overwrite"),		\
1352 		C(STOP_ON_FREE,		"disable_on_free"),	\
1353 		C(IRQ_INFO,		"irq-info"),		\
1354 		C(MARKERS,		"markers"),		\
1355 		C(EVENT_FORK,		"event-fork"),		\
1356 		C(TRACE_PRINTK,		"trace_printk_dest"),	\
1357 		C(PAUSE_ON_TRACE,	"pause-on-trace"),	\
1358 		C(HASH_PTR,		"hash-ptr"),	/* Print hashed pointer */ \
1359 		FUNCTION_FLAGS					\
1360 		FGRAPH_FLAGS					\
1361 		STACK_FLAGS					\
1362 		BRANCH_FLAGS
1363 
1364 /*
1365  * By defining C, we can make TRACE_FLAGS a list of bit names
1366  * that will define the bits for the flag masks.
1367  */
1368 #undef C
1369 #define C(a, b) TRACE_ITER_##a##_BIT
1370 
1371 enum trace_iterator_bits {
1372 	TRACE_FLAGS
1373 	/* Make sure we don't go more than we have bits for */
1374 	TRACE_ITER_LAST_BIT
1375 };
1376 
1377 /*
1378  * By redefining C, we can make TRACE_FLAGS a list of masks that
1379  * use the bits as defined above.
1380  */
1381 #undef C
1382 #define C(a, b) TRACE_ITER_##a = (1 << TRACE_ITER_##a##_BIT)
1383 
1384 enum trace_iterator_flags { TRACE_FLAGS };
1385 
1386 /*
1387  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
1388  * control the output of kernel symbols.
1389  */
1390 #define TRACE_ITER_SYM_MASK \
1391 	(TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
1392 
1393 extern struct tracer nop_trace;
1394 
1395 #ifdef CONFIG_BRANCH_TRACER
1396 extern int enable_branch_tracing(struct trace_array *tr);
1397 extern void disable_branch_tracing(void);
1398 static inline int trace_branch_enable(struct trace_array *tr)
1399 {
1400 	if (tr->trace_flags & TRACE_ITER_BRANCH)
1401 		return enable_branch_tracing(tr);
1402 	return 0;
1403 }
1404 static inline void trace_branch_disable(void)
1405 {
1406 	/* due to races, always disable */
1407 	disable_branch_tracing();
1408 }
1409 #else
1410 static inline int trace_branch_enable(struct trace_array *tr)
1411 {
1412 	return 0;
1413 }
1414 static inline void trace_branch_disable(void)
1415 {
1416 }
1417 #endif /* CONFIG_BRANCH_TRACER */
1418 
1419 /* set ring buffers to default size if not already done so */
1420 int tracing_update_buffers(struct trace_array *tr);
1421 
1422 union trace_synth_field {
1423 	u8				as_u8;
1424 	u16				as_u16;
1425 	u32				as_u32;
1426 	u64				as_u64;
1427 	struct trace_dynamic_info	as_dynamic;
1428 };
1429 
1430 struct ftrace_event_field {
1431 	struct list_head	link;
1432 	const char		*name;
1433 	const char		*type;
1434 	int			filter_type;
1435 	int			offset;
1436 	int			size;
1437 	unsigned int		is_signed:1;
1438 	unsigned int		needs_test:1;
1439 	int			len;
1440 };
1441 
1442 struct prog_entry;
1443 
1444 struct event_filter {
1445 	struct prog_entry __rcu	*prog;
1446 	char			*filter_string;
1447 };
1448 
1449 struct event_subsystem {
1450 	struct list_head	list;
1451 	const char		*name;
1452 	struct event_filter	*filter;
1453 	int			ref_count;
1454 };
1455 
1456 struct trace_subsystem_dir {
1457 	struct list_head		list;
1458 	struct event_subsystem		*subsystem;
1459 	struct trace_array		*tr;
1460 	struct eventfs_inode		*ei;
1461 	int				ref_count;
1462 	int				nr_events;
1463 };
1464 
1465 void trace_buffer_unlock_commit_regs(struct trace_array *tr,
1466 				     struct trace_buffer *buffer,
1467 				     struct ring_buffer_event *event,
1468 				     unsigned int trcace_ctx,
1469 				     struct pt_regs *regs);
1470 
1471 static inline void trace_buffer_unlock_commit(struct trace_array *tr,
1472 					      struct trace_buffer *buffer,
1473 					      struct ring_buffer_event *event,
1474 					      unsigned int trace_ctx)
1475 {
1476 	trace_buffer_unlock_commit_regs(tr, buffer, event, trace_ctx, NULL);
1477 }
1478 
1479 DECLARE_PER_CPU(bool, trace_taskinfo_save);
1480 int trace_save_cmdline(struct task_struct *tsk);
1481 int trace_create_savedcmd(void);
1482 int trace_alloc_tgid_map(void);
1483 void trace_free_saved_cmdlines_buffer(void);
1484 
1485 extern const struct file_operations tracing_saved_cmdlines_fops;
1486 extern const struct file_operations tracing_saved_tgids_fops;
