xref: /linux/kernel/trace/trace.h (revision 26f8453288d4c1fb8c96802eae15ddc988f5e068)
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 #include <linux/llist.h>
26 
27 #include "pid_list.h"
28 
29 #ifdef CONFIG_FTRACE_SYSCALLS
30 #include <asm/unistd.h>		/* For NR_syscalls	     */
31 #include <asm/syscall.h>	/* some archs define it here */
32 #endif
33 
34 #define TRACE_MODE_WRITE	0640
35 #define TRACE_MODE_READ		0440
36 
37 enum trace_type {
38 	__TRACE_FIRST_TYPE = 0,
39 
40 	TRACE_FN,
41 	TRACE_CTX,
42 	TRACE_WAKE,
43 	TRACE_STACK,
44 	TRACE_PRINT,
45 	TRACE_BPRINT,
46 	TRACE_MMIO_RW,
47 	TRACE_MMIO_MAP,
48 	TRACE_BRANCH,
49 	TRACE_GRAPH_RET,
50 	TRACE_GRAPH_ENT,
51 	TRACE_GRAPH_RETADDR_ENT,
52 	TRACE_USER_STACK,
53 	TRACE_BLK,
54 	TRACE_BPUTS,
55 	TRACE_HWLAT,
56 	TRACE_OSNOISE,
57 	TRACE_TIMERLAT,
58 	TRACE_RAW_DATA,
59 	TRACE_FUNC_REPEATS,
60 
61 	__TRACE_LAST_TYPE,
62 };
63 
64 
65 #undef __field
66 #define __field(type, item)		type	item;
67 
68 #undef __field_fn
69 #define __field_fn(type, item)		type	item;
70 
71 #undef __field_packed
72 #define __field_packed(type, item)	type	item;
73 
74 #undef __field_struct
75 #define __field_struct(type, item)	__field(type, item)
76 
77 #undef __field_desc
78 #define __field_desc(type, container, item)
79 
80 #undef __field_desc_packed
81 #define __field_desc_packed(type, container, item)
82 
83 #undef __array
84 #define __array(type, item, size)	type	item[size];
85 
86 /*
87  * For backward compatibility, older user space expects to see the
88  * kernel_stack event with a fixed size caller field. But today the fix
89  * size is ignored by the kernel, and the real structure is dynamic.
90  * Expose to user space: "unsigned long caller[8];" but the real structure
91  * will be "unsigned long caller[] __counted_by(size)"
92  */
93 #undef __stack_array
94 #define __stack_array(type, item, size, field)		type item[] __counted_by(field);
95 
96 #undef __array_desc
97 #define __array_desc(type, container, item, size)
98 
99 #undef __dynamic_array
100 #define __dynamic_array(type, item)	type	item[];
101 
102 #undef __rel_dynamic_array
103 #define __rel_dynamic_array(type, item)	type	item[];
104 
105 #undef F_STRUCT
106 #define F_STRUCT(args...)		args
107 
108 #undef FTRACE_ENTRY
109 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print)		\
110 	struct struct_name {						\
111 		struct trace_entry	ent;				\
112 		tstruct							\
113 	}
114 
115 #undef FTRACE_ENTRY_DUP
116 #define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk)
117 
118 #undef FTRACE_ENTRY_REG
119 #define FTRACE_ENTRY_REG(name, struct_name, id, tstruct, print,	regfn)	\
120 	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print))
121 
122 #undef FTRACE_ENTRY_PACKED
123 #define FTRACE_ENTRY_PACKED(name, struct_name, id, tstruct, print)	\
124 	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print)) __packed
125 
126 #include "trace_entries.h"
127 
128 /* Use this for memory failure errors */
129 #define MEM_FAIL(condition, fmt, ...)					\
130 	DO_ONCE_LITE_IF(condition, pr_err, "ERROR: " fmt, ##__VA_ARGS__)
131 
132 #define FAULT_STRING "(fault)"
133 
134 #define HIST_STACKTRACE_DEPTH	31
135 #define HIST_STACKTRACE_SIZE	(HIST_STACKTRACE_DEPTH * sizeof(unsigned long))
136 #define HIST_STACKTRACE_SKIP	5
137 
138 #define SYSCALL_FAULT_USER_MAX 165
139 
140 /*
141  * syscalls are special, and need special handling, this is why
142  * they are not included in trace_entries.h
143  */
144 struct syscall_trace_enter {
145 	struct trace_entry	ent;
146 	int			nr;
147 	unsigned long		args[];
148 };
149 
150 struct syscall_trace_exit {
151 	struct trace_entry	ent;
152 	int			nr;
153 	long			ret;
154 };
155 
156 struct kprobe_trace_entry_head {
157 	struct trace_entry	ent;
158 	unsigned long		ip;
159 };
160 
161 struct eprobe_trace_entry_head {
162 	struct trace_entry	ent;
163 };
164 
165 struct kretprobe_trace_entry_head {
166 	struct trace_entry	ent;
167 	unsigned long		func;
168 	unsigned long		ret_ip;
169 };
170 
171 struct fentry_trace_entry_head {
172 	struct trace_entry	ent;
173 	unsigned long		ip;
174 };
175 
176 struct fexit_trace_entry_head {
177 	struct trace_entry	ent;
178 	unsigned long		func;
179 	unsigned long		ret_ip;
180 };
181 
182 #define TRACE_BUF_SIZE		1024
183 
184 struct trace_array;
185 
186 /*
187  * The CPU trace array - it consists of thousands of trace entries
188  * plus some other descriptor data: (for example which task started
189  * the trace, etc.)
190  */
191 struct trace_array_cpu {
192 	local_t			disabled;
193 
194 	unsigned long		entries;
195 	unsigned long		saved_latency;
196 	unsigned long		critical_start;
197 	unsigned long		critical_end;
198 	unsigned long		critical_sequence;
199 	unsigned long		nice;
200 	unsigned long		policy;
201 	unsigned long		rt_priority;
202 	unsigned long		skipped_entries;
203 	u64			preempt_timestamp;
204 	pid_t			pid;
205 	kuid_t			uid;
206 	char			comm[TASK_COMM_LEN];
207 
208 #ifdef CONFIG_FUNCTION_TRACER
209 	int			ftrace_ignore_pid;
210 #endif
211 	bool			ignore_pid;
212 };
213 
214 struct tracer;
215 struct trace_option_dentry;
216 
217 struct array_buffer {
218 	struct trace_array		*tr;
219 	struct trace_buffer		*buffer;
220 	struct trace_array_cpu __percpu	*data;
221 	u64				time_start;
222 	int				cpu;
223 };
224 
225 #define TRACE_FLAGS_MAX_SIZE		64
226 
227 struct trace_options {
228 	struct tracer			*tracer;
229 	struct trace_option_dentry	*topts;
230 };
231 
232 struct trace_pid_list *trace_pid_list_alloc(void);
233 void trace_pid_list_free(struct trace_pid_list *pid_list);
234 bool trace_pid_list_is_set(struct trace_pid_list *pid_list, unsigned int pid);
235 int trace_pid_list_set(struct trace_pid_list *pid_list, unsigned int pid);
236 int trace_pid_list_clear(struct trace_pid_list *pid_list, unsigned int pid);
237 int trace_pid_list_first(struct trace_pid_list *pid_list, unsigned int *pid);
238 int trace_pid_list_next(struct trace_pid_list *pid_list, unsigned int pid,
239 			unsigned int *next);
240 
241 enum {
242 	TRACE_PIDS		= BIT(0),
243 	TRACE_NO_PIDS		= BIT(1),
244 };
245 
246 static inline bool pid_type_enabled(int type, struct trace_pid_list *pid_list,
247 				    struct trace_pid_list *no_pid_list)
248 {
249 	/* Return true if the pid list in type has pids */
250 	return ((type & TRACE_PIDS) && pid_list) ||
251 		((type & TRACE_NO_PIDS) && no_pid_list);
252 }
253 
254 static inline bool still_need_pid_events(int type, struct trace_pid_list *pid_list,
255 					 struct trace_pid_list *no_pid_list)
256 {
257 	/*
258 	 * Turning off what is in @type, return true if the "other"
259 	 * pid list, still has pids in it.
260 	 */
261 	return (!(type & TRACE_PIDS) && pid_list) ||
262 		(!(type & TRACE_NO_PIDS) && no_pid_list);
263 }
264 
265 typedef bool (*cond_update_fn_t)(struct trace_array *tr, void *cond_data);
266 
267 /**
268  * struct cond_snapshot - conditional snapshot data and callback
269  *
270  * The cond_snapshot structure encapsulates a callback function and
271  * data associated with the snapshot for a given tracing instance.
272  *
273  * When a snapshot is taken conditionally, by invoking
274  * tracing_snapshot_cond(tr, cond_data), the cond_data passed in is
275  * passed in turn to the cond_snapshot.update() function.  That data
276  * can be compared by the update() implementation with the cond_data
277  * contained within the struct cond_snapshot instance associated with
278  * the trace_array.  Because the tr->max_lock is held throughout the
279  * update() call, the update() function can directly retrieve the
280  * cond_snapshot and cond_data associated with the per-instance
281  * snapshot associated with the trace_array.
282  *
283  * The cond_snapshot.update() implementation can save data to be
284  * associated with the snapshot if it decides to, and returns 'true'
285  * in that case, or it returns 'false' if the conditional snapshot
286  * shouldn't be taken.
287  *
288  * The cond_snapshot instance is created and associated with the
289  * user-defined cond_data by tracing_cond_snapshot_enable().
290  * Likewise, the cond_snapshot instance is destroyed and is no longer
291  * associated with the trace instance by
292  * tracing_cond_snapshot_disable().
293  *
294  * The method below is required.
295  *
296  * @update: When a conditional snapshot is invoked, the update()
297  *	callback function is invoked with the tr->max_lock held.  The
298  *	update() implementation signals whether or not to actually
299  *	take the snapshot, by returning 'true' if so, 'false' if no
300  *	snapshot should be taken.  Because the max_lock is held for
301  *	the duration of update(), the implementation is safe to
302  *	directly retrieved and save any implementation data it needs
303  *	to in association with the snapshot.
304  */
305 struct cond_snapshot {
306 	void				*cond_data;
307 	cond_update_fn_t		update;
308 };
309 
310 /*
311  * struct trace_func_repeats - used to keep track of the consecutive
312  * (on the same CPU) calls of a single function.
313  */
314 struct trace_func_repeats {
315 	unsigned long	ip;
316 	unsigned long	parent_ip;
317 	unsigned long	count;
318 	u64		ts_last_call;
319 };
320 
321 struct trace_module_delta {
322 	struct rcu_head	rcu;
323 	long		delta[];
324 };
325 
326 /*
327  * The trace array - an array of per-CPU trace arrays. This is the
328  * highest level data structure that individual tracers deal with.
329  * They have on/off state as well:
330  */
331 struct trace_array {
332 	struct list_head	list;
333 	char			*name;
334 	struct array_buffer	array_buffer;
335 #ifdef CONFIG_TRACER_SNAPSHOT
336 	/*
337 	 * The snapshot_buffer is used to snapshot the trace when a maximum
338 	 * latency is reached, or when the user initiates a snapshot.
339 	 * Some tracers will use this to store a maximum trace while
340 	 * it continues examining live traces.
341 	 *
342 	 * The buffers for the snapshot_buffer are set up the same as the
343 	 * array_buffer. When a snapshot is taken, the buffer of the
344 	 * snapshot_buffer is swapped with the buffer of the array_buffer
345 	 * and the buffers are reset for the array_buffer so the tracing can
346 	 * continue.
