xref: /linux/kernel/trace/trace.h (revision 6efc0ab3b05de0d7bab8ec0597214e4788251071)
1 // SPDX-License-Identifier: GPL-2.0
2 
3 #ifndef _LINUX_KERNEL_TRACE_H
4 #define _LINUX_KERNEL_TRACE_H
5 
6 #include <linux/fs.h>
7 #include <linux/atomic.h>
8 #include <linux/sched.h>
9 #include <linux/clocksource.h>
10 #include <linux/ring_buffer.h>
11 #include <linux/mmiotrace.h>
12 #include <linux/tracepoint.h>
13 #include <linux/ftrace.h>
14 #include <linux/trace.h>
15 #include <linux/hw_breakpoint.h>
16 #include <linux/trace_seq.h>
17 #include <linux/trace_events.h>
18 #include <linux/compiler.h>
19 #include <linux/glob.h>
20 #include <linux/irq_work.h>
21 #include <linux/workqueue.h>
22 #include <linux/ctype.h>
23 #include <linux/once_lite.h>
24 
25 #include "pid_list.h"
26 
27 #ifdef CONFIG_FTRACE_SYSCALLS
28 #include <asm/unistd.h>		/* For NR_syscalls	     */
29 #include <asm/syscall.h>	/* some archs define it here */
30 #endif
31 
32 #define TRACE_MODE_WRITE	0640
33 #define TRACE_MODE_READ		0440
34 
35 enum trace_type {
36 	__TRACE_FIRST_TYPE = 0,
37 
38 	TRACE_FN,
39 	TRACE_CTX,
40 	TRACE_WAKE,
41 	TRACE_STACK,
42 	TRACE_PRINT,
43 	TRACE_BPRINT,
44 	TRACE_MMIO_RW,
45 	TRACE_MMIO_MAP,
46 	TRACE_BRANCH,
47 	TRACE_GRAPH_RET,
48 	TRACE_GRAPH_ENT,
49 	TRACE_USER_STACK,
50 	TRACE_BLK,
51 	TRACE_BPUTS,
52 	TRACE_HWLAT,
53 	TRACE_OSNOISE,
54 	TRACE_TIMERLAT,
55 	TRACE_RAW_DATA,
56 	TRACE_FUNC_REPEATS,
57 
58 	__TRACE_LAST_TYPE,
59 };
60 
61 
62 #undef __field
63 #define __field(type, item)		type	item;
64 
65 #undef __field_fn
66 #define __field_fn(type, item)		type	item;
67 
68 #undef __field_struct
69 #define __field_struct(type, item)	__field(type, item)
70 
71 #undef __field_desc
72 #define __field_desc(type, container, item)
73 
74 #undef __field_packed
75 #define __field_packed(type, container, item)
76 
77 #undef __array
78 #define __array(type, item, size)	type	item[size];
79 
80 /*
81  * For backward compatibility, older user space expects to see the
82  * kernel_stack event with a fixed size caller field. But today the fix
83  * size is ignored by the kernel, and the real structure is dynamic.
84  * Expose to user space: "unsigned long caller[8];" but the real structure
85  * will be "unsigned long caller[] __counted_by(size)"
86  */
87 #undef __stack_array
88 #define __stack_array(type, item, size, field)		type item[] __counted_by(field);
89 
90 #undef __array_desc
91 #define __array_desc(type, container, item, size)
92 
93 #undef __dynamic_array
94 #define __dynamic_array(type, item)	type	item[];
95 
96 #undef __rel_dynamic_array
97 #define __rel_dynamic_array(type, item)	type	item[];
98 
99 #undef F_STRUCT
100 #define F_STRUCT(args...)		args
101 
102 #undef FTRACE_ENTRY
103 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print)		\
104 	struct struct_name {						\
105 		struct trace_entry	ent;				\
106 		tstruct							\
107 	}
108 
109 #undef FTRACE_ENTRY_DUP
110 #define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk)
111 
112 #undef FTRACE_ENTRY_REG
113 #define FTRACE_ENTRY_REG(name, struct_name, id, tstruct, print,	regfn)	\
114 	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print))
115 
116 #undef FTRACE_ENTRY_PACKED
117 #define FTRACE_ENTRY_PACKED(name, struct_name, id, tstruct, print)	\
118 	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print)) __packed
119 
120 #include "trace_entries.h"
121 
122 /* Use this for memory failure errors */
123 #define MEM_FAIL(condition, fmt, ...)					\
124 	DO_ONCE_LITE_IF(condition, pr_err, "ERROR: " fmt, ##__VA_ARGS__)
125 
126 #define FAULT_STRING "(fault)"
127 
128 #define HIST_STACKTRACE_DEPTH	16
129 #define HIST_STACKTRACE_SIZE	(HIST_STACKTRACE_DEPTH * sizeof(unsigned long))
130 #define HIST_STACKTRACE_SKIP	5
131 
132 /*
133  * syscalls are special, and need special handling, this is why
134  * they are not included in trace_entries.h
135  */
136 struct syscall_trace_enter {
137 	struct trace_entry	ent;
138 	int			nr;
139 	unsigned long		args[];
140 };
141 
142 struct syscall_trace_exit {
143 	struct trace_entry	ent;
144 	int			nr;
145 	long			ret;
146 };
147 
148 struct kprobe_trace_entry_head {
149 	struct trace_entry	ent;
150 	unsigned long		ip;
151 };
152 
153 struct eprobe_trace_entry_head {
154 	struct trace_entry	ent;
155 };
156 
157 struct kretprobe_trace_entry_head {
158 	struct trace_entry	ent;
159 	unsigned long		func;
160 	unsigned long		ret_ip;
161 };
162 
163 struct fentry_trace_entry_head {
164 	struct trace_entry	ent;
165 	unsigned long		ip;
166 };
167 
168 struct fexit_trace_entry_head {
169 	struct trace_entry	ent;
170 	unsigned long		func;
171 	unsigned long		ret_ip;
172 };
173 
174 #define TRACE_BUF_SIZE		1024
175 
176 struct trace_array;
177 
178 /*
179  * The CPU trace array - it consists of thousands of trace entries
180  * plus some other descriptor data: (for example which task started
181  * the trace, etc.)
182  */
183 struct trace_array_cpu {
184 	atomic_t		disabled;
185 	void			*buffer_page;	/* ring buffer spare */
186 
187 	unsigned long		entries;
188 	unsigned long		saved_latency;
189 	unsigned long		critical_start;
190 	unsigned long		critical_end;
191 	unsigned long		critical_sequence;
192 	unsigned long		nice;
193 	unsigned long		policy;
194 	unsigned long		rt_priority;
195 	unsigned long		skipped_entries;
196 	u64			preempt_timestamp;
197 	pid_t			pid;
198 	kuid_t			uid;
199 	char			comm[TASK_COMM_LEN];
200 
201 #ifdef CONFIG_FUNCTION_TRACER
202 	int			ftrace_ignore_pid;
203 #endif
204 	bool			ignore_pid;
205 };
206 
207 struct tracer;
208 struct trace_option_dentry;
209 
210 struct array_buffer {
211 	struct trace_array		*tr;
212 	struct trace_buffer		*buffer;
213 	struct trace_array_cpu __percpu	*data;
214 	u64				time_start;
215 	int				cpu;
216 };
217 
218 #define TRACE_FLAGS_MAX_SIZE		32
219 
220 struct trace_options {
221 	struct tracer			*tracer;
222 	struct trace_option_dentry	*topts;
223 };
224 
225 struct trace_pid_list *trace_pid_list_alloc(void);
226 void trace_pid_list_free(struct trace_pid_list *pid_list);
227 bool trace_pid_list_is_set(struct trace_pid_list *pid_list, unsigned int pid);
228 int trace_pid_list_set(struct trace_pid_list *pid_list, unsigned int pid);
229 int trace_pid_list_clear(struct trace_pid_list *pid_list, unsigned int pid);
230 int trace_pid_list_first(struct trace_pid_list *pid_list, unsigned int *pid);
231 int trace_pid_list_next(struct trace_pid_list *pid_list, unsigned int pid,
232 			unsigned int *next);
233 
234 enum {
235 	TRACE_PIDS		= BIT(0),
236 	TRACE_NO_PIDS		= BIT(1),
237 };
238 
239 static inline bool pid_type_enabled(int type, struct trace_pid_list *pid_list,
240 				    struct trace_pid_list *no_pid_list)
241 {
242 	/* Return true if the pid list in type has pids */
243 	return ((type & TRACE_PIDS) && pid_list) ||
244 		((type & TRACE_NO_PIDS) && no_pid_list);
245 }
246 
247 static inline bool still_need_pid_events(int type, struct trace_pid_list *pid_list,
248 					 struct trace_pid_list *no_pid_list)
249 {
250 	/*
251 	 * Turning off what is in @type, return true if the "other"
252 	 * pid list, still has pids in it.
253 	 */
254 	return (!(type & TRACE_PIDS) && pid_list) ||
255 		(!(type & TRACE_NO_PIDS) && no_pid_list);
256 }
257 
258 typedef bool (*cond_update_fn_t)(struct trace_array *tr, void *cond_data);
259 
260 /**
261  * struct cond_snapshot - conditional snapshot data and callback
262  *
263  * The cond_snapshot structure encapsulates a callback function and
264  * data associated with the snapshot for a given tracing instance.
265  *
266  * When a snapshot is taken conditionally, by invoking
267  * tracing_snapshot_cond(tr, cond_data), the cond_data passed in is
268  * passed in turn to the cond_snapshot.update() function.  That data
269  * can be compared by the update() implementation with the cond_data
270  * contained within the struct cond_snapshot instance associated with
271  * the trace_array.  Because the tr->max_lock is held throughout the
272  * update() call, the update() function can directly retrieve the
273  * cond_snapshot and cond_data associated with the per-instance
274  * snapshot associated with the trace_array.
275  *
276  * The cond_snapshot.update() implementation can save data to be
277  * associated with the snapshot if it decides to, and returns 'true'
278  * in that case, or it returns 'false' if the conditional snapshot
279  * shouldn't be taken.
280  *
281  * The cond_snapshot instance is created and associated with the
282  * user-defined cond_data by tracing_cond_snapshot_enable().
283  * Likewise, the cond_snapshot instance is destroyed and is no longer
284  * associated with the trace instance by
285  * tracing_cond_snapshot_disable().
286  *
287  * The method below is required.
288  *
289  * @update: When a conditional snapshot is invoked, the update()
290  *	callback function is invoked with the tr->max_lock held.  The
291  *	update() implementation signals whether or not to actually
292  *	take the snapshot, by returning 'true' if so, 'false' if no
293  *	snapshot should be taken.  Because the max_lock is held for
294  *	the duration of update(), the implementation is safe to
295  *	directly retrieved and save any implementation data it needs
296  *	to in association with the snapshot.
297  */
298 struct cond_snapshot {
299 	void				*cond_data;
300 	cond_update_fn_t		update;
301 };
302 
303 /*
304  * struct trace_func_repeats - used to keep track of the consecutive
305  * (on the same CPU) calls of a single function.