1487 extern const struct file_operations tracing_saved_cmdlines_size_fops;
1488 
1489 DECLARE_PER_CPU(struct ring_buffer_event *, trace_buffered_event);
1490 DECLARE_PER_CPU(int, trace_buffered_event_cnt);
1491 void trace_buffered_event_disable(void);
1492 void trace_buffered_event_enable(void);
1493 
1494 void early_enable_events(struct trace_array *tr, char *buf, bool disable_first);
1495 
1496 static inline void
1497 __trace_event_discard_commit(struct trace_buffer *buffer,
1498 			     struct ring_buffer_event *event)
1499 {
1500 	if (this_cpu_read(trace_buffered_event) == event) {
1501 		/* Simply release the temp buffer and enable preemption */
1502 		this_cpu_dec(trace_buffered_event_cnt);
1503 		preempt_enable_notrace();
1504 		return;
1505 	}
1506 	/* ring_buffer_discard_commit() enables preemption */
1507 	ring_buffer_discard_commit(buffer, event);
1508 }
1509 
1510 /*
1511  * Helper function for event_trigger_unlock_commit{_regs}().
1512  * If there are event triggers attached to this event that requires
1513  * filtering against its fields, then they will be called as the
1514  * entry already holds the field information of the current event.
1515  *
1516  * It also checks if the event should be discarded or not.
1517  * It is to be discarded if the event is soft disabled and the
1518  * event was only recorded to process triggers, or if the event
1519  * filter is active and this event did not match the filters.
1520  *
1521  * Returns true if the event is discarded, false otherwise.
1522  */
1523 static inline bool
1524 __event_trigger_test_discard(struct trace_event_file *file,
1525 			     struct trace_buffer *buffer,
1526 			     struct ring_buffer_event *event,
1527 			     void *entry,
1528 			     enum event_trigger_type *tt)
1529 {
1530 	unsigned long eflags = file->flags;
1531 
1532 	if (eflags & EVENT_FILE_FL_TRIGGER_COND)
1533 		*tt = event_triggers_call(file, buffer, entry, event);
1534 
1535 	if (likely(!(file->flags & (EVENT_FILE_FL_SOFT_DISABLED |
1536 				    EVENT_FILE_FL_FILTERED |
1537 				    EVENT_FILE_FL_PID_FILTER))))
1538 		return false;
1539 
1540 	if (file->flags & EVENT_FILE_FL_SOFT_DISABLED)
1541 		goto discard;
1542 
1543 	if (file->flags & EVENT_FILE_FL_FILTERED &&
1544 	    !filter_match_preds(file->filter, entry))
1545 		goto discard;
1546 
1547 	if ((file->flags & EVENT_FILE_FL_PID_FILTER) &&
1548 	    trace_event_ignore_this_pid(file))
1549 		goto discard;
1550 
1551 	return false;
1552  discard:
1553 	__trace_event_discard_commit(buffer, event);
1554 	return true;
1555 }
1556 
1557 /**
1558  * event_trigger_unlock_commit - handle triggers and finish event commit
1559  * @file: The file pointer associated with the event
1560  * @buffer: The ring buffer that the event is being written to
1561  * @event: The event meta data in the ring buffer
1562  * @entry: The event itself
1563  * @trace_ctx: The tracing context flags.
1564  *
1565  * This is a helper function to handle triggers that require data
1566  * from the event itself. It also tests the event against filters and
1567  * if the event is soft disabled and should be discarded.
1568  */
1569 static inline void
1570 event_trigger_unlock_commit(struct trace_event_file *file,
1571 			    struct trace_buffer *buffer,
1572 			    struct ring_buffer_event *event,
1573 			    void *entry, unsigned int trace_ctx)
1574 {
1575 	enum event_trigger_type tt = ETT_NONE;
1576 
1577 	if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1578 		trace_buffer_unlock_commit(file->tr, buffer, event, trace_ctx);
1579 
1580 	if (tt)
1581 		event_triggers_post_call(file, tt);
1582 }
1583 
1584 #define FILTER_PRED_INVALID	((unsigned short)-1)
1585 #define FILTER_PRED_IS_RIGHT	(1 << 15)
1586 #define FILTER_PRED_FOLD	(1 << 15)
1587 
1588 /*
1589  * The max preds is the size of unsigned short with
1590  * two flags at the MSBs. One bit is used for both the IS_RIGHT
1591  * and FOLD flags. The other is reserved.
