xref: /openbmc/linux/kernel/trace/trace.h (revision babbdf5b)
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 
24 #ifdef CONFIG_FTRACE_SYSCALLS
25 #include <asm/unistd.h>		/* For NR_SYSCALLS	     */
26 #include <asm/syscall.h>	/* some archs define it here */
27 #endif
28 
29 enum trace_type {
30 	__TRACE_FIRST_TYPE = 0,
31 
32 	TRACE_FN,
33 	TRACE_CTX,
34 	TRACE_WAKE,
35 	TRACE_STACK,
36 	TRACE_PRINT,
37 	TRACE_BPRINT,
38 	TRACE_MMIO_RW,
39 	TRACE_MMIO_MAP,
40 	TRACE_BRANCH,
41 	TRACE_GRAPH_RET,
42 	TRACE_GRAPH_ENT,
43 	TRACE_USER_STACK,
44 	TRACE_BLK,
45 	TRACE_BPUTS,
46 	TRACE_HWLAT,
47 	TRACE_RAW_DATA,
48 	TRACE_FUNC_REPEATS,
49 
50 	__TRACE_LAST_TYPE,
51 };
52 
53 
54 #undef __field
55 #define __field(type, item)		type	item;
56 
57 #undef __field_fn
58 #define __field_fn(type, item)		type	item;
59 
60 #undef __field_struct
61 #define __field_struct(type, item)	__field(type, item)
62 
63 #undef __field_desc
64 #define __field_desc(type, container, item)
65 
66 #undef __field_packed
67 #define __field_packed(type, container, item)
68 
69 #undef __array
70 #define __array(type, item, size)	type	item[size];
71 
72 #undef __array_desc
73 #define __array_desc(type, container, item, size)
74 
75 #undef __dynamic_array
76 #define __dynamic_array(type, item)	type	item[];
77 
78 #undef F_STRUCT
79 #define F_STRUCT(args...)		args
80 
81 #undef FTRACE_ENTRY
82 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print)		\
83 	struct struct_name {						\
84 		struct trace_entry	ent;				\
85 		tstruct							\
86 	}
87 
88 #undef FTRACE_ENTRY_DUP
89 #define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk)
90 
91 #undef FTRACE_ENTRY_REG
92 #define FTRACE_ENTRY_REG(name, struct_name, id, tstruct, print,	regfn)	\
93 	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print))
94 
95 #undef FTRACE_ENTRY_PACKED
96 #define FTRACE_ENTRY_PACKED(name, struct_name, id, tstruct, print)	\
97 	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print)) __packed
98 
99 #include "trace_entries.h"
100 
101 /* Use this for memory failure errors */
102 #define MEM_FAIL(condition, fmt, ...) ({			\
103 	static bool __section(".data.once") __warned;		\
104 	int __ret_warn_once = !!(condition);			\
105 								\
106 	if (unlikely(__ret_warn_once && !__warned)) {		\
107 		__warned = true;				\
108 		pr_err("ERROR: " fmt, ##__VA_ARGS__);		\
109 	}							\
110 	unlikely(__ret_warn_once);				\
111 })
112 
113 /*
114  * syscalls are special, and need special handling, this is why
115  * they are not included in trace_entries.h
116  */
117 struct syscall_trace_enter {
118 	struct trace_entry	ent;
119 	int			nr;
120 	unsigned long		args[];
121 };
122 
123 struct syscall_trace_exit {
124 	struct trace_entry	ent;
125 	int			nr;
126 	long			ret;
127 };
128 
129 struct kprobe_trace_entry_head {
130 	struct trace_entry	ent;
131 	unsigned long		ip;
132 };
133 
134 struct kretprobe_trace_entry_head {
135 	struct trace_entry	ent;
136 	unsigned long		func;
137 	unsigned long		ret_ip;
138 };
139 
140 #define TRACE_BUF_SIZE		1024
141 
142 struct trace_array;
143 
144 /*
145  * The CPU trace array - it consists of thousands of trace entries
146  * plus some other descriptor data: (for example which task started
147  * the trace, etc.)
148  */
149 struct trace_array_cpu {
150 	atomic_t		disabled;
151 	void			*buffer_page;	/* ring buffer spare */
152 
153 	unsigned long		entries;
154 	unsigned long		saved_latency;
155 	unsigned long		critical_start;
156 	unsigned long		critical_end;
157 	unsigned long		critical_sequence;
158 	unsigned long		nice;
159 	unsigned long		policy;
160 	unsigned long		rt_priority;
161 	unsigned long		skipped_entries;
162 	u64			preempt_timestamp;
163 	pid_t			pid;
164 	kuid_t			uid;
165 	char			comm[TASK_COMM_LEN];
166 
167 #ifdef CONFIG_FUNCTION_TRACER
168 	int			ftrace_ignore_pid;
169 #endif
170 	bool			ignore_pid;
171 };
172 
173 struct tracer;
174 struct trace_option_dentry;
175 
176 struct array_buffer {
177 	struct trace_array		*tr;
178 	struct trace_buffer		*buffer;
179 	struct trace_array_cpu __percpu	*data;
180 	u64				time_start;
181 	int				cpu;
182 };
183 
184 #define TRACE_FLAGS_MAX_SIZE		32
185 
186 struct trace_options {
187 	struct tracer			*tracer;
188 	struct trace_option_dentry	*topts;
189 };
190 
191 struct trace_pid_list {
192 	int				pid_max;
193 	unsigned long			*pids;
194 };
195 
196 enum {
197 	TRACE_PIDS		= BIT(0),
198 	TRACE_NO_PIDS		= BIT(1),
199 };
200 
201 static inline bool pid_type_enabled(int type, struct trace_pid_list *pid_list,
202 				    struct trace_pid_list *no_pid_list)
203 {
204 	/* Return true if the pid list in type has pids */
205 	return ((type & TRACE_PIDS) && pid_list) ||
206 		((type & TRACE_NO_PIDS) && no_pid_list);
207 }
208 
209 static inline bool still_need_pid_events(int type, struct trace_pid_list *pid_list,
210 					 struct trace_pid_list *no_pid_list)
211 {
212 	/*
213 	 * Turning off what is in @type, return true if the "other"
214 	 * pid list, still has pids in it.
215 	 */
216 	return (!(type & TRACE_PIDS) && pid_list) ||
217 		(!(type & TRACE_NO_PIDS) && no_pid_list);
218 }
219 
220 typedef bool (*cond_update_fn_t)(struct trace_array *tr, void *cond_data);
221 
222 /**
223  * struct cond_snapshot - conditional snapshot data and callback
224  *
225  * The cond_snapshot structure encapsulates a callback function and
226  * data associated with the snapshot for a given tracing instance.
227  *
228  * When a snapshot is taken conditionally, by invoking
229  * tracing_snapshot_cond(tr, cond_data), the cond_data passed in is
230  * passed in turn to the cond_snapshot.update() function.  That data
231  * can be compared by the update() implementation with the cond_data
232  * contained within the struct cond_snapshot instance associated with
233  * the trace_array.  Because the tr->max_lock is held throughout the
234  * update() call, the update() function can directly retrieve the
235  * cond_snapshot and cond_data associated with the per-instance
236  * snapshot associated with the trace_array.
237  *
238  * The cond_snapshot.update() implementation can save data to be
239  * associated with the snapshot if it decides to, and returns 'true'
240  * in that case, or it returns 'false' if the conditional snapshot
241  * shouldn't be taken.
242  *
243  * The cond_snapshot instance is created and associated with the
244  * user-defined cond_data by tracing_cond_snapshot_enable().
245  * Likewise, the cond_snapshot instance is destroyed and is no longer
246  * associated with the trace instance by
247  * tracing_cond_snapshot_disable().
248  *
249  * The method below is required.
250  *
251  * @update: When a conditional snapshot is invoked, the update()
252  *	callback function is invoked with the tr->max_lock held.  The
253  *	update() implementation signals whether or not to actually
254  *	take the snapshot, by returning 'true' if so, 'false' if no
255  *	snapshot should be taken.  Because the max_lock is held for
256  *	the duration of update(), the implementation is safe to
257  *	directly retrieved and save any implementation data it needs
258  *	to in association with the snapshot.
259  */
260 struct cond_snapshot {
261 	void				*cond_data;
262 	cond_update_fn_t		update;
263 };
264 
265 /*
266  * struct trace_func_repeats - used to keep track of the consecutive
267  * (on the same CPU) calls of a single function.
268  */
269 struct trace_func_repeats {
270 	unsigned long	ip;
271 	unsigned long	parent_ip;
272 	unsigned long	count;
273 	u64		ts_last_call;
274 };
275 
276 /*
277  * The trace array - an array of per-CPU trace arrays. This is the
278  * highest level data structure that individual tracers deal with.
279  * They have on/off state as well:
280  */
281 struct trace_array {
282 	struct list_head	list;
283 	char			*name;
284 	struct array_buffer	array_buffer;
285 #ifdef CONFIG_TRACER_MAX_TRACE
286 	/*
287 	 * The max_buffer is used to snapshot the trace when a maximum
288 	 * latency is reached, or when the user initiates a snapshot.
289 	 * Some tracers will use this to store a maximum trace while
290 	 * it continues examining live traces.
291 	 *
292 	 * The buffers for the max_buffer are set up the same as the array_buffer
293 	 * When a snapshot is taken, the buffer of the max_buffer is swapped
294 	 * with the buffer of the array_buffer and the buffers are reset for
295 	 * the array_buffer so the tracing can continue.