347 	 */
348 	struct array_buffer	snapshot_buffer;
349 	bool			allocated_snapshot;
350 	spinlock_t		snapshot_trigger_lock;
351 	unsigned int		snapshot;
352 #ifdef CONFIG_TRACER_MAX_TRACE
353 	unsigned long		max_latency;
354 	struct dentry		*d_max_latency;
355 #ifdef CONFIG_FSNOTIFY
356 	struct work_struct	fsnotify_work;
357 	struct irq_work		fsnotify_irqwork;
358 #endif /* CONFIG_FSNOTIFY */
359 #endif /* CONFIG_TRACER_MAX_TRACE */
360 #endif /* CONFIG_TRACER_SNAPSHOT */
361 
362 	/* The below is for memory mapped ring buffer */
363 	unsigned int		mapped;
364 	unsigned long		range_addr_start;
365 	unsigned long		range_addr_size;
366 	char			*range_name;
367 	long			text_delta;
368 	struct trace_module_delta *module_delta;
369 	void			*scratch; /* pointer in persistent memory */
370 	int			scratch_size;
371 
372 	int			buffer_disabled;
373 
374 	struct trace_pid_list	__rcu *filtered_pids;
375 	struct trace_pid_list	__rcu *filtered_no_pids;
376 	/*
377 	 * max_lock is used to protect the swapping of buffers
378 	 * when taking a max snapshot. The buffers themselves are
379 	 * protected by per_cpu spinlocks. But the action of the swap
380 	 * needs its own lock.
381 	 *
382 	 * This is defined as a arch_spinlock_t in order to help
383 	 * with performance when lockdep debugging is enabled.
384 	 *
385 	 * It is also used in other places outside the update_max_tr
386 	 * so it needs to be defined outside of the
387 	 * CONFIG_TRACER_SNAPSHOT.
388 	 */
389 	arch_spinlock_t		max_lock;
390 #ifdef CONFIG_FTRACE_SYSCALLS
391 	int			sys_refcount_enter;
392 	int			sys_refcount_exit;
393 	struct trace_event_file	*enter_syscall_files[NR_syscalls];
394 	struct trace_event_file	*exit_syscall_files[NR_syscalls];
395 #endif
396 	int			stop_count;
397 	int			clock_id;
398 	int			nr_topts;
399 	bool			clear_trace;
400 	int			buffer_percent;
401 	unsigned int		n_err_log_entries;
402 	struct tracer		*current_trace;
403 	struct tracer_flags	*current_trace_flags;
404 	u64			trace_flags;
405 	unsigned char		trace_flags_index[TRACE_FLAGS_MAX_SIZE];
406 	unsigned int		flags;
407 	raw_spinlock_t		start_lock;
408 	const char		*system_names;
409 	struct list_head	err_log;
410 	struct dentry		*dir;
411 	struct dentry		*options;
412 	struct dentry		*percpu_dir;
413 	struct eventfs_inode	*event_dir;
414 	struct trace_options	*topts;
415 	struct list_head	systems;
416 	struct list_head	events;
417 	struct list_head	marker_list;
418 	struct list_head	tracers;
419 	struct trace_event_file *trace_marker_file;
420 	cpumask_var_t		tracing_cpumask; /* only trace on set CPUs */
421 	/* one per_cpu trace_pipe can be opened by only one user */
422 	cpumask_var_t		pipe_cpumask;
423 	int			ref;
424 	int			trace_ref;
425 #ifdef CONFIG_MODULES
426 	struct list_head	mod_events;
427 #endif
428 #ifdef CONFIG_FUNCTION_TRACER
429 	struct ftrace_ops	*ops;
430 	struct trace_pid_list	__rcu *function_pids;
431 	struct trace_pid_list	__rcu *function_no_pids;
432 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
433 	struct fgraph_ops	*gops;
434 #endif
435 #ifdef CONFIG_DYNAMIC_FTRACE
436 	/* All of these are protected by the ftrace_lock */
437 	struct list_head	func_probes;
438 	struct list_head	mod_trace;
439 	struct list_head	mod_notrace;
440 #endif
441 	/* function tracing enabled */
442 	int			function_enabled;
443 #endif
444 	int			no_filter_buffering_ref;
445 	unsigned int		syscall_buf_sz;
446 	struct list_head	hist_vars;
447 #ifdef CONFIG_TRACER_SNAPSHOT
448 	struct cond_snapshot	*cond_snapshot;
449 #endif
450 	struct trace_func_repeats	__percpu *last_func_repeats;
451 	/*
452 	 * On boot up, the ring buffer is set to the minimum size, so that
453 	 * we do not waste memory on systems that are not using tracing.
454 	 */
455 	bool ring_buffer_expanded;
456 };
457 
458 enum {
459 	TRACE_ARRAY_FL_GLOBAL		= BIT(0),
460 	TRACE_ARRAY_FL_BOOT		= BIT(1),
461 	TRACE_ARRAY_FL_LAST_BOOT	= BIT(2),
462 	TRACE_ARRAY_FL_MOD_INIT		= BIT(3),
463 	TRACE_ARRAY_FL_MEMMAP		= BIT(4),
464 	TRACE_ARRAY_FL_VMALLOC		= BIT(5),
465 };
466 
467 #ifdef CONFIG_MODULES
468 bool module_exists(const char *module);
469 #else
470 static inline bool module_exists(const char *module)
471 {
472 	return false;
473 }
474 #endif
475 
476 extern struct list_head ftrace_trace_arrays;
477 
478 extern struct mutex trace_types_lock;
479 
480 extern int trace_array_get(struct trace_array *tr);
481 extern int tracing_check_open_get_tr(struct trace_array *tr);
482 extern struct trace_array *trace_array_find(const char *instance);
483 extern struct trace_array *trace_array_find_get(const char *instance);
484 
485 extern u64 tracing_event_time_stamp(struct trace_buffer *buffer, struct ring_buffer_event *rbe);
486 extern int tracing_set_clock(struct trace_array *tr, const char *clockstr);
487 
488 extern bool trace_clock_in_ns(struct trace_array *tr);
489 
490 extern unsigned long trace_adjust_address(struct trace_array *tr, unsigned long addr);
491 
492 extern struct trace_array *printk_trace;
493 
494 /*
495  * The global tracer (top) should be the first trace array added,
496  * but we check the flag anyway.
497  */
498 static inline struct trace_array *top_trace_array(void)
499 {
500 	struct trace_array *tr;
501 
502 	if (list_empty(&ftrace_trace_arrays))
503 		return NULL;
504 
505 	tr = list_entry(ftrace_trace_arrays.prev,
506 			typeof(*tr), list);
507 	WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
508 	return tr;
509 }
510 
511 #define FTRACE_CMP_TYPE(var, type) \
512 	__builtin_types_compatible_p(typeof(var), type *)
513 
514 #undef IF_ASSIGN
515 #define IF_ASSIGN(var, entry, etype, id)			\
516 	if (FTRACE_CMP_TYPE(var, etype)) {			\
517 		var = (typeof(var))(entry);			\
518 		WARN_ON(id != 0 && (entry)->type != id);	\
519 		break;						\
520 	}
521 
522 /* Will cause compile errors if type is not found. */
523 extern void __ftrace_bad_type(void);
524 
525 /*
526  * The trace_assign_type is a verifier that the entry type is
527  * the same as the type being assigned. To add new types simply
528  * add a line with the following format:
529  *
530  * IF_ASSIGN(var, ent, type, id);
531  *
532  *  Where "type" is the trace type that includes the trace_entry
533  *  as the "ent" item. And "id" is the trace identifier that is
534  *  used in the trace_type enum.
535  *
536  *  If the type can have more than one id, then use zero.
537  */
538 #define trace_assign_type(var, ent)					\
539 	do {								\
540 		IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);	\
541 		IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);	\
542 		IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);	\
543 		IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
544 		IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);	\
545 		IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT);	\
546 		IF_ASSIGN(var, ent, struct bputs_entry, TRACE_BPUTS);	\
547 		IF_ASSIGN(var, ent, struct hwlat_entry, TRACE_HWLAT);	\
548 		IF_ASSIGN(var, ent, struct osnoise_entry, TRACE_OSNOISE);\
549 		IF_ASSIGN(var, ent, struct timerlat_entry, TRACE_TIMERLAT);\
550 		IF_ASSIGN(var, ent, struct raw_data_entry, TRACE_RAW_DATA);\
551 		IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,		\
552 			  TRACE_MMIO_RW);				\
553 		IF_ASSIGN(var, ent, struct trace_mmiotrace_map,		\
554 			  TRACE_MMIO_MAP);				\
555 		IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
556 		IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,	\
557 			  TRACE_GRAPH_ENT);		\
558 		IF_ASSIGN(var, ent, struct fgraph_retaddr_ent_entry,\
559 			  TRACE_GRAPH_RETADDR_ENT);		\
560 		IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,	\
561 			  TRACE_GRAPH_RET);		\
562 		IF_ASSIGN(var, ent, struct func_repeats_entry,		\
563 			  TRACE_FUNC_REPEATS);				\
564 		__ftrace_bad_type();					\
565 	} while (0)
566 
567 /*
568  * An option specific to a tracer. This is a boolean value.
569  * The bit is the bit index that sets its value on the
570  * flags value in struct tracer_flags.
571  */
572 struct tracer_opt {
573 	const char	*name; /* Will appear on the trace_options file */
574 	u32		bit; /* Mask assigned in val field in tracer_flags */
575 };
576 
577 /*
578  * The set of specific options for a tracer. Your tracer
579  * have to set the initial value of the flags val.
580  */
581 struct tracer_flags {
582 	u32			val;
583 	struct tracer_opt	*opts;
584 	struct tracer		*trace;
585 };
586 
587 /* Makes more easy to define a tracer opt */
588 #define TRACER_OPT(s, b)	.name = #s, .bit = b
589 
590 
591 struct trace_option_dentry {
592 	struct tracer_opt		*opt;
593 	struct tracer_flags		*flags;
594 	struct trace_array		*tr;
595 	struct dentry			*entry;
596 };
597 
598 /**
599  * struct tracer - a specific tracer and its callbacks to interact with tracefs
600  * @name: the name chosen to select it on the available_tracers file
601  * @init: called when one switches to this tracer (echo name > current_tracer)
602  * @reset: called when one switches to another tracer
603  * @start: called when tracing is unpaused (echo 1 > tracing_on)
604  * @stop: called when tracing is paused (echo 0 > tracing_on)
605  * @update_thresh: called when tracing_thresh is updated
606  * @open: called when the trace file is opened
607  * @pipe_open: called when the trace_pipe file is opened
608  * @close: called when the trace file is released
609  * @pipe_close: called when the trace_pipe file is released
610  * @read: override the default read callback on trace_pipe
611  * @splice_read: override the default splice_read callback on trace_pipe
612  * @selftest: selftest to run on boot (see trace_selftest.c)
613  * @print_headers: override the first lines that describe your columns
614  * @print_line: callback that prints a trace
615  * @set_flag: signals one of your private flags changed (trace_options file)
616  * @flags: your private flags
617  */
618 struct tracer {
619 	const char		*name;
620 	int			(*init)(struct trace_array *tr);
621 	void			(*reset)(struct trace_array *tr);
622 	void			(*start)(struct trace_array *tr);
623 	void			(*stop)(struct trace_array *tr);
624 	int			(*update_thresh)(struct trace_array *tr);
625 	void			(*open)(struct trace_iterator *iter);
626 	void			(*pipe_open)(struct trace_iterator *iter);
627 	void			(*close)(struct trace_iterator *iter);
628 	void			(*pipe_close)(struct trace_iterator *iter);
629 	ssize_t			(*read)(struct trace_iterator *iter,
630 					struct file *filp, char __user *ubuf,
631 					size_t cnt, loff_t *ppos);
632 	ssize_t			(*splice_read)(struct trace_iterator *iter,
633 					       struct file *filp,
634 					       loff_t *ppos,
635 					       struct pipe_inode_info *pipe,
636 					       size_t len,
637 					       unsigned int flags);
638 #ifdef CONFIG_FTRACE_STARTUP_TEST
639 	int			(*selftest)(struct tracer *trace,
640 					    struct trace_array *tr);
641 #endif
642 	void			(*print_header)(struct seq_file *m);
643 	enum print_line_t	(*print_line)(struct trace_iterator *iter);
644 	/* If you handled the flag setting, return 0 */
645 	int			(*set_flag)(struct trace_array *tr,
646 					    u32 old_flags, u32 bit, int set);
647 	/* Return 0 if OK with change, else return non-zero */
648 	int			(*flag_changed)(struct trace_array *tr,
649 						u64 mask, int set);
650 	struct tracer		*next;
651 	struct tracer_flags	*flags;
652 	struct tracer_flags	*default_flags;
653 	int			enabled;
654 	bool			print_max;
655 	bool			allow_instances;
656 #ifdef CONFIG_TRACER_MAX_TRACE
657 	bool			use_max_tr;
658 #endif
659 	/* True if tracer cannot be enabled in kernel param */
660 	bool			noboot;
661 };
662 
663 static inline struct ring_buffer_iter *
664 trace_buffer_iter(struct trace_iterator *iter, int cpu)
665 {
666 	return iter->buffer_iter ? iter->buffer_iter[cpu] : NULL;
667 }
668 
669 extern int tracing_disabled;
670 
671 int tracer_init(struct tracer *t, struct trace_array *tr);
672 int tracing_is_enabled(void);
673 void tracing_reset_online_cpus(struct array_buffer *buf);
674 void tracing_reset_all_online_cpus(void);
675 void tracing_reset_all_online_cpus_unlocked(void);
676 int tracing_open_generic(struct inode *inode, struct file *filp);
677 int tracing_open_generic_tr(struct inode *inode, struct file *filp);
678 int tracing_release_generic_tr(struct inode *inode, struct file *file);
679 int tracing_open_file_tr(struct inode *inode, struct file *filp);
680 int tracing_release_file_tr(struct inode *inode, struct file *filp);
681 int tracing_single_release_file_tr(struct inode *inode, struct file *filp);
682 bool tracer_tracing_is_on(struct trace_array *tr);
683 void tracer_tracing_on(struct trace_array *tr);
684 void tracer_tracing_off(struct trace_array *tr);
685 void tracer_tracing_disable(struct trace_array *tr);
686 void tracer_tracing_enable(struct trace_array *tr);
687 struct dentry *trace_create_file(const char *name,
688 				 umode_t mode,
689 				 struct dentry *parent,
690 				 void *data,
691 				 const struct file_operations *fops);
692 struct dentry *trace_create_cpu_file(const char *name,
693 				     umode_t mode,
694 				     struct dentry *parent,
695 				     void *data,
696 				     long cpu,
697 				     const struct file_operations *fops);
698 int tracing_get_cpu(struct inode *inode);
699 
700 
701 /**
702  * tracer_tracing_is_on_cpu - show real state of ring buffer enabled on for a cpu
703  * @tr : the trace array to know if ring buffer is enabled
704  * @cpu: The cpu buffer to check if enabled
705  *
706  * Shows real state of the per CPU buffer if it is enabled or not.
