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 #include <linux/ftrace_regs.h>
25 
26 #include "pid_list.h"
27 
28 #ifdef CONFIG_FTRACE_SYSCALLS
29 #include <asm/unistd.h>		/* For NR_syscalls	     */
30 #include <asm/syscall.h>	/* some archs define it here */
31 #endif
32 
33 #define TRACE_MODE_WRITE	0640
34 #define TRACE_MODE_READ		0440
35 
36 enum trace_type {
37 	__TRACE_FIRST_TYPE = 0,
38 
39 	TRACE_FN,
40 	TRACE_CTX,
41 	TRACE_WAKE,
42 	TRACE_STACK,
43 	TRACE_PRINT,
44 	TRACE_BPRINT,
45 	TRACE_MMIO_RW,
46 	TRACE_MMIO_MAP,
47 	TRACE_BRANCH,
48 	TRACE_GRAPH_RET,
49 	TRACE_GRAPH_ENT,
50 	TRACE_GRAPH_RETADDR_ENT,
51 	TRACE_USER_STACK,
52 	TRACE_BLK,
53 	TRACE_BPUTS,
54 	TRACE_HWLAT,
55 	TRACE_OSNOISE,
56 	TRACE_TIMERLAT,
57 	TRACE_RAW_DATA,
58 	TRACE_FUNC_REPEATS,
59 
60 	__TRACE_LAST_TYPE,
61 };
62 
63 
64 #undef __field
65 #define __field(type, item)		type	item;
66 
67 #undef __field_fn
68 #define __field_fn(type, item)		type	item;
69 
70 #undef __field_struct
71 #define __field_struct(type, item)	__field(type, item)
72 
73 #undef __field_desc
74 #define __field_desc(type, container, item)
75 
76 #undef __field_packed
77 #define __field_packed(type, container, item)
78 
79 #undef __array
80 #define __array(type, item, size)	type	item[size];
81 
82 /*
83  * For backward compatibility, older user space expects to see the
84  * kernel_stack event with a fixed size caller field. But today the fix
85  * size is ignored by the kernel, and the real structure is dynamic.
86  * Expose to user space: "unsigned long caller[8];" but the real structure
87  * will be "unsigned long caller[] __counted_by(size)"
88  */
89 #undef __stack_array
90 #define __stack_array(type, item, size, field)		type item[] __counted_by(field);
91 
92 #undef __array_desc
93 #define __array_desc(type, container, item, size)
94 
95 #undef __dynamic_array
96 #define __dynamic_array(type, item)	type	item[];
97 
98 #undef __rel_dynamic_array
99 #define __rel_dynamic_array(type, item)	type	item[];
100 
101 #undef F_STRUCT
102 #define F_STRUCT(args...)		args
103 
104 #undef FTRACE_ENTRY
105 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print)		\
106 	struct struct_name {						\
107 		struct trace_entry	ent;				\
108 		tstruct							\
109 	}
110 
111 #undef FTRACE_ENTRY_DUP
112 #define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk)
113 
114 #undef FTRACE_ENTRY_REG
115 #define FTRACE_ENTRY_REG(name, struct_name, id, tstruct, print,	regfn)	\
116 	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print))
117 
118 #undef FTRACE_ENTRY_PACKED
119 #define FTRACE_ENTRY_PACKED(name, struct_name, id, tstruct, print)	\
120 	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print)) __packed
121 
122 #include "trace_entries.h"
123 
124 /* Use this for memory failure errors */
125 #define MEM_FAIL(condition, fmt, ...)					\
126 	DO_ONCE_LITE_IF(condition, pr_err, "ERROR: " fmt, ##__VA_ARGS__)
127 
128 #define FAULT_STRING "(fault)"
129 
130 #define HIST_STACKTRACE_DEPTH	16
131 #define HIST_STACKTRACE_SIZE	(HIST_STACKTRACE_DEPTH * sizeof(unsigned long))
132 #define HIST_STACKTRACE_SKIP	5
133 
134 /*
135  * syscalls are special, and need special handling, this is why
136  * they are not included in trace_entries.h
137  */
138 struct syscall_trace_enter {
139 	struct trace_entry	ent;
140 	int			nr;
141 	unsigned long		args[];
142 };
143 
144 struct syscall_trace_exit {
145 	struct trace_entry	ent;
146 	int			nr;
147 	long			ret;
148 };
149 
150 struct kprobe_trace_entry_head {
151 	struct trace_entry	ent;
152 	unsigned long		ip;
153 };
154 
155 struct eprobe_trace_entry_head {
156 	struct trace_entry	ent;
157 };
158 
159 struct kretprobe_trace_entry_head {
160 	struct trace_entry	ent;
161 	unsigned long		func;
162 	unsigned long		ret_ip;
163 };
164 
165 struct fentry_trace_entry_head {
166 	struct trace_entry	ent;
167 	unsigned long		ip;
168 };
169 
170 struct fexit_trace_entry_head {
171 	struct trace_entry	ent;
172 	unsigned long		func;
173 	unsigned long		ret_ip;
174 };
175 
176 #define TRACE_BUF_SIZE		1024
177 
178 struct trace_array;
179 
180 /*
181  * The CPU trace array - it consists of thousands of trace entries
182  * plus some other descriptor data: (for example which task started
183  * the trace, etc.)
184  */
185 struct trace_array_cpu {
186 	local_t			disabled;
187 
188 	unsigned long		entries;
189 	unsigned long		saved_latency;
190 	unsigned long		critical_start;
191 	unsigned long		critical_end;
192 	unsigned long		critical_sequence;
193 	unsigned long		nice;
194 	unsigned long		policy;
195 	unsigned long		rt_priority;
196 	unsigned long		skipped_entries;
197 	u64			preempt_timestamp;
198 	pid_t			pid;
199 	kuid_t			uid;
200 	char			comm[TASK_COMM_LEN];
201 
202 #ifdef CONFIG_FUNCTION_TRACER
203 	int			ftrace_ignore_pid;
204 #endif
205 	bool			ignore_pid;
206 };
207 
208 struct tracer;
209 struct trace_option_dentry;
210 
211 struct array_buffer {
212 	struct trace_array		*tr;
213 	struct trace_buffer		*buffer;
214 	struct trace_array_cpu __percpu	*data;
215 	u64				time_start;
216 	int				cpu;
217 };
218 
219 #define TRACE_FLAGS_MAX_SIZE		32
220 
221 struct trace_options {
222 	struct tracer			*tracer;
223 	struct trace_option_dentry	*topts;
224 };
225 
226 struct trace_pid_list *trace_pid_list_alloc(void);
227 void trace_pid_list_free(struct trace_pid_list *pid_list);
228 bool trace_pid_list_is_set(struct trace_pid_list *pid_list, unsigned int pid);
229 int trace_pid_list_set(struct trace_pid_list *pid_list, unsigned int pid);
230 int trace_pid_list_clear(struct trace_pid_list *pid_list, unsigned int pid);
231 int trace_pid_list_first(struct trace_pid_list *pid_list, unsigned int *pid);
232 int trace_pid_list_next(struct trace_pid_list *pid_list, unsigned int pid,
233 			unsigned int *next);
234 
235 enum {
236 	TRACE_PIDS		= BIT(0),
237 	TRACE_NO_PIDS		= BIT(1),
238 };
239 
240 static inline bool pid_type_enabled(int type, struct trace_pid_list *pid_list,
241 				    struct trace_pid_list *no_pid_list)
242 {
243 	/* Return true if the pid list in type has pids */
244 	return ((type & TRACE_PIDS) && pid_list) ||
245 		((type & TRACE_NO_PIDS) && no_pid_list);
246 }
247 
248 static inline bool still_need_pid_events(int type, struct trace_pid_list *pid_list,
249 					 struct trace_pid_list *no_pid_list)
250 {
251 	/*
252 	 * Turning off what is in @type, return true if the "other"
253 	 * pid list, still has pids in it.
254 	 */
255 	return (!(type & TRACE_PIDS) && pid_list) ||
256 		(!(type & TRACE_NO_PIDS) && no_pid_list);
257 }
258 
259 typedef bool (*cond_update_fn_t)(struct trace_array *tr, void *cond_data);
260 
261 /**
262  * struct cond_snapshot - conditional snapshot data and callback
263  *
264  * The cond_snapshot structure encapsulates a callback function and
265  * data associated with the snapshot for a given tracing instance.
266  *
267  * When a snapshot is taken conditionally, by invoking
268  * tracing_snapshot_cond(tr, cond_data), the cond_data passed in is
269  * passed in turn to the cond_snapshot.update() function.  That data
270  * can be compared by the update() implementation with the cond_data
271  * contained within the struct cond_snapshot instance associated with
272  * the trace_array.  Because the tr->max_lock is held throughout the
273  * update() call, the update() function can directly retrieve the
274  * cond_snapshot and cond_data associated with the per-instance
275  * snapshot associated with the trace_array.
276  *
277  * The cond_snapshot.update() implementation can save data to be
278  * associated with the snapshot if it decides to, and returns 'true'
279  * in that case, or it returns 'false' if the conditional snapshot
280  * shouldn't be taken.
281  *
282  * The cond_snapshot instance is created and associated with the
283  * user-defined cond_data by tracing_cond_snapshot_enable().
284  * Likewise, the cond_snapshot instance is destroyed and is no longer
285  * associated with the trace instance by
286  * tracing_cond_snapshot_disable().
287  *
288  * The method below is required.
289  *
290  * @update: When a conditional snapshot is invoked, the update()
291  *	callback function is invoked with the tr->max_lock held.  The
292  *	update() implementation signals whether or not to actually
293  *	take the snapshot, by returning 'true' if so, 'false' if no
294  *	snapshot should be taken.  Because the max_lock is held for
295  *	the duration of update(), the implementation is safe to
296  *	directly retrieved and save any implementation data it needs
297  *	to in association with the snapshot.
298  */
299 struct cond_snapshot {
300 	void				*cond_data;
301 	cond_update_fn_t		update;
302 };
303 
304 /*
305  * struct trace_func_repeats - used to keep track of the consecutive
306  * (on the same CPU) calls of a single function.
307  */
308 struct trace_func_repeats {
309 	unsigned long	ip;
310 	unsigned long	parent_ip;
311 	unsigned long	count;
312 	u64		ts_last_call;
313 };
314 
315 struct trace_module_delta {
316 	struct rcu_head	rcu;
317 	long		delta[];
318 };
319 
320 /*
321  * The trace array - an array of per-CPU trace arrays. This is the
322  * highest level data structure that individual tracers deal with.
323  * They have on/off state as well:
324  */
325 struct trace_array {
326 	struct list_head	list;
327 	char			*name;
328 	struct array_buffer	array_buffer;
329 #ifdef CONFIG_TRACER_MAX_TRACE
330 	/*
331 	 * The max_buffer is used to snapshot the trace when a maximum
332 	 * latency is reached, or when the user initiates a snapshot.
333 	 * Some tracers will use this to store a maximum trace while
334 	 * it continues examining live traces.
335 	 *
336 	 * The buffers for the max_buffer are set up the same as the array_buffer
337 	 * When a snapshot is taken, the buffer of the max_buffer is swapped
338 	 * with the buffer of the array_buffer and the buffers are reset for
339 	 * the array_buffer so the tracing can continue.
