xref: /linux/kernel/trace/trace.h (revision 8e3ed5440b0c305dcd1d5fa7419bd8066d22ef42)
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 #endif
338 #ifdef CONFIG_TRACER_MAX_TRACE
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 	struct trace_pid_list	__rcu *filtered_pids;
347 	struct trace_pid_list	__rcu *filtered_no_pids;
348 	/*
349 	 * max_lock is used to protect the swapping of buffers
350 	 * when taking a max snapshot. The buffers themselves are
351 	 * protected by per_cpu spinlocks. But the action of the swap
352 	 * needs its own lock.
353 	 *
354 	 * This is defined as a arch_spinlock_t in order to help
355 	 * with performance when lockdep debugging is enabled.
356 	 *
357 	 * It is also used in other places outside the update_max_tr
358 	 * so it needs to be defined outside of the
359 	 * CONFIG_TRACER_MAX_TRACE.
360 	 */
361 	arch_spinlock_t		max_lock;
362 	int			buffer_disabled;
363 #ifdef CONFIG_FTRACE_SYSCALLS
364 	int			sys_refcount_enter;
365 	int			sys_refcount_exit;
366 	struct trace_event_file __rcu *enter_syscall_files[NR_syscalls];
367 	struct trace_event_file __rcu *exit_syscall_files[NR_syscalls];
368 #endif
369 	int			stop_count;
370 	int			clock_id;
371 	int			nr_topts;
372 	bool			clear_trace;
373 	int			buffer_percent;
374 	unsigned int		n_err_log_entries;
375 	struct tracer		*current_trace;
376 	unsigned int		trace_flags;
377 	unsigned char		trace_flags_index[TRACE_FLAGS_MAX_SIZE];
378 	unsigned int		flags;
379 	raw_spinlock_t		start_lock;
380 	const char		*system_names;
381 	struct list_head	err_log;
382 	struct dentry		*dir;
383 	struct dentry		*options;
384 	struct dentry		*percpu_dir;
385 	struct eventfs_inode	*event_dir;
386 	struct trace_options	*topts;
387 	struct list_head	systems;
388 	struct list_head	events;
389 	struct trace_event_file *trace_marker_file;
390 	cpumask_var_t		tracing_cpumask; /* only trace on set CPUs */
391 	/* one per_cpu trace_pipe can be opened by only one user */
392 	cpumask_var_t		pipe_cpumask;
393 	int			ref;
394 	int			trace_ref;
395 #ifdef CONFIG_FUNCTION_TRACER
396 	struct ftrace_ops	*ops;
397 	struct trace_pid_list	__rcu *function_pids;
398 	struct trace_pid_list	__rcu *function_no_pids;
399 #ifdef CONFIG_DYNAMIC_FTRACE
400 	/* All of these are protected by the ftrace_lock */
401 	struct list_head	func_probes;
402 	struct list_head	mod_trace;
403 	struct list_head	mod_notrace;
404 #endif
405 	/* function tracing enabled */
406 	int			function_enabled;
407 #endif
408 	int			no_filter_buffering_ref;
409 	struct list_head	hist_vars;
410 #ifdef CONFIG_TRACER_SNAPSHOT
411 	struct cond_snapshot	*cond_snapshot;
412 #endif
413 	struct trace_func_repeats	__percpu *last_func_repeats;
414 	/*
415 	 * On boot up, the ring buffer is set to the minimum size, so that
416 	 * we do not waste memory on systems that are not using tracing.
417 	 */
418 	bool ring_buffer_expanded;
419 };
420 
421 enum {
422 	TRACE_ARRAY_FL_GLOBAL	= (1 << 0)
423 };
424 
425 extern struct list_head ftrace_trace_arrays;
426 
427 extern struct mutex trace_types_lock;
428 
429 extern int trace_array_get(struct trace_array *tr);
430 extern int tracing_check_open_get_tr(struct trace_array *tr);
431 extern struct trace_array *trace_array_find(const char *instance);
432 extern struct trace_array *trace_array_find_get(const char *instance);
433 
434 extern u64 tracing_event_time_stamp(struct trace_buffer *buffer, struct ring_buffer_event *rbe);
435 extern int tracing_set_filter_buffering(struct trace_array *tr, bool set);
436 extern int tracing_set_clock(struct trace_array *tr, const char *clockstr);
437 
438 extern bool trace_clock_in_ns(struct trace_array *tr);
439 
440 /*
441  * The global tracer (top) should be the first trace array added,
442  * but we check the flag anyway.
443  */
444 static inline struct trace_array *top_trace_array(void)
445 {
446 	struct trace_array *tr;
447 
448 	if (list_empty(&ftrace_trace_arrays))
449 		return NULL;
450 
451 	tr = list_entry(ftrace_trace_arrays.prev,
452 			typeof(*tr), list);
453 	WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
454 	return tr;
455 }
456 
457 #define FTRACE_CMP_TYPE(var, type) \
458 	__builtin_types_compatible_p(typeof(var), type *)
459 
460 #undef IF_ASSIGN
461 #define IF_ASSIGN(var, entry, etype, id)			\
462 	if (FTRACE_CMP_TYPE(var, etype)) {			\
463 		var = (typeof(var))(entry);			\
464 		WARN_ON(id != 0 && (entry)->type != id);	\
465 		break;						\
466 	}
467 
468 /* Will cause compile errors if type is not found. */
469 extern void __ftrace_bad_type(void);
470 
471 /*
472  * The trace_assign_type is a verifier that the entry type is
473  * the same as the type being assigned. To add new types simply
474  * add a line with the following format:
475  *
476  * IF_ASSIGN(var, ent, type, id);
477  *
478  *  Where "type" is the trace type that includes the trace_entry
479  *  as the "ent" item. And "id" is the trace identifier that is
480  *  used in the trace_type enum.
481  *
482  *  If the type can have more than one id, then use zero.
483  */
484 #define trace_assign_type(var, ent)					\
485 	do {								\
486 		IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);	\
487 		IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);	\
488 		IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);	\
489 		IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
490 		IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);	\
491 		IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT);	\
492 		IF_ASSIGN(var, ent, struct bputs_entry, TRACE_BPUTS);	\
493 		IF_ASSIGN(var, ent, struct hwlat_entry, TRACE_HWLAT);	\
494 		IF_ASSIGN(var, ent, struct osnoise_entry, TRACE_OSNOISE);\
495 		IF_ASSIGN(var, ent, struct timerlat_entry, TRACE_TIMERLAT);\
496 		IF_ASSIGN(var, ent, struct raw_data_entry, TRACE_RAW_DATA);\
497 		IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,		\
498 			  TRACE_MMIO_RW);				\
499 		IF_ASSIGN(var, ent, struct trace_mmiotrace_map,		\
500 			  TRACE_MMIO_MAP);				\
501 		IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
502 		IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,	\
503 			  TRACE_GRAPH_ENT);		\
504 		IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,	\
505 			  TRACE_GRAPH_RET);		\
506 		IF_ASSIGN(var, ent, struct func_repeats_entry,		\
507 			  TRACE_FUNC_REPEATS);				\
508 		__ftrace_bad_type();					\
509 	} while (0)
510 
511 /*
512  * An option specific to a tracer. This is a boolean value.
513  * The bit is the bit index that sets its value on the
514  * flags value in struct tracer_flags.
515  */
516 struct tracer_opt {
517 	const char	*name; /* Will appear on the trace_options file */
518 	u32		bit; /* Mask assigned in val field in tracer_flags */
519 };
520 
521 /*
522  * The set of specific options for a tracer. Your tracer
523  * have to set the initial value of the flags val.