296 	 */
297 	struct array_buffer	max_buffer;
298 	bool			allocated_snapshot;
299 #endif
300 #if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)
301 	unsigned long		max_latency;
302 #ifdef CONFIG_FSNOTIFY
303 	struct dentry		*d_max_latency;
304 	struct work_struct	fsnotify_work;
305 	struct irq_work		fsnotify_irqwork;
306 #endif
307 #endif
308 	struct trace_pid_list	__rcu *filtered_pids;
309 	struct trace_pid_list	__rcu *filtered_no_pids;
310 	/*
311 	 * max_lock is used to protect the swapping of buffers
312 	 * when taking a max snapshot. The buffers themselves are
313 	 * protected by per_cpu spinlocks. But the action of the swap
314 	 * needs its own lock.
315 	 *
316 	 * This is defined as a arch_spinlock_t in order to help
317 	 * with performance when lockdep debugging is enabled.
318 	 *
319 	 * It is also used in other places outside the update_max_tr
320 	 * so it needs to be defined outside of the
321 	 * CONFIG_TRACER_MAX_TRACE.
322 	 */
323 	arch_spinlock_t		max_lock;
324 	int			buffer_disabled;
325 #ifdef CONFIG_FTRACE_SYSCALLS
326 	int			sys_refcount_enter;
327 	int			sys_refcount_exit;
328 	struct trace_event_file __rcu *enter_syscall_files[NR_syscalls];
329 	struct trace_event_file __rcu *exit_syscall_files[NR_syscalls];
330 #endif
331 	int			stop_count;
332 	int			clock_id;
333 	int			nr_topts;
334 	bool			clear_trace;
335 	int			buffer_percent;
336 	unsigned int		n_err_log_entries;
337 	struct tracer		*current_trace;
338 	unsigned int		trace_flags;
339 	unsigned char		trace_flags_index[TRACE_FLAGS_MAX_SIZE];
340 	unsigned int		flags;
341 	raw_spinlock_t		start_lock;
342 	struct list_head	err_log;
343 	struct dentry		*dir;
344 	struct dentry		*options;
345 	struct dentry		*percpu_dir;
346 	struct dentry		*event_dir;
347 	struct trace_options	*topts;
348 	struct list_head	systems;
349 	struct list_head	events;
350 	struct trace_event_file *trace_marker_file;
351 	cpumask_var_t		tracing_cpumask; /* only trace on set CPUs */
352 	int			ref;
353 	int			trace_ref;
354 #ifdef CONFIG_FUNCTION_TRACER
355 	struct ftrace_ops	*ops;
356 	struct trace_pid_list	__rcu *function_pids;
357 	struct trace_pid_list	__rcu *function_no_pids;
358 #ifdef CONFIG_DYNAMIC_FTRACE
359 	/* All of these are protected by the ftrace_lock */
360 	struct list_head	func_probes;
361 	struct list_head	mod_trace;
362 	struct list_head	mod_notrace;
363 #endif
364 	/* function tracing enabled */
365 	int			function_enabled;
366 #endif
367 	int			no_filter_buffering_ref;
368 	struct list_head	hist_vars;
369 #ifdef CONFIG_TRACER_SNAPSHOT
370 	struct cond_snapshot	*cond_snapshot;
371 #endif
372 	struct trace_func_repeats	__percpu *last_func_repeats;
373 };
374 
375 enum {
376 	TRACE_ARRAY_FL_GLOBAL	= (1 << 0)
377 };
378 
379 extern struct list_head ftrace_trace_arrays;
380 
381 extern struct mutex trace_types_lock;
382 
383 extern int trace_array_get(struct trace_array *tr);
384 extern int tracing_check_open_get_tr(struct trace_array *tr);
385 extern struct trace_array *trace_array_find(const char *instance);
386 extern struct trace_array *trace_array_find_get(const char *instance);
387 
388 extern u64 tracing_event_time_stamp(struct trace_buffer *buffer, struct ring_buffer_event *rbe);
389 extern int tracing_set_filter_buffering(struct trace_array *tr, bool set);
390 extern int tracing_set_clock(struct trace_array *tr, const char *clockstr);
391 
392 extern bool trace_clock_in_ns(struct trace_array *tr);
393 
394 /*
395  * The global tracer (top) should be the first trace array added,
396  * but we check the flag anyway.
397  */
398 static inline struct trace_array *top_trace_array(void)
399 {
400 	struct trace_array *tr;
401 
402 	if (list_empty(&ftrace_trace_arrays))
403 		return NULL;
404 
405 	tr = list_entry(ftrace_trace_arrays.prev,
406 			typeof(*tr), list);
407 	WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
408 	return tr;
409 }
410 
411 #define FTRACE_CMP_TYPE(var, type) \
412 	__builtin_types_compatible_p(typeof(var), type *)
413 
414 #undef IF_ASSIGN
415 #define IF_ASSIGN(var, entry, etype, id)			\
416 	if (FTRACE_CMP_TYPE(var, etype)) {			\
417 		var = (typeof(var))(entry);			\
418 		WARN_ON(id != 0 && (entry)->type != id);	\
419 		break;						\
420 	}
421 
422 /* Will cause compile errors if type is not found. */
423 extern void __ftrace_bad_type(void);
424 
425 /*
426  * The trace_assign_type is a verifier that the entry type is
427  * the same as the type being assigned. To add new types simply
428  * add a line with the following format:
429  *
430  * IF_ASSIGN(var, ent, type, id);
431  *
432  *  Where "type" is the trace type that includes the trace_entry
433  *  as the "ent" item. And "id" is the trace identifier that is
434  *  used in the trace_type enum.
435  *
436  *  If the type can have more than one id, then use zero.
437  */
438 #define trace_assign_type(var, ent)					\
439 	do {								\
440 		IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);	\
441 		IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);	\
442 		IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);	\
443 		IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
444 		IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);	\
445 		IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT);	\
446 		IF_ASSIGN(var, ent, struct bputs_entry, TRACE_BPUTS);	\
447 		IF_ASSIGN(var, ent, struct hwlat_entry, TRACE_HWLAT);	\
448 		IF_ASSIGN(var, ent, struct raw_data_entry, TRACE_RAW_DATA);\
449 		IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,		\
450 			  TRACE_MMIO_RW);				\
451 		IF_ASSIGN(var, ent, struct trace_mmiotrace_map,		\
452 			  TRACE_MMIO_MAP);				\
453 		IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
454 		IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,	\
455 			  TRACE_GRAPH_ENT);		\
456 		IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,	\
457 			  TRACE_GRAPH_RET);		\
458 		IF_ASSIGN(var, ent, struct func_repeats_entry,		\
459 			  TRACE_FUNC_REPEATS);				\
460 		__ftrace_bad_type();					\
461 	} while (0)
462 
463 /*
464  * An option specific to a tracer. This is a boolean value.
465  * The bit is the bit index that sets its value on the
466  * flags value in struct tracer_flags.
467  */
468 struct tracer_opt {
469 	const char	*name; /* Will appear on the trace_options file */
470 	u32		bit; /* Mask assigned in val field in tracer_flags */
471 };
472 
473 /*
474  * The set of specific options for a tracer. Your tracer
475  * have to set the initial value of the flags val.