306  */
307 struct trace_func_repeats {
308 	unsigned long	ip;
309 	unsigned long	parent_ip;
310 	unsigned long	count;
311 	u64		ts_last_call;
312 };
313 
314 /*
315  * The trace array - an array of per-CPU trace arrays. This is the
316  * highest level data structure that individual tracers deal with.
317  * They have on/off state as well:
318  */
319 struct trace_array {
320 	struct list_head	list;
321 	char			*name;
322 	struct array_buffer	array_buffer;
323 #ifdef CONFIG_TRACER_MAX_TRACE
324 	/*
325 	 * The max_buffer is used to snapshot the trace when a maximum
326 	 * latency is reached, or when the user initiates a snapshot.
327 	 * Some tracers will use this to store a maximum trace while
328 	 * it continues examining live traces.
329 	 *
330 	 * The buffers for the max_buffer are set up the same as the array_buffer
331 	 * When a snapshot is taken, the buffer of the max_buffer is swapped
332 	 * with the buffer of the array_buffer and the buffers are reset for
333 	 * the array_buffer so the tracing can continue.
334 	 */
335 	struct array_buffer	max_buffer;
336 	bool			allocated_snapshot;
337 	spinlock_t		snapshot_trigger_lock;
338 	unsigned int		snapshot;
339 	unsigned int		mapped;
340 	unsigned long		max_latency;
341 #ifdef CONFIG_FSNOTIFY
342 	struct dentry		*d_max_latency;
343 	struct work_struct	fsnotify_work;
344 	struct irq_work		fsnotify_irqwork;
345 #endif
346 #endif
347 	struct trace_pid_list	__rcu *filtered_pids;
348 	struct trace_pid_list	__rcu *filtered_no_pids;
349 	/*
350 	 * max_lock is used to protect the swapping of buffers
351 	 * when taking a max snapshot. The buffers themselves are
352 	 * protected by per_cpu spinlocks. But the action of the swap
353 	 * needs its own lock.
354 	 *
355 	 * This is defined as a arch_spinlock_t in order to help
356 	 * with performance when lockdep debugging is enabled.
357 	 *
358 	 * It is also used in other places outside the update_max_tr
359 	 * so it needs to be defined outside of the
360 	 * CONFIG_TRACER_MAX_TRACE.
361 	 */
362 	arch_spinlock_t		max_lock;
363 	int			buffer_disabled;
364 #ifdef CONFIG_FTRACE_SYSCALLS
365 	int			sys_refcount_enter;
366 	int			sys_refcount_exit;
367 	struct trace_event_file __rcu *enter_syscall_files[NR_syscalls];
368 	struct trace_event_file __rcu *exit_syscall_files[NR_syscalls];
369 #endif
370 	int			stop_count;
371 	int			clock_id;
372 	int			nr_topts;
373 	bool			clear_trace;
374 	int			buffer_percent;
375 	unsigned int		n_err_log_entries;
376 	struct tracer		*current_trace;
377 	unsigned int		trace_flags;
378 	unsigned char		trace_flags_index[TRACE_FLAGS_MAX_SIZE];
379 	unsigned int		flags;
380 	raw_spinlock_t		start_lock;
381 	const char		*system_names;
382 	struct list_head	err_log;
383 	struct dentry		*dir;
384 	struct dentry		*options;
385 	struct dentry		*percpu_dir;
386 	struct eventfs_inode	*event_dir;
387 	struct trace_options	*topts;
388 	struct list_head	systems;
389 	struct list_head	events;
390 	struct trace_event_file *trace_marker_file;
391 	cpumask_var_t		tracing_cpumask; /* only trace on set CPUs */
392 	/* one per_cpu trace_pipe can be opened by only one user */
393 	cpumask_var_t		pipe_cpumask;
394 	int			ref;
395 	int			trace_ref;
396 #ifdef CONFIG_FUNCTION_TRACER
397 	struct ftrace_ops	*ops;
398 	struct trace_pid_list	__rcu *function_pids;
399 	struct trace_pid_list	__rcu *function_no_pids;
400 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
401 	struct fgraph_ops	*gops;
402 #endif
403 #ifdef CONFIG_DYNAMIC_FTRACE
404 	/* All of these are protected by the ftrace_lock */
405 	struct list_head	func_probes;
406 	struct list_head	mod_trace;
407 	struct list_head	mod_notrace;
408 #endif
409 	/* function tracing enabled */
410 	int			function_enabled;
411 #endif
412 	int			no_filter_buffering_ref;
413 	struct list_head	hist_vars;
414 #ifdef CONFIG_TRACER_SNAPSHOT
415 	struct cond_snapshot	*cond_snapshot;
416 #endif
417 	struct trace_func_repeats	__percpu *last_func_repeats;
418 	/*
419 	 * On boot up, the ring buffer is set to the minimum size, so that
420 	 * we do not waste memory on systems that are not using tracing.
421 	 */
422 	bool ring_buffer_expanded;
423 };
424 
425 enum {
426 	TRACE_ARRAY_FL_GLOBAL	= (1 << 0)
427 };
428 
429 extern struct list_head ftrace_trace_arrays;
430 
431 extern struct mutex trace_types_lock;
432 
433 extern int trace_array_get(struct trace_array *tr);
434 extern int tracing_check_open_get_tr(struct trace_array *tr);
435 extern struct trace_array *trace_array_find(const char *instance);
436 extern struct trace_array *trace_array_find_get(const char *instance);
437 
438 extern u64 tracing_event_time_stamp(struct trace_buffer *buffer, struct ring_buffer_event *rbe);
439 extern int tracing_set_filter_buffering(struct trace_array *tr, bool set);
440 extern int tracing_set_clock(struct trace_array *tr, const char *clockstr);
441 
442 extern bool trace_clock_in_ns(struct trace_array *tr);
443 
444 /*
445  * The global tracer (top) should be the first trace array added,
446  * but we check the flag anyway.
447  */
448 static inline struct trace_array *top_trace_array(void)
449 {
450 	struct trace_array *tr;
451 
452 	if (list_empty(&ftrace_trace_arrays))
453 		return NULL;
454 
455 	tr = list_entry(ftrace_trace_arrays.prev,
456 			typeof(*tr), list);
457 	WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
458 	return tr;
459 }
460 
461 #define FTRACE_CMP_TYPE(var, type) \
462 	__builtin_types_compatible_p(typeof(var), type *)
463 
464 #undef IF_ASSIGN
465 #define IF_ASSIGN(var, entry, etype, id)			\
466 	if (FTRACE_CMP_TYPE(var, etype)) {			\
467 		var = (typeof(var))(entry);			\
468 		WARN_ON(id != 0 && (entry)->type != id);	\
469 		break;						\
470 	}
471 
472 /* Will cause compile errors if type is not found. */
473 extern void __ftrace_bad_type(void);
474 
475 /*
476  * The trace_assign_type is a verifier that the entry type is
477  * the same as the type being assigned. To add new types simply
478  * add a line with the following format:
479  *
480  * IF_ASSIGN(var, ent, type, id);
481  *
482  *  Where "type" is the trace type that includes the trace_entry
483  *  as the "ent" item. And "id" is the trace identifier that is
484  *  used in the trace_type enum.
485  *
486  *  If the type can have more than one id, then use zero.
487  */
488 #define trace_assign_type(var, ent)					\
489 	do {								\
490 		IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);	\
491 		IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);	\
492 		IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);	\
493 		IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
494 		IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);	\
495 		IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT);	\
496 		IF_ASSIGN(var, ent, struct bputs_entry, TRACE_BPUTS);	\
497 		IF_ASSIGN(var, ent, struct hwlat_entry, TRACE_HWLAT);	\
498 		IF_ASSIGN(var, ent, struct osnoise_entry, TRACE_OSNOISE);\
499 		IF_ASSIGN(var, ent, struct timerlat_entry, TRACE_TIMERLAT);\
500 		IF_ASSIGN(var, ent, struct raw_data_entry, TRACE_RAW_DATA);\
501 		IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,		\
502 			  TRACE_MMIO_RW);				\
503 		IF_ASSIGN(var, ent, struct trace_mmiotrace_map,		\
504 			  TRACE_MMIO_MAP);				\
505 		IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
506 		IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,	\
507 			  TRACE_GRAPH_ENT);		\
508 		IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,	\
509 			  TRACE_GRAPH_RET);		\
510 		IF_ASSIGN(var, ent, struct func_repeats_entry,		\
511 			  TRACE_FUNC_REPEATS);				\
512 		__ftrace_bad_type();					\
513 	} while (0)
514 
515 /*
516  * An option specific to a tracer. This is a boolean value.
517  * The bit is the bit index that sets its value on the
518  * flags value in struct tracer_flags.
519  */
520 struct tracer_opt {
521 	const char	*name; /* Will appear on the trace_options file */
522 	u32		bit; /* Mask assigned in val field in tracer_flags */
523 };
524 
525 /*
526  * The set of specific options for a tracer. Your tracer
527  * have to set the initial value of the flags val.
