xref: /linux/kernel/trace/trace.h (revision db10cb9b)
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 	struct list_head	err_log;
381 	struct dentry		*dir;
382 	struct dentry		*options;
383 	struct dentry		*percpu_dir;
384 	struct dentry		*event_dir;
385 	struct trace_options	*topts;
386 	struct list_head	systems;
387 	struct list_head	events;
388 	struct trace_event_file *trace_marker_file;
389 	cpumask_var_t		tracing_cpumask; /* only trace on set CPUs */
390 	/* one per_cpu trace_pipe can be opened by only one user */
391 	cpumask_var_t		pipe_cpumask;
392 	int			ref;
393 	int			trace_ref;
394 #ifdef CONFIG_FUNCTION_TRACER
395 	struct ftrace_ops	*ops;
396 	struct trace_pid_list	__rcu *function_pids;
397 	struct trace_pid_list	__rcu *function_no_pids;
398 #ifdef CONFIG_DYNAMIC_FTRACE
399 	/* All of these are protected by the ftrace_lock */
400 	struct list_head	func_probes;
401 	struct list_head	mod_trace;
402 	struct list_head	mod_notrace;
403 #endif
404 	/* function tracing enabled */
405 	int			function_enabled;
406 #endif
407 	int			no_filter_buffering_ref;
408 	struct list_head	hist_vars;
409 #ifdef CONFIG_TRACER_SNAPSHOT
410 	struct cond_snapshot	*cond_snapshot;
411 #endif
412 	struct trace_func_repeats	__percpu *last_func_repeats;
413 };
414 
415 enum {
416 	TRACE_ARRAY_FL_GLOBAL	= (1 << 0)
417 };
418 
419 extern struct list_head ftrace_trace_arrays;
420 
421 extern struct mutex trace_types_lock;
422 
423 extern int trace_array_get(struct trace_array *tr);
424 extern int tracing_check_open_get_tr(struct trace_array *tr);
425 extern struct trace_array *trace_array_find(const char *instance);
426 extern struct trace_array *trace_array_find_get(const char *instance);
427 
428 extern u64 tracing_event_time_stamp(struct trace_buffer *buffer, struct ring_buffer_event *rbe);
429 extern int tracing_set_filter_buffering(struct trace_array *tr, bool set);
430 extern int tracing_set_clock(struct trace_array *tr, const char *clockstr);
431 
432 extern bool trace_clock_in_ns(struct trace_array *tr);
433 
434 /*
435  * The global tracer (top) should be the first trace array added,
436  * but we check the flag anyway.
437  */
438 static inline struct trace_array *top_trace_array(void)
439 {
440 	struct trace_array *tr;
441 
442 	if (list_empty(&ftrace_trace_arrays))
443 		return NULL;
444 
445 	tr = list_entry(ftrace_trace_arrays.prev,
446 			typeof(*tr), list);
447 	WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
448 	return tr;
449 }
450 
451 #define FTRACE_CMP_TYPE(var, type) \
452 	__builtin_types_compatible_p(typeof(var), type *)
453 
454 #undef IF_ASSIGN
455 #define IF_ASSIGN(var, entry, etype, id)			\
456 	if (FTRACE_CMP_TYPE(var, etype)) {			\
457 		var = (typeof(var))(entry);			\
458 		WARN_ON(id != 0 && (entry)->type != id);	\
459 		break;						\
460 	}
461 
462 /* Will cause compile errors if type is not found. */
463 extern void __ftrace_bad_type(void);
464 
465 /*
466  * The trace_assign_type is a verifier that the entry type is
467  * the same as the type being assigned. To add new types simply
468  * add a line with the following format:
469  *
470  * IF_ASSIGN(var, ent, type, id);
471  *
472  *  Where "type" is the trace type that includes the trace_entry
473  *  as the "ent" item. And "id" is the trace identifier that is
474  *  used in the trace_type enum.
475  *
476  *  If the type can have more than one id, then use zero.
477  */
478 #define trace_assign_type(var, ent)					\
479 	do {								\
480 		IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);	\
481 		IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);	\
482 		IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);	\
483 		IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
484 		IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);	\
485 		IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT);	\
486 		IF_ASSIGN(var, ent, struct bputs_entry, TRACE_BPUTS);	\
487 		IF_ASSIGN(var, ent, struct hwlat_entry, TRACE_HWLAT);	\
488 		IF_ASSIGN(var, ent, struct osnoise_entry, TRACE_OSNOISE);\
489 		IF_ASSIGN(var, ent, struct timerlat_entry, TRACE_TIMERLAT);\
490 		IF_ASSIGN(var, ent, struct raw_data_entry, TRACE_RAW_DATA);\
491 		IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,		\
492 			  TRACE_MMIO_RW);				\
493 		IF_ASSIGN(var, ent, struct trace_mmiotrace_map,		\
494 			  TRACE_MMIO_MAP);				\
495 		IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
496 		IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,	\
497 			  TRACE_GRAPH_ENT);		\
498 		IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,	\
499 			  TRACE_GRAPH_RET);		\
500 		IF_ASSIGN(var, ent, struct func_repeats_entry,		\
501 			  TRACE_FUNC_REPEATS);				\
502 		__ftrace_bad_type();					\
503 	} while (0)
504 
505 /*
506  * An option specific to a tracer. This is a boolean value.
507  * The bit is the bit index that sets its value on the
508  * flags value in struct tracer_flags.
509  */
510 struct tracer_opt {
511 	const char	*name; /* Will appear on the trace_options file */
512 	u32		bit; /* Mask assigned in val field in tracer_flags */
513 };
514 
515 /*
516  * The set of specific options for a tracer. Your tracer
517  * have to set the initial value of the flags val.
518  */
519 struct tracer_flags {
520 	u32			val;
521 	struct tracer_opt	*opts;
522 	struct tracer		*trace;
523 };
524 
525 /* Makes more easy to define a tracer opt */
526 #define TRACER_OPT(s, b)	.name = #s, .bit = b
527 
528 
529 struct trace_option_dentry {
530 	struct tracer_opt		*opt;
531 	struct tracer_flags		*flags;
532 	struct trace_array		*tr;
533 	struct dentry			*entry;
534 };
535 
536 /**
537  * struct tracer - a specific tracer and its callbacks to interact with tracefs
538  * @name: the name chosen to select it on the available_tracers file
539  * @init: called when one switches to this tracer (echo name > current_tracer)
540  * @reset: called when one switches to another tracer
541  * @start: called when tracing is unpaused (echo 1 > tracing_on)
542  * @stop: called when tracing is paused (echo 0 > tracing_on)
543  * @update_thresh: called when tracing_thresh is updated
544  * @open: called when the trace file is opened
545  * @pipe_open: called when the trace_pipe file is opened
546  * @close: called when the trace file is released
547  * @pipe_close: called when the trace_pipe file is released
548  * @read: override the default read callback on trace_pipe
549  * @splice_read: override the default splice_read callback on trace_pipe
550  * @selftest: selftest to run on boot (see trace_selftest.c)
551  * @print_headers: override the first lines that describe your columns
552  * @print_line: callback that prints a trace
553  * @set_flag: signals one of your private flags changed (trace_options file)
554  * @flags: your private flags
555  */
556 struct tracer {
557 	const char		*name;
558 	int			(*init)(struct trace_array *tr);
559 	void			(*reset)(struct trace_array *tr);
560 	void			(*start)(struct trace_array *tr);
561 	void			(*stop)(struct trace_array *tr);
562 	int			(*update_thresh)(struct trace_array *tr);
563 	void			(*open)(struct trace_iterator *iter);
564 	void			(*pipe_open)(struct trace_iterator *iter);
565 	void			(*close)(struct trace_iterator *iter);
566 	void			(*pipe_close)(struct trace_iterator *iter);
567 	ssize_t			(*read)(struct trace_iterator *iter,
568 					struct file *filp, char __user *ubuf,
569 					size_t cnt, loff_t *ppos);
570 	ssize_t			(*splice_read)(struct trace_iterator *iter,
571 					       struct file *filp,
572 					       loff_t *ppos,
573 					       struct pipe_inode_info *pipe,
574 					       size_t len,
575 					       unsigned int flags);
576 #ifdef CONFIG_FTRACE_STARTUP_TEST
577 	int			(*selftest)(struct tracer *trace,
578 					    struct trace_array *tr);
579 #endif
580 	void			(*print_header)(struct seq_file *m);
581 	enum print_line_t	(*print_line)(struct trace_iterator *iter);
582 	/* If you handled the flag setting, return 0 */