1592  *
1593  * 2^14 preds is way more than enough.
1594  */
1595 #define MAX_FILTER_PRED		16384
1596 
1597 struct filter_pred;
1598 struct regex;
1599 
1600 typedef int (*regex_match_func)(char *str, struct regex *r, int len);
1601 
1602 enum regex_type {
1603 	MATCH_FULL = 0,
1604 	MATCH_FRONT_ONLY,
1605 	MATCH_MIDDLE_ONLY,
1606 	MATCH_END_ONLY,
1607 	MATCH_GLOB,
1608 	MATCH_INDEX,
1609 };
1610 
1611 struct regex {
1612 	char			pattern[MAX_FILTER_STR_VAL];
1613 	int			len;
1614 	int			field_len;
1615 	regex_match_func	match;
1616 };
1617 
1618 static inline bool is_string_field(struct ftrace_event_field *field)
1619 {
1620 	return field->filter_type == FILTER_DYN_STRING ||
1621 	       field->filter_type == FILTER_RDYN_STRING ||
1622 	       field->filter_type == FILTER_STATIC_STRING ||
1623 	       field->filter_type == FILTER_PTR_STRING ||
1624 	       field->filter_type == FILTER_COMM;
1625 }
1626 
1627 static inline bool is_function_field(struct ftrace_event_field *field)
1628 {
1629 	return field->filter_type == FILTER_TRACE_FN;
1630 }
1631 
1632 extern enum regex_type
1633 filter_parse_regex(char *buff, int len, char **search, int *not);
1634 extern void print_event_filter(struct trace_event_file *file,
1635 			       struct trace_seq *s);
1636 extern int apply_event_filter(struct trace_event_file *file,
1637 			      char *filter_string);
1638 extern int apply_subsystem_event_filter(struct trace_subsystem_dir *dir,
1639 					char *filter_string);
1640 extern void print_subsystem_event_filter(struct event_subsystem *system,
1641 					 struct trace_seq *s);
1642 extern int filter_assign_type(const char *type);
1643 extern int create_event_filter(struct trace_array *tr,
1644 			       struct trace_event_call *call,
1645 			       char *filter_str, bool set_str,
1646 			       struct event_filter **filterp);
1647 extern void free_event_filter(struct event_filter *filter);
1648 
1649 struct ftrace_event_field *
1650 trace_find_event_field(struct trace_event_call *call, char *name);
1651 
1652 extern void trace_event_enable_cmd_record(bool enable);
1653 extern void trace_event_enable_tgid_record(bool enable);
1654 
1655 extern int event_trace_init(void);
1656 extern int init_events(void);
1657 extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
1658 extern int event_trace_del_tracer(struct trace_array *tr);
1659 extern void __trace_early_add_events(struct trace_array *tr);
1660 
1661 extern struct trace_event_file *__find_event_file(struct trace_array *tr,
1662 						  const char *system,
1663 						  const char *event);
1664 extern struct trace_event_file *find_event_file(struct trace_array *tr,
1665 						const char *system,
1666 						const char *event);
1667 
1668 static inline void *event_file_data(struct file *filp)
1669 {
1670 	return READ_ONCE(file_inode(filp)->i_private);
1671 }
1672 
1673 extern struct mutex event_mutex;
1674 extern struct list_head ftrace_events;
1675 
1676 /*
1677  * When the trace_event_file is the filp->i_private pointer,
1678  * it must be taken under the event_mutex lock, and then checked
1679  * if the EVENT_FILE_FL_FREED flag is set. If it is, then the
1680  * data pointed to by the trace_event_file can not be trusted.
1681  *
1682  * Use the event_file_file() to access the trace_event_file from
1683  * the filp the first time under the event_mutex and check for
1684  * NULL. If it is needed to be retrieved again and the event_mutex
1685  * is still held, then the event_file_data() can be used and it
1686  * is guaranteed to be valid.