476  */
477 struct tracer_flags {
478 	u32			val;
479 	struct tracer_opt	*opts;
480 	struct tracer		*trace;
481 };
482 
483 /* Makes more easy to define a tracer opt */
484 #define TRACER_OPT(s, b)	.name = #s, .bit = b
485 
486 
487 struct trace_option_dentry {
488 	struct tracer_opt		*opt;
489 	struct tracer_flags		*flags;
490 	struct trace_array		*tr;
491 	struct dentry			*entry;
492 };
493 
494 /**
495  * struct tracer - a specific tracer and its callbacks to interact with tracefs
496  * @name: the name chosen to select it on the available_tracers file
497  * @init: called when one switches to this tracer (echo name > current_tracer)
498  * @reset: called when one switches to another tracer
499  * @start: called when tracing is unpaused (echo 1 > tracing_on)
500  * @stop: called when tracing is paused (echo 0 > tracing_on)
501  * @update_thresh: called when tracing_thresh is updated
502  * @open: called when the trace file is opened
503  * @pipe_open: called when the trace_pipe file is opened
504  * @close: called when the trace file is released
505  * @pipe_close: called when the trace_pipe file is released
506  * @read: override the default read callback on trace_pipe
507  * @splice_read: override the default splice_read callback on trace_pipe
508  * @selftest: selftest to run on boot (see trace_selftest.c)
509  * @print_headers: override the first lines that describe your columns
510  * @print_line: callback that prints a trace
511  * @set_flag: signals one of your private flags changed (trace_options file)
512  * @flags: your private flags
513  */
514 struct tracer {
515 	const char		*name;
516 	int			(*init)(struct trace_array *tr);
517 	void			(*reset)(struct trace_array *tr);
518 	void			(*start)(struct trace_array *tr);
519 	void			(*stop)(struct trace_array *tr);
520 	int			(*update_thresh)(struct trace_array *tr);
521 	void			(*open)(struct trace_iterator *iter);
522 	void			(*pipe_open)(struct trace_iterator *iter);
523 	void			(*close)(struct trace_iterator *iter);
524 	void			(*pipe_close)(struct trace_iterator *iter);
525 	ssize_t			(*read)(struct trace_iterator *iter,
526 					struct file *filp, char __user *ubuf,
527 					size_t cnt, loff_t *ppos);
528 	ssize_t			(*splice_read)(struct trace_iterator *iter,
529 					       struct file *filp,
530 					       loff_t *ppos,
531 					       struct pipe_inode_info *pipe,
532 					       size_t len,
533 					       unsigned int flags);
534 #ifdef CONFIG_FTRACE_STARTUP_TEST
535 	int			(*selftest)(struct tracer *trace,
536 					    struct trace_array *tr);
537 #endif
538 	void			(*print_header)(struct seq_file *m);
539 	enum print_line_t	(*print_line)(struct trace_iterator *iter);
540 	/* If you handled the flag setting, return 0 */
541 	int			(*set_flag)(struct trace_array *tr,
542 					    u32 old_flags, u32 bit, int set);
543 	/* Return 0 if OK with change, else return non-zero */
544 	int			(*flag_changed)(struct trace_array *tr,
545 						u32 mask, int set);
546 	struct tracer		*next;
547 	struct tracer_flags	*flags;
548 	int			enabled;
549 	bool			print_max;
550 	bool			allow_instances;
551 #ifdef CONFIG_TRACER_MAX_TRACE
552 	bool			use_max_tr;
553 #endif
554 	/* True if tracer cannot be enabled in kernel param */
555 	bool			noboot;
556 };
557 
558 static inline struct ring_buffer_iter *
559 trace_buffer_iter(struct trace_iterator *iter, int cpu)
560 {
561 	return iter->buffer_iter ? iter->buffer_iter[cpu] : NULL;
562 }
563 
564 int tracer_init(struct tracer *t, struct trace_array *tr);
565 int tracing_is_enabled(void);
566 void tracing_reset_online_cpus(struct array_buffer *buf);
567 void tracing_reset_current(int cpu);
568 void tracing_reset_all_online_cpus(void);
569 int tracing_open_generic(struct inode *inode, struct file *filp);
570 int tracing_open_generic_tr(struct inode *inode, struct file *filp);
571 bool tracing_is_disabled(void);
572 bool tracer_tracing_is_on(struct trace_array *tr);
573 void tracer_tracing_on(struct trace_array *tr);
574 void tracer_tracing_off(struct trace_array *tr);
575 struct dentry *trace_create_file(const char *name,
576 				 umode_t mode,
577 				 struct dentry *parent,
578 				 void *data,
579 				 const struct file_operations *fops);
580 
581 int tracing_init_dentry(void);
582 
583 struct ring_buffer_event;
584 
585 struct ring_buffer_event *
586 trace_buffer_lock_reserve(struct trace_buffer *buffer,
587 			  int type,
588 			  unsigned long len,
589 			  unsigned int trace_ctx);
590 
591 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
592 						struct trace_array_cpu *data);
593 
594 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
595 					  int *ent_cpu, u64 *ent_ts);
596 
597 void trace_buffer_unlock_commit_nostack(struct trace_buffer *buffer,
598 					struct ring_buffer_event *event);
599 
600 bool trace_is_tracepoint_string(const char *str);
601 const char *trace_event_format(struct trace_iterator *iter, const char *fmt);
602 void trace_check_vprintf(struct trace_iterator *iter, const char *fmt,
603 			 va_list ap);
604 
605 int trace_empty(struct trace_iterator *iter);
606 
607 void *trace_find_next_entry_inc(struct trace_iterator *iter);
608 
609 void trace_init_global_iter(struct trace_iterator *iter);
610 
611 void tracing_iter_reset(struct trace_iterator *iter, int cpu);
612 
613 unsigned long trace_total_entries_cpu(struct trace_array *tr, int cpu);
614 unsigned long trace_total_entries(struct trace_array *tr);
615 
616 void trace_function(struct trace_array *tr,
617 		    unsigned long ip,
618 		    unsigned long parent_ip,
619 		    unsigned int trace_ctx);
620 void trace_graph_function(struct trace_array *tr,
621 		    unsigned long ip,
622 		    unsigned long parent_ip,
623 		    unsigned int trace_ctx);
624 void trace_latency_header(struct seq_file *m);
625 void trace_default_header(struct seq_file *m);
626 void print_trace_header(struct seq_file *m, struct trace_iterator *iter);
627 
628 void trace_graph_return(struct ftrace_graph_ret *trace);
629 int trace_graph_entry(struct ftrace_graph_ent *trace);
630 void set_graph_array(struct trace_array *tr);
631 
632 void tracing_start_cmdline_record(void);
633 void tracing_stop_cmdline_record(void);
634 void tracing_start_tgid_record(void);
635 void tracing_stop_tgid_record(void);
636 
637 int register_tracer(struct tracer *type);
638 int is_tracing_stopped(void);
639 
640 loff_t tracing_lseek(struct file *file, loff_t offset, int whence);
641 
642 extern cpumask_var_t __read_mostly tracing_buffer_mask;
643 
644 #define for_each_tracing_cpu(cpu)	\
645 	for_each_cpu(cpu, tracing_buffer_mask)
646 
647 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
648 
649 extern unsigned long tracing_thresh;
650 
651 /* PID filtering */
652 
653 extern int pid_max;
654 
655 bool trace_find_filtered_pid(struct trace_pid_list *filtered_pids,
656 			     pid_t search_pid);
657 bool trace_ignore_this_task(struct trace_pid_list *filtered_pids,
658 			    struct trace_pid_list *filtered_no_pids,
659 			    struct task_struct *task);
660 void trace_filter_add_remove_task(struct trace_pid_list *pid_list,
661 				  struct task_struct *self,
662 				  struct task_struct *task);
663 void *trace_pid_next(struct trace_pid_list *pid_list, void *v, loff_t *pos);
664 void *trace_pid_start(struct trace_pid_list *pid_list, loff_t *pos);
665 int trace_pid_show(struct seq_file *m, void *v);
666 void trace_free_pid_list(struct trace_pid_list *pid_list);
667 int trace_pid_write(struct trace_pid_list *filtered_pids,
668 		    struct trace_pid_list **new_pid_list,
669 		    const char __user *ubuf, size_t cnt);
670 
671 #ifdef CONFIG_TRACER_MAX_TRACE
672 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu,
673 		   void *cond_data);
674 void update_max_tr_single(struct trace_array *tr,
675 			  struct task_struct *tsk, int cpu);
676 #endif /* CONFIG_TRACER_MAX_TRACE */
677 
678 #if (defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)) && \
679 	defined(CONFIG_FSNOTIFY)
680 
681 void latency_fsnotify(struct trace_array *tr);
682 
683 #else
684 
685 static inline void latency_fsnotify(struct trace_array *tr) { }
686 
687 #endif
688 
689 #ifdef CONFIG_STACKTRACE
690 void __trace_stack(struct trace_array *tr, unsigned int trace_ctx, int skip);
691 #else
692 static inline void __trace_stack(struct trace_array *tr, unsigned int trace_ctx,
693 				 int skip)
694 {
695 }
696 #endif /* CONFIG_STACKTRACE */
697 
698 void trace_last_func_repeats(struct trace_array *tr,
699 			     struct trace_func_repeats *last_info,
700 			     unsigned int trace_ctx);
701 
702 extern u64 ftrace_now(int cpu);
703 
704 extern void trace_find_cmdline(int pid, char comm[]);
705 extern int trace_find_tgid(int pid);
706 extern void trace_event_follow_fork(struct trace_array *tr, bool enable);
707 
708 #ifdef CONFIG_DYNAMIC_FTRACE
709 extern unsigned long ftrace_update_tot_cnt;
710 extern unsigned long ftrace_number_of_pages;
711 extern unsigned long ftrace_number_of_groups;
712 void ftrace_init_trace_array(struct trace_array *tr);
713 #else
714 static inline void ftrace_init_trace_array(struct trace_array *tr) { }
715 #endif
716 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
717 extern int DYN_FTRACE_TEST_NAME(void);
718 #define DYN_FTRACE_TEST_NAME2 trace_selftest_dynamic_test_func2
719 extern int DYN_FTRACE_TEST_NAME2(void);
720 
721 extern bool ring_buffer_expanded;
722 extern bool tracing_selftest_disabled;
723 
724 #ifdef CONFIG_FTRACE_STARTUP_TEST
725 extern void __init disable_tracing_selftest(const char *reason);
726 
727 extern int trace_selftest_startup_function(struct tracer *trace,
728 					   struct trace_array *tr);
729 extern int trace_selftest_startup_function_graph(struct tracer *trace,
730 						 struct trace_array *tr);
731 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
732 					  struct trace_array *tr);
733 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
734 					     struct trace_array *tr);
735 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
736 						 struct trace_array *tr);
737 extern int trace_selftest_startup_wakeup(struct tracer *trace,
738 					 struct trace_array *tr);
739 extern int trace_selftest_startup_nop(struct tracer *trace,
740 					 struct trace_array *tr);
741 extern int trace_selftest_startup_branch(struct tracer *trace,
742 					 struct trace_array *tr);
743 /*
744  * Tracer data references selftest functions that only occur
745  * on boot up. These can be __init functions. Thus, when selftests
746  * are enabled, then the tracers need to reference __init functions.