340 	 */
341 	struct array_buffer	max_buffer;
342 	bool			allocated_snapshot;
343 	spinlock_t		snapshot_trigger_lock;
344 	unsigned int		snapshot;
345 	unsigned long		max_latency;
346 #ifdef CONFIG_FSNOTIFY
347 	struct dentry		*d_max_latency;
348 	struct work_struct	fsnotify_work;
349 	struct irq_work		fsnotify_irqwork;
350 #endif
351 #endif
352 	/* The below is for memory mapped ring buffer */
353 	unsigned int		mapped;
354 	unsigned long		range_addr_start;
355 	unsigned long		range_addr_size;
356 	char			*range_name;
357 	long			text_delta;
358 	struct trace_module_delta *module_delta;
359 	void			*scratch; /* pointer in persistent memory */
360 	int			scratch_size;
361 
362 	int			buffer_disabled;
363 
364 	struct trace_pid_list	__rcu *filtered_pids;
365 	struct trace_pid_list	__rcu *filtered_no_pids;
366 	/*
367 	 * max_lock is used to protect the swapping of buffers
368 	 * when taking a max snapshot. The buffers themselves are
369 	 * protected by per_cpu spinlocks. But the action of the swap
370 	 * needs its own lock.
371 	 *
372 	 * This is defined as a arch_spinlock_t in order to help
373 	 * with performance when lockdep debugging is enabled.
374 	 *
375 	 * It is also used in other places outside the update_max_tr
376 	 * so it needs to be defined outside of the
377 	 * CONFIG_TRACER_MAX_TRACE.
378 	 */
379 	arch_spinlock_t		max_lock;
380 #ifdef CONFIG_FTRACE_SYSCALLS
381 	int			sys_refcount_enter;
382 	int			sys_refcount_exit;
383 	struct trace_event_file __rcu *enter_syscall_files[NR_syscalls];
384 	struct trace_event_file __rcu *exit_syscall_files[NR_syscalls];
385 #endif
386 	int			stop_count;
387 	int			clock_id;
388 	int			nr_topts;
389 	bool			clear_trace;
390 	int			buffer_percent;
391 	unsigned int		n_err_log_entries;
392 	struct tracer		*current_trace;
393 	unsigned int		trace_flags;
394 	unsigned char		trace_flags_index[TRACE_FLAGS_MAX_SIZE];
395 	unsigned int		flags;
396 	raw_spinlock_t		start_lock;
397 	const char		*system_names;
398 	struct list_head	err_log;
399 	struct dentry		*dir;
400 	struct dentry		*options;
401 	struct dentry		*percpu_dir;
402 	struct eventfs_inode	*event_dir;
403 	struct trace_options	*topts;
404 	struct list_head	systems;
405 	struct list_head	events;
406 	struct list_head	marker_list;
407 	struct trace_event_file *trace_marker_file;
408 	cpumask_var_t		tracing_cpumask; /* only trace on set CPUs */
409 	/* one per_cpu trace_pipe can be opened by only one user */
410 	cpumask_var_t		pipe_cpumask;
411 	int			ref;
412 	int			trace_ref;
413 #ifdef CONFIG_MODULES
414 	struct list_head	mod_events;
415 #endif
416 #ifdef CONFIG_FUNCTION_TRACER
417 	struct ftrace_ops	*ops;
418 	struct trace_pid_list	__rcu *function_pids;
419 	struct trace_pid_list	__rcu *function_no_pids;
420 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
421 	struct fgraph_ops	*gops;
422 #endif
423 #ifdef CONFIG_DYNAMIC_FTRACE
424 	/* All of these are protected by the ftrace_lock */
425 	struct list_head	func_probes;
426 	struct list_head	mod_trace;
427 	struct list_head	mod_notrace;
428 #endif
429 	/* function tracing enabled */
430 	int			function_enabled;
431 #endif
432 	int			no_filter_buffering_ref;
433 	struct list_head	hist_vars;
434 #ifdef CONFIG_TRACER_SNAPSHOT
435 	struct cond_snapshot	*cond_snapshot;
436 #endif
437 	struct trace_func_repeats	__percpu *last_func_repeats;
438 	/*
439 	 * On boot up, the ring buffer is set to the minimum size, so that
440 	 * we do not waste memory on systems that are not using tracing.
441 	 */
442 	bool ring_buffer_expanded;
443 };
444 
445 enum {
446 	TRACE_ARRAY_FL_GLOBAL		= BIT(0),
447 	TRACE_ARRAY_FL_BOOT		= BIT(1),
448 	TRACE_ARRAY_FL_LAST_BOOT	= BIT(2),
449 	TRACE_ARRAY_FL_MOD_INIT		= BIT(3),
450 	TRACE_ARRAY_FL_MEMMAP		= BIT(4),
451 };
452 
453 #ifdef CONFIG_MODULES
454 bool module_exists(const char *module);
455 #else
456 static inline bool module_exists(const char *module)
457 {
458 	return false;
459 }
460 #endif
461 
462 extern struct list_head ftrace_trace_arrays;
463 
464 extern struct mutex trace_types_lock;
465 
466 extern int trace_array_get(struct trace_array *tr);
467 extern int tracing_check_open_get_tr(struct trace_array *tr);
468 extern struct trace_array *trace_array_find(const char *instance);
469 extern struct trace_array *trace_array_find_get(const char *instance);
470 
471 extern u64 tracing_event_time_stamp(struct trace_buffer *buffer, struct ring_buffer_event *rbe);
472 extern int tracing_set_filter_buffering(struct trace_array *tr, bool set);
473 extern int tracing_set_clock(struct trace_array *tr, const char *clockstr);
474 
475 extern bool trace_clock_in_ns(struct trace_array *tr);
476 
477 extern unsigned long trace_adjust_address(struct trace_array *tr, unsigned long addr);
478 
479 /*
480  * The global tracer (top) should be the first trace array added,
481  * but we check the flag anyway.
482  */
483 static inline struct trace_array *top_trace_array(void)
484 {
485 	struct trace_array *tr;
486 
487 	if (list_empty(&ftrace_trace_arrays))
488 		return NULL;
489 
490 	tr = list_entry(ftrace_trace_arrays.prev,
491 			typeof(*tr), list);
492 	WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
493 	return tr;
494 }
495 
496 #define FTRACE_CMP_TYPE(var, type) \
497 	__builtin_types_compatible_p(typeof(var), type *)
498 
499 #undef IF_ASSIGN
500 #define IF_ASSIGN(var, entry, etype, id)			\
501 	if (FTRACE_CMP_TYPE(var, etype)) {			\
502 		var = (typeof(var))(entry);			\
503 		WARN_ON(id != 0 && (entry)->type != id);	\
504 		break;						\
505 	}
506 
507 /* Will cause compile errors if type is not found. */
508 extern void __ftrace_bad_type(void);
509 
510 /*
511  * The trace_assign_type is a verifier that the entry type is
512  * the same as the type being assigned. To add new types simply
513  * add a line with the following format:
514  *
515  * IF_ASSIGN(var, ent, type, id);
516  *
517  *  Where "type" is the trace type that includes the trace_entry
518  *  as the "ent" item. And "id" is the trace identifier that is
519  *  used in the trace_type enum.
520  *
521  *  If the type can have more than one id, then use zero.
522  */
523 #define trace_assign_type(var, ent)					\
524 	do {								\
525 		IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);	\
526 		IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);	\
527 		IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);	\
528 		IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
529 		IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);	\
530 		IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT);	\
531 		IF_ASSIGN(var, ent, struct bputs_entry, TRACE_BPUTS);	\
532 		IF_ASSIGN(var, ent, struct hwlat_entry, TRACE_HWLAT);	\
533 		IF_ASSIGN(var, ent, struct osnoise_entry, TRACE_OSNOISE);\
534 		IF_ASSIGN(var, ent, struct timerlat_entry, TRACE_TIMERLAT);\
535 		IF_ASSIGN(var, ent, struct raw_data_entry, TRACE_RAW_DATA);\
536 		IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,		\
537 			  TRACE_MMIO_RW);				\
538 		IF_ASSIGN(var, ent, struct trace_mmiotrace_map,		\
539 			  TRACE_MMIO_MAP);				\
540 		IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
541 		IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,	\
542 			  TRACE_GRAPH_ENT);		\
543 		IF_ASSIGN(var, ent, struct fgraph_retaddr_ent_entry,\
544 			  TRACE_GRAPH_RETADDR_ENT);		\
545 		IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,	\
546 			  TRACE_GRAPH_RET);		\
547 		IF_ASSIGN(var, ent, struct func_repeats_entry,		\
548 			  TRACE_FUNC_REPEATS);				\
549 		__ftrace_bad_type();					\
550 	} while (0)
551 
552 /*
553  * An option specific to a tracer. This is a boolean value.
554  * The bit is the bit index that sets its value on the
555  * flags value in struct tracer_flags.
556  */
557 struct tracer_opt {
558 	const char	*name; /* Will appear on the trace_options file */
559 	u32		bit; /* Mask assigned in val field in tracer_flags */
560 };
561 
562 /*
563  * The set of specific options for a tracer. Your tracer
564  * have to set the initial value of the flags val.