707  */
708 static inline bool tracer_tracing_is_on_cpu(struct trace_array *tr, int cpu)
709 {
710 	if (tr->array_buffer.buffer)
711 		return ring_buffer_record_is_on_cpu(tr->array_buffer.buffer, cpu);
712 	return false;
713 }
714 
715 int tracing_init_dentry(void);
716 
717 struct ring_buffer_event;
718 
719 struct ring_buffer_event *
720 trace_buffer_lock_reserve(struct trace_buffer *buffer,
721 			  int type,
722 			  unsigned long len,
723 			  unsigned int trace_ctx);
724 
725 int ring_buffer_meta_seq_init(struct file *file, struct trace_buffer *buffer, int cpu);
726 
727 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
728 						struct trace_array_cpu *data);
729 
730 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
731 					  int *ent_cpu, u64 *ent_ts);
732 
733 void trace_buffer_unlock_commit_nostack(struct trace_buffer *buffer,
734 					struct ring_buffer_event *event);
735 
736 bool trace_is_tracepoint_string(const char *str);
737 const char *trace_event_format(struct trace_iterator *iter, const char *fmt);
738 char *trace_iter_expand_format(struct trace_iterator *iter);
739 bool ignore_event(struct trace_iterator *iter);
740 
741 int trace_empty(struct trace_iterator *iter);
742 
743 void *trace_find_next_entry_inc(struct trace_iterator *iter);
744 
745 void trace_init_global_iter(struct trace_iterator *iter);
746 
747 void tracing_iter_reset(struct trace_iterator *iter, int cpu);
748 
749 unsigned long trace_total_entries_cpu(struct trace_array *tr, int cpu);
750 unsigned long trace_total_entries(struct trace_array *tr);
751 
752 void trace_function(struct trace_array *tr,
753 		    unsigned long ip,
754 		    unsigned long parent_ip,
755 		    unsigned int trace_ctx,
756 		    struct ftrace_regs *regs);
757 void trace_graph_function(struct trace_array *tr,
758 		    unsigned long ip,
759 		    unsigned long parent_ip,
760 		    unsigned int trace_ctx);
761 void trace_latency_header(struct seq_file *m);
762 void trace_default_header(struct seq_file *m);
763 void print_trace_header(struct seq_file *m, struct trace_iterator *iter);
764 
765 void trace_graph_return(struct ftrace_graph_ret *trace, struct fgraph_ops *gops,
766 			struct ftrace_regs *fregs);
767 int trace_graph_entry(struct ftrace_graph_ent *trace, struct fgraph_ops *gops,
768 		      struct ftrace_regs *fregs);
769 
770 void tracing_start_cmdline_record(void);
771 void tracing_stop_cmdline_record(void);
772 void tracing_start_tgid_record(void);
773 void tracing_stop_tgid_record(void);
774 
775 int register_tracer(struct tracer *type);
776 int is_tracing_stopped(void);
777 
778 loff_t tracing_lseek(struct file *file, loff_t offset, int whence);
779 
780 extern cpumask_var_t __read_mostly tracing_buffer_mask;
781 
782 #define for_each_tracing_cpu(cpu)	\
783 	for_each_cpu(cpu, tracing_buffer_mask)
784 
785 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
786 
787 extern unsigned long tracing_thresh;
788 extern struct workqueue_struct *trace_init_wq __initdata;
789 
790 /* PID filtering */
791 
792 bool trace_find_filtered_pid(struct trace_pid_list *filtered_pids,
793 			     pid_t search_pid);
794 bool trace_ignore_this_task(struct trace_pid_list *filtered_pids,
795 			    struct trace_pid_list *filtered_no_pids,
796 			    struct task_struct *task);
797 void trace_filter_add_remove_task(struct trace_pid_list *pid_list,
798 				  struct task_struct *self,
799 				  struct task_struct *task);
800 void *trace_pid_next(struct trace_pid_list *pid_list, void *v, loff_t *pos);
801 void *trace_pid_start(struct trace_pid_list *pid_list, loff_t *pos);
802 int trace_pid_show(struct seq_file *m, void *v);
803 int trace_pid_write(struct trace_pid_list *filtered_pids,
804 		    struct trace_pid_list **new_pid_list,
805 		    const char __user *ubuf, size_t cnt);
806 
807 #ifdef CONFIG_TRACER_SNAPSHOT
808 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu,
809 		   void *cond_data);
810 void update_max_tr_single(struct trace_array *tr,
811 			  struct task_struct *tsk, int cpu);
812 
813 #if defined(CONFIG_TRACER_MAX_TRACE) && defined(CONFIG_FSNOTIFY)
814 # define LATENCY_FS_NOTIFY
815 #endif
816 
817 #ifdef LATENCY_FS_NOTIFY
818 void latency_fsnotify(struct trace_array *tr);
819 #else
820 static inline void latency_fsnotify(struct trace_array *tr) { }
821 #endif
822 #endif /* CONFIG_TRACER_SNAPSHOT */
823 
824 #ifdef CONFIG_STACKTRACE
825 void __trace_stack(struct trace_array *tr, unsigned int trace_ctx, int skip);
826 #else
827 static inline void __trace_stack(struct trace_array *tr, unsigned int trace_ctx,
828 				 int skip)
829 {
830 }
831 #endif /* CONFIG_STACKTRACE */
832 
833 #ifdef CONFIG_TRACER_MAX_TRACE
834 static inline bool tracer_uses_snapshot(struct tracer *tracer)
835 {
836 	return tracer->use_max_tr;
837 }
838 #else
839 static inline bool tracer_uses_snapshot(struct tracer *tracer)
840 {
841 	return false;
842 }
843 #endif
844 
845 void trace_last_func_repeats(struct trace_array *tr,
846 			     struct trace_func_repeats *last_info,
847 			     unsigned int trace_ctx);
848 
849 extern u64 ftrace_now(int cpu);
850 
851 extern void trace_find_cmdline(int pid, char comm[]);
852 extern int trace_find_tgid(int pid);
853 extern void trace_event_follow_fork(struct trace_array *tr, bool enable);
854 
855 extern int trace_events_enabled(struct trace_array *tr, const char *system);
856 
857 #ifdef CONFIG_DYNAMIC_FTRACE
858 extern unsigned long ftrace_update_tot_cnt;
859 extern unsigned long ftrace_number_of_pages;
860 extern unsigned long ftrace_number_of_groups;
861 extern u64 ftrace_update_time;
862 extern u64 ftrace_total_mod_time;
863 void ftrace_init_trace_array(struct trace_array *tr);
864 #else
865 static inline void ftrace_init_trace_array(struct trace_array *tr) { }
866 #endif
867 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
868 extern int DYN_FTRACE_TEST_NAME(void);
869 #define DYN_FTRACE_TEST_NAME2 trace_selftest_dynamic_test_func2
870 extern int DYN_FTRACE_TEST_NAME2(void);
871 
872 extern void trace_set_ring_buffer_expanded(struct trace_array *tr);
873 extern bool tracing_selftest_disabled;
874 
875 #ifdef CONFIG_FTRACE_STARTUP_TEST
876 extern void __init disable_tracing_selftest(const char *reason);
877 
878 extern int trace_selftest_startup_function(struct tracer *trace,
879 					   struct trace_array *tr);
880 extern int trace_selftest_startup_function_graph(struct tracer *trace,
881 						 struct trace_array *tr);
882 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
883 					  struct trace_array *tr);
884 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
885 					     struct trace_array *tr);
886 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
887 						 struct trace_array *tr);
888 extern int trace_selftest_startup_wakeup(struct tracer *trace,
889 					 struct trace_array *tr);
890 extern int trace_selftest_startup_nop(struct tracer *trace,
891 					 struct trace_array *tr);
892 extern int trace_selftest_startup_branch(struct tracer *trace,
893 					 struct trace_array *tr);
894 extern bool __read_mostly tracing_selftest_running;
895 /*
896  * Tracer data references selftest functions that only occur
897  * on boot up. These can be __init functions. Thus, when selftests
898  * are enabled, then the tracers need to reference __init functions.
