xref: /linux/kernel/trace/trace.h (revision 55d0969c451159cff86949b38c39171cab962069)
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 /*
81  * For backward compatibility, older user space expects to see the
82  * kernel_stack event with a fixed size caller field. But today the fix
83  * size is ignored by the kernel, and the real structure is dynamic.
84  * Expose to user space: "unsigned long caller[8];" but the real structure
85  * will be "unsigned long caller[] __counted_by(size)"
86  */
87 #undef __stack_array
88 #define __stack_array(type, item, size, field)		type item[] __counted_by(field);
89 
90 #undef __array_desc
91 #define __array_desc(type, container, item, size)
92 
93 #undef __dynamic_array
94 #define __dynamic_array(type, item)	type	item[];
95 
96 #undef __rel_dynamic_array
97 #define __rel_dynamic_array(type, item)	type	item[];
98 
99 #undef F_STRUCT
100 #define F_STRUCT(args...)		args
101 
102 #undef FTRACE_ENTRY
103 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print)		\
104 	struct struct_name {						\
105 		struct trace_entry	ent;				\
106 		tstruct							\
107 	}
108 
109 #undef FTRACE_ENTRY_DUP
110 #define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk)
111 
112 #undef FTRACE_ENTRY_REG
113 #define FTRACE_ENTRY_REG(name, struct_name, id, tstruct, print,	regfn)	\
114 	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print))
115 
116 #undef FTRACE_ENTRY_PACKED
117 #define FTRACE_ENTRY_PACKED(name, struct_name, id, tstruct, print)	\
118 	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print)) __packed
119 
120 #include "trace_entries.h"
121 
122 /* Use this for memory failure errors */
123 #define MEM_FAIL(condition, fmt, ...)					\
124 	DO_ONCE_LITE_IF(condition, pr_err, "ERROR: " fmt, ##__VA_ARGS__)
125 
126 #define FAULT_STRING "(fault)"
127 
128 #define HIST_STACKTRACE_DEPTH	16
129 #define HIST_STACKTRACE_SIZE	(HIST_STACKTRACE_DEPTH * sizeof(unsigned long))
130 #define HIST_STACKTRACE_SKIP	5
131 
132 /*
133  * syscalls are special, and need special handling, this is why
134  * they are not included in trace_entries.h
135  */
136 struct syscall_trace_enter {
137 	struct trace_entry	ent;
138 	int			nr;
139 	unsigned long		args[];
140 };
141 
142 struct syscall_trace_exit {
143 	struct trace_entry	ent;
144 	int			nr;
145 	long			ret;
146 };
147 
148 struct kprobe_trace_entry_head {
149 	struct trace_entry	ent;
150 	unsigned long		ip;
151 };
152 
153 struct eprobe_trace_entry_head {
154 	struct trace_entry	ent;
155 };
156 
157 struct kretprobe_trace_entry_head {
158 	struct trace_entry	ent;
159 	unsigned long		func;
160 	unsigned long		ret_ip;
161 };
162 
163 struct fentry_trace_entry_head {
164 	struct trace_entry	ent;
165 	unsigned long		ip;
166 };
167 
168 struct fexit_trace_entry_head {
169 	struct trace_entry	ent;
170 	unsigned long		func;
171 	unsigned long		ret_ip;
172 };
173 
174 #define TRACE_BUF_SIZE		1024
175 
176 struct trace_array;
177 
178 /*
179  * The CPU trace array - it consists of thousands of trace entries
180  * plus some other descriptor data: (for example which task started
181  * the trace, etc.)
182  */
183 struct trace_array_cpu {
184 	atomic_t		disabled;
185 	void			*buffer_page;	/* ring buffer spare */
186 
187 	unsigned long		entries;
188 	unsigned long		saved_latency;
189 	unsigned long		critical_start;
190 	unsigned long		critical_end;
191 	unsigned long		critical_sequence;
192 	unsigned long		nice;
193 	unsigned long		policy;
194 	unsigned long		rt_priority;
195 	unsigned long		skipped_entries;
196 	u64			preempt_timestamp;
197 	pid_t			pid;
198 	kuid_t			uid;
199 	char			comm[TASK_COMM_LEN];
200 
201 #ifdef CONFIG_FUNCTION_TRACER
202 	int			ftrace_ignore_pid;
203 #endif
204 	bool			ignore_pid;
205 };
206 
207 struct tracer;
208 struct trace_option_dentry;
209 
210 struct array_buffer {
211 	struct trace_array		*tr;
212 	struct trace_buffer		*buffer;
213 	struct trace_array_cpu __percpu	*data;
214 	u64				time_start;
215 	int				cpu;
216 };
217 
218 #define TRACE_FLAGS_MAX_SIZE		32
219 
220 struct trace_options {
221 	struct tracer			*tracer;
222 	struct trace_option_dentry	*topts;
223 };
224 
225 struct trace_pid_list *trace_pid_list_alloc(void);
226 void trace_pid_list_free(struct trace_pid_list *pid_list);
227 bool trace_pid_list_is_set(struct trace_pid_list *pid_list, unsigned int pid);
228 int trace_pid_list_set(struct trace_pid_list *pid_list, unsigned int pid);
229 int trace_pid_list_clear(struct trace_pid_list *pid_list, unsigned int pid);
230 int trace_pid_list_first(struct trace_pid_list *pid_list, unsigned int *pid);
231 int trace_pid_list_next(struct trace_pid_list *pid_list, unsigned int pid,
232 			unsigned int *next);
233 
234 enum {
235 	TRACE_PIDS		= BIT(0),
236 	TRACE_NO_PIDS		= BIT(1),
237 };
238 
239 static inline bool pid_type_enabled(int type, struct trace_pid_list *pid_list,
240 				    struct trace_pid_list *no_pid_list)
241 {
242 	/* Return true if the pid list in type has pids */
243 	return ((type & TRACE_PIDS) && pid_list) ||
244 		((type & TRACE_NO_PIDS) && no_pid_list);
245 }
246 
247 static inline bool still_need_pid_events(int type, struct trace_pid_list *pid_list,
248 					 struct trace_pid_list *no_pid_list)
249 {
250 	/*
251 	 * Turning off what is in @type, return true if the "other"
252 	 * pid list, still has pids in it.
253 	 */
254 	return (!(type & TRACE_PIDS) && pid_list) ||
255 		(!(type & TRACE_NO_PIDS) && no_pid_list);
256 }
257 
258 typedef bool (*cond_update_fn_t)(struct trace_array *tr, void *cond_data);
259 
260 /**
261  * struct cond_snapshot - conditional snapshot data and callback
262  *
263  * The cond_snapshot structure encapsulates a callback function and
264  * data associated with the snapshot for a given tracing instance.
265  *
266  * When a snapshot is taken conditionally, by invoking
267  * tracing_snapshot_cond(tr, cond_data), the cond_data passed in is
268  * passed in turn to the cond_snapshot.update() function.  That data
269  * can be compared by the update() implementation with the cond_data
270  * contained within the struct cond_snapshot instance associated with
271  * the trace_array.  Because the tr->max_lock is held throughout the
272  * update() call, the update() function can directly retrieve the
273  * cond_snapshot and cond_data associated with the per-instance
274  * snapshot associated with the trace_array.
275  *
276  * The cond_snapshot.update() implementation can save data to be
277  * associated with the snapshot if it decides to, and returns 'true'
278  * in that case, or it returns 'false' if the conditional snapshot
279  * shouldn't be taken.
280  *
281  * The cond_snapshot instance is created and associated with the
282  * user-defined cond_data by tracing_cond_snapshot_enable().
283  * Likewise, the cond_snapshot instance is destroyed and is no longer
284  * associated with the trace instance by
285  * tracing_cond_snapshot_disable().
286  *
287  * The method below is required.
288  *
289  * @update: When a conditional snapshot is invoked, the update()
290  *	callback function is invoked with the tr->max_lock held.  The
291  *	update() implementation signals whether or not to actually
292  *	take the snapshot, by returning 'true' if so, 'false' if no
293  *	snapshot should be taken.  Because the max_lock is held for
294  *	the duration of update(), the implementation is safe to
295  *	directly retrieved and save any implementation data it needs
296  *	to in association with the snapshot.
297  */
298 struct cond_snapshot {
299 	void				*cond_data;
300 	cond_update_fn_t		update;
301 };
302 
303 /*
304  * struct trace_func_repeats - used to keep track of the consecutive
305  * (on the same CPU) calls of a single function.
306  */
307 struct trace_func_repeats {
308 	unsigned long	ip;
309 	unsigned long	parent_ip;
310 	unsigned long	count;
311 	u64		ts_last_call;
312 };
313 
314 /*
315  * The trace array - an array of per-CPU trace arrays. This is the
316  * highest level data structure that individual tracers deal with.
317  * They have on/off state as well:
318  */
319 struct trace_array {
320 	struct list_head	list;
321 	char			*name;
322 	struct array_buffer	array_buffer;
323 #ifdef CONFIG_TRACER_MAX_TRACE
324 	/*
325 	 * The max_buffer is used to snapshot the trace when a maximum
326 	 * latency is reached, or when the user initiates a snapshot.
327 	 * Some tracers will use this to store a maximum trace while
328 	 * it continues examining live traces.
329 	 *
330 	 * The buffers for the max_buffer are set up the same as the array_buffer
331 	 * When a snapshot is taken, the buffer of the max_buffer is swapped
332 	 * with the buffer of the array_buffer and the buffers are reset for
333 	 * the array_buffer so the tracing can continue.
334 	 */
335 	struct array_buffer	max_buffer;
336 	bool			allocated_snapshot;
337 	spinlock_t		snapshot_trigger_lock;
338 	unsigned int		snapshot;
339 	unsigned long		max_latency;
340 #ifdef CONFIG_FSNOTIFY
341 	struct dentry		*d_max_latency;
342 	struct work_struct	fsnotify_work;
343 	struct irq_work		fsnotify_irqwork;
344 #endif
345 #endif
346 	/* The below is for memory mapped ring buffer */
347 	unsigned int		mapped;
348 	unsigned long		range_addr_start;
349 	unsigned long		range_addr_size;
350 	long			text_delta;
351 	long			data_delta;
352 
353 	struct trace_pid_list	__rcu *filtered_pids;
354 	struct trace_pid_list	__rcu *filtered_no_pids;
355 	/*
356 	 * max_lock is used to protect the swapping of buffers
357 	 * when taking a max snapshot. The buffers themselves are
358 	 * protected by per_cpu spinlocks. But the action of the swap
359 	 * needs its own lock.
360 	 *
361 	 * This is defined as a arch_spinlock_t in order to help
362 	 * with performance when lockdep debugging is enabled.
363 	 *
364 	 * It is also used in other places outside the update_max_tr
365 	 * so it needs to be defined outside of the
366 	 * CONFIG_TRACER_MAX_TRACE.
