xref: /linux/kernel/trace/trace.h (revision 3f41368fbfe1b3d5922d317fe1a0a0cab6846802)
1 // SPDX-License-Identifier: GPL-2.0
2 
3 #ifndef _LINUX_KERNEL_TRACE_H
4 #define _LINUX_KERNEL_TRACE_H
5 
6 #include <linux/fs.h>
7 #include <linux/atomic.h>
8 #include <linux/sched.h>
9 #include <linux/clocksource.h>
10 #include <linux/ring_buffer.h>
11 #include <linux/mmiotrace.h>
12 #include <linux/tracepoint.h>
13 #include <linux/ftrace.h>
14 #include <linux/trace.h>
15 #include <linux/hw_breakpoint.h>
16 #include <linux/trace_seq.h>
17 #include <linux/trace_events.h>
18 #include <linux/compiler.h>
19 #include <linux/glob.h>
20 #include <linux/irq_work.h>
21 #include <linux/workqueue.h>
22 #include <linux/ctype.h>
23 #include <linux/once_lite.h>
24 
25 #include "pid_list.h"
26 
27 #ifdef CONFIG_FTRACE_SYSCALLS
28 #include <asm/unistd.h>		/* For NR_syscalls	     */
29 #include <asm/syscall.h>	/* some archs define it here */
30 #endif
31 
32 #define TRACE_MODE_WRITE	0640
33 #define TRACE_MODE_READ		0440
34 
35 enum trace_type {
36 	__TRACE_FIRST_TYPE = 0,
37 
38 	TRACE_FN,
39 	TRACE_CTX,
40 	TRACE_WAKE,
41 	TRACE_STACK,
42 	TRACE_PRINT,
43 	TRACE_BPRINT,
44 	TRACE_MMIO_RW,
45 	TRACE_MMIO_MAP,
46 	TRACE_BRANCH,
47 	TRACE_GRAPH_RET,
48 	TRACE_GRAPH_ENT,
49 	TRACE_USER_STACK,
50 	TRACE_BLK,
51 	TRACE_BPUTS,
52 	TRACE_HWLAT,
53 	TRACE_OSNOISE,
54 	TRACE_TIMERLAT,
55 	TRACE_RAW_DATA,
56 	TRACE_FUNC_REPEATS,
57 
58 	__TRACE_LAST_TYPE,
59 };
60 
61 
62 #undef __field
63 #define __field(type, item)		type	item;
64 
65 #undef __field_fn
66 #define __field_fn(type, item)		type	item;
67 
68 #undef __field_struct
69 #define __field_struct(type, item)	__field(type, item)
70 
71 #undef __field_desc
72 #define __field_desc(type, container, item)
73 
74 #undef __field_packed
75 #define __field_packed(type, container, item)
76 
77 #undef __array
78 #define __array(type, item, size)	type	item[size];
79 
80 /*
81  * For backward compatibility, older user space expects to see the
82  * kernel_stack event with a fixed size caller field. But today the fix
83  * size is ignored by the kernel, and the real structure is dynamic.