747  */
748 #define __tracer_data		__refdata
749 #else
750 static inline void __init disable_tracing_selftest(const char *reason)
751 {
752 }
753 /* Tracers are seldom changed. Optimize when selftests are disabled. */
754 #define __tracer_data		__read_mostly
755 #endif /* CONFIG_FTRACE_STARTUP_TEST */
756 
757 extern void *head_page(struct trace_array_cpu *data);
758 extern unsigned long long ns2usecs(u64 nsec);
759 extern int
760 trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
761 extern int
762 trace_vprintk(unsigned long ip, const char *fmt, va_list args);
763 extern int
764 trace_array_vprintk(struct trace_array *tr,
765 		    unsigned long ip, const char *fmt, va_list args);
766 int trace_array_printk_buf(struct trace_buffer *buffer,
767 			   unsigned long ip, const char *fmt, ...);
768 void trace_printk_seq(struct trace_seq *s);
769 enum print_line_t print_trace_line(struct trace_iterator *iter);
770 
771 extern char trace_find_mark(unsigned long long duration);
772 
773 struct ftrace_hash;
774 
775 struct ftrace_mod_load {
776 	struct list_head	list;
777 	char			*func;
778 	char			*module;
779 	int			 enable;
780 };
781 
782 enum {
783 	FTRACE_HASH_FL_MOD	= (1 << 0),
784 };
785 
786 struct ftrace_hash {
787 	unsigned long		size_bits;
788 	struct hlist_head	*buckets;
789 	unsigned long		count;
790 	unsigned long		flags;
791 	struct rcu_head		rcu;
792 };
793 
794 struct ftrace_func_entry *
795 ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip);
796 
797 static __always_inline bool ftrace_hash_empty(struct ftrace_hash *hash)
798 {
799 	return !hash || !(hash->count || (hash->flags & FTRACE_HASH_FL_MOD));
800 }
801 
802 /* Standard output formatting function used for function return traces */
803 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
804 
805 /* Flag options */
806 #define TRACE_GRAPH_PRINT_OVERRUN       0x1
807 #define TRACE_GRAPH_PRINT_CPU           0x2
808 #define TRACE_GRAPH_PRINT_OVERHEAD      0x4
809 #define TRACE_GRAPH_PRINT_PROC          0x8
810 #define TRACE_GRAPH_PRINT_DURATION      0x10
811 #define TRACE_GRAPH_PRINT_ABS_TIME      0x20
812 #define TRACE_GRAPH_PRINT_REL_TIME      0x40
813 #define TRACE_GRAPH_PRINT_IRQS          0x80
814 #define TRACE_GRAPH_PRINT_TAIL          0x100
815 #define TRACE_GRAPH_SLEEP_TIME          0x200
816 #define TRACE_GRAPH_GRAPH_TIME          0x400
817 #define TRACE_GRAPH_PRINT_FILL_SHIFT	28
818 #define TRACE_GRAPH_PRINT_FILL_MASK	(0x3 << TRACE_GRAPH_PRINT_FILL_SHIFT)
819 
820 extern void ftrace_graph_sleep_time_control(bool enable);
821 
822 #ifdef CONFIG_FUNCTION_PROFILER
823 extern void ftrace_graph_graph_time_control(bool enable);
824 #else
825 static inline void ftrace_graph_graph_time_control(bool enable) { }
826 #endif
827 
828 extern enum print_line_t
829 print_graph_function_flags(struct trace_iterator *iter, u32 flags);
830 extern void print_graph_headers_flags(struct seq_file *s, u32 flags);
831 extern void
832 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
833 extern void graph_trace_open(struct trace_iterator *iter);
834 extern void graph_trace_close(struct trace_iterator *iter);
835 extern int __trace_graph_entry(struct trace_array *tr,
836 			       struct ftrace_graph_ent *trace,
837 			       unsigned int trace_ctx);
838 extern void __trace_graph_return(struct trace_array *tr,
839 				 struct ftrace_graph_ret *trace,
840 				 unsigned int trace_ctx);
841 
842 #ifdef CONFIG_DYNAMIC_FTRACE
843 extern struct ftrace_hash __rcu *ftrace_graph_hash;
844 extern struct ftrace_hash __rcu *ftrace_graph_notrace_hash;
845 
846 static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace)
847 {
848 	unsigned long addr = trace->func;
849 	int ret = 0;
850 	struct ftrace_hash *hash;
851 
852 	preempt_disable_notrace();
853 
854 	/*
855 	 * Have to open code "rcu_dereference_sched()" because the
856 	 * function graph tracer can be called when RCU is not
857 	 * "watching".
858 	 * Protected with schedule_on_each_cpu(ftrace_sync)
859 	 */
860 	hash = rcu_dereference_protected(ftrace_graph_hash, !preemptible());
861 
862 	if (ftrace_hash_empty(hash)) {
863 		ret = 1;
864 		goto out;
865 	}
866 
867 	if (ftrace_lookup_ip(hash, addr)) {
868 
869 		/*
870 		 * This needs to be cleared on the return functions
871 		 * when the depth is zero.
872 		 */
873 		trace_recursion_set(TRACE_GRAPH_BIT);
874 		trace_recursion_set_depth(trace->depth);
875 
876 		/*
877 		 * If no irqs are to be traced, but a set_graph_function
878 		 * is set, and called by an interrupt handler, we still
879 		 * want to trace it.
880 		 */
881 		if (in_irq())
882 			trace_recursion_set(TRACE_IRQ_BIT);
883 		else
884 			trace_recursion_clear(TRACE_IRQ_BIT);
885 		ret = 1;
886 	}
887 
888 out:
889 	preempt_enable_notrace();
890 	return ret;
891 }
892 
893 static inline void ftrace_graph_addr_finish(struct ftrace_graph_ret *trace)
894 {
895 	if (trace_recursion_test(TRACE_GRAPH_BIT) &&
896 	    trace->depth == trace_recursion_depth())
897 		trace_recursion_clear(TRACE_GRAPH_BIT);
898 }
899 
900 static inline int ftrace_graph_notrace_addr(unsigned long addr)
901 {
902 	int ret = 0;
903 	struct ftrace_hash *notrace_hash;
904 
905 	preempt_disable_notrace();
906 
907 	/*
908 	 * Have to open code "rcu_dereference_sched()" because the
909 	 * function graph tracer can be called when RCU is not
910 	 * "watching".
911 	 * Protected with schedule_on_each_cpu(ftrace_sync)
912 	 */
913 	notrace_hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
914 						 !preemptible());
915 
916 	if (ftrace_lookup_ip(notrace_hash, addr))
917 		ret = 1;
918 
919 	preempt_enable_notrace();
920 	return ret;
921 }
922 #else
923 static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace)
924 {
925 	return 1;
926 }
927 
928 static inline int ftrace_graph_notrace_addr(unsigned long addr)
929 {
930 	return 0;
931 }
932 static inline void ftrace_graph_addr_finish(struct ftrace_graph_ret *trace)
933 { }
934 #endif /* CONFIG_DYNAMIC_FTRACE */
935 
936 extern unsigned int fgraph_max_depth;
937 
938 static inline bool ftrace_graph_ignore_func(struct ftrace_graph_ent *trace)
939 {
940 	/* trace it when it is-nested-in or is a function enabled. */
941 	return !(trace_recursion_test(TRACE_GRAPH_BIT) ||
942 		 ftrace_graph_addr(trace)) ||
943 		(trace->depth < 0) ||
944 		(fgraph_max_depth && trace->depth >= fgraph_max_depth);
945 }
946 
947 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
948 static inline enum print_line_t
949 print_graph_function_flags(struct trace_iterator *iter, u32 flags)
950 {
951 	return TRACE_TYPE_UNHANDLED;
952 }
953 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
954 
955 extern struct list_head ftrace_pids;
956 
957 #ifdef CONFIG_FUNCTION_TRACER
958 
959 #define FTRACE_PID_IGNORE	-1
960 #define FTRACE_PID_TRACE	-2
961 
962 struct ftrace_func_command {
963 	struct list_head	list;
964 	char			*name;
965 	int			(*func)(struct trace_array *tr,
966 					struct ftrace_hash *hash,
967 					char *func, char *cmd,
968 					char *params, int enable);
969 };
970 extern bool ftrace_filter_param __initdata;
971 static inline int ftrace_trace_task(struct trace_array *tr)
972 {
973 	return this_cpu_read(tr->array_buffer.data->ftrace_ignore_pid) !=
974 		FTRACE_PID_IGNORE;
975 }
976 extern int ftrace_is_dead(void);
977 int ftrace_create_function_files(struct trace_array *tr,
978 				 struct dentry *parent);
979 void ftrace_destroy_function_files(struct trace_array *tr);
980 int ftrace_allocate_ftrace_ops(struct trace_array *tr);
981 void ftrace_free_ftrace_ops(struct trace_array *tr);
982 void ftrace_init_global_array_ops(struct trace_array *tr);
983 void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func);
984 void ftrace_reset_array_ops(struct trace_array *tr);
985 void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer);
986 void ftrace_init_tracefs_toplevel(struct trace_array *tr,
987 				  struct dentry *d_tracer);
988 void ftrace_clear_pids(struct trace_array *tr);
989 int init_function_trace(void);
990 void ftrace_pid_follow_fork(struct trace_array *tr, bool enable);
991 #else
992 static inline int ftrace_trace_task(struct trace_array *tr)
993 {
994 	return 1;
995 }
996 static inline int ftrace_is_dead(void) { return 0; }
997 static inline int
998 ftrace_create_function_files(struct trace_array *tr,
999 			     struct dentry *parent)
1000 {
1001 	return 0;
1002 }
1003 static inline int ftrace_allocate_ftrace_ops(struct trace_array *tr)
1004 {
1005 	return 0;
1006 }
1007 static inline void ftrace_free_ftrace_ops(struct trace_array *tr) { }
1008 static inline void ftrace_destroy_function_files(struct trace_array *tr) { }
1009 static inline __init void
1010 ftrace_init_global_array_ops(struct trace_array *tr) { }
1011 static inline void ftrace_reset_array_ops(struct trace_array *tr) { }
1012 static inline void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d) { }
1013 static inline void ftrace_init_tracefs_toplevel(struct trace_array *tr, struct dentry *d) { }
1014 static inline void ftrace_clear_pids(struct trace_array *tr) { }
1015 static inline int init_function_trace(void) { return 0; }
1016 static inline void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) { }
1017 /* ftace_func_t type is not defined, use macro instead of static inline */
1018 #define ftrace_init_array_ops(tr, func) do { } while (0)
1019 #endif /* CONFIG_FUNCTION_TRACER */
1020 
1021 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
1022 
1023 struct ftrace_probe_ops {
1024 	void			(*func)(unsigned long ip,
1025 					unsigned long parent_ip,
1026 					struct trace_array *tr,
1027 					struct ftrace_probe_ops *ops,
1028 					void *data);
1029 	int			(*init)(struct ftrace_probe_ops *ops,
1030 					struct trace_array *tr,
1031 					unsigned long ip, void *init_data,
1032 					void **data);
1033 	void			(*free)(struct ftrace_probe_ops *ops,
1034 					struct trace_array *tr,
1035 					unsigned long ip, void *data);
1036 	int			(*print)(struct seq_file *m,
1037 					 unsigned long ip,
1038 					 struct ftrace_probe_ops *ops,
1039 					 void *data);
1040 };
1041 
1042 struct ftrace_func_mapper;
1043 typedef int (*ftrace_mapper_func)(void *data);
1044 
1045 struct ftrace_func_mapper *allocate_ftrace_func_mapper(void);
1046 void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
1047 					   unsigned long ip);
1048 int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
1049 			       unsigned long ip, void *data);
1050 void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
1051 				   unsigned long ip);
1052 void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
1053 			     ftrace_mapper_func free_func);
1054 
1055 extern int
1056 register_ftrace_function_probe(char *glob, struct trace_array *tr,
1057 			       struct ftrace_probe_ops *ops, void *data);
1058 extern int
1059 unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
1060 				      struct ftrace_probe_ops *ops);
1061 extern void clear_ftrace_function_probes(struct trace_array *tr);
1062 
1063 int register_ftrace_command(struct ftrace_func_command *cmd);
1064 int unregister_ftrace_command(struct ftrace_func_command *cmd);
1065 
1066 void ftrace_create_filter_files(struct ftrace_ops *ops,
1067 				struct dentry *parent);
1068 void ftrace_destroy_filter_files(struct ftrace_ops *ops);
1069 
1070 extern int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
1071 			     int len, int reset);
1072 extern int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
1073 			      int len, int reset);
1074 #else
1075 struct ftrace_func_command;
1076 
1077 static inline __init int register_ftrace_command(struct ftrace_func_command *cmd)
1078 {
1079 	return -EINVAL;
1080 }
1081 static inline __init int unregister_ftrace_command(char *cmd_name)
1082 {
1083 	return -EINVAL;
1084 }
1085 static inline void clear_ftrace_function_probes(struct trace_array *tr)
1086 {
1087 }
1088 
1089 /*
1090  * The ops parameter passed in is usually undefined.