524  */
525 struct tracer_flags {
526 	u32			val;
527 	struct tracer_opt	*opts;
528 	struct tracer		*trace;
529 };
530 
531 /* Makes more easy to define a tracer opt */
532 #define TRACER_OPT(s, b)	.name = #s, .bit = b
533 
534 
535 struct trace_option_dentry {
536 	struct tracer_opt		*opt;
537 	struct tracer_flags		*flags;
538 	struct trace_array		*tr;
539 	struct dentry			*entry;
540 };
541 
542 /**
543  * struct tracer - a specific tracer and its callbacks to interact with tracefs
544  * @name: the name chosen to select it on the available_tracers file
545  * @init: called when one switches to this tracer (echo name > current_tracer)
546  * @reset: called when one switches to another tracer
547  * @start: called when tracing is unpaused (echo 1 > tracing_on)
548  * @stop: called when tracing is paused (echo 0 > tracing_on)
549  * @update_thresh: called when tracing_thresh is updated
550  * @open: called when the trace file is opened
551  * @pipe_open: called when the trace_pipe file is opened
552  * @close: called when the trace file is released
553  * @pipe_close: called when the trace_pipe file is released
554  * @read: override the default read callback on trace_pipe
555  * @splice_read: override the default splice_read callback on trace_pipe
556  * @selftest: selftest to run on boot (see trace_selftest.c)
557  * @print_headers: override the first lines that describe your columns
558  * @print_line: callback that prints a trace
559  * @set_flag: signals one of your private flags changed (trace_options file)
560  * @flags: your private flags
561  */
562 struct tracer {
563 	const char		*name;
564 	int			(*init)(struct trace_array *tr);
565 	void			(*reset)(struct trace_array *tr);
566 	void			(*start)(struct trace_array *tr);
567 	void			(*stop)(struct trace_array *tr);
568 	int			(*update_thresh)(struct trace_array *tr);
569 	void			(*open)(struct trace_iterator *iter);
570 	void			(*pipe_open)(struct trace_iterator *iter);
571 	void			(*close)(struct trace_iterator *iter);
572 	void			(*pipe_close)(struct trace_iterator *iter);
573 	ssize_t			(*read)(struct trace_iterator *iter,
574 					struct file *filp, char __user *ubuf,
575 					size_t cnt, loff_t *ppos);
576 	ssize_t			(*splice_read)(struct trace_iterator *iter,
577 					       struct file *filp,
578 					       loff_t *ppos,
579 					       struct pipe_inode_info *pipe,
580 					       size_t len,
581 					       unsigned int flags);
582 #ifdef CONFIG_FTRACE_STARTUP_TEST
583 	int			(*selftest)(struct tracer *trace,
584 					    struct trace_array *tr);
585 #endif
586 	void			(*print_header)(struct seq_file *m);
587 	enum print_line_t	(*print_line)(struct trace_iterator *iter);
588 	/* If you handled the flag setting, return 0 */
589 	int			(*set_flag)(struct trace_array *tr,
590 					    u32 old_flags, u32 bit, int set);
591 	/* Return 0 if OK with change, else return non-zero */
592 	int			(*flag_changed)(struct trace_array *tr,
593 						u32 mask, int set);
594 	struct tracer		*next;
595 	struct tracer_flags	*flags;
596 	int			enabled;
597 	bool			print_max;
598 	bool			allow_instances;
599 #ifdef CONFIG_TRACER_MAX_TRACE
600 	bool			use_max_tr;
601 #endif
602 	/* True if tracer cannot be enabled in kernel param */
603 	bool			noboot;
604 };
605 
606 static inline struct ring_buffer_iter *
607 trace_buffer_iter(struct trace_iterator *iter, int cpu)
608 {
609 	return iter->buffer_iter ? iter->buffer_iter[cpu] : NULL;
610 }
611 
612 int tracer_init(struct tracer *t, struct trace_array *tr);
613 int tracing_is_enabled(void);
614 void tracing_reset_online_cpus(struct array_buffer *buf);
615 void tracing_reset_all_online_cpus(void);
616 void tracing_reset_all_online_cpus_unlocked(void);
617 int tracing_open_generic(struct inode *inode, struct file *filp);
618 int tracing_open_generic_tr(struct inode *inode, struct file *filp);
619 int tracing_release_generic_tr(struct inode *inode, struct file *file);
620 int tracing_open_file_tr(struct inode *inode, struct file *filp);
621 int tracing_release_file_tr(struct inode *inode, struct file *filp);
622 int tracing_single_release_file_tr(struct inode *inode, struct file *filp);
623 bool tracing_is_disabled(void);
624 bool tracer_tracing_is_on(struct trace_array *tr);
625 void tracer_tracing_on(struct trace_array *tr);
626 void tracer_tracing_off(struct trace_array *tr);
627 struct dentry *trace_create_file(const char *name,
628 				 umode_t mode,
629 				 struct dentry *parent,
630 				 void *data,
631 				 const struct file_operations *fops);
632 
633 int tracing_init_dentry(void);
634 
635 struct ring_buffer_event;
636 
637 struct ring_buffer_event *
638 trace_buffer_lock_reserve(struct trace_buffer *buffer,
639 			  int type,
640 			  unsigned long len,
641 			  unsigned int trace_ctx);
642 
643 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
644 						struct trace_array_cpu *data);
645 
646 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
647 					  int *ent_cpu, u64 *ent_ts);
648 
649 void trace_buffer_unlock_commit_nostack(struct trace_buffer *buffer,
650 					struct ring_buffer_event *event);
651 
652 bool trace_is_tracepoint_string(const char *str);
653 const char *trace_event_format(struct trace_iterator *iter, const char *fmt);
654 void trace_check_vprintf(struct trace_iterator *iter, const char *fmt,
655 			 va_list ap) __printf(2, 0);
656 char *trace_iter_expand_format(struct trace_iterator *iter);
657 
658 int trace_empty(struct trace_iterator *iter);
659 
660 void *trace_find_next_entry_inc(struct trace_iterator *iter);
661 
662 void trace_init_global_iter(struct trace_iterator *iter);
663 
664 void tracing_iter_reset(struct trace_iterator *iter, int cpu);
665 
666 unsigned long trace_total_entries_cpu(struct trace_array *tr, int cpu);
667 unsigned long trace_total_entries(struct trace_array *tr);
668 
669 void trace_function(struct trace_array *tr,
670 		    unsigned long ip,
671 		    unsigned long parent_ip,
672 		    unsigned int trace_ctx);
673 void trace_graph_function(struct trace_array *tr,
674 		    unsigned long ip,
675 		    unsigned long parent_ip,
676 		    unsigned int trace_ctx);
677 void trace_latency_header(struct seq_file *m);
678 void trace_default_header(struct seq_file *m);
679 void print_trace_header(struct seq_file *m, struct trace_iterator *iter);
680 
681 void trace_graph_return(struct ftrace_graph_ret *trace);
682 int trace_graph_entry(struct ftrace_graph_ent *trace);
683 void set_graph_array(struct trace_array *tr);
684 
685 void tracing_start_cmdline_record(void);
686 void tracing_stop_cmdline_record(void);
687 void tracing_start_tgid_record(void);
688 void tracing_stop_tgid_record(void);
689 
690 int register_tracer(struct tracer *type);
691 int is_tracing_stopped(void);
692 
693 loff_t tracing_lseek(struct file *file, loff_t offset, int whence);
694 
695 extern cpumask_var_t __read_mostly tracing_buffer_mask;
696 
697 #define for_each_tracing_cpu(cpu)	\
698 	for_each_cpu(cpu, tracing_buffer_mask)
699 
700 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
701 
702 extern unsigned long tracing_thresh;
703 
704 /* PID filtering */
705 
706 extern int pid_max;
707 
708 bool trace_find_filtered_pid(struct trace_pid_list *filtered_pids,
709 			     pid_t search_pid);
710 bool trace_ignore_this_task(struct trace_pid_list *filtered_pids,
711 			    struct trace_pid_list *filtered_no_pids,
712 			    struct task_struct *task);
713 void trace_filter_add_remove_task(struct trace_pid_list *pid_list,
714 				  struct task_struct *self,
715 				  struct task_struct *task);
716 void *trace_pid_next(struct trace_pid_list *pid_list, void *v, loff_t *pos);
717 void *trace_pid_start(struct trace_pid_list *pid_list, loff_t *pos);
718 int trace_pid_show(struct seq_file *m, void *v);
719 int trace_pid_write(struct trace_pid_list *filtered_pids,
720 		    struct trace_pid_list **new_pid_list,
721 		    const char __user *ubuf, size_t cnt);
722 
723 #ifdef CONFIG_TRACER_MAX_TRACE
724 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu,
725 		   void *cond_data);
726 void update_max_tr_single(struct trace_array *tr,
727 			  struct task_struct *tsk, int cpu);
728 
729 #ifdef CONFIG_FSNOTIFY
730 #define LATENCY_FS_NOTIFY
731 #endif
732 #endif /* CONFIG_TRACER_MAX_TRACE */
733 
734 #ifdef LATENCY_FS_NOTIFY
735 void latency_fsnotify(struct trace_array *tr);
736 #else
737 static inline void latency_fsnotify(struct trace_array *tr) { }
738 #endif
739 
740 #ifdef CONFIG_STACKTRACE
741 void __trace_stack(struct trace_array *tr, unsigned int trace_ctx, int skip);
742 #else
743 static inline void __trace_stack(struct trace_array *tr, unsigned int trace_ctx,
744 				 int skip)
745 {
746 }
747 #endif /* CONFIG_STACKTRACE */
748 
749 void trace_last_func_repeats(struct trace_array *tr,
750 			     struct trace_func_repeats *last_info,
751 			     unsigned int trace_ctx);
752 
753 extern u64 ftrace_now(int cpu);
754 
755 extern void trace_find_cmdline(int pid, char comm[]);
756 extern int trace_find_tgid(int pid);
757 extern void trace_event_follow_fork(struct trace_array *tr, bool enable);
758 
759 #ifdef CONFIG_DYNAMIC_FTRACE
760 extern unsigned long ftrace_update_tot_cnt;
761 extern unsigned long ftrace_number_of_pages;
762 extern unsigned long ftrace_number_of_groups;
763 void ftrace_init_trace_array(struct trace_array *tr);
764 #else
765 static inline void ftrace_init_trace_array(struct trace_array *tr) { }
766 #endif
767 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
768 extern int DYN_FTRACE_TEST_NAME(void);
769 #define DYN_FTRACE_TEST_NAME2 trace_selftest_dynamic_test_func2
770 extern int DYN_FTRACE_TEST_NAME2(void);
771 
772 extern void trace_set_ring_buffer_expanded(struct trace_array *tr);
773 extern bool tracing_selftest_disabled;
774 
775 #ifdef CONFIG_FTRACE_STARTUP_TEST
776 extern void __init disable_tracing_selftest(const char *reason);
777 
778 extern int trace_selftest_startup_function(struct tracer *trace,
779 					   struct trace_array *tr);
780 extern int trace_selftest_startup_function_graph(struct tracer *trace,
781 						 struct trace_array *tr);
782 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
783 					  struct trace_array *tr);
784 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
785 					     struct trace_array *tr);
786 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
787 						 struct trace_array *tr);
788 extern int trace_selftest_startup_wakeup(struct tracer *trace,
789 					 struct trace_array *tr);
790 extern int trace_selftest_startup_nop(struct tracer *trace,
791 					 struct trace_array *tr);
792 extern int trace_selftest_startup_branch(struct tracer *trace,
793 					 struct trace_array *tr);
794 /*
795  * Tracer data references selftest functions that only occur
796  * on boot up. These can be __init functions. Thus, when selftests
797  * are enabled, then the tracers need to reference __init functions.