583 	int			(*set_flag)(struct trace_array *tr,
584 					    u32 old_flags, u32 bit, int set);
585 	/* Return 0 if OK with change, else return non-zero */
586 	int			(*flag_changed)(struct trace_array *tr,
587 						u32 mask, int set);
588 	struct tracer		*next;
589 	struct tracer_flags	*flags;
590 	int			enabled;
591 	bool			print_max;
592 	bool			allow_instances;
593 #ifdef CONFIG_TRACER_MAX_TRACE
594 	bool			use_max_tr;
595 #endif
596 	/* True if tracer cannot be enabled in kernel param */
597 	bool			noboot;
598 };
599 
600 static inline struct ring_buffer_iter *
601 trace_buffer_iter(struct trace_iterator *iter, int cpu)
602 {
603 	return iter->buffer_iter ? iter->buffer_iter[cpu] : NULL;
604 }
605 
606 int tracer_init(struct tracer *t, struct trace_array *tr);
607 int tracing_is_enabled(void);
608 void tracing_reset_online_cpus(struct array_buffer *buf);
609 void tracing_reset_all_online_cpus(void);
610 void tracing_reset_all_online_cpus_unlocked(void);
611 int tracing_open_generic(struct inode *inode, struct file *filp);
612 int tracing_open_generic_tr(struct inode *inode, struct file *filp);
613 int tracing_open_file_tr(struct inode *inode, struct file *filp);
614 int tracing_release_file_tr(struct inode *inode, struct file *filp);
615 bool tracing_is_disabled(void);
616 bool tracer_tracing_is_on(struct trace_array *tr);
617 void tracer_tracing_on(struct trace_array *tr);
618 void tracer_tracing_off(struct trace_array *tr);
619 struct dentry *trace_create_file(const char *name,
620 				 umode_t mode,
621 				 struct dentry *parent,
622 				 void *data,
623 				 const struct file_operations *fops);
624 
625 int tracing_init_dentry(void);
626 
627 struct ring_buffer_event;
628 
629 struct ring_buffer_event *
630 trace_buffer_lock_reserve(struct trace_buffer *buffer,
631 			  int type,
632 			  unsigned long len,
633 			  unsigned int trace_ctx);
634 
635 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
636 						struct trace_array_cpu *data);
637 
638 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
639 					  int *ent_cpu, u64 *ent_ts);
640 
641 void trace_buffer_unlock_commit_nostack(struct trace_buffer *buffer,
642 					struct ring_buffer_event *event);
643 
644 bool trace_is_tracepoint_string(const char *str);
645 const char *trace_event_format(struct trace_iterator *iter, const char *fmt);
646 void trace_check_vprintf(struct trace_iterator *iter, const char *fmt,
647 			 va_list ap) __printf(2, 0);
648 char *trace_iter_expand_format(struct trace_iterator *iter);
649 
650 int trace_empty(struct trace_iterator *iter);
651 
652 void *trace_find_next_entry_inc(struct trace_iterator *iter);
653 
654 void trace_init_global_iter(struct trace_iterator *iter);
655 
656 void tracing_iter_reset(struct trace_iterator *iter, int cpu);
657 
658 unsigned long trace_total_entries_cpu(struct trace_array *tr, int cpu);
659 unsigned long trace_total_entries(struct trace_array *tr);
660 
661 void trace_function(struct trace_array *tr,
662 		    unsigned long ip,
663 		    unsigned long parent_ip,
664 		    unsigned int trace_ctx);
665 void trace_graph_function(struct trace_array *tr,
666 		    unsigned long ip,
667 		    unsigned long parent_ip,
668 		    unsigned int trace_ctx);
669 void trace_latency_header(struct seq_file *m);
670 void trace_default_header(struct seq_file *m);
671 void print_trace_header(struct seq_file *m, struct trace_iterator *iter);
672 
673 void trace_graph_return(struct ftrace_graph_ret *trace);
674 int trace_graph_entry(struct ftrace_graph_ent *trace);
675 void set_graph_array(struct trace_array *tr);
676 
677 void tracing_start_cmdline_record(void);
678 void tracing_stop_cmdline_record(void);
679 void tracing_start_tgid_record(void);
680 void tracing_stop_tgid_record(void);
681 
682 int register_tracer(struct tracer *type);
683 int is_tracing_stopped(void);
684 
685 loff_t tracing_lseek(struct file *file, loff_t offset, int whence);
686 
687 extern cpumask_var_t __read_mostly tracing_buffer_mask;
688 
689 #define for_each_tracing_cpu(cpu)	\
690 	for_each_cpu(cpu, tracing_buffer_mask)
691 
692 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
693 
694 extern unsigned long tracing_thresh;
695 
696 /* PID filtering */
697 
698 extern int pid_max;
699 
700 bool trace_find_filtered_pid(struct trace_pid_list *filtered_pids,
701 			     pid_t search_pid);
702 bool trace_ignore_this_task(struct trace_pid_list *filtered_pids,
703 			    struct trace_pid_list *filtered_no_pids,
704 			    struct task_struct *task);
705 void trace_filter_add_remove_task(struct trace_pid_list *pid_list,
706 				  struct task_struct *self,
707 				  struct task_struct *task);
708 void *trace_pid_next(struct trace_pid_list *pid_list, void *v, loff_t *pos);
709 void *trace_pid_start(struct trace_pid_list *pid_list, loff_t *pos);
710 int trace_pid_show(struct seq_file *m, void *v);
711 int trace_pid_write(struct trace_pid_list *filtered_pids,
712 		    struct trace_pid_list **new_pid_list,
713 		    const char __user *ubuf, size_t cnt);
714 
715 #ifdef CONFIG_TRACER_MAX_TRACE
716 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu,
717 		   void *cond_data);
718 void update_max_tr_single(struct trace_array *tr,
719 			  struct task_struct *tsk, int cpu);
720 
721 #ifdef CONFIG_FSNOTIFY
722 #define LATENCY_FS_NOTIFY
723 #endif
724 #endif /* CONFIG_TRACER_MAX_TRACE */
725 
726 #ifdef LATENCY_FS_NOTIFY
727 void latency_fsnotify(struct trace_array *tr);
728 #else
729 static inline void latency_fsnotify(struct trace_array *tr) { }
730 #endif
731 
732 #ifdef CONFIG_STACKTRACE
733 void __trace_stack(struct trace_array *tr, unsigned int trace_ctx, int skip);
734 #else
735 static inline void __trace_stack(struct trace_array *tr, unsigned int trace_ctx,
736 				 int skip)
737 {
738 }
739 #endif /* CONFIG_STACKTRACE */
740 
741 void trace_last_func_repeats(struct trace_array *tr,
742 			     struct trace_func_repeats *last_info,
743 			     unsigned int trace_ctx);
744 
745 extern u64 ftrace_now(int cpu);
746 
747 extern void trace_find_cmdline(int pid, char comm[]);
748 extern int trace_find_tgid(int pid);
749 extern void trace_event_follow_fork(struct trace_array *tr, bool enable);
750 
751 #ifdef CONFIG_DYNAMIC_FTRACE
752 extern unsigned long ftrace_update_tot_cnt;
753 extern unsigned long ftrace_number_of_pages;
754 extern unsigned long ftrace_number_of_groups;
755 void ftrace_init_trace_array(struct trace_array *tr);
756 #else
757 static inline void ftrace_init_trace_array(struct trace_array *tr) { }
758 #endif
759 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
760 extern int DYN_FTRACE_TEST_NAME(void);
761 #define DYN_FTRACE_TEST_NAME2 trace_selftest_dynamic_test_func2
762 extern int DYN_FTRACE_TEST_NAME2(void);
763 
764 extern bool ring_buffer_expanded;
765 extern bool tracing_selftest_disabled;
766 
767 #ifdef CONFIG_FTRACE_STARTUP_TEST
768 extern void __init disable_tracing_selftest(const char *reason);
769 
770 extern int trace_selftest_startup_function(struct tracer *trace,
771 					   struct trace_array *tr);
772 extern int trace_selftest_startup_function_graph(struct tracer *trace,
773 						 struct trace_array *tr);
774 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
775 					  struct trace_array *tr);
776 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
777 					     struct trace_array *tr);
778 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
779 						 struct trace_array *tr);
780 extern int trace_selftest_startup_wakeup(struct tracer *trace,
781 					 struct trace_array *tr);
782 extern int trace_selftest_startup_nop(struct tracer *trace,
783 					 struct trace_array *tr);
784 extern int trace_selftest_startup_branch(struct tracer *trace,
785 					 struct trace_array *tr);
786 /*
787  * Tracer data references selftest functions that only occur
788  * on boot up. These can be __init functions. Thus, when selftests
789  * are enabled, then the tracers need to reference __init functions.