565  */
566 struct tracer_flags {
567 	u32			val;
568 	struct tracer_opt	*opts;
569 	struct tracer		*trace;
570 };
571 
572 /* Makes more easy to define a tracer opt */
573 #define TRACER_OPT(s, b)	.name = #s, .bit = b
574 
575 
576 struct trace_option_dentry {
577 	struct tracer_opt		*opt;
578 	struct tracer_flags		*flags;
579 	struct trace_array		*tr;
580 	struct dentry			*entry;
581 };
582 
583 /**
584  * struct tracer - a specific tracer and its callbacks to interact with tracefs
585  * @name: the name chosen to select it on the available_tracers file
586  * @init: called when one switches to this tracer (echo name > current_tracer)
587  * @reset: called when one switches to another tracer
588  * @start: called when tracing is unpaused (echo 1 > tracing_on)
589  * @stop: called when tracing is paused (echo 0 > tracing_on)
590  * @update_thresh: called when tracing_thresh is updated
591  * @open: called when the trace file is opened
592  * @pipe_open: called when the trace_pipe file is opened
593  * @close: called when the trace file is released
594  * @pipe_close: called when the trace_pipe file is released
595  * @read: override the default read callback on trace_pipe
596  * @splice_read: override the default splice_read callback on trace_pipe
597  * @selftest: selftest to run on boot (see trace_selftest.c)
598  * @print_headers: override the first lines that describe your columns
599  * @print_line: callback that prints a trace
600  * @set_flag: signals one of your private flags changed (trace_options file)
601  * @flags: your private flags
602  */
603 struct tracer {
604 	const char		*name;
605 	int			(*init)(struct trace_array *tr);
606 	void			(*reset)(struct trace_array *tr);
607 	void			(*start)(struct trace_array *tr);
608 	void			(*stop)(struct trace_array *tr);
609 	int			(*update_thresh)(struct trace_array *tr);
610 	void			(*open)(struct trace_iterator *iter);
611 	void			(*pipe_open)(struct trace_iterator *iter);
612 	void			(*close)(struct trace_iterator *iter);
613 	void			(*pipe_close)(struct trace_iterator *iter);
614 	ssize_t			(*read)(struct trace_iterator *iter,
615 					struct file *filp, char __user *ubuf,
616 					size_t cnt, loff_t *ppos);
617 	ssize_t			(*splice_read)(struct trace_iterator *iter,
618 					       struct file *filp,
619 					       loff_t *ppos,
620 					       struct pipe_inode_info *pipe,
621 					       size_t len,
622 					       unsigned int flags);
623 #ifdef CONFIG_FTRACE_STARTUP_TEST
624 	int			(*selftest)(struct tracer *trace,
625 					    struct trace_array *tr);
626 #endif
627 	void			(*print_header)(struct seq_file *m);
628 	enum print_line_t	(*print_line)(struct trace_iterator *iter);
629 	/* If you handled the flag setting, return 0 */
630 	int			(*set_flag)(struct trace_array *tr,
631 					    u32 old_flags, u32 bit, int set);
632 	/* Return 0 if OK with change, else return non-zero */
633 	int			(*flag_changed)(struct trace_array *tr,
634 						u32 mask, int set);
635 	struct tracer		*next;
636 	struct tracer_flags	*flags;
637 	int			enabled;
638 	bool			print_max;
639 	bool			allow_instances;
640 #ifdef CONFIG_TRACER_MAX_TRACE
641 	bool			use_max_tr;
642 #endif
643 	/* True if tracer cannot be enabled in kernel param */
644 	bool			noboot;
645 };
646 
647 static inline struct ring_buffer_iter *
648 trace_buffer_iter(struct trace_iterator *iter, int cpu)
649 {
650 	return iter->buffer_iter ? iter->buffer_iter[cpu] : NULL;
651 }
652 
653 int tracer_init(struct tracer *t, struct trace_array *tr);
654 int tracing_is_enabled(void);
655 void tracing_reset_online_cpus(struct array_buffer *buf);
656 void tracing_reset_all_online_cpus(void);
657 void tracing_reset_all_online_cpus_unlocked(void);
658 int tracing_open_generic(struct inode *inode, struct file *filp);
659 int tracing_open_generic_tr(struct inode *inode, struct file *filp);
660 int tracing_release_generic_tr(struct inode *inode, struct file *file);
661 int tracing_open_file_tr(struct inode *inode, struct file *filp);
662 int tracing_release_file_tr(struct inode *inode, struct file *filp);
663 int tracing_single_release_file_tr(struct inode *inode, struct file *filp);
664 bool tracing_is_disabled(void);
665 bool tracer_tracing_is_on(struct trace_array *tr);
666 void tracer_tracing_on(struct trace_array *tr);
667 void tracer_tracing_off(struct trace_array *tr);
668 void tracer_tracing_disable(struct trace_array *tr);
669 void tracer_tracing_enable(struct trace_array *tr);
670 struct dentry *trace_create_file(const char *name,
671 				 umode_t mode,
672 				 struct dentry *parent,
673 				 void *data,
674 				 const struct file_operations *fops);
675 
676 
677 /**
678  * tracer_tracing_is_on_cpu - show real state of ring buffer enabled on for a cpu
679  * @tr : the trace array to know if ring buffer is enabled
680  * @cpu: The cpu buffer to check if enabled
681  *
682  * Shows real state of the per CPU buffer if it is enabled or not.
683  */
684 static inline bool tracer_tracing_is_on_cpu(struct trace_array *tr, int cpu)
685 {
686 	if (tr->array_buffer.buffer)
687 		return ring_buffer_record_is_on_cpu(tr->array_buffer.buffer, cpu);
688 	return false;
689 }
690 
691 int tracing_init_dentry(void);
692 
693 struct ring_buffer_event;
694 
695 struct ring_buffer_event *
696 trace_buffer_lock_reserve(struct trace_buffer *buffer,
697 			  int type,
698 			  unsigned long len,
699 			  unsigned int trace_ctx);
700 
701 int ring_buffer_meta_seq_init(struct file *file, struct trace_buffer *buffer, int cpu);
702 
703 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
704 						struct trace_array_cpu *data);
705 
706 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
707 					  int *ent_cpu, u64 *ent_ts);
708 
709 void trace_buffer_unlock_commit_nostack(struct trace_buffer *buffer,
710 					struct ring_buffer_event *event);
711 
712 bool trace_is_tracepoint_string(const char *str);
713 const char *trace_event_format(struct trace_iterator *iter, const char *fmt);
714 char *trace_iter_expand_format(struct trace_iterator *iter);
715 bool ignore_event(struct trace_iterator *iter);
716 
717 int trace_empty(struct trace_iterator *iter);
718 
719 void *trace_find_next_entry_inc(struct trace_iterator *iter);
720 
721 void trace_init_global_iter(struct trace_iterator *iter);
722 
723 void tracing_iter_reset(struct trace_iterator *iter, int cpu);
724 
725 unsigned long trace_total_entries_cpu(struct trace_array *tr, int cpu);
726 unsigned long trace_total_entries(struct trace_array *tr);
727 
728 void trace_function(struct trace_array *tr,
729 		    unsigned long ip,
730 		    unsigned long parent_ip,
731 		    unsigned int trace_ctx,
732 		    struct ftrace_regs *regs);
733 void trace_graph_function(struct trace_array *tr,
734 		    unsigned long ip,
735 		    unsigned long parent_ip,
736 		    unsigned int trace_ctx);
737 void trace_latency_header(struct seq_file *m);
738 void trace_default_header(struct seq_file *m);
739 void print_trace_header(struct seq_file *m, struct trace_iterator *iter);
740 
741 void trace_graph_return(struct ftrace_graph_ret *trace, struct fgraph_ops *gops,
742 			struct ftrace_regs *fregs);
743 int trace_graph_entry(struct ftrace_graph_ent *trace, struct fgraph_ops *gops,
744 		      struct ftrace_regs *fregs);
745 
746 void tracing_start_cmdline_record(void);
747 void tracing_stop_cmdline_record(void);
748 void tracing_start_tgid_record(void);
749 void tracing_stop_tgid_record(void);
750 
751 int register_tracer(struct tracer *type);
752 int is_tracing_stopped(void);
753 
754 loff_t tracing_lseek(struct file *file, loff_t offset, int whence);
755 
756 extern cpumask_var_t __read_mostly tracing_buffer_mask;
757 
758 #define for_each_tracing_cpu(cpu)	\
759 	for_each_cpu(cpu, tracing_buffer_mask)
760 
761 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
762 
763 extern unsigned long tracing_thresh;
764 
765 /* PID filtering */
766 
767 bool trace_find_filtered_pid(struct trace_pid_list *filtered_pids,
768 			     pid_t search_pid);
769 bool trace_ignore_this_task(struct trace_pid_list *filtered_pids,
770 			    struct trace_pid_list *filtered_no_pids,
771 			    struct task_struct *task);
772 void trace_filter_add_remove_task(struct trace_pid_list *pid_list,
773 				  struct task_struct *self,
774 				  struct task_struct *task);
775 void *trace_pid_next(struct trace_pid_list *pid_list, void *v, loff_t *pos);
776 void *trace_pid_start(struct trace_pid_list *pid_list, loff_t *pos);
777 int trace_pid_show(struct seq_file *m, void *v);
778 int trace_pid_write(struct trace_pid_list *filtered_pids,
779 		    struct trace_pid_list **new_pid_list,
780 		    const char __user *ubuf, size_t cnt);
781 
782 #ifdef CONFIG_TRACER_MAX_TRACE
783 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu,
784 		   void *cond_data);
785 void update_max_tr_single(struct trace_array *tr,
786 			  struct task_struct *tsk, int cpu);
787 
788 #ifdef CONFIG_FSNOTIFY
789 #define LATENCY_FS_NOTIFY
790 #endif
791 #endif /* CONFIG_TRACER_MAX_TRACE */
792 
793 #ifdef LATENCY_FS_NOTIFY
794 void latency_fsnotify(struct trace_array *tr);
795 #else
796 static inline void latency_fsnotify(struct trace_array *tr) { }
797 #endif
798 
799 #ifdef CONFIG_STACKTRACE
800 void __trace_stack(struct trace_array *tr, unsigned int trace_ctx, int skip);
801 #else
802 static inline void __trace_stack(struct trace_array *tr, unsigned int trace_ctx,
803 				 int skip)
804 {
805 }
806 #endif /* CONFIG_STACKTRACE */
807 
808 void trace_last_func_repeats(struct trace_array *tr,
809 			     struct trace_func_repeats *last_info,
810 			     unsigned int trace_ctx);
811 
812 extern u64 ftrace_now(int cpu);
813 
814 extern void trace_find_cmdline(int pid, char comm[]);
815 extern int trace_find_tgid(int pid);
816 extern void trace_event_follow_fork(struct trace_array *tr, bool enable);
817 
818 extern int trace_events_enabled(struct trace_array *tr, const char *system);
819 
820 #ifdef CONFIG_DYNAMIC_FTRACE
821 extern unsigned long ftrace_update_tot_cnt;
822 extern unsigned long ftrace_number_of_pages;
823 extern unsigned long ftrace_number_of_groups;
824 extern u64 ftrace_update_time;
825 extern u64 ftrace_total_mod_time;
826 void ftrace_init_trace_array(struct trace_array *tr);
827 #else
828 static inline void ftrace_init_trace_array(struct trace_array *tr) { }
829 #endif
830 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
831 extern int DYN_FTRACE_TEST_NAME(void);
832 #define DYN_FTRACE_TEST_NAME2 trace_selftest_dynamic_test_func2
833 extern int DYN_FTRACE_TEST_NAME2(void);
834 
835 extern void trace_set_ring_buffer_expanded(struct trace_array *tr);
836 extern bool tracing_selftest_disabled;
837 
838 #ifdef CONFIG_FTRACE_STARTUP_TEST
839 extern void __init disable_tracing_selftest(const char *reason);
840 
841 extern int trace_selftest_startup_function(struct tracer *trace,
842 					   struct trace_array *tr);
843 extern int trace_selftest_startup_function_graph(struct tracer *trace,
844 						 struct trace_array *tr);
845 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
846 					  struct trace_array *tr);
847 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
848 					     struct trace_array *tr);
849 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
850 						 struct trace_array *tr);
851 extern int trace_selftest_startup_wakeup(struct tracer *trace,
852 					 struct trace_array *tr);
853 extern int trace_selftest_startup_nop(struct tracer *trace,
854 					 struct trace_array *tr);
855 extern int trace_selftest_startup_branch(struct tracer *trace,
856 					 struct trace_array *tr);
857 /*
858  * Tracer data references selftest functions that only occur
859  * on boot up. These can be __init functions. Thus, when selftests
860  * are enabled, then the tracers need to reference __init functions.