528  */
529 struct tracer_flags {
530 	u32			val;
531 	struct tracer_opt	*opts;
532 	struct tracer		*trace;
533 };
534 
535 /* Makes more easy to define a tracer opt */
536 #define TRACER_OPT(s, b)	.name = #s, .bit = b
537 
538 
539 struct trace_option_dentry {
540 	struct tracer_opt		*opt;
541 	struct tracer_flags		*flags;
542 	struct trace_array		*tr;
543 	struct dentry			*entry;
544 };
545 
546 /**
547  * struct tracer - a specific tracer and its callbacks to interact with tracefs
548  * @name: the name chosen to select it on the available_tracers file
549  * @init: called when one switches to this tracer (echo name > current_tracer)
550  * @reset: called when one switches to another tracer
551  * @start: called when tracing is unpaused (echo 1 > tracing_on)
552  * @stop: called when tracing is paused (echo 0 > tracing_on)
553  * @update_thresh: called when tracing_thresh is updated
554  * @open: called when the trace file is opened
555  * @pipe_open: called when the trace_pipe file is opened
556  * @close: called when the trace file is released
557  * @pipe_close: called when the trace_pipe file is released
558  * @read: override the default read callback on trace_pipe
559  * @splice_read: override the default splice_read callback on trace_pipe
560  * @selftest: selftest to run on boot (see trace_selftest.c)
561  * @print_headers: override the first lines that describe your columns
562  * @print_line: callback that prints a trace
563  * @set_flag: signals one of your private flags changed (trace_options file)
564  * @flags: your private flags
565  */
566 struct tracer {
567 	const char		*name;
568 	int			(*init)(struct trace_array *tr);
569 	void			(*reset)(struct trace_array *tr);
570 	void			(*start)(struct trace_array *tr);
571 	void			(*stop)(struct trace_array *tr);
572 	int			(*update_thresh)(struct trace_array *tr);
573 	void			(*open)(struct trace_iterator *iter);
574 	void			(*pipe_open)(struct trace_iterator *iter);
575 	void			(*close)(struct trace_iterator *iter);
576 	void			(*pipe_close)(struct trace_iterator *iter);
577 	ssize_t			(*read)(struct trace_iterator *iter,
578 					struct file *filp, char __user *ubuf,
579 					size_t cnt, loff_t *ppos);
580 	ssize_t			(*splice_read)(struct trace_iterator *iter,
581 					       struct file *filp,
582 					       loff_t *ppos,
583 					       struct pipe_inode_info *pipe,
584 					       size_t len,
585 					       unsigned int flags);
586 #ifdef CONFIG_FTRACE_STARTUP_TEST
587 	int			(*selftest)(struct tracer *trace,
588 					    struct trace_array *tr);
589 #endif
590 	void			(*print_header)(struct seq_file *m);
591 	enum print_line_t	(*print_line)(struct trace_iterator *iter);
592 	/* If you handled the flag setting, return 0 */
593 	int			(*set_flag)(struct trace_array *tr,
594 					    u32 old_flags, u32 bit, int set);
595 	/* Return 0 if OK with change, else return non-zero */
596 	int			(*flag_changed)(struct trace_array *tr,
597 						u32 mask, int set);
598 	struct tracer		*next;
599 	struct tracer_flags	*flags;
600 	int			enabled;
601 	bool			print_max;
602 	bool			allow_instances;
603 #ifdef CONFIG_TRACER_MAX_TRACE
604 	bool			use_max_tr;
605 #endif
606 	/* True if tracer cannot be enabled in kernel param */
607 	bool			noboot;
608 };
609 
610 static inline struct ring_buffer_iter *
611 trace_buffer_iter(struct trace_iterator *iter, int cpu)
612 {
613 	return iter->buffer_iter ? iter->buffer_iter[cpu] : NULL;
614 }
615 
616 int tracer_init(struct tracer *t, struct trace_array *tr);
617 int tracing_is_enabled(void);
618 void tracing_reset_online_cpus(struct array_buffer *buf);
619 void tracing_reset_all_online_cpus(void);
620 void tracing_reset_all_online_cpus_unlocked(void);
621 int tracing_open_generic(struct inode *inode, struct file *filp);
622 int tracing_open_generic_tr(struct inode *inode, struct file *filp);
623 int tracing_release_generic_tr(struct inode *inode, struct file *file);
624 int tracing_open_file_tr(struct inode *inode, struct file *filp);
625 int tracing_release_file_tr(struct inode *inode, struct file *filp);
626 int tracing_single_release_file_tr(struct inode *inode, struct file *filp);
627 bool tracing_is_disabled(void);
628 bool tracer_tracing_is_on(struct trace_array *tr);
629 void tracer_tracing_on(struct trace_array *tr);
630 void tracer_tracing_off(struct trace_array *tr);
631 struct dentry *trace_create_file(const char *name,
632 				 umode_t mode,
633 				 struct dentry *parent,
634 				 void *data,
635 				 const struct file_operations *fops);
636 
637 int tracing_init_dentry(void);
638 
639 struct ring_buffer_event;
640 
641 struct ring_buffer_event *
642 trace_buffer_lock_reserve(struct trace_buffer *buffer,
643 			  int type,
644 			  unsigned long len,
645 			  unsigned int trace_ctx);
646 
647 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
648 						struct trace_array_cpu *data);
649 
650 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
651 					  int *ent_cpu, u64 *ent_ts);
652 
653 void trace_buffer_unlock_commit_nostack(struct trace_buffer *buffer,
654 					struct ring_buffer_event *event);
655 
656 bool trace_is_tracepoint_string(const char *str);
657 const char *trace_event_format(struct trace_iterator *iter, const char *fmt);
658 void trace_check_vprintf(struct trace_iterator *iter, const char *fmt,
659 			 va_list ap) __printf(2, 0);
660 char *trace_iter_expand_format(struct trace_iterator *iter);
661 
662 int trace_empty(struct trace_iterator *iter);
663 
664 void *trace_find_next_entry_inc(struct trace_iterator *iter);
665 
666 void trace_init_global_iter(struct trace_iterator *iter);
667 
668 void tracing_iter_reset(struct trace_iterator *iter, int cpu);
669 
670 unsigned long trace_total_entries_cpu(struct trace_array *tr, int cpu);
671 unsigned long trace_total_entries(struct trace_array *tr);
672 
673 void trace_function(struct trace_array *tr,
674 		    unsigned long ip,
675 		    unsigned long parent_ip,
676 		    unsigned int trace_ctx);
677 void trace_graph_function(struct trace_array *tr,
678 		    unsigned long ip,
679 		    unsigned long parent_ip,
680 		    unsigned int trace_ctx);
681 void trace_latency_header(struct seq_file *m);
682 void trace_default_header(struct seq_file *m);
683 void print_trace_header(struct seq_file *m, struct trace_iterator *iter);
684 
685 void trace_graph_return(struct ftrace_graph_ret *trace, struct fgraph_ops *gops);
686 int trace_graph_entry(struct ftrace_graph_ent *trace, struct fgraph_ops *gops);
687 
688 void tracing_start_cmdline_record(void);
689 void tracing_stop_cmdline_record(void);
690 void tracing_start_tgid_record(void);
691 void tracing_stop_tgid_record(void);
692 
693 int register_tracer(struct tracer *type);
694 int is_tracing_stopped(void);
695 
696 loff_t tracing_lseek(struct file *file, loff_t offset, int whence);
697 
698 extern cpumask_var_t __read_mostly tracing_buffer_mask;
699 
700 #define for_each_tracing_cpu(cpu)	\
701 	for_each_cpu(cpu, tracing_buffer_mask)
702 
703 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
704 
705 extern unsigned long tracing_thresh;
706 
707 /* PID filtering */
708 
709 extern int pid_max;
710 
711 bool trace_find_filtered_pid(struct trace_pid_list *filtered_pids,
712 			     pid_t search_pid);
713 bool trace_ignore_this_task(struct trace_pid_list *filtered_pids,
714 			    struct trace_pid_list *filtered_no_pids,
715 			    struct task_struct *task);
716 void trace_filter_add_remove_task(struct trace_pid_list *pid_list,
717 				  struct task_struct *self,
718 				  struct task_struct *task);
719 void *trace_pid_next(struct trace_pid_list *pid_list, void *v, loff_t *pos);
720 void *trace_pid_start(struct trace_pid_list *pid_list, loff_t *pos);
721 int trace_pid_show(struct seq_file *m, void *v);
722 int trace_pid_write(struct trace_pid_list *filtered_pids,
723 		    struct trace_pid_list **new_pid_list,
724 		    const char __user *ubuf, size_t cnt);
725 
726 #ifdef CONFIG_TRACER_MAX_TRACE
727 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu,
728 		   void *cond_data);
729 void update_max_tr_single(struct trace_array *tr,
730 			  struct task_struct *tsk, int cpu);
731 
732 #ifdef CONFIG_FSNOTIFY
733 #define LATENCY_FS_NOTIFY
734 #endif
735 #endif /* CONFIG_TRACER_MAX_TRACE */
736 
737 #ifdef LATENCY_FS_NOTIFY
738 void latency_fsnotify(struct trace_array *tr);
739 #else
740 static inline void latency_fsnotify(struct trace_array *tr) { }
741 #endif
742 
743 #ifdef CONFIG_STACKTRACE
744 void __trace_stack(struct trace_array *tr, unsigned int trace_ctx, int skip);
745 #else
746 static inline void __trace_stack(struct trace_array *tr, unsigned int trace_ctx,
747 				 int skip)
748 {
749 }
750 #endif /* CONFIG_STACKTRACE */
751 
752 void trace_last_func_repeats(struct trace_array *tr,
753 			     struct trace_func_repeats *last_info,
754 			     unsigned int trace_ctx);
755 
756 extern u64 ftrace_now(int cpu);
757 
758 extern void trace_find_cmdline(int pid, char comm[]);
759 extern int trace_find_tgid(int pid);
760 extern void trace_event_follow_fork(struct trace_array *tr, bool enable);
761 
762 #ifdef CONFIG_DYNAMIC_FTRACE
763 extern unsigned long ftrace_update_tot_cnt;
764 extern unsigned long ftrace_number_of_pages;
765 extern unsigned long ftrace_number_of_groups;
766 void ftrace_init_trace_array(struct trace_array *tr);
767 #else
768 static inline void ftrace_init_trace_array(struct trace_array *tr) { }
769 #endif
770 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
771 extern int DYN_FTRACE_TEST_NAME(void);
772 #define DYN_FTRACE_TEST_NAME2 trace_selftest_dynamic_test_func2
773 extern int DYN_FTRACE_TEST_NAME2(void);
774 
775 extern void trace_set_ring_buffer_expanded(struct trace_array *tr);
776 extern bool tracing_selftest_disabled;
777 
778 #ifdef CONFIG_FTRACE_STARTUP_TEST
779 extern void __init disable_tracing_selftest(const char *reason);
780 
781 extern int trace_selftest_startup_function(struct tracer *trace,
782 					   struct trace_array *tr);
783 extern int trace_selftest_startup_function_graph(struct tracer *trace,
784 						 struct trace_array *tr);
785 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
786 					  struct trace_array *tr);
787 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
788 					     struct trace_array *tr);
789 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
790 						 struct trace_array *tr);
791 extern int trace_selftest_startup_wakeup(struct tracer *trace,
792 					 struct trace_array *tr);
793 extern int trace_selftest_startup_nop(struct tracer *trace,
794 					 struct trace_array *tr);
795 extern int trace_selftest_startup_branch(struct tracer *trace,
796 					 struct trace_array *tr);
797 /*
798  * Tracer data references selftest functions that only occur
799  * on boot up. These can be __init functions. Thus, when selftests
800  * are enabled, then the tracers need to reference __init functions.