790  */
791 #define __tracer_data		__refdata
792 #else
793 static inline void __init disable_tracing_selftest(const char *reason)
794 {
795 }
796 /* Tracers are seldom changed. Optimize when selftests are disabled. */
797 #define __tracer_data		__read_mostly
798 #endif /* CONFIG_FTRACE_STARTUP_TEST */
799 
800 extern void *head_page(struct trace_array_cpu *data);
801 extern unsigned long long ns2usecs(u64 nsec);
802 extern int
803 trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
804 extern int
805 trace_vprintk(unsigned long ip, const char *fmt, va_list args);
806 extern int
807 trace_array_vprintk(struct trace_array *tr,
808 		    unsigned long ip, const char *fmt, va_list args);
809 int trace_array_printk_buf(struct trace_buffer *buffer,
810 			   unsigned long ip, const char *fmt, ...);
811 void trace_printk_seq(struct trace_seq *s);
812 enum print_line_t print_trace_line(struct trace_iterator *iter);
813 
814 extern char trace_find_mark(unsigned long long duration);
815 
816 struct ftrace_hash;
817 
818 struct ftrace_mod_load {
819 	struct list_head	list;
820 	char			*func;
821 	char			*module;
822 	int			 enable;
823 };
824 
825 enum {
826 	FTRACE_HASH_FL_MOD	= (1 << 0),
827 };
828 
829 struct ftrace_hash {
830 	unsigned long		size_bits;
831 	struct hlist_head	*buckets;
832 	unsigned long		count;
833 	unsigned long		flags;
834 	struct rcu_head		rcu;
835 };
836 
837 struct ftrace_func_entry *
838 ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip);
839 
840 static __always_inline bool ftrace_hash_empty(struct ftrace_hash *hash)
841 {
842 	return !hash || !(hash->count || (hash->flags & FTRACE_HASH_FL_MOD));
843 }
844 
845 /* Standard output formatting function used for function return traces */
846 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
847 
848 /* Flag options */
849 #define TRACE_GRAPH_PRINT_OVERRUN       0x1
850 #define TRACE_GRAPH_PRINT_CPU           0x2
851 #define TRACE_GRAPH_PRINT_OVERHEAD      0x4
852 #define TRACE_GRAPH_PRINT_PROC          0x8
853 #define TRACE_GRAPH_PRINT_DURATION      0x10
854 #define TRACE_GRAPH_PRINT_ABS_TIME      0x20
855 #define TRACE_GRAPH_PRINT_REL_TIME      0x40
856 #define TRACE_GRAPH_PRINT_IRQS          0x80
857 #define TRACE_GRAPH_PRINT_TAIL          0x100
858 #define TRACE_GRAPH_SLEEP_TIME          0x200
859 #define TRACE_GRAPH_GRAPH_TIME          0x400
860 #define TRACE_GRAPH_PRINT_RETVAL        0x800
861 #define TRACE_GRAPH_PRINT_RETVAL_HEX    0x1000
862 #define TRACE_GRAPH_PRINT_FILL_SHIFT	28
863 #define TRACE_GRAPH_PRINT_FILL_MASK	(0x3 << TRACE_GRAPH_PRINT_FILL_SHIFT)
864 
865 extern void ftrace_graph_sleep_time_control(bool enable);
866 
867 #ifdef CONFIG_FUNCTION_PROFILER
868 extern void ftrace_graph_graph_time_control(bool enable);
869 #else
870 static inline void ftrace_graph_graph_time_control(bool enable) { }
871 #endif
872 
873 extern enum print_line_t
874 print_graph_function_flags(struct trace_iterator *iter, u32 flags);
875 extern void print_graph_headers_flags(struct seq_file *s, u32 flags);
876 extern void
877 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
878 extern void graph_trace_open(struct trace_iterator *iter);
879 extern void graph_trace_close(struct trace_iterator *iter);
880 extern int __trace_graph_entry(struct trace_array *tr,
881 			       struct ftrace_graph_ent *trace,
882 			       unsigned int trace_ctx);
883 extern void __trace_graph_return(struct trace_array *tr,
884 				 struct ftrace_graph_ret *trace,
885 				 unsigned int trace_ctx);
886 
887 #ifdef CONFIG_DYNAMIC_FTRACE
888 extern struct ftrace_hash __rcu *ftrace_graph_hash;
889 extern struct ftrace_hash __rcu *ftrace_graph_notrace_hash;
890 
891 static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace)
892 {
893 	unsigned long addr = trace->func;
894 	int ret = 0;
895 	struct ftrace_hash *hash;
896 
897 	preempt_disable_notrace();
898 
899 	/*
900 	 * Have to open code "rcu_dereference_sched()" because the
901 	 * function graph tracer can be called when RCU is not
902 	 * "watching".
903 	 * Protected with schedule_on_each_cpu(ftrace_sync)
904 	 */
905 	hash = rcu_dereference_protected(ftrace_graph_hash, !preemptible());
906 
907 	if (ftrace_hash_empty(hash)) {
908 		ret = 1;
909 		goto out;
910 	}
911 
912 	if (ftrace_lookup_ip(hash, addr)) {
913 
914 		/*
915 		 * This needs to be cleared on the return functions
916 		 * when the depth is zero.
917 		 */
918 		trace_recursion_set(TRACE_GRAPH_BIT);
919 		trace_recursion_set_depth(trace->depth);
920 
921 		/*
922 		 * If no irqs are to be traced, but a set_graph_function
923 		 * is set, and called by an interrupt handler, we still
924 		 * want to trace it.
925 		 */
926 		if (in_hardirq())
927 			trace_recursion_set(TRACE_IRQ_BIT);
928 		else
929 			trace_recursion_clear(TRACE_IRQ_BIT);
930 		ret = 1;
931 	}
932 
933 out:
934 	preempt_enable_notrace();
935 	return ret;
936 }
937 
938 static inline void ftrace_graph_addr_finish(struct ftrace_graph_ret *trace)
939 {
940 	if (trace_recursion_test(TRACE_GRAPH_BIT) &&
941 	    trace->depth == trace_recursion_depth())
942 		trace_recursion_clear(TRACE_GRAPH_BIT);
943 }
944 
945 static inline int ftrace_graph_notrace_addr(unsigned long addr)
946 {
947 	int ret = 0;
948 	struct ftrace_hash *notrace_hash;
949 
950 	preempt_disable_notrace();
951 
952 	/*
953 	 * Have to open code "rcu_dereference_sched()" because the
954 	 * function graph tracer can be called when RCU is not
955 	 * "watching".