861  */
862 #define __tracer_data		__refdata
863 #else
864 static inline void __init disable_tracing_selftest(const char *reason)
865 {
866 }
867 /* Tracers are seldom changed. Optimize when selftests are disabled. */
868 #define __tracer_data		__read_mostly
869 #endif /* CONFIG_FTRACE_STARTUP_TEST */
870 
871 extern void *head_page(struct trace_array_cpu *data);
872 extern unsigned long long ns2usecs(u64 nsec);
873 
874 __printf(2, 0)
875 int trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
876 __printf(2, 0)
877 int trace_vprintk(unsigned long ip, const char *fmt, va_list args);
878 __printf(3, 0)
879 int trace_array_vprintk(struct trace_array *tr,
880 			unsigned long ip, const char *fmt, va_list args);
881 __printf(3, 4)
882 int trace_array_printk_buf(struct trace_buffer *buffer,
883 			   unsigned long ip, const char *fmt, ...);
884 void trace_printk_seq(struct trace_seq *s);
885 enum print_line_t print_trace_line(struct trace_iterator *iter);
886 
887 extern char trace_find_mark(unsigned long long duration);
888 
889 struct ftrace_hash;
890 
891 struct ftrace_mod_load {
892 	struct list_head	list;
893 	char			*func;
894 	char			*module;
895 	int			 enable;
896 };
897 
898 enum {
899 	FTRACE_HASH_FL_MOD	= (1 << 0),
900 };
901 
902 struct ftrace_hash {
903 	unsigned long		size_bits;
904 	struct hlist_head	*buckets;
905 	unsigned long		count;
906 	unsigned long		flags;
907 	struct rcu_head		rcu;
908 };
909 
910 struct ftrace_func_entry *
911 ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip);
912 
913 static __always_inline bool ftrace_hash_empty(struct ftrace_hash *hash)
914 {
915 	return !hash || !(hash->count || (hash->flags & FTRACE_HASH_FL_MOD));
916 }
917 
918 /* Standard output formatting function used for function return traces */
919 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
920 
921 /* Flag options */
922 #define TRACE_GRAPH_PRINT_OVERRUN       0x1
923 #define TRACE_GRAPH_PRINT_CPU           0x2
924 #define TRACE_GRAPH_PRINT_OVERHEAD      0x4
925 #define TRACE_GRAPH_PRINT_PROC          0x8
926 #define TRACE_GRAPH_PRINT_DURATION      0x10
927 #define TRACE_GRAPH_PRINT_ABS_TIME      0x20
928 #define TRACE_GRAPH_PRINT_REL_TIME      0x40
929 #define TRACE_GRAPH_PRINT_IRQS          0x80
930 #define TRACE_GRAPH_PRINT_TAIL          0x100
931 #define TRACE_GRAPH_SLEEP_TIME          0x200
932 #define TRACE_GRAPH_GRAPH_TIME          0x400
933 #define TRACE_GRAPH_PRINT_RETVAL        0x800
934 #define TRACE_GRAPH_PRINT_RETVAL_HEX    0x1000
935 #define TRACE_GRAPH_PRINT_RETADDR       0x2000
936 #define TRACE_GRAPH_ARGS		0x4000
937 #define TRACE_GRAPH_PRINT_FILL_SHIFT	28
938 #define TRACE_GRAPH_PRINT_FILL_MASK	(0x3 << TRACE_GRAPH_PRINT_FILL_SHIFT)
939 
940 extern void ftrace_graph_sleep_time_control(bool enable);
941 
942 #ifdef CONFIG_FUNCTION_PROFILER
943 extern void ftrace_graph_graph_time_control(bool enable);
944 #else
945 static inline void ftrace_graph_graph_time_control(bool enable) { }
946 #endif
947 
948 extern enum print_line_t
949 print_graph_function_flags(struct trace_iterator *iter, u32 flags);
950 extern void print_graph_headers_flags(struct seq_file *s, u32 flags);
951 extern void
952 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
953 extern void graph_trace_open(struct trace_iterator *iter);
954 extern void graph_trace_close(struct trace_iterator *iter);
955 extern int __trace_graph_entry(struct trace_array *tr,
956 			       struct ftrace_graph_ent *trace,
957 			       unsigned int trace_ctx);
958 extern int __trace_graph_retaddr_entry(struct trace_array *tr,
959 				struct ftrace_graph_ent *trace,
960 				unsigned int trace_ctx,
961 				unsigned long retaddr);
962 extern void __trace_graph_return(struct trace_array *tr,
963 				 struct ftrace_graph_ret *trace,
964 				 unsigned int trace_ctx,
965 				 u64 calltime, u64 rettime);
966 
967 extern void init_array_fgraph_ops(struct trace_array *tr, struct ftrace_ops *ops);
968 extern int allocate_fgraph_ops(struct trace_array *tr, struct ftrace_ops *ops);
969 extern void free_fgraph_ops(struct trace_array *tr);
970 
971 enum {
972 	TRACE_GRAPH_FL		= 1,
973 
974 	/*
975 	 * In the very unlikely case that an interrupt came in
976 	 * at a start of graph tracing, and we want to trace
977 	 * the function in that interrupt, the depth can be greater
978 	 * than zero, because of the preempted start of a previous
979 	 * trace. In an even more unlikely case, depth could be 2
980 	 * if a softirq interrupted the start of graph tracing,
981 	 * followed by an interrupt preempting a start of graph
982 	 * tracing in the softirq, and depth can even be 3
983 	 * if an NMI came in at the start of an interrupt function
984 	 * that preempted a softirq start of a function that
985 	 * preempted normal context!!!! Luckily, it can't be
986 	 * greater than 3, so the next two bits are a mask
987 	 * of what the depth is when we set TRACE_GRAPH_FL
988 	 */
989 
990 	TRACE_GRAPH_DEPTH_START_BIT,
991 	TRACE_GRAPH_DEPTH_END_BIT,
992 
993 	/*
994 	 * To implement set_graph_notrace, if this bit is set, we ignore
995 	 * function graph tracing of called functions, until the return
996 	 * function is called to clear it.
997 	 */
998 	TRACE_GRAPH_NOTRACE_BIT,
999 };
1000 
1001 #define TRACE_GRAPH_NOTRACE		(1 << TRACE_GRAPH_NOTRACE_BIT)
1002 
1003 static inline unsigned long ftrace_graph_depth(unsigned long *task_var)
1004 {
1005 	return (*task_var >> TRACE_GRAPH_DEPTH_START_BIT) & 3;
1006 }
1007 
1008 static inline void ftrace_graph_set_depth(unsigned long *task_var, int depth)
1009 {
1010 	*task_var &= ~(3 << TRACE_GRAPH_DEPTH_START_BIT);
1011 	*task_var |= (depth & 3) << TRACE_GRAPH_DEPTH_START_BIT;
1012 }
1013 
1014 #ifdef CONFIG_DYNAMIC_FTRACE
1015 extern struct ftrace_hash __rcu *ftrace_graph_hash;
1016 extern struct ftrace_hash __rcu *ftrace_graph_notrace_hash;
1017 
1018 static inline int
1019 ftrace_graph_addr(unsigned long *task_var, struct ftrace_graph_ent *trace)
1020 {
1021 	unsigned long addr = trace->func;
1022 	int ret = 0;
1023 	struct ftrace_hash *hash;
1024 
1025 	preempt_disable_notrace();
1026 
1027 	/*
1028 	 * Have to open code "rcu_dereference_sched()" because the
1029 	 * function graph tracer can be called when RCU is not
1030 	 * "watching".
1031 	 * Protected with schedule_on_each_cpu(ftrace_sync)
1032 	 */
1033 	hash = rcu_dereference_protected(ftrace_graph_hash, !preemptible());
1034 
1035 	if (ftrace_hash_empty(hash)) {
1036 		ret = 1;
1037 		goto out;
1038 	}
1039 
1040 	if (ftrace_lookup_ip(hash, addr)) {
1041 		/*
1042 		 * This needs to be cleared on the return functions
1043 		 * when the depth is zero.
1044 		 */
1045 		*task_var |= TRACE_GRAPH_FL;
1046 		ftrace_graph_set_depth(task_var, trace->depth);
1047 
1048 		/*
1049 		 * If no irqs are to be traced, but a set_graph_function
1050 		 * is set, and called by an interrupt handler, we still
1051 		 * want to trace it.
1052 		 */
1053 		if (in_hardirq())
1054 			trace_recursion_set(TRACE_IRQ_BIT);
1055 		else
1056 			trace_recursion_clear(TRACE_IRQ_BIT);
1057 		ret = 1;
1058 	}
1059 
1060 out:
1061 	preempt_enable_notrace();
1062 	return ret;
1063 }
1064 
1065 static inline void
1066 ftrace_graph_addr_finish(struct fgraph_ops *gops, struct ftrace_graph_ret *trace)
1067 {
1068 	unsigned long *task_var = fgraph_get_task_var(gops);
1069 
1070 	if ((*task_var & TRACE_GRAPH_FL) &&
1071 	    trace->depth == ftrace_graph_depth(task_var))
1072 		*task_var &= ~TRACE_GRAPH_FL;
1073 }
1074 
1075 static inline int ftrace_graph_notrace_addr(unsigned long addr)
1076 {
1077 	int ret = 0;
1078 	struct ftrace_hash *notrace_hash;
1079 
1080 	preempt_disable_notrace();
1081 
1082 	/*
1083 	 * Have to open code "rcu_dereference_sched()" because the
1084 	 * function graph tracer can be called when RCU is not
1085 	 * "watching".