367 	 */
368 	arch_spinlock_t		max_lock;
369 	int			buffer_disabled;
370 #ifdef CONFIG_FTRACE_SYSCALLS
371 	int			sys_refcount_enter;
372 	int			sys_refcount_exit;
373 	struct trace_event_file __rcu *enter_syscall_files[NR_syscalls];
374 	struct trace_event_file __rcu *exit_syscall_files[NR_syscalls];
375 #endif
376 	int			stop_count;
377 	int			clock_id;
378 	int			nr_topts;
379 	bool			clear_trace;
380 	int			buffer_percent;
381 	unsigned int		n_err_log_entries;
382 	struct tracer		*current_trace;
383 	unsigned int		trace_flags;
384 	unsigned char		trace_flags_index[TRACE_FLAGS_MAX_SIZE];
385 	unsigned int		flags;
386 	raw_spinlock_t		start_lock;
387 	const char		*system_names;
388 	struct list_head	err_log;
389 	struct dentry		*dir;
390 	struct dentry		*options;
391 	struct dentry		*percpu_dir;
392 	struct eventfs_inode	*event_dir;
393 	struct trace_options	*topts;
394 	struct list_head	systems;
395 	struct list_head	events;
396 	struct trace_event_file *trace_marker_file;
397 	cpumask_var_t		tracing_cpumask; /* only trace on set CPUs */
398 	/* one per_cpu trace_pipe can be opened by only one user */
399 	cpumask_var_t		pipe_cpumask;
400 	int			ref;
401 	int			trace_ref;
402 #ifdef CONFIG_FUNCTION_TRACER
403 	struct ftrace_ops	*ops;
404 	struct trace_pid_list	__rcu *function_pids;
405 	struct trace_pid_list	__rcu *function_no_pids;
406 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
407 	struct fgraph_ops	*gops;
408 #endif
409 #ifdef CONFIG_DYNAMIC_FTRACE
410 	/* All of these are protected by the ftrace_lock */
411 	struct list_head	func_probes;
412 	struct list_head	mod_trace;
413 	struct list_head	mod_notrace;
414 #endif
415 	/* function tracing enabled */
416 	int			function_enabled;
417 #endif
418 	int			no_filter_buffering_ref;
419 	struct list_head	hist_vars;
420 #ifdef CONFIG_TRACER_SNAPSHOT
421 	struct cond_snapshot	*cond_snapshot;
422 #endif
423 	struct trace_func_repeats	__percpu *last_func_repeats;
424 	/*
425 	 * On boot up, the ring buffer is set to the minimum size, so that
426 	 * we do not waste memory on systems that are not using tracing.
427 	 */
428 	bool ring_buffer_expanded;
429 };
430 
431 enum {
432 	TRACE_ARRAY_FL_GLOBAL	= BIT(0),
433 	TRACE_ARRAY_FL_BOOT	= BIT(1),
434 };
435 
436 extern struct list_head ftrace_trace_arrays;
437 
438 extern struct mutex trace_types_lock;
439 
440 extern int trace_array_get(struct trace_array *tr);
441 extern int tracing_check_open_get_tr(struct trace_array *tr);
442 extern struct trace_array *trace_array_find(const char *instance);
443 extern struct trace_array *trace_array_find_get(const char *instance);
444 
445 extern u64 tracing_event_time_stamp(struct trace_buffer *buffer, struct ring_buffer_event *rbe);
446 extern int tracing_set_filter_buffering(struct trace_array *tr, bool set);
447 extern int tracing_set_clock(struct trace_array *tr, const char *clockstr);
448 
449 extern bool trace_clock_in_ns(struct trace_array *tr);
450 
451 /*
452  * The global tracer (top) should be the first trace array added,
453  * but we check the flag anyway.
454  */
455 static inline struct trace_array *top_trace_array(void)
456 {
457 	struct trace_array *tr;
458 
459 	if (list_empty(&ftrace_trace_arrays))
460 		return NULL;
461 
462 	tr = list_entry(ftrace_trace_arrays.prev,
463 			typeof(*tr), list);
464 	WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
465 	return tr;
466 }
467 
468 #define FTRACE_CMP_TYPE(var, type) \
469 	__builtin_types_compatible_p(typeof(var), type *)
470 
471 #undef IF_ASSIGN
472 #define IF_ASSIGN(var, entry, etype, id)			\
473 	if (FTRACE_CMP_TYPE(var, etype)) {			\
474 		var = (typeof(var))(entry);			\
475 		WARN_ON(id != 0 && (entry)->type != id);	\
476 		break;						\
477 	}
478 
479 /* Will cause compile errors if type is not found. */
480 extern void __ftrace_bad_type(void);
481 
482 /*
483  * The trace_assign_type is a verifier that the entry type is
484  * the same as the type being assigned. To add new types simply
485  * add a line with the following format:
486  *
487  * IF_ASSIGN(var, ent, type, id);
488  *
489  *  Where "type" is the trace type that includes the trace_entry
490  *  as the "ent" item. And "id" is the trace identifier that is
491  *  used in the trace_type enum.
492  *
493  *  If the type can have more than one id, then use zero.
494  */
495 #define trace_assign_type(var, ent)					\
496 	do {								\
497 		IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);	\
498 		IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);	\
499 		IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);	\
500 		IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
501 		IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);	\
502 		IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT);	\
503 		IF_ASSIGN(var, ent, struct bputs_entry, TRACE_BPUTS);	\
504 		IF_ASSIGN(var, ent, struct hwlat_entry, TRACE_HWLAT);	\
505 		IF_ASSIGN(var, ent, struct osnoise_entry, TRACE_OSNOISE);\
506 		IF_ASSIGN(var, ent, struct timerlat_entry, TRACE_TIMERLAT);\
507 		IF_ASSIGN(var, ent, struct raw_data_entry, TRACE_RAW_DATA);\
508 		IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,		\
509 			  TRACE_MMIO_RW);				\
510 		IF_ASSIGN(var, ent, struct trace_mmiotrace_map,		\
511 			  TRACE_MMIO_MAP);				\
512 		IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
513 		IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,	\
514 			  TRACE_GRAPH_ENT);		\
515 		IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,	\
516 			  TRACE_GRAPH_RET);		\
517 		IF_ASSIGN(var, ent, struct func_repeats_entry,		\
518 			  TRACE_FUNC_REPEATS);				\
519 		__ftrace_bad_type();					\
520 	} while (0)
521 
522 /*
523  * An option specific to a tracer. This is a boolean value.
524  * The bit is the bit index that sets its value on the
525  * flags value in struct tracer_flags.
526  */
527 struct tracer_opt {
528 	const char	*name; /* Will appear on the trace_options file */
529 	u32		bit; /* Mask assigned in val field in tracer_flags */
530 };
531 
532 /*
533  * The set of specific options for a tracer. Your tracer
534  * have to set the initial value of the flags val.
535  */
536 struct tracer_flags {
537 	u32			val;
538 	struct tracer_opt	*opts;
539 	struct tracer		*trace;
540 };
541 
542 /* Makes more easy to define a tracer opt */
543 #define TRACER_OPT(s, b)	.name = #s, .bit = b
544 
545 
546 struct trace_option_dentry {
547 	struct tracer_opt		*opt;
548 	struct tracer_flags		*flags;
549 	struct trace_array		*tr;
550 	struct dentry			*entry;
551 };
552 
553 /**
554  * struct tracer - a specific tracer and its callbacks to interact with tracefs
555  * @name: the name chosen to select it on the available_tracers file
556  * @init: called when one switches to this tracer (echo name > current_tracer)
557  * @reset: called when one switches to another tracer
558  * @start: called when tracing is unpaused (echo 1 > tracing_on)
559  * @stop: called when tracing is paused (echo 0 > tracing_on)
560  * @update_thresh: called when tracing_thresh is updated
561  * @open: called when the trace file is opened
562  * @pipe_open: called when the trace_pipe file is opened
563  * @close: called when the trace file is released
564  * @pipe_close: called when the trace_pipe file is released
565  * @read: override the default read callback on trace_pipe
566  * @splice_read: override the default splice_read callback on trace_pipe
567  * @selftest: selftest to run on boot (see trace_selftest.c)
568  * @print_headers: override the first lines that describe your columns
569  * @print_line: callback that prints a trace
570  * @set_flag: signals one of your private flags changed (trace_options file)
571  * @flags: your private flags
572  */
573 struct tracer {
574 	const char		*name;
575 	int			(*init)(struct trace_array *tr);
576 	void			(*reset)(struct trace_array *tr);
577 	void			(*start)(struct trace_array *tr);
578 	void			(*stop)(struct trace_array *tr);
579 	int			(*update_thresh)(struct trace_array *tr);
580 	void			(*open)(struct trace_iterator *iter);
581 	void			(*pipe_open)(struct trace_iterator *iter);
582 	void			(*close)(struct trace_iterator *iter);
583 	void			(*pipe_close)(struct trace_iterator *iter);
584 	ssize_t			(*read)(struct trace_iterator *iter,
585 					struct file *filp, char __user *ubuf,
586 					size_t cnt, loff_t *ppos);
587 	ssize_t			(*splice_read)(struct trace_iterator *iter,
588 					       struct file *filp,
589 					       loff_t *ppos,
590 					       struct pipe_inode_info *pipe,
591 					       size_t len,
592 					       unsigned int flags);
593 #ifdef CONFIG_FTRACE_STARTUP_TEST
594 	int			(*selftest)(struct tracer *trace,
595 					    struct trace_array *tr);
596 #endif
597 	void			(*print_header)(struct seq_file *m);
598 	enum print_line_t	(*print_line)(struct trace_iterator *iter);
599 	/* If you handled the flag setting, return 0 */
600 	int			(*set_flag)(struct trace_array *tr,
601 					    u32 old_flags, u32 bit, int set);
602 	/* Return 0 if OK with change, else return non-zero */
603 	int			(*flag_changed)(struct trace_array *tr,
604 						u32 mask, int set);
605 	struct tracer		*next;
606 	struct tracer_flags	*flags;
607 	int			enabled;
608 	bool			print_max;
609 	bool			allow_instances;
610 #ifdef CONFIG_TRACER_MAX_TRACE
611 	bool			use_max_tr;
612 #endif
613 	/* True if tracer cannot be enabled in kernel param */
614 	bool			noboot;
615 };
616 
617 static inline struct ring_buffer_iter *
618 trace_buffer_iter(struct trace_iterator *iter, int cpu)
619 {
620 	return iter->buffer_iter ? iter->buffer_iter[cpu] : NULL;
621 }
622 
623 int tracer_init(struct tracer *t, struct trace_array *tr);
624 int tracing_is_enabled(void);
625 void tracing_reset_online_cpus(struct array_buffer *buf);
626 void tracing_reset_all_online_cpus(void);
627 void tracing_reset_all_online_cpus_unlocked(void);
628 int tracing_open_generic(struct inode *inode, struct file *filp);
629 int tracing_open_generic_tr(struct inode *inode, struct file *filp);
630 int tracing_release_generic_tr(struct inode *inode, struct file *file);
631 int tracing_open_file_tr(struct inode *inode, struct file *filp);
632 int tracing_release_file_tr(struct inode *inode, struct file *filp);
633 int tracing_single_release_file_tr(struct inode *inode, struct file *filp);
634 bool tracing_is_disabled(void);
635 bool tracer_tracing_is_on(struct trace_array *tr);
636 void tracer_tracing_on(struct trace_array *tr);
637 void tracer_tracing_off(struct trace_array *tr);
638 struct dentry *trace_create_file(const char *name,
639 				 umode_t mode,
640 				 struct dentry *parent,
641 				 void *data,
642 				 const struct file_operations *fops);
643 
644 int tracing_init_dentry(void);
645 
646 struct ring_buffer_event;
647 
648 struct ring_buffer_event *
649 trace_buffer_lock_reserve(struct trace_buffer *buffer,
650 			  int type,
651 			  unsigned long len,
652 			  unsigned int trace_ctx);
653 
654 int ring_buffer_meta_seq_init(struct file *file, struct trace_buffer *buffer, int cpu);