84  * Expose to user space: "unsigned long caller[8];" but the real structure
85  * will be "unsigned long caller[] __counted_by(size)"
86  */
87 #undef __stack_array
88 #define __stack_array(type, item, size, field)		type item[] __counted_by(field);
89 
90 #undef __array_desc
91 #define __array_desc(type, container, item, size)
92 
93 #undef __dynamic_array
94 #define __dynamic_array(type, item)	type	item[];
95 
96 #undef __rel_dynamic_array
97 #define __rel_dynamic_array(type, item)	type	item[];
98 
99 #undef F_STRUCT
100 #define F_STRUCT(args...)		args
101 
102 #undef FTRACE_ENTRY
103 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print)		\
104 	struct struct_name {						\
105 		struct trace_entry	ent;				\
106 		tstruct							\
107 	}
108 
109 #undef FTRACE_ENTRY_DUP
110 #define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk)
111 
112 #undef FTRACE_ENTRY_REG
113 #define FTRACE_ENTRY_REG(name, struct_name, id, tstruct, print,	regfn)	\
114 	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print))
115 
116 #undef FTRACE_ENTRY_PACKED
117 #define FTRACE_ENTRY_PACKED(name, struct_name, id, tstruct, print)	\
118 	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print)) __packed
119 
120 #include "trace_entries.h"
121 
122 /* Use this for memory failure errors */
123 #define MEM_FAIL(condition, fmt, ...)					\
124 	DO_ONCE_LITE_IF(condition, pr_err, "ERROR: " fmt, ##__VA_ARGS__)
125 
126 #define FAULT_STRING "(fault)"
127 
128 #define HIST_STACKTRACE_DEPTH	16
129 #define HIST_STACKTRACE_SIZE	(HIST_STACKTRACE_DEPTH * sizeof(unsigned long))
130 #define HIST_STACKTRACE_SKIP	5
131 
132 /*
133  * syscalls are special, and need special handling, this is why
134  * they are not included in trace_entries.h
135  */
136 struct syscall_trace_enter {
137 	struct trace_entry	ent;
138 	int			nr;
139 	unsigned long		args[];
140 };
141 
142 struct syscall_trace_exit {
143 	struct trace_entry	ent;
144 	int			nr;
145 	long			ret;
146 };
147 
148 struct kprobe_trace_entry_head {
149 	struct trace_entry	ent;
150 	unsigned long		ip;
151 };
152 
153 struct eprobe_trace_entry_head {
154 	struct trace_entry	ent;
155 };
156 
157 struct kretprobe_trace_entry_head {
158 	struct trace_entry	ent;
159 	unsigned long		func;
160 	unsigned long		ret_ip;
161 };
162 
163 struct fentry_trace_entry_head {
164 	struct trace_entry	ent;
165 	unsigned long		ip;
166 };
167 
168 struct fexit_trace_entry_head {
169 	struct trace_entry	ent;
170 	unsigned long		func;
171 	unsigned long		ret_ip;
172 };
173 
174 #define TRACE_BUF_SIZE		1024
175 
176 struct trace_array;
177 
178 /*
179  * The CPU trace array - it consists of thousands of trace entries
180  * plus some other descriptor data: (for example which task started
181  * the trace, etc.)
182  */
183 struct trace_array_cpu {
184 	atomic_t		disabled;
185 	void			*buffer_page;	/* ring buffer spare */
186 
187 	unsigned long		entries;
188 	unsigned long		saved_latency;
189 	unsigned long		critical_start;
190 	unsigned long		critical_end;
191 	unsigned long		critical_sequence;
192 	unsigned long		nice;
193 	unsigned long		policy;
194 	unsigned long		rt_priority;
195 	unsigned long		skipped_entries;
196 	u64			preempt_timestamp;
197 	pid_t			pid;
198 	kuid_t			uid;
199 	char			comm[TASK_COMM_LEN];
200 
201 #ifdef CONFIG_FUNCTION_TRACER
202 	int			ftrace_ignore_pid;
203 #endif
204 	bool			ignore_pid;
205 };
206 
207 struct tracer;
208 struct trace_option_dentry;
209 
210 struct array_buffer {
211 	struct trace_array		*tr;
212 	struct trace_buffer		*buffer;
213 	struct trace_array_cpu __percpu	*data;
214 	u64				time_start;
215 	int				cpu;
216 };
217 
218 #define TRACE_FLAGS_MAX_SIZE		32
219 
220 struct trace_options {
221 	struct tracer			*tracer;
222 	struct trace_option_dentry	*topts;
223 };
224 
225 struct trace_pid_list *trace_pid_list_alloc(void);
226 void trace_pid_list_free(struct trace_pid_list *pid_list);
227 bool trace_pid_list_is_set(struct trace_pid_list *pid_list, unsigned int pid);
228 int trace_pid_list_set(struct trace_pid_list *pid_list, unsigned int pid);
229 int trace_pid_list_clear(struct trace_pid_list *pid_list, unsigned int pid);
230 int trace_pid_list_first(struct trace_pid_list *pid_list, unsigned int *pid);
231 int trace_pid_list_next(struct trace_pid_list *pid_list, unsigned int pid,
232 			unsigned int *next);
233 
234 enum {
235 	TRACE_PIDS		= BIT(0),
236 	TRACE_NO_PIDS		= BIT(1),
237 };
238 
239 static inline bool pid_type_enabled(int type, struct trace_pid_list *pid_list,
240 				    struct trace_pid_list *no_pid_list)
241 {
242 	/* Return true if the pid list in type has pids */
243 	return ((type & TRACE_PIDS) && pid_list) ||
244 		((type & TRACE_NO_PIDS) && no_pid_list);
245 }
246 
247 static inline bool still_need_pid_events(int type, struct trace_pid_list *pid_list,
248 					 struct trace_pid_list *no_pid_list)
249 {
250 	/*
251 	 * Turning off what is in @type, return true if the "other"
252 	 * pid list, still has pids in it.