899  */
900 #define __tracer_data		__refdata
901 #else
902 static inline void __init disable_tracing_selftest(const char *reason)
903 {
904 }
905 /* Tracers are seldom changed. Optimize when selftests are disabled. */
906 #define __tracer_data		__read_mostly
907 #define tracing_selftest_running	0
908 #endif /* CONFIG_FTRACE_STARTUP_TEST */
909 
910 extern void *head_page(struct trace_array_cpu *data);
911 extern unsigned long long ns2usecs(u64 nsec);
912 
913 __printf(2, 0)
914 int trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
915 __printf(2, 0)
916 int trace_vprintk(unsigned long ip, const char *fmt, va_list args);
917 __printf(3, 0)
918 int trace_array_vprintk(struct trace_array *tr,
919 			unsigned long ip, const char *fmt, va_list args);
920 __printf(3, 4)
921 int trace_array_printk_buf(struct trace_buffer *buffer,
922 			   unsigned long ip, const char *fmt, ...);
923 void trace_printk_seq(struct trace_seq *s);
924 enum print_line_t print_trace_line(struct trace_iterator *iter);
925 
926 extern char trace_find_mark(unsigned long long duration);
927 
928 struct ftrace_hash;
929 
930 struct ftrace_mod_load {
931 	struct list_head	list;
932 	char			*func;
933 	char			*module;
934 	int			 enable;
935 };
936 
937 enum {
938 	FTRACE_HASH_FL_MOD	= (1 << 0),
939 };
940 
941 struct ftrace_hash {
942 	unsigned long		size_bits;
943 	struct hlist_head	*buckets;
944 	unsigned long		count;
945 	unsigned long		flags;
946 	struct rcu_head		rcu;
947 };
948 
949 struct ftrace_func_entry *
950 ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip);
951 
952 static __always_inline bool ftrace_hash_empty(struct ftrace_hash *hash)
953 {
954 	return !hash || !(hash->count || (hash->flags & FTRACE_HASH_FL_MOD));
955 }
956 
957 /* Standard output formatting function used for function return traces */
958 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
959 
960 /* Flag options */
961 #define TRACE_GRAPH_PRINT_OVERRUN       0x1
962 #define TRACE_GRAPH_PRINT_CPU           0x2
963 #define TRACE_GRAPH_PRINT_OVERHEAD      0x4
964 #define TRACE_GRAPH_PRINT_PROC          0x8
965 #define TRACE_GRAPH_PRINT_DURATION      0x10
966 #define TRACE_GRAPH_PRINT_ABS_TIME      0x20
967 #define TRACE_GRAPH_PRINT_REL_TIME      0x40
968 #define TRACE_GRAPH_PRINT_IRQS          0x80
969 #define TRACE_GRAPH_PRINT_TAIL          0x100
970 #define TRACE_GRAPH_SLEEP_TIME          0x200
971 #define TRACE_GRAPH_GRAPH_TIME          0x400
972 #define TRACE_GRAPH_PRINT_RETVAL        0x800
973 #define TRACE_GRAPH_PRINT_RETVAL_HEX    0x1000
974 #define TRACE_GRAPH_PRINT_RETADDR       0x2000
975 #define TRACE_GRAPH_ARGS		0x4000
976 #define TRACE_GRAPH_PRINT_FILL_SHIFT	28
977 #define TRACE_GRAPH_PRINT_FILL_MASK	(0x3 << TRACE_GRAPH_PRINT_FILL_SHIFT)
978 
979 #ifdef CONFIG_FUNCTION_PROFILER
980 extern void ftrace_graph_graph_time_control(bool enable);
981 #else
982 static inline void ftrace_graph_graph_time_control(bool enable) { }
983 #endif
984 
985 extern enum print_line_t
986 print_graph_function_flags(struct trace_iterator *iter, u32 flags);
987 extern void print_graph_headers_flags(struct seq_file *s, u32 flags);
988 extern void
989 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
990 extern void graph_trace_open(struct trace_iterator *iter);
991 extern void graph_trace_close(struct trace_iterator *iter);
992 extern int __trace_graph_entry(struct trace_array *tr,
993 			       struct ftrace_graph_ent *trace,
994 			       unsigned int trace_ctx);
995 extern int __trace_graph_retaddr_entry(struct trace_array *tr,
996 				struct ftrace_graph_ent *trace,
997 				unsigned int trace_ctx,
998 				unsigned long retaddr,
999 				struct ftrace_regs *fregs);
1000 extern void __trace_graph_return(struct trace_array *tr,
1001 				 struct ftrace_graph_ret *trace,
1002 				 unsigned int trace_ctx,
1003 				 u64 calltime, u64 rettime);
1004 
1005 extern void init_array_fgraph_ops(struct trace_array *tr, struct ftrace_ops *ops);
1006 extern int allocate_fgraph_ops(struct trace_array *tr, struct ftrace_ops *ops);
1007 extern void free_fgraph_ops(struct trace_array *tr);
1008 
1009 enum {
1010 	TRACE_GRAPH_FL		= 1,
1011 
1012 	/*
1013 	 * In the very unlikely case that an interrupt came in
1014 	 * at a start of graph tracing, and we want to trace
1015 	 * the function in that interrupt, the depth can be greater
1016 	 * than zero, because of the preempted start of a previous
1017 	 * trace. In an even more unlikely case, depth could be 2
1018 	 * if a softirq interrupted the start of graph tracing,
1019 	 * followed by an interrupt preempting a start of graph
1020 	 * tracing in the softirq, and depth can even be 3
1021 	 * if an NMI came in at the start of an interrupt function
1022 	 * that preempted a softirq start of a function that
1023 	 * preempted normal context!!!! Luckily, it can't be
1024 	 * greater than 3, so the next two bits are a mask
1025 	 * of what the depth is when we set TRACE_GRAPH_FL
1026 	 */
1027 
1028 	TRACE_GRAPH_DEPTH_START_BIT,
1029 	TRACE_GRAPH_DEPTH_END_BIT,
1030 
1031 	/*
1032 	 * To implement set_graph_notrace, if this bit is set, we ignore
1033 	 * function graph tracing of called functions, until the return
1034 	 * function is called to clear it.
1035 	 */
1036 	TRACE_GRAPH_NOTRACE_BIT,
1037 };
1038 
1039 #define TRACE_GRAPH_NOTRACE		(1 << TRACE_GRAPH_NOTRACE_BIT)
1040 
1041 static inline unsigned long ftrace_graph_depth(unsigned long *task_var)
1042 {
1043 	return (*task_var >> TRACE_GRAPH_DEPTH_START_BIT) & 3;
1044 }
1045 
1046 static inline void ftrace_graph_set_depth(unsigned long *task_var, int depth)
1047 {
1048 	*task_var &= ~(3 << TRACE_GRAPH_DEPTH_START_BIT);
1049 	*task_var |= (depth & 3) << TRACE_GRAPH_DEPTH_START_BIT;
1050 }
1051 
1052 #ifdef CONFIG_DYNAMIC_FTRACE
1053 extern struct ftrace_hash __rcu *ftrace_graph_hash;
1054 extern struct ftrace_hash __rcu *ftrace_graph_notrace_hash;
1055 
1056 static inline int
1057 ftrace_graph_addr(unsigned long *task_var, struct ftrace_graph_ent *trace)
1058 {
1059 	unsigned long addr = trace->func;
1060 	int ret = 0;
1061 	struct ftrace_hash *hash;
1062 
1063 	preempt_disable_notrace();
1064 
1065 	/*
1066 	 * Have to open code "rcu_dereference_sched()" because the
1067 	 * function graph tracer can be called when RCU is not
1068 	 * "watching".
1069 	 * Protected with schedule_on_each_cpu(ftrace_sync)
1070 	 */
1071 	hash = rcu_dereference_protected(ftrace_graph_hash, !preemptible());
1072 
1073 	if (ftrace_hash_empty(hash)) {
1074 		ret = 1;
1075 		goto out;
1076 	}
1077 
1078 	if (ftrace_lookup_ip(hash, addr)) {
1079 		/*
1080 		 * This needs to be cleared on the return functions
1081 		 * when the depth is zero.
1082 		 */
1083 		*task_var |= TRACE_GRAPH_FL;
1084 		ftrace_graph_set_depth(task_var, trace->depth);
1085 
1086 		/*
1087 		 * If no irqs are to be traced, but a set_graph_function
1088 		 * is set, and called by an interrupt handler, we still
1089 		 * want to trace it.
1090 		 */
1091 		if (in_hardirq())
1092 			trace_recursion_set(TRACE_IRQ_BIT);
1093 		else
1094 			trace_recursion_clear(TRACE_IRQ_BIT);
1095 		ret = 1;
1096 	}
1097 
1098 out:
1099 	preempt_enable_notrace();
1100 	return ret;
1101 }
1102 
1103 static inline void
1104 ftrace_graph_addr_finish(struct fgraph_ops *gops, struct ftrace_graph_ret *trace)
1105 {
1106 	unsigned long *task_var = fgraph_get_task_var(gops);
1107 
1108 	if ((*task_var & TRACE_GRAPH_FL) &&
1109 	    trace->depth == ftrace_graph_depth(task_var))
1110 		*task_var &= ~TRACE_GRAPH_FL;
1111 }
1112 
1113 static inline int ftrace_graph_notrace_addr(unsigned long addr)
1114 {
1115 	int ret = 0;
1116 	struct ftrace_hash *notrace_hash;
1117 
1118 	preempt_disable_notrace();
1119 
1120 	/*
1121 	 * Have to open code "rcu_dereference_sched()" because the
1122 	 * function graph tracer can be called when RCU is not
1123 	 * "watching".
1124 	 * Protected with schedule_on_each_cpu(ftrace_sync)
1125 	 */
1126 	notrace_hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
1127 						 !preemptible());
1128 
1129 	if (ftrace_lookup_ip(notrace_hash, addr))
1130 		ret = 1;
1131 
1132 	preempt_enable_notrace();
1133 	return ret;
1134 }
1135 #else
1136 static inline int ftrace_graph_addr(unsigned long *task_var, struct ftrace_graph_ent *trace)
1137 {
1138 	return 1;
1139 }
1140 
1141 static inline int ftrace_graph_notrace_addr(unsigned long addr)
1142 {
1143 	return 0;
1144 }
1145 static inline void ftrace_graph_addr_finish(struct fgraph_ops *gops, struct ftrace_graph_ret *trace)
1146 { }
1147 #endif /* CONFIG_DYNAMIC_FTRACE */
1148 
1149 extern unsigned int fgraph_max_depth;
1150 extern int fgraph_no_sleep_time;
1151 extern bool fprofile_no_sleep_time;
1152 
1153 static inline bool
1154 ftrace_graph_ignore_func(struct fgraph_ops *gops, struct ftrace_graph_ent *trace)
1155 {
1156 	unsigned long *task_var = fgraph_get_task_var(gops);
1157 
1158 	/* trace it when it is-nested-in or is a function enabled. */
1159 	return !((*task_var & TRACE_GRAPH_FL) ||
1160 		 ftrace_graph_addr(task_var, trace)) ||
1161 		(trace->depth < 0) ||
1162 		(fgraph_max_depth && trace->depth >= fgraph_max_depth);
1163 }
1164 
1165 void fgraph_init_ops(struct ftrace_ops *dst_ops,
1166 		     struct ftrace_ops *src_ops);
1167 
1168 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
1169 static inline enum print_line_t
1170 print_graph_function_flags(struct trace_iterator *iter, u32 flags)
1171 {
1172 	return TRACE_TYPE_UNHANDLED;
1173 }
1174 static inline void free_fgraph_ops(struct trace_array *tr) { }
1175 /* ftrace_ops may not be defined */
1176 #define init_array_fgraph_ops(tr, ops) do { } while (0)
1177 #define allocate_fgraph_ops(tr, ops) ({ 0; })
1178 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
1179 
1180 extern struct list_head ftrace_pids;
1181 
1182 #ifdef CONFIG_FUNCTION_TRACER
1183 
1184 #define FTRACE_PID_IGNORE	-1
1185 #define FTRACE_PID_TRACE	-2
1186 
1187 struct ftrace_func_command {
1188 	struct list_head	list;
1189 	char			*name;
1190 	int			(*func)(struct trace_array *tr,
1191 					struct ftrace_hash *hash,
1192 					char *func, char *cmd,
1193 					char *params, int enable);
1194 };
1195 extern bool ftrace_filter_param __initdata;
1196 extern int ftrace_is_dead(void);
1197 int ftrace_create_function_files(struct trace_array *tr,
1198 				 struct dentry *parent);
1199 void ftrace_destroy_function_files(struct trace_array *tr);
1200 int ftrace_allocate_ftrace_ops(struct trace_array *tr);
1201 void ftrace_free_ftrace_ops(struct trace_array *tr);
1202 void ftrace_init_global_array_ops(struct trace_array *tr);
1203 struct trace_array *trace_get_global_array(void);
1204 void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func);
1205 void ftrace_reset_array_ops(struct trace_array *tr);
1206 void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer);
1207 void ftrace_init_tracefs_toplevel(struct trace_array *tr,
1208 				  struct dentry *d_tracer);
1209 void ftrace_clear_pids(struct trace_array *tr);
1210 int init_function_trace(void);
1211 void ftrace_pid_follow_fork(struct trace_array *tr, bool enable);
1212 #else
1213 static inline int ftrace_is_dead(void) { return 0; }
1214 static inline int
1215 ftrace_create_function_files(struct trace_array *tr,
1216 			     struct dentry *parent)
1217 {
1218 	return 0;
1219 }
1220 static inline int ftrace_allocate_ftrace_ops(struct trace_array *tr)
1221 {
1222 	return 0;
1223 }
1224 static inline void ftrace_free_ftrace_ops(struct trace_array *tr) { }
1225 static inline void ftrace_destroy_function_files(struct trace_array *tr) { }
1226 static inline __init void
1227 ftrace_init_global_array_ops(struct trace_array *tr) { }
1228 static inline void ftrace_reset_array_ops(struct trace_array *tr) { }
1229 static inline void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d) { }
1230 static inline void ftrace_init_tracefs_toplevel(struct trace_array *tr, struct dentry *d) { }
1231 static inline void ftrace_clear_pids(struct trace_array *tr) { }
1232 static inline int init_function_trace(void) { return 0; }
1233 static inline void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) { }
1234 /* ftace_func_t type is not defined, use macro instead of static inline */
1235 #define ftrace_init_array_ops(tr, func) do { } while (0)
1236 #endif /* CONFIG_FUNCTION_TRACER */
1237 
1238 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
1239 
1240 struct ftrace_probe_ops {
1241 	void			(*func)(unsigned long ip,
1242 					unsigned long parent_ip,
1243 					struct trace_array *tr,
1244 					struct ftrace_probe_ops *ops,
1245 					void *data);
1246 	int			(*init)(struct ftrace_probe_ops *ops,
1247 					struct trace_array *tr,
1248 					unsigned long ip, void *init_data,
1249 					void **data);
1250 	void			(*free)(struct ftrace_probe_ops *ops,
1251 					struct trace_array *tr,
1252 					unsigned long ip, void *data);
1253 	int			(*print)(struct seq_file *m,
1254 					 unsigned long ip,
1255 					 struct ftrace_probe_ops *ops,
1256 					 void *data);
1257 };
1258 
1259 struct ftrace_func_mapper;
1260 typedef int (*ftrace_mapper_func)(void *data);
1261 
1262 struct ftrace_func_mapper *allocate_ftrace_func_mapper(void);
1263 void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
1264 					   unsigned long ip);
1265 int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
1266 			       unsigned long ip, void *data);
1267 void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
1268 				   unsigned long ip);
1269 void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
1270 			     ftrace_mapper_func free_func);
1271 
1272 extern int
1273 register_ftrace_function_probe(char *glob, struct trace_array *tr,
1274 			       struct ftrace_probe_ops *ops, void *data);
1275 extern int
1276 unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
1277 				      struct ftrace_probe_ops *ops);
1278 extern void clear_ftrace_function_probes(struct trace_array *tr);
1279 
1280 int register_ftrace_command(struct ftrace_func_command *cmd);
1281 int unregister_ftrace_command(struct ftrace_func_command *cmd);
1282 
1283 void ftrace_create_filter_files(struct ftrace_ops *ops,
1284 				struct dentry *parent);
1285 void ftrace_destroy_filter_files(struct ftrace_ops *ops);
1286 
1287 extern int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
1288 			     int len, int reset);
1289 extern int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
1290 			      int len, int reset);
1291 #else
1292 struct ftrace_func_command;
1293 
1294 static inline __init int register_ftrace_command(struct ftrace_func_command *cmd)
1295 {
1296 	return -EINVAL;
1297 }
1298 static inline __init int unregister_ftrace_command(char *cmd_name)
1299 {
1300 	return -EINVAL;
1301 }
1302 static inline void clear_ftrace_function_probes(struct trace_array *tr)
1303 {
1304 }
1305 
1306 /*
1307  * The ops parameter passed in is usually undefined.