1086 	 * Protected with schedule_on_each_cpu(ftrace_sync)
1087 	 */
1088 	notrace_hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
1089 						 !preemptible());
1090 
1091 	if (ftrace_lookup_ip(notrace_hash, addr))
1092 		ret = 1;
1093 
1094 	preempt_enable_notrace();
1095 	return ret;
1096 }
1097 #else
1098 static inline int ftrace_graph_addr(unsigned long *task_var, struct ftrace_graph_ent *trace)
1099 {
1100 	return 1;
1101 }
1102 
1103 static inline int ftrace_graph_notrace_addr(unsigned long addr)
1104 {
1105 	return 0;
1106 }
1107 static inline void ftrace_graph_addr_finish(struct fgraph_ops *gops, struct ftrace_graph_ret *trace)
1108 { }
1109 #endif /* CONFIG_DYNAMIC_FTRACE */
1110 
1111 extern unsigned int fgraph_max_depth;
1112 extern bool fgraph_sleep_time;
1113 
1114 static inline bool
1115 ftrace_graph_ignore_func(struct fgraph_ops *gops, struct ftrace_graph_ent *trace)
1116 {
1117 	unsigned long *task_var = fgraph_get_task_var(gops);
1118 
1119 	/* trace it when it is-nested-in or is a function enabled. */
1120 	return !((*task_var & TRACE_GRAPH_FL) ||
1121 		 ftrace_graph_addr(task_var, trace)) ||
1122 		(trace->depth < 0) ||
1123 		(fgraph_max_depth && trace->depth >= fgraph_max_depth);
1124 }
1125 
1126 void fgraph_init_ops(struct ftrace_ops *dst_ops,
1127 		     struct ftrace_ops *src_ops);
1128 
1129 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
1130 static inline enum print_line_t
1131 print_graph_function_flags(struct trace_iterator *iter, u32 flags)
1132 {
1133 	return TRACE_TYPE_UNHANDLED;
1134 }
1135 static inline void free_fgraph_ops(struct trace_array *tr) { }
1136 /* ftrace_ops may not be defined */
1137 #define init_array_fgraph_ops(tr, ops) do { } while (0)
1138 #define allocate_fgraph_ops(tr, ops) ({ 0; })
1139 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
1140 
1141 extern struct list_head ftrace_pids;
1142 
1143 #ifdef CONFIG_FUNCTION_TRACER
1144 
1145 #define FTRACE_PID_IGNORE	-1
1146 #define FTRACE_PID_TRACE	-2
1147 
1148 struct ftrace_func_command {
1149 	struct list_head	list;
1150 	char			*name;
1151 	int			(*func)(struct trace_array *tr,
1152 					struct ftrace_hash *hash,
1153 					char *func, char *cmd,
1154 					char *params, int enable);
1155 };
1156 extern bool ftrace_filter_param __initdata;
1157 static inline int ftrace_trace_task(struct trace_array *tr)
1158 {
1159 	return this_cpu_read(tr->array_buffer.data->ftrace_ignore_pid) !=
1160 		FTRACE_PID_IGNORE;
1161 }
1162 extern int ftrace_is_dead(void);
1163 int ftrace_create_function_files(struct trace_array *tr,
1164 				 struct dentry *parent);
1165 void ftrace_destroy_function_files(struct trace_array *tr);
1166 int ftrace_allocate_ftrace_ops(struct trace_array *tr);
1167 void ftrace_free_ftrace_ops(struct trace_array *tr);
1168 void ftrace_init_global_array_ops(struct trace_array *tr);
1169 struct trace_array *trace_get_global_array(void);
1170 void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func);
1171 void ftrace_reset_array_ops(struct trace_array *tr);
1172 void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer);
1173 void ftrace_init_tracefs_toplevel(struct trace_array *tr,
1174 				  struct dentry *d_tracer);
1175 void ftrace_clear_pids(struct trace_array *tr);
1176 int init_function_trace(void);
1177 void ftrace_pid_follow_fork(struct trace_array *tr, bool enable);
1178 #else
1179 static inline int ftrace_trace_task(struct trace_array *tr)
1180 {
1181 	return 1;
1182 }
1183 static inline int ftrace_is_dead(void) { return 0; }
1184 static inline int
1185 ftrace_create_function_files(struct trace_array *tr,
1186 			     struct dentry *parent)
1187 {
1188 	return 0;
1189 }
1190 static inline int ftrace_allocate_ftrace_ops(struct trace_array *tr)
1191 {
1192 	return 0;
1193 }
1194 static inline void ftrace_free_ftrace_ops(struct trace_array *tr) { }
1195 static inline void ftrace_destroy_function_files(struct trace_array *tr) { }
1196 static inline __init void
1197 ftrace_init_global_array_ops(struct trace_array *tr) { }
1198 static inline void ftrace_reset_array_ops(struct trace_array *tr) { }
1199 static inline void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d) { }
1200 static inline void ftrace_init_tracefs_toplevel(struct trace_array *tr, struct dentry *d) { }
1201 static inline void ftrace_clear_pids(struct trace_array *tr) { }
1202 static inline int init_function_trace(void) { return 0; }
1203 static inline void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) { }
1204 /* ftace_func_t type is not defined, use macro instead of static inline */
1205 #define ftrace_init_array_ops(tr, func) do { } while (0)
1206 #endif /* CONFIG_FUNCTION_TRACER */
1207 
1208 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
1209 
1210 struct ftrace_probe_ops {
1211 	void			(*func)(unsigned long ip,
1212 					unsigned long parent_ip,
1213 					struct trace_array *tr,
1214 					struct ftrace_probe_ops *ops,
1215 					void *data);
1216 	int			(*init)(struct ftrace_probe_ops *ops,
1217 					struct trace_array *tr,
1218 					unsigned long ip, void *init_data,
1219 					void **data);
1220 	void			(*free)(struct ftrace_probe_ops *ops,
1221 					struct trace_array *tr,
1222 					unsigned long ip, void *data);
1223 	int			(*print)(struct seq_file *m,
1224 					 unsigned long ip,
1225 					 struct ftrace_probe_ops *ops,
1226 					 void *data);
1227 };
1228 
1229 struct ftrace_func_mapper;
1230 typedef int (*ftrace_mapper_func)(void *data);
1231 
1232 struct ftrace_func_mapper *allocate_ftrace_func_mapper(void);
1233 void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
1234 					   unsigned long ip);
1235 int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
1236 			       unsigned long ip, void *data);
1237 void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
1238 				   unsigned long ip);
1239 void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
1240 			     ftrace_mapper_func free_func);
1241 
1242 extern int
1243 register_ftrace_function_probe(char *glob, struct trace_array *tr,
1244 			       struct ftrace_probe_ops *ops, void *data);
1245 extern int
1246 unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
1247 				      struct ftrace_probe_ops *ops);
1248 extern void clear_ftrace_function_probes(struct trace_array *tr);
1249 
1250 int register_ftrace_command(struct ftrace_func_command *cmd);
1251 int unregister_ftrace_command(struct ftrace_func_command *cmd);
1252 
1253 void ftrace_create_filter_files(struct ftrace_ops *ops,
1254 				struct dentry *parent);
1255 void ftrace_destroy_filter_files(struct ftrace_ops *ops);
1256 
1257 extern int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
1258 			     int len, int reset);
1259 extern int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
1260 			      int len, int reset);
1261 #else
1262 struct ftrace_func_command;
1263 
1264 static inline __init int register_ftrace_command(struct ftrace_func_command *cmd)
1265 {
1266 	return -EINVAL;
1267 }
1268 static inline __init int unregister_ftrace_command(char *cmd_name)
1269 {
1270 	return -EINVAL;
1271 }
1272 static inline void clear_ftrace_function_probes(struct trace_array *tr)
1273 {
1274 }
1275 
1276 /*
1277  * The ops parameter passed in is usually undefined.
1278  * This must be a macro.
1279  */
1280 #define ftrace_create_filter_files(ops, parent) do { } while (0)
1281 #define ftrace_destroy_filter_files(ops) do { } while (0)
1282 #endif /* CONFIG_FUNCTION_TRACER && CONFIG_DYNAMIC_FTRACE */
1283 
1284 bool ftrace_event_is_function(struct trace_event_call *call);
1285 
1286 /*
1287  * struct trace_parser - servers for reading the user input separated by spaces
1288  * @cont: set if the input is not complete - no final space char was found
1289  * @buffer: holds the parsed user input
1290  * @idx: user input length
1291  * @size: buffer size
1292  */
1293 struct trace_parser {
1294 	bool		cont;
1295 	char		*buffer;
1296 	unsigned	idx;
1297 	unsigned	size;
1298 };
1299 
1300 static inline bool trace_parser_loaded(struct trace_parser *parser)
1301 {
1302 	return (parser->idx != 0);
1303 }
1304 
1305 static inline bool trace_parser_cont(struct trace_parser *parser)
1306 {
1307 	return parser->cont;
1308 }
1309 
1310 static inline void trace_parser_clear(struct trace_parser *parser)
1311 {
1312 	parser->cont = false;
1313 	parser->idx = 0;
1314 }
1315 
1316 extern int trace_parser_get_init(struct trace_parser *parser, int size);
1317 extern void trace_parser_put(struct trace_parser *parser);
1318 extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
1319 	size_t cnt, loff_t *ppos);
1320 
1321 /*
1322  * Only create function graph options if function graph is configured.
1323  */
1324 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1325 # define FGRAPH_FLAGS						\
1326 		C(DISPLAY_GRAPH,	"display-graph"),
1327 #else
1328 # define FGRAPH_FLAGS
1329 #endif
1330 
1331 #ifdef CONFIG_BRANCH_TRACER
1332 # define BRANCH_FLAGS					\
1333 		C(BRANCH,		"branch"),
1334 #else
1335 # define BRANCH_FLAGS
1336 #endif
1337 
1338 #ifdef CONFIG_FUNCTION_TRACER
1339 # define FUNCTION_FLAGS						\
1340 		C(FUNCTION,		"function-trace"),	\
1341 		C(FUNC_FORK,		"function-fork"),
1342 # define FUNCTION_DEFAULT_FLAGS		TRACE_ITER_FUNCTION
1343 #else
1344 # define FUNCTION_FLAGS
1345 # define FUNCTION_DEFAULT_FLAGS		0UL
1346 # define TRACE_ITER_FUNC_FORK		0UL
1347 #endif
1348 
1349 #ifdef CONFIG_STACKTRACE
1350 # define STACK_FLAGS				\
1351 		C(STACKTRACE,		"stacktrace"),
1352 #else
1353 # define STACK_FLAGS
1354 #endif
1355 
1356 /*
1357  * trace_iterator_flags is an enumeration that defines bit
1358  * positions into trace_flags that controls the output.
1359  *
1360  * NOTE: These bits must match the trace_options array in
1361  *       trace.c (this macro guarantees it).
1362  */
1363 #define TRACE_FLAGS						\
1364 		C(PRINT_PARENT,		"print-parent"),	\
1365 		C(SYM_OFFSET,		"sym-offset"),		\
1366 		C(SYM_ADDR,		"sym-addr"),		\
1367 		C(VERBOSE,		"verbose"),		\
1368 		C(RAW,			"raw"),			\
1369 		C(HEX,			"hex"),			\
1370 		C(BIN,			"bin"),			\
1371 		C(BLOCK,		"block"),		\
1372 		C(FIELDS,		"fields"),		\
1373 		C(PRINTK,		"trace_printk"),	\
1374 		C(ANNOTATE,		"annotate"),		\
1375 		C(USERSTACKTRACE,	"userstacktrace"),	\
1376 		C(SYM_USEROBJ,		"sym-userobj"),		\
1377 		C(PRINTK_MSGONLY,	"printk-msg-only"),	\
1378 		C(CONTEXT_INFO,		"context-info"),   /* Print pid/cpu/time */ \
1379 		C(LATENCY_FMT,		"latency-format"),	\
1380 		C(RECORD_CMD,		"record-cmd"),		\
1381 		C(RECORD_TGID,		"record-tgid"),		\
1382 		C(OVERWRITE,		"overwrite"),		\
1383 		C(STOP_ON_FREE,		"disable_on_free"),	\
1384 		C(IRQ_INFO,		"irq-info"),		\
1385 		C(MARKERS,		"markers"),		\
1386 		C(EVENT_FORK,		"event-fork"),		\
1387 		C(TRACE_PRINTK,		"trace_printk_dest"),	\
1388 		C(COPY_MARKER,		"copy_trace_marker"),\
1389 		C(PAUSE_ON_TRACE,	"pause-on-trace"),	\
1390 		C(HASH_PTR,		"hash-ptr"),	/* Print hashed pointer */ \
1391 		FUNCTION_FLAGS					\
1392 		FGRAPH_FLAGS					\
1393 		STACK_FLAGS					\
1394 		BRANCH_FLAGS
1395 
1396 /*
1397  * By defining C, we can make TRACE_FLAGS a list of bit names
1398  * that will define the bits for the flag masks.
1399  */
1400 #undef C
1401 #define C(a, b) TRACE_ITER_##a##_BIT
1402 
1403 enum trace_iterator_bits {
1404 	TRACE_FLAGS
1405 	/* Make sure we don't go more than we have bits for */
1406 	TRACE_ITER_LAST_BIT
1407 };
1408 
1409 /*
1410  * By redefining C, we can make TRACE_FLAGS a list of masks that
1411  * use the bits as defined above.
1412  */
1413 #undef C
1414 #define C(a, b) TRACE_ITER_##a = (1 << TRACE_ITER_##a##_BIT)
1415 
1416 enum trace_iterator_flags { TRACE_FLAGS };
1417 
1418 /*
1419  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
1420  * control the output of kernel symbols.