798  */
799 #define __tracer_data		__refdata
800 #else
801 static inline void __init disable_tracing_selftest(const char *reason)
802 {
803 }
804 /* Tracers are seldom changed. Optimize when selftests are disabled. */
805 #define __tracer_data		__read_mostly
806 #endif /* CONFIG_FTRACE_STARTUP_TEST */
807 
808 extern void *head_page(struct trace_array_cpu *data);
809 extern unsigned long long ns2usecs(u64 nsec);
810 extern int
811 trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
812 extern int
813 trace_vprintk(unsigned long ip, const char *fmt, va_list args);
814 extern int
815 trace_array_vprintk(struct trace_array *tr,
816 		    unsigned long ip, const char *fmt, va_list args);
817 int trace_array_printk_buf(struct trace_buffer *buffer,
818 			   unsigned long ip, const char *fmt, ...);
819 void trace_printk_seq(struct trace_seq *s);
820 enum print_line_t print_trace_line(struct trace_iterator *iter);
821 
822 extern char trace_find_mark(unsigned long long duration);
823 
824 struct ftrace_hash;
825 
826 struct ftrace_mod_load {
827 	struct list_head	list;
828 	char			*func;
829 	char			*module;
830 	int			 enable;
831 };
832 
833 enum {
834 	FTRACE_HASH_FL_MOD	= (1 << 0),
835 };
836 
837 struct ftrace_hash {
838 	unsigned long		size_bits;
839 	struct hlist_head	*buckets;
840 	unsigned long		count;
841 	unsigned long		flags;
842 	struct rcu_head		rcu;
843 };
844 
845 struct ftrace_func_entry *
846 ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip);
847 
848 static __always_inline bool ftrace_hash_empty(struct ftrace_hash *hash)
849 {
850 	return !hash || !(hash->count || (hash->flags & FTRACE_HASH_FL_MOD));
851 }
852 
853 /* Standard output formatting function used for function return traces */
854 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
855 
856 /* Flag options */
857 #define TRACE_GRAPH_PRINT_OVERRUN       0x1
858 #define TRACE_GRAPH_PRINT_CPU           0x2
859 #define TRACE_GRAPH_PRINT_OVERHEAD      0x4
860 #define TRACE_GRAPH_PRINT_PROC          0x8
861 #define TRACE_GRAPH_PRINT_DURATION      0x10
862 #define TRACE_GRAPH_PRINT_ABS_TIME      0x20
863 #define TRACE_GRAPH_PRINT_REL_TIME      0x40
864 #define TRACE_GRAPH_PRINT_IRQS          0x80
865 #define TRACE_GRAPH_PRINT_TAIL          0x100
866 #define TRACE_GRAPH_SLEEP_TIME          0x200
867 #define TRACE_GRAPH_GRAPH_TIME          0x400
868 #define TRACE_GRAPH_PRINT_RETVAL        0x800
869 #define TRACE_GRAPH_PRINT_RETVAL_HEX    0x1000
870 #define TRACE_GRAPH_PRINT_FILL_SHIFT	28
871 #define TRACE_GRAPH_PRINT_FILL_MASK	(0x3 << TRACE_GRAPH_PRINT_FILL_SHIFT)
872 
873 extern void ftrace_graph_sleep_time_control(bool enable);
874 
875 #ifdef CONFIG_FUNCTION_PROFILER
876 extern void ftrace_graph_graph_time_control(bool enable);
877 #else
878 static inline void ftrace_graph_graph_time_control(bool enable) { }
879 #endif
880 
881 extern enum print_line_t
882 print_graph_function_flags(struct trace_iterator *iter, u32 flags);
883 extern void print_graph_headers_flags(struct seq_file *s, u32 flags);
884 extern void
885 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
886 extern void graph_trace_open(struct trace_iterator *iter);
887 extern void graph_trace_close(struct trace_iterator *iter);
888 extern int __trace_graph_entry(struct trace_array *tr,
889 			       struct ftrace_graph_ent *trace,
890 			       unsigned int trace_ctx);
891 extern void __trace_graph_return(struct trace_array *tr,
892 				 struct ftrace_graph_ret *trace,
893 				 unsigned int trace_ctx);
894 
895 #ifdef CONFIG_DYNAMIC_FTRACE
896 extern struct ftrace_hash __rcu *ftrace_graph_hash;
897 extern struct ftrace_hash __rcu *ftrace_graph_notrace_hash;
898 
899 static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace)
900 {
901 	unsigned long addr = trace->func;
902 	int ret = 0;
903 	struct ftrace_hash *hash;
904 
905 	preempt_disable_notrace();
906 
907 	/*
908 	 * Have to open code "rcu_dereference_sched()" because the
909 	 * function graph tracer can be called when RCU is not
910 	 * "watching".
911 	 * Protected with schedule_on_each_cpu(ftrace_sync)
912 	 */
913 	hash = rcu_dereference_protected(ftrace_graph_hash, !preemptible());
914 
915 	if (ftrace_hash_empty(hash)) {
916 		ret = 1;
917 		goto out;
918 	}
919 
920 	if (ftrace_lookup_ip(hash, addr)) {
921 
922 		/*
923 		 * This needs to be cleared on the return functions
924 		 * when the depth is zero.
925 		 */
926 		trace_recursion_set(TRACE_GRAPH_BIT);
927 		trace_recursion_set_depth(trace->depth);
928 
929 		/*
930 		 * If no irqs are to be traced, but a set_graph_function
931 		 * is set, and called by an interrupt handler, we still
932 		 * want to trace it.
933 		 */
934 		if (in_hardirq())
935 			trace_recursion_set(TRACE_IRQ_BIT);
936 		else
937 			trace_recursion_clear(TRACE_IRQ_BIT);
938 		ret = 1;
939 	}
940 
941 out:
942 	preempt_enable_notrace();
943 	return ret;
944 }
945 
946 static inline void ftrace_graph_addr_finish(struct ftrace_graph_ret *trace)
947 {
948 	if (trace_recursion_test(TRACE_GRAPH_BIT) &&
949 	    trace->depth == trace_recursion_depth())
950 		trace_recursion_clear(TRACE_GRAPH_BIT);
951 }
952 
953 static inline int ftrace_graph_notrace_addr(unsigned long addr)
954 {
955 	int ret = 0;
956 	struct ftrace_hash *notrace_hash;
957 
958 	preempt_disable_notrace();
959 
960 	/*
961 	 * Have to open code "rcu_dereference_sched()" because the
962 	 * function graph tracer can be called when RCU is not
963 	 * "watching".