1308  * This must be a macro.
1309  */
1310 #define ftrace_create_filter_files(ops, parent) do { } while (0)
1311 #define ftrace_destroy_filter_files(ops) do { } while (0)
1312 #endif /* CONFIG_FUNCTION_TRACER && CONFIG_DYNAMIC_FTRACE */
1313 
1314 bool ftrace_event_is_function(struct trace_event_call *call);
1315 
1316 /*
1317  * struct trace_parser - servers for reading the user input separated by spaces
1318  * @cont: set if the input is not complete - no final space char was found
1319  * @buffer: holds the parsed user input
1320  * @idx: user input length
1321  * @size: buffer size
1322  */
1323 struct trace_parser {
1324 	bool		cont;
1325 	bool		fail;
1326 	char		*buffer;
1327 	unsigned	idx;
1328 	unsigned	size;
1329 };
1330 
1331 static inline bool trace_parser_loaded(struct trace_parser *parser)
1332 {
1333 	return !parser->fail && parser->idx != 0;
1334 }
1335 
1336 static inline bool trace_parser_cont(struct trace_parser *parser)
1337 {
1338 	return parser->cont;
1339 }
1340 
1341 static inline void trace_parser_clear(struct trace_parser *parser)
1342 {
1343 	parser->cont = false;
1344 	parser->idx = 0;
1345 }
1346 
1347 static inline void trace_parser_fail(struct trace_parser *parser)
1348 {
1349 	parser->fail = true;
1350 }
1351 
1352 extern int trace_parser_get_init(struct trace_parser *parser, int size);
1353 extern void trace_parser_put(struct trace_parser *parser);
1354 extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
1355 	size_t cnt, loff_t *ppos);
1356 
1357 /*
1358  * Only create function graph options if function graph is configured.
1359  */
1360 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1361 # define FGRAPH_FLAGS						\
1362 		C(DISPLAY_GRAPH,	"display-graph"),
1363 #else
1364 # define FGRAPH_FLAGS
1365 #endif
1366 
1367 #ifdef CONFIG_BRANCH_TRACER
1368 # define BRANCH_FLAGS					\
1369 		C(BRANCH,		"branch"),
1370 #else
1371 # define BRANCH_FLAGS
1372 #endif
1373 
1374 #ifdef CONFIG_FUNCTION_TRACER
1375 # define FUNCTION_FLAGS						\
1376 		C(FUNCTION,		"function-trace"),	\
1377 		C(FUNC_FORK,		"function-fork"),
1378 # define FUNCTION_DEFAULT_FLAGS		TRACE_ITER(FUNCTION)
1379 #else
1380 # define FUNCTION_FLAGS
1381 # define FUNCTION_DEFAULT_FLAGS		0UL
1382 # define TRACE_ITER_FUNC_FORK_BIT	-1
1383 #endif
1384 
1385 #ifdef CONFIG_STACKTRACE
1386 # define STACK_FLAGS				\
1387 		C(STACKTRACE,		"stacktrace"),
1388 #else
1389 # define STACK_FLAGS
1390 #endif
1391 
1392 #ifdef CONFIG_FUNCTION_PROFILER
1393 # define PROFILER_FLAGS					\
1394 		C(PROF_TEXT_OFFSET,	"prof-text-offset"),
1395 # ifdef CONFIG_FUNCTION_GRAPH_TRACER
1396 #  define FPROFILE_FLAGS				\
1397 		C(GRAPH_TIME,		"graph-time"),
1398 #  define FPROFILE_DEFAULT_FLAGS	TRACE_ITER(GRAPH_TIME)
1399 # else
1400 #  define FPROFILE_FLAGS
1401 #  define FPROFILE_DEFAULT_FLAGS	0UL
1402 # endif
1403 #else
1404 # define PROFILER_FLAGS
1405 # define FPROFILE_FLAGS
1406 # define FPROFILE_DEFAULT_FLAGS			0UL
1407 # define TRACE_ITER_PROF_TEXT_OFFSET_BIT	-1
1408 #endif
1409 
1410 /*
1411  * trace_iterator_flags is an enumeration that defines bit
1412  * positions into trace_flags that controls the output.
1413  *
1414  * NOTE: These bits must match the trace_options array in
1415  *       trace.c (this macro guarantees it).
1416  */
1417 #define TRACE_FLAGS						\
1418 		C(PRINT_PARENT,		"print-parent"),	\
1419 		C(SYM_OFFSET,		"sym-offset"),		\
1420 		C(SYM_ADDR,		"sym-addr"),		\
1421 		C(VERBOSE,		"verbose"),		\
1422 		C(RAW,			"raw"),			\
1423 		C(HEX,			"hex"),			\
1424 		C(BIN,			"bin"),			\
1425 		C(BLOCK,		"block"),		\
1426 		C(FIELDS,		"fields"),		\
1427 		C(PRINTK,		"trace_printk"),	\
1428 		C(ANNOTATE,		"annotate"),		\
1429 		C(USERSTACKTRACE,	"userstacktrace"),	\
1430 		C(SYM_USEROBJ,		"sym-userobj"),		\
1431 		C(PRINTK_MSGONLY,	"printk-msg-only"),	\
1432 		C(CONTEXT_INFO,		"context-info"),   /* Print pid/cpu/time */ \
1433 		C(LATENCY_FMT,		"latency-format"),	\
1434 		C(RECORD_CMD,		"record-cmd"),		\
1435 		C(RECORD_TGID,		"record-tgid"),		\
1436 		C(OVERWRITE,		"overwrite"),		\
1437 		C(STOP_ON_FREE,		"disable_on_free"),	\
1438 		C(IRQ_INFO,		"irq-info"),		\
1439 		C(MARKERS,		"markers"),		\
1440 		C(EVENT_FORK,		"event-fork"),		\
1441 		C(TRACE_PRINTK,		"trace_printk_dest"),	\
1442 		C(COPY_MARKER,		"copy_trace_marker"),	\
1443 		C(PAUSE_ON_TRACE,	"pause-on-trace"),	\
1444 		C(HASH_PTR,		"hash-ptr"),	/* Print hashed pointer */ \
1445 		C(BITMASK_LIST,		"bitmask-list"),	\
1446 		FUNCTION_FLAGS					\
1447 		FGRAPH_FLAGS					\
1448 		STACK_FLAGS					\
1449 		BRANCH_FLAGS					\
1450 		PROFILER_FLAGS					\
1451 		FPROFILE_FLAGS
1452 
1453 /*
1454  * By defining C, we can make TRACE_FLAGS a list of bit names
1455  * that will define the bits for the flag masks.
1456  */
1457 #undef C
1458 #define C(a, b) TRACE_ITER_##a##_BIT
1459 
1460 enum trace_iterator_bits {
1461 	TRACE_FLAGS
1462 	/* Make sure we don't go more than we have bits for */
1463 	TRACE_ITER_LAST_BIT
1464 };
1465 
1466 /*
1467  * And use TRACE_ITER(flag) to define the bit masks.
1468  */
1469 #define TRACE_ITER(flag)		\
1470 	(TRACE_ITER_##flag##_BIT < 0 ? 0 : 1ULL << (TRACE_ITER_##flag##_BIT))
1471 
1472 /*
1473  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
1474  * control the output of kernel symbols.