1421  */
1422 #define TRACE_ITER_SYM_MASK \
1423 	(TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
1424 
1425 extern struct tracer nop_trace;
1426 
1427 #ifdef CONFIG_BRANCH_TRACER
1428 extern int enable_branch_tracing(struct trace_array *tr);
1429 extern void disable_branch_tracing(void);
1430 static inline int trace_branch_enable(struct trace_array *tr)
1431 {
1432 	if (tr->trace_flags & TRACE_ITER_BRANCH)
1433 		return enable_branch_tracing(tr);
1434 	return 0;
1435 }
1436 static inline void trace_branch_disable(void)
1437 {
1438 	/* due to races, always disable */
1439 	disable_branch_tracing();
1440 }
1441 #else
1442 static inline int trace_branch_enable(struct trace_array *tr)
1443 {
1444 	return 0;
1445 }
1446 static inline void trace_branch_disable(void)
1447 {
1448 }
1449 #endif /* CONFIG_BRANCH_TRACER */
1450 
1451 /* set ring buffers to default size if not already done so */
1452 int tracing_update_buffers(struct trace_array *tr);
1453 
1454 union trace_synth_field {
1455 	u8				as_u8;
1456 	u16				as_u16;
1457 	u32				as_u32;
1458 	u64				as_u64;
1459 	struct trace_dynamic_info	as_dynamic;
1460 };
1461 
1462 struct ftrace_event_field {
1463 	struct list_head	link;
1464 	const char		*name;
1465 	const char		*type;
1466 	int			filter_type;
1467 	int			offset;
1468 	int			size;
1469 	unsigned int		is_signed:1;
1470 	unsigned int		needs_test:1;
1471 	int			len;
1472 };
1473 
1474 struct prog_entry;
1475 
1476 struct event_filter {
1477 	struct prog_entry __rcu	*prog;
1478 	char			*filter_string;
1479 };
1480 
1481 struct event_subsystem {
1482 	struct list_head	list;
1483 	const char		*name;
1484 	struct event_filter	*filter;
1485 	int			ref_count;
1486 };
1487 
1488 struct trace_subsystem_dir {
1489 	struct list_head		list;
1490 	struct event_subsystem		*subsystem;
1491 	struct trace_array		*tr;
1492 	struct eventfs_inode		*ei;
1493 	int				ref_count;
1494 	int				nr_events;
1495 };
1496 
1497 void trace_buffer_unlock_commit_regs(struct trace_array *tr,
1498 				     struct trace_buffer *buffer,
1499 				     struct ring_buffer_event *event,
1500 				     unsigned int trcace_ctx,
1501 				     struct pt_regs *regs);
1502 
1503 static inline void trace_buffer_unlock_commit(struct trace_array *tr,
1504 					      struct trace_buffer *buffer,
1505 					      struct ring_buffer_event *event,
1506 					      unsigned int trace_ctx)
1507 {
1508 	trace_buffer_unlock_commit_regs(tr, buffer, event, trace_ctx, NULL);
1509 }
1510 
1511 DECLARE_PER_CPU(bool, trace_taskinfo_save);
1512 int trace_save_cmdline(struct task_struct *tsk);
1513 int trace_create_savedcmd(void);
1514 int trace_alloc_tgid_map(void);
1515 void trace_free_saved_cmdlines_buffer(void);
1516 
1517 extern const struct file_operations tracing_saved_cmdlines_fops;
1518 extern const struct file_operations tracing_saved_tgids_fops;
1519 extern const struct file_operations tracing_saved_cmdlines_size_fops;
1520 
1521 DECLARE_PER_CPU(struct ring_buffer_event *, trace_buffered_event);
1522 DECLARE_PER_CPU(int, trace_buffered_event_cnt);
1523 void trace_buffered_event_disable(void);
1524 void trace_buffered_event_enable(void);
1525 
1526 void early_enable_events(struct trace_array *tr, char *buf, bool disable_first);
1527 
1528 static inline void
1529 __trace_event_discard_commit(struct trace_buffer *buffer,
1530 			     struct ring_buffer_event *event)
1531 {
1532 	if (this_cpu_read(trace_buffered_event) == event) {
1533 		/* Simply release the temp buffer and enable preemption */
1534 		this_cpu_dec(trace_buffered_event_cnt);
1535 		preempt_enable_notrace();
1536 		return;
1537 	}
1538 	/* ring_buffer_discard_commit() enables preemption */
1539 	ring_buffer_discard_commit(buffer, event);
1540 }
1541 
1542 /*
1543  * Helper function for event_trigger_unlock_commit{_regs}().
1544  * If there are event triggers attached to this event that requires
1545  * filtering against its fields, then they will be called as the
1546  * entry already holds the field information of the current event.
1547  *
1548  * It also checks if the event should be discarded or not.
1549  * It is to be discarded if the event is soft disabled and the
1550  * event was only recorded to process triggers, or if the event
1551  * filter is active and this event did not match the filters.
1552  *
1553  * Returns true if the event is discarded, false otherwise.
1554  */
1555 static inline bool
1556 __event_trigger_test_discard(struct trace_event_file *file,
1557 			     struct trace_buffer *buffer,
1558 			     struct ring_buffer_event *event,
1559 			     void *entry,
1560 			     enum event_trigger_type *tt)
1561 {
1562 	unsigned long eflags = file->flags;
1563 
1564 	if (eflags & EVENT_FILE_FL_TRIGGER_COND)
1565 		*tt = event_triggers_call(file, buffer, entry, event);
1566 
1567 	if (likely(!(file->flags & (EVENT_FILE_FL_SOFT_DISABLED |
1568 				    EVENT_FILE_FL_FILTERED |
1569 				    EVENT_FILE_FL_PID_FILTER))))
1570 		return false;
1571 
1572 	if (file->flags & EVENT_FILE_FL_SOFT_DISABLED)
1573 		goto discard;
1574 
1575 	if (file->flags & EVENT_FILE_FL_FILTERED &&
1576 	    !filter_match_preds(file->filter, entry))
1577 		goto discard;
1578 
1579 	if ((file->flags & EVENT_FILE_FL_PID_FILTER) &&
1580 	    trace_event_ignore_this_pid(file))
1581 		goto discard;
1582 
1583 	return false;
1584  discard:
1585 	__trace_event_discard_commit(buffer, event);
1586 	return true;
1587 }
1588 
1589 /**
1590  * event_trigger_unlock_commit - handle triggers and finish event commit
1591  * @file: The file pointer associated with the event
1592  * @buffer: The ring buffer that the event is being written to
1593  * @event: The event meta data in the ring buffer
1594  * @entry: The event itself
1595  * @trace_ctx: The tracing context flags.
1596  *
1597  * This is a helper function to handle triggers that require data
1598  * from the event itself. It also tests the event against filters and
1599  * if the event is soft disabled and should be discarded.
1600  */
1601 static inline void
1602 event_trigger_unlock_commit(struct trace_event_file *file,
1603 			    struct trace_buffer *buffer,
1604 			    struct ring_buffer_event *event,
1605 			    void *entry, unsigned int trace_ctx)
1606 {
1607 	enum event_trigger_type tt = ETT_NONE;
1608 
1609 	if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1610 		trace_buffer_unlock_commit(file->tr, buffer, event, trace_ctx);
1611 
1612 	if (tt)
1613 		event_triggers_post_call(file, tt);
1614 }
1615 
1616 #define FILTER_PRED_INVALID	((unsigned short)-1)
1617 #define FILTER_PRED_IS_RIGHT	(1 << 15)
1618 #define FILTER_PRED_FOLD	(1 << 15)
1619 
1620 /*
1621  * The max preds is the size of unsigned short with
1622  * two flags at the MSBs. One bit is used for both the IS_RIGHT
1623  * and FOLD flags. The other is reserved.
1624  *
1625  * 2^14 preds is way more than enough.
1626  */
1627 #define MAX_FILTER_PRED		16384
1628 
1629 struct filter_pred;
1630 struct regex;
1631 
1632 typedef int (*regex_match_func)(char *str, struct regex *r, int len);
1633 
1634 enum regex_type {
1635 	MATCH_FULL = 0,
1636 	MATCH_FRONT_ONLY,
1637 	MATCH_MIDDLE_ONLY,
1638 	MATCH_END_ONLY,
1639 	MATCH_GLOB,
1640 	MATCH_INDEX,
1641 };
1642 
1643 struct regex {
1644 	char			pattern[MAX_FILTER_STR_VAL];
1645 	int			len;
1646 	int			field_len;
1647 	regex_match_func	match;
1648 };
1649 
1650 static inline bool is_string_field(struct ftrace_event_field *field)
1651 {
1652 	return field->filter_type == FILTER_DYN_STRING ||
1653 	       field->filter_type == FILTER_RDYN_STRING ||
1654 	       field->filter_type == FILTER_STATIC_STRING ||
1655 	       field->filter_type == FILTER_PTR_STRING ||
1656 	       field->filter_type == FILTER_COMM;
1657 }
1658 
1659 static inline bool is_function_field(struct ftrace_event_field *field)
1660 {
1661 	return field->filter_type == FILTER_TRACE_FN;
1662 }
1663 
1664 extern enum regex_type
1665 filter_parse_regex(char *buff, int len, char **search, int *not);
1666 extern void print_event_filter(struct trace_event_file *file,
1667 			       struct trace_seq *s);
1668 extern int apply_event_filter(struct trace_event_file *file,
1669 			      char *filter_string);
1670 extern int apply_subsystem_event_filter(struct trace_subsystem_dir *dir,
1671 					char *filter_string);
1672 extern void print_subsystem_event_filter(struct event_subsystem *system,
1673 					 struct trace_seq *s);
1674 extern int filter_assign_type(const char *type);
1675 extern int create_event_filter(struct trace_array *tr,
1676 			       struct trace_event_call *call,
1677 			       char *filter_str, bool set_str,
1678 			       struct event_filter **filterp);
1679 extern void free_event_filter(struct event_filter *filter);
1680 
1681 struct ftrace_event_field *
1682 trace_find_event_field(struct trace_event_call *call, char *name);
1683 
1684 extern void trace_event_enable_cmd_record(bool enable);
1685 extern void trace_event_enable_tgid_record(bool enable);
1686 
1687 extern int event_trace_init(void);
1688 extern int init_events(void);
1689 extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
1690 extern int event_trace_del_tracer(struct trace_array *tr);
1691 extern void __trace_early_add_events(struct trace_array *tr);
1692 
1693 extern struct trace_event_file *__find_event_file(struct trace_array *tr,
1694 						  const char *system,
1695 						  const char *event);
1696 extern struct trace_event_file *find_event_file(struct trace_array *tr,
1697 						const char *system,
1698 						const char *event);
1699 
1700 static inline void *event_file_data(struct file *filp)
1701 {
1702 	return READ_ONCE(file_inode(filp)->i_private);
1703 }
1704 
1705 extern struct mutex event_mutex;
1706 extern struct list_head ftrace_events;
1707 
1708 /*
1709  * When the trace_event_file is the filp->i_private pointer,
1710  * it must be taken under the event_mutex lock, and then checked
1711  * if the EVENT_FILE_FL_FREED flag is set. If it is, then the
1712  * data pointed to by the trace_event_file can not be trusted.
1713  *
1714  * Use the event_file_file() to access the trace_event_file from
1715  * the filp the first time under the event_mutex and check for
1716  * NULL. If it is needed to be retrieved again and the event_mutex
1717  * is still held, then the event_file_data() can be used and it
1718  * is guaranteed to be valid.