1687  */
1688 static inline struct trace_event_file *event_file_file(struct file *filp)
1689 {
1690 	struct trace_event_file *file;
1691 
1692 	lockdep_assert_held(&event_mutex);
1693 	file = READ_ONCE(file_inode(filp)->i_private);
1694 	if (!file || file->flags & EVENT_FILE_FL_FREED)
1695 		return NULL;
1696 	return file;
1697 }
1698 
1699 extern const struct file_operations event_trigger_fops;
1700 extern const struct file_operations event_hist_fops;
1701 extern const struct file_operations event_hist_debug_fops;
1702 extern const struct file_operations event_inject_fops;
1703 
1704 #ifdef CONFIG_HIST_TRIGGERS
1705 extern int register_trigger_hist_cmd(void);
1706 extern int register_trigger_hist_enable_disable_cmds(void);
1707 #else
1708 static inline int register_trigger_hist_cmd(void) { return 0; }
1709 static inline int register_trigger_hist_enable_disable_cmds(void) { return 0; }
1710 #endif
1711 
1712 extern int register_trigger_cmds(void);
1713 extern void clear_event_triggers(struct trace_array *tr);
1714 
1715 enum {
1716 	EVENT_TRIGGER_FL_PROBE		= BIT(0),
1717 };
1718 
1719 struct event_trigger_data {
1720 	unsigned long			count;
1721 	int				ref;
1722 	int				flags;
1723 	struct event_trigger_ops	*ops;
1724 	struct event_command		*cmd_ops;
1725 	struct event_filter __rcu	*filter;
1726 	char				*filter_str;
1727 	void				*private_data;
1728 	bool				paused;
1729 	bool				paused_tmp;
1730 	struct list_head		list;
1731 	char				*name;
1732 	struct list_head		named_list;
1733 	struct event_trigger_data	*named_data;
1734 };
1735 
1736 /* Avoid typos */
1737 #define ENABLE_EVENT_STR	"enable_event"
1738 #define DISABLE_EVENT_STR	"disable_event"
1739 #define ENABLE_HIST_STR		"enable_hist"
1740 #define DISABLE_HIST_STR	"disable_hist"
1741 
1742 struct enable_trigger_data {
1743 	struct trace_event_file		*file;
1744 	bool				enable;
1745 	bool				hist;
1746 };
1747 
1748 extern int event_enable_trigger_print(struct seq_file *m,
1749 				      struct event_trigger_data *data);
1750 extern void event_enable_trigger_free(struct event_trigger_data *data);
1751 extern int event_enable_trigger_parse(struct event_command *cmd_ops,
1752 				      struct trace_event_file *file,
1753 				      char *glob, char *cmd,
1754 				      char *param_and_filter);
1755 extern int event_enable_register_trigger(char *glob,
1756 					 struct event_trigger_data *data,
1757 					 struct trace_event_file *file);
1758 extern void event_enable_unregister_trigger(char *glob,
1759 					    struct event_trigger_data *test,
1760 					    struct trace_event_file *file);
1761 extern void trigger_data_free(struct event_trigger_data *data);
1762 extern int event_trigger_init(struct event_trigger_data *data);
1763 extern int trace_event_trigger_enable_disable(struct trace_event_file *file,
1764 					      int trigger_enable);
1765 extern void update_cond_flag(struct trace_event_file *file);
1766 extern int set_trigger_filter(char *filter_str,
1767 			      struct event_trigger_data *trigger_data,
1768 			      struct trace_event_file *file);
1769 extern struct event_trigger_data *find_named_trigger(const char *name);
1770 extern bool is_named_trigger(struct event_trigger_data *test);
1771 extern int save_named_trigger(const char *name,
1772 			      struct event_trigger_data *data);
1773 extern void del_named_trigger(struct event_trigger_data *data);
1774 extern void pause_named_trigger(struct event_trigger_data *data);
1775 extern void unpause_named_trigger(struct event_trigger_data *data);
1776 extern void set_named_trigger_data(struct event_trigger_data *data,
1777 				   struct event_trigger_data *named_data);
1778 extern struct event_trigger_data *
1779 get_named_trigger_data(struct event_trigger_data *data);
1780 extern int register_event_command(struct event_command *cmd);
1781 extern int unregister_event_command(struct event_command *cmd);
1782 extern int register_trigger_hist_enable_disable_cmds(void);
1783 extern bool event_trigger_check_remove(const char *glob);
1784 extern bool event_trigger_empty_param(const char *param);
1785 extern int event_trigger_separate_filter(char *param_and_filter, char **param,
1786 					 char **filter, bool param_required);
1787 extern struct event_trigger_data *
1788 event_trigger_alloc(struct event_command *cmd_ops,
1789 		    char *cmd,
1790 		    char *param,
1791 		    void *private_data);
1792 extern int event_trigger_parse_num(char *trigger,
1793 				   struct event_trigger_data *trigger_data);
1794 extern int event_trigger_set_filter(struct event_command *cmd_ops,
1795 				    struct trace_event_file *file,
1796 				    char *param,
1797 				    struct event_trigger_data *trigger_data);
1798 extern void event_trigger_reset_filter(struct event_command *cmd_ops,
1799 				       struct event_trigger_data *trigger_data);
1800 extern int event_trigger_register(struct event_command *cmd_ops,
1801 				  struct trace_event_file *file,
1802 				  char *glob,
1803 				  struct event_trigger_data *trigger_data);
1804 extern void event_trigger_unregister(struct event_command *cmd_ops,
1805 				     struct trace_event_file *file,
1806 				     char *glob,
1807 				     struct event_trigger_data *trigger_data);
1808 
1809 extern void event_file_get(struct trace_event_file *file);
1810 extern void event_file_put(struct trace_event_file *file);
1811 
1812 /**
1813  * struct event_trigger_ops - callbacks for trace event triggers
1814  *
1815  * The methods in this structure provide per-event trigger hooks for
1816  * various trigger operations.