1475  */
1476 #define TRACE_ITER_SYM_MASK \
1477 	(TRACE_ITER(PRINT_PARENT)|TRACE_ITER(SYM_OFFSET)|TRACE_ITER(SYM_ADDR))
1478 
1479 extern struct tracer nop_trace;
1480 
1481 #ifdef CONFIG_BRANCH_TRACER
1482 extern int enable_branch_tracing(struct trace_array *tr);
1483 extern void disable_branch_tracing(void);
1484 static inline int trace_branch_enable(struct trace_array *tr)
1485 {
1486 	if (tr->trace_flags & TRACE_ITER(BRANCH))
1487 		return enable_branch_tracing(tr);
1488 	return 0;
1489 }
1490 static inline void trace_branch_disable(void)
1491 {
1492 	/* due to races, always disable */
1493 	disable_branch_tracing();
1494 }
1495 #else
1496 static inline int trace_branch_enable(struct trace_array *tr)
1497 {
1498 	return 0;
1499 }
1500 static inline void trace_branch_disable(void)
1501 {
1502 }
1503 #endif /* CONFIG_BRANCH_TRACER */
1504 
1505 /* set ring buffers to default size if not already done so */
1506 int tracing_update_buffers(struct trace_array *tr);
1507 
1508 union trace_synth_field {
1509 	u8				as_u8;
1510 	u16				as_u16;
1511 	u32				as_u32;
1512 	u64				as_u64;
1513 	struct trace_dynamic_info	as_dynamic;
1514 };
1515 
1516 struct ftrace_event_field {
1517 	struct list_head	link;
1518 	const char		*name;
1519 	const char		*type;
1520 	int			filter_type;
1521 	int			offset;
1522 	int			size;
1523 	unsigned int		is_signed:1;
1524 	unsigned int		needs_test:1;
1525 	int			len;
1526 };
1527 
1528 struct prog_entry;
1529 
1530 struct event_filter {
1531 	struct prog_entry __rcu	*prog;
1532 	char			*filter_string;
1533 };
1534 
1535 struct event_subsystem {
1536 	struct list_head	list;
1537 	const char		*name;
1538 	struct event_filter	*filter;
1539 	int			ref_count;
1540 };
1541 
1542 struct trace_subsystem_dir {
1543 	struct list_head		list;
1544 	struct event_subsystem		*subsystem;
1545 	struct trace_array		*tr;
1546 	struct eventfs_inode		*ei;
1547 	int				ref_count;
1548 	int				nr_events;
1549 };
1550 
1551 void trace_buffer_unlock_commit_regs(struct trace_array *tr,
1552 				     struct trace_buffer *buffer,
1553 				     struct ring_buffer_event *event,
1554 				     unsigned int trcace_ctx,
1555 				     struct pt_regs *regs);
1556 
1557 static inline void trace_buffer_unlock_commit(struct trace_array *tr,
1558 					      struct trace_buffer *buffer,
1559 					      struct ring_buffer_event *event,
1560 					      unsigned int trace_ctx)
1561 {
1562 	trace_buffer_unlock_commit_regs(tr, buffer, event, trace_ctx, NULL);
1563 }
1564 
1565 DECLARE_PER_CPU(bool, trace_taskinfo_save);
1566 int trace_save_cmdline(struct task_struct *tsk);
1567 int trace_create_savedcmd(void);
1568 int trace_alloc_tgid_map(void);
1569 void trace_free_saved_cmdlines_buffer(void);
1570 
1571 extern const struct file_operations tracing_saved_cmdlines_fops;
1572 extern const struct file_operations tracing_saved_tgids_fops;
1573 extern const struct file_operations tracing_saved_cmdlines_size_fops;
1574 
1575 DECLARE_PER_CPU(struct ring_buffer_event *, trace_buffered_event);
1576 DECLARE_PER_CPU(int, trace_buffered_event_cnt);
1577 void trace_buffered_event_disable(void);
1578 void trace_buffered_event_enable(void);
1579 
1580 void early_enable_events(struct trace_array *tr, char *buf, bool disable_first);
1581 
1582 struct trace_user_buf;
1583 struct trace_user_buf_info {
1584 	struct trace_user_buf __percpu	*tbuf;
1585 	size_t				size;
1586 	int				ref;
1587 };
1588 
1589 typedef int (*trace_user_buf_copy)(char *dst, const char __user *src,
1590 				  size_t size, void *data);
1591 int trace_user_fault_init(struct trace_user_buf_info *tinfo, size_t size);
1592 int trace_user_fault_get(struct trace_user_buf_info *tinfo);
1593 int trace_user_fault_put(struct trace_user_buf_info *tinfo);
1594 void trace_user_fault_destroy(struct trace_user_buf_info *tinfo);
1595 char *trace_user_fault_read(struct trace_user_buf_info *tinfo,
1596 			    const char __user *ptr, size_t size,
1597 			    trace_user_buf_copy copy_func, void *data);
1598 
1599 static __always_inline void
1600 trace_event_setup(struct ring_buffer_event *event,
1601 		  int type, unsigned int trace_ctx)
1602 {
1603 	struct trace_entry *ent = ring_buffer_event_data(event);
1604 
1605 	tracing_generic_entry_update(ent, type, trace_ctx);
1606 }
1607 
1608 static __always_inline struct ring_buffer_event *
1609 __trace_buffer_lock_reserve(struct trace_buffer *buffer,
1610 			  int type,
1611 			  unsigned long len,
1612 			  unsigned int trace_ctx)
1613 {
1614 	struct ring_buffer_event *event;
1615 
1616 	event = ring_buffer_lock_reserve(buffer, len);
1617 	if (event != NULL)
1618 		trace_event_setup(event, type, trace_ctx);
1619 
1620 	return event;
1621 }
1622 
1623 static __always_inline void
1624 __buffer_unlock_commit(struct trace_buffer *buffer, struct ring_buffer_event *event)
1625 {
1626 	__this_cpu_write(trace_taskinfo_save, true);
1627 
1628 	/* If this is the temp buffer, we need to commit fully */
1629 	if (this_cpu_read(trace_buffered_event) == event) {
1630 		/* Length is in event->array[0] */
1631 		ring_buffer_write(buffer, event->array[0], &event->array[1]);
1632 		/* Release the temp buffer */
1633 		this_cpu_dec(trace_buffered_event_cnt);
1634 		/* ring_buffer_unlock_commit() enables preemption */
1635 		preempt_enable_notrace();
1636 	} else
1637 		ring_buffer_unlock_commit(buffer);
1638 }
1639 
1640 static inline void
1641 __trace_event_discard_commit(struct trace_buffer *buffer,
1642 			     struct ring_buffer_event *event)
1643 {
1644 	if (this_cpu_read(trace_buffered_event) == event) {
1645 		/* Simply release the temp buffer and enable preemption */
1646 		this_cpu_dec(trace_buffered_event_cnt);
1647 		preempt_enable_notrace();
1648 		return;
1649 	}
1650 	/* ring_buffer_discard_commit() enables preemption */
1651 	ring_buffer_discard_commit(buffer, event);
1652 }
1653 
1654 /*
1655  * Helper function for event_trigger_unlock_commit{_regs}().
1656  * If there are event triggers attached to this event that requires
1657  * filtering against its fields, then they will be called as the
1658  * entry already holds the field information of the current event.
1659  *
1660  * It also checks if the event should be discarded or not.
1661  * It is to be discarded if the event is soft disabled and the
1662  * event was only recorded to process triggers, or if the event
1663  * filter is active and this event did not match the filters.
1664  *
1665  * Returns true if the event is discarded, false otherwise.
1666  */
1667 static inline bool
1668 __event_trigger_test_discard(struct trace_event_file *file,
1669 			     struct trace_buffer *buffer,
1670 			     struct ring_buffer_event *event,
1671 			     void *entry,
1672 			     enum event_trigger_type *tt)
1673 {
1674 	unsigned long eflags = file->flags;
1675 
1676 	if (eflags & EVENT_FILE_FL_TRIGGER_COND)
1677 		*tt = event_triggers_call(file, buffer, entry, event);
1678 
1679 	if (likely(!(file->flags & (EVENT_FILE_FL_SOFT_DISABLED |
1680 				    EVENT_FILE_FL_FILTERED |
1681 				    EVENT_FILE_FL_PID_FILTER))))
1682 		return false;
1683 
1684 	if (file->flags & EVENT_FILE_FL_SOFT_DISABLED)
1685 		goto discard;
1686 
1687 	if (file->flags & EVENT_FILE_FL_FILTERED &&
1688 	    !filter_match_preds(file->filter, entry))
1689 		goto discard;
1690 
1691 	if ((file->flags & EVENT_FILE_FL_PID_FILTER) &&
1692 	    trace_event_ignore_this_pid(file))
1693 		goto discard;
1694 
1695 	return false;
1696  discard:
1697 	__trace_event_discard_commit(buffer, event);
1698 	return true;
1699 }
1700 
1701 /**
1702  * event_trigger_unlock_commit - handle triggers and finish event commit
1703  * @file: The file pointer associated with the event
1704  * @buffer: The ring buffer that the event is being written to
1705  * @event: The event meta data in the ring buffer
1706  * @entry: The event itself
1707  * @trace_ctx: The tracing context flags.
1708  *
1709  * This is a helper function to handle triggers that require data
1710  * from the event itself. It also tests the event against filters and
1711  * if the event is soft disabled and should be discarded.
1712  */
1713 static inline void
1714 event_trigger_unlock_commit(struct trace_event_file *file,
1715 			    struct trace_buffer *buffer,
1716 			    struct ring_buffer_event *event,
1717 			    void *entry, unsigned int trace_ctx)
1718 {
1719 	enum event_trigger_type tt = ETT_NONE;
1720 
1721 	if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1722 		trace_buffer_unlock_commit(file->tr, buffer, event, trace_ctx);
1723 
1724 	if (tt)
1725 		event_triggers_post_call(file, tt);
1726 }
1727 
1728 #define FILTER_PRED_INVALID	((unsigned short)-1)
1729 #define FILTER_PRED_IS_RIGHT	(1 << 15)
1730 #define FILTER_PRED_FOLD	(1 << 15)
1731 
1732 /*
1733  * The max preds is the size of unsigned short with
1734  * two flags at the MSBs. One bit is used for both the IS_RIGHT
1735  * and FOLD flags. The other is reserved.
1736  *
1737  * 2^14 preds is way more than enough.
1738  */
1739 #define MAX_FILTER_PRED		16384
1740 
1741 struct filter_pred;
1742 struct regex;
1743 
1744 typedef int (*regex_match_func)(char *str, struct regex *r, int len);
1745 
1746 enum regex_type {
1747 	MATCH_FULL = 0,
1748 	MATCH_FRONT_ONLY,
1749 	MATCH_MIDDLE_ONLY,
1750 	MATCH_END_ONLY,
1751 	MATCH_GLOB,
1752 	MATCH_INDEX,
1753 };
1754 
1755 struct regex {
1756 	char			pattern[MAX_FILTER_STR_VAL];
1757 	int			len;
1758 	int			field_len;
1759 	regex_match_func	match;
1760 };
1761 
1762 static inline bool is_string_field(struct ftrace_event_field *field)
1763 {
1764 	return field->filter_type == FILTER_DYN_STRING ||
1765 	       field->filter_type == FILTER_RDYN_STRING ||
1766 	       field->filter_type == FILTER_STATIC_STRING ||
1767 	       field->filter_type == FILTER_PTR_STRING ||
1768 	       field->filter_type == FILTER_COMM;
1769 }
1770 
1771 static inline bool is_function_field(struct ftrace_event_field *field)
1772 {
1773 	return field->filter_type == FILTER_TRACE_FN;
1774 }
1775 
1776 extern enum regex_type
1777 filter_parse_regex(char *buff, int len, char **search, int *not);
1778 extern void print_event_filter(struct trace_event_file *file,
1779 			       struct trace_seq *s);
1780 extern int apply_event_filter(struct trace_event_file *file,
1781 			      char *filter_string);
1782 extern int apply_subsystem_event_filter(struct trace_subsystem_dir *dir,
1783 					char *filter_string);
1784 extern void print_subsystem_event_filter(struct event_subsystem *system,
1785 					 struct trace_seq *s);
1786 extern int filter_assign_type(const char *type);
1787 extern int create_event_filter(struct trace_array *tr,
1788 			       struct trace_event_call *call,
1789 			       char *filter_str, bool set_str,
1790 			       struct event_filter **filterp);
1791 extern void free_event_filter(struct event_filter *filter);
1792 
1793 struct ftrace_event_field *
1794 trace_find_event_field(struct trace_event_call *call, char *name);
1795 
1796 extern void trace_event_enable_cmd_record(bool enable);
1797 extern void trace_event_enable_tgid_record(bool enable);
1798 
1799 extern int event_trace_init(void);
1800 extern int init_events(void);
1801 extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
1802 extern int event_trace_del_tracer(struct trace_array *tr);
1803 extern void __trace_early_add_events(struct trace_array *tr);
1804 
1805 extern struct trace_event_file *__find_event_file(struct trace_array *tr,
1806 						  const char *system,
1807 						  const char *event);
1808 extern struct trace_event_file *find_event_file(struct trace_array *tr,
1809 						const char *system,
1810 						const char *event);
1811 
1812 static inline void *event_file_data(struct file *filp)
1813 {
1814 	return READ_ONCE(file_inode(filp)->i_private);
1815 }
1816 
1817 extern struct mutex event_mutex;
1818 extern struct list_head ftrace_events;
1819 
1820 /*
1821  * When the trace_event_file is the filp->i_private pointer,
1822  * it must be taken under the event_mutex lock, and then checked
1823  * if the EVENT_FILE_FL_FREED flag is set. If it is, then the
1824  * data pointed to by the trace_event_file can not be trusted.
1825  *
1826  * Use the event_file_file() to access the trace_event_file from
1827  * the filp the first time under the event_mutex and check for
1828  * NULL. If it is needed to be retrieved again and the event_mutex
1829  * is still held, then the event_file_data() can be used and it
1830  * is guaranteed to be valid.