956 	 * Protected with schedule_on_each_cpu(ftrace_sync)
957 	 */
958 	notrace_hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
959 						 !preemptible());
960 
961 	if (ftrace_lookup_ip(notrace_hash, addr))
962 		ret = 1;
963 
964 	preempt_enable_notrace();
965 	return ret;
966 }
967 #else
968 static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace)
969 {
970 	return 1;
971 }
972 
973 static inline int ftrace_graph_notrace_addr(unsigned long addr)
974 {
975 	return 0;
976 }
977 static inline void ftrace_graph_addr_finish(struct ftrace_graph_ret *trace)
978 { }
979 #endif /* CONFIG_DYNAMIC_FTRACE */
980 
981 extern unsigned int fgraph_max_depth;
982 
983 static inline bool ftrace_graph_ignore_func(struct ftrace_graph_ent *trace)
984 {
985 	/* trace it when it is-nested-in or is a function enabled. */
986 	return !(trace_recursion_test(TRACE_GRAPH_BIT) ||
987 		 ftrace_graph_addr(trace)) ||
988 		(trace->depth < 0) ||
989 		(fgraph_max_depth && trace->depth >= fgraph_max_depth);
990 }
991 
992 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
993 static inline enum print_line_t
994 print_graph_function_flags(struct trace_iterator *iter, u32 flags)
995 {
996 	return TRACE_TYPE_UNHANDLED;
997 }
998 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
999 
1000 extern struct list_head ftrace_pids;
1001 
1002 #ifdef CONFIG_FUNCTION_TRACER
1003 
1004 #define FTRACE_PID_IGNORE	-1
1005 #define FTRACE_PID_TRACE	-2
1006 
1007 struct ftrace_func_command {
1008 	struct list_head	list;
1009 	char			*name;
1010 	int			(*func)(struct trace_array *tr,
1011 					struct ftrace_hash *hash,
1012 					char *func, char *cmd,
1013 					char *params, int enable);
1014 };
1015 extern bool ftrace_filter_param __initdata;
1016 static inline int ftrace_trace_task(struct trace_array *tr)
1017 {
1018 	return this_cpu_read(tr->array_buffer.data->ftrace_ignore_pid) !=
1019 		FTRACE_PID_IGNORE;
1020 }
1021 extern int ftrace_is_dead(void);
1022 int ftrace_create_function_files(struct trace_array *tr,
1023 				 struct dentry *parent);
1024 void ftrace_destroy_function_files(struct trace_array *tr);
1025 int ftrace_allocate_ftrace_ops(struct trace_array *tr);
1026 void ftrace_free_ftrace_ops(struct trace_array *tr);
1027 void ftrace_init_global_array_ops(struct trace_array *tr);
1028 void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func);
1029 void ftrace_reset_array_ops(struct trace_array *tr);
1030 void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer);
1031 void ftrace_init_tracefs_toplevel(struct trace_array *tr,
1032 				  struct dentry *d_tracer);
1033 void ftrace_clear_pids(struct trace_array *tr);
1034 int init_function_trace(void);
1035 void ftrace_pid_follow_fork(struct trace_array *tr, bool enable);
1036 #else
1037 static inline int ftrace_trace_task(struct trace_array *tr)
1038 {
1039 	return 1;
1040 }
1041 static inline int ftrace_is_dead(void) { return 0; }
1042 static inline int
1043 ftrace_create_function_files(struct trace_array *tr,
1044 			     struct dentry *parent)
1045 {
1046 	return 0;
1047 }
1048 static inline int ftrace_allocate_ftrace_ops(struct trace_array *tr)
1049 {
1050 	return 0;
1051 }
1052 static inline void ftrace_free_ftrace_ops(struct trace_array *tr) { }
1053 static inline void ftrace_destroy_function_files(struct trace_array *tr) { }
1054 static inline __init void
1055 ftrace_init_global_array_ops(struct trace_array *tr) { }
1056 static inline void ftrace_reset_array_ops(struct trace_array *tr) { }
1057 static inline void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d) { }
1058 static inline void ftrace_init_tracefs_toplevel(struct trace_array *tr, struct dentry *d) { }
1059 static inline void ftrace_clear_pids(struct trace_array *tr) { }
1060 static inline int init_function_trace(void) { return 0; }
1061 static inline void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) { }
1062 /* ftace_func_t type is not defined, use macro instead of static inline */
1063 #define ftrace_init_array_ops(tr, func) do { } while (0)
1064 #endif /* CONFIG_FUNCTION_TRACER */
1065 
1066 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
1067 
1068 struct ftrace_probe_ops {
1069 	void			(*func)(unsigned long ip,
1070 					unsigned long parent_ip,
1071 					struct trace_array *tr,
1072 					struct ftrace_probe_ops *ops,
1073 					void *data);
1074 	int			(*init)(struct ftrace_probe_ops *ops,
1075 					struct trace_array *tr,
1076 					unsigned long ip, void *init_data,
1077 					void **data);
1078 	void			(*free)(struct ftrace_probe_ops *ops,
1079 					struct trace_array *tr,
1080 					unsigned long ip, void *data);
1081 	int			(*print)(struct seq_file *m,
1082 					 unsigned long ip,
1083 					 struct ftrace_probe_ops *ops,
1084 					 void *data);
1085 };
1086 
1087 struct ftrace_func_mapper;
1088 typedef int (*ftrace_mapper_func)(void *data);
1089 
1090 struct ftrace_func_mapper *allocate_ftrace_func_mapper(void);
1091 void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
1092 					   unsigned long ip);
1093 int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
1094 			       unsigned long ip, void *data);
1095 void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
1096 				   unsigned long ip);
1097 void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
1098 			     ftrace_mapper_func free_func);
1099 
1100 extern int
1101 register_ftrace_function_probe(char *glob, struct trace_array *tr,
1102 			       struct ftrace_probe_ops *ops, void *data);
1103 extern int
1104 unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
1105 				      struct ftrace_probe_ops *ops);
1106 extern void clear_ftrace_function_probes(struct trace_array *tr);
1107 
1108 int register_ftrace_command(struct ftrace_func_command *cmd);
1109 int unregister_ftrace_command(struct ftrace_func_command *cmd);
1110 
1111 void ftrace_create_filter_files(struct ftrace_ops *ops,
1112 				struct dentry *parent);
1113 void ftrace_destroy_filter_files(struct ftrace_ops *ops);
1114 
1115 extern int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
1116 			     int len, int reset);
1117 extern int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
1118 			      int len, int reset);
1119 #else
1120 struct ftrace_func_command;
1121 
1122 static inline __init int register_ftrace_command(struct ftrace_func_command *cmd)
1123 {
1124 	return -EINVAL;
1125 }
1126 static inline __init int unregister_ftrace_command(char *cmd_name)
1127 {
1128 	return -EINVAL;
1129 }
1130 static inline void clear_ftrace_function_probes(struct trace_array *tr)
1131 {
1132 }
1133 
1134 /*
1135  * The ops parameter passed in is usually undefined.
1136  * This must be a macro.
1137  */
1138 #define ftrace_create_filter_files(ops, parent) do { } while (0)
1139 #define ftrace_destroy_filter_files(ops) do { } while (0)
1140 #endif /* CONFIG_FUNCTION_TRACER && CONFIG_DYNAMIC_FTRACE */
1141 
1142 bool ftrace_event_is_function(struct trace_event_call *call);
1143 
1144 /*
1145  * struct trace_parser - servers for reading the user input separated by spaces
1146  * @cont: set if the input is not complete - no final space char was found
1147  * @buffer: holds the parsed user input
1148  * @idx: user input length
1149  * @size: buffer size
1150  */
1151 struct trace_parser {
1152 	bool		cont;
1153 	char		*buffer;
1154 	unsigned	idx;
1155 	unsigned	size;
1156 };
1157 
1158 static inline bool trace_parser_loaded(struct trace_parser *parser)
1159 {
1160 	return (parser->idx != 0);
1161 }
1162 
1163 static inline bool trace_parser_cont(struct trace_parser *parser)
1164 {
1165 	return parser->cont;
1166 }
1167 
1168 static inline void trace_parser_clear(struct trace_parser *parser)
1169 {
1170 	parser->cont = false;
1171 	parser->idx = 0;
1172 }
1173 
1174 extern int trace_parser_get_init(struct trace_parser *parser, int size);
1175 extern void trace_parser_put(struct trace_parser *parser);
1176 extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
1177 	size_t cnt, loff_t *ppos);
1178 
1179 /*
1180  * Only create function graph options if function graph is configured.
1181  */
1182 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1183 # define FGRAPH_FLAGS						\
1184 		C(DISPLAY_GRAPH,	"display-graph"),
1185 #else
1186 # define FGRAPH_FLAGS
1187 #endif
1188 
1189 #ifdef CONFIG_BRANCH_TRACER
1190 # define BRANCH_FLAGS					\
1191 		C(BRANCH,		"branch"),
1192 #else
1193 # define BRANCH_FLAGS
1194 #endif
1195 
1196 #ifdef CONFIG_FUNCTION_TRACER
1197 # define FUNCTION_FLAGS						\
1198 		C(FUNCTION,		"function-trace"),	\
1199 		C(FUNC_FORK,		"function-fork"),
1200 # define FUNCTION_DEFAULT_FLAGS		TRACE_ITER_FUNCTION
1201 #else
1202 # define FUNCTION_FLAGS
1203 # define FUNCTION_DEFAULT_FLAGS		0UL
1204 # define TRACE_ITER_FUNC_FORK		0UL
1205 #endif
1206 
1207 #ifdef CONFIG_STACKTRACE
1208 # define STACK_FLAGS				\
1209 		C(STACKTRACE,		"stacktrace"),
1210 #else
1211 # define STACK_FLAGS
1212 #endif
1213 
1214 /*
1215  * trace_iterator_flags is an enumeration that defines bit
1216  * positions into trace_flags that controls the output.
1217  *
1218  * NOTE: These bits must match the trace_options array in
1219  *       trace.c (this macro guarantees it).