655 
656 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
657 						struct trace_array_cpu *data);
658 
659 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
660 					  int *ent_cpu, u64 *ent_ts);
661 
662 void trace_buffer_unlock_commit_nostack(struct trace_buffer *buffer,
663 					struct ring_buffer_event *event);
664 
665 bool trace_is_tracepoint_string(const char *str);
666 const char *trace_event_format(struct trace_iterator *iter, const char *fmt);
667 void trace_check_vprintf(struct trace_iterator *iter, const char *fmt,
668 			 va_list ap) __printf(2, 0);
669 char *trace_iter_expand_format(struct trace_iterator *iter);
670 
671 int trace_empty(struct trace_iterator *iter);
672 
673 void *trace_find_next_entry_inc(struct trace_iterator *iter);
674 
675 void trace_init_global_iter(struct trace_iterator *iter);
676 
677 void tracing_iter_reset(struct trace_iterator *iter, int cpu);
678 
679 unsigned long trace_total_entries_cpu(struct trace_array *tr, int cpu);
680 unsigned long trace_total_entries(struct trace_array *tr);
681 
682 void trace_function(struct trace_array *tr,
683 		    unsigned long ip,
684 		    unsigned long parent_ip,
685 		    unsigned int trace_ctx);
686 void trace_graph_function(struct trace_array *tr,
687 		    unsigned long ip,
688 		    unsigned long parent_ip,
689 		    unsigned int trace_ctx);
690 void trace_latency_header(struct seq_file *m);
691 void trace_default_header(struct seq_file *m);
692 void print_trace_header(struct seq_file *m, struct trace_iterator *iter);
693 
694 void trace_graph_return(struct ftrace_graph_ret *trace, struct fgraph_ops *gops);
695 int trace_graph_entry(struct ftrace_graph_ent *trace, struct fgraph_ops *gops);
696 
697 void tracing_start_cmdline_record(void);
698 void tracing_stop_cmdline_record(void);
699 void tracing_start_tgid_record(void);
700 void tracing_stop_tgid_record(void);
701 
702 int register_tracer(struct tracer *type);
703 int is_tracing_stopped(void);
704 
705 loff_t tracing_lseek(struct file *file, loff_t offset, int whence);
706 
707 extern cpumask_var_t __read_mostly tracing_buffer_mask;
708 
709 #define for_each_tracing_cpu(cpu)	\
710 	for_each_cpu(cpu, tracing_buffer_mask)
711 
712 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
713 
714 extern unsigned long tracing_thresh;
715 
716 /* PID filtering */
717 
718 extern int pid_max;
719 
720 bool trace_find_filtered_pid(struct trace_pid_list *filtered_pids,
721 			     pid_t search_pid);
722 bool trace_ignore_this_task(struct trace_pid_list *filtered_pids,
723 			    struct trace_pid_list *filtered_no_pids,
724 			    struct task_struct *task);
725 void trace_filter_add_remove_task(struct trace_pid_list *pid_list,
726 				  struct task_struct *self,
727 				  struct task_struct *task);
728 void *trace_pid_next(struct trace_pid_list *pid_list, void *v, loff_t *pos);
729 void *trace_pid_start(struct trace_pid_list *pid_list, loff_t *pos);
730 int trace_pid_show(struct seq_file *m, void *v);
731 int trace_pid_write(struct trace_pid_list *filtered_pids,
732 		    struct trace_pid_list **new_pid_list,
733 		    const char __user *ubuf, size_t cnt);
734 
735 #ifdef CONFIG_TRACER_MAX_TRACE
736 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu,
737 		   void *cond_data);
738 void update_max_tr_single(struct trace_array *tr,
739 			  struct task_struct *tsk, int cpu);
740 
741 #ifdef CONFIG_FSNOTIFY
742 #define LATENCY_FS_NOTIFY
743 #endif
744 #endif /* CONFIG_TRACER_MAX_TRACE */
745 
746 #ifdef LATENCY_FS_NOTIFY
747 void latency_fsnotify(struct trace_array *tr);
748 #else
749 static inline void latency_fsnotify(struct trace_array *tr) { }
750 #endif
751 
752 #ifdef CONFIG_STACKTRACE
753 void __trace_stack(struct trace_array *tr, unsigned int trace_ctx, int skip);
754 #else
755 static inline void __trace_stack(struct trace_array *tr, unsigned int trace_ctx,
756 				 int skip)
757 {
758 }
759 #endif /* CONFIG_STACKTRACE */
760 
761 void trace_last_func_repeats(struct trace_array *tr,
762 			     struct trace_func_repeats *last_info,
763 			     unsigned int trace_ctx);
764 
765 extern u64 ftrace_now(int cpu);
766 
767 extern void trace_find_cmdline(int pid, char comm[]);
768 extern int trace_find_tgid(int pid);
769 extern void trace_event_follow_fork(struct trace_array *tr, bool enable);
770 
771 #ifdef CONFIG_DYNAMIC_FTRACE
772 extern unsigned long ftrace_update_tot_cnt;
773 extern unsigned long ftrace_number_of_pages;
774 extern unsigned long ftrace_number_of_groups;
775 void ftrace_init_trace_array(struct trace_array *tr);
776 #else
777 static inline void ftrace_init_trace_array(struct trace_array *tr) { }
778 #endif
779 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
780 extern int DYN_FTRACE_TEST_NAME(void);
781 #define DYN_FTRACE_TEST_NAME2 trace_selftest_dynamic_test_func2
782 extern int DYN_FTRACE_TEST_NAME2(void);
783 
784 extern void trace_set_ring_buffer_expanded(struct trace_array *tr);
785 extern bool tracing_selftest_disabled;
786 
787 #ifdef CONFIG_FTRACE_STARTUP_TEST
788 extern void __init disable_tracing_selftest(const char *reason);
789 
790 extern int trace_selftest_startup_function(struct tracer *trace,
791 					   struct trace_array *tr);
792 extern int trace_selftest_startup_function_graph(struct tracer *trace,
793 						 struct trace_array *tr);
794 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
795 					  struct trace_array *tr);
796 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
797 					     struct trace_array *tr);
798 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
799 						 struct trace_array *tr);
800 extern int trace_selftest_startup_wakeup(struct tracer *trace,
801 					 struct trace_array *tr);
802 extern int trace_selftest_startup_nop(struct tracer *trace,
803 					 struct trace_array *tr);
804 extern int trace_selftest_startup_branch(struct tracer *trace,
805 					 struct trace_array *tr);
806 /*
807  * Tracer data references selftest functions that only occur
808  * on boot up. These can be __init functions. Thus, when selftests
809  * are enabled, then the tracers need to reference __init functions.
810  */
811 #define __tracer_data		__refdata
812 #else
813 static inline void __init disable_tracing_selftest(const char *reason)
814 {
815 }
816 /* Tracers are seldom changed. Optimize when selftests are disabled. */
817 #define __tracer_data		__read_mostly
818 #endif /* CONFIG_FTRACE_STARTUP_TEST */
819 
820 extern void *head_page(struct trace_array_cpu *data);
821 extern unsigned long long ns2usecs(u64 nsec);
822 extern int
823 trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
824 extern int
825 trace_vprintk(unsigned long ip, const char *fmt, va_list args);
826 extern int
827 trace_array_vprintk(struct trace_array *tr,
828 		    unsigned long ip, const char *fmt, va_list args);
829 int trace_array_printk_buf(struct trace_buffer *buffer,
830 			   unsigned long ip, const char *fmt, ...);
831 void trace_printk_seq(struct trace_seq *s);
832 enum print_line_t print_trace_line(struct trace_iterator *iter);
833 
834 extern char trace_find_mark(unsigned long long duration);
835 
836 struct ftrace_hash;
837 
838 struct ftrace_mod_load {
839 	struct list_head	list;
840 	char			*func;
841 	char			*module;
842 	int			 enable;
843 };
844 
845 enum {
846 	FTRACE_HASH_FL_MOD	= (1 << 0),
847 };
848 
849 struct ftrace_hash {
850 	unsigned long		size_bits;
851 	struct hlist_head	*buckets;
852 	unsigned long		count;
853 	unsigned long		flags;
854 	struct rcu_head		rcu;
855 };
856 
857 struct ftrace_func_entry *
858 ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip);
859 
860 static __always_inline bool ftrace_hash_empty(struct ftrace_hash *hash)
861 {
862 	return !hash || !(hash->count || (hash->flags & FTRACE_HASH_FL_MOD));
863 }
864 
865 /* Standard output formatting function used for function return traces */
866 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
867 
868 /* Flag options */
869 #define TRACE_GRAPH_PRINT_OVERRUN       0x1
870 #define TRACE_GRAPH_PRINT_CPU           0x2
871 #define TRACE_GRAPH_PRINT_OVERHEAD      0x4
872 #define TRACE_GRAPH_PRINT_PROC          0x8
873 #define TRACE_GRAPH_PRINT_DURATION      0x10
874 #define TRACE_GRAPH_PRINT_ABS_TIME      0x20
875 #define TRACE_GRAPH_PRINT_REL_TIME      0x40
876 #define TRACE_GRAPH_PRINT_IRQS          0x80
877 #define TRACE_GRAPH_PRINT_TAIL          0x100
878 #define TRACE_GRAPH_SLEEP_TIME          0x200
879 #define TRACE_GRAPH_GRAPH_TIME          0x400
880 #define TRACE_GRAPH_PRINT_RETVAL        0x800
881 #define TRACE_GRAPH_PRINT_RETVAL_HEX    0x1000
882 #define TRACE_GRAPH_PRINT_FILL_SHIFT	28
883 #define TRACE_GRAPH_PRINT_FILL_MASK	(0x3 << TRACE_GRAPH_PRINT_FILL_SHIFT)
884 
885 extern void ftrace_graph_sleep_time_control(bool enable);
886 
887 #ifdef CONFIG_FUNCTION_PROFILER
888 extern void ftrace_graph_graph_time_control(bool enable);
889 #else
890 static inline void ftrace_graph_graph_time_control(bool enable) { }
891 #endif
892 
893 extern enum print_line_t
894 print_graph_function_flags(struct trace_iterator *iter, u32 flags);
895 extern void print_graph_headers_flags(struct seq_file *s, u32 flags);
896 extern void
897 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
898 extern void graph_trace_open(struct trace_iterator *iter);
899 extern void graph_trace_close(struct trace_iterator *iter);
900 extern int __trace_graph_entry(struct trace_array *tr,
901 			       struct ftrace_graph_ent *trace,
902 			       unsigned int trace_ctx);
903 extern void __trace_graph_return(struct trace_array *tr,
904 				 struct ftrace_graph_ret *trace,
905 				 unsigned int trace_ctx);
906 extern void init_array_fgraph_ops(struct trace_array *tr, struct ftrace_ops *ops);
907 extern int allocate_fgraph_ops(struct trace_array *tr, struct ftrace_ops *ops);
908 extern void free_fgraph_ops(struct trace_array *tr);
909 
910 enum {
911 	TRACE_GRAPH_FL		= 1,
912 
913 	/*
914 	 * In the very unlikely case that an interrupt came in
915 	 * at a start of graph tracing, and we want to trace
916 	 * the function in that interrupt, the depth can be greater
917 	 * than zero, because of the preempted start of a previous
918 	 * trace. In an even more unlikely case, depth could be 2
919 	 * if a softirq interrupted the start of graph tracing,
920 	 * followed by an interrupt preempting a start of graph
921 	 * tracing in the softirq, and depth can even be 3
922 	 * if an NMI came in at the start of an interrupt function
923 	 * that preempted a softirq start of a function that
924 	 * preempted normal context!!!! Luckily, it can't be
925 	 * greater than 3, so the next two bits are a mask
926 	 * of what the depth is when we set TRACE_GRAPH_FL
927 	 */
928 
929 	TRACE_GRAPH_DEPTH_START_BIT,
930 	TRACE_GRAPH_DEPTH_END_BIT,
931 
932 	/*
933 	 * To implement set_graph_notrace, if this bit is set, we ignore
934 	 * function graph tracing of called functions, until the return
935 	 * function is called to clear it.