253 	 */
254 	return (!(type & TRACE_PIDS) && pid_list) ||
255 		(!(type & TRACE_NO_PIDS) && no_pid_list);
256 }
257 
258 typedef bool (*cond_update_fn_t)(struct trace_array *tr, void *cond_data);
259 
260 /**
261  * struct cond_snapshot - conditional snapshot data and callback
262  *
263  * The cond_snapshot structure encapsulates a callback function and
264  * data associated with the snapshot for a given tracing instance.
265  *
266  * When a snapshot is taken conditionally, by invoking
267  * tracing_snapshot_cond(tr, cond_data), the cond_data passed in is
268  * passed in turn to the cond_snapshot.update() function.  That data
269  * can be compared by the update() implementation with the cond_data
270  * contained within the struct cond_snapshot instance associated with
271  * the trace_array.  Because the tr->max_lock is held throughout the
272  * update() call, the update() function can directly retrieve the
273  * cond_snapshot and cond_data associated with the per-instance
274  * snapshot associated with the trace_array.
275  *
276  * The cond_snapshot.update() implementation can save data to be
277  * associated with the snapshot if it decides to, and returns 'true'
278  * in that case, or it returns 'false' if the conditional snapshot
279  * shouldn't be taken.
280  *
281  * The cond_snapshot instance is created and associated with the
282  * user-defined cond_data by tracing_cond_snapshot_enable().
283  * Likewise, the cond_snapshot instance is destroyed and is no longer
284  * associated with the trace instance by
285  * tracing_cond_snapshot_disable().
286  *
287  * The method below is required.
288  *
289  * @update: When a conditional snapshot is invoked, the update()
290  *	callback function is invoked with the tr->max_lock held.  The
291  *	update() implementation signals whether or not to actually
292  *	take the snapshot, by returning 'true' if so, 'false' if no
293  *	snapshot should be taken.  Because the max_lock is held for
294  *	the duration of update(), the implementation is safe to
295  *	directly retrieved and save any implementation data it needs
296  *	to in association with the snapshot.
297  */
298 struct cond_snapshot {
299 	void				*cond_data;
300 	cond_update_fn_t		update;
301 };
302 
303 /*
304  * struct trace_func_repeats - used to keep track of the consecutive
305  * (on the same CPU) calls of a single function.
306  */
307 struct trace_func_repeats {
308 	unsigned long	ip;
309 	unsigned long	parent_ip;
310 	unsigned long	count;
311 	u64		ts_last_call;
312 };
313 
314 /*
315  * The trace array - an array of per-CPU trace arrays. This is the
316  * highest level data structure that individual tracers deal with.
317  * They have on/off state as well:
318  */
319 struct trace_array {
320 	struct list_head	list;
321 	char			*name;
322 	struct array_buffer	array_buffer;
323 #ifdef CONFIG_TRACER_MAX_TRACE
324 	/*
325 	 * The max_buffer is used to snapshot the trace when a maximum
326 	 * latency is reached, or when the user initiates a snapshot.
327 	 * Some tracers will use this to store a maximum trace while
328 	 * it continues examining live traces.
329 	 *
330 	 * The buffers for the max_buffer are set up the same as the array_buffer
331 	 * When a snapshot is taken, the buffer of the max_buffer is swapped
332 	 * with the buffer of the array_buffer and the buffers are reset for
333 	 * the array_buffer so the tracing can continue.