964 	 * Protected with schedule_on_each_cpu(ftrace_sync)
965 	 */
966 	notrace_hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
967 						 !preemptible());
968 
969 	if (ftrace_lookup_ip(notrace_hash, addr))
970 		ret = 1;
971 
972 	preempt_enable_notrace();
973 	return ret;
974 }
975 #else
976 static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace)
977 {
978 	return 1;
979 }
980 
981 static inline int ftrace_graph_notrace_addr(unsigned long addr)
982 {
983 	return 0;
984 }
985 static inline void ftrace_graph_addr_finish(struct ftrace_graph_ret *trace)
986 { }
987 #endif /* CONFIG_DYNAMIC_FTRACE */
988 
989 extern unsigned int fgraph_max_depth;
990 
991 static inline bool ftrace_graph_ignore_func(struct ftrace_graph_ent *trace)
992 {
993 	/* trace it when it is-nested-in or is a function enabled. */
994 	return !(trace_recursion_test(TRACE_GRAPH_BIT) ||
995 		 ftrace_graph_addr(trace)) ||
996 		(trace->depth < 0) ||
997 		(fgraph_max_depth && trace->depth >= fgraph_max_depth);
998 }
999 
1000 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
1001 static inline enum print_line_t
1002 print_graph_function_flags(struct trace_iterator *iter, u32 flags)
1003 {
1004 	return TRACE_TYPE_UNHANDLED;
1005 }
1006 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
1007 
1008 extern struct list_head ftrace_pids;
1009 
1010 #ifdef CONFIG_FUNCTION_TRACER
1011 
1012 #define FTRACE_PID_IGNORE	-1
1013 #define FTRACE_PID_TRACE	-2
1014 
1015 struct ftrace_func_command {
1016 	struct list_head	list;
1017 	char			*name;
1018 	int			(*func)(struct trace_array *tr,
1019 					struct ftrace_hash *hash,
1020 					char *func, char *cmd,
1021 					char *params, int enable);
1022 };
1023 extern bool ftrace_filter_param __initdata;
1024 static inline int ftrace_trace_task(struct trace_array *tr)
1025 {
1026 	return this_cpu_read(tr->array_buffer.data->ftrace_ignore_pid) !=
1027 		FTRACE_PID_IGNORE;
1028 }
1029 extern int ftrace_is_dead(void);
1030 int ftrace_create_function_files(struct trace_array *tr,
1031 				 struct dentry *parent);
1032 void ftrace_destroy_function_files(struct trace_array *tr);
1033 int ftrace_allocate_ftrace_ops(struct trace_array *tr);
1034 void ftrace_free_ftrace_ops(struct trace_array *tr);
1035 void ftrace_init_global_array_ops(struct trace_array *tr);
1036 void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func);
1037 void ftrace_reset_array_ops(struct trace_array *tr);
1038 void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer);
1039 void ftrace_init_tracefs_toplevel(struct trace_array *tr,
1040 				  struct dentry *d_tracer);
1041 void ftrace_clear_pids(struct trace_array *tr);
1042 int init_function_trace(void);
1043 void ftrace_pid_follow_fork(struct trace_array *tr, bool enable);
1044 #else
1045 static inline int ftrace_trace_task(struct trace_array *tr)
1046 {
1047 	return 1;
1048 }
1049 static inline int ftrace_is_dead(void) { return 0; }
1050 static inline int
1051 ftrace_create_function_files(struct trace_array *tr,
1052 			     struct dentry *parent)
1053 {
1054 	return 0;
1055 }
1056 static inline int ftrace_allocate_ftrace_ops(struct trace_array *tr)
1057 {
1058 	return 0;
1059 }
1060 static inline void ftrace_free_ftrace_ops(struct trace_array *tr) { }
1061 static inline void ftrace_destroy_function_files(struct trace_array *tr) { }
1062 static inline __init void
1063 ftrace_init_global_array_ops(struct trace_array *tr) { }
1064 static inline void ftrace_reset_array_ops(struct trace_array *tr) { }
1065 static inline void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d) { }
1066 static inline void ftrace_init_tracefs_toplevel(struct trace_array *tr, struct dentry *d) { }
1067 static inline void ftrace_clear_pids(struct trace_array *tr) { }
1068 static inline int init_function_trace(void) { return 0; }
1069 static inline void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) { }
1070 /* ftace_func_t type is not defined, use macro instead of static inline */
1071 #define ftrace_init_array_ops(tr, func) do { } while (0)
1072 #endif /* CONFIG_FUNCTION_TRACER */
1073 
1074 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
1075 
1076 struct ftrace_probe_ops {
1077 	void			(*func)(unsigned long ip,
1078 					unsigned long parent_ip,
1079 					struct trace_array *tr,
1080 					struct ftrace_probe_ops *ops,
1081 					void *data);
1082 	int			(*init)(struct ftrace_probe_ops *ops,
1083 					struct trace_array *tr,
1084 					unsigned long ip, void *init_data,
1085 					void **data);
1086 	void			(*free)(struct ftrace_probe_ops *ops,
1087 					struct trace_array *tr,
1088 					unsigned long ip, void *data);
1089 	int			(*print)(struct seq_file *m,
1090 					 unsigned long ip,
1091 					 struct ftrace_probe_ops *ops,
1092 					 void *data);
1093 };
1094 
1095 struct ftrace_func_mapper;
1096 typedef int (*ftrace_mapper_func)(void *data);
1097 
1098 struct ftrace_func_mapper *allocate_ftrace_func_mapper(void);
1099 void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
1100 					   unsigned long ip);
1101 int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
1102 			       unsigned long ip, void *data);
1103 void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
1104 				   unsigned long ip);
1105 void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
1106 			     ftrace_mapper_func free_func);
1107 
1108 extern int
1109 register_ftrace_function_probe(char *glob, struct trace_array *tr,
1110 			       struct ftrace_probe_ops *ops, void *data);
1111 extern int
1112 unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
1113 				      struct ftrace_probe_ops *ops);
1114 extern void clear_ftrace_function_probes(struct trace_array *tr);
1115 
1116 int register_ftrace_command(struct ftrace_func_command *cmd);
1117 int unregister_ftrace_command(struct ftrace_func_command *cmd);
1118 
1119 void ftrace_create_filter_files(struct ftrace_ops *ops,
1120 				struct dentry *parent);
1121 void ftrace_destroy_filter_files(struct ftrace_ops *ops);
1122 
1123 extern int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
1124 			     int len, int reset);
1125 extern int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
1126 			      int len, int reset);
1127 #else
1128 struct ftrace_func_command;
1129 
1130 static inline __init int register_ftrace_command(struct ftrace_func_command *cmd)
1131 {
1132 	return -EINVAL;
1133 }
1134 static inline __init int unregister_ftrace_command(char *cmd_name)
1135 {
1136 	return -EINVAL;
1137 }
1138 static inline void clear_ftrace_function_probes(struct trace_array *tr)
1139 {
1140 }
1141 
1142 /*
1143  * The ops parameter passed in is usually undefined.
1144  * This must be a macro.
1145  */
1146 #define ftrace_create_filter_files(ops, parent) do { } while (0)
1147 #define ftrace_destroy_filter_files(ops) do { } while (0)
1148 #endif /* CONFIG_FUNCTION_TRACER && CONFIG_DYNAMIC_FTRACE */
1149 
1150 bool ftrace_event_is_function(struct trace_event_call *call);
1151 
1152 /*
1153  * struct trace_parser - servers for reading the user input separated by spaces
1154  * @cont: set if the input is not complete - no final space char was found
1155  * @buffer: holds the parsed user input
1156  * @idx: user input length
1157  * @size: buffer size
1158  */
1159 struct trace_parser {
1160 	bool		cont;
1161 	char		*buffer;
1162 	unsigned	idx;
1163 	unsigned	size;
1164 };
1165 
1166 static inline bool trace_parser_loaded(struct trace_parser *parser)
1167 {
1168 	return (parser->idx != 0);
1169 }
1170 
1171 static inline bool trace_parser_cont(struct trace_parser *parser)
1172 {
1173 	return parser->cont;
1174 }
1175 
1176 static inline void trace_parser_clear(struct trace_parser *parser)
1177 {
1178 	parser->cont = false;
1179 	parser->idx = 0;
1180 }
1181 
1182 extern int trace_parser_get_init(struct trace_parser *parser, int size);
1183 extern void trace_parser_put(struct trace_parser *parser);
1184 extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
1185 	size_t cnt, loff_t *ppos);
1186 
1187 /*
1188  * Only create function graph options if function graph is configured.
1189  */
1190 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1191 # define FGRAPH_FLAGS						\
1192 		C(DISPLAY_GRAPH,	"display-graph"),
1193 #else
1194 # define FGRAPH_FLAGS
1195 #endif
1196 
1197 #ifdef CONFIG_BRANCH_TRACER
1198 # define BRANCH_FLAGS					\
1199 		C(BRANCH,		"branch"),
1200 #else
1201 # define BRANCH_FLAGS
1202 #endif
1203 
1204 #ifdef CONFIG_FUNCTION_TRACER
1205 # define FUNCTION_FLAGS						\
1206 		C(FUNCTION,		"function-trace"),	\
1207 		C(FUNC_FORK,		"function-fork"),
1208 # define FUNCTION_DEFAULT_FLAGS		TRACE_ITER_FUNCTION
1209 #else
1210 # define FUNCTION_FLAGS
1211 # define FUNCTION_DEFAULT_FLAGS		0UL
1212 # define TRACE_ITER_FUNC_FORK		0UL
1213 #endif
1214 
1215 #ifdef CONFIG_STACKTRACE
1216 # define STACK_FLAGS				\
1217 		C(STACKTRACE,		"stacktrace"),
1218 #else
1219 # define STACK_FLAGS
1220 #endif
1221 
1222 /*
1223  * trace_iterator_flags is an enumeration that defines bit
1224  * positions into trace_flags that controls the output.