801  */
802 #define __tracer_data		__refdata
803 #else
804 static inline void __init disable_tracing_selftest(const char *reason)
805 {
806 }
807 /* Tracers are seldom changed. Optimize when selftests are disabled. */
808 #define __tracer_data		__read_mostly
809 #endif /* CONFIG_FTRACE_STARTUP_TEST */
810 
811 extern void *head_page(struct trace_array_cpu *data);
812 extern unsigned long long ns2usecs(u64 nsec);
813 extern int
814 trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
815 extern int
816 trace_vprintk(unsigned long ip, const char *fmt, va_list args);
817 extern int
818 trace_array_vprintk(struct trace_array *tr,
819 		    unsigned long ip, const char *fmt, va_list args);
820 int trace_array_printk_buf(struct trace_buffer *buffer,
821 			   unsigned long ip, const char *fmt, ...);
822 void trace_printk_seq(struct trace_seq *s);
823 enum print_line_t print_trace_line(struct trace_iterator *iter);
824 
825 extern char trace_find_mark(unsigned long long duration);
826 
827 struct ftrace_hash;
828 
829 struct ftrace_mod_load {
830 	struct list_head	list;
831 	char			*func;
832 	char			*module;
833 	int			 enable;
834 };
835 
836 enum {
837 	FTRACE_HASH_FL_MOD	= (1 << 0),
838 };
839 
840 struct ftrace_hash {
841 	unsigned long		size_bits;
842 	struct hlist_head	*buckets;
843 	unsigned long		count;
844 	unsigned long		flags;
845 	struct rcu_head		rcu;
846 };
847 
848 struct ftrace_func_entry *
849 ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip);
850 
851 static __always_inline bool ftrace_hash_empty(struct ftrace_hash *hash)
852 {
853 	return !hash || !(hash->count || (hash->flags & FTRACE_HASH_FL_MOD));
854 }
855 
856 /* Standard output formatting function used for function return traces */
857 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
858 
859 /* Flag options */
860 #define TRACE_GRAPH_PRINT_OVERRUN       0x1
861 #define TRACE_GRAPH_PRINT_CPU           0x2
862 #define TRACE_GRAPH_PRINT_OVERHEAD      0x4
863 #define TRACE_GRAPH_PRINT_PROC          0x8
864 #define TRACE_GRAPH_PRINT_DURATION      0x10
865 #define TRACE_GRAPH_PRINT_ABS_TIME      0x20
866 #define TRACE_GRAPH_PRINT_REL_TIME      0x40
867 #define TRACE_GRAPH_PRINT_IRQS          0x80
868 #define TRACE_GRAPH_PRINT_TAIL          0x100
869 #define TRACE_GRAPH_SLEEP_TIME          0x200
870 #define TRACE_GRAPH_GRAPH_TIME          0x400
871 #define TRACE_GRAPH_PRINT_RETVAL        0x800
872 #define TRACE_GRAPH_PRINT_RETVAL_HEX    0x1000
873 #define TRACE_GRAPH_PRINT_FILL_SHIFT	28
874 #define TRACE_GRAPH_PRINT_FILL_MASK	(0x3 << TRACE_GRAPH_PRINT_FILL_SHIFT)
875 
876 extern void ftrace_graph_sleep_time_control(bool enable);
877 
878 #ifdef CONFIG_FUNCTION_PROFILER
879 extern void ftrace_graph_graph_time_control(bool enable);
880 #else
881 static inline void ftrace_graph_graph_time_control(bool enable) { }
882 #endif
883 
884 extern enum print_line_t
885 print_graph_function_flags(struct trace_iterator *iter, u32 flags);
886 extern void print_graph_headers_flags(struct seq_file *s, u32 flags);
887 extern void
888 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
889 extern void graph_trace_open(struct trace_iterator *iter);
890 extern void graph_trace_close(struct trace_iterator *iter);
891 extern int __trace_graph_entry(struct trace_array *tr,
892 			       struct ftrace_graph_ent *trace,
893 			       unsigned int trace_ctx);
894 extern void __trace_graph_return(struct trace_array *tr,
895 				 struct ftrace_graph_ret *trace,
896 				 unsigned int trace_ctx);
897 extern void init_array_fgraph_ops(struct trace_array *tr, struct ftrace_ops *ops);
898 extern int allocate_fgraph_ops(struct trace_array *tr, struct ftrace_ops *ops);
899 extern void free_fgraph_ops(struct trace_array *tr);
900 
901 enum {
902 	TRACE_GRAPH_FL		= 1,
903 
904 	/*
905 	 * In the very unlikely case that an interrupt came in
906 	 * at a start of graph tracing, and we want to trace
907 	 * the function in that interrupt, the depth can be greater
908 	 * than zero, because of the preempted start of a previous
909 	 * trace. In an even more unlikely case, depth could be 2
910 	 * if a softirq interrupted the start of graph tracing,
911 	 * followed by an interrupt preempting a start of graph
912 	 * tracing in the softirq, and depth can even be 3
913 	 * if an NMI came in at the start of an interrupt function
914 	 * that preempted a softirq start of a function that
915 	 * preempted normal context!!!! Luckily, it can't be
916 	 * greater than 3, so the next two bits are a mask
917 	 * of what the depth is when we set TRACE_GRAPH_FL
918 	 */
919 
920 	TRACE_GRAPH_DEPTH_START_BIT,
921 	TRACE_GRAPH_DEPTH_END_BIT,
922 
923 	/*
924 	 * To implement set_graph_notrace, if this bit is set, we ignore
925 	 * function graph tracing of called functions, until the return
926 	 * function is called to clear it.
927 	 */
928 	TRACE_GRAPH_NOTRACE_BIT,
929 };
930 
931 #define TRACE_GRAPH_NOTRACE		(1 << TRACE_GRAPH_NOTRACE_BIT)
932 
933 static inline unsigned long ftrace_graph_depth(unsigned long *task_var)
934 {
935 	return (*task_var >> TRACE_GRAPH_DEPTH_START_BIT) & 3;
936 }
937 
938 static inline void ftrace_graph_set_depth(unsigned long *task_var, int depth)
939 {
940 	*task_var &= ~(3 << TRACE_GRAPH_DEPTH_START_BIT);
941 	*task_var |= (depth & 3) << TRACE_GRAPH_DEPTH_START_BIT;
942 }
943 
944 #ifdef CONFIG_DYNAMIC_FTRACE
945 extern struct ftrace_hash __rcu *ftrace_graph_hash;
946 extern struct ftrace_hash __rcu *ftrace_graph_notrace_hash;
947 
948 static inline int
949 ftrace_graph_addr(unsigned long *task_var, struct ftrace_graph_ent *trace)
950 {
951 	unsigned long addr = trace->func;
952 	int ret = 0;
953 	struct ftrace_hash *hash;
954 
955 	preempt_disable_notrace();
956 
957 	/*
958 	 * Have to open code "rcu_dereference_sched()" because the
959 	 * function graph tracer can be called when RCU is not
960 	 * "watching".
961 	 * Protected with schedule_on_each_cpu(ftrace_sync)
962 	 */
963 	hash = rcu_dereference_protected(ftrace_graph_hash, !preemptible());
964 
965 	if (ftrace_hash_empty(hash)) {
966 		ret = 1;
967 		goto out;
968 	}
969 
970 	if (ftrace_lookup_ip(hash, addr)) {
971 		/*
972 		 * This needs to be cleared on the return functions
973 		 * when the depth is zero.
974 		 */
975 		*task_var |= TRACE_GRAPH_FL;
976 		ftrace_graph_set_depth(task_var, trace->depth);
977 
978 		/*
979 		 * If no irqs are to be traced, but a set_graph_function
980 		 * is set, and called by an interrupt handler, we still
981 		 * want to trace it.
982 		 */
983 		if (in_hardirq())
984 			trace_recursion_set(TRACE_IRQ_BIT);
985 		else
986 			trace_recursion_clear(TRACE_IRQ_BIT);
987 		ret = 1;
988 	}
989 
990 out:
991 	preempt_enable_notrace();
992 	return ret;
993 }
994 
995 static inline void
996 ftrace_graph_addr_finish(struct fgraph_ops *gops, struct ftrace_graph_ret *trace)
997 {
998 	unsigned long *task_var = fgraph_get_task_var(gops);
999 
1000 	if ((*task_var & TRACE_GRAPH_FL) &&
1001 	    trace->depth == ftrace_graph_depth(task_var))
1002 		*task_var &= ~TRACE_GRAPH_FL;
1003 }
1004 
1005 static inline int ftrace_graph_notrace_addr(unsigned long addr)
1006 {
1007 	int ret = 0;
1008 	struct ftrace_hash *notrace_hash;
1009 
1010 	preempt_disable_notrace();
1011 
1012 	/*
1013 	 * Have to open code "rcu_dereference_sched()" because the
1014 	 * function graph tracer can be called when RCU is not
1015 	 * "watching".
1016 	 * Protected with schedule_on_each_cpu(ftrace_sync)
1017 	 */
1018 	notrace_hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
1019 						 !preemptible());
1020 
1021 	if (ftrace_lookup_ip(notrace_hash, addr))
1022 		ret = 1;
1023 
1024 	preempt_enable_notrace();
1025 	return ret;
1026 }
1027 #else
1028 static inline int ftrace_graph_addr(unsigned long *task_var, struct ftrace_graph_ent *trace)
1029 {
1030 	return 1;
1031 }
1032 
1033 static inline int ftrace_graph_notrace_addr(unsigned long addr)
1034 {
1035 	return 0;
1036 }
1037 static inline void ftrace_graph_addr_finish(struct fgraph_ops *gops, struct ftrace_graph_ret *trace)
1038 { }
1039 #endif /* CONFIG_DYNAMIC_FTRACE */
1040 
1041 extern unsigned int fgraph_max_depth;
1042 
1043 static inline bool
1044 ftrace_graph_ignore_func(struct fgraph_ops *gops, struct ftrace_graph_ent *trace)
1045 {
1046 	unsigned long *task_var = fgraph_get_task_var(gops);
1047 
1048 	/* trace it when it is-nested-in or is a function enabled. */
1049 	return !((*task_var & TRACE_GRAPH_FL) ||
1050 		 ftrace_graph_addr(task_var, trace)) ||
1051 		(trace->depth < 0) ||
1052 		(fgraph_max_depth && trace->depth >= fgraph_max_depth);
1053 }
1054 
1055 void fgraph_init_ops(struct ftrace_ops *dst_ops,
1056 		     struct ftrace_ops *src_ops);
1057 
1058 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
1059 static inline enum print_line_t
1060 print_graph_function_flags(struct trace_iterator *iter, u32 flags)
1061 {
1062 	return TRACE_TYPE_UNHANDLED;
1063 }
1064 static inline void free_fgraph_ops(struct trace_array *tr) { }
1065 /* ftrace_ops may not be defined */
1066 #define init_array_fgraph_ops(tr, ops) do { } while (0)
1067 #define allocate_fgraph_ops(tr, ops) ({ 0; })
1068 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
1069 
1070 extern struct list_head ftrace_pids;
1071 
1072 #ifdef CONFIG_FUNCTION_TRACER
1073 
1074 #define FTRACE_PID_IGNORE	-1
1075 #define FTRACE_PID_TRACE	-2
1076 
1077 struct ftrace_func_command {
1078 	struct list_head	list;
1079 	char			*name;
1080 	int			(*func)(struct trace_array *tr,