1220  */
1221 #define TRACE_FLAGS						\
1222 		C(PRINT_PARENT,		"print-parent"),	\
1223 		C(SYM_OFFSET,		"sym-offset"),		\
1224 		C(SYM_ADDR,		"sym-addr"),		\
1225 		C(VERBOSE,		"verbose"),		\
1226 		C(RAW,			"raw"),			\
1227 		C(HEX,			"hex"),			\
1228 		C(BIN,			"bin"),			\
1229 		C(BLOCK,		"block"),		\
1230 		C(FIELDS,		"fields"),		\
1231 		C(PRINTK,		"trace_printk"),	\
1232 		C(ANNOTATE,		"annotate"),		\
1233 		C(USERSTACKTRACE,	"userstacktrace"),	\
1234 		C(SYM_USEROBJ,		"sym-userobj"),		\
1235 		C(PRINTK_MSGONLY,	"printk-msg-only"),	\
1236 		C(CONTEXT_INFO,		"context-info"),   /* Print pid/cpu/time */ \
1237 		C(LATENCY_FMT,		"latency-format"),	\
1238 		C(RECORD_CMD,		"record-cmd"),		\
1239 		C(RECORD_TGID,		"record-tgid"),		\
1240 		C(OVERWRITE,		"overwrite"),		\
1241 		C(STOP_ON_FREE,		"disable_on_free"),	\
1242 		C(IRQ_INFO,		"irq-info"),		\
1243 		C(MARKERS,		"markers"),		\
1244 		C(EVENT_FORK,		"event-fork"),		\
1245 		C(PAUSE_ON_TRACE,	"pause-on-trace"),	\
1246 		C(HASH_PTR,		"hash-ptr"),	/* Print hashed pointer */ \
1247 		FUNCTION_FLAGS					\
1248 		FGRAPH_FLAGS					\
1249 		STACK_FLAGS					\
1250 		BRANCH_FLAGS
1251 
1252 /*
1253  * By defining C, we can make TRACE_FLAGS a list of bit names
1254  * that will define the bits for the flag masks.
1255  */
1256 #undef C
1257 #define C(a, b) TRACE_ITER_##a##_BIT
1258 
1259 enum trace_iterator_bits {
1260 	TRACE_FLAGS
1261 	/* Make sure we don't go more than we have bits for */
1262 	TRACE_ITER_LAST_BIT
1263 };
1264 
1265 /*
1266  * By redefining C, we can make TRACE_FLAGS a list of masks that
1267  * use the bits as defined above.
1268  */
1269 #undef C
1270 #define C(a, b) TRACE_ITER_##a = (1 << TRACE_ITER_##a##_BIT)
1271 
1272 enum trace_iterator_flags { TRACE_FLAGS };
1273 
1274 /*
1275  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
1276  * control the output of kernel symbols.
1277  */
1278 #define TRACE_ITER_SYM_MASK \
1279 	(TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
1280 
1281 extern struct tracer nop_trace;
1282 
1283 #ifdef CONFIG_BRANCH_TRACER
1284 extern int enable_branch_tracing(struct trace_array *tr);
1285 extern void disable_branch_tracing(void);
1286 static inline int trace_branch_enable(struct trace_array *tr)
1287 {
1288 	if (tr->trace_flags & TRACE_ITER_BRANCH)
1289 		return enable_branch_tracing(tr);
1290 	return 0;
1291 }
1292 static inline void trace_branch_disable(void)
1293 {
1294 	/* due to races, always disable */
1295 	disable_branch_tracing();
1296 }
1297 #else
1298 static inline int trace_branch_enable(struct trace_array *tr)
1299 {
1300 	return 0;
1301 }
1302 static inline void trace_branch_disable(void)
1303 {
1304 }
1305 #endif /* CONFIG_BRANCH_TRACER */
1306 
1307 /* set ring buffers to default size if not already done so */
1308 int tracing_update_buffers(void);
1309 
1310 union trace_synth_field {
1311 	u8				as_u8;
1312 	u16				as_u16;
1313 	u32				as_u32;
1314 	u64				as_u64;
1315 	struct trace_dynamic_info	as_dynamic;
1316 };
1317 
1318 struct ftrace_event_field {
1319 	struct list_head	link;
1320 	const char		*name;
1321 	const char		*type;
1322 	int			filter_type;
1323 	int			offset;
1324 	int			size;
1325 	int			is_signed;
1326 	int			len;
1327 };
1328 
1329 struct prog_entry;
1330 
1331 struct event_filter {
1332 	struct prog_entry __rcu	*prog;
1333 	char			*filter_string;
1334 };
1335 
1336 struct event_subsystem {
1337 	struct list_head	list;
1338 	const char		*name;
1339 	struct event_filter	*filter;
1340 	int			ref_count;
1341 };
1342 
1343 struct trace_subsystem_dir {
1344 	struct list_head		list;
1345 	struct event_subsystem		*subsystem;
1346 	struct trace_array		*tr;
1347 	struct eventfs_file             *ef;
1348 	int				ref_count;
1349 	int				nr_events;
1350 };
1351 
1352 extern int call_filter_check_discard(struct trace_event_call *call, void *rec,
1353 				     struct trace_buffer *buffer,
1354 				     struct ring_buffer_event *event);
1355 
1356 void trace_buffer_unlock_commit_regs(struct trace_array *tr,
1357 				     struct trace_buffer *buffer,
1358 				     struct ring_buffer_event *event,
1359 				     unsigned int trcace_ctx,
1360 				     struct pt_regs *regs);
1361 
1362 static inline void trace_buffer_unlock_commit(struct trace_array *tr,
1363 					      struct trace_buffer *buffer,
1364 					      struct ring_buffer_event *event,
1365 					      unsigned int trace_ctx)
1366 {
1367 	trace_buffer_unlock_commit_regs(tr, buffer, event, trace_ctx, NULL);
1368 }
1369 
1370 DECLARE_PER_CPU(struct ring_buffer_event *, trace_buffered_event);
1371 DECLARE_PER_CPU(int, trace_buffered_event_cnt);
1372 void trace_buffered_event_disable(void);
1373 void trace_buffered_event_enable(void);
1374 
1375 void early_enable_events(struct trace_array *tr, char *buf, bool disable_first);
1376 
1377 static inline void
1378 __trace_event_discard_commit(struct trace_buffer *buffer,
1379 			     struct ring_buffer_event *event)
1380 {
1381 	if (this_cpu_read(trace_buffered_event) == event) {
1382 		/* Simply release the temp buffer and enable preemption */
1383 		this_cpu_dec(trace_buffered_event_cnt);
1384 		preempt_enable_notrace();
1385 		return;
1386 	}
1387 	/* ring_buffer_discard_commit() enables preemption */
1388 	ring_buffer_discard_commit(buffer, event);
1389 }
1390 
1391 /*
1392  * Helper function for event_trigger_unlock_commit{_regs}().
1393  * If there are event triggers attached to this event that requires
1394  * filtering against its fields, then they will be called as the
1395  * entry already holds the field information of the current event.
1396  *
1397  * It also checks if the event should be discarded or not.
1398  * It is to be discarded if the event is soft disabled and the
1399  * event was only recorded to process triggers, or if the event
1400  * filter is active and this event did not match the filters.
1401  *
1402  * Returns true if the event is discarded, false otherwise.
1403  */
1404 static inline bool
1405 __event_trigger_test_discard(struct trace_event_file *file,
1406 			     struct trace_buffer *buffer,
1407 			     struct ring_buffer_event *event,
1408 			     void *entry,
1409 			     enum event_trigger_type *tt)
1410 {
1411 	unsigned long eflags = file->flags;
1412 
1413 	if (eflags & EVENT_FILE_FL_TRIGGER_COND)
1414 		*tt = event_triggers_call(file, buffer, entry, event);
1415 
1416 	if (likely(!(file->flags & (EVENT_FILE_FL_SOFT_DISABLED |
1417 				    EVENT_FILE_FL_FILTERED |
1418 				    EVENT_FILE_FL_PID_FILTER))))
1419 		return false;
1420 
1421 	if (file->flags & EVENT_FILE_FL_SOFT_DISABLED)
1422 		goto discard;
1423 
1424 	if (file->flags & EVENT_FILE_FL_FILTERED &&
1425 	    !filter_match_preds(file->filter, entry))
1426 		goto discard;
1427 
1428 	if ((file->flags & EVENT_FILE_FL_PID_FILTER) &&
1429 	    trace_event_ignore_this_pid(file))
1430 		goto discard;
1431 
1432 	return false;
1433  discard:
1434 	__trace_event_discard_commit(buffer, event);
1435 	return true;
1436 }
1437 
1438 /**
1439  * event_trigger_unlock_commit - handle triggers and finish event commit
1440  * @file: The file pointer associated with the event
1441  * @buffer: The ring buffer that the event is being written to
1442  * @event: The event meta data in the ring buffer
1443  * @entry: The event itself
1444  * @trace_ctx: The tracing context flags.
1445  *
1446  * This is a helper function to handle triggers that require data
1447  * from the event itself. It also tests the event against filters and
1448  * if the event is soft disabled and should be discarded.