1225  *
1226  * NOTE: These bits must match the trace_options array in
1227  *       trace.c (this macro guarantees it).
1228  */
1229 #define TRACE_FLAGS						\
1230 		C(PRINT_PARENT,		"print-parent"),	\
1231 		C(SYM_OFFSET,		"sym-offset"),		\
1232 		C(SYM_ADDR,		"sym-addr"),		\
1233 		C(VERBOSE,		"verbose"),		\
1234 		C(RAW,			"raw"),			\
1235 		C(HEX,			"hex"),			\
1236 		C(BIN,			"bin"),			\
1237 		C(BLOCK,		"block"),		\
1238 		C(FIELDS,		"fields"),		\
1239 		C(PRINTK,		"trace_printk"),	\
1240 		C(ANNOTATE,		"annotate"),		\
1241 		C(USERSTACKTRACE,	"userstacktrace"),	\
1242 		C(SYM_USEROBJ,		"sym-userobj"),		\
1243 		C(PRINTK_MSGONLY,	"printk-msg-only"),	\
1244 		C(CONTEXT_INFO,		"context-info"),   /* Print pid/cpu/time */ \
1245 		C(LATENCY_FMT,		"latency-format"),	\
1246 		C(RECORD_CMD,		"record-cmd"),		\
1247 		C(RECORD_TGID,		"record-tgid"),		\
1248 		C(OVERWRITE,		"overwrite"),		\
1249 		C(STOP_ON_FREE,		"disable_on_free"),	\
1250 		C(IRQ_INFO,		"irq-info"),		\
1251 		C(MARKERS,		"markers"),		\
1252 		C(EVENT_FORK,		"event-fork"),		\
1253 		C(PAUSE_ON_TRACE,	"pause-on-trace"),	\
1254 		C(HASH_PTR,		"hash-ptr"),	/* Print hashed pointer */ \
1255 		FUNCTION_FLAGS					\
1256 		FGRAPH_FLAGS					\
1257 		STACK_FLAGS					\
1258 		BRANCH_FLAGS
1259 
1260 /*
1261  * By defining C, we can make TRACE_FLAGS a list of bit names
1262  * that will define the bits for the flag masks.
1263  */
1264 #undef C
1265 #define C(a, b) TRACE_ITER_##a##_BIT
1266 
1267 enum trace_iterator_bits {
1268 	TRACE_FLAGS
1269 	/* Make sure we don't go more than we have bits for */
1270 	TRACE_ITER_LAST_BIT
1271 };
1272 
1273 /*
1274  * By redefining C, we can make TRACE_FLAGS a list of masks that
1275  * use the bits as defined above.
1276  */
1277 #undef C
1278 #define C(a, b) TRACE_ITER_##a = (1 << TRACE_ITER_##a##_BIT)
1279 
1280 enum trace_iterator_flags { TRACE_FLAGS };
1281 
1282 /*
1283  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
1284  * control the output of kernel symbols.
1285  */
1286 #define TRACE_ITER_SYM_MASK \
1287 	(TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
1288 
1289 extern struct tracer nop_trace;
1290 
1291 #ifdef CONFIG_BRANCH_TRACER
1292 extern int enable_branch_tracing(struct trace_array *tr);
1293 extern void disable_branch_tracing(void);
1294 static inline int trace_branch_enable(struct trace_array *tr)
1295 {
1296 	if (tr->trace_flags & TRACE_ITER_BRANCH)
1297 		return enable_branch_tracing(tr);
1298 	return 0;
1299 }
1300 static inline void trace_branch_disable(void)
1301 {
1302 	/* due to races, always disable */
1303 	disable_branch_tracing();
1304 }
1305 #else
1306 static inline int trace_branch_enable(struct trace_array *tr)
1307 {
1308 	return 0;
1309 }
1310 static inline void trace_branch_disable(void)
1311 {
1312 }
1313 #endif /* CONFIG_BRANCH_TRACER */
1314 
1315 /* set ring buffers to default size if not already done so */
1316 int tracing_update_buffers(struct trace_array *tr);
1317 
1318 union trace_synth_field {
1319 	u8				as_u8;
1320 	u16				as_u16;
1321 	u32				as_u32;
1322 	u64				as_u64;
1323 	struct trace_dynamic_info	as_dynamic;
1324 };
1325 
1326 struct ftrace_event_field {
1327 	struct list_head	link;
1328 	const char		*name;
1329 	const char		*type;
1330 	int			filter_type;
1331 	int			offset;
1332 	int			size;
1333 	int			is_signed;
1334 	int			len;
1335 };
1336 
1337 struct prog_entry;
1338 
1339 struct event_filter {
1340 	struct prog_entry __rcu	*prog;
1341 	char			*filter_string;
1342 };
1343 
1344 struct event_subsystem {
1345 	struct list_head	list;
1346 	const char		*name;
1347 	struct event_filter	*filter;
1348 	int			ref_count;
1349 };
1350 
1351 struct trace_subsystem_dir {
1352 	struct list_head		list;
1353 	struct event_subsystem		*subsystem;
1354 	struct trace_array		*tr;
1355 	struct eventfs_inode		*ei;
1356 	int				ref_count;
1357 	int				nr_events;
1358 };
1359 
1360 extern int call_filter_check_discard(struct trace_event_call *call, void *rec,
1361 				     struct trace_buffer *buffer,
1362 				     struct ring_buffer_event *event);
1363 
1364 void trace_buffer_unlock_commit_regs(struct trace_array *tr,
1365 				     struct trace_buffer *buffer,
1366 				     struct ring_buffer_event *event,
1367 				     unsigned int trcace_ctx,
1368 				     struct pt_regs *regs);
1369 
1370 static inline void trace_buffer_unlock_commit(struct trace_array *tr,
1371 					      struct trace_buffer *buffer,
1372 					      struct ring_buffer_event *event,
1373 					      unsigned int trace_ctx)
1374 {
1375 	trace_buffer_unlock_commit_regs(tr, buffer, event, trace_ctx, NULL);
1376 }
1377 
1378 DECLARE_PER_CPU(struct ring_buffer_event *, trace_buffered_event);
1379 DECLARE_PER_CPU(int, trace_buffered_event_cnt);
1380 void trace_buffered_event_disable(void);
1381 void trace_buffered_event_enable(void);
1382 
1383 void early_enable_events(struct trace_array *tr, char *buf, bool disable_first);
1384 
1385 static inline void
1386 __trace_event_discard_commit(struct trace_buffer *buffer,
1387 			     struct ring_buffer_event *event)
1388 {
1389 	if (this_cpu_read(trace_buffered_event) == event) {
1390 		/* Simply release the temp buffer and enable preemption */
1391 		this_cpu_dec(trace_buffered_event_cnt);
1392 		preempt_enable_notrace();
1393 		return;
1394 	}
1395 	/* ring_buffer_discard_commit() enables preemption */
1396 	ring_buffer_discard_commit(buffer, event);
1397 }
1398 
1399 /*
1400  * Helper function for event_trigger_unlock_commit{_regs}().
1401  * If there are event triggers attached to this event that requires
1402  * filtering against its fields, then they will be called as the
1403  * entry already holds the field information of the current event.
1404  *
1405  * It also checks if the event should be discarded or not.
1406  * It is to be discarded if the event is soft disabled and the
1407  * event was only recorded to process triggers, or if the event
1408  * filter is active and this event did not match the filters.
1409  *
1410  * Returns true if the event is discarded, false otherwise.
1411  */
1412 static inline bool
1413 __event_trigger_test_discard(struct trace_event_file *file,
1414 			     struct trace_buffer *buffer,
1415 			     struct ring_buffer_event *event,
1416 			     void *entry,
1417 			     enum event_trigger_type *tt)
1418 {
1419 	unsigned long eflags = file->flags;
1420 
1421 	if (eflags & EVENT_FILE_FL_TRIGGER_COND)
1422 		*tt = event_triggers_call(file, buffer, entry, event);
1423 
1424 	if (likely(!(file->flags & (EVENT_FILE_FL_SOFT_DISABLED |
1425 				    EVENT_FILE_FL_FILTERED |
1426 				    EVENT_FILE_FL_PID_FILTER))))
1427 		return false;
1428 
1429 	if (file->flags & EVENT_FILE_FL_SOFT_DISABLED)
1430 		goto discard;
1431 
1432 	if (file->flags & EVENT_FILE_FL_FILTERED &&
1433 	    !filter_match_preds(file->filter, entry))
1434 		goto discard;
1435 
1436 	if ((file->flags & EVENT_FILE_FL_PID_FILTER) &&
1437 	    trace_event_ignore_this_pid(file))
1438 		goto discard;
1439 
1440 	return false;
1441  discard:
1442 	__trace_event_discard_commit(buffer, event);
1443 	return true;
1444 }
1445 
1446 /**
1447  * event_trigger_unlock_commit - handle triggers and finish event commit
1448  * @file: The file pointer associated with the event
1449  * @buffer: The ring buffer that the event is being written to
1450  * @event: The event meta data in the ring buffer
1451  * @entry: The event itself
1452  * @trace_ctx: The tracing context flags.