334 	 */
335 	struct array_buffer	max_buffer;
336 	bool			allocated_snapshot;
337 	spinlock_t		snapshot_trigger_lock;
338 	unsigned int		snapshot;
339 	unsigned int		mapped;
340 	unsigned long		max_latency;
341 #ifdef CONFIG_FSNOTIFY
342 	struct dentry		*d_max_latency;
343 	struct work_struct	fsnotify_work;
344 	struct irq_work		fsnotify_irqwork;
345 #endif
346 #endif
347 	struct trace_pid_list	__rcu *filtered_pids;
348 	struct trace_pid_list	__rcu *filtered_no_pids;
349 	/*
350 	 * max_lock is used to protect the swapping of buffers
351 	 * when taking a max snapshot. The buffers themselves are
352 	 * protected by per_cpu spinlocks. But the action of the swap
353 	 * needs its own lock.
354 	 *
355 	 * This is defined as a arch_spinlock_t in order to help
356 	 * with performance when lockdep debugging is enabled.
357 	 *
358 	 * It is also used in other places outside the update_max_tr
359 	 * so it needs to be defined outside of the
360 	 * CONFIG_TRACER_MAX_TRACE.
361 	 */
362 	arch_spinlock_t		max_lock;
363 	int			buffer_disabled;
364 #ifdef CONFIG_FTRACE_SYSCALLS
365 	int			sys_refcount_enter;
366 	int			sys_refcount_exit;
367 	struct trace_event_file __rcu *enter_syscall_files[NR_syscalls];
368 	struct trace_event_file __rcu *exit_syscall_files[NR_syscalls];
369 #endif
370 	int			stop_count;
371 	int			clock_id;
372 	int			nr_topts;
373 	bool			clear_trace;
374 	int			buffer_percent;
375 	unsigned int		n_err_log_entries;
376 	struct tracer		*current_trace;
377 	unsigned int		trace_flags;
378 	unsigned char		trace_flags_index[TRACE_FLAGS_MAX_SIZE];
379 	unsigned int		flags;
380 	raw_spinlock_t		start_lock;
381 	const char		*system_names;
382 	struct list_head	err_log;
383 	struct dentry		*dir;
384 	struct dentry		*options;
385 	struct dentry		*percpu_dir;
386 	struct eventfs_inode	*event_dir;
387 	struct trace_options	*topts;
388 	struct list_head	systems;
389 	struct list_head	events;
390 	struct trace_event_file *trace_marker_file;
391 	cpumask_var_t		tracing_cpumask; /* only trace on set CPUs */
392 	/* one per_cpu trace_pipe can be opened by only one user */
393 	cpumask_var_t		pipe_cpumask;
394 	int			ref;
395 	int			trace_ref;
396 #ifdef CONFIG_FUNCTION_TRACER
397 	struct ftrace_ops	*ops;
398 	struct trace_pid_list	__rcu *function_pids;
399 	struct trace_pid_list	__rcu *function_no_pids;
400 #ifdef CONFIG_DYNAMIC_FTRACE
401 	/* All of these are protected by the ftrace_lock */
402 	struct list_head	func_probes;
403 	struct list_head	mod_trace;
404 	struct list_head	mod_notrace;
405 #endif
406 	/* function tracing enabled */
407 	int			function_enabled;
408 #endif
409 	int			no_filter_buffering_ref;
410 	struct list_head	hist_vars;
411 #ifdef CONFIG_TRACER_SNAPSHOT
412 	struct cond_snapshot	*cond_snapshot;
413 #endif
414 	struct trace_func_repeats	__percpu *last_func_repeats;
415 	/*
416 	 * On boot up, the ring buffer is set to the minimum size, so that
417 	 * we do not waste memory on systems that are not using tracing.
418 	 */
419 	bool ring_buffer_expanded;
420 };
421 
422 enum {
423 	TRACE_ARRAY_FL_GLOBAL	= (1 << 0)
424 };
425 
426 extern struct list_head ftrace_trace_arrays;
427 
428 extern struct mutex trace_types_lock;
429 
430 extern int trace_array_get(struct trace_array *tr);
431 extern int tracing_check_open_get_tr(struct trace_array *tr);
432 extern struct trace_array *trace_array_find(const char *instance);
433 extern struct trace_array *trace_array_find_get(const char *instance);
434 
435 extern u64 tracing_event_time_stamp(struct trace_buffer *buffer, struct ring_buffer_event *rbe);
436 extern int tracing_set_filter_buffering(struct trace_array *tr, bool set);
437 extern int tracing_set_clock(struct trace_array *tr, const char *clockstr);
438 
439 extern bool trace_clock_in_ns(struct trace_array *tr);
440 
441 /*
442  * The global tracer (top) should be the first trace array added,
443  * but we check the flag anyway.