1817  *
1818  * The @init and @free methods are used during trigger setup and
1819  * teardown, typically called from an event_command's @parse()
1820  * function implementation.
1821  *
1822  * The @print method is used to print the trigger spec.
1823  *
1824  * The @trigger method is the function that actually implements the
1825  * trigger and is called in the context of the triggering event
1826  * whenever that event occurs.
1827  *
1828  * All the methods below, except for @init() and @free(), must be
1829  * implemented.
1830  *
1831  * @trigger: The trigger 'probe' function called when the triggering
1832  *	event occurs.  The data passed into this callback is the data
1833  *	that was supplied to the event_command @reg() function that
1834  *	registered the trigger (see struct event_command) along with
1835  *	the trace record, rec.
1836  *
1837  * @init: An optional initialization function called for the trigger
1838  *	when the trigger is registered (via the event_command reg()
1839  *	function).  This can be used to perform per-trigger
1840  *	initialization such as incrementing a per-trigger reference
1841  *	count, for instance.  This is usually implemented by the
1842  *	generic utility function @event_trigger_init() (see
1843  *	trace_event_triggers.c).
1844  *
1845  * @free: An optional de-initialization function called for the
1846  *	trigger when the trigger is unregistered (via the
1847  *	event_command @reg() function).  This can be used to perform
1848  *	per-trigger de-initialization such as decrementing a
1849  *	per-trigger reference count and freeing corresponding trigger
1850  *	data, for instance.  This is usually implemented by the
1851  *	generic utility function @event_trigger_free() (see
1852  *	trace_event_triggers.c).
1853  *
1854  * @print: The callback function invoked to have the trigger print
1855  *	itself.  This is usually implemented by a wrapper function
1856  *	that calls the generic utility function @event_trigger_print()
1857  *	(see trace_event_triggers.c).
1858  */
1859 struct event_trigger_ops {
1860 	void			(*trigger)(struct event_trigger_data *data,
1861 					   struct trace_buffer *buffer,
1862 					   void *rec,
1863 					   struct ring_buffer_event *rbe);
1864 	int			(*init)(struct event_trigger_data *data);
1865 	void			(*free)(struct event_trigger_data *data);
1866 	int			(*print)(struct seq_file *m,
1867 					 struct event_trigger_data *data);
1868 };
1869 
1870 /**
1871  * struct event_command - callbacks and data members for event commands
1872  *
1873  * Event commands are invoked by users by writing the command name
1874  * into the 'trigger' file associated with a trace event.  The
1875  * parameters associated with a specific invocation of an event
1876  * command are used to create an event trigger instance, which is
1877  * added to the list of trigger instances associated with that trace
1878  * event.  When the event is hit, the set of triggers associated with
1879  * that event is invoked.
1880  *
1881  * The data members in this structure provide per-event command data
1882  * for various event commands.
1883  *
1884  * All the data members below, except for @post_trigger, must be set
1885  * for each event command.
1886  *
1887  * @name: The unique name that identifies the event command.  This is
1888  *	the name used when setting triggers via trigger files.
1889  *
1890  * @trigger_type: A unique id that identifies the event command
1891  *	'type'.  This value has two purposes, the first to ensure that
1892  *	only one trigger of the same type can be set at a given time
1893  *	for a particular event e.g. it doesn't make sense to have both
1894  *	a traceon and traceoff trigger attached to a single event at
1895  *	the same time, so traceon and traceoff have the same type
1896  *	though they have different names.  The @trigger_type value is
1897  *	also used as a bit value for deferring the actual trigger
1898  *	action until after the current event is finished.  Some
1899  *	commands need to do this if they themselves log to the trace
1900  *	buffer (see the @post_trigger() member below).  @trigger_type
1901  *	values are defined by adding new values to the trigger_type
1902  *	enum in include/linux/trace_events.h.