1081 					struct ftrace_hash *hash,
1082 					char *func, char *cmd,
1083 					char *params, int enable);
1084 };
1085 extern bool ftrace_filter_param __initdata;
1086 static inline int ftrace_trace_task(struct trace_array *tr)
1087 {
1088 	return this_cpu_read(tr->array_buffer.data->ftrace_ignore_pid) !=
1089 		FTRACE_PID_IGNORE;
1090 }
1091 extern int ftrace_is_dead(void);
1092 int ftrace_create_function_files(struct trace_array *tr,
1093 				 struct dentry *parent);
1094 void ftrace_destroy_function_files(struct trace_array *tr);
1095 int ftrace_allocate_ftrace_ops(struct trace_array *tr);
1096 void ftrace_free_ftrace_ops(struct trace_array *tr);
1097 void ftrace_init_global_array_ops(struct trace_array *tr);
1098 void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func);
1099 void ftrace_reset_array_ops(struct trace_array *tr);
1100 void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer);
1101 void ftrace_init_tracefs_toplevel(struct trace_array *tr,
1102 				  struct dentry *d_tracer);
1103 void ftrace_clear_pids(struct trace_array *tr);
1104 int init_function_trace(void);
1105 void ftrace_pid_follow_fork(struct trace_array *tr, bool enable);
1106 #else
1107 static inline int ftrace_trace_task(struct trace_array *tr)
1108 {
1109 	return 1;
1110 }
1111 static inline int ftrace_is_dead(void) { return 0; }
1112 static inline int
1113 ftrace_create_function_files(struct trace_array *tr,
1114 			     struct dentry *parent)
1115 {
1116 	return 0;
1117 }
1118 static inline int ftrace_allocate_ftrace_ops(struct trace_array *tr)
1119 {
1120 	return 0;
1121 }
1122 static inline void ftrace_free_ftrace_ops(struct trace_array *tr) { }
1123 static inline void ftrace_destroy_function_files(struct trace_array *tr) { }
1124 static inline __init void
1125 ftrace_init_global_array_ops(struct trace_array *tr) { }
1126 static inline void ftrace_reset_array_ops(struct trace_array *tr) { }
1127 static inline void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d) { }
1128 static inline void ftrace_init_tracefs_toplevel(struct trace_array *tr, struct dentry *d) { }
1129 static inline void ftrace_clear_pids(struct trace_array *tr) { }
1130 static inline int init_function_trace(void) { return 0; }
1131 static inline void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) { }
1132 /* ftace_func_t type is not defined, use macro instead of static inline */
1133 #define ftrace_init_array_ops(tr, func) do { } while (0)
1134 #endif /* CONFIG_FUNCTION_TRACER */
1135 
1136 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
1137 
1138 struct ftrace_probe_ops {
1139 	void			(*func)(unsigned long ip,
1140 					unsigned long parent_ip,
1141 					struct trace_array *tr,
1142 					struct ftrace_probe_ops *ops,
1143 					void *data);
1144 	int			(*init)(struct ftrace_probe_ops *ops,
1145 					struct trace_array *tr,
1146 					unsigned long ip, void *init_data,
1147 					void **data);
1148 	void			(*free)(struct ftrace_probe_ops *ops,
1149 					struct trace_array *tr,
1150 					unsigned long ip, void *data);
1151 	int			(*print)(struct seq_file *m,
1152 					 unsigned long ip,
1153 					 struct ftrace_probe_ops *ops,
1154 					 void *data);
1155 };
1156 
1157 struct ftrace_func_mapper;
1158 typedef int (*ftrace_mapper_func)(void *data);
1159 
1160 struct ftrace_func_mapper *allocate_ftrace_func_mapper(void);
1161 void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
1162 					   unsigned long ip);
1163 int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
1164 			       unsigned long ip, void *data);
1165 void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
1166 				   unsigned long ip);
1167 void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
1168 			     ftrace_mapper_func free_func);
1169 
1170 extern int
1171 register_ftrace_function_probe(char *glob, struct trace_array *tr,
1172 			       struct ftrace_probe_ops *ops, void *data);
1173 extern int
1174 unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
1175 				      struct ftrace_probe_ops *ops);
1176 extern void clear_ftrace_function_probes(struct trace_array *tr);
1177 
1178 int register_ftrace_command(struct ftrace_func_command *cmd);
1179 int unregister_ftrace_command(struct ftrace_func_command *cmd);
1180 
1181 void ftrace_create_filter_files(struct ftrace_ops *ops,
1182 				struct dentry *parent);
1183 void ftrace_destroy_filter_files(struct ftrace_ops *ops);
1184 
1185 extern int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
1186 			     int len, int reset);
1187 extern int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
1188 			      int len, int reset);
1189 #else
1190 struct ftrace_func_command;
1191 
1192 static inline __init int register_ftrace_command(struct ftrace_func_command *cmd)
1193 {
1194 	return -EINVAL;
1195 }
1196 static inline __init int unregister_ftrace_command(char *cmd_name)
1197 {
1198 	return -EINVAL;
1199 }
1200 static inline void clear_ftrace_function_probes(struct trace_array *tr)
1201 {
1202 }
1203 
1204 /*
1205  * The ops parameter passed in is usually undefined.
1206  * This must be a macro.
1207  */
1208 #define ftrace_create_filter_files(ops, parent) do { } while (0)
1209 #define ftrace_destroy_filter_files(ops) do { } while (0)
1210 #endif /* CONFIG_FUNCTION_TRACER && CONFIG_DYNAMIC_FTRACE */
1211 
1212 bool ftrace_event_is_function(struct trace_event_call *call);
1213 
1214 /*
1215  * struct trace_parser - servers for reading the user input separated by spaces
1216  * @cont: set if the input is not complete - no final space char was found
1217  * @buffer: holds the parsed user input
1218  * @idx: user input length
1219  * @size: buffer size
1220  */
1221 struct trace_parser {
1222 	bool		cont;
1223 	char		*buffer;
1224 	unsigned	idx;
1225 	unsigned	size;
1226 };
1227 
1228 static inline bool trace_parser_loaded(struct trace_parser *parser)
1229 {
1230 	return (parser->idx != 0);
1231 }
1232 
1233 static inline bool trace_parser_cont(struct trace_parser *parser)
1234 {
1235 	return parser->cont;
1236 }
1237 
1238 static inline void trace_parser_clear(struct trace_parser *parser)
1239 {
1240 	parser->cont = false;
1241 	parser->idx = 0;
1242 }
1243 
1244 extern int trace_parser_get_init(struct trace_parser *parser, int size);
1245 extern void trace_parser_put(struct trace_parser *parser);
1246 extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
1247 	size_t cnt, loff_t *ppos);
1248 
1249 /*
1250  * Only create function graph options if function graph is configured.
1251  */
1252 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1253 # define FGRAPH_FLAGS						\
1254 		C(DISPLAY_GRAPH,	"display-graph"),
1255 #else
1256 # define FGRAPH_FLAGS
1257 #endif
1258 
1259 #ifdef CONFIG_BRANCH_TRACER
1260 # define BRANCH_FLAGS					\
1261 		C(BRANCH,		"branch"),
1262 #else
1263 # define BRANCH_FLAGS
1264 #endif
1265 
1266 #ifdef CONFIG_FUNCTION_TRACER
1267 # define FUNCTION_FLAGS						\
1268 		C(FUNCTION,		"function-trace"),	\
1269 		C(FUNC_FORK,		"function-fork"),
1270 # define FUNCTION_DEFAULT_FLAGS		TRACE_ITER_FUNCTION
1271 #else
1272 # define FUNCTION_FLAGS
1273 # define FUNCTION_DEFAULT_FLAGS		0UL
1274 # define TRACE_ITER_FUNC_FORK		0UL
1275 #endif
1276 
1277 #ifdef CONFIG_STACKTRACE
1278 # define STACK_FLAGS				\
1279 		C(STACKTRACE,		"stacktrace"),
1280 #else
1281 # define STACK_FLAGS
1282 #endif
1283 
1284 /*
1285  * trace_iterator_flags is an enumeration that defines bit
1286  * positions into trace_flags that controls the output.
1287  *
1288  * NOTE: These bits must match the trace_options array in
1289  *       trace.c (this macro guarantees it).
1290  */
1291 #define TRACE_FLAGS						\
1292 		C(PRINT_PARENT,		"print-parent"),	\
1293 		C(SYM_OFFSET,		"sym-offset"),		\
1294 		C(SYM_ADDR,		"sym-addr"),		\
1295 		C(VERBOSE,		"verbose"),		\
1296 		C(RAW,			"raw"),			\
1297 		C(HEX,			"hex"),			\
1298 		C(BIN,			"bin"),			\
1299 		C(BLOCK,		"block"),		\
1300 		C(FIELDS,		"fields"),		\
1301 		C(PRINTK,		"trace_printk"),	\
1302 		C(ANNOTATE,		"annotate"),		\
1303 		C(USERSTACKTRACE,	"userstacktrace"),	\
1304 		C(SYM_USEROBJ,		"sym-userobj"),		\
1305 		C(PRINTK_MSGONLY,	"printk-msg-only"),	\
1306 		C(CONTEXT_INFO,		"context-info"),   /* Print pid/cpu/time */ \
1307 		C(LATENCY_FMT,		"latency-format"),	\
1308 		C(RECORD_CMD,		"record-cmd"),		\
1309 		C(RECORD_TGID,		"record-tgid"),		\
1310 		C(OVERWRITE,		"overwrite"),		\
1311 		C(STOP_ON_FREE,		"disable_on_free"),	\
1312 		C(IRQ_INFO,		"irq-info"),		\
1313 		C(MARKERS,		"markers"),		\
1314 		C(EVENT_FORK,		"event-fork"),		\
1315 		C(PAUSE_ON_TRACE,	"pause-on-trace"),	\
1316 		C(HASH_PTR,		"hash-ptr"),	/* Print hashed pointer */ \
1317 		FUNCTION_FLAGS					\
1318 		FGRAPH_FLAGS					\
1319 		STACK_FLAGS					\
1320 		BRANCH_FLAGS
1321 
1322 /*
1323  * By defining C, we can make TRACE_FLAGS a list of bit names
1324  * that will define the bits for the flag masks.
1325  */
1326 #undef C
1327 #define C(a, b) TRACE_ITER_##a##_BIT
1328 
1329 enum trace_iterator_bits {
1330 	TRACE_FLAGS
1331 	/* Make sure we don't go more than we have bits for */
1332 	TRACE_ITER_LAST_BIT
1333 };
1334 
1335 /*
1336  * By redefining C, we can make TRACE_FLAGS a list of masks that
1337  * use the bits as defined above.
1338  */
1339 #undef C
1340 #define C(a, b) TRACE_ITER_##a = (1 << TRACE_ITER_##a##_BIT)
1341 
1342 enum trace_iterator_flags { TRACE_FLAGS };
1343 
1344 /*
1345  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
1346  * control the output of kernel symbols.