444  */
445 static inline struct trace_array *top_trace_array(void)
446 {
447 	struct trace_array *tr;
448 
449 	if (list_empty(&ftrace_trace_arrays))
450 		return NULL;
451 
452 	tr = list_entry(ftrace_trace_arrays.prev,
453 			typeof(*tr), list);
454 	WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
455 	return tr;
456 }
457 
458 #define FTRACE_CMP_TYPE(var, type) \
459 	__builtin_types_compatible_p(typeof(var), type *)
460 
461 #undef IF_ASSIGN
462 #define IF_ASSIGN(var, entry, etype, id)			\
463 	if (FTRACE_CMP_TYPE(var, etype)) {			\
464 		var = (typeof(var))(entry);			\
465 		WARN_ON(id != 0 && (entry)->type != id);	\
466 		break;						\
467 	}
468 
469 /* Will cause compile errors if type is not found. */
470 extern void __ftrace_bad_type(void);
471 
472 /*
473  * The trace_assign_type is a verifier that the entry type is
474  * the same as the type being assigned. To add new types simply
475  * add a line with the following format:
476  *
477  * IF_ASSIGN(var, ent, type, id);
478  *
479  *  Where "type" is the trace type that includes the trace_entry
480  *  as the "ent" item. And "id" is the trace identifier that is
481  *  used in the trace_type enum.
482  *
483  *  If the type can have more than one id, then use zero.
484  */
485 #define trace_assign_type(var, ent)					\
486 	do {								\
487 		IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);	\
488 		IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);	\
489 		IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);	\
490 		IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
491 		IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);	\
492 		IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT);	\
493 		IF_ASSIGN(var, ent, struct bputs_entry, TRACE_BPUTS);	\
494 		IF_ASSIGN(var, ent, struct hwlat_entry, TRACE_HWLAT);	\
495 		IF_ASSIGN(var, ent, struct osnoise_entry, TRACE_OSNOISE);\
496 		IF_ASSIGN(var, ent, struct timerlat_entry, TRACE_TIMERLAT);\
497 		IF_ASSIGN(var, ent, struct raw_data_entry, TRACE_RAW_DATA);\
498 		IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,		\
499 			  TRACE_MMIO_RW);				\
500 		IF_ASSIGN(var, ent, struct trace_mmiotrace_map,		\
501 			  TRACE_MMIO_MAP);				\
502 		IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
503 		IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,	\
504 			  TRACE_GRAPH_ENT);		\
505 		IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,	\
506 			  TRACE_GRAPH_RET);		\
507 		IF_ASSIGN(var, ent, struct func_repeats_entry,		\
508 			  TRACE_FUNC_REPEATS);				\
509 		__ftrace_bad_type();					\
510 	} while (0)
511 
512 /*
513  * An option specific to a tracer. This is a boolean value.
514  * The bit is the bit index that sets its value on the
515  * flags value in struct tracer_flags.
516  */
517 struct tracer_opt {
518 	const char	*name; /* Will appear on the trace_options file */
519 	u32		bit; /* Mask assigned in val field in tracer_flags */
520 };
521 
522 /*
523  * The set of specific options for a tracer. Your tracer
524  * have to set the initial value of the flags val.