1453  *
1454  * This is a helper function to handle triggers that require data
1455  * from the event itself. It also tests the event against filters and
1456  * if the event is soft disabled and should be discarded.
1457  */
1458 static inline void
1459 event_trigger_unlock_commit(struct trace_event_file *file,
1460 			    struct trace_buffer *buffer,
1461 			    struct ring_buffer_event *event,
1462 			    void *entry, unsigned int trace_ctx)
1463 {
1464 	enum event_trigger_type tt = ETT_NONE;
1465 
1466 	if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1467 		trace_buffer_unlock_commit(file->tr, buffer, event, trace_ctx);
1468 
1469 	if (tt)
1470 		event_triggers_post_call(file, tt);
1471 }
1472 
1473 #define FILTER_PRED_INVALID	((unsigned short)-1)
1474 #define FILTER_PRED_IS_RIGHT	(1 << 15)
1475 #define FILTER_PRED_FOLD	(1 << 15)
1476 
1477 /*
1478  * The max preds is the size of unsigned short with
1479  * two flags at the MSBs. One bit is used for both the IS_RIGHT
1480  * and FOLD flags. The other is reserved.
1481  *
1482  * 2^14 preds is way more than enough.
1483  */
1484 #define MAX_FILTER_PRED		16384
1485 
1486 struct filter_pred;
1487 struct regex;
1488 
1489 typedef int (*regex_match_func)(char *str, struct regex *r, int len);
1490 
1491 enum regex_type {
1492 	MATCH_FULL = 0,
1493 	MATCH_FRONT_ONLY,
1494 	MATCH_MIDDLE_ONLY,
1495 	MATCH_END_ONLY,
1496 	MATCH_GLOB,
1497 	MATCH_INDEX,
1498 };
1499 
1500 struct regex {
1501 	char			pattern[MAX_FILTER_STR_VAL];
1502 	int			len;
1503 	int			field_len;
1504 	regex_match_func	match;
1505 };
1506 
1507 static inline bool is_string_field(struct ftrace_event_field *field)
1508 {
1509 	return field->filter_type == FILTER_DYN_STRING ||
1510 	       field->filter_type == FILTER_RDYN_STRING ||
1511 	       field->filter_type == FILTER_STATIC_STRING ||
1512 	       field->filter_type == FILTER_PTR_STRING ||
1513 	       field->filter_type == FILTER_COMM;
1514 }
1515 
1516 static inline bool is_function_field(struct ftrace_event_field *field)
1517 {
1518 	return field->filter_type == FILTER_TRACE_FN;
1519 }
1520 
1521 extern enum regex_type
1522 filter_parse_regex(char *buff, int len, char **search, int *not);
1523 extern void print_event_filter(struct trace_event_file *file,
1524 			       struct trace_seq *s);
1525 extern int apply_event_filter(struct trace_event_file *file,
1526 			      char *filter_string);
1527 extern int apply_subsystem_event_filter(struct trace_subsystem_dir *dir,
1528 					char *filter_string);
1529 extern void print_subsystem_event_filter(struct event_subsystem *system,
1530 					 struct trace_seq *s);
1531 extern int filter_assign_type(const char *type);
1532 extern int create_event_filter(struct trace_array *tr,
1533 			       struct trace_event_call *call,
1534 			       char *filter_str, bool set_str,
1535 			       struct event_filter **filterp);
1536 extern void free_event_filter(struct event_filter *filter);
1537 
1538 struct ftrace_event_field *
1539 trace_find_event_field(struct trace_event_call *call, char *name);
1540 
1541 extern void trace_event_enable_cmd_record(bool enable);
1542 extern void trace_event_enable_tgid_record(bool enable);
1543 
1544 extern int event_trace_init(void);
1545 extern int init_events(void);
1546 extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
1547 extern int event_trace_del_tracer(struct trace_array *tr);
1548 extern void __trace_early_add_events(struct trace_array *tr);
1549 
1550 extern struct trace_event_file *__find_event_file(struct trace_array *tr,
1551 						  const char *system,
1552 						  const char *event);
1553 extern struct trace_event_file *find_event_file(struct trace_array *tr,
1554 						const char *system,
1555 						const char *event);
1556 
1557 static inline void *event_file_data(struct file *filp)
1558 {
1559 	return READ_ONCE(file_inode(filp)->i_private);
1560 }
1561 
1562 extern struct mutex event_mutex;
1563 extern struct list_head ftrace_events;
1564 
1565 extern const struct file_operations event_trigger_fops;
1566 extern const struct file_operations event_hist_fops;
1567 extern const struct file_operations event_hist_debug_fops;
1568 extern const struct file_operations event_inject_fops;
1569 
1570 #ifdef CONFIG_HIST_TRIGGERS
1571 extern int register_trigger_hist_cmd(void);
1572 extern int register_trigger_hist_enable_disable_cmds(void);
1573 #else
1574 static inline int register_trigger_hist_cmd(void) { return 0; }
1575 static inline int register_trigger_hist_enable_disable_cmds(void) { return 0; }
1576 #endif
1577 
1578 extern int register_trigger_cmds(void);
1579 extern void clear_event_triggers(struct trace_array *tr);
1580 
1581 enum {
1582 	EVENT_TRIGGER_FL_PROBE		= BIT(0),
1583 };
1584 
1585 struct event_trigger_data {
1586 	unsigned long			count;
1587 	int				ref;
1588 	int				flags;
1589 	struct event_trigger_ops	*ops;
1590 	struct event_command		*cmd_ops;
1591 	struct event_filter __rcu	*filter;
1592 	char				*filter_str;
1593 	void				*private_data;
1594 	bool				paused;
1595 	bool				paused_tmp;
1596 	struct list_head		list;
1597 	char				*name;
1598 	struct list_head		named_list;
1599 	struct event_trigger_data	*named_data;
1600 };
1601 
1602 /* Avoid typos */
1603 #define ENABLE_EVENT_STR	"enable_event"
1604 #define DISABLE_EVENT_STR	"disable_event"
1605 #define ENABLE_HIST_STR		"enable_hist"
1606 #define DISABLE_HIST_STR	"disable_hist"
1607 
1608 struct enable_trigger_data {
1609 	struct trace_event_file		*file;
1610 	bool				enable;
1611 	bool				hist;
1612 };
1613 
1614 extern int event_enable_trigger_print(struct seq_file *m,
1615 				      struct event_trigger_data *data);
1616 extern void event_enable_trigger_free(struct event_trigger_data *data);
1617 extern int event_enable_trigger_parse(struct event_command *cmd_ops,
1618 				      struct trace_event_file *file,
1619 				      char *glob, char *cmd,
1620 				      char *param_and_filter);
1621 extern int event_enable_register_trigger(char *glob,
1622 					 struct event_trigger_data *data,
1623 					 struct trace_event_file *file);
1624 extern void event_enable_unregister_trigger(char *glob,
1625 					    struct event_trigger_data *test,
1626 					    struct trace_event_file *file);
1627 extern void trigger_data_free(struct event_trigger_data *data);
1628 extern int event_trigger_init(struct event_trigger_data *data);
1629 extern int trace_event_trigger_enable_disable(struct trace_event_file *file,
1630 					      int trigger_enable);
1631 extern void update_cond_flag(struct trace_event_file *file);
1632 extern int set_trigger_filter(char *filter_str,
1633 			      struct event_trigger_data *trigger_data,
1634 			      struct trace_event_file *file);
1635 extern struct event_trigger_data *find_named_trigger(const char *name);
1636 extern bool is_named_trigger(struct event_trigger_data *test);
1637 extern int save_named_trigger(const char *name,
1638 			      struct event_trigger_data *data);
1639 extern void del_named_trigger(struct event_trigger_data *data);
1640 extern void pause_named_trigger(struct event_trigger_data *data);
1641 extern void unpause_named_trigger(struct event_trigger_data *data);
1642 extern void set_named_trigger_data(struct event_trigger_data *data,
1643 				   struct event_trigger_data *named_data);
1644 extern struct event_trigger_data *
1645 get_named_trigger_data(struct event_trigger_data *data);
1646 extern int register_event_command(struct event_command *cmd);
1647 extern int unregister_event_command(struct event_command *cmd);
1648 extern int register_trigger_hist_enable_disable_cmds(void);
1649 extern bool event_trigger_check_remove(const char *glob);
1650 extern bool event_trigger_empty_param(const char *param);
1651 extern int event_trigger_separate_filter(char *param_and_filter, char **param,
1652 					 char **filter, bool param_required);
1653 extern struct event_trigger_data *
1654 event_trigger_alloc(struct event_command *cmd_ops,
1655 		    char *cmd,
1656 		    char *param,
1657 		    void *private_data);
1658 extern int event_trigger_parse_num(char *trigger,
1659 				   struct event_trigger_data *trigger_data);
1660 extern int event_trigger_set_filter(struct event_command *cmd_ops,
1661 				    struct trace_event_file *file,
1662 				    char *param,
1663 				    struct event_trigger_data *trigger_data);
1664 extern void event_trigger_reset_filter(struct event_command *cmd_ops,
1665 				       struct event_trigger_data *trigger_data);
1666 extern int event_trigger_register(struct event_command *cmd_ops,
1667 				  struct trace_event_file *file,
1668 				  char *glob,
1669 				  struct event_trigger_data *trigger_data);
1670 extern void event_trigger_unregister(struct event_command *cmd_ops,
1671 				     struct trace_event_file *file,
1672 				     char *glob,
1673 				     struct event_trigger_data *trigger_data);
1674 
1675 extern void event_file_get(struct trace_event_file *file);
1676 extern void event_file_put(struct trace_event_file *file);
1677 
1678 /**
1679  * struct event_trigger_ops - callbacks for trace event triggers
1680  *
1681  * The methods in this structure provide per-event trigger hooks for
1682  * various trigger operations.