1903  *
1904  * @flags: See the enum event_command_flags below.
1905  *
1906  * All the methods below, except for @set_filter() and @unreg_all(),
1907  * must be implemented.
1908  *
1909  * @parse: The callback function responsible for parsing and
1910  *	registering the trigger written to the 'trigger' file by the
1911  *	user.  It allocates the trigger instance and registers it with
1912  *	the appropriate trace event.  It makes use of the other
1913  *	event_command callback functions to orchestrate this, and is
1914  *	usually implemented by the generic utility function
1915  *	@event_trigger_callback() (see trace_event_triggers.c).
1916  *
1917  * @reg: Adds the trigger to the list of triggers associated with the
1918  *	event, and enables the event trigger itself, after
1919  *	initializing it (via the event_trigger_ops @init() function).
1920  *	This is also where commands can use the @trigger_type value to
1921  *	make the decision as to whether or not multiple instances of
1922  *	the trigger should be allowed.  This is usually implemented by
1923  *	the generic utility function @register_trigger() (see
1924  *	trace_event_triggers.c).
1925  *
1926  * @unreg: Removes the trigger from the list of triggers associated
1927  *	with the event, and disables the event trigger itself, after
1928  *	initializing it (via the event_trigger_ops @free() function).
1929  *	This is usually implemented by the generic utility function
1930  *	@unregister_trigger() (see trace_event_triggers.c).
1931  *
1932  * @unreg_all: An optional function called to remove all the triggers
1933  *	from the list of triggers associated with the event.  Called
1934  *	when a trigger file is opened in truncate mode.
1935  *
1936  * @set_filter: An optional function called to parse and set a filter
1937  *	for the trigger.  If no @set_filter() method is set for the
1938  *	event command, filters set by the user for the command will be
1939  *	ignored.  This is usually implemented by the generic utility
1940  *	function @set_trigger_filter() (see trace_event_triggers.c).
1941  *
1942  * @get_trigger_ops: The callback function invoked to retrieve the
1943  *	event_trigger_ops implementation associated with the command.
1944  *	This callback function allows a single event_command to
1945  *	support multiple trigger implementations via different sets of
1946  *	event_trigger_ops, depending on the value of the @param
1947  *	string.
1948  */
1949 struct event_command {
1950 	struct list_head	list;
1951 	char			*name;
1952 	enum event_trigger_type	trigger_type;
1953 	int			flags;
1954 	int			(*parse)(struct event_command *cmd_ops,
1955 					 struct trace_event_file *file,
1956 					 char *glob, char *cmd,
1957 					 char *param_and_filter);
1958 	int			(*reg)(char *glob,
1959 				       struct event_trigger_data *data,
1960 				       struct trace_event_file *file);
1961 	void			(*unreg)(char *glob,
1962 					 struct event_trigger_data *data,
1963 					 struct trace_event_file *file);
1964 	void			(*unreg_all)(struct trace_event_file *file);
1965 	int			(*set_filter)(char *filter_str,
1966 					      struct event_trigger_data *data,
1967 					      struct trace_event_file *file);
1968 	struct event_trigger_ops *(*get_trigger_ops)(char *cmd, char *param);
1969 };
1970 
1971 /**
1972  * enum event_command_flags - flags for struct event_command
1973  *
1974  * @POST_TRIGGER: A flag that says whether or not this command needs
1975  *	to have its action delayed until after the current event has
1976  *	been closed.  Some triggers need to avoid being invoked while
1977  *	an event is currently in the process of being logged, since
1978  *	the trigger may itself log data into the trace buffer.  Thus
1979  *	we make sure the current event is committed before invoking
1980  *	those triggers.  To do that, the trigger invocation is split
1981  *	in two - the first part checks the filter using the current
1982  *	trace record; if a command has the @post_trigger flag set, it
1983  *	sets a bit for itself in the return value, otherwise it
1984  *	directly invokes the trigger.  Once all commands have been
1985  *	either invoked or set their return flag, the current record is
1986  *	either committed or discarded.  At that point, if any commands
1987  *	have deferred their triggers, those commands are finally
1988  *	invoked following the close of the current event.  In other
1989  *	words, if the event_trigger_ops @func() probe implementation
1990  *	itself logs to the trace buffer, this flag should be set,
1991  *	otherwise it can be left unspecified.
1992  *
1993  * @NEEDS_REC: A flag that says whether or not this command needs
1994  *	access to the trace record in order to perform its function,
1995  *	regardless of whether or not it has a filter associated with
1996  *	it (filters make a trigger require access to the trace record
1997  *	but are not always present).