1449  */
1450 static inline void
1451 event_trigger_unlock_commit(struct trace_event_file *file,
1452 			    struct trace_buffer *buffer,
1453 			    struct ring_buffer_event *event,
1454 			    void *entry, unsigned int trace_ctx)
1455 {
1456 	enum event_trigger_type tt = ETT_NONE;
1457 
1458 	if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1459 		trace_buffer_unlock_commit(file->tr, buffer, event, trace_ctx);
1460 
1461 	if (tt)
1462 		event_triggers_post_call(file, tt);
1463 }
1464 
1465 #define FILTER_PRED_INVALID	((unsigned short)-1)
1466 #define FILTER_PRED_IS_RIGHT	(1 << 15)
1467 #define FILTER_PRED_FOLD	(1 << 15)
1468 
1469 /*
1470  * The max preds is the size of unsigned short with
1471  * two flags at the MSBs. One bit is used for both the IS_RIGHT
1472  * and FOLD flags. The other is reserved.
1473  *
1474  * 2^14 preds is way more than enough.
1475  */
1476 #define MAX_FILTER_PRED		16384
1477 
1478 struct filter_pred;
1479 struct regex;
1480 
1481 typedef int (*regex_match_func)(char *str, struct regex *r, int len);
1482 
1483 enum regex_type {
1484 	MATCH_FULL = 0,
1485 	MATCH_FRONT_ONLY,
1486 	MATCH_MIDDLE_ONLY,
1487 	MATCH_END_ONLY,
1488 	MATCH_GLOB,
1489 	MATCH_INDEX,
1490 };
1491 
1492 struct regex {
1493 	char			pattern[MAX_FILTER_STR_VAL];
1494 	int			len;
1495 	int			field_len;
1496 	regex_match_func	match;
1497 };
1498 
1499 static inline bool is_string_field(struct ftrace_event_field *field)
1500 {
1501 	return field->filter_type == FILTER_DYN_STRING ||
1502 	       field->filter_type == FILTER_RDYN_STRING ||
1503 	       field->filter_type == FILTER_STATIC_STRING ||
1504 	       field->filter_type == FILTER_PTR_STRING ||
1505 	       field->filter_type == FILTER_COMM;
1506 }
1507 
1508 static inline bool is_function_field(struct ftrace_event_field *field)
1509 {
1510 	return field->filter_type == FILTER_TRACE_FN;
1511 }
1512 
1513 extern enum regex_type
1514 filter_parse_regex(char *buff, int len, char **search, int *not);
1515 extern void print_event_filter(struct trace_event_file *file,
1516 			       struct trace_seq *s);
1517 extern int apply_event_filter(struct trace_event_file *file,
1518 			      char *filter_string);
1519 extern int apply_subsystem_event_filter(struct trace_subsystem_dir *dir,
1520 					char *filter_string);
1521 extern void print_subsystem_event_filter(struct event_subsystem *system,
1522 					 struct trace_seq *s);
1523 extern int filter_assign_type(const char *type);
1524 extern int create_event_filter(struct trace_array *tr,
1525 			       struct trace_event_call *call,
1526 			       char *filter_str, bool set_str,
1527 			       struct event_filter **filterp);
1528 extern void free_event_filter(struct event_filter *filter);
1529 
1530 struct ftrace_event_field *
1531 trace_find_event_field(struct trace_event_call *call, char *name);
1532 
1533 extern void trace_event_enable_cmd_record(bool enable);
1534 extern void trace_event_enable_tgid_record(bool enable);
1535 
1536 extern int event_trace_init(void);
1537 extern int init_events(void);
1538 extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
1539 extern int event_trace_del_tracer(struct trace_array *tr);
1540 extern void __trace_early_add_events(struct trace_array *tr);
1541 
1542 extern struct trace_event_file *__find_event_file(struct trace_array *tr,
1543 						  const char *system,
1544 						  const char *event);
1545 extern struct trace_event_file *find_event_file(struct trace_array *tr,
1546 						const char *system,
1547 						const char *event);
1548 
1549 static inline void *event_file_data(struct file *filp)
1550 {
1551 	return READ_ONCE(file_inode(filp)->i_private);
1552 }
1553 
1554 extern struct mutex event_mutex;
1555 extern struct list_head ftrace_events;
1556 
1557 extern const struct file_operations event_trigger_fops;
1558 extern const struct file_operations event_hist_fops;
1559 extern const struct file_operations event_hist_debug_fops;
1560 extern const struct file_operations event_inject_fops;
1561 
1562 #ifdef CONFIG_HIST_TRIGGERS
1563 extern int register_trigger_hist_cmd(void);
1564 extern int register_trigger_hist_enable_disable_cmds(void);
1565 #else
1566 static inline int register_trigger_hist_cmd(void) { return 0; }
1567 static inline int register_trigger_hist_enable_disable_cmds(void) { return 0; }
1568 #endif
1569 
1570 extern int register_trigger_cmds(void);
1571 extern void clear_event_triggers(struct trace_array *tr);
1572 
1573 enum {
1574 	EVENT_TRIGGER_FL_PROBE		= BIT(0),
1575 };
1576 
1577 struct event_trigger_data {
1578 	unsigned long			count;
1579 	int				ref;
1580 	int				flags;
1581 	struct event_trigger_ops	*ops;
1582 	struct event_command		*cmd_ops;
1583 	struct event_filter __rcu	*filter;
1584 	char				*filter_str;
1585 	void				*private_data;
1586 	bool				paused;
1587 	bool				paused_tmp;
1588 	struct list_head		list;
1589 	char				*name;
1590 	struct list_head		named_list;
1591 	struct event_trigger_data	*named_data;
1592 };
1593 
1594 /* Avoid typos */
1595 #define ENABLE_EVENT_STR	"enable_event"
1596 #define DISABLE_EVENT_STR	"disable_event"
1597 #define ENABLE_HIST_STR		"enable_hist"
1598 #define DISABLE_HIST_STR	"disable_hist"
1599 
1600 struct enable_trigger_data {
1601 	struct trace_event_file		*file;
1602 	bool				enable;
1603 	bool				hist;
1604 };
1605 
1606 extern int event_enable_trigger_print(struct seq_file *m,
1607 				      struct event_trigger_data *data);
1608 extern void event_enable_trigger_free(struct event_trigger_data *data);
1609 extern int event_enable_trigger_parse(struct event_command *cmd_ops,
1610 				      struct trace_event_file *file,
1611 				      char *glob, char *cmd,
1612 				      char *param_and_filter);
1613 extern int event_enable_register_trigger(char *glob,
1614 					 struct event_trigger_data *data,
1615 					 struct trace_event_file *file);
1616 extern void event_enable_unregister_trigger(char *glob,
1617 					    struct event_trigger_data *test,
1618 					    struct trace_event_file *file);
1619 extern void trigger_data_free(struct event_trigger_data *data);
1620 extern int event_trigger_init(struct event_trigger_data *data);
1621 extern int trace_event_trigger_enable_disable(struct trace_event_file *file,
1622 					      int trigger_enable);
1623 extern void update_cond_flag(struct trace_event_file *file);
1624 extern int set_trigger_filter(char *filter_str,
1625 			      struct event_trigger_data *trigger_data,
1626 			      struct trace_event_file *file);
1627 extern struct event_trigger_data *find_named_trigger(const char *name);
1628 extern bool is_named_trigger(struct event_trigger_data *test);
1629 extern int save_named_trigger(const char *name,
1630 			      struct event_trigger_data *data);
1631 extern void del_named_trigger(struct event_trigger_data *data);
1632 extern void pause_named_trigger(struct event_trigger_data *data);
1633 extern void unpause_named_trigger(struct event_trigger_data *data);
1634 extern void set_named_trigger_data(struct event_trigger_data *data,
1635 				   struct event_trigger_data *named_data);
1636 extern struct event_trigger_data *
1637 get_named_trigger_data(struct event_trigger_data *data);
1638 extern int register_event_command(struct event_command *cmd);
1639 extern int unregister_event_command(struct event_command *cmd);
1640 extern int register_trigger_hist_enable_disable_cmds(void);
1641 extern bool event_trigger_check_remove(const char *glob);
1642 extern bool event_trigger_empty_param(const char *param);
1643 extern int event_trigger_separate_filter(char *param_and_filter, char **param,
1644 					 char **filter, bool param_required);
1645 extern struct event_trigger_data *
1646 event_trigger_alloc(struct event_command *cmd_ops,
1647 		    char *cmd,
1648 		    char *param,
1649 		    void *private_data);
1650 extern int event_trigger_parse_num(char *trigger,
1651 				   struct event_trigger_data *trigger_data);
1652 extern int event_trigger_set_filter(struct event_command *cmd_ops,
1653 				    struct trace_event_file *file,
1654 				    char *param,
1655 				    struct event_trigger_data *trigger_data);
1656 extern void event_trigger_reset_filter(struct event_command *cmd_ops,
1657 				       struct event_trigger_data *trigger_data);
1658 extern int event_trigger_register(struct event_command *cmd_ops,
1659 				  struct trace_event_file *file,
1660 				  char *glob,
1661 				  struct event_trigger_data *trigger_data);
1662 extern void event_trigger_unregister(struct event_command *cmd_ops,
1663 				     struct trace_event_file *file,
1664 				     char *glob,
1665 				     struct event_trigger_data *trigger_data);
1666 
1667 /**
1668  * struct event_trigger_ops - callbacks for trace event triggers
1669  *
1670  * The methods in this structure provide per-event trigger hooks for
1671  * various trigger operations.