936 	 */
937 	TRACE_GRAPH_NOTRACE_BIT,
938 };
939 
940 #define TRACE_GRAPH_NOTRACE		(1 << TRACE_GRAPH_NOTRACE_BIT)
941 
942 static inline unsigned long ftrace_graph_depth(unsigned long *task_var)
943 {
944 	return (*task_var >> TRACE_GRAPH_DEPTH_START_BIT) & 3;
945 }
946 
947 static inline void ftrace_graph_set_depth(unsigned long *task_var, int depth)
948 {
949 	*task_var &= ~(3 << TRACE_GRAPH_DEPTH_START_BIT);
950 	*task_var |= (depth & 3) << TRACE_GRAPH_DEPTH_START_BIT;
951 }
952 
953 #ifdef CONFIG_DYNAMIC_FTRACE
954 extern struct ftrace_hash __rcu *ftrace_graph_hash;
955 extern struct ftrace_hash __rcu *ftrace_graph_notrace_hash;
956 
957 static inline int
958 ftrace_graph_addr(unsigned long *task_var, struct ftrace_graph_ent *trace)
959 {
960 	unsigned long addr = trace->func;
961 	int ret = 0;
962 	struct ftrace_hash *hash;
963 
964 	preempt_disable_notrace();
965 
966 	/*
967 	 * Have to open code "rcu_dereference_sched()" because the
968 	 * function graph tracer can be called when RCU is not
969 	 * "watching".
970 	 * Protected with schedule_on_each_cpu(ftrace_sync)
971 	 */
972 	hash = rcu_dereference_protected(ftrace_graph_hash, !preemptible());
973 
974 	if (ftrace_hash_empty(hash)) {
975 		ret = 1;
976 		goto out;
977 	}
978 
979 	if (ftrace_lookup_ip(hash, addr)) {
980 		/*
981 		 * This needs to be cleared on the return functions
982 		 * when the depth is zero.
983 		 */
984 		*task_var |= TRACE_GRAPH_FL;
985 		ftrace_graph_set_depth(task_var, trace->depth);
986 
987 		/*
988 		 * If no irqs are to be traced, but a set_graph_function
989 		 * is set, and called by an interrupt handler, we still
990 		 * want to trace it.
991 		 */
992 		if (in_hardirq())
993 			trace_recursion_set(TRACE_IRQ_BIT);
994 		else
995 			trace_recursion_clear(TRACE_IRQ_BIT);
996 		ret = 1;
997 	}
998 
999 out:
1000 	preempt_enable_notrace();
1001 	return ret;
1002 }
1003 
1004 static inline void
1005 ftrace_graph_addr_finish(struct fgraph_ops *gops, struct ftrace_graph_ret *trace)
1006 {
1007 	unsigned long *task_var = fgraph_get_task_var(gops);
1008 
1009 	if ((*task_var & TRACE_GRAPH_FL) &&
1010 	    trace->depth == ftrace_graph_depth(task_var))
1011 		*task_var &= ~TRACE_GRAPH_FL;
1012 }
1013 
1014 static inline int ftrace_graph_notrace_addr(unsigned long addr)
1015 {
1016 	int ret = 0;
1017 	struct ftrace_hash *notrace_hash;
1018 
1019 	preempt_disable_notrace();
1020 
1021 	/*
1022 	 * Have to open code "rcu_dereference_sched()" because the
1023 	 * function graph tracer can be called when RCU is not
1024 	 * "watching".
1025 	 * Protected with schedule_on_each_cpu(ftrace_sync)
1026 	 */
1027 	notrace_hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
1028 						 !preemptible());
1029 
1030 	if (ftrace_lookup_ip(notrace_hash, addr))
1031 		ret = 1;
1032 
1033 	preempt_enable_notrace();
1034 	return ret;
1035 }
1036 #else
1037 static inline int ftrace_graph_addr(unsigned long *task_var, struct ftrace_graph_ent *trace)
1038 {
1039 	return 1;
1040 }
1041 
1042 static inline int ftrace_graph_notrace_addr(unsigned long addr)
1043 {
1044 	return 0;
1045 }
1046 static inline void ftrace_graph_addr_finish(struct fgraph_ops *gops, struct ftrace_graph_ret *trace)
1047 { }
1048 #endif /* CONFIG_DYNAMIC_FTRACE */
1049 
1050 extern unsigned int fgraph_max_depth;
1051 
1052 static inline bool
1053 ftrace_graph_ignore_func(struct fgraph_ops *gops, struct ftrace_graph_ent *trace)
1054 {
1055 	unsigned long *task_var = fgraph_get_task_var(gops);
1056 
1057 	/* trace it when it is-nested-in or is a function enabled. */
1058 	return !((*task_var & TRACE_GRAPH_FL) ||
1059 		 ftrace_graph_addr(task_var, trace)) ||
1060 		(trace->depth < 0) ||
1061 		(fgraph_max_depth && trace->depth >= fgraph_max_depth);
1062 }
1063 
1064 void fgraph_init_ops(struct ftrace_ops *dst_ops,
1065 		     struct ftrace_ops *src_ops);
1066 
1067 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
1068 static inline enum print_line_t
1069 print_graph_function_flags(struct trace_iterator *iter, u32 flags)
1070 {
1071 	return TRACE_TYPE_UNHANDLED;
1072 }
1073 static inline void free_fgraph_ops(struct trace_array *tr) { }
1074 /* ftrace_ops may not be defined */
1075 #define init_array_fgraph_ops(tr, ops) do { } while (0)
1076 #define allocate_fgraph_ops(tr, ops) ({ 0; })
1077 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
1078 
1079 extern struct list_head ftrace_pids;
1080 
1081 #ifdef CONFIG_FUNCTION_TRACER
1082 
1083 #define FTRACE_PID_IGNORE	-1
1084 #define FTRACE_PID_TRACE	-2
1085 
1086 struct ftrace_func_command {
1087 	struct list_head	list;
1088 	char			*name;
1089 	int			(*func)(struct trace_array *tr,
1090 					struct ftrace_hash *hash,
1091 					char *func, char *cmd,
1092 					char *params, int enable);
1093 };
1094 extern bool ftrace_filter_param __initdata;
1095 static inline int ftrace_trace_task(struct trace_array *tr)
1096 {
1097 	return this_cpu_read(tr->array_buffer.data->ftrace_ignore_pid) !=
1098 		FTRACE_PID_IGNORE;
1099 }
1100 extern int ftrace_is_dead(void);
1101 int ftrace_create_function_files(struct trace_array *tr,
1102 				 struct dentry *parent);
1103 void ftrace_destroy_function_files(struct trace_array *tr);
1104 int ftrace_allocate_ftrace_ops(struct trace_array *tr);
1105 void ftrace_free_ftrace_ops(struct trace_array *tr);
1106 void ftrace_init_global_array_ops(struct trace_array *tr);
1107 void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func);
1108 void ftrace_reset_array_ops(struct trace_array *tr);
1109 void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer);
1110 void ftrace_init_tracefs_toplevel(struct trace_array *tr,
1111 				  struct dentry *d_tracer);
1112 void ftrace_clear_pids(struct trace_array *tr);
1113 int init_function_trace(void);
1114 void ftrace_pid_follow_fork(struct trace_array *tr, bool enable);
1115 #else
1116 static inline int ftrace_trace_task(struct trace_array *tr)
1117 {
1118 	return 1;
1119 }
1120 static inline int ftrace_is_dead(void) { return 0; }
1121 static inline int
1122 ftrace_create_function_files(struct trace_array *tr,
1123 			     struct dentry *parent)
1124 {
1125 	return 0;
1126 }
1127 static inline int ftrace_allocate_ftrace_ops(struct trace_array *tr)
1128 {
1129 	return 0;
1130 }
1131 static inline void ftrace_free_ftrace_ops(struct trace_array *tr) { }
1132 static inline void ftrace_destroy_function_files(struct trace_array *tr) { }
1133 static inline __init void
1134 ftrace_init_global_array_ops(struct trace_array *tr) { }
1135 static inline void ftrace_reset_array_ops(struct trace_array *tr) { }
1136 static inline void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d) { }
1137 static inline void ftrace_init_tracefs_toplevel(struct trace_array *tr, struct dentry *d) { }
1138 static inline void ftrace_clear_pids(struct trace_array *tr) { }
1139 static inline int init_function_trace(void) { return 0; }
1140 static inline void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) { }
1141 /* ftace_func_t type is not defined, use macro instead of static inline */
1142 #define ftrace_init_array_ops(tr, func) do { } while (0)
1143 #endif /* CONFIG_FUNCTION_TRACER */
1144 
1145 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
1146 
1147 struct ftrace_probe_ops {
1148 	void			(*func)(unsigned long ip,
1149 					unsigned long parent_ip,
1150 					struct trace_array *tr,
1151 					struct ftrace_probe_ops *ops,
1152 					void *data);
1153 	int			(*init)(struct ftrace_probe_ops *ops,
1154 					struct trace_array *tr,
1155 					unsigned long ip, void *init_data,
1156 					void **data);
1157 	void			(*free)(struct ftrace_probe_ops *ops,
1158 					struct trace_array *tr,
1159 					unsigned long ip, void *data);
1160 	int			(*print)(struct seq_file *m,
1161 					 unsigned long ip,
1162 					 struct ftrace_probe_ops *ops,
1163 					 void *data);
1164 };
1165 
1166 struct ftrace_func_mapper;
1167 typedef int (*ftrace_mapper_func)(void *data);
1168 
1169 struct ftrace_func_mapper *allocate_ftrace_func_mapper(void);
1170 void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
1171 					   unsigned long ip);
1172 int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
1173 			       unsigned long ip, void *data);
1174 void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
1175 				   unsigned long ip);
1176 void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
1177 			     ftrace_mapper_func free_func);
1178 
1179 extern int
1180 register_ftrace_function_probe(char *glob, struct trace_array *tr,
1181 			       struct ftrace_probe_ops *ops, void *data);
1182 extern int
1183 unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
1184 				      struct ftrace_probe_ops *ops);
1185 extern void clear_ftrace_function_probes(struct trace_array *tr);
1186 
1187 int register_ftrace_command(struct ftrace_func_command *cmd);
1188 int unregister_ftrace_command(struct ftrace_func_command *cmd);
1189 
1190 void ftrace_create_filter_files(struct ftrace_ops *ops,
1191 				struct dentry *parent);
1192 void ftrace_destroy_filter_files(struct ftrace_ops *ops);
1193 
1194 extern int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
1195 			     int len, int reset);
1196 extern int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
1197 			      int len, int reset);
1198 #else
1199 struct ftrace_func_command;
1200 
1201 static inline __init int register_ftrace_command(struct ftrace_func_command *cmd)
1202 {
1203 	return -EINVAL;
1204 }
1205 static inline __init int unregister_ftrace_command(char *cmd_name)
1206 {
1207 	return -EINVAL;
1208 }
1209 static inline void clear_ftrace_function_probes(struct trace_array *tr)
1210 {
1211 }
1212 
1213 /*
1214  * The ops parameter passed in is usually undefined.