1347  */
1348 #define TRACE_ITER_SYM_MASK \
1349 	(TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
1350 
1351 extern struct tracer nop_trace;
1352 
1353 #ifdef CONFIG_BRANCH_TRACER
1354 extern int enable_branch_tracing(struct trace_array *tr);
1355 extern void disable_branch_tracing(void);
1356 static inline int trace_branch_enable(struct trace_array *tr)
1357 {
1358 	if (tr->trace_flags & TRACE_ITER_BRANCH)
1359 		return enable_branch_tracing(tr);
1360 	return 0;
1361 }
1362 static inline void trace_branch_disable(void)
1363 {
1364 	/* due to races, always disable */
1365 	disable_branch_tracing();
1366 }
1367 #else
1368 static inline int trace_branch_enable(struct trace_array *tr)
1369 {
1370 	return 0;
1371 }
1372 static inline void trace_branch_disable(void)
1373 {
1374 }
1375 #endif /* CONFIG_BRANCH_TRACER */
1376 
1377 /* set ring buffers to default size if not already done so */
1378 int tracing_update_buffers(struct trace_array *tr);
1379 
1380 union trace_synth_field {
1381 	u8				as_u8;
1382 	u16				as_u16;
1383 	u32				as_u32;
1384 	u64				as_u64;
1385 	struct trace_dynamic_info	as_dynamic;
1386 };
1387 
1388 struct ftrace_event_field {
1389 	struct list_head	link;
1390 	const char		*name;
1391 	const char		*type;
1392 	int			filter_type;
1393 	int			offset;
1394 	int			size;
1395 	int			is_signed;
1396 	int			len;
1397 };
1398 
1399 struct prog_entry;
1400 
1401 struct event_filter {
1402 	struct prog_entry __rcu	*prog;
1403 	char			*filter_string;
1404 };
1405 
1406 struct event_subsystem {
1407 	struct list_head	list;
1408 	const char		*name;
1409 	struct event_filter	*filter;
1410 	int			ref_count;
1411 };
1412 
1413 struct trace_subsystem_dir {
1414 	struct list_head		list;
1415 	struct event_subsystem		*subsystem;
1416 	struct trace_array		*tr;
1417 	struct eventfs_inode		*ei;
1418 	int				ref_count;
1419 	int				nr_events;
1420 };
1421 
1422 extern int call_filter_check_discard(struct trace_event_call *call, void *rec,
1423 				     struct trace_buffer *buffer,
1424 				     struct ring_buffer_event *event);
1425 
1426 void trace_buffer_unlock_commit_regs(struct trace_array *tr,
1427 				     struct trace_buffer *buffer,
1428 				     struct ring_buffer_event *event,
1429 				     unsigned int trcace_ctx,
1430 				     struct pt_regs *regs);
1431 
1432 static inline void trace_buffer_unlock_commit(struct trace_array *tr,
1433 					      struct trace_buffer *buffer,
1434 					      struct ring_buffer_event *event,
1435 					      unsigned int trace_ctx)
1436 {
1437 	trace_buffer_unlock_commit_regs(tr, buffer, event, trace_ctx, NULL);
1438 }
1439 
1440 DECLARE_PER_CPU(bool, trace_taskinfo_save);
1441 int trace_save_cmdline(struct task_struct *tsk);
1442 int trace_create_savedcmd(void);
1443 int trace_alloc_tgid_map(void);
1444 void trace_free_saved_cmdlines_buffer(void);
1445 
1446 extern const struct file_operations tracing_saved_cmdlines_fops;
1447 extern const struct file_operations tracing_saved_tgids_fops;
1448 extern const struct file_operations tracing_saved_cmdlines_size_fops;
1449 
1450 DECLARE_PER_CPU(struct ring_buffer_event *, trace_buffered_event);
1451 DECLARE_PER_CPU(int, trace_buffered_event_cnt);
1452 void trace_buffered_event_disable(void);
1453 void trace_buffered_event_enable(void);
1454 
1455 void early_enable_events(struct trace_array *tr, char *buf, bool disable_first);
1456 
1457 static inline void
1458 __trace_event_discard_commit(struct trace_buffer *buffer,
1459 			     struct ring_buffer_event *event)
1460 {
1461 	if (this_cpu_read(trace_buffered_event) == event) {
1462 		/* Simply release the temp buffer and enable preemption */
1463 		this_cpu_dec(trace_buffered_event_cnt);
1464 		preempt_enable_notrace();
1465 		return;
1466 	}
1467 	/* ring_buffer_discard_commit() enables preemption */
1468 	ring_buffer_discard_commit(buffer, event);
1469 }
1470 
1471 /*
1472  * Helper function for event_trigger_unlock_commit{_regs}().
1473  * If there are event triggers attached to this event that requires
1474  * filtering against its fields, then they will be called as the
1475  * entry already holds the field information of the current event.
1476  *
1477  * It also checks if the event should be discarded or not.
1478  * It is to be discarded if the event is soft disabled and the
1479  * event was only recorded to process triggers, or if the event
1480  * filter is active and this event did not match the filters.
1481  *
1482  * Returns true if the event is discarded, false otherwise.
1483  */
1484 static inline bool
1485 __event_trigger_test_discard(struct trace_event_file *file,
1486 			     struct trace_buffer *buffer,
1487 			     struct ring_buffer_event *event,
1488 			     void *entry,
1489 			     enum event_trigger_type *tt)
1490 {
1491 	unsigned long eflags = file->flags;
1492 
1493 	if (eflags & EVENT_FILE_FL_TRIGGER_COND)
1494 		*tt = event_triggers_call(file, buffer, entry, event);
1495 
1496 	if (likely(!(file->flags & (EVENT_FILE_FL_SOFT_DISABLED |
1497 				    EVENT_FILE_FL_FILTERED |
1498 				    EVENT_FILE_FL_PID_FILTER))))
1499 		return false;
1500 
1501 	if (file->flags & EVENT_FILE_FL_SOFT_DISABLED)
1502 		goto discard;
1503 
1504 	if (file->flags & EVENT_FILE_FL_FILTERED &&
1505 	    !filter_match_preds(file->filter, entry))
1506 		goto discard;
1507 
1508 	if ((file->flags & EVENT_FILE_FL_PID_FILTER) &&
1509 	    trace_event_ignore_this_pid(file))
1510 		goto discard;
1511 
1512 	return false;
1513  discard:
1514 	__trace_event_discard_commit(buffer, event);
1515 	return true;
1516 }
1517 
1518 /**
1519  * event_trigger_unlock_commit - handle triggers and finish event commit
1520  * @file: The file pointer associated with the event
1521  * @buffer: The ring buffer that the event is being written to
1522  * @event: The event meta data in the ring buffer
1523  * @entry: The event itself
1524  * @trace_ctx: The tracing context flags.
1525  *
1526  * This is a helper function to handle triggers that require data
1527  * from the event itself. It also tests the event against filters and
1528  * if the event is soft disabled and should be discarded.
1529  */
1530 static inline void
1531 event_trigger_unlock_commit(struct trace_event_file *file,
1532 			    struct trace_buffer *buffer,
1533 			    struct ring_buffer_event *event,
1534 			    void *entry, unsigned int trace_ctx)
1535 {
1536 	enum event_trigger_type tt = ETT_NONE;
1537 
1538 	if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1539 		trace_buffer_unlock_commit(file->tr, buffer, event, trace_ctx);
1540 
1541 	if (tt)
1542 		event_triggers_post_call(file, tt);
1543 }
1544 
1545 #define FILTER_PRED_INVALID	((unsigned short)-1)
1546 #define FILTER_PRED_IS_RIGHT	(1 << 15)
1547 #define FILTER_PRED_FOLD	(1 << 15)
1548 
1549 /*
1550  * The max preds is the size of unsigned short with
1551  * two flags at the MSBs. One bit is used for both the IS_RIGHT
1552  * and FOLD flags. The other is reserved.
1553  *
1554  * 2^14 preds is way more than enough.
1555  */
1556 #define MAX_FILTER_PRED		16384
1557 
1558 struct filter_pred;
1559 struct regex;
1560 
1561 typedef int (*regex_match_func)(char *str, struct regex *r, int len);
1562 
1563 enum regex_type {
1564 	MATCH_FULL = 0,
1565 	MATCH_FRONT_ONLY,
1566 	MATCH_MIDDLE_ONLY,
1567 	MATCH_END_ONLY,
1568 	MATCH_GLOB,
1569 	MATCH_INDEX,
1570 };
1571 
1572 struct regex {
1573 	char			pattern[MAX_FILTER_STR_VAL];
1574 	int			len;
1575 	int			field_len;
1576 	regex_match_func	match;
1577 };
1578 
1579 static inline bool is_string_field(struct ftrace_event_field *field)
1580 {
1581 	return field->filter_type == FILTER_DYN_STRING ||
1582 	       field->filter_type == FILTER_RDYN_STRING ||
1583 	       field->filter_type == FILTER_STATIC_STRING ||
1584 	       field->filter_type == FILTER_PTR_STRING ||
1585 	       field->filter_type == FILTER_COMM;
1586 }
1587 
1588 static inline bool is_function_field(struct ftrace_event_field *field)
1589 {
1590 	return field->filter_type == FILTER_TRACE_FN;
1591 }
1592 
1593 extern enum regex_type
1594 filter_parse_regex(char *buff, int len, char **search, int *not);
1595 extern void print_event_filter(struct trace_event_file *file,
1596 			       struct trace_seq *s);
1597 extern int apply_event_filter(struct trace_event_file *file,
1598 			      char *filter_string);
1599 extern int apply_subsystem_event_filter(struct trace_subsystem_dir *dir,
1600 					char *filter_string);
1601 extern void print_subsystem_event_filter(struct event_subsystem *system,
1602 					 struct trace_seq *s);
1603 extern int filter_assign_type(const char *type);
1604 extern int create_event_filter(struct trace_array *tr,
1605 			       struct trace_event_call *call,
1606 			       char *filter_str, bool set_str,
1607 			       struct event_filter **filterp);
1608 extern void free_event_filter(struct event_filter *filter);
1609 
1610 struct ftrace_event_field *
1611 trace_find_event_field(struct trace_event_call *call, char *name);
1612 
1613 extern void trace_event_enable_cmd_record(bool enable);
1614 extern void trace_event_enable_tgid_record(bool enable);
1615 
1616 extern int event_trace_init(void);
1617 extern int init_events(void);
1618 extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
1619 extern int event_trace_del_tracer(struct trace_array *tr);
1620 extern void __trace_early_add_events(struct trace_array *tr);
1621 
1622 extern struct trace_event_file *__find_event_file(struct trace_array *tr,
1623 						  const char *system,
1624 						  const char *event);
1625 extern struct trace_event_file *find_event_file(struct trace_array *tr,
1626 						const char *system,
1627 						const char *event);
1628 
1629 static inline void *event_file_data(struct file *filp)
1630 {
1631 	return READ_ONCE(file_inode(filp)->i_private);
1632 }
1633 
1634 extern struct mutex event_mutex;
1635 extern struct list_head ftrace_events;
1636 
1637 /*
1638  * When the trace_event_file is the filp->i_private pointer,
1639  * it must be taken under the event_mutex lock, and then checked
1640  * if the EVENT_FILE_FL_FREED flag is set. If it is, then the
1641  * data pointed to by the trace_event_file can not be trusted.
1642  *
1643  * Use the event_file_file() to access the trace_event_file from
1644  * the filp the first time under the event_mutex and check for
1645  * NULL. If it is needed to be retrieved again and the event_mutex
1646  * is still held, then the event_file_data() can be used and it
1647  * is guaranteed to be valid.