1683  *
1684  * The @init and @free methods are used during trigger setup and
1685  * teardown, typically called from an event_command's @parse()
1686  * function implementation.
1687  *
1688  * The @print method is used to print the trigger spec.
1689  *
1690  * The @trigger method is the function that actually implements the
1691  * trigger and is called in the context of the triggering event
1692  * whenever that event occurs.
1693  *
1694  * All the methods below, except for @init() and @free(), must be
1695  * implemented.
1696  *
1697  * @trigger: The trigger 'probe' function called when the triggering
1698  *	event occurs.  The data passed into this callback is the data
1699  *	that was supplied to the event_command @reg() function that
1700  *	registered the trigger (see struct event_command) along with
1701  *	the trace record, rec.
1702  *
1703  * @init: An optional initialization function called for the trigger
1704  *	when the trigger is registered (via the event_command reg()
1705  *	function).  This can be used to perform per-trigger
1706  *	initialization such as incrementing a per-trigger reference
1707  *	count, for instance.  This is usually implemented by the
1708  *	generic utility function @event_trigger_init() (see
1709  *	trace_event_triggers.c).
1710  *
1711  * @free: An optional de-initialization function called for the
1712  *	trigger when the trigger is unregistered (via the
1713  *	event_command @reg() function).  This can be used to perform
1714  *	per-trigger de-initialization such as decrementing a
1715  *	per-trigger reference count and freeing corresponding trigger
1716  *	data, for instance.  This is usually implemented by the
1717  *	generic utility function @event_trigger_free() (see
1718  *	trace_event_triggers.c).
1719  *
1720  * @print: The callback function invoked to have the trigger print
1721  *	itself.  This is usually implemented by a wrapper function
1722  *	that calls the generic utility function @event_trigger_print()
1723  *	(see trace_event_triggers.c).
1724  */
1725 struct event_trigger_ops {
1726 	void			(*trigger)(struct event_trigger_data *data,
1727 					   struct trace_buffer *buffer,
1728 					   void *rec,
1729 					   struct ring_buffer_event *rbe);
1730 	int			(*init)(struct event_trigger_data *data);
1731 	void			(*free)(struct event_trigger_data *data);
1732 	int			(*print)(struct seq_file *m,
1733 					 struct event_trigger_data *data);
1734 };
1735 
1736 /**
1737  * struct event_command - callbacks and data members for event commands
1738  *
1739  * Event commands are invoked by users by writing the command name
1740  * into the 'trigger' file associated with a trace event.  The
1741  * parameters associated with a specific invocation of an event
1742  * command are used to create an event trigger instance, which is
1743  * added to the list of trigger instances associated with that trace
1744  * event.  When the event is hit, the set of triggers associated with
1745  * that event is invoked.
1746  *
1747  * The data members in this structure provide per-event command data
1748  * for various event commands.
1749  *
1750  * All the data members below, except for @post_trigger, must be set
1751  * for each event command.
1752  *
1753  * @name: The unique name that identifies the event command.  This is
1754  *	the name used when setting triggers via trigger files.
1755  *
1756  * @trigger_type: A unique id that identifies the event command
1757  *	'type'.  This value has two purposes, the first to ensure that
1758  *	only one trigger of the same type can be set at a given time
1759  *	for a particular event e.g. it doesn't make sense to have both
1760  *	a traceon and traceoff trigger attached to a single event at
1761  *	the same time, so traceon and traceoff have the same type
1762  *	though they have different names.  The @trigger_type value is
1763  *	also used as a bit value for deferring the actual trigger
1764  *	action until after the current event is finished.  Some
1765  *	commands need to do this if they themselves log to the trace
1766  *	buffer (see the @post_trigger() member below).  @trigger_type
1767  *	values are defined by adding new values to the trigger_type
1768  *	enum in include/linux/trace_events.h.
1769  *
1770  * @flags: See the enum event_command_flags below.
1771  *
1772  * All the methods below, except for @set_filter() and @unreg_all(),
1773  * must be implemented.
1774  *
1775  * @parse: The callback function responsible for parsing and
1776  *	registering the trigger written to the 'trigger' file by the
1777  *	user.  It allocates the trigger instance and registers it with
1778  *	the appropriate trace event.  It makes use of the other
1779  *	event_command callback functions to orchestrate this, and is
1780  *	usually implemented by the generic utility function
1781  *	@event_trigger_callback() (see trace_event_triggers.c).
1782  *
1783  * @reg: Adds the trigger to the list of triggers associated with the
1784  *	event, and enables the event trigger itself, after
1785  *	initializing it (via the event_trigger_ops @init() function).
1786  *	This is also where commands can use the @trigger_type value to
1787  *	make the decision as to whether or not multiple instances of
1788  *	the trigger should be allowed.  This is usually implemented by
1789  *	the generic utility function @register_trigger() (see
1790  *	trace_event_triggers.c).
1791  *
1792  * @unreg: Removes the trigger from the list of triggers associated
1793  *	with the event, and disables the event trigger itself, after
1794  *	initializing it (via the event_trigger_ops @free() function).
1795  *	This is usually implemented by the generic utility function
1796  *	@unregister_trigger() (see trace_event_triggers.c).
1797  *
1798  * @unreg_all: An optional function called to remove all the triggers
1799  *	from the list of triggers associated with the event.  Called
1800  *	when a trigger file is opened in truncate mode.
1801  *
1802  * @set_filter: An optional function called to parse and set a filter
1803  *	for the trigger.  If no @set_filter() method is set for the
1804  *	event command, filters set by the user for the command will be
1805  *	ignored.  This is usually implemented by the generic utility
1806  *	function @set_trigger_filter() (see trace_event_triggers.c).
1807  *
1808  * @get_trigger_ops: The callback function invoked to retrieve the
1809  *	event_trigger_ops implementation associated with the command.
1810  *	This callback function allows a single event_command to
1811  *	support multiple trigger implementations via different sets of
1812  *	event_trigger_ops, depending on the value of the @param
1813  *	string.
1814  */
1815 struct event_command {
1816 	struct list_head	list;
1817 	char			*name;
1818 	enum event_trigger_type	trigger_type;
1819 	int			flags;
1820 	int			(*parse)(struct event_command *cmd_ops,
1821 					 struct trace_event_file *file,
1822 					 char *glob, char *cmd,
1823 					 char *param_and_filter);
1824 	int			(*reg)(char *glob,
1825 				       struct event_trigger_data *data,
1826 				       struct trace_event_file *file);
1827 	void			(*unreg)(char *glob,
1828 					 struct event_trigger_data *data,
1829 					 struct trace_event_file *file);
1830 	void			(*unreg_all)(struct trace_event_file *file);
1831 	int			(*set_filter)(char *filter_str,
1832 					      struct event_trigger_data *data,
1833 					      struct trace_event_file *file);
1834 	struct event_trigger_ops *(*get_trigger_ops)(char *cmd, char *param);
1835 };
1836 
1837 /**
1838  * enum event_command_flags - flags for struct event_command
1839  *
1840  * @POST_TRIGGER: A flag that says whether or not this command needs
1841  *	to have its action delayed until after the current event has
1842  *	been closed.  Some triggers need to avoid being invoked while
1843  *	an event is currently in the process of being logged, since
1844  *	the trigger may itself log data into the trace buffer.  Thus
1845  *	we make sure the current event is committed before invoking
1846  *	those triggers.  To do that, the trigger invocation is split
1847  *	in two - the first part checks the filter using the current
1848  *	trace record; if a command has the @post_trigger flag set, it
1849  *	sets a bit for itself in the return value, otherwise it
1850  *	directly invokes the trigger.  Once all commands have been
1851  *	either invoked or set their return flag, the current record is
1852  *	either committed or discarded.  At that point, if any commands
1853  *	have deferred their triggers, those commands are finally
1854  *	invoked following the close of the current event.  In other
1855  *	words, if the event_trigger_ops @func() probe implementation
1856  *	itself logs to the trace buffer, this flag should be set,
1857  *	otherwise it can be left unspecified.