1719  */
1720 static inline struct trace_event_file *event_file_file(struct file *filp)
1721 {
1722 	struct trace_event_file *file;
1723 
1724 	lockdep_assert_held(&event_mutex);
1725 	file = READ_ONCE(file_inode(filp)->i_private);
1726 	if (!file || file->flags & EVENT_FILE_FL_FREED)
1727 		return NULL;
1728 	return file;
1729 }
1730 
1731 extern const struct file_operations event_trigger_fops;
1732 extern const struct file_operations event_hist_fops;
1733 extern const struct file_operations event_hist_debug_fops;
1734 extern const struct file_operations event_inject_fops;
1735 
1736 #ifdef CONFIG_HIST_TRIGGERS
1737 extern int register_trigger_hist_cmd(void);
1738 extern int register_trigger_hist_enable_disable_cmds(void);
1739 #else
1740 static inline int register_trigger_hist_cmd(void) { return 0; }
1741 static inline int register_trigger_hist_enable_disable_cmds(void) { return 0; }
1742 #endif
1743 
1744 extern int register_trigger_cmds(void);
1745 extern void clear_event_triggers(struct trace_array *tr);
1746 
1747 enum {
1748 	EVENT_TRIGGER_FL_PROBE		= BIT(0),
1749 };
1750 
1751 struct event_trigger_data {
1752 	unsigned long			count;
1753 	int				ref;
1754 	int				flags;
1755 	const struct event_trigger_ops	*ops;
1756 	struct event_command		*cmd_ops;
1757 	struct event_filter __rcu	*filter;
1758 	char				*filter_str;
1759 	void				*private_data;
1760 	bool				paused;
1761 	bool				paused_tmp;
1762 	struct list_head		list;
1763 	char				*name;
1764 	struct list_head		named_list;
1765 	struct event_trigger_data	*named_data;
1766 };
1767 
1768 /* Avoid typos */
1769 #define ENABLE_EVENT_STR	"enable_event"
1770 #define DISABLE_EVENT_STR	"disable_event"
1771 #define ENABLE_HIST_STR		"enable_hist"
1772 #define DISABLE_HIST_STR	"disable_hist"
1773 
1774 struct enable_trigger_data {
1775 	struct trace_event_file		*file;
1776 	bool				enable;
1777 	bool				hist;
1778 };
1779 
1780 extern int event_enable_trigger_print(struct seq_file *m,
1781 				      struct event_trigger_data *data);
1782 extern void event_enable_trigger_free(struct event_trigger_data *data);
1783 extern int event_enable_trigger_parse(struct event_command *cmd_ops,
1784 				      struct trace_event_file *file,
1785 				      char *glob, char *cmd,
1786 				      char *param_and_filter);
1787 extern int event_enable_register_trigger(char *glob,
1788 					 struct event_trigger_data *data,
1789 					 struct trace_event_file *file);
1790 extern void event_enable_unregister_trigger(char *glob,
1791 					    struct event_trigger_data *test,
1792 					    struct trace_event_file *file);
1793 extern struct event_trigger_data *
1794 trigger_data_alloc(struct event_command *cmd_ops, char *cmd, char *param,
1795 		   void *private_data);
1796 extern void trigger_data_free(struct event_trigger_data *data);
1797 extern int event_trigger_init(struct event_trigger_data *data);
1798 extern int trace_event_trigger_enable_disable(struct trace_event_file *file,
1799 					      int trigger_enable);
1800 extern void update_cond_flag(struct trace_event_file *file);
1801 extern int set_trigger_filter(char *filter_str,
1802 			      struct event_trigger_data *trigger_data,
1803 			      struct trace_event_file *file);
1804 extern struct event_trigger_data *find_named_trigger(const char *name);
1805 extern bool is_named_trigger(struct event_trigger_data *test);
1806 extern int save_named_trigger(const char *name,
1807 			      struct event_trigger_data *data);
1808 extern void del_named_trigger(struct event_trigger_data *data);
1809 extern void pause_named_trigger(struct event_trigger_data *data);
1810 extern void unpause_named_trigger(struct event_trigger_data *data);
1811 extern void set_named_trigger_data(struct event_trigger_data *data,
1812 				   struct event_trigger_data *named_data);
1813 extern struct event_trigger_data *
1814 get_named_trigger_data(struct event_trigger_data *data);
1815 extern int register_event_command(struct event_command *cmd);
1816 extern int unregister_event_command(struct event_command *cmd);
1817 extern int register_trigger_hist_enable_disable_cmds(void);
1818 extern bool event_trigger_check_remove(const char *glob);
1819 extern bool event_trigger_empty_param(const char *param);
1820 extern int event_trigger_separate_filter(char *param_and_filter, char **param,
1821 					 char **filter, bool param_required);
1822 extern int event_trigger_parse_num(char *trigger,
1823 				   struct event_trigger_data *trigger_data);
1824 extern int event_trigger_set_filter(struct event_command *cmd_ops,
1825 				    struct trace_event_file *file,
1826 				    char *param,
1827 				    struct event_trigger_data *trigger_data);
1828 extern void event_trigger_reset_filter(struct event_command *cmd_ops,
1829 				       struct event_trigger_data *trigger_data);
1830 extern int event_trigger_register(struct event_command *cmd_ops,
1831 				  struct trace_event_file *file,
1832 				  char *glob,
1833 				  struct event_trigger_data *trigger_data);
1834 extern void event_trigger_unregister(struct event_command *cmd_ops,
1835 				     struct trace_event_file *file,
1836 				     char *glob,
1837 				     struct event_trigger_data *trigger_data);
1838 
1839 extern void event_file_get(struct trace_event_file *file);
1840 extern void event_file_put(struct trace_event_file *file);
1841 
1842 /**
1843  * struct event_trigger_ops - callbacks for trace event triggers
1844  *
1845  * The methods in this structure provide per-event trigger hooks for
1846  * various trigger operations.
1847  *
1848  * The @init and @free methods are used during trigger setup and
1849  * teardown, typically called from an event_command's @parse()
1850  * function implementation.
1851  *
1852  * The @print method is used to print the trigger spec.
1853  *
1854  * The @trigger method is the function that actually implements the
1855  * trigger and is called in the context of the triggering event
1856  * whenever that event occurs.
1857  *
1858  * All the methods below, except for @init() and @free(), must be
1859  * implemented.
1860  *
1861  * @trigger: The trigger 'probe' function called when the triggering
1862  *	event occurs.  The data passed into this callback is the data
1863  *	that was supplied to the event_command @reg() function that
1864  *	registered the trigger (see struct event_command) along with
1865  *	the trace record, rec.
1866  *
1867  * @init: An optional initialization function called for the trigger
1868  *	when the trigger is registered (via the event_command reg()
1869  *	function).  This can be used to perform per-trigger
1870  *	initialization such as incrementing a per-trigger reference
1871  *	count, for instance.  This is usually implemented by the
1872  *	generic utility function @event_trigger_init() (see
1873  *	trace_event_triggers.c).
1874  *
1875  * @free: An optional de-initialization function called for the
1876  *	trigger when the trigger is unregistered (via the
1877  *	event_command @reg() function).  This can be used to perform
1878  *	per-trigger de-initialization such as decrementing a
1879  *	per-trigger reference count and freeing corresponding trigger
1880  *	data, for instance.  This is usually implemented by the
1881  *	generic utility function @event_trigger_free() (see
1882  *	trace_event_triggers.c).
1883  *
1884  * @print: The callback function invoked to have the trigger print
1885  *	itself.  This is usually implemented by a wrapper function
1886  *	that calls the generic utility function @event_trigger_print()
1887  *	(see trace_event_triggers.c).
1888  */
1889 struct event_trigger_ops {
1890 	void			(*trigger)(struct event_trigger_data *data,
1891 					   struct trace_buffer *buffer,
1892 					   void *rec,
1893 					   struct ring_buffer_event *rbe);
1894 	int			(*init)(struct event_trigger_data *data);
1895 	void			(*free)(struct event_trigger_data *data);
1896 	int			(*print)(struct seq_file *m,
1897 					 struct event_trigger_data *data);
1898 };
1899 
1900 /**
1901  * struct event_command - callbacks and data members for event commands
1902  *
1903  * Event commands are invoked by users by writing the command name
1904  * into the 'trigger' file associated with a trace event.  The
1905  * parameters associated with a specific invocation of an event
1906  * command are used to create an event trigger instance, which is
1907  * added to the list of trigger instances associated with that trace
1908  * event.  When the event is hit, the set of triggers associated with
1909  * that event is invoked.
1910  *
1911  * The data members in this structure provide per-event command data
1912  * for various event commands.
1913  *
1914  * All the data members below, except for @post_trigger, must be set
1915  * for each event command.
1916  *
1917  * @name: The unique name that identifies the event command.  This is
1918  *	the name used when setting triggers via trigger files.
1919  *
1920  * @trigger_type: A unique id that identifies the event command
1921  *	'type'.  This value has two purposes, the first to ensure that
1922  *	only one trigger of the same type can be set at a given time
1923  *	for a particular event e.g. it doesn't make sense to have both
1924  *	a traceon and traceoff trigger attached to a single event at
1925  *	the same time, so traceon and traceoff have the same type
1926  *	though they have different names.  The @trigger_type value is
1927  *	also used as a bit value for deferring the actual trigger
1928  *	action until after the current event is finished.  Some
1929  *	commands need to do this if they themselves log to the trace
1930  *	buffer (see the @post_trigger() member below).  @trigger_type
1931  *	values are defined by adding new values to the trigger_type
1932  *	enum in include/linux/trace_events.h.
1933  *
1934  * @flags: See the enum event_command_flags below.
1935  *
1936  * All the methods below, except for @set_filter() and @unreg_all(),
1937  * must be implemented.
1938  *
1939  * @parse: The callback function responsible for parsing and
1940  *	registering the trigger written to the 'trigger' file by the
1941  *	user.  It allocates the trigger instance and registers it with
1942  *	the appropriate trace event.  It makes use of the other
1943  *	event_command callback functions to orchestrate this, and is
1944  *	usually implemented by the generic utility function
1945  *	@event_trigger_callback() (see trace_event_triggers.c).
1946  *
1947  * @reg: Adds the trigger to the list of triggers associated with the
1948  *	event, and enables the event trigger itself, after
1949  *	initializing it (via the event_trigger_ops @init() function).
1950  *	This is also where commands can use the @trigger_type value to
1951  *	make the decision as to whether or not multiple instances of
1952  *	the trigger should be allowed.  This is usually implemented by
1953  *	the generic utility function @register_trigger() (see
1954  *	trace_event_triggers.c).
1955  *
1956  * @unreg: Removes the trigger from the list of triggers associated
1957  *	with the event, and disables the event trigger itself, after
1958  *	initializing it (via the event_trigger_ops @free() function).
1959  *	This is usually implemented by the generic utility function
1960  *	@unregister_trigger() (see trace_event_triggers.c).
1961  *
1962  * @unreg_all: An optional function called to remove all the triggers
1963  *	from the list of triggers associated with the event.  Called
1964  *	when a trigger file is opened in truncate mode.
1965  *
1966  * @set_filter: An optional function called to parse and set a filter
1967  *	for the trigger.  If no @set_filter() method is set for the
1968  *	event command, filters set by the user for the command will be
1969  *	ignored.  This is usually implemented by the generic utility
1970  *	function @set_trigger_filter() (see trace_event_triggers.c).
1971  *
1972  * @get_trigger_ops: The callback function invoked to retrieve the
1973  *	event_trigger_ops implementation associated with the command.
1974  *	This callback function allows a single event_command to
1975  *	support multiple trigger implementations via different sets of
1976  *	event_trigger_ops, depending on the value of the @param
1977  *	string.