1648  */
1649 static inline struct trace_event_file *event_file_file(struct file *filp)
1650 {
1651 	struct trace_event_file *file;
1652 
1653 	lockdep_assert_held(&event_mutex);
1654 	file = READ_ONCE(file_inode(filp)->i_private);
1655 	if (!file || file->flags & EVENT_FILE_FL_FREED)
1656 		return NULL;
1657 	return file;
1658 }
1659 
1660 extern const struct file_operations event_trigger_fops;
1661 extern const struct file_operations event_hist_fops;
1662 extern const struct file_operations event_hist_debug_fops;
1663 extern const struct file_operations event_inject_fops;
1664 
1665 #ifdef CONFIG_HIST_TRIGGERS
1666 extern int register_trigger_hist_cmd(void);
1667 extern int register_trigger_hist_enable_disable_cmds(void);
1668 #else
1669 static inline int register_trigger_hist_cmd(void) { return 0; }
1670 static inline int register_trigger_hist_enable_disable_cmds(void) { return 0; }
1671 #endif
1672 
1673 extern int register_trigger_cmds(void);
1674 extern void clear_event_triggers(struct trace_array *tr);
1675 
1676 enum {
1677 	EVENT_TRIGGER_FL_PROBE		= BIT(0),
1678 };
1679 
1680 struct event_trigger_data {
1681 	unsigned long			count;
1682 	int				ref;
1683 	int				flags;
1684 	struct event_trigger_ops	*ops;
1685 	struct event_command		*cmd_ops;
1686 	struct event_filter __rcu	*filter;
1687 	char				*filter_str;
1688 	void				*private_data;
1689 	bool				paused;
1690 	bool				paused_tmp;
1691 	struct list_head		list;
1692 	char				*name;
1693 	struct list_head		named_list;
1694 	struct event_trigger_data	*named_data;
1695 };
1696 
1697 /* Avoid typos */
1698 #define ENABLE_EVENT_STR	"enable_event"
1699 #define DISABLE_EVENT_STR	"disable_event"
1700 #define ENABLE_HIST_STR		"enable_hist"
1701 #define DISABLE_HIST_STR	"disable_hist"
1702 
1703 struct enable_trigger_data {
1704 	struct trace_event_file		*file;
1705 	bool				enable;
1706 	bool				hist;
1707 };
1708 
1709 extern int event_enable_trigger_print(struct seq_file *m,
1710 				      struct event_trigger_data *data);
1711 extern void event_enable_trigger_free(struct event_trigger_data *data);
1712 extern int event_enable_trigger_parse(struct event_command *cmd_ops,
1713 				      struct trace_event_file *file,
1714 				      char *glob, char *cmd,
1715 				      char *param_and_filter);
1716 extern int event_enable_register_trigger(char *glob,
1717 					 struct event_trigger_data *data,
1718 					 struct trace_event_file *file);
1719 extern void event_enable_unregister_trigger(char *glob,
1720 					    struct event_trigger_data *test,
1721 					    struct trace_event_file *file);
1722 extern void trigger_data_free(struct event_trigger_data *data);
1723 extern int event_trigger_init(struct event_trigger_data *data);
1724 extern int trace_event_trigger_enable_disable(struct trace_event_file *file,
1725 					      int trigger_enable);
1726 extern void update_cond_flag(struct trace_event_file *file);
1727 extern int set_trigger_filter(char *filter_str,
1728 			      struct event_trigger_data *trigger_data,
1729 			      struct trace_event_file *file);
1730 extern struct event_trigger_data *find_named_trigger(const char *name);
1731 extern bool is_named_trigger(struct event_trigger_data *test);
1732 extern int save_named_trigger(const char *name,
1733 			      struct event_trigger_data *data);
1734 extern void del_named_trigger(struct event_trigger_data *data);
1735 extern void pause_named_trigger(struct event_trigger_data *data);
1736 extern void unpause_named_trigger(struct event_trigger_data *data);
1737 extern void set_named_trigger_data(struct event_trigger_data *data,
1738 				   struct event_trigger_data *named_data);
1739 extern struct event_trigger_data *
1740 get_named_trigger_data(struct event_trigger_data *data);
1741 extern int register_event_command(struct event_command *cmd);
1742 extern int unregister_event_command(struct event_command *cmd);
1743 extern int register_trigger_hist_enable_disable_cmds(void);
1744 extern bool event_trigger_check_remove(const char *glob);
1745 extern bool event_trigger_empty_param(const char *param);
1746 extern int event_trigger_separate_filter(char *param_and_filter, char **param,
1747 					 char **filter, bool param_required);
1748 extern struct event_trigger_data *
1749 event_trigger_alloc(struct event_command *cmd_ops,
1750 		    char *cmd,
1751 		    char *param,
1752 		    void *private_data);
1753 extern int event_trigger_parse_num(char *trigger,
1754 				   struct event_trigger_data *trigger_data);
1755 extern int event_trigger_set_filter(struct event_command *cmd_ops,
1756 				    struct trace_event_file *file,
1757 				    char *param,
1758 				    struct event_trigger_data *trigger_data);
1759 extern void event_trigger_reset_filter(struct event_command *cmd_ops,
1760 				       struct event_trigger_data *trigger_data);
1761 extern int event_trigger_register(struct event_command *cmd_ops,
1762 				  struct trace_event_file *file,
1763 				  char *glob,
1764 				  struct event_trigger_data *trigger_data);
1765 extern void event_trigger_unregister(struct event_command *cmd_ops,
1766 				     struct trace_event_file *file,
1767 				     char *glob,
1768 				     struct event_trigger_data *trigger_data);
1769 
1770 extern void event_file_get(struct trace_event_file *file);
1771 extern void event_file_put(struct trace_event_file *file);
1772 
1773 /**
1774  * struct event_trigger_ops - callbacks for trace event triggers
1775  *
1776  * The methods in this structure provide per-event trigger hooks for
1777  * various trigger operations.
1778  *
1779  * The @init and @free methods are used during trigger setup and
1780  * teardown, typically called from an event_command's @parse()
1781  * function implementation.
1782  *
1783  * The @print method is used to print the trigger spec.
1784  *
1785  * The @trigger method is the function that actually implements the
1786  * trigger and is called in the context of the triggering event
1787  * whenever that event occurs.
1788  *
1789  * All the methods below, except for @init() and @free(), must be
1790  * implemented.
1791  *
1792  * @trigger: The trigger 'probe' function called when the triggering
1793  *	event occurs.  The data passed into this callback is the data
1794  *	that was supplied to the event_command @reg() function that
1795  *	registered the trigger (see struct event_command) along with
1796  *	the trace record, rec.
1797  *
1798  * @init: An optional initialization function called for the trigger
1799  *	when the trigger is registered (via the event_command reg()
1800  *	function).  This can be used to perform per-trigger
1801  *	initialization such as incrementing a per-trigger reference
1802  *	count, for instance.  This is usually implemented by the
1803  *	generic utility function @event_trigger_init() (see
1804  *	trace_event_triggers.c).
1805  *
1806  * @free: An optional de-initialization function called for the
1807  *	trigger when the trigger is unregistered (via the
1808  *	event_command @reg() function).  This can be used to perform
1809  *	per-trigger de-initialization such as decrementing a
1810  *	per-trigger reference count and freeing corresponding trigger
1811  *	data, for instance.  This is usually implemented by the
1812  *	generic utility function @event_trigger_free() (see
1813  *	trace_event_triggers.c).
1814  *
1815  * @print: The callback function invoked to have the trigger print
1816  *	itself.  This is usually implemented by a wrapper function
1817  *	that calls the generic utility function @event_trigger_print()
1818  *	(see trace_event_triggers.c).
1819  */
1820 struct event_trigger_ops {
1821 	void			(*trigger)(struct event_trigger_data *data,
1822 					   struct trace_buffer *buffer,
1823 					   void *rec,
1824 					   struct ring_buffer_event *rbe);
1825 	int			(*init)(struct event_trigger_data *data);
1826 	void			(*free)(struct event_trigger_data *data);
1827 	int			(*print)(struct seq_file *m,
1828 					 struct event_trigger_data *data);
1829 };
1830 
1831 /**
1832  * struct event_command - callbacks and data members for event commands
1833  *
1834  * Event commands are invoked by users by writing the command name
1835  * into the 'trigger' file associated with a trace event.  The
1836  * parameters associated with a specific invocation of an event
1837  * command are used to create an event trigger instance, which is
1838  * added to the list of trigger instances associated with that trace
1839  * event.  When the event is hit, the set of triggers associated with
1840  * that event is invoked.
1841  *
1842  * The data members in this structure provide per-event command data
1843  * for various event commands.
1844  *
1845  * All the data members below, except for @post_trigger, must be set
1846  * for each event command.
1847  *
1848  * @name: The unique name that identifies the event command.  This is
1849  *	the name used when setting triggers via trigger files.
1850  *
1851  * @trigger_type: A unique id that identifies the event command
1852  *	'type'.  This value has two purposes, the first to ensure that
1853  *	only one trigger of the same type can be set at a given time
1854  *	for a particular event e.g. it doesn't make sense to have both
1855  *	a traceon and traceoff trigger attached to a single event at
1856  *	the same time, so traceon and traceoff have the same type
1857  *	though they have different names.  The @trigger_type value is
1858  *	also used as a bit value for deferring the actual trigger
1859  *	action until after the current event is finished.  Some
1860  *	commands need to do this if they themselves log to the trace
1861  *	buffer (see the @post_trigger() member below).  @trigger_type
1862  *	values are defined by adding new values to the trigger_type
1863  *	enum in include/linux/trace_events.h.
1864  *
1865  * @flags: See the enum event_command_flags below.
1866  *
1867  * All the methods below, except for @set_filter() and @unreg_all(),
1868  * must be implemented.
1869  *
1870  * @parse: The callback function responsible for parsing and
1871  *	registering the trigger written to the 'trigger' file by the
1872  *	user.  It allocates the trigger instance and registers it with
1873  *	the appropriate trace event.  It makes use of the other
1874  *	event_command callback functions to orchestrate this, and is
1875  *	usually implemented by the generic utility function
1876  *	@event_trigger_callback() (see trace_event_triggers.c).
1877  *
1878  * @reg: Adds the trigger to the list of triggers associated with the
1879  *	event, and enables the event trigger itself, after
1880  *	initializing it (via the event_trigger_ops @init() function).
1881  *	This is also where commands can use the @trigger_type value to
1882  *	make the decision as to whether or not multiple instances of
1883  *	the trigger should be allowed.  This is usually implemented by
1884  *	the generic utility function @register_trigger() (see
1885  *	trace_event_triggers.c).
1886  *
1887  * @unreg: Removes the trigger from the list of triggers associated
1888  *	with the event, and disables the event trigger itself, after
1889  *	initializing it (via the event_trigger_ops @free() function).
1890  *	This is usually implemented by the generic utility function
1891  *	@unregister_trigger() (see trace_event_triggers.c).
1892  *
1893  * @unreg_all: An optional function called to remove all the triggers
1894  *	from the list of triggers associated with the event.  Called
1895  *	when a trigger file is opened in truncate mode.
1896  *
1897  * @set_filter: An optional function called to parse and set a filter
1898  *	for the trigger.  If no @set_filter() method is set for the
1899  *	event command, filters set by the user for the command will be
1900  *	ignored.  This is usually implemented by the generic utility
1901  *	function @set_trigger_filter() (see trace_event_triggers.c).
1902  *
1903  * @get_trigger_ops: The callback function invoked to retrieve the
1904  *	event_trigger_ops implementation associated with the command.
1905  *	This callback function allows a single event_command to
1906  *	support multiple trigger implementations via different sets of
1907  *	event_trigger_ops, depending on the value of the @param
1908  *	string.