1858  *
1859  * @NEEDS_REC: A flag that says whether or not this command needs
1860  *	access to the trace record in order to perform its function,
1861  *	regardless of whether or not it has a filter associated with
1862  *	it (filters make a trigger require access to the trace record
1863  *	but are not always present).
1864  */
1865 enum event_command_flags {
1866 	EVENT_CMD_FL_POST_TRIGGER	= 1,
1867 	EVENT_CMD_FL_NEEDS_REC		= 2,
1868 };
1869 
1870 static inline bool event_command_post_trigger(struct event_command *cmd_ops)
1871 {
1872 	return cmd_ops->flags & EVENT_CMD_FL_POST_TRIGGER;
1873 }
1874 
1875 static inline bool event_command_needs_rec(struct event_command *cmd_ops)
1876 {
1877 	return cmd_ops->flags & EVENT_CMD_FL_NEEDS_REC;
1878 }
1879 
1880 extern int trace_event_enable_disable(struct trace_event_file *file,
1881 				      int enable, int soft_disable);
1882 extern int tracing_alloc_snapshot(void);
1883 extern void tracing_snapshot_cond(struct trace_array *tr, void *cond_data);
1884 extern int tracing_snapshot_cond_enable(struct trace_array *tr, void *cond_data, cond_update_fn_t update);
1885 
1886 extern int tracing_snapshot_cond_disable(struct trace_array *tr);
1887 extern void *tracing_cond_snapshot_data(struct trace_array *tr);
1888 
1889 extern const char *__start___trace_bprintk_fmt[];
1890 extern const char *__stop___trace_bprintk_fmt[];
1891 
1892 extern const char *__start___tracepoint_str[];
1893 extern const char *__stop___tracepoint_str[];
1894 
1895 void trace_printk_control(bool enabled);
1896 void trace_printk_start_comm(void);
1897 int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set);
1898 int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled);
1899 
1900 /* Used from boot time tracer */
1901 extern int trace_set_options(struct trace_array *tr, char *option);
1902 extern int tracing_set_tracer(struct trace_array *tr, const char *buf);
1903 extern ssize_t tracing_resize_ring_buffer(struct trace_array *tr,
1904 					  unsigned long size, int cpu_id);
1905 extern int tracing_set_cpumask(struct trace_array *tr,
1906 				cpumask_var_t tracing_cpumask_new);
1907 
1908 
1909 #define MAX_EVENT_NAME_LEN	64
1910 
1911 extern ssize_t trace_parse_run_command(struct file *file,
1912 		const char __user *buffer, size_t count, loff_t *ppos,
1913 		int (*createfn)(const char *));
1914 
1915 extern unsigned int err_pos(char *cmd, const char *str);
1916 extern void tracing_log_err(struct trace_array *tr,
1917 			    const char *loc, const char *cmd,
1918 			    const char **errs, u8 type, u16 pos);
1919 
1920 /*
1921  * Normal trace_printk() and friends allocates special buffers
1922  * to do the manipulation, as well as saves the print formats
1923  * into sections to display. But the trace infrastructure wants
1924  * to use these without the added overhead at the price of being
1925  * a bit slower (used mainly for warnings, where we don't care
1926  * about performance). The internal_trace_puts() is for such
1927  * a purpose.
1928  */
1929 #define internal_trace_puts(str) __trace_puts(_THIS_IP_, str, strlen(str))
1930 
1931 #undef FTRACE_ENTRY
1932 #define FTRACE_ENTRY(call, struct_name, id, tstruct, print)	\
1933 	extern struct trace_event_call					\
1934 	__aligned(4) event_##call;
1935 #undef FTRACE_ENTRY_DUP
1936 #define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print)	\
1937 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
1938 #undef FTRACE_ENTRY_PACKED
1939 #define FTRACE_ENTRY_PACKED(call, struct_name, id, tstruct, print) \
1940 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
1941 
1942 #include "trace_entries.h"
1943 
1944 #if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_FUNCTION_TRACER)
1945 int perf_ftrace_event_register(struct trace_event_call *call,
1946 			       enum trace_reg type, void *data);
1947 #else
1948 #define perf_ftrace_event_register NULL
1949 #endif
1950 
1951 #ifdef CONFIG_FTRACE_SYSCALLS
1952 void init_ftrace_syscalls(void);
1953 const char *get_syscall_name(int syscall);
1954 #else
1955 static inline void init_ftrace_syscalls(void) { }
1956 static inline const char *get_syscall_name(int syscall)
1957 {
1958 	return NULL;
1959 }
1960 #endif
1961 
1962 #ifdef CONFIG_EVENT_TRACING
1963 void trace_event_init(void);
1964 void trace_event_eval_update(struct trace_eval_map **map, int len);
1965 /* Used from boot time tracer */
1966 extern int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set);
1967 extern int trigger_process_regex(struct trace_event_file *file, char *buff);
1968 #else
1969 static inline void __init trace_event_init(void) { }
1970 static inline void trace_event_eval_update(struct trace_eval_map **map, int len) { }
1971 #endif
1972 
1973 #ifdef CONFIG_TRACER_SNAPSHOT
1974 void tracing_snapshot_instance(struct trace_array *tr);
1975 int tracing_alloc_snapshot_instance(struct trace_array *tr);
1976 #else
1977 static inline void tracing_snapshot_instance(struct trace_array *tr) { }
1978 static inline int tracing_alloc_snapshot_instance(struct trace_array *tr)
1979 {
1980 	return 0;
1981 }
1982 #endif
1983 
1984 #ifdef CONFIG_PREEMPT_TRACER
1985 void tracer_preempt_on(unsigned long a0, unsigned long a1);
1986 void tracer_preempt_off(unsigned long a0, unsigned long a1);
1987 #else
1988 static inline void tracer_preempt_on(unsigned long a0, unsigned long a1) { }
1989 static inline void tracer_preempt_off(unsigned long a0, unsigned long a1) { }
1990 #endif
1991 #ifdef CONFIG_IRQSOFF_TRACER
1992 void tracer_hardirqs_on(unsigned long a0, unsigned long a1);
1993 void tracer_hardirqs_off(unsigned long a0, unsigned long a1);
1994 #else
1995 static inline void tracer_hardirqs_on(unsigned long a0, unsigned long a1) { }
1996 static inline void tracer_hardirqs_off(unsigned long a0, unsigned long a1) { }
1997 #endif
1998 
1999 /*
2000  * Reset the state of the trace_iterator so that it can read consumed data.
2001  * Normally, the trace_iterator is used for reading the data when it is not
2002  * consumed, and must retain state.
2003  */
2004 static __always_inline void trace_iterator_reset(struct trace_iterator *iter)
2005 {
2006 	memset_startat(iter, 0, seq);
2007 	iter->pos = -1;
2008 }
2009 
2010 /* Check the name is good for event/group/fields */
2011 static inline bool __is_good_name(const char *name, bool hash_ok)
2012 {
2013 	if (!isalpha(*name) && *name != '_' && (!hash_ok || *name != '-'))
2014 		return false;
2015 	while (*++name != '\0') {
2016 		if (!isalpha(*name) && !isdigit(*name) && *name != '_' &&
2017 		    (!hash_ok || *name != '-'))
2018 			return false;
2019 	}
2020 	return true;
2021 }
2022 
2023 /* Check the name is good for event/group/fields */
2024 static inline bool is_good_name(const char *name)
2025 {
2026 	return __is_good_name(name, false);
2027 }
2028 
2029 /* Check the name is good for system */
2030 static inline bool is_good_system_name(const char *name)
2031 {
2032 	return __is_good_name(name, true);
2033 }
2034 
2035 /* Convert certain expected symbols into '_' when generating event names */
2036 static inline void sanitize_event_name(char *name)
2037 {
2038 	while (*name++ != '\0')
2039 		if (*name == ':' || *name == '.')
2040 			*name = '_';
2041 }
2042 
2043 /*
2044  * This is a generic way to read and write a u64 value from a file in tracefs.
2045  *
2046  * The value is stored on the variable pointed by *val. The value needs
2047  * to be at least *min and at most *max. The write is protected by an
2048  * existing *lock.
2049  */
2050 struct trace_min_max_param {
2051 	struct mutex	*lock;
2052 	u64		*val;
2053 	u64		*min;
2054 	u64		*max;
2055 };
2056 
2057 #define U64_STR_SIZE		24	/* 20 digits max */
2058 
2059 extern const struct file_operations trace_min_max_fops;
2060 
2061 #ifdef CONFIG_RV
2062 extern int rv_init_interface(void);
2063 #else
2064 static inline int rv_init_interface(void)
2065 {
2066 	return 0;
2067 }
2068 #endif
2069 
2070 #endif /* _LINUX_KERNEL_TRACE_H */
2071