1091  * This must be a macro.
1092  */
1093 #define ftrace_create_filter_files(ops, parent) do { } while (0)
1094 #define ftrace_destroy_filter_files(ops) do { } while (0)
1095 #endif /* CONFIG_FUNCTION_TRACER && CONFIG_DYNAMIC_FTRACE */
1096 
1097 bool ftrace_event_is_function(struct trace_event_call *call);
1098 
1099 /*
1100  * struct trace_parser - servers for reading the user input separated by spaces
1101  * @cont: set if the input is not complete - no final space char was found
1102  * @buffer: holds the parsed user input
1103  * @idx: user input length
1104  * @size: buffer size
1105  */
1106 struct trace_parser {
1107 	bool		cont;
1108 	char		*buffer;
1109 	unsigned	idx;
1110 	unsigned	size;
1111 };
1112 
1113 static inline bool trace_parser_loaded(struct trace_parser *parser)
1114 {
1115 	return (parser->idx != 0);
1116 }
1117 
1118 static inline bool trace_parser_cont(struct trace_parser *parser)
1119 {
1120 	return parser->cont;
1121 }
1122 
1123 static inline void trace_parser_clear(struct trace_parser *parser)
1124 {
1125 	parser->cont = false;
1126 	parser->idx = 0;
1127 }
1128 
1129 extern int trace_parser_get_init(struct trace_parser *parser, int size);
1130 extern void trace_parser_put(struct trace_parser *parser);
1131 extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
1132 	size_t cnt, loff_t *ppos);
1133 
1134 /*
1135  * Only create function graph options if function graph is configured.
1136  */
1137 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1138 # define FGRAPH_FLAGS						\
1139 		C(DISPLAY_GRAPH,	"display-graph"),
1140 #else
1141 # define FGRAPH_FLAGS
1142 #endif
1143 
1144 #ifdef CONFIG_BRANCH_TRACER
1145 # define BRANCH_FLAGS					\
1146 		C(BRANCH,		"branch"),
1147 #else
1148 # define BRANCH_FLAGS
1149 #endif
1150 
1151 #ifdef CONFIG_FUNCTION_TRACER
1152 # define FUNCTION_FLAGS						\
1153 		C(FUNCTION,		"function-trace"),	\
1154 		C(FUNC_FORK,		"function-fork"),
1155 # define FUNCTION_DEFAULT_FLAGS		TRACE_ITER_FUNCTION
1156 #else
1157 # define FUNCTION_FLAGS
1158 # define FUNCTION_DEFAULT_FLAGS		0UL
1159 # define TRACE_ITER_FUNC_FORK		0UL
1160 #endif
1161 
1162 #ifdef CONFIG_STACKTRACE
1163 # define STACK_FLAGS				\
1164 		C(STACKTRACE,		"stacktrace"),
1165 #else
1166 # define STACK_FLAGS
1167 #endif
1168 
1169 /*
1170  * trace_iterator_flags is an enumeration that defines bit
1171  * positions into trace_flags that controls the output.
1172  *
1173  * NOTE: These bits must match the trace_options array in
1174  *       trace.c (this macro guarantees it).
1175  */
1176 #define TRACE_FLAGS						\
1177 		C(PRINT_PARENT,		"print-parent"),	\
1178 		C(SYM_OFFSET,		"sym-offset"),		\
1179 		C(SYM_ADDR,		"sym-addr"),		\
1180 		C(VERBOSE,		"verbose"),		\
1181 		C(RAW,			"raw"),			\
1182 		C(HEX,			"hex"),			\
1183 		C(BIN,			"bin"),			\
1184 		C(BLOCK,		"block"),		\
1185 		C(PRINTK,		"trace_printk"),	\
1186 		C(ANNOTATE,		"annotate"),		\
1187 		C(USERSTACKTRACE,	"userstacktrace"),	\
1188 		C(SYM_USEROBJ,		"sym-userobj"),		\
1189 		C(PRINTK_MSGONLY,	"printk-msg-only"),	\
1190 		C(CONTEXT_INFO,		"context-info"),   /* Print pid/cpu/time */ \
1191 		C(LATENCY_FMT,		"latency-format"),	\
1192 		C(RECORD_CMD,		"record-cmd"),		\
1193 		C(RECORD_TGID,		"record-tgid"),		\
1194 		C(OVERWRITE,		"overwrite"),		\
1195 		C(STOP_ON_FREE,		"disable_on_free"),	\
1196 		C(IRQ_INFO,		"irq-info"),		\
1197 		C(MARKERS,		"markers"),		\
1198 		C(EVENT_FORK,		"event-fork"),		\
1199 		C(PAUSE_ON_TRACE,	"pause-on-trace"),	\
1200 		C(HASH_PTR,		"hash-ptr"),	/* Print hashed pointer */ \
1201 		FUNCTION_FLAGS					\
1202 		FGRAPH_FLAGS					\
1203 		STACK_FLAGS					\
1204 		BRANCH_FLAGS
1205 
1206 /*
1207  * By defining C, we can make TRACE_FLAGS a list of bit names
1208  * that will define the bits for the flag masks.
1209  */
1210 #undef C
1211 #define C(a, b) TRACE_ITER_##a##_BIT
1212 
1213 enum trace_iterator_bits {
1214 	TRACE_FLAGS
1215 	/* Make sure we don't go more than we have bits for */
1216 	TRACE_ITER_LAST_BIT
1217 };
1218 
1219 /*
1220  * By redefining C, we can make TRACE_FLAGS a list of masks that
1221  * use the bits as defined above.
1222  */
1223 #undef C
1224 #define C(a, b) TRACE_ITER_##a = (1 << TRACE_ITER_##a##_BIT)
1225 
1226 enum trace_iterator_flags { TRACE_FLAGS };
1227 
1228 /*
1229  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
1230  * control the output of kernel symbols.