1672  *
1673  * The @init and @free methods are used during trigger setup and
1674  * teardown, typically called from an event_command's @parse()
1675  * function implementation.
1676  *
1677  * The @print method is used to print the trigger spec.
1678  *
1679  * The @trigger method is the function that actually implements the
1680  * trigger and is called in the context of the triggering event
1681  * whenever that event occurs.
1682  *
1683  * All the methods below, except for @init() and @free(), must be
1684  * implemented.
1685  *
1686  * @trigger: The trigger 'probe' function called when the triggering
1687  *	event occurs.  The data passed into this callback is the data
1688  *	that was supplied to the event_command @reg() function that
1689  *	registered the trigger (see struct event_command) along with
1690  *	the trace record, rec.
1691  *
1692  * @init: An optional initialization function called for the trigger
1693  *	when the trigger is registered (via the event_command reg()
1694  *	function).  This can be used to perform per-trigger
1695  *	initialization such as incrementing a per-trigger reference
1696  *	count, for instance.  This is usually implemented by the
1697  *	generic utility function @event_trigger_init() (see
1698  *	trace_event_triggers.c).
1699  *
1700  * @free: An optional de-initialization function called for the
1701  *	trigger when the trigger is unregistered (via the
1702  *	event_command @reg() function).  This can be used to perform
1703  *	per-trigger de-initialization such as decrementing a
1704  *	per-trigger reference count and freeing corresponding trigger
1705  *	data, for instance.  This is usually implemented by the
1706  *	generic utility function @event_trigger_free() (see
1707  *	trace_event_triggers.c).
1708  *
1709  * @print: The callback function invoked to have the trigger print
1710  *	itself.  This is usually implemented by a wrapper function
1711  *	that calls the generic utility function @event_trigger_print()
1712  *	(see trace_event_triggers.c).
1713  */
1714 struct event_trigger_ops {
1715 	void			(*trigger)(struct event_trigger_data *data,
1716 					   struct trace_buffer *buffer,
1717 					   void *rec,
1718 					   struct ring_buffer_event *rbe);
1719 	int			(*init)(struct event_trigger_data *data);
1720 	void			(*free)(struct event_trigger_data *data);
1721 	int			(*print)(struct seq_file *m,
1722 					 struct event_trigger_data *data);
1723 };
1724 
1725 /**
1726  * struct event_command - callbacks and data members for event commands
1727  *
1728  * Event commands are invoked by users by writing the command name
1729  * into the 'trigger' file associated with a trace event.  The
1730  * parameters associated with a specific invocation of an event
1731  * command are used to create an event trigger instance, which is
1732  * added to the list of trigger instances associated with that trace
1733  * event.  When the event is hit, the set of triggers associated with
1734  * that event is invoked.
1735  *
1736  * The data members in this structure provide per-event command data
1737  * for various event commands.
1738  *
1739  * All the data members below, except for @post_trigger, must be set
1740  * for each event command.
1741  *
1742  * @name: The unique name that identifies the event command.  This is
1743  *	the name used when setting triggers via trigger files.
1744  *
1745  * @trigger_type: A unique id that identifies the event command
1746  *	'type'.  This value has two purposes, the first to ensure that
1747  *	only one trigger of the same type can be set at a given time
1748  *	for a particular event e.g. it doesn't make sense to have both
1749  *	a traceon and traceoff trigger attached to a single event at
1750  *	the same time, so traceon and traceoff have the same type
1751  *	though they have different names.  The @trigger_type value is
1752  *	also used as a bit value for deferring the actual trigger
1753  *	action until after the current event is finished.  Some
1754  *	commands need to do this if they themselves log to the trace
1755  *	buffer (see the @post_trigger() member below).  @trigger_type
1756  *	values are defined by adding new values to the trigger_type
1757  *	enum in include/linux/trace_events.h.
1758  *
1759  * @flags: See the enum event_command_flags below.
1760  *
1761  * All the methods below, except for @set_filter() and @unreg_all(),
1762  * must be implemented.
1763  *
1764  * @parse: The callback function responsible for parsing and
1765  *	registering the trigger written to the 'trigger' file by the
1766  *	user.  It allocates the trigger instance and registers it with
1767  *	the appropriate trace event.  It makes use of the other
1768  *	event_command callback functions to orchestrate this, and is
1769  *	usually implemented by the generic utility function
1770  *	@event_trigger_callback() (see trace_event_triggers.c).
1771  *
1772  * @reg: Adds the trigger to the list of triggers associated with the
1773  *	event, and enables the event trigger itself, after
1774  *	initializing it (via the event_trigger_ops @init() function).
1775  *	This is also where commands can use the @trigger_type value to
1776  *	make the decision as to whether or not multiple instances of
1777  *	the trigger should be allowed.  This is usually implemented by
1778  *	the generic utility function @register_trigger() (see
1779  *	trace_event_triggers.c).
1780  *
1781  * @unreg: Removes the trigger from the list of triggers associated
1782  *	with the event, and disables the event trigger itself, after
1783  *	initializing it (via the event_trigger_ops @free() function).
1784  *	This is usually implemented by the generic utility function
1785  *	@unregister_trigger() (see trace_event_triggers.c).
1786  *
1787  * @unreg_all: An optional function called to remove all the triggers
1788  *	from the list of triggers associated with the event.  Called
1789  *	when a trigger file is opened in truncate mode.
1790  *
1791  * @set_filter: An optional function called to parse and set a filter
1792  *	for the trigger.  If no @set_filter() method is set for the
1793  *	event command, filters set by the user for the command will be
1794  *	ignored.  This is usually implemented by the generic utility
1795  *	function @set_trigger_filter() (see trace_event_triggers.c).
1796  *
1797  * @get_trigger_ops: The callback function invoked to retrieve the
1798  *	event_trigger_ops implementation associated with the command.
1799  *	This callback function allows a single event_command to
1800  *	support multiple trigger implementations via different sets of
1801  *	event_trigger_ops, depending on the value of the @param
1802  *	string.
1803  */
1804 struct event_command {
1805 	struct list_head	list;
1806 	char			*name;
1807 	enum event_trigger_type	trigger_type;
1808 	int			flags;
1809 	int			(*parse)(struct event_command *cmd_ops,
1810 					 struct trace_event_file *file,
1811 					 char *glob, char *cmd,
1812 					 char *param_and_filter);
1813 	int			(*reg)(char *glob,
1814 				       struct event_trigger_data *data,
1815 				       struct trace_event_file *file);
1816 	void			(*unreg)(char *glob,
1817 					 struct event_trigger_data *data,
1818 					 struct trace_event_file *file);
1819 	void			(*unreg_all)(struct trace_event_file *file);
1820 	int			(*set_filter)(char *filter_str,
1821 					      struct event_trigger_data *data,
1822 					      struct trace_event_file *file);
1823 	struct event_trigger_ops *(*get_trigger_ops)(char *cmd, char *param);
1824 };
1825 
1826 /**
1827  * enum event_command_flags - flags for struct event_command
1828  *
1829  * @POST_TRIGGER: A flag that says whether or not this command needs
1830  *	to have its action delayed until after the current event has
1831  *	been closed.  Some triggers need to avoid being invoked while
1832  *	an event is currently in the process of being logged, since
1833  *	the trigger may itself log data into the trace buffer.  Thus
1834  *	we make sure the current event is committed before invoking
1835  *	those triggers.  To do that, the trigger invocation is split
1836  *	in two - the first part checks the filter using the current
1837  *	trace record; if a command has the @post_trigger flag set, it
1838  *	sets a bit for itself in the return value, otherwise it
1839  *	directly invokes the trigger.  Once all commands have been
1840  *	either invoked or set their return flag, the current record is
1841  *	either committed or discarded.  At that point, if any commands
1842  *	have deferred their triggers, those commands are finally
1843  *	invoked following the close of the current event.  In other
1844  *	words, if the event_trigger_ops @func() probe implementation
1845  *	itself logs to the trace buffer, this flag should be set,
1846  *	otherwise it can be left unspecified.