1831  */
1832 static inline struct trace_event_file *event_file_file(struct file *filp)
1833 {
1834 	struct trace_event_file *file;
1835 
1836 	lockdep_assert_held(&event_mutex);
1837 	file = READ_ONCE(file_inode(filp)->i_private);
1838 	if (!file || file->flags & EVENT_FILE_FL_FREED)
1839 		return NULL;
1840 	return file;
1841 }
1842 
1843 extern const struct file_operations event_trigger_fops;
1844 extern const struct file_operations event_hist_fops;
1845 extern const struct file_operations event_hist_debug_fops;
1846 extern const struct file_operations event_inject_fops;
1847 
1848 #ifdef CONFIG_HIST_TRIGGERS
1849 extern int register_trigger_hist_cmd(void);
1850 extern int register_trigger_hist_enable_disable_cmds(void);
1851 #else
1852 static inline int register_trigger_hist_cmd(void) { return 0; }
1853 static inline int register_trigger_hist_enable_disable_cmds(void) { return 0; }
1854 #endif
1855 
1856 extern int register_trigger_cmds(void);
1857 extern void clear_event_triggers(struct trace_array *tr);
1858 
1859 enum {
1860 	EVENT_TRIGGER_FL_PROBE		= BIT(0),
1861 	EVENT_TRIGGER_FL_COUNT		= BIT(1),
1862 };
1863 
1864 struct event_trigger_data {
1865 	unsigned long			count;
1866 	int				ref;
1867 	int				flags;
1868 	struct event_command		*cmd_ops;
1869 	struct event_filter __rcu	*filter;
1870 	char				*filter_str;
1871 	void				*private_data;
1872 	bool				paused;
1873 	bool				paused_tmp;
1874 	struct list_head		list;
1875 	char				*name;
1876 	struct list_head		named_list;
1877 	struct event_trigger_data	*named_data;
1878 	struct llist_node		llist;
1879 };
1880 
1881 /* Avoid typos */
1882 #define ENABLE_EVENT_STR	"enable_event"
1883 #define DISABLE_EVENT_STR	"disable_event"
1884 #define ENABLE_HIST_STR		"enable_hist"
1885 #define DISABLE_HIST_STR	"disable_hist"
1886 
1887 struct enable_trigger_data {
1888 	struct trace_event_file		*file;
1889 	bool				enable;
1890 	bool				hist;
1891 };
1892 
1893 bool event_trigger_count(struct event_trigger_data *data,
1894 			 struct trace_buffer *buffer,  void *rec,
1895 			 struct ring_buffer_event *event);
1896 
1897 extern int event_enable_trigger_print(struct seq_file *m,
1898 				      struct event_trigger_data *data);
1899 extern void event_enable_trigger_free(struct event_trigger_data *data);
1900 extern int event_enable_trigger_parse(struct event_command *cmd_ops,
1901 				      struct trace_event_file *file,
1902 				      char *glob, char *cmd,
1903 				      char *param_and_filter);
1904 extern int event_enable_register_trigger(char *glob,
1905 					 struct event_trigger_data *data,
1906 					 struct trace_event_file *file);
1907 extern void event_enable_unregister_trigger(char *glob,
1908 					    struct event_trigger_data *test,
1909 					    struct trace_event_file *file);
1910 extern struct event_trigger_data *
1911 trigger_data_alloc(struct event_command *cmd_ops, char *cmd, char *param,
1912 		   void *private_data);
1913 extern void trigger_data_free(struct event_trigger_data *data);
1914 extern int event_trigger_init(struct event_trigger_data *data);
1915 extern int trace_event_trigger_enable_disable(struct trace_event_file *file,
1916 					      int trigger_enable);
1917 extern void update_cond_flag(struct trace_event_file *file);
1918 extern int set_trigger_filter(char *filter_str,
1919 			      struct event_trigger_data *trigger_data,
1920 			      struct trace_event_file *file);
1921 extern struct event_trigger_data *find_named_trigger(const char *name);
1922 extern bool is_named_trigger(struct event_trigger_data *test);
1923 extern int save_named_trigger(const char *name,
1924 			      struct event_trigger_data *data);
1925 extern void del_named_trigger(struct event_trigger_data *data);
1926 extern void pause_named_trigger(struct event_trigger_data *data);
1927 extern void unpause_named_trigger(struct event_trigger_data *data);
1928 extern void set_named_trigger_data(struct event_trigger_data *data,
1929 				   struct event_trigger_data *named_data);
1930 extern struct event_trigger_data *
1931 get_named_trigger_data(struct event_trigger_data *data);
1932 extern int register_event_command(struct event_command *cmd);
1933 extern int unregister_event_command(struct event_command *cmd);
1934 extern int register_trigger_hist_enable_disable_cmds(void);
1935 extern bool event_trigger_check_remove(const char *glob);
1936 extern bool event_trigger_empty_param(const char *param);
1937 extern int event_trigger_separate_filter(char *param_and_filter, char **param,
1938 					 char **filter, bool param_required);
1939 extern int event_trigger_parse_num(char *trigger,
1940 				   struct event_trigger_data *trigger_data);
1941 extern int event_trigger_set_filter(struct event_command *cmd_ops,
1942 				    struct trace_event_file *file,
1943 				    char *param,
1944 				    struct event_trigger_data *trigger_data);
1945 extern void event_trigger_reset_filter(struct event_command *cmd_ops,
1946 				       struct event_trigger_data *trigger_data);
1947 extern int event_trigger_register(struct event_command *cmd_ops,
1948 				  struct trace_event_file *file,
1949 				  char *glob,
1950 				  struct event_trigger_data *trigger_data);
1951 extern void event_trigger_unregister(struct event_command *cmd_ops,
1952 				     struct trace_event_file *file,
1953 				     char *glob,
1954 				     struct event_trigger_data *trigger_data);
1955 
1956 extern void event_file_get(struct trace_event_file *file);
1957 extern void event_file_put(struct trace_event_file *file);
1958 
1959 /**
1960  * struct event_command - callbacks and data members for event commands
1961  *
1962  * Event commands are invoked by users by writing the command name
1963  * into the 'trigger' file associated with a trace event.  The
1964  * parameters associated with a specific invocation of an event
1965  * command are used to create an event trigger instance, which is
1966  * added to the list of trigger instances associated with that trace
1967  * event.  When the event is hit, the set of triggers associated with
1968  * that event is invoked.
1969  *
1970  * The data members in this structure provide per-event command data
1971  * for various event commands.
1972  *
1973  * All the data members below, except for @post_trigger, must be set
1974  * for each event command.
1975  *
1976  * @name: The unique name that identifies the event command.  This is
1977  *	the name used when setting triggers via trigger files.
1978  *
1979  * @trigger_type: A unique id that identifies the event command
1980  *	'type'.  This value has two purposes, the first to ensure that
1981  *	only one trigger of the same type can be set at a given time
1982  *	for a particular event e.g. it doesn't make sense to have both
1983  *	a traceon and traceoff trigger attached to a single event at
1984  *	the same time, so traceon and traceoff have the same type
1985  *	though they have different names.  The @trigger_type value is
1986  *	also used as a bit value for deferring the actual trigger
1987  *	action until after the current event is finished.  Some
1988  *	commands need to do this if they themselves log to the trace
1989  *	buffer (see the @post_trigger() member below).  @trigger_type
1990  *	values are defined by adding new values to the trigger_type
1991  *	enum in include/linux/trace_events.h.
1992  *
1993  * @flags: See the enum event_command_flags below.
1994  *
1995  * All the methods below, except for @set_filter() and @unreg_all(),
1996  * must be implemented.
1997  *
1998  * @parse: The callback function responsible for parsing and
1999  *	registering the trigger written to the 'trigger' file by the
2000  *	user.  It allocates the trigger instance and registers it with
2001  *	the appropriate trace event.  It makes use of the other
2002  *	event_command callback functions to orchestrate this, and is
2003  *	usually implemented by the generic utility function
2004  *	@event_trigger_callback() (see trace_event_triggers.c).
2005  *
2006  * @reg: Adds the trigger to the list of triggers associated with the
2007  *	event, and enables the event trigger itself, after
2008  *	initializing it (via the event_command @init() function).
2009  *	This is also where commands can use the @trigger_type value to
2010  *	make the decision as to whether or not multiple instances of
2011  *	the trigger should be allowed.  This is usually implemented by
2012  *	the generic utility function @register_trigger() (see
2013  *	trace_event_triggers.c).
2014  *
2015  * @unreg: Removes the trigger from the list of triggers associated
2016  *	with the event, and disables the event trigger itself, after
2017  *	initializing it (via the event_command @free() function).
2018  *	This is usually implemented by the generic utility function
2019  *	@unregister_trigger() (see trace_event_triggers.c).
2020  *
2021  * @unreg_all: An optional function called to remove all the triggers
2022  *	from the list of triggers associated with the event.  Called
2023  *	when a trigger file is opened in truncate mode.
2024  *
2025  * @set_filter: An optional function called to parse and set a filter
2026  *	for the trigger.  If no @set_filter() method is set for the
2027  *	event command, filters set by the user for the command will be
2028  *	ignored.  This is usually implemented by the generic utility
2029  *	function @set_trigger_filter() (see trace_event_triggers.c).
2030  *
2031  * All the methods below, except for @init() and @free(), must be
2032  * implemented.
2033  *
2034  * @trigger: The trigger 'probe' function called when the triggering
2035  *	event occurs.  The data passed into this callback is the data
2036  *	that was supplied to the event_command @reg() function that
2037  *	registered the trigger (see struct event_command) along with
2038  *	the trace record, rec.
2039  *
2040  * @count_func: If defined and a numeric parameter is passed to the
2041  *	trigger, then this function will be called before @trigger
2042  *	is called. If this function returns false, then @trigger is not
2043  *	executed.
2044  *
2045  * @init: An optional initialization function called for the trigger
2046  *	when the trigger is registered (via the event_command reg()
2047  *	function).  This can be used to perform per-trigger
2048  *	initialization such as incrementing a per-trigger reference
2049  *	count, for instance.  This is usually implemented by the
2050  *	generic utility function @event_trigger_init() (see
2051  *	trace_event_triggers.c).
2052  *
2053  * @free: An optional de-initialization function called for the
2054  *	trigger when the trigger is unregistered (via the
2055  *	event_command @reg() function).  This can be used to perform
2056  *	per-trigger de-initialization such as decrementing a
2057  *	per-trigger reference count and freeing corresponding trigger
2058  *	data, for instance.  This is usually implemented by the
2059  *	generic utility function @event_trigger_free() (see
2060  *	trace_event_triggers.c).
2061  *
2062  * @print: The callback function invoked to have the trigger print
2063  *	itself.  This is usually implemented by a wrapper function
2064  *	that calls the generic utility function @event_trigger_print()
2065  *	(see trace_event_triggers.c).
2066  */
2067 struct event_command {
2068 	struct list_head	list;
2069 	char			*name;
2070 	enum event_trigger_type	trigger_type;
2071 	int			flags;
2072 	int			(*parse)(struct event_command *cmd_ops,
2073 					 struct trace_event_file *file,
2074 					 char *glob, char *cmd,
2075 					 char *param_and_filter);
2076 	int			(*reg)(char *glob,
2077 				       struct event_trigger_data *data,
2078 				       struct trace_event_file *file);
2079 	void			(*unreg)(char *glob,
2080 					 struct event_trigger_data *data,
2081 					 struct trace_event_file *file);
2082 	void			(*unreg_all)(struct trace_event_file *file);
2083 	int			(*set_filter)(char *filter_str,
2084 					      struct event_trigger_data *data,
2085 					      struct trace_event_file *file);
2086 	void			(*trigger)(struct event_trigger_data *data,
2087 					   struct trace_buffer *buffer,
2088 					   void *rec,
2089 					   struct ring_buffer_event *rbe);
2090 	bool			(*count_func)(struct event_trigger_data *data,
2091 					      struct trace_buffer *buffer,
2092 					      void *rec,
2093 					      struct ring_buffer_event *rbe);
2094 	int			(*init)(struct event_trigger_data *data);
2095 	void			(*free)(struct event_trigger_data *data);
2096 	int			(*print)(struct seq_file *m,
2097 					 struct event_trigger_data *data);
2098 };
2099 
2100 /**
2101  * enum event_command_flags - flags for struct event_command
2102  *
2103  * @POST_TRIGGER: A flag that says whether or not this command needs
2104  *	to have its action delayed until after the current event has
2105  *	been closed.  Some triggers need to avoid being invoked while
2106  *	an event is currently in the process of being logged, since
2107  *	the trigger may itself log data into the trace buffer.  Thus
2108  *	we make sure the current event is committed before invoking
2109  *	those triggers.  To do that, the trigger invocation is split
2110  *	in two - the first part checks the filter using the current
2111  *	trace record; if a command has the @post_trigger flag set, it
2112  *	sets a bit for itself in the return value, otherwise it
2113  *	directly invokes the trigger.  Once all commands have been
2114  *	either invoked or set their return flag, the current record is
2115  *	either committed or discarded.  At that point, if any commands
2116  *	have deferred their triggers, those commands are finally
2117  *	invoked following the close of the current event.  In other
2118  *	words, if the event_command @func() probe implementation
2119  *	itself logs to the trace buffer, this flag should be set,
2120  *	otherwise it can be left unspecified.