1909  */
1910 struct event_command {
1911 	struct list_head	list;
1912 	char			*name;
1913 	enum event_trigger_type	trigger_type;
1914 	int			flags;
1915 	int			(*parse)(struct event_command *cmd_ops,
1916 					 struct trace_event_file *file,
1917 					 char *glob, char *cmd,
1918 					 char *param_and_filter);
1919 	int			(*reg)(char *glob,
1920 				       struct event_trigger_data *data,
1921 				       struct trace_event_file *file);
1922 	void			(*unreg)(char *glob,
1923 					 struct event_trigger_data *data,
1924 					 struct trace_event_file *file);
1925 	void			(*unreg_all)(struct trace_event_file *file);
1926 	int			(*set_filter)(char *filter_str,
1927 					      struct event_trigger_data *data,
1928 					      struct trace_event_file *file);
1929 	struct event_trigger_ops *(*get_trigger_ops)(char *cmd, char *param);
1930 };
1931 
1932 /**
1933  * enum event_command_flags - flags for struct event_command
1934  *
1935  * @POST_TRIGGER: A flag that says whether or not this command needs
1936  *	to have its action delayed until after the current event has
1937  *	been closed.  Some triggers need to avoid being invoked while
1938  *	an event is currently in the process of being logged, since
1939  *	the trigger may itself log data into the trace buffer.  Thus
1940  *	we make sure the current event is committed before invoking
1941  *	those triggers.  To do that, the trigger invocation is split
1942  *	in two - the first part checks the filter using the current
1943  *	trace record; if a command has the @post_trigger flag set, it
1944  *	sets a bit for itself in the return value, otherwise it
1945  *	directly invokes the trigger.  Once all commands have been
1946  *	either invoked or set their return flag, the current record is
1947  *	either committed or discarded.  At that point, if any commands
1948  *	have deferred their triggers, those commands are finally
1949  *	invoked following the close of the current event.  In other
1950  *	words, if the event_trigger_ops @func() probe implementation
1951  *	itself logs to the trace buffer, this flag should be set,
1952  *	otherwise it can be left unspecified.
1953  *
1954  * @NEEDS_REC: A flag that says whether or not this command needs
1955  *	access to the trace record in order to perform its function,
1956  *	regardless of whether or not it has a filter associated with
1957  *	it (filters make a trigger require access to the trace record
1958  *	but are not always present).
1959  */
1960 enum event_command_flags {
1961 	EVENT_CMD_FL_POST_TRIGGER	= 1,
1962 	EVENT_CMD_FL_NEEDS_REC		= 2,
1963 };
1964 
1965 static inline bool event_command_post_trigger(struct event_command *cmd_ops)
1966 {
1967 	return cmd_ops->flags & EVENT_CMD_FL_POST_TRIGGER;
1968 }
1969 
1970 static inline bool event_command_needs_rec(struct event_command *cmd_ops)
1971 {
1972 	return cmd_ops->flags & EVENT_CMD_FL_NEEDS_REC;
1973 }
1974 
1975 extern int trace_event_enable_disable(struct trace_event_file *file,
1976 				      int enable, int soft_disable);
1977 extern int tracing_alloc_snapshot(void);
1978 extern void tracing_snapshot_cond(struct trace_array *tr, void *cond_data);
1979 extern int tracing_snapshot_cond_enable(struct trace_array *tr, void *cond_data, cond_update_fn_t update);
1980 
1981 extern int tracing_snapshot_cond_disable(struct trace_array *tr);
1982 extern void *tracing_cond_snapshot_data(struct trace_array *tr);
1983 
1984 extern const char *__start___trace_bprintk_fmt[];
1985 extern const char *__stop___trace_bprintk_fmt[];
1986 
1987 extern const char *__start___tracepoint_str[];
1988 extern const char *__stop___tracepoint_str[];
1989 
1990 void trace_printk_control(bool enabled);
1991 void trace_printk_start_comm(void);
1992 int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set);
1993 int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled);
1994 
1995 /* Used from boot time tracer */
1996 extern int trace_set_options(struct trace_array *tr, char *option);
1997 extern int tracing_set_tracer(struct trace_array *tr, const char *buf);
1998 extern ssize_t tracing_resize_ring_buffer(struct trace_array *tr,
1999 					  unsigned long size, int cpu_id);
2000 extern int tracing_set_cpumask(struct trace_array *tr,
2001 				cpumask_var_t tracing_cpumask_new);
2002 
2003 
2004 #define MAX_EVENT_NAME_LEN	64
2005 
2006 extern ssize_t trace_parse_run_command(struct file *file,
2007 		const char __user *buffer, size_t count, loff_t *ppos,
2008 		int (*createfn)(const char *));
2009 
2010 extern unsigned int err_pos(char *cmd, const char *str);
2011 extern void tracing_log_err(struct trace_array *tr,
2012 			    const char *loc, const char *cmd,
2013 			    const char **errs, u8 type, u16 pos);
2014 
2015 /*
2016  * Normal trace_printk() and friends allocates special buffers
2017  * to do the manipulation, as well as saves the print formats
2018  * into sections to display. But the trace infrastructure wants
2019  * to use these without the added overhead at the price of being
2020  * a bit slower (used mainly for warnings, where we don't care
2021  * about performance). The internal_trace_puts() is for such
2022  * a purpose.
2023  */
2024 #define internal_trace_puts(str) __trace_puts(_THIS_IP_, str, strlen(str))
2025 
2026 #undef FTRACE_ENTRY
2027 #define FTRACE_ENTRY(call, struct_name, id, tstruct, print)	\
2028 	extern struct trace_event_call					\
2029 	__aligned(4) event_##call;
2030 #undef FTRACE_ENTRY_DUP
2031 #define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print)	\
2032 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
2033 #undef FTRACE_ENTRY_PACKED
2034 #define FTRACE_ENTRY_PACKED(call, struct_name, id, tstruct, print) \
2035 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
2036 
2037 #include "trace_entries.h"
2038 
2039 #if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_FUNCTION_TRACER)
2040 int perf_ftrace_event_register(struct trace_event_call *call,
2041 			       enum trace_reg type, void *data);
2042 #else
2043 #define perf_ftrace_event_register NULL
2044 #endif
2045 
2046 #ifdef CONFIG_FTRACE_SYSCALLS
2047 void init_ftrace_syscalls(void);
2048 const char *get_syscall_name(int syscall);
2049 #else
2050 static inline void init_ftrace_syscalls(void) { }
2051 static inline const char *get_syscall_name(int syscall)
2052 {
2053 	return NULL;
2054 }
2055 #endif
2056 
2057 #ifdef CONFIG_EVENT_TRACING
2058 void trace_event_init(void);
2059 void trace_event_eval_update(struct trace_eval_map **map, int len);
2060 /* Used from boot time tracer */
2061 extern int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set);
2062 extern int trigger_process_regex(struct trace_event_file *file, char *buff);
2063 #else
2064 static inline void __init trace_event_init(void) { }
2065 static inline void trace_event_eval_update(struct trace_eval_map **map, int len) { }
2066 #endif
2067 
2068 #ifdef CONFIG_TRACER_SNAPSHOT
2069 void tracing_snapshot_instance(struct trace_array *tr);
2070 int tracing_alloc_snapshot_instance(struct trace_array *tr);
2071 int tracing_arm_snapshot(struct trace_array *tr);
2072 void tracing_disarm_snapshot(struct trace_array *tr);
2073 #else
2074 static inline void tracing_snapshot_instance(struct trace_array *tr) { }
2075 static inline int tracing_alloc_snapshot_instance(struct trace_array *tr)
2076 {
2077 	return 0;
2078 }
2079 static inline int tracing_arm_snapshot(struct trace_array *tr) { return 0; }
2080 static inline void tracing_disarm_snapshot(struct trace_array *tr) { }
2081 #endif
2082 
2083 #ifdef CONFIG_PREEMPT_TRACER
2084 void tracer_preempt_on(unsigned long a0, unsigned long a1);
2085 void tracer_preempt_off(unsigned long a0, unsigned long a1);
2086 #else
2087 static inline void tracer_preempt_on(unsigned long a0, unsigned long a1) { }
2088 static inline void tracer_preempt_off(unsigned long a0, unsigned long a1) { }
2089 #endif
2090 #ifdef CONFIG_IRQSOFF_TRACER
2091 void tracer_hardirqs_on(unsigned long a0, unsigned long a1);
2092 void tracer_hardirqs_off(unsigned long a0, unsigned long a1);
2093 #else
2094 static inline void tracer_hardirqs_on(unsigned long a0, unsigned long a1) { }
2095 static inline void tracer_hardirqs_off(unsigned long a0, unsigned long a1) { }
2096 #endif
2097 
2098 /*
2099  * Reset the state of the trace_iterator so that it can read consumed data.
2100  * Normally, the trace_iterator is used for reading the data when it is not
2101  * consumed, and must retain state.
2102  */
2103 static __always_inline void trace_iterator_reset(struct trace_iterator *iter)
2104 {
2105 	memset_startat(iter, 0, seq);
2106 	iter->pos = -1;
2107 }
2108 
2109 /* Check the name is good for event/group/fields */
2110 static inline bool __is_good_name(const char *name, bool hash_ok)
2111 {
2112 	if (!isalpha(*name) && *name != '_' && (!hash_ok || *name != '-'))
2113 		return false;
2114 	while (*++name != '\0') {
2115 		if (!isalpha(*name) && !isdigit(*name) && *name != '_' &&
2116 		    (!hash_ok || *name != '-'))
2117 			return false;
2118 	}
2119 	return true;
2120 }
2121 
2122 /* Check the name is good for event/group/fields */
2123 static inline bool is_good_name(const char *name)
2124 {
2125 	return __is_good_name(name, false);
2126 }
2127 
2128 /* Check the name is good for system */
2129 static inline bool is_good_system_name(const char *name)
2130 {
2131 	return __is_good_name(name, true);
2132 }
2133 
2134 /* Convert certain expected symbols into '_' when generating event names */
2135 static inline void sanitize_event_name(char *name)
2136 {
2137 	while (*name++ != '\0')
2138 		if (*name == ':' || *name == '.')
2139 			*name = '_';
2140 }
2141 
2142 /*
2143  * This is a generic way to read and write a u64 value from a file in tracefs.
2144  *
2145  * The value is stored on the variable pointed by *val. The value needs
2146  * to be at least *min and at most *max. The write is protected by an
2147  * existing *lock.
2148  */
2149 struct trace_min_max_param {
2150 	struct mutex	*lock;
2151 	u64		*val;
2152 	u64		*min;
2153 	u64		*max;
2154 };
2155 
2156 #define U64_STR_SIZE		24	/* 20 digits max */
2157 
2158 extern const struct file_operations trace_min_max_fops;
2159 
2160 #ifdef CONFIG_RV
2161 extern int rv_init_interface(void);
2162 #else
2163 static inline int rv_init_interface(void)
2164 {
2165 	return 0;
2166 }
2167 #endif
2168 
2169 #endif /* _LINUX_KERNEL_TRACE_H */
2170