1215  * This must be a macro.
1216  */
1217 #define ftrace_create_filter_files(ops, parent) do { } while (0)
1218 #define ftrace_destroy_filter_files(ops) do { } while (0)
1219 #endif /* CONFIG_FUNCTION_TRACER && CONFIG_DYNAMIC_FTRACE */
1220 
1221 bool ftrace_event_is_function(struct trace_event_call *call);
1222 
1223 /*
1224  * struct trace_parser - servers for reading the user input separated by spaces
1225  * @cont: set if the input is not complete - no final space char was found
1226  * @buffer: holds the parsed user input
1227  * @idx: user input length
1228  * @size: buffer size
1229  */
1230 struct trace_parser {
1231 	bool		cont;
1232 	char		*buffer;
1233 	unsigned	idx;
1234 	unsigned	size;
1235 };
1236 
1237 static inline bool trace_parser_loaded(struct trace_parser *parser)
1238 {
1239 	return (parser->idx != 0);
1240 }
1241 
1242 static inline bool trace_parser_cont(struct trace_parser *parser)
1243 {
1244 	return parser->cont;
1245 }
1246 
1247 static inline void trace_parser_clear(struct trace_parser *parser)
1248 {
1249 	parser->cont = false;
1250 	parser->idx = 0;
1251 }
1252 
1253 extern int trace_parser_get_init(struct trace_parser *parser, int size);
1254 extern void trace_parser_put(struct trace_parser *parser);
1255 extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
1256 	size_t cnt, loff_t *ppos);
1257 
1258 /*
1259  * Only create function graph options if function graph is configured.
1260  */
1261 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1262 # define FGRAPH_FLAGS						\
1263 		C(DISPLAY_GRAPH,	"display-graph"),
1264 #else
1265 # define FGRAPH_FLAGS
1266 #endif
1267 
1268 #ifdef CONFIG_BRANCH_TRACER
1269 # define BRANCH_FLAGS					\
1270 		C(BRANCH,		"branch"),
1271 #else
1272 # define BRANCH_FLAGS
1273 #endif
1274 
1275 #ifdef CONFIG_FUNCTION_TRACER
1276 # define FUNCTION_FLAGS						\
1277 		C(FUNCTION,		"function-trace"),	\
1278 		C(FUNC_FORK,		"function-fork"),
1279 # define FUNCTION_DEFAULT_FLAGS		TRACE_ITER_FUNCTION
1280 #else
1281 # define FUNCTION_FLAGS
1282 # define FUNCTION_DEFAULT_FLAGS		0UL
1283 # define TRACE_ITER_FUNC_FORK		0UL
1284 #endif
1285 
1286 #ifdef CONFIG_STACKTRACE
1287 # define STACK_FLAGS				\
1288 		C(STACKTRACE,		"stacktrace"),
1289 #else
1290 # define STACK_FLAGS
1291 #endif
1292 
1293 /*
1294  * trace_iterator_flags is an enumeration that defines bit
1295  * positions into trace_flags that controls the output.
1296  *
1297  * NOTE: These bits must match the trace_options array in
1298  *       trace.c (this macro guarantees it).
1299  */
1300 #define TRACE_FLAGS						\
1301 		C(PRINT_PARENT,		"print-parent"),	\
1302 		C(SYM_OFFSET,		"sym-offset"),		\
1303 		C(SYM_ADDR,		"sym-addr"),		\
1304 		C(VERBOSE,		"verbose"),		\
1305 		C(RAW,			"raw"),			\
1306 		C(HEX,			"hex"),			\
1307 		C(BIN,			"bin"),			\
1308 		C(BLOCK,		"block"),		\
1309 		C(FIELDS,		"fields"),		\
1310 		C(PRINTK,		"trace_printk"),	\
1311 		C(ANNOTATE,		"annotate"),		\
1312 		C(USERSTACKTRACE,	"userstacktrace"),	\
1313 		C(SYM_USEROBJ,		"sym-userobj"),		\
1314 		C(PRINTK_MSGONLY,	"printk-msg-only"),	\
1315 		C(CONTEXT_INFO,		"context-info"),   /* Print pid/cpu/time */ \
1316 		C(LATENCY_FMT,		"latency-format"),	\
1317 		C(RECORD_CMD,		"record-cmd"),		\
1318 		C(RECORD_TGID,		"record-tgid"),		\
1319 		C(OVERWRITE,		"overwrite"),		\
1320 		C(STOP_ON_FREE,		"disable_on_free"),	\
1321 		C(IRQ_INFO,		"irq-info"),		\
1322 		C(MARKERS,		"markers"),		\
1323 		C(EVENT_FORK,		"event-fork"),		\
1324 		C(TRACE_PRINTK,		"trace_printk_dest"),	\
1325 		C(PAUSE_ON_TRACE,	"pause-on-trace"),	\
1326 		C(HASH_PTR,		"hash-ptr"),	/* Print hashed pointer */ \
1327 		FUNCTION_FLAGS					\
1328 		FGRAPH_FLAGS					\
1329 		STACK_FLAGS					\
1330 		BRANCH_FLAGS
1331 
1332 /*
1333  * By defining C, we can make TRACE_FLAGS a list of bit names
1334  * that will define the bits for the flag masks.
1335  */
1336 #undef C
1337 #define C(a, b) TRACE_ITER_##a##_BIT
1338 
1339 enum trace_iterator_bits {
1340 	TRACE_FLAGS
1341 	/* Make sure we don't go more than we have bits for */
1342 	TRACE_ITER_LAST_BIT
1343 };
1344 
1345 /*
1346  * By redefining C, we can make TRACE_FLAGS a list of masks that
1347  * use the bits as defined above.
1348  */
1349 #undef C
1350 #define C(a, b) TRACE_ITER_##a = (1 << TRACE_ITER_##a##_BIT)
1351 
1352 enum trace_iterator_flags { TRACE_FLAGS };
1353 
1354 /*
1355  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
1356  * control the output of kernel symbols.