1998  */
1999 enum event_command_flags {
2000 	EVENT_CMD_FL_POST_TRIGGER	= 1,
2001 	EVENT_CMD_FL_NEEDS_REC		= 2,
2002 };
2003 
2004 static inline bool event_command_post_trigger(struct event_command *cmd_ops)
2005 {
2006 	return cmd_ops->flags & EVENT_CMD_FL_POST_TRIGGER;
2007 }
2008 
2009 static inline bool event_command_needs_rec(struct event_command *cmd_ops)
2010 {
2011 	return cmd_ops->flags & EVENT_CMD_FL_NEEDS_REC;
2012 }
2013 
2014 extern int trace_event_enable_disable(struct trace_event_file *file,
2015 				      int enable, int soft_disable);
2016 extern int tracing_alloc_snapshot(void);
2017 extern void tracing_snapshot_cond(struct trace_array *tr, void *cond_data);
2018 extern int tracing_snapshot_cond_enable(struct trace_array *tr, void *cond_data, cond_update_fn_t update);
2019 
2020 extern int tracing_snapshot_cond_disable(struct trace_array *tr);
2021 extern void *tracing_cond_snapshot_data(struct trace_array *tr);
2022 
2023 extern const char *__start___trace_bprintk_fmt[];
2024 extern const char *__stop___trace_bprintk_fmt[];
2025 
2026 extern const char *__start___tracepoint_str[];
2027 extern const char *__stop___tracepoint_str[];
2028 
2029 void trace_printk_control(bool enabled);
2030 void trace_printk_start_comm(void);
2031 int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set);
2032 int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled);
2033 
2034 /* Used from boot time tracer */
2035 extern int trace_set_options(struct trace_array *tr, char *option);
2036 extern int tracing_set_tracer(struct trace_array *tr, const char *buf);
2037 extern ssize_t tracing_resize_ring_buffer(struct trace_array *tr,
2038 					  unsigned long size, int cpu_id);
2039 extern int tracing_set_cpumask(struct trace_array *tr,
2040 				cpumask_var_t tracing_cpumask_new);
2041 
2042 
2043 #define MAX_EVENT_NAME_LEN	64
2044 
2045 extern ssize_t trace_parse_run_command(struct file *file,
2046 		const char __user *buffer, size_t count, loff_t *ppos,
2047 		int (*createfn)(const char *));
2048 
2049 extern unsigned int err_pos(char *cmd, const char *str);
2050 extern void tracing_log_err(struct trace_array *tr,
2051 			    const char *loc, const char *cmd,
2052 			    const char **errs, u8 type, u16 pos);
2053 
2054 /*
2055  * Normal trace_printk() and friends allocates special buffers
2056  * to do the manipulation, as well as saves the print formats
2057  * into sections to display. But the trace infrastructure wants
2058  * to use these without the added overhead at the price of being
2059  * a bit slower (used mainly for warnings, where we don't care
2060  * about performance). The internal_trace_puts() is for such
2061  * a purpose.
2062  */
2063 #define internal_trace_puts(str) __trace_puts(_THIS_IP_, str, strlen(str))
2064 
2065 #undef FTRACE_ENTRY
2066 #define FTRACE_ENTRY(call, struct_name, id, tstruct, print)	\
2067 	extern struct trace_event_call					\
2068 	__aligned(4) event_##call;
2069 #undef FTRACE_ENTRY_DUP
2070 #define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print)	\
2071 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
2072 #undef FTRACE_ENTRY_PACKED
2073 #define FTRACE_ENTRY_PACKED(call, struct_name, id, tstruct, print) \
2074 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
2075 
2076 #include "trace_entries.h"
2077 
2078 #if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_FUNCTION_TRACER)
2079 int perf_ftrace_event_register(struct trace_event_call *call,
2080 			       enum trace_reg type, void *data);
2081 #else
2082 #define perf_ftrace_event_register NULL
2083 #endif
2084 
2085 #ifdef CONFIG_FTRACE_SYSCALLS
2086 void init_ftrace_syscalls(void);
2087 const char *get_syscall_name(int syscall);
2088 #else
2089 static inline void init_ftrace_syscalls(void) { }
2090 static inline const char *get_syscall_name(int syscall)
2091 {
2092 	return NULL;
2093 }
2094 #endif
2095 
2096 #ifdef CONFIG_EVENT_TRACING
2097 void trace_event_init(void);
2098 void trace_event_eval_update(struct trace_eval_map **map, int len);
2099 /* Used from boot time tracer */