525  */
526 struct tracer_flags {
527 	u32			val;
528 	struct tracer_opt	*opts;
529 	struct tracer		*trace;
530 };
531 
532 /* Makes more easy to define a tracer opt */
533 #define TRACER_OPT(s, b)	.name = #s, .bit = b
534 
535 
536 struct trace_option_dentry {
537 	struct tracer_opt		*opt;
538 	struct tracer_flags		*flags;
539 	struct trace_array		*tr;
540 	struct dentry			*entry;
541 };
542 
543 /**
544  * struct tracer - a specific tracer and its callbacks to interact with tracefs
545  * @name: the name chosen to select it on the available_tracers file
546  * @init: called when one switches to this tracer (echo name > current_tracer)
547  * @reset: called when one switches to another tracer
548  * @start: called when tracing is unpaused (echo 1 > tracing_on)
549  * @stop: called when tracing is paused (echo 0 > tracing_on)
550  * @update_thresh: called when tracing_thresh is updated
551  * @open: called when the trace file is opened
552  * @pipe_open: called when the trace_pipe file is opened
553  * @close: called when the trace file is released
554  * @pipe_close: called when the trace_pipe file is released
555  * @read: override the default read callback on trace_pipe
556  * @splice_read: override the default splice_read callback on trace_pipe
557  * @selftest: selftest to run on boot (see trace_selftest.c)
558  * @print_headers: override the first lines that describe your columns
559  * @print_line: callback that prints a trace
560  * @set_flag: signals one of your private flags changed (trace_options file)
561  * @flags: your private flags
562  */
563 struct tracer {
564 	const char		*name;
565 	int			(*init)(struct trace_array *tr);
566 	void			(*reset)(struct trace_array *tr);
567 	void			(*start)(struct trace_array *tr);
568 	void			(*stop)(struct trace_array *tr);
569 	int			(*update_thresh)(struct trace_array *tr);
570 	void			(*open)(struct trace_iterator *iter);
571 	void			(*pipe_open)(struct trace_iterator *iter);
572 	void			(*close)(struct trace_iterator *iter);
573 	void			(*pipe_close)(struct trace_iterator *iter);
574 	ssize_t			(*read)(struct trace_iterator *iter,
575 					struct file *filp, char __user *ubuf,
576 					size_t cnt, loff_t *ppos);
577 	ssize_t			(*splice_read)(struct trace_iterator *iter,
578 					       struct file *filp,
579 					       loff_t *ppos,
580 					       struct pipe_inode_info *pipe,
581 					       size_t len,
582 					       unsigned int flags);
583 #ifdef CONFIG_FTRACE_STARTUP_TEST
584 	int			(*selftest)(struct tracer *trace,
585 					    struct trace_array *tr);
586 #endif
587 	void			(*print_header)(struct seq_file *m);
588 	enum print_line_t	(*print_line)(struct trace_iterator *iter);
589 	/* If you handled the flag setting, return 0 */
590 	int			(*set_flag)(struct trace_array *tr,
591 					    u32 old_flags, u32 bit, int set);
592 	/* Return 0 if OK with change, else return non-zero */
593 	int			(*flag_changed)(struct trace_array *tr,
594 						u32 mask, int set);
595 	struct tracer		*next;
596 	struct tracer_flags	*flags;
597 	int			enabled;
598 	bool			print_max;
599 	bool			allow_instances;
600 #ifdef CONFIG_TRACER_MAX_TRACE
601 	bool			use_max_tr;
602 #endif
603 	/* True if tracer cannot be enabled in kernel param */
604 	bool			noboot;
605 };
606 
607 static inline struct ring_buffer_iter *
608 trace_buffer_iter(struct trace_iterator *iter, int cpu)
609 {
610 	return iter->buffer_iter ? iter->buffer_iter[cpu] : NULL;
611 }
612 
613 int tracer_init(struct tracer *t, struct trace_array *tr);
614 int tracing_is_enabled(void);
615 void tracing_reset_online_cpus(struct array_buffer *buf);
616 void tracing_reset_all_online_cpus(void);
617 void tracing_reset_all_online_cpus_unlocked(void);
618 int tracing_open_generic(struct inode *inode, struct file *filp);
619 int tracing_open_generic_tr(struct inode *inode, struct file *filp);
620 int tracing_release_generic_tr(struct inode *inode, struct file *file);
621 int tracing_open_file_tr(struct inode *inode, struct file *filp);
622 int tracing_release_file_tr(struct inode *inode, struct file *filp);