1847  *
1848  * @NEEDS_REC: A flag that says whether or not this command needs
1849  *	access to the trace record in order to perform its function,
1850  *	regardless of whether or not it has a filter associated with
1851  *	it (filters make a trigger require access to the trace record
1852  *	but are not always present).
1853  */
1854 enum event_command_flags {
1855 	EVENT_CMD_FL_POST_TRIGGER	= 1,
1856 	EVENT_CMD_FL_NEEDS_REC		= 2,
1857 };
1858 
1859 static inline bool event_command_post_trigger(struct event_command *cmd_ops)
1860 {
1861 	return cmd_ops->flags & EVENT_CMD_FL_POST_TRIGGER;
1862 }
1863 
1864 static inline bool event_command_needs_rec(struct event_command *cmd_ops)
1865 {
1866 	return cmd_ops->flags & EVENT_CMD_FL_NEEDS_REC;
1867 }
1868 
1869 extern int trace_event_enable_disable(struct trace_event_file *file,
1870 				      int enable, int soft_disable);
1871 extern int tracing_alloc_snapshot(void);
1872 extern void tracing_snapshot_cond(struct trace_array *tr, void *cond_data);
1873 extern int tracing_snapshot_cond_enable(struct trace_array *tr, void *cond_data, cond_update_fn_t update);
1874 
1875 extern int tracing_snapshot_cond_disable(struct trace_array *tr);
1876 extern void *tracing_cond_snapshot_data(struct trace_array *tr);
1877 
1878 extern const char *__start___trace_bprintk_fmt[];
1879 extern const char *__stop___trace_bprintk_fmt[];
1880 
1881 extern const char *__start___tracepoint_str[];
1882 extern const char *__stop___tracepoint_str[];
1883 
1884 void trace_printk_control(bool enabled);
1885 void trace_printk_start_comm(void);
1886 int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set);
1887 int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled);
1888 
1889 /* Used from boot time tracer */
1890 extern int trace_set_options(struct trace_array *tr, char *option);
1891 extern int tracing_set_tracer(struct trace_array *tr, const char *buf);
1892 extern ssize_t tracing_resize_ring_buffer(struct trace_array *tr,
1893 					  unsigned long size, int cpu_id);
1894 extern int tracing_set_cpumask(struct trace_array *tr,
1895 				cpumask_var_t tracing_cpumask_new);
1896 
1897 
1898 #define MAX_EVENT_NAME_LEN	64
1899 
1900 extern ssize_t trace_parse_run_command(struct file *file,
1901 		const char __user *buffer, size_t count, loff_t *ppos,
1902 		int (*createfn)(const char *));
1903 
1904 extern unsigned int err_pos(char *cmd, const char *str);
1905 extern void tracing_log_err(struct trace_array *tr,
1906 			    const char *loc, const char *cmd,
1907 			    const char **errs, u8 type, u16 pos);
1908 
1909 /*
1910  * Normal trace_printk() and friends allocates special buffers
1911  * to do the manipulation, as well as saves the print formats
1912  * into sections to display. But the trace infrastructure wants
1913  * to use these without the added overhead at the price of being
1914  * a bit slower (used mainly for warnings, where we don't care
1915  * about performance). The internal_trace_puts() is for such
1916  * a purpose.
1917  */
1918 #define internal_trace_puts(str) __trace_puts(_THIS_IP_, str, strlen(str))
1919 
1920 #undef FTRACE_ENTRY
1921 #define FTRACE_ENTRY(call, struct_name, id, tstruct, print)	\
1922 	extern struct trace_event_call					\
1923 	__aligned(4) event_##call;
1924 #undef FTRACE_ENTRY_DUP
1925 #define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print)	\
1926 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
1927 #undef FTRACE_ENTRY_PACKED
1928 #define FTRACE_ENTRY_PACKED(call, struct_name, id, tstruct, print) \
1929 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
1930 
1931 #include "trace_entries.h"
1932 
1933 #if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_FUNCTION_TRACER)
1934 int perf_ftrace_event_register(struct trace_event_call *call,
1935 			       enum trace_reg type, void *data);
1936 #else
1937 #define perf_ftrace_event_register NULL
1938 #endif
1939 
1940 #ifdef CONFIG_FTRACE_SYSCALLS
1941 void init_ftrace_syscalls(void);
1942 const char *get_syscall_name(int syscall);
1943 #else
1944 static inline void init_ftrace_syscalls(void) { }
1945 static inline const char *get_syscall_name(int syscall)
1946 {
1947 	return NULL;
1948 }
1949 #endif
1950 
1951 #ifdef CONFIG_EVENT_TRACING
1952 void trace_event_init(void);
1953 void trace_event_eval_update(struct trace_eval_map **map, int len);
1954 /* Used from boot time tracer */
1955 extern int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set);
1956 extern int trigger_process_regex(struct trace_event_file *file, char *buff);
1957 #else
1958 static inline void __init trace_event_init(void) { }
1959 static inline void trace_event_eval_update(struct trace_eval_map **map, int len) { }
1960 #endif
1961 
1962 #ifdef CONFIG_TRACER_SNAPSHOT
1963 void tracing_snapshot_instance(struct trace_array *tr);
1964 int tracing_alloc_snapshot_instance(struct trace_array *tr);
1965 #else
1966 static inline void tracing_snapshot_instance(struct trace_array *tr) { }
1967 static inline int tracing_alloc_snapshot_instance(struct trace_array *tr)
1968 {
1969 	return 0;
1970 }
1971 #endif
1972 
1973 #ifdef CONFIG_PREEMPT_TRACER
1974 void tracer_preempt_on(unsigned long a0, unsigned long a1);
1975 void tracer_preempt_off(unsigned long a0, unsigned long a1);
1976 #else
1977 static inline void tracer_preempt_on(unsigned long a0, unsigned long a1) { }
1978 static inline void tracer_preempt_off(unsigned long a0, unsigned long a1) { }
1979 #endif
1980 #ifdef CONFIG_IRQSOFF_TRACER
1981 void tracer_hardirqs_on(unsigned long a0, unsigned long a1);
1982 void tracer_hardirqs_off(unsigned long a0, unsigned long a1);
1983 #else
1984 static inline void tracer_hardirqs_on(unsigned long a0, unsigned long a1) { }
1985 static inline void tracer_hardirqs_off(unsigned long a0, unsigned long a1) { }
1986 #endif
1987 
1988 /*
1989  * Reset the state of the trace_iterator so that it can read consumed data.
1990  * Normally, the trace_iterator is used for reading the data when it is not
1991  * consumed, and must retain state.
1992  */
1993 static __always_inline void trace_iterator_reset(struct trace_iterator *iter)
1994 {
1995 	memset_startat(iter, 0, seq);
1996 	iter->pos = -1;
1997 }
1998 
1999 /* Check the name is good for event/group/fields */
2000 static inline bool __is_good_name(const char *name, bool hash_ok)
2001 {
2002 	if (!isalpha(*name) && *name != '_' && (!hash_ok || *name != '-'))
2003 		return false;
2004 	while (*++name != '\0') {
2005 		if (!isalpha(*name) && !isdigit(*name) && *name != '_' &&
2006 		    (!hash_ok || *name != '-'))
2007 			return false;
2008 	}
2009 	return true;
2010 }
2011 
2012 /* Check the name is good for event/group/fields */
2013 static inline bool is_good_name(const char *name)
2014 {
2015 	return __is_good_name(name, false);
2016 }
2017 
2018 /* Check the name is good for system */
2019 static inline bool is_good_system_name(const char *name)
2020 {
2021 	return __is_good_name(name, true);
2022 }
2023 
2024 /* Convert certain expected symbols into '_' when generating event names */
2025 static inline void sanitize_event_name(char *name)
2026 {
2027 	while (*name++ != '\0')
2028 		if (*name == ':' || *name == '.')
2029 			*name = '_';
2030 }
2031 
2032 /*
2033  * This is a generic way to read and write a u64 value from a file in tracefs.
2034  *
2035  * The value is stored on the variable pointed by *val. The value needs
2036  * to be at least *min and at most *max. The write is protected by an
2037  * existing *lock.
2038  */
2039 struct trace_min_max_param {
2040 	struct mutex	*lock;
2041 	u64		*val;
2042 	u64		*min;
2043 	u64		*max;
2044 };
2045 
2046 #define U64_STR_SIZE		24	/* 20 digits max */
2047 
2048 extern const struct file_operations trace_min_max_fops;
2049 
2050 #ifdef CONFIG_RV
2051 extern int rv_init_interface(void);
2052 #else
2053 static inline int rv_init_interface(void)
2054 {
2055 	return 0;
2056 }
2057 #endif
2058 
2059 #endif /* _LINUX_KERNEL_TRACE_H */
2060