1231  */
1232 #define TRACE_ITER_SYM_MASK \
1233 	(TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
1234 
1235 extern struct tracer nop_trace;
1236 
1237 #ifdef CONFIG_BRANCH_TRACER
1238 extern int enable_branch_tracing(struct trace_array *tr);
1239 extern void disable_branch_tracing(void);
1240 static inline int trace_branch_enable(struct trace_array *tr)
1241 {
1242 	if (tr->trace_flags & TRACE_ITER_BRANCH)
1243 		return enable_branch_tracing(tr);
1244 	return 0;
1245 }
1246 static inline void trace_branch_disable(void)
1247 {
1248 	/* due to races, always disable */
1249 	disable_branch_tracing();
1250 }
1251 #else
1252 static inline int trace_branch_enable(struct trace_array *tr)
1253 {
1254 	return 0;
1255 }
1256 static inline void trace_branch_disable(void)
1257 {
1258 }
1259 #endif /* CONFIG_BRANCH_TRACER */
1260 
1261 /* set ring buffers to default size if not already done so */
1262 int tracing_update_buffers(void);
1263 
1264 struct ftrace_event_field {
1265 	struct list_head	link;
1266 	const char		*name;
1267 	const char		*type;
1268 	int			filter_type;
1269 	int			offset;
1270 	int			size;
1271 	int			is_signed;
1272 };
1273 
1274 struct prog_entry;
1275 
1276 struct event_filter {
1277 	struct prog_entry __rcu	*prog;
1278 	char			*filter_string;
1279 };
1280 
1281 struct event_subsystem {
1282 	struct list_head	list;
1283 	const char		*name;
1284 	struct event_filter	*filter;
1285 	int			ref_count;
1286 };
1287 
1288 struct trace_subsystem_dir {
1289 	struct list_head		list;
1290 	struct event_subsystem		*subsystem;
1291 	struct trace_array		*tr;
1292 	struct dentry			*entry;
1293 	int				ref_count;
1294 	int				nr_events;
1295 };
1296 
1297 extern int call_filter_check_discard(struct trace_event_call *call, void *rec,
1298 				     struct trace_buffer *buffer,
1299 				     struct ring_buffer_event *event);
1300 
1301 void trace_buffer_unlock_commit_regs(struct trace_array *tr,
1302 				     struct trace_buffer *buffer,
1303 				     struct ring_buffer_event *event,
1304 				     unsigned int trcace_ctx,
1305 				     struct pt_regs *regs);
1306 
1307 static inline void trace_buffer_unlock_commit(struct trace_array *tr,
1308 					      struct trace_buffer *buffer,
1309 					      struct ring_buffer_event *event,
1310 					      unsigned int trace_ctx)
1311 {
1312 	trace_buffer_unlock_commit_regs(tr, buffer, event, trace_ctx, NULL);
1313 }
1314 
1315 DECLARE_PER_CPU(struct ring_buffer_event *, trace_buffered_event);
1316 DECLARE_PER_CPU(int, trace_buffered_event_cnt);
1317 void trace_buffered_event_disable(void);
1318 void trace_buffered_event_enable(void);
1319 
1320 static inline void
1321 __trace_event_discard_commit(struct trace_buffer *buffer,
1322 			     struct ring_buffer_event *event)
1323 {
1324 	if (this_cpu_read(trace_buffered_event) == event) {
1325 		/* Simply release the temp buffer */
1326 		this_cpu_dec(trace_buffered_event_cnt);
1327 		return;
1328 	}
1329 	ring_buffer_discard_commit(buffer, event);
1330 }
1331 
1332 /*
1333  * Helper function for event_trigger_unlock_commit{_regs}().
1334  * If there are event triggers attached to this event that requires
1335  * filtering against its fields, then they will be called as the
1336  * entry already holds the field information of the current event.
1337  *
1338  * It also checks if the event should be discarded or not.
1339  * It is to be discarded if the event is soft disabled and the
1340  * event was only recorded to process triggers, or if the event
1341  * filter is active and this event did not match the filters.
1342  *
1343  * Returns true if the event is discarded, false otherwise.
1344  */
1345 static inline bool
1346 __event_trigger_test_discard(struct trace_event_file *file,
1347 			     struct trace_buffer *buffer,
1348 			     struct ring_buffer_event *event,
1349 			     void *entry,
1350 			     enum event_trigger_type *tt)
1351 {
1352 	unsigned long eflags = file->flags;
1353 
1354 	if (eflags & EVENT_FILE_FL_TRIGGER_COND)
1355 		*tt = event_triggers_call(file, buffer, entry, event);
1356 
1357 	if (test_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags) ||
1358 	    (unlikely(file->flags & EVENT_FILE_FL_FILTERED) &&
1359 	     !filter_match_preds(file->filter, entry))) {
1360 		__trace_event_discard_commit(buffer, event);
1361 		return true;
1362 	}
1363 
1364 	return false;
1365 }
1366 
1367 /**
1368  * event_trigger_unlock_commit - handle triggers and finish event commit
1369  * @file: The file pointer associated with the event
1370  * @buffer: The ring buffer that the event is being written to
1371  * @event: The event meta data in the ring buffer
1372  * @entry: The event itself
1373  * @trace_ctx: The tracing context flags.
1374  *
1375  * This is a helper function to handle triggers that require data
1376  * from the event itself. It also tests the event against filters and
1377  * if the event is soft disabled and should be discarded.
1378  */
1379 static inline void
1380 event_trigger_unlock_commit(struct trace_event_file *file,
1381 			    struct trace_buffer *buffer,
1382 			    struct ring_buffer_event *event,
1383 			    void *entry, unsigned int trace_ctx)
1384 {
1385 	enum event_trigger_type tt = ETT_NONE;
1386 
1387 	if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1388 		trace_buffer_unlock_commit(file->tr, buffer, event, trace_ctx);
1389 
1390 	if (tt)
1391 		event_triggers_post_call(file, tt);
1392 }
1393 
1394 /**
1395  * event_trigger_unlock_commit_regs - handle triggers and finish event commit
1396  * @file: The file pointer associated with the event
1397  * @buffer: The ring buffer that the event is being written to
1398  * @event: The event meta data in the ring buffer
1399  * @entry: The event itself
1400  * @trace_ctx: The tracing context flags.
1401  *
1402  * This is a helper function to handle triggers that require data
1403  * from the event itself. It also tests the event against filters and
1404  * if the event is soft disabled and should be discarded.
1405  *
1406  * Same as event_trigger_unlock_commit() but calls
1407  * trace_buffer_unlock_commit_regs() instead of trace_buffer_unlock_commit().
1408  */
1409 static inline void
1410 event_trigger_unlock_commit_regs(struct trace_event_file *file,
1411 				 struct trace_buffer *buffer,
1412 				 struct ring_buffer_event *event,
1413 				 void *entry, unsigned int trace_ctx,
1414 				 struct pt_regs *regs)
1415 {
1416 	enum event_trigger_type tt = ETT_NONE;
1417 
1418 	if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1419 		trace_buffer_unlock_commit_regs(file->tr, buffer, event,
1420 						trace_ctx, regs);
1421 
1422 	if (tt)
1423 		event_triggers_post_call(file, tt);
1424 }
1425 
1426 #define FILTER_PRED_INVALID	((unsigned short)-1)
1427 #define FILTER_PRED_IS_RIGHT	(1 << 15)
1428 #define FILTER_PRED_FOLD	(1 << 15)
1429 
1430 /*
1431  * The max preds is the size of unsigned short with
1432  * two flags at the MSBs. One bit is used for both the IS_RIGHT
1433  * and FOLD flags. The other is reserved.
1434  *
1435  * 2^14 preds is way more than enough.
1436  */
1437 #define MAX_FILTER_PRED		16384
1438 
1439 struct filter_pred;
1440 struct regex;
1441 
1442 typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event);
1443 
1444 typedef int (*regex_match_func)(char *str, struct regex *r, int len);
1445 
1446 enum regex_type {
1447 	MATCH_FULL = 0,
1448 	MATCH_FRONT_ONLY,
1449 	MATCH_MIDDLE_ONLY,
1450 	MATCH_END_ONLY,
1451 	MATCH_GLOB,
1452 	MATCH_INDEX,
1453 };
1454 
1455 struct regex {
1456 	char			pattern[MAX_FILTER_STR_VAL];
1457 	int			len;
1458 	int			field_len;
1459 	regex_match_func	match;
1460 };
1461 
1462 struct filter_pred {
1463 	filter_pred_fn_t 	fn;
1464 	u64 			val;
1465 	struct regex		regex;
1466 	unsigned short		*ops;
1467 	struct ftrace_event_field *field;
1468 	int 			offset;
1469 	int			not;
1470 	int 			op;
1471 };
1472 
1473 static inline bool is_string_field(struct ftrace_event_field *field)
1474 {
1475 	return field->filter_type == FILTER_DYN_STRING ||
1476 	       field->filter_type == FILTER_STATIC_STRING ||
1477 	       field->filter_type == FILTER_PTR_STRING ||
1478 	       field->filter_type == FILTER_COMM;
1479 }
1480 
1481 static inline bool is_function_field(struct ftrace_event_field *field)
1482 {
1483 	return field->filter_type == FILTER_TRACE_FN;
1484 }
1485 
1486 extern enum regex_type
1487 filter_parse_regex(char *buff, int len, char **search, int *not);
1488 extern void print_event_filter(struct trace_event_file *file,
1489 			       struct trace_seq *s);
1490 extern int apply_event_filter(struct trace_event_file *file,
1491 			      char *filter_string);
1492 extern int apply_subsystem_event_filter(struct trace_subsystem_dir *dir,
1493 					char *filter_string);
1494 extern void print_subsystem_event_filter(struct event_subsystem *system,
1495 					 struct trace_seq *s);
1496 extern int filter_assign_type(const char *type);
1497 extern int create_event_filter(struct trace_array *tr,
1498 			       struct trace_event_call *call,
1499 			       char *filter_str, bool set_str,
1500 			       struct event_filter **filterp);
1501 extern void free_event_filter(struct event_filter *filter);
1502 
1503 struct ftrace_event_field *
1504 trace_find_event_field(struct trace_event_call *call, char *name);
1505 
1506 extern void trace_event_enable_cmd_record(bool enable);
1507 extern void trace_event_enable_tgid_record(bool enable);
1508 
1509 extern int event_trace_init(void);
1510 extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
1511 extern int event_trace_del_tracer(struct trace_array *tr);
1512 extern void __trace_early_add_events(struct trace_array *tr);
1513 
1514 extern struct trace_event_file *__find_event_file(struct trace_array *tr,
1515 						  const char *system,
1516 						  const char *event);
1517 extern struct trace_event_file *find_event_file(struct trace_array *tr,
1518 						const char *system,
1519 						const char *event);
1520 
1521 static inline void *event_file_data(struct file *filp)
1522 {
1523 	return READ_ONCE(file_inode(filp)->i_private);
1524 }
1525 
1526 extern struct mutex event_mutex;