1978  */
1979 struct event_command {
1980 	struct list_head	list;
1981 	char			*name;
1982 	enum event_trigger_type	trigger_type;
1983 	int			flags;
1984 	int			(*parse)(struct event_command *cmd_ops,
1985 					 struct trace_event_file *file,
1986 					 char *glob, char *cmd,
1987 					 char *param_and_filter);
1988 	int			(*reg)(char *glob,
1989 				       struct event_trigger_data *data,
1990 				       struct trace_event_file *file);
1991 	void			(*unreg)(char *glob,
1992 					 struct event_trigger_data *data,
1993 					 struct trace_event_file *file);
1994 	void			(*unreg_all)(struct trace_event_file *file);
1995 	int			(*set_filter)(char *filter_str,
1996 					      struct event_trigger_data *data,
1997 					      struct trace_event_file *file);
1998 	const struct event_trigger_ops *(*get_trigger_ops)(char *cmd, char *param);
1999 };
2000 
2001 /**
2002  * enum event_command_flags - flags for struct event_command
2003  *
2004  * @POST_TRIGGER: A flag that says whether or not this command needs
2005  *	to have its action delayed until after the current event has
2006  *	been closed.  Some triggers need to avoid being invoked while
2007  *	an event is currently in the process of being logged, since
2008  *	the trigger may itself log data into the trace buffer.  Thus
2009  *	we make sure the current event is committed before invoking
2010  *	those triggers.  To do that, the trigger invocation is split
2011  *	in two - the first part checks the filter using the current
2012  *	trace record; if a command has the @post_trigger flag set, it
2013  *	sets a bit for itself in the return value, otherwise it
2014  *	directly invokes the trigger.  Once all commands have been
2015  *	either invoked or set their return flag, the current record is
2016  *	either committed or discarded.  At that point, if any commands
2017  *	have deferred their triggers, those commands are finally
2018  *	invoked following the close of the current event.  In other
2019  *	words, if the event_trigger_ops @func() probe implementation
2020  *	itself logs to the trace buffer, this flag should be set,
2021  *	otherwise it can be left unspecified.
2022  *
2023  * @NEEDS_REC: A flag that says whether or not this command needs
2024  *	access to the trace record in order to perform its function,
2025  *	regardless of whether or not it has a filter associated with
2026  *	it (filters make a trigger require access to the trace record
2027  *	but are not always present).
2028  */
2029 enum event_command_flags {
2030 	EVENT_CMD_FL_POST_TRIGGER	= 1,
2031 	EVENT_CMD_FL_NEEDS_REC		= 2,
2032 };
2033 
2034 static inline bool event_command_post_trigger(struct event_command *cmd_ops)
2035 {
2036 	return cmd_ops->flags & EVENT_CMD_FL_POST_TRIGGER;
2037 }
2038 
2039 static inline bool event_command_needs_rec(struct event_command *cmd_ops)
2040 {
2041 	return cmd_ops->flags & EVENT_CMD_FL_NEEDS_REC;
2042 }
2043 
2044 extern int trace_event_enable_disable(struct trace_event_file *file,
2045 				      int enable, int soft_disable);
2046 extern int tracing_alloc_snapshot(void);
2047 extern void tracing_snapshot_cond(struct trace_array *tr, void *cond_data);
2048 extern int tracing_snapshot_cond_enable(struct trace_array *tr, void *cond_data, cond_update_fn_t update);
2049 
2050 extern int tracing_snapshot_cond_disable(struct trace_array *tr);
2051 extern void *tracing_cond_snapshot_data(struct trace_array *tr);
2052 
2053 extern const char *__start___trace_bprintk_fmt[];
2054 extern const char *__stop___trace_bprintk_fmt[];
2055 
2056 extern const char *__start___tracepoint_str[];
2057 extern const char *__stop___tracepoint_str[];
2058 
2059 void trace_printk_control(bool enabled);
2060 void trace_printk_start_comm(void);
2061 int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set);
2062 int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled);
2063 
2064 /* Used from boot time tracer */
2065 extern int trace_set_options(struct trace_array *tr, char *option);
2066 extern int tracing_set_tracer(struct trace_array *tr, const char *buf);
2067 extern ssize_t tracing_resize_ring_buffer(struct trace_array *tr,
2068 					  unsigned long size, int cpu_id);
2069 extern int tracing_set_cpumask(struct trace_array *tr,
2070 				cpumask_var_t tracing_cpumask_new);
2071 
2072 
2073 #define MAX_EVENT_NAME_LEN	64
2074 
2075 extern ssize_t trace_parse_run_command(struct file *file,
2076 		const char __user *buffer, size_t count, loff_t *ppos,
2077 		int (*createfn)(const char *));
2078 
2079 extern unsigned int err_pos(char *cmd, const char *str);
2080 extern void tracing_log_err(struct trace_array *tr,
2081 			    const char *loc, const char *cmd,
2082 			    const char **errs, u8 type, u16 pos);
2083 
2084 /*
2085  * Normal trace_printk() and friends allocates special buffers
2086  * to do the manipulation, as well as saves the print formats
2087  * into sections to display. But the trace infrastructure wants
2088  * to use these without the added overhead at the price of being
2089  * a bit slower (used mainly for warnings, where we don't care
2090  * about performance). The internal_trace_puts() is for such
2091  * a purpose.
2092  */
2093 #define internal_trace_puts(str) __trace_puts(_THIS_IP_, str, strlen(str))
2094 
2095 #undef FTRACE_ENTRY
2096 #define FTRACE_ENTRY(call, struct_name, id, tstruct, print)	\
2097 	extern struct trace_event_call					\
2098 	__aligned(4) event_##call;
2099 #undef FTRACE_ENTRY_DUP
2100 #define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print)	\
2101 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
2102 #undef FTRACE_ENTRY_PACKED
2103 #define FTRACE_ENTRY_PACKED(call, struct_name, id, tstruct, print) \
2104 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
2105 
2106 #include "trace_entries.h"
2107 
2108 #if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_FUNCTION_TRACER)
2109 int perf_ftrace_event_register(struct trace_event_call *call,
2110 			       enum trace_reg type, void *data);
2111 #else
2112 #define perf_ftrace_event_register NULL
2113 #endif
2114 
2115 #ifdef CONFIG_FTRACE_SYSCALLS
2116 void init_ftrace_syscalls(void);
2117 const char *get_syscall_name(int syscall);
2118 #else
2119 static inline void init_ftrace_syscalls(void) { }
2120 static inline const char *get_syscall_name(int syscall)
2121 {
2122 	return NULL;
2123 }
2124 #endif
2125 
2126 #ifdef CONFIG_EVENT_TRACING
2127 void trace_event_init(void);
2128 void trace_event_eval_update(struct trace_eval_map **map, int len);
2129 /* Used from boot time tracer */
2130 extern int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set);
2131 extern int trigger_process_regex(struct trace_event_file *file, char *buff);
2132 #else
2133 static inline void __init trace_event_init(void) { }
2134 static inline void trace_event_eval_update(struct trace_eval_map **map, int len) { }
2135 #endif
2136 
2137 #ifdef CONFIG_TRACER_SNAPSHOT
2138 void tracing_snapshot_instance(struct trace_array *tr);
2139 int tracing_alloc_snapshot_instance(struct trace_array *tr);
2140 int tracing_arm_snapshot(struct trace_array *tr);
2141 void tracing_disarm_snapshot(struct trace_array *tr);
2142 #else
2143 static inline void tracing_snapshot_instance(struct trace_array *tr) { }
2144 static inline int tracing_alloc_snapshot_instance(struct trace_array *tr)
2145 {
2146 	return 0;
2147 }
2148 static inline int tracing_arm_snapshot(struct trace_array *tr) { return 0; }
2149 static inline void tracing_disarm_snapshot(struct trace_array *tr) { }
2150 #endif
2151 
2152 #ifdef CONFIG_PREEMPT_TRACER
2153 void tracer_preempt_on(unsigned long a0, unsigned long a1);
2154 void tracer_preempt_off(unsigned long a0, unsigned long a1);
2155 #else
2156 static inline void tracer_preempt_on(unsigned long a0, unsigned long a1) { }
2157 static inline void tracer_preempt_off(unsigned long a0, unsigned long a1) { }
2158 #endif
2159 #ifdef CONFIG_IRQSOFF_TRACER
2160 void tracer_hardirqs_on(unsigned long a0, unsigned long a1);
2161 void tracer_hardirqs_off(unsigned long a0, unsigned long a1);
2162 #else
2163 static inline void tracer_hardirqs_on(unsigned long a0, unsigned long a1) { }
2164 static inline void tracer_hardirqs_off(unsigned long a0, unsigned long a1) { }
2165 #endif
2166 
2167 /*
2168  * Reset the state of the trace_iterator so that it can read consumed data.
2169  * Normally, the trace_iterator is used for reading the data when it is not
2170  * consumed, and must retain state.
2171  */
2172 static __always_inline void trace_iterator_reset(struct trace_iterator *iter)
2173 {
2174 	memset_startat(iter, 0, seq);
2175 	iter->pos = -1;
2176 }
2177 
2178 /* Check the name is good for event/group/fields */
2179 static inline bool __is_good_name(const char *name, bool hash_ok)
2180 {
2181 	if (!isalpha(*name) && *name != '_' && (!hash_ok || *name != '-'))
2182 		return false;
2183 	while (*++name != '\0') {
2184 		if (!isalpha(*name) && !isdigit(*name) && *name != '_' &&
2185 		    (!hash_ok || *name != '-'))
2186 			return false;
2187 	}
2188 	return true;
2189 }
2190 
2191 /* Check the name is good for event/group/fields */
2192 static inline bool is_good_name(const char *name)
2193 {
2194 	return __is_good_name(name, false);
2195 }
2196 
2197 /* Check the name is good for system */
2198 static inline bool is_good_system_name(const char *name)
2199 {
2200 	return __is_good_name(name, true);
2201 }
2202 
2203 /* Convert certain expected symbols into '_' when generating event names */
2204 static inline void sanitize_event_name(char *name)
2205 {
2206 	while (*name++ != '\0')
2207 		if (*name == ':' || *name == '.')
2208 			*name = '_';
2209 }
2210 
2211 /*
2212  * This is a generic way to read and write a u64 value from a file in tracefs.
2213  *
2214  * The value is stored on the variable pointed by *val. The value needs
2215  * to be at least *min and at most *max. The write is protected by an
2216  * existing *lock.
2217  */
2218 struct trace_min_max_param {
2219 	struct mutex	*lock;
2220 	u64		*val;
2221 	u64		*min;
2222 	u64		*max;
2223 };
2224 
2225 #define U64_STR_SIZE		24	/* 20 digits max */
2226 
2227 extern const struct file_operations trace_min_max_fops;
2228 
2229 #ifdef CONFIG_RV
2230 extern int rv_init_interface(void);
2231 #else
2232 static inline int rv_init_interface(void)
2233 {
2234 	return 0;
2235 }
2236 #endif
2237 
2238 /*
2239  * This is used only to distinguish
2240  * function address from trampoline code.
2241  * So this value has no meaning.
2242  */
2243 #define FTRACE_TRAMPOLINE_MARKER  ((unsigned long) INT_MAX)
2244 
2245 #endif /* _LINUX_KERNEL_TRACE_H */
2246