1357  */
1358 #define TRACE_ITER_SYM_MASK \
1359 	(TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
1360 
1361 extern struct tracer nop_trace;
1362 
1363 #ifdef CONFIG_BRANCH_TRACER
1364 extern int enable_branch_tracing(struct trace_array *tr);
1365 extern void disable_branch_tracing(void);
1366 static inline int trace_branch_enable(struct trace_array *tr)
1367 {
1368 	if (tr->trace_flags & TRACE_ITER_BRANCH)
1369 		return enable_branch_tracing(tr);
1370 	return 0;
1371 }
1372 static inline void trace_branch_disable(void)
1373 {
1374 	/* due to races, always disable */
1375 	disable_branch_tracing();
1376 }
1377 #else
1378 static inline int trace_branch_enable(struct trace_array *tr)
1379 {
1380 	return 0;
1381 }
1382 static inline void trace_branch_disable(void)
1383 {
1384 }
1385 #endif /* CONFIG_BRANCH_TRACER */
1386 
1387 /* set ring buffers to default size if not already done so */
1388 int tracing_update_buffers(struct trace_array *tr);
1389 
1390 union trace_synth_field {
1391 	u8				as_u8;
1392 	u16				as_u16;
1393 	u32				as_u32;
1394 	u64				as_u64;
1395 	struct trace_dynamic_info	as_dynamic;
1396 };
1397 
1398 struct ftrace_event_field {
1399 	struct list_head	link;
1400 	const char		*name;
1401 	const char		*type;
1402 	int			filter_type;
1403 	int			offset;
1404 	int			size;
1405 	int			is_signed;
1406 	int			len;
1407 };
1408 
1409 struct prog_entry;
1410 
1411 struct event_filter {
1412 	struct prog_entry __rcu	*prog;
1413 	char			*filter_string;
1414 };
1415 
1416 struct event_subsystem {
1417 	struct list_head	list;
1418 	const char		*name;
1419 	struct event_filter	*filter;
1420 	int			ref_count;
1421 };
1422 
1423 struct trace_subsystem_dir {
1424 	struct list_head		list;
1425 	struct event_subsystem		*subsystem;
1426 	struct trace_array		*tr;
1427 	struct eventfs_inode		*ei;
1428 	int				ref_count;
1429 	int				nr_events;
1430 };
1431 
1432 extern int call_filter_check_discard(struct trace_event_call *call, void *rec,
1433 				     struct trace_buffer *buffer,
1434 				     struct ring_buffer_event *event);
1435 
1436 void trace_buffer_unlock_commit_regs(struct trace_array *tr,
1437 				     struct trace_buffer *buffer,
1438 				     struct ring_buffer_event *event,
1439 				     unsigned int trcace_ctx,
1440 				     struct pt_regs *regs);
1441 
1442 static inline void trace_buffer_unlock_commit(struct trace_array *tr,
1443 					      struct trace_buffer *buffer,
1444 					      struct ring_buffer_event *event,
1445 					      unsigned int trace_ctx)
1446 {
1447 	trace_buffer_unlock_commit_regs(tr, buffer, event, trace_ctx, NULL);
1448 }
1449 
1450 DECLARE_PER_CPU(bool, trace_taskinfo_save);
1451 int trace_save_cmdline(struct task_struct *tsk);
1452 int trace_create_savedcmd(void);
1453 int trace_alloc_tgid_map(void);
1454 void trace_free_saved_cmdlines_buffer(void);
1455 
1456 extern const struct file_operations tracing_saved_cmdlines_fops;
1457 extern const struct file_operations tracing_saved_tgids_fops;
1458 extern const struct file_operations tracing_saved_cmdlines_size_fops;
1459 
1460 DECLARE_PER_CPU(struct ring_buffer_event *, trace_buffered_event);
1461 DECLARE_PER_CPU(int, trace_buffered_event_cnt);
1462 void trace_buffered_event_disable(void);
1463 void trace_buffered_event_enable(void);
1464 
1465 void early_enable_events(struct trace_array *tr, char *buf, bool disable_first);
1466 
1467 static inline void
1468 __trace_event_discard_commit(struct trace_buffer *buffer,
1469 			     struct ring_buffer_event *event)
1470 {
1471 	if (this_cpu_read(trace_buffered_event) == event) {
1472 		/* Simply release the temp buffer and enable preemption */
1473 		this_cpu_dec(trace_buffered_event_cnt);
1474 		preempt_enable_notrace();
1475 		return;
1476 	}
1477 	/* ring_buffer_discard_commit() enables preemption */
1478 	ring_buffer_discard_commit(buffer, event);
1479 }
1480 
1481 /*
1482  * Helper function for event_trigger_unlock_commit{_regs}().
1483  * If there are event triggers attached to this event that requires
1484  * filtering against its fields, then they will be called as the
1485  * entry already holds the field information of the current event.
1486  *
1487  * It also checks if the event should be discarded or not.
1488  * It is to be discarded if the event is soft disabled and the
1489  * event was only recorded to process triggers, or if the event
1490  * filter is active and this event did not match the filters.
1491  *
1492  * Returns true if the event is discarded, false otherwise.
1493  */
1494 static inline bool
1495 __event_trigger_test_discard(struct trace_event_file *file,
1496 			     struct trace_buffer *buffer,
1497 			     struct ring_buffer_event *event,
1498 			     void *entry,
1499 			     enum event_trigger_type *tt)
1500 {
1501 	unsigned long eflags = file->flags;
1502 
1503 	if (eflags & EVENT_FILE_FL_TRIGGER_COND)
1504 		*tt = event_triggers_call(file, buffer, entry, event);
1505 
1506 	if (likely(!(file->flags & (EVENT_FILE_FL_SOFT_DISABLED |
1507 				    EVENT_FILE_FL_FILTERED |
1508 				    EVENT_FILE_FL_PID_FILTER))))
1509 		return false;
1510 
1511 	if (file->flags & EVENT_FILE_FL_SOFT_DISABLED)
1512 		goto discard;
1513 
1514 	if (file->flags & EVENT_FILE_FL_FILTERED &&
1515 	    !filter_match_preds(file->filter, entry))
1516 		goto discard;
1517 
1518 	if ((file->flags & EVENT_FILE_FL_PID_FILTER) &&
1519 	    trace_event_ignore_this_pid(file))
1520 		goto discard;
1521 
1522 	return false;
1523  discard:
1524 	__trace_event_discard_commit(buffer, event);
1525 	return true;
1526 }
1527 
1528 /**
1529  * event_trigger_unlock_commit - handle triggers and finish event commit
1530  * @file: The file pointer associated with the event
1531  * @buffer: The ring buffer that the event is being written to
1532  * @event: The event meta data in the ring buffer
1533  * @entry: The event itself
1534  * @trace_ctx: The tracing context flags.
1535  *
1536  * This is a helper function to handle triggers that require data
1537  * from the event itself. It also tests the event against filters and
1538  * if the event is soft disabled and should be discarded.
1539  */
1540 static inline void
1541 event_trigger_unlock_commit(struct trace_event_file *file,
1542 			    struct trace_buffer *buffer,
1543 			    struct ring_buffer_event *event,
1544 			    void *entry, unsigned int trace_ctx)
1545 {
1546 	enum event_trigger_type tt = ETT_NONE;
1547 
1548 	if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1549 		trace_buffer_unlock_commit(file->tr, buffer, event, trace_ctx);
1550 
1551 	if (tt)
1552 		event_triggers_post_call(file, tt);
1553 }
1554 
1555 #define FILTER_PRED_INVALID	((unsigned short)-1)
1556 #define FILTER_PRED_IS_RIGHT	(1 << 15)
1557 #define FILTER_PRED_FOLD	(1 << 15)
1558 
1559 /*
1560  * The max preds is the size of unsigned short with
1561  * two flags at the MSBs. One bit is used for both the IS_RIGHT
1562  * and FOLD flags. The other is reserved.
1563  *
1564  * 2^14 preds is way more than enough.
1565  */
1566 #define MAX_FILTER_PRED		16384
1567 
1568 struct filter_pred;
1569 struct regex;
1570 
1571 typedef int (*regex_match_func)(char *str, struct regex *r, int len);
1572 
1573 enum regex_type {
1574 	MATCH_FULL = 0,
1575 	MATCH_FRONT_ONLY,
1576 	MATCH_MIDDLE_ONLY,
1577 	MATCH_END_ONLY,
1578 	MATCH_GLOB,
1579 	MATCH_INDEX,
1580 };
1581 
1582 struct regex {
1583 	char			pattern[MAX_FILTER_STR_VAL];
1584 	int			len;
1585 	int			field_len;
1586 	regex_match_func	match;
1587 };
1588 
1589 static inline bool is_string_field(struct ftrace_event_field *field)
1590 {
1591 	return field->filter_type == FILTER_DYN_STRING ||
1592 	       field->filter_type == FILTER_RDYN_STRING ||
1593 	       field->filter_type == FILTER_STATIC_STRING ||
1594 	       field->filter_type == FILTER_PTR_STRING ||
1595 	       field->filter_type == FILTER_COMM;
1596 }
1597 
1598 static inline bool is_function_field(struct ftrace_event_field *field)
1599 {
1600 	return field->filter_type == FILTER_TRACE_FN;
1601 }
1602 
1603 extern enum regex_type
1604 filter_parse_regex(char *buff, int len, char **search, int *not);
1605 extern void print_event_filter(struct trace_event_file *file,
1606 			       struct trace_seq *s);
1607 extern int apply_event_filter(struct trace_event_file *file,
1608 			      char *filter_string);
1609 extern int apply_subsystem_event_filter(struct trace_subsystem_dir *dir,
1610 					char *filter_string);
1611 extern void print_subsystem_event_filter(struct event_subsystem *system,
1612 					 struct trace_seq *s);
1613 extern int filter_assign_type(const char *type);
1614 extern int create_event_filter(struct trace_array *tr,
1615 			       struct trace_event_call *call,
1616 			       char *filter_str, bool set_str,
1617 			       struct event_filter **filterp);
1618 extern void free_event_filter(struct event_filter *filter);
1619 
1620 struct ftrace_event_field *
1621 trace_find_event_field(struct trace_event_call *call, char *name);
1622 
1623 extern void trace_event_enable_cmd_record(bool enable);
1624 extern void trace_event_enable_tgid_record(bool enable);
1625 
1626 extern int event_trace_init(void);
1627 extern int init_events(void);
1628 extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
1629 extern int event_trace_del_tracer(struct trace_array *tr);
1630 extern void __trace_early_add_events(struct trace_array *tr);
1631 
1632 extern struct trace_event_file *__find_event_file(struct trace_array *tr,
1633 						  const char *system,
1634 						  const char *event);
1635 extern struct trace_event_file *find_event_file(struct trace_array *tr,
1636 						const char *system,
1637 						const char *event);
1638 
1639 static inline void *event_file_data(struct file *filp)
1640 {
1641 	return READ_ONCE(file_inode(filp)->i_private);
1642 }
1643 
1644 extern struct mutex event_mutex;
1645 extern struct list_head ftrace_events;
1646 
1647 /*
1648  * When the trace_event_file is the filp->i_private pointer,
1649  * it must be taken under the event_mutex lock, and then checked
1650  * if the EVENT_FILE_FL_FREED flag is set. If it is, then the
1651  * data pointed to by the trace_event_file can not be trusted.
1652  *
1653  * Use the event_file_file() to access the trace_event_file from
1654  * the filp the first time under the event_mutex and check for
1655  * NULL. If it is needed to be retrieved again and the event_mutex
1656  * is still held, then the event_file_data() can be used and it
1657  * is guaranteed to be valid.