1527 extern struct list_head ftrace_events;
1528 
1529 extern const struct file_operations event_trigger_fops;
1530 extern const struct file_operations event_hist_fops;
1531 extern const struct file_operations event_hist_debug_fops;
1532 extern const struct file_operations event_inject_fops;
1533 
1534 #ifdef CONFIG_HIST_TRIGGERS
1535 extern int register_trigger_hist_cmd(void);
1536 extern int register_trigger_hist_enable_disable_cmds(void);
1537 #else
1538 static inline int register_trigger_hist_cmd(void) { return 0; }
1539 static inline int register_trigger_hist_enable_disable_cmds(void) { return 0; }
1540 #endif
1541 
1542 extern int register_trigger_cmds(void);
1543 extern void clear_event_triggers(struct trace_array *tr);
1544 
1545 struct event_trigger_data {
1546 	unsigned long			count;
1547 	int				ref;
1548 	struct event_trigger_ops	*ops;
1549 	struct event_command		*cmd_ops;
1550 	struct event_filter __rcu	*filter;
1551 	char				*filter_str;
1552 	void				*private_data;
1553 	bool				paused;
1554 	bool				paused_tmp;
1555 	struct list_head		list;
1556 	char				*name;
1557 	struct list_head		named_list;
1558 	struct event_trigger_data	*named_data;
1559 };
1560 
1561 /* Avoid typos */
1562 #define ENABLE_EVENT_STR	"enable_event"
1563 #define DISABLE_EVENT_STR	"disable_event"
1564 #define ENABLE_HIST_STR		"enable_hist"
1565 #define DISABLE_HIST_STR	"disable_hist"
1566 
1567 struct enable_trigger_data {
1568 	struct trace_event_file		*file;
1569 	bool				enable;
1570 	bool				hist;
1571 };
1572 
1573 extern int event_enable_trigger_print(struct seq_file *m,
1574 				      struct event_trigger_ops *ops,
1575 				      struct event_trigger_data *data);
1576 extern void event_enable_trigger_free(struct event_trigger_ops *ops,
1577 				      struct event_trigger_data *data);
1578 extern int event_enable_trigger_func(struct event_command *cmd_ops,
1579 				     struct trace_event_file *file,
1580 				     char *glob, char *cmd, char *param);
1581 extern int event_enable_register_trigger(char *glob,
1582 					 struct event_trigger_ops *ops,
1583 					 struct event_trigger_data *data,
1584 					 struct trace_event_file *file);
1585 extern void event_enable_unregister_trigger(char *glob,
1586 					    struct event_trigger_ops *ops,
1587 					    struct event_trigger_data *test,
1588 					    struct trace_event_file *file);
1589 extern void trigger_data_free(struct event_trigger_data *data);
1590 extern int event_trigger_init(struct event_trigger_ops *ops,
1591 			      struct event_trigger_data *data);
1592 extern int trace_event_trigger_enable_disable(struct trace_event_file *file,
1593 					      int trigger_enable);
1594 extern void update_cond_flag(struct trace_event_file *file);
1595 extern int set_trigger_filter(char *filter_str,
1596 			      struct event_trigger_data *trigger_data,
1597 			      struct trace_event_file *file);
1598 extern struct event_trigger_data *find_named_trigger(const char *name);
1599 extern bool is_named_trigger(struct event_trigger_data *test);
1600 extern int save_named_trigger(const char *name,
1601 			      struct event_trigger_data *data);
1602 extern void del_named_trigger(struct event_trigger_data *data);
1603 extern void pause_named_trigger(struct event_trigger_data *data);
1604 extern void unpause_named_trigger(struct event_trigger_data *data);
1605 extern void set_named_trigger_data(struct event_trigger_data *data,
1606 				   struct event_trigger_data *named_data);
1607 extern struct event_trigger_data *
1608 get_named_trigger_data(struct event_trigger_data *data);
1609 extern int register_event_command(struct event_command *cmd);
1610 extern int unregister_event_command(struct event_command *cmd);
1611 extern int register_trigger_hist_enable_disable_cmds(void);
1612 
1613 /**
1614  * struct event_trigger_ops - callbacks for trace event triggers
1615  *
1616  * The methods in this structure provide per-event trigger hooks for
1617  * various trigger operations.
1618  *
1619  * All the methods below, except for @init() and @free(), must be
1620  * implemented.
1621  *
1622  * @func: The trigger 'probe' function called when the triggering
1623  *	event occurs.  The data passed into this callback is the data
1624  *	that was supplied to the event_command @reg() function that
1625  *	registered the trigger (see struct event_command) along with
1626  *	the trace record, rec.
1627  *
1628  * @init: An optional initialization function called for the trigger
1629  *	when the trigger is registered (via the event_command reg()
1630  *	function).  This can be used to perform per-trigger
1631  *	initialization such as incrementing a per-trigger reference
1632  *	count, for instance.  This is usually implemented by the
1633  *	generic utility function @event_trigger_init() (see
1634  *	trace_event_triggers.c).
1635  *
1636  * @free: An optional de-initialization function called for the
1637  *	trigger when the trigger is unregistered (via the
1638  *	event_command @reg() function).  This can be used to perform
1639  *	per-trigger de-initialization such as decrementing a
1640  *	per-trigger reference count and freeing corresponding trigger
1641  *	data, for instance.  This is usually implemented by the
1642  *	generic utility function @event_trigger_free() (see
1643  *	trace_event_triggers.c).
1644  *
1645  * @print: The callback function invoked to have the trigger print
1646  *	itself.  This is usually implemented by a wrapper function
1647  *	that calls the generic utility function @event_trigger_print()
1648  *	(see trace_event_triggers.c).
1649  */
1650 struct event_trigger_ops {
1651 	void			(*func)(struct event_trigger_data *data,
1652 					struct trace_buffer *buffer, void *rec,
1653 					struct ring_buffer_event *rbe);
1654 	int			(*init)(struct event_trigger_ops *ops,
1655 					struct event_trigger_data *data);
1656 	void			(*free)(struct event_trigger_ops *ops,
1657 					struct event_trigger_data *data);
1658 	int			(*print)(struct seq_file *m,
1659 					 struct event_trigger_ops *ops,
1660 					 struct event_trigger_data *data);
1661 };
1662 
1663 /**
1664  * struct event_command - callbacks and data members for event commands
1665  *
1666  * Event commands are invoked by users by writing the command name
1667  * into the 'trigger' file associated with a trace event.  The
1668  * parameters associated with a specific invocation of an event
1669  * command are used to create an event trigger instance, which is
1670  * added to the list of trigger instances associated with that trace
1671  * event.  When the event is hit, the set of triggers associated with
1672  * that event is invoked.
1673  *
1674  * The data members in this structure provide per-event command data
1675  * for various event commands.
1676  *
1677  * All the data members below, except for @post_trigger, must be set
1678  * for each event command.
1679  *
1680  * @name: The unique name that identifies the event command.  This is
1681  *	the name used when setting triggers via trigger files.
1682  *
1683  * @trigger_type: A unique id that identifies the event command
1684  *	'type'.  This value has two purposes, the first to ensure that
1685  *	only one trigger of the same type can be set at a given time
1686  *	for a particular event e.g. it doesn't make sense to have both
1687  *	a traceon and traceoff trigger attached to a single event at
1688  *	the same time, so traceon and traceoff have the same type
1689  *	though they have different names.  The @trigger_type value is
1690  *	also used as a bit value for deferring the actual trigger
1691  *	action until after the current event is finished.  Some
1692  *	commands need to do this if they themselves log to the trace
1693  *	buffer (see the @post_trigger() member below).  @trigger_type
1694  *	values are defined by adding new values to the trigger_type
1695  *	enum in include/linux/trace_events.h.
1696  *
1697  * @flags: See the enum event_command_flags below.
1698  *
1699  * All the methods below, except for @set_filter() and @unreg_all(),
1700  * must be implemented.
1701  *
1702  * @func: The callback function responsible for parsing and
1703  *	registering the trigger written to the 'trigger' file by the
1704  *	user.  It allocates the trigger instance and registers it with
1705  *	the appropriate trace event.  It makes use of the other
1706  *	event_command callback functions to orchestrate this, and is
1707  *	usually implemented by the generic utility function
1708  *	@event_trigger_callback() (see trace_event_triggers.c).
1709  *
1710  * @reg: Adds the trigger to the list of triggers associated with the
1711  *	event, and enables the event trigger itself, after
1712  *	initializing it (via the event_trigger_ops @init() function).
1713  *	This is also where commands can use the @trigger_type value to
1714  *	make the decision as to whether or not multiple instances of
1715  *	the trigger should be allowed.  This is usually implemented by
1716  *	the generic utility function @register_trigger() (see
1717  *	trace_event_triggers.c).
1718  *
1719  * @unreg: Removes the trigger from the list of triggers associated
1720  *	with the event, and disables the event trigger itself, after
1721  *	initializing it (via the event_trigger_ops @free() function).
1722  *	This is usually implemented by the generic utility function
1723  *	@unregister_trigger() (see trace_event_triggers.c).
1724  *
1725  * @unreg_all: An optional function called to remove all the triggers
1726  *	from the list of triggers associated with the event.  Called
1727  *	when a trigger file is opened in truncate mode.
1728  *
1729  * @set_filter: An optional function called to parse and set a filter
1730  *	for the trigger.  If no @set_filter() method is set for the
1731  *	event command, filters set by the user for the command will be
1732  *	ignored.  This is usually implemented by the generic utility
1733  *	function @set_trigger_filter() (see trace_event_triggers.c).
1734  *
1735  * @get_trigger_ops: The callback function invoked to retrieve the
1736  *	event_trigger_ops implementation associated with the command.