2121  *
2122  * @NEEDS_REC: A flag that says whether or not this command needs
2123  *	access to the trace record in order to perform its function,
2124  *	regardless of whether or not it has a filter associated with
2125  *	it (filters make a trigger require access to the trace record
2126  *	but are not always present).
2127  */
2128 enum event_command_flags {
2129 	EVENT_CMD_FL_POST_TRIGGER	= 1,
2130 	EVENT_CMD_FL_NEEDS_REC		= 2,
2131 };
2132 
2133 static inline bool event_command_post_trigger(struct event_command *cmd_ops)
2134 {
2135 	return cmd_ops->flags & EVENT_CMD_FL_POST_TRIGGER;
2136 }
2137 
2138 static inline bool event_command_needs_rec(struct event_command *cmd_ops)
2139 {
2140 	return cmd_ops->flags & EVENT_CMD_FL_NEEDS_REC;
2141 }
2142 
2143 extern int trace_event_enable_disable(struct trace_event_file *file,
2144 				      int enable, int soft_disable);
2145 extern int tracing_alloc_snapshot(void);
2146 extern void tracing_snapshot_cond(struct trace_array *tr, void *cond_data);
2147 extern int tracing_snapshot_cond_enable(struct trace_array *tr, void *cond_data, cond_update_fn_t update);
2148 
2149 extern int tracing_snapshot_cond_disable(struct trace_array *tr);
2150 extern void *tracing_cond_snapshot_data(struct trace_array *tr);
2151 
2152 extern const char *__start___trace_bprintk_fmt[];
2153 extern const char *__stop___trace_bprintk_fmt[];
2154 
2155 extern const char *__start___tracepoint_str[];
2156 extern const char *__stop___tracepoint_str[];
2157 
2158 void trace_printk_control(bool enabled);
2159 void trace_printk_start_comm(void);
2160 void trace_printk_start_stop_comm(int enabled);
2161 int trace_keep_overwrite(struct tracer *tracer, u64 mask, int set);
2162 int set_tracer_flag(struct trace_array *tr, u64 mask, int enabled);
2163 
2164 /* Used from boot time tracer */
2165 extern int trace_set_options(struct trace_array *tr, char *option);
2166 extern int tracing_set_tracer(struct trace_array *tr, const char *buf);
2167 extern ssize_t tracing_resize_ring_buffer(struct trace_array *tr,
2168 					  unsigned long size, int cpu_id);
2169 extern int tracing_set_cpumask(struct trace_array *tr,
2170 				cpumask_var_t tracing_cpumask_new);
2171 
2172 
2173 #define MAX_EVENT_NAME_LEN	64
2174 
2175 extern ssize_t trace_parse_run_command(struct file *file,
2176 		const char __user *buffer, size_t count, loff_t *ppos,
2177 		int (*createfn)(const char *));
2178 
2179 extern unsigned int err_pos(char *cmd, const char *str);
2180 extern void tracing_log_err(struct trace_array *tr,
2181 			    const char *loc, const char *cmd,
2182 			    const char **errs, u8 type, u16 pos);
2183 
2184 /*
2185  * Normal trace_printk() and friends allocates special buffers
2186  * to do the manipulation, as well as saves the print formats
2187  * into sections to display. But the trace infrastructure wants
2188  * to use these without the added overhead at the price of being
2189  * a bit slower (used mainly for warnings, where we don't care
2190  * about performance). The internal_trace_puts() is for such
2191  * a purpose.
2192  */
2193 #define internal_trace_puts(str) __trace_puts(_THIS_IP_, str)
2194 
2195 #undef FTRACE_ENTRY
2196 #define FTRACE_ENTRY(call, struct_name, id, tstruct, print)	\
2197 	extern struct trace_event_call					\
2198 	__aligned(4) event_##call;
2199 #undef FTRACE_ENTRY_DUP
2200 #define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print)	\
2201 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
2202 #undef FTRACE_ENTRY_PACKED
2203 #define FTRACE_ENTRY_PACKED(call, struct_name, id, tstruct, print) \
2204 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
2205 
2206 #include "trace_entries.h"
2207 
2208 #if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_FUNCTION_TRACER)
2209 int perf_ftrace_event_register(struct trace_event_call *call,
2210 			       enum trace_reg type, void *data);
2211 #else
2212 #define perf_ftrace_event_register NULL
2213 #endif
2214 
2215 #ifdef CONFIG_FTRACE_SYSCALLS
2216 void init_ftrace_syscalls(void);
2217 const char *get_syscall_name(int syscall);
2218 #else
2219 static inline void init_ftrace_syscalls(void) { }
2220 static inline const char *get_syscall_name(int syscall)
2221 {
2222 	return NULL;
2223 }
2224 #endif
2225 
2226 #ifdef CONFIG_EVENT_TRACING
2227 void trace_event_init(void);
2228 void trace_event_update_all(struct trace_eval_map **map, int len);
2229 /* Used from boot time tracer */
2230 extern int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set);
2231 extern int trigger_process_regex(struct trace_event_file *file, char *buff);
2232 #else
2233 static inline void __init trace_event_init(void) { }
2234 static inline void trace_event_update_all(struct trace_eval_map **map, int len) { }
2235 #endif
2236 
2237 #ifdef CONFIG_TRACER_SNAPSHOT
2238 void tracing_snapshot_instance(struct trace_array *tr);
2239 int tracing_alloc_snapshot_instance(struct trace_array *tr);
2240 int tracing_arm_snapshot(struct trace_array *tr);
2241 void tracing_disarm_snapshot(struct trace_array *tr);
2242 #else
2243 static inline void tracing_snapshot_instance(struct trace_array *tr) { }
2244 static inline int tracing_alloc_snapshot_instance(struct trace_array *tr)
2245 {
2246 	return 0;
2247 }
2248 static inline int tracing_arm_snapshot(struct trace_array *tr) { return 0; }
2249 static inline void tracing_disarm_snapshot(struct trace_array *tr) { }
2250 #endif
2251 
2252 #ifdef CONFIG_PREEMPT_TRACER
2253 void tracer_preempt_on(unsigned long a0, unsigned long a1);
2254 void tracer_preempt_off(unsigned long a0, unsigned long a1);
2255 #else
2256 static inline void tracer_preempt_on(unsigned long a0, unsigned long a1) { }
2257 static inline void tracer_preempt_off(unsigned long a0, unsigned long a1) { }
2258 #endif
2259 #ifdef CONFIG_IRQSOFF_TRACER
2260 void tracer_hardirqs_on(unsigned long a0, unsigned long a1);
2261 void tracer_hardirqs_off(unsigned long a0, unsigned long a1);
2262 #else
2263 static inline void tracer_hardirqs_on(unsigned long a0, unsigned long a1) { }
2264 static inline void tracer_hardirqs_off(unsigned long a0, unsigned long a1) { }
2265 #endif
2266 
2267 /*
2268  * Reset the state of the trace_iterator so that it can read consumed data.
2269  * Normally, the trace_iterator is used for reading the data when it is not
2270  * consumed, and must retain state.
2271  */
2272 static __always_inline void trace_iterator_reset(struct trace_iterator *iter)
2273 {
2274 	memset_startat(iter, 0, seq);
2275 	iter->pos = -1;
2276 }
2277 
2278 /* Check the name is good for event/group/fields */
2279 static inline bool __is_good_name(const char *name, bool hash_ok)
2280 {
2281 	if (!isalpha(*name) && *name != '_' && (!hash_ok || *name != '-'))
2282 		return false;
2283 	while (*++name != '\0') {
2284 		if (!isalpha(*name) && !isdigit(*name) && *name != '_' &&
2285 		    (!hash_ok || *name != '-'))
2286 			return false;
2287 	}
2288 	return true;
2289 }
2290 
2291 /* Check the name is good for event/group/fields */
2292 static inline bool is_good_name(const char *name)
2293 {
2294 	return __is_good_name(name, false);
2295 }
2296 
2297 /* Check the name is good for system */
2298 static inline bool is_good_system_name(const char *name)
2299 {
2300 	return __is_good_name(name, true);
2301 }
2302 
2303 /* Convert certain expected symbols into '_' when generating event names */
2304 static inline void sanitize_event_name(char *name)
2305 {
2306 	while (*name++ != '\0')
2307 		if (*name == ':' || *name == '.' || *name == '*')
2308 			*name = '_';
2309 }
2310 
2311 #ifdef CONFIG_STACKTRACE
2312 void __ftrace_trace_stack(struct trace_array *tr,
2313 			  struct trace_buffer *buffer,
2314 			  unsigned int trace_ctx,
2315 			  int skip, struct pt_regs *regs);
2316 
2317 static __always_inline void ftrace_trace_stack(struct trace_array *tr,
2318 					       struct trace_buffer *buffer,
2319 					       unsigned int trace_ctx,
2320 					       int skip, struct pt_regs *regs)
2321 {
2322 	if (!(tr->trace_flags & TRACE_ITER(STACKTRACE)))
2323 		return;
2324 
2325 	__ftrace_trace_stack(tr, buffer, trace_ctx, skip, regs);
2326 }
2327 #else
2328 static inline void __ftrace_trace_stack(struct trace_array *tr,
2329 					struct trace_buffer *buffer,
2330 					unsigned int trace_ctx,
2331 					int skip, struct pt_regs *regs)
2332 {
2333 }
2334 static inline void ftrace_trace_stack(struct trace_array *tr,
2335 				      struct trace_buffer *buffer,
2336 				      unsigned long trace_ctx,
2337 				      int skip, struct pt_regs *regs)
2338 {
2339 }
2340 #endif
2341 
2342 /*
2343  * This is a generic way to read and write a u64 value from a file in tracefs.
2344  *
2345  * The value is stored on the variable pointed by *val. The value needs
2346  * to be at least *min and at most *max. The write is protected by an
2347  * existing *lock.
2348  */
2349 struct trace_min_max_param {
2350 	struct mutex	*lock;
2351 	u64		*val;
2352 	u64		*min;
2353 	u64		*max;
2354 };
2355 
2356 #define U64_STR_SIZE		24	/* 20 digits max */
2357 
2358 extern const struct file_operations trace_min_max_fops;
2359 
2360 #ifdef CONFIG_RV
2361 extern int rv_init_interface(void);
2362 #else
2363 static inline int rv_init_interface(void)
2364 {
2365 	return 0;
2366 }
2367 #endif
2368 
2369 /*
2370  * This is used only to distinguish
2371  * function address from trampoline code.
2372  * So this value has no meaning.
2373  */
2374 #define FTRACE_TRAMPOLINE_MARKER  ((unsigned long) INT_MAX)
2375 
2376 /*
2377  * This is used to get the address of the args array based on
2378  * the type of the entry.
2379  */
2380 #define FGRAPH_ENTRY_ARGS(e)						\
2381 	({								\
2382 		unsigned long *_args;					\
2383 		struct ftrace_graph_ent_entry *_e = e;			\
2384 									\
2385 		if (IS_ENABLED(CONFIG_FUNCTION_GRAPH_RETADDR) &&	\
2386 			e->ent.type == TRACE_GRAPH_RETADDR_ENT) {	\
2387 			struct fgraph_retaddr_ent_entry *_re;		\
2388 									\
2389 			_re = (typeof(_re))_e;				\
2390 			_args = _re->args;				\
2391 		} else {						\
2392 			_args = _e->args;				\
2393 		}							\
2394 		_args;							\
2395 	})
2396 
2397 #endif /* _LINUX_KERNEL_TRACE_H */
2398