1658  */
1659 static inline struct trace_event_file *event_file_file(struct file *filp)
1660 {
1661 	struct trace_event_file *file;
1662 
1663 	lockdep_assert_held(&event_mutex);
1664 	file = READ_ONCE(file_inode(filp)->i_private);
1665 	if (!file || file->flags & EVENT_FILE_FL_FREED)
1666 		return NULL;
1667 	return file;
1668 }
1669 
1670 extern const struct file_operations event_trigger_fops;
1671 extern const struct file_operations event_hist_fops;
1672 extern const struct file_operations event_hist_debug_fops;
1673 extern const struct file_operations event_inject_fops;
1674 
1675 #ifdef CONFIG_HIST_TRIGGERS
1676 extern int register_trigger_hist_cmd(void);
1677 extern int register_trigger_hist_enable_disable_cmds(void);
1678 #else
1679 static inline int register_trigger_hist_cmd(void) { return 0; }
1680 static inline int register_trigger_hist_enable_disable_cmds(void) { return 0; }
1681 #endif
1682 
1683 extern int register_trigger_cmds(void);
1684 extern void clear_event_triggers(struct trace_array *tr);
1685 
1686 enum {
1687 	EVENT_TRIGGER_FL_PROBE		= BIT(0),
1688 };
1689 
1690 struct event_trigger_data {
1691 	unsigned long			count;
1692 	int				ref;
1693 	int				flags;
1694 	struct event_trigger_ops	*ops;
1695 	struct event_command		*cmd_ops;
1696 	struct event_filter __rcu	*filter;
1697 	char				*filter_str;
1698 	void				*private_data;
1699 	bool				paused;
1700 	bool				paused_tmp;
1701 	struct list_head		list;
1702 	char				*name;
1703 	struct list_head		named_list;
1704 	struct event_trigger_data	*named_data;
1705 };
1706 
1707 /* Avoid typos */
1708 #define ENABLE_EVENT_STR	"enable_event"
1709 #define DISABLE_EVENT_STR	"disable_event"
1710 #define ENABLE_HIST_STR		"enable_hist"
1711 #define DISABLE_HIST_STR	"disable_hist"
1712 
1713 struct enable_trigger_data {
1714 	struct trace_event_file		*file;
1715 	bool				enable;
1716 	bool				hist;
1717 };
1718 
1719 extern int event_enable_trigger_print(struct seq_file *m,
1720 				      struct event_trigger_data *data);
1721 extern void event_enable_trigger_free(struct event_trigger_data *data);
1722 extern int event_enable_trigger_parse(struct event_command *cmd_ops,
1723 				      struct trace_event_file *file,
1724 				      char *glob, char *cmd,
1725 				      char *param_and_filter);
1726 extern int event_enable_register_trigger(char *glob,
1727 					 struct event_trigger_data *data,
1728 					 struct trace_event_file *file);
1729 extern void event_enable_unregister_trigger(char *glob,
1730 					    struct event_trigger_data *test,
1731 					    struct trace_event_file *file);
1732 extern void trigger_data_free(struct event_trigger_data *data);
1733 extern int event_trigger_init(struct event_trigger_data *data);
1734 extern int trace_event_trigger_enable_disable(struct trace_event_file *file,
1735 					      int trigger_enable);
1736 extern void update_cond_flag(struct trace_event_file *file);
1737 extern int set_trigger_filter(char *filter_str,
1738 			      struct event_trigger_data *trigger_data,
1739 			      struct trace_event_file *file);
1740 extern struct event_trigger_data *find_named_trigger(const char *name);
1741 extern bool is_named_trigger(struct event_trigger_data *test);
1742 extern int save_named_trigger(const char *name,
1743 			      struct event_trigger_data *data);
1744 extern void del_named_trigger(struct event_trigger_data *data);
1745 extern void pause_named_trigger(struct event_trigger_data *data);
1746 extern void unpause_named_trigger(struct event_trigger_data *data);
1747 extern void set_named_trigger_data(struct event_trigger_data *data,
1748 				   struct event_trigger_data *named_data);
1749 extern struct event_trigger_data *
1750 get_named_trigger_data(struct event_trigger_data *data);
1751 extern int register_event_command(struct event_command *cmd);
1752 extern int unregister_event_command(struct event_command *cmd);
1753 extern int register_trigger_hist_enable_disable_cmds(void);
1754 extern bool event_trigger_check_remove(const char *glob);
1755 extern bool event_trigger_empty_param(const char *param);
1756 extern int event_trigger_separate_filter(char *param_and_filter, char **param,
1757 					 char **filter, bool param_required);
1758 extern struct event_trigger_data *
1759 event_trigger_alloc(struct event_command *cmd_ops,
1760 		    char *cmd,
1761 		    char *param,
1762 		    void *private_data);
1763 extern int event_trigger_parse_num(char *trigger,
1764 				   struct event_trigger_data *trigger_data);
1765 extern int event_trigger_set_filter(struct event_command *cmd_ops,
1766 				    struct trace_event_file *file,
1767 				    char *param,
1768 				    struct event_trigger_data *trigger_data);
1769 extern void event_trigger_reset_filter(struct event_command *cmd_ops,
1770 				       struct event_trigger_data *trigger_data);
1771 extern int event_trigger_register(struct event_command *cmd_ops,
1772 				  struct trace_event_file *file,
1773 				  char *glob,
1774 				  struct event_trigger_data *trigger_data);
1775 extern void event_trigger_unregister(struct event_command *cmd_ops,
1776 				     struct trace_event_file *file,
1777 				     char *glob,
1778 				     struct event_trigger_data *trigger_data);
1779 
1780 extern void event_file_get(struct trace_event_file *file);
1781 extern void event_file_put(struct trace_event_file *file);
1782 
1783 /**
1784  * struct event_trigger_ops - callbacks for trace event triggers
1785  *
1786  * The methods in this structure provide per-event trigger hooks for
1787  * various trigger operations.
1788  *
1789  * The @init and @free methods are used during trigger setup and
1790  * teardown, typically called from an event_command's @parse()
1791  * function implementation.
1792  *
1793  * The @print method is used to print the trigger spec.
1794  *
1795  * The @trigger method is the function that actually implements the
1796  * trigger and is called in the context of the triggering event
1797  * whenever that event occurs.
1798  *
1799  * All the methods below, except for @init() and @free(), must be
1800  * implemented.
1801  *
1802  * @trigger: The trigger 'probe' function called when the triggering
1803  *	event occurs.  The data passed into this callback is the data
1804  *	that was supplied to the event_command @reg() function that
1805  *	registered the trigger (see struct event_command) along with
1806  *	the trace record, rec.
1807  *
1808  * @init: An optional initialization function called for the trigger
1809  *	when the trigger is registered (via the event_command reg()
1810  *	function).  This can be used to perform per-trigger
1811  *	initialization such as incrementing a per-trigger reference
1812  *	count, for instance.  This is usually implemented by the
1813  *	generic utility function @event_trigger_init() (see
1814  *	trace_event_triggers.c).
1815  *
1816  * @free: An optional de-initialization function called for the
1817  *	trigger when the trigger is unregistered (via the
1818  *	event_command @reg() function).  This can be used to perform
1819  *	per-trigger de-initialization such as decrementing a
1820  *	per-trigger reference count and freeing corresponding trigger
1821  *	data, for instance.  This is usually implemented by the
1822  *	generic utility function @event_trigger_free() (see
1823  *	trace_event_triggers.c).
1824  *
1825  * @print: The callback function invoked to have the trigger print
1826  *	itself.  This is usually implemented by a wrapper function
1827  *	that calls the generic utility function @event_trigger_print()
1828  *	(see trace_event_triggers.c).
1829  */
1830 struct event_trigger_ops {
1831 	void			(*trigger)(struct event_trigger_data *data,
1832 					   struct trace_buffer *buffer,
1833 					   void *rec,
1834 					   struct ring_buffer_event *rbe);
1835 	int			(*init)(struct event_trigger_data *data);
1836 	void			(*free)(struct event_trigger_data *data);
1837 	int			(*print)(struct seq_file *m,
1838 					 struct event_trigger_data *data);
1839 };
1840 
1841 /**
1842  * struct event_command - callbacks and data members for event commands
1843  *
1844  * Event commands are invoked by users by writing the command name
1845  * into the 'trigger' file associated with a trace event.  The
1846  * parameters associated with a specific invocation of an event
1847  * command are used to create an event trigger instance, which is
1848  * added to the list of trigger instances associated with that trace
1849  * event.  When the event is hit, the set of triggers associated with
1850  * that event is invoked.
1851  *
1852  * The data members in this structure provide per-event command data
1853  * for various event commands.
1854  *
1855  * All the data members below, except for @post_trigger, must be set
1856  * for each event command.
1857  *
1858  * @name: The unique name that identifies the event command.  This is
1859  *	the name used when setting triggers via trigger files.
1860  *
1861  * @trigger_type: A unique id that identifies the event command
1862  *	'type'.  This value has two purposes, the first to ensure that
1863  *	only one trigger of the same type can be set at a given time
1864  *	for a particular event e.g. it doesn't make sense to have both
1865  *	a traceon and traceoff trigger attached to a single event at
1866  *	the same time, so traceon and traceoff have the same type
1867  *	though they have different names.  The @trigger_type value is
1868  *	also used as a bit value for deferring the actual trigger
1869  *	action until after the current event is finished.  Some
1870  *	commands need to do this if they themselves log to the trace
1871  *	buffer (see the @post_trigger() member below).  @trigger_type
1872  *	values are defined by adding new values to the trigger_type
1873  *	enum in include/linux/trace_events.h.
1874  *
1875  * @flags: See the enum event_command_flags below.
1876  *
1877  * All the methods below, except for @set_filter() and @unreg_all(),
1878  * must be implemented.
1879  *
1880  * @parse: The callback function responsible for parsing and
1881  *	registering the trigger written to the 'trigger' file by the
1882  *	user.  It allocates the trigger instance and registers it with
1883  *	the appropriate trace event.  It makes use of the other
1884  *	event_command callback functions to orchestrate this, and is
1885  *	usually implemented by the generic utility function
1886  *	@event_trigger_callback() (see trace_event_triggers.c).
1887  *
1888  * @reg: Adds the trigger to the list of triggers associated with the
1889  *	event, and enables the event trigger itself, after
1890  *	initializing it (via the event_trigger_ops @init() function).
1891  *	This is also where commands can use the @trigger_type value to
1892  *	make the decision as to whether or not multiple instances of
1893  *	the trigger should be allowed.  This is usually implemented by
1894  *	the generic utility function @register_trigger() (see
1895  *	trace_event_triggers.c).
1896  *
1897  * @unreg: Removes the trigger from the list of triggers associated
1898  *	with the event, and disables the event trigger itself, after
1899  *	initializing it (via the event_trigger_ops @free() function).
1900  *	This is usually implemented by the generic utility function
1901  *	@unregister_trigger() (see trace_event_triggers.c).
1902  *
1903  * @unreg_all: An optional function called to remove all the triggers
1904  *	from the list of triggers associated with the event.  Called
1905  *	when a trigger file is opened in truncate mode.
1906  *
1907  * @set_filter: An optional function called to parse and set a filter
1908  *	for the trigger.  If no @set_filter() method is set for the
1909  *	event command, filters set by the user for the command will be
1910  *	ignored.  This is usually implemented by the generic utility
1911  *	function @set_trigger_filter() (see trace_event_triggers.c).
1912  *
1913  * @get_trigger_ops: The callback function invoked to retrieve the
1914  *	event_trigger_ops implementation associated with the command.
1915  *	This callback function allows a single event_command to
1916  *	support multiple trigger implementations via different sets of
1917  *	event_trigger_ops, depending on the value of the @param
1918  *	string.