1737  */
1738 struct event_command {
1739 	struct list_head	list;
1740 	char			*name;
1741 	enum event_trigger_type	trigger_type;
1742 	int			flags;
1743 	int			(*func)(struct event_command *cmd_ops,
1744 					struct trace_event_file *file,
1745 					char *glob, char *cmd, char *params);
1746 	int			(*reg)(char *glob,
1747 				       struct event_trigger_ops *ops,
1748 				       struct event_trigger_data *data,
1749 				       struct trace_event_file *file);
1750 	void			(*unreg)(char *glob,
1751 					 struct event_trigger_ops *ops,
1752 					 struct event_trigger_data *data,
1753 					 struct trace_event_file *file);
1754 	void			(*unreg_all)(struct trace_event_file *file);
1755 	int			(*set_filter)(char *filter_str,
1756 					      struct event_trigger_data *data,
1757 					      struct trace_event_file *file);
1758 	struct event_trigger_ops *(*get_trigger_ops)(char *cmd, char *param);
1759 };
1760 
1761 /**
1762  * enum event_command_flags - flags for struct event_command
1763  *
1764  * @POST_TRIGGER: A flag that says whether or not this command needs
1765  *	to have its action delayed until after the current event has
1766  *	been closed.  Some triggers need to avoid being invoked while
1767  *	an event is currently in the process of being logged, since
1768  *	the trigger may itself log data into the trace buffer.  Thus
1769  *	we make sure the current event is committed before invoking
1770  *	those triggers.  To do that, the trigger invocation is split
1771  *	in two - the first part checks the filter using the current
1772  *	trace record; if a command has the @post_trigger flag set, it
1773  *	sets a bit for itself in the return value, otherwise it
1774  *	directly invokes the trigger.  Once all commands have been
1775  *	either invoked or set their return flag, the current record is
1776  *	either committed or discarded.  At that point, if any commands
1777  *	have deferred their triggers, those commands are finally
1778  *	invoked following the close of the current event.  In other
1779  *	words, if the event_trigger_ops @func() probe implementation
1780  *	itself logs to the trace buffer, this flag should be set,
1781  *	otherwise it can be left unspecified.
1782  *
1783  * @NEEDS_REC: A flag that says whether or not this command needs
1784  *	access to the trace record in order to perform its function,
1785  *	regardless of whether or not it has a filter associated with
1786  *	it (filters make a trigger require access to the trace record
1787  *	but are not always present).
1788  */
1789 enum event_command_flags {
1790 	EVENT_CMD_FL_POST_TRIGGER	= 1,
1791 	EVENT_CMD_FL_NEEDS_REC		= 2,
1792 };
1793 
1794 static inline bool event_command_post_trigger(struct event_command *cmd_ops)
1795 {
1796 	return cmd_ops->flags & EVENT_CMD_FL_POST_TRIGGER;
1797 }
1798 
1799 static inline bool event_command_needs_rec(struct event_command *cmd_ops)
1800 {
1801 	return cmd_ops->flags & EVENT_CMD_FL_NEEDS_REC;
1802 }
1803 
1804 extern int trace_event_enable_disable(struct trace_event_file *file,
1805 				      int enable, int soft_disable);
1806 extern int tracing_alloc_snapshot(void);
1807 extern void tracing_snapshot_cond(struct trace_array *tr, void *cond_data);
1808 extern int tracing_snapshot_cond_enable(struct trace_array *tr, void *cond_data, cond_update_fn_t update);
1809 
1810 extern int tracing_snapshot_cond_disable(struct trace_array *tr);
1811 extern void *tracing_cond_snapshot_data(struct trace_array *tr);
1812 
1813 extern const char *__start___trace_bprintk_fmt[];
1814 extern const char *__stop___trace_bprintk_fmt[];
1815 
1816 extern const char *__start___tracepoint_str[];
1817 extern const char *__stop___tracepoint_str[];
1818 
1819 void trace_printk_control(bool enabled);
1820 void trace_printk_start_comm(void);
1821 int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set);
1822 int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled);
1823 
1824 /* Used from boot time tracer */
1825 extern int trace_set_options(struct trace_array *tr, char *option);
1826 extern int tracing_set_tracer(struct trace_array *tr, const char *buf);
1827 extern ssize_t tracing_resize_ring_buffer(struct trace_array *tr,
1828 					  unsigned long size, int cpu_id);
1829 extern int tracing_set_cpumask(struct trace_array *tr,
1830 				cpumask_var_t tracing_cpumask_new);
1831 
1832 
1833 #define MAX_EVENT_NAME_LEN	64
1834 
1835 extern ssize_t trace_parse_run_command(struct file *file,
1836 		const char __user *buffer, size_t count, loff_t *ppos,
1837 		int (*createfn)(const char *));
1838 
1839 extern unsigned int err_pos(char *cmd, const char *str);
1840 extern void tracing_log_err(struct trace_array *tr,
1841 			    const char *loc, const char *cmd,
1842 			    const char **errs, u8 type, u8 pos);
1843 
1844 /*
1845  * Normal trace_printk() and friends allocates special buffers
1846  * to do the manipulation, as well as saves the print formats
1847  * into sections to display. But the trace infrastructure wants
1848  * to use these without the added overhead at the price of being
1849  * a bit slower (used mainly for warnings, where we don't care
1850  * about performance). The internal_trace_puts() is for such
1851  * a purpose.
1852  */
1853 #define internal_trace_puts(str) __trace_puts(_THIS_IP_, str, strlen(str))
1854 
1855 #undef FTRACE_ENTRY
1856 #define FTRACE_ENTRY(call, struct_name, id, tstruct, print)	\
1857 	extern struct trace_event_call					\
1858 	__aligned(4) event_##call;
1859 #undef FTRACE_ENTRY_DUP
1860 #define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print)	\
1861 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
1862 #undef FTRACE_ENTRY_PACKED
1863 #define FTRACE_ENTRY_PACKED(call, struct_name, id, tstruct, print) \
1864 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
1865 
1866 #include "trace_entries.h"
1867 
1868 #if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_FUNCTION_TRACER)
1869 int perf_ftrace_event_register(struct trace_event_call *call,
1870 			       enum trace_reg type, void *data);
1871 #else
1872 #define perf_ftrace_event_register NULL
1873 #endif
1874 
1875 #ifdef CONFIG_FTRACE_SYSCALLS
1876 void init_ftrace_syscalls(void);
1877 const char *get_syscall_name(int syscall);
1878 #else
1879 static inline void init_ftrace_syscalls(void) { }
1880 static inline const char *get_syscall_name(int syscall)
1881 {
1882 	return NULL;
1883 }
1884 #endif
1885 
1886 #ifdef CONFIG_EVENT_TRACING
1887 void trace_event_init(void);
1888 void trace_event_eval_update(struct trace_eval_map **map, int len);
1889 /* Used from boot time tracer */
1890 extern int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set);
1891 extern int trigger_process_regex(struct trace_event_file *file, char *buff);
1892 #else
1893 static inline void __init trace_event_init(void) { }
1894 static inline void trace_event_eval_update(struct trace_eval_map **map, int len) { }
1895 #endif
1896 
1897 #ifdef CONFIG_TRACER_SNAPSHOT
1898 void tracing_snapshot_instance(struct trace_array *tr);
1899 int tracing_alloc_snapshot_instance(struct trace_array *tr);
1900 #else
1901 static inline void tracing_snapshot_instance(struct trace_array *tr) { }
1902 static inline int tracing_alloc_snapshot_instance(struct trace_array *tr)
1903 {
1904 	return 0;
1905 }
1906 #endif
1907 
1908 #ifdef CONFIG_PREEMPT_TRACER
1909 void tracer_preempt_on(unsigned long a0, unsigned long a1);
1910 void tracer_preempt_off(unsigned long a0, unsigned long a1);
1911 #else
1912 static inline void tracer_preempt_on(unsigned long a0, unsigned long a1) { }
1913 static inline void tracer_preempt_off(unsigned long a0, unsigned long a1) { }
1914 #endif
1915 #ifdef CONFIG_IRQSOFF_TRACER
1916 void tracer_hardirqs_on(unsigned long a0, unsigned long a1);
1917 void tracer_hardirqs_off(unsigned long a0, unsigned long a1);
1918 #else
1919 static inline void tracer_hardirqs_on(unsigned long a0, unsigned long a1) { }
1920 static inline void tracer_hardirqs_off(unsigned long a0, unsigned long a1) { }
1921 #endif
1922 
1923 extern struct trace_iterator *tracepoint_print_iter;
1924 
1925 /*
1926  * Reset the state of the trace_iterator so that it can read consumed data.
1927  * Normally, the trace_iterator is used for reading the data when it is not
1928  * consumed, and must retain state.
1929  */
1930 static __always_inline void trace_iterator_reset(struct trace_iterator *iter)
1931 {
1932 	const size_t offset = offsetof(struct trace_iterator, seq);
1933 
1934 	/*
1935 	 * Keep gcc from complaining about overwriting more than just one
1936 	 * member in the structure.
1937 	 */
1938 	memset((char *)iter + offset, 0, sizeof(struct trace_iterator) - offset);
1939 
1940 	iter->pos = -1;
1941 }
1942 
1943 /* Check the name is good for event/group/fields */
1944 static inline bool is_good_name(const char *name)
1945 {
1946 	if (!isalpha(*name) && *name != '_')
1947 		return false;
1948 	while (*++name != '\0') {
1949 		if (!isalpha(*name) && !isdigit(*name) && *name != '_')
1950 			return false;
1951 	}
1952 	return true;
1953 }
1954 
1955 #endif /* _LINUX_KERNEL_TRACE_H */
1956