2100 extern int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set);
2101 extern int trigger_process_regex(struct trace_event_file *file, char *buff);
2102 #else
2103 static inline void __init trace_event_init(void) { }
2104 static inline void trace_event_eval_update(struct trace_eval_map **map, int len) { }
2105 #endif
2106 
2107 #ifdef CONFIG_TRACER_SNAPSHOT
2108 void tracing_snapshot_instance(struct trace_array *tr);
2109 int tracing_alloc_snapshot_instance(struct trace_array *tr);
2110 int tracing_arm_snapshot(struct trace_array *tr);
2111 void tracing_disarm_snapshot(struct trace_array *tr);
2112 #else
2113 static inline void tracing_snapshot_instance(struct trace_array *tr) { }
2114 static inline int tracing_alloc_snapshot_instance(struct trace_array *tr)
2115 {
2116 	return 0;
2117 }
2118 static inline int tracing_arm_snapshot(struct trace_array *tr) { return 0; }
2119 static inline void tracing_disarm_snapshot(struct trace_array *tr) { }
2120 #endif
2121 
2122 #ifdef CONFIG_PREEMPT_TRACER
2123 void tracer_preempt_on(unsigned long a0, unsigned long a1);
2124 void tracer_preempt_off(unsigned long a0, unsigned long a1);
2125 #else
2126 static inline void tracer_preempt_on(unsigned long a0, unsigned long a1) { }
2127 static inline void tracer_preempt_off(unsigned long a0, unsigned long a1) { }
2128 #endif
2129 #ifdef CONFIG_IRQSOFF_TRACER
2130 void tracer_hardirqs_on(unsigned long a0, unsigned long a1);
2131 void tracer_hardirqs_off(unsigned long a0, unsigned long a1);
2132 #else
2133 static inline void tracer_hardirqs_on(unsigned long a0, unsigned long a1) { }
2134 static inline void tracer_hardirqs_off(unsigned long a0, unsigned long a1) { }
2135 #endif
2136 
2137 /*
2138  * Reset the state of the trace_iterator so that it can read consumed data.
2139  * Normally, the trace_iterator is used for reading the data when it is not
2140  * consumed, and must retain state.
2141  */
2142 static __always_inline void trace_iterator_reset(struct trace_iterator *iter)
2143 {
2144 	memset_startat(iter, 0, seq);
2145 	iter->pos = -1;
2146 }
2147 
2148 /* Check the name is good for event/group/fields */
2149 static inline bool __is_good_name(const char *name, bool hash_ok)
2150 {
2151 	if (!isalpha(*name) && *name != '_' && (!hash_ok || *name != '-'))
2152 		return false;
2153 	while (*++name != '\0') {
2154 		if (!isalpha(*name) && !isdigit(*name) && *name != '_' &&
2155 		    (!hash_ok || *name != '-'))
2156 			return false;
2157 	}
2158 	return true;
2159 }
2160 
2161 /* Check the name is good for event/group/fields */
2162 static inline bool is_good_name(const char *name)
2163 {
2164 	return __is_good_name(name, false);
2165 }
2166 
2167 /* Check the name is good for system */
2168 static inline bool is_good_system_name(const char *name)
2169 {
2170 	return __is_good_name(name, true);
2171 }
2172 
2173 /* Convert certain expected symbols into '_' when generating event names */
2174 static inline void sanitize_event_name(char *name)
2175 {
2176 	while (*name++ != '\0')
2177 		if (*name == ':' || *name == '.')
2178 			*name = '_';
2179 }
2180 
2181 /*
2182  * This is a generic way to read and write a u64 value from a file in tracefs.
2183  *
2184  * The value is stored on the variable pointed by *val. The value needs
2185  * to be at least *min and at most *max. The write is protected by an
2186  * existing *lock.
2187  */
2188 struct trace_min_max_param {
2189 	struct mutex	*lock;
2190 	u64		*val;
2191 	u64		*min;
2192 	u64		*max;
2193 };
2194 
2195 #define U64_STR_SIZE		24	/* 20 digits max */
2196 
2197 extern const struct file_operations trace_min_max_fops;
2198 
2199 #ifdef CONFIG_RV
2200 extern int rv_init_interface(void);
2201 #else
2202 static inline int rv_init_interface(void)
2203 {
2204 	return 0;
2205 }
2206 #endif
2207 
2208 /*
2209  * This is used only to distinguish
2210  * function address from trampoline code.
2211  * So this value has no meaning.
2212  */
2213 #define FTRACE_TRAMPOLINE_MARKER  ((unsigned long) INT_MAX)
2214 
2215 #endif /* _LINUX_KERNEL_TRACE_H */
2216