1919  */
1920 struct event_command {
1921 	struct list_head	list;
1922 	char			*name;
1923 	enum event_trigger_type	trigger_type;
1924 	int			flags;
1925 	int			(*parse)(struct event_command *cmd_ops,
1926 					 struct trace_event_file *file,
1927 					 char *glob, char *cmd,
1928 					 char *param_and_filter);
1929 	int			(*reg)(char *glob,
1930 				       struct event_trigger_data *data,
1931 				       struct trace_event_file *file);
1932 	void			(*unreg)(char *glob,
1933 					 struct event_trigger_data *data,
1934 					 struct trace_event_file *file);
1935 	void			(*unreg_all)(struct trace_event_file *file);
1936 	int			(*set_filter)(char *filter_str,
1937 					      struct event_trigger_data *data,
1938 					      struct trace_event_file *file);
1939 	struct event_trigger_ops *(*get_trigger_ops)(char *cmd, char *param);
1940 };
1941 
1942 /**
1943  * enum event_command_flags - flags for struct event_command
1944  *
1945  * @POST_TRIGGER: A flag that says whether or not this command needs
1946  *	to have its action delayed until after the current event has
1947  *	been closed.  Some triggers need to avoid being invoked while
1948  *	an event is currently in the process of being logged, since
1949  *	the trigger may itself log data into the trace buffer.  Thus
1950  *	we make sure the current event is committed before invoking
1951  *	those triggers.  To do that, the trigger invocation is split
1952  *	in two - the first part checks the filter using the current
1953  *	trace record; if a command has the @post_trigger flag set, it
1954  *	sets a bit for itself in the return value, otherwise it
1955  *	directly invokes the trigger.  Once all commands have been
1956  *	either invoked or set their return flag, the current record is
1957  *	either committed or discarded.  At that point, if any commands
1958  *	have deferred their triggers, those commands are finally
1959  *	invoked following the close of the current event.  In other
1960  *	words, if the event_trigger_ops @func() probe implementation
1961  *	itself logs to the trace buffer, this flag should be set,
1962  *	otherwise it can be left unspecified.
1963  *
1964  * @NEEDS_REC: A flag that says whether or not this command needs
1965  *	access to the trace record in order to perform its function,
1966  *	regardless of whether or not it has a filter associated with
1967  *	it (filters make a trigger require access to the trace record
1968  *	but are not always present).
1969  */
1970 enum event_command_flags {
1971 	EVENT_CMD_FL_POST_TRIGGER	= 1,
1972 	EVENT_CMD_FL_NEEDS_REC		= 2,
1973 };
1974 
1975 static inline bool event_command_post_trigger(struct event_command *cmd_ops)
1976 {
1977 	return cmd_ops->flags & EVENT_CMD_FL_POST_TRIGGER;
1978 }
1979 
1980 static inline bool event_command_needs_rec(struct event_command *cmd_ops)
1981 {
1982 	return cmd_ops->flags & EVENT_CMD_FL_NEEDS_REC;
1983 }
1984 
1985 extern int trace_event_enable_disable(struct trace_event_file *file,
1986 				      int enable, int soft_disable);
1987 extern int tracing_alloc_snapshot(void);
1988 extern void tracing_snapshot_cond(struct trace_array *tr, void *cond_data);
1989 extern int tracing_snapshot_cond_enable(struct trace_array *tr, void *cond_data, cond_update_fn_t update);
1990 
1991 extern int tracing_snapshot_cond_disable(struct trace_array *tr);
1992 extern void *tracing_cond_snapshot_data(struct trace_array *tr);
1993 
1994 extern const char *__start___trace_bprintk_fmt[];
1995 extern const char *__stop___trace_bprintk_fmt[];
1996 
1997 extern const char *__start___tracepoint_str[];
1998 extern const char *__stop___tracepoint_str[];
1999 
2000 void trace_printk_control(bool enabled);
2001 void trace_printk_start_comm(void);
2002 int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set);
2003 int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled);
2004 
2005 /* Used from boot time tracer */
2006 extern int trace_set_options(struct trace_array *tr, char *option);
2007 extern int tracing_set_tracer(struct trace_array *tr, const char *buf);
2008 extern ssize_t tracing_resize_ring_buffer(struct trace_array *tr,
2009 					  unsigned long size, int cpu_id);
2010 extern int tracing_set_cpumask(struct trace_array *tr,
2011 				cpumask_var_t tracing_cpumask_new);
2012 
2013 
2014 #define MAX_EVENT_NAME_LEN	64
2015 
2016 extern ssize_t trace_parse_run_command(struct file *file,
2017 		const char __user *buffer, size_t count, loff_t *ppos,
2018 		int (*createfn)(const char *));
2019 
2020 extern unsigned int err_pos(char *cmd, const char *str);
2021 extern void tracing_log_err(struct trace_array *tr,
2022 			    const char *loc, const char *cmd,
2023 			    const char **errs, u8 type, u16 pos);
2024 
2025 /*
2026  * Normal trace_printk() and friends allocates special buffers
2027  * to do the manipulation, as well as saves the print formats
2028  * into sections to display. But the trace infrastructure wants
2029  * to use these without the added overhead at the price of being
2030  * a bit slower (used mainly for warnings, where we don't care
2031  * about performance). The internal_trace_puts() is for such
2032  * a purpose.
2033  */
2034 #define internal_trace_puts(str) __trace_puts(_THIS_IP_, str, strlen(str))
2035 
2036 #undef FTRACE_ENTRY
2037 #define FTRACE_ENTRY(call, struct_name, id, tstruct, print)	\
2038 	extern struct trace_event_call					\
2039 	__aligned(4) event_##call;
2040 #undef FTRACE_ENTRY_DUP
2041 #define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print)	\
2042 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
2043 #undef FTRACE_ENTRY_PACKED
2044 #define FTRACE_ENTRY_PACKED(call, struct_name, id, tstruct, print) \
2045 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
2046 
2047 #include "trace_entries.h"
2048 
2049 #if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_FUNCTION_TRACER)
2050 int perf_ftrace_event_register(struct trace_event_call *call,
2051 			       enum trace_reg type, void *data);
2052 #else
2053 #define perf_ftrace_event_register NULL
2054 #endif
2055 
2056 #ifdef CONFIG_FTRACE_SYSCALLS
2057 void init_ftrace_syscalls(void);
2058 const char *get_syscall_name(int syscall);
2059 #else
2060 static inline void init_ftrace_syscalls(void) { }
2061 static inline const char *get_syscall_name(int syscall)
2062 {
2063 	return NULL;
2064 }
2065 #endif
2066 
2067 #ifdef CONFIG_EVENT_TRACING
2068 void trace_event_init(void);
2069 void trace_event_eval_update(struct trace_eval_map **map, int len);
2070 /* Used from boot time tracer */
2071 extern int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set);
2072 extern int trigger_process_regex(struct trace_event_file *file, char *buff);
2073 #else
2074 static inline void __init trace_event_init(void) { }
2075 static inline void trace_event_eval_update(struct trace_eval_map **map, int len) { }
2076 #endif
2077 
2078 #ifdef CONFIG_TRACER_SNAPSHOT
2079 void tracing_snapshot_instance(struct trace_array *tr);
2080 int tracing_alloc_snapshot_instance(struct trace_array *tr);
2081 int tracing_arm_snapshot(struct trace_array *tr);
2082 void tracing_disarm_snapshot(struct trace_array *tr);
2083 #else
2084 static inline void tracing_snapshot_instance(struct trace_array *tr) { }
2085 static inline int tracing_alloc_snapshot_instance(struct trace_array *tr)
2086 {
2087 	return 0;
2088 }
2089 static inline int tracing_arm_snapshot(struct trace_array *tr) { return 0; }
2090 static inline void tracing_disarm_snapshot(struct trace_array *tr) { }
2091 #endif
2092 
2093 #ifdef CONFIG_PREEMPT_TRACER
2094 void tracer_preempt_on(unsigned long a0, unsigned long a1);
2095 void tracer_preempt_off(unsigned long a0, unsigned long a1);
2096 #else
2097 static inline void tracer_preempt_on(unsigned long a0, unsigned long a1) { }
2098 static inline void tracer_preempt_off(unsigned long a0, unsigned long a1) { }
2099 #endif
2100 #ifdef CONFIG_IRQSOFF_TRACER
2101 void tracer_hardirqs_on(unsigned long a0, unsigned long a1);
2102 void tracer_hardirqs_off(unsigned long a0, unsigned long a1);
2103 #else
2104 static inline void tracer_hardirqs_on(unsigned long a0, unsigned long a1) { }
2105 static inline void tracer_hardirqs_off(unsigned long a0, unsigned long a1) { }
2106 #endif
2107 
2108 /*
2109  * Reset the state of the trace_iterator so that it can read consumed data.
2110  * Normally, the trace_iterator is used for reading the data when it is not
2111  * consumed, and must retain state.
2112  */
2113 static __always_inline void trace_iterator_reset(struct trace_iterator *iter)
2114 {
2115 	memset_startat(iter, 0, seq);
2116 	iter->pos = -1;
2117 }
2118 
2119 /* Check the name is good for event/group/fields */
2120 static inline bool __is_good_name(const char *name, bool hash_ok)
2121 {
2122 	if (!isalpha(*name) && *name != '_' && (!hash_ok || *name != '-'))
2123 		return false;
2124 	while (*++name != '\0') {
2125 		if (!isalpha(*name) && !isdigit(*name) && *name != '_' &&
2126 		    (!hash_ok || *name != '-'))
2127 			return false;
2128 	}
2129 	return true;
2130 }
2131 
2132 /* Check the name is good for event/group/fields */
2133 static inline bool is_good_name(const char *name)
2134 {
2135 	return __is_good_name(name, false);
2136 }
2137 
2138 /* Check the name is good for system */
2139 static inline bool is_good_system_name(const char *name)
2140 {
2141 	return __is_good_name(name, true);
2142 }
2143 
2144 /* Convert certain expected symbols into '_' when generating event names */
2145 static inline void sanitize_event_name(char *name)
2146 {
2147 	while (*name++ != '\0')
2148 		if (*name == ':' || *name == '.')
2149 			*name = '_';
2150 }
2151 
2152 /*
2153  * This is a generic way to read and write a u64 value from a file in tracefs.
2154  *
2155  * The value is stored on the variable pointed by *val. The value needs
2156  * to be at least *min and at most *max. The write is protected by an
2157  * existing *lock.
2158  */
2159 struct trace_min_max_param {
2160 	struct mutex	*lock;
2161 	u64		*val;
2162 	u64		*min;
2163 	u64		*max;
2164 };
2165 
2166 #define U64_STR_SIZE		24	/* 20 digits max */
2167 
2168 extern const struct file_operations trace_min_max_fops;
2169 
2170 #ifdef CONFIG_RV
2171 extern int rv_init_interface(void);
2172 #else
2173 static inline int rv_init_interface(void)
2174 {
2175 	return 0;
2176 }
2177 #endif
2178 
2179 #endif /* _LINUX_KERNEL_TRACE_H */
2180