623 int tracing_single_release_file_tr(struct inode *inode, struct file *filp);
624 bool tracing_is_disabled(void);
625 bool tracer_tracing_is_on(struct trace_array *tr);
626 void tracer_tracing_on(struct trace_array *tr);
627 void tracer_tracing_off(struct trace_array *tr);
628 struct dentry *trace_create_file(const char *name,
629 				 umode_t mode,
630 				 struct dentry *parent,
631 				 void *data,
632 				 const struct file_operations *fops);
633 
634 int tracing_init_dentry(void);
635 
636 struct ring_buffer_event;
637 
638 struct ring_buffer_event *
639 trace_buffer_lock_reserve(struct trace_buffer *buffer,
640 			  int type,
641 			  unsigned long len,
642 			  unsigned int trace_ctx);
643 
644 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
645 						struct trace_array_cpu *data);
646 
647 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
648 					  int *ent_cpu, u64 *ent_ts);
649 
650 void trace_buffer_unlock_commit_nostack(struct trace_buffer *buffer,
651 					struct ring_buffer_event *event);
652 
653 bool trace_is_tracepoint_string(const char *str);
654 const char *trace_event_format(struct trace_iterator *iter, const char *fmt);
655 void trace_check_vprintf(struct trace_iterator *iter, const char *fmt,
656 			 va_list ap) __printf(2, 0);
657 char *trace_iter_expand_format(struct trace_iterator *iter);
658 
659 int trace_empty(struct trace_iterator *iter);
660 
661 void *trace_find_next_entry_inc(struct trace_iterator *iter);
662 
663 void trace_init_global_iter(struct trace_iterator *iter);
664 
665 void tracing_iter_reset(struct trace_iterator *iter, int cpu);
666 
667 unsigned long trace_total_entries_cpu(struct trace_array *tr, int cpu);
668 unsigned long trace_total_entries(struct trace_array *tr);
669 
670 void trace_function(struct trace_array *tr,
671 		    unsigned long ip,
672 		    unsigned long parent_ip,
673 		    unsigned int trace_ctx);
674 void trace_graph_function(struct trace_array *tr,
675 		    unsigned long ip,
676 		    unsigned long parent_ip,
677 		    unsigned int trace_ctx);
678 void trace_latency_header(struct seq_file *m);
679 void trace_default_header(struct seq_file *m);
680 void print_trace_header(struct seq_file *m, struct trace_iterator *iter);
681 
682 void trace_graph_return(struct ftrace_graph_ret *trace);
683 int trace_graph_entry(struct ftrace_graph_ent *trace);
684 void set_graph_array(struct trace_array *tr);
685 
686 void tracing_start_cmdline_record(void);
687 void tracing_stop_cmdline_record(void);
688 void tracing_start_tgid_record(void);
689 void tracing_stop_tgid_record(void);
690 
691 int register_tracer(struct tracer *type);
692 int is_tracing_stopped(void);
693 
694 loff_t tracing_lseek(struct file *file, loff_t offset, int whence);
695 
696 extern cpumask_var_t __read_mostly tracing_buffer_mask;
697 
698 #define for_each_tracing_cpu(cpu)	\
699 	for_each_cpu(cpu, tracing_buffer_mask)
700 
701 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
702 
703 extern unsigned long tracing_thresh;
704 
705 /* PID filtering */
706 
707 extern int pid_max;
708 
709 bool trace_find_filtered_pid(struct trace_pid_list *filtered_pids,
710 			     pid_t search_pid);
711 bool trace_ignore_this_task(struct trace_pid_list *filtered_pids,
712 			    struct trace_pid_list *filtered_no_pids,
713 			    struct task_struct *task);
714 void trace_filter_add_remove_task(struct trace_pid_list *pid_list,
715 				  struct task_struct *self,
716 				  struct task_struct *task);
717 void *trace_pid_next(struct trace_pid_list *pid_list, void *v, loff_t *pos);
718 void *trace_pid_start(struct trace_pid_list *pid_list, loff_t *pos);
719 int trace_pid_show(struct seq_file *m, void *v);
720 int trace_pid_write(struct trace_pid_list *filtered_pids,
721 		    struct trace_pid_list **new_pid_list,
722 		    const char __user *ubuf, size_t cnt);
723 
724 #ifdef CONFIG_TRACER_MAX_TRACE
725 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu,
726 		   void *cond_data);
727 void update_max_tr_single(struct trace_array *tr,
728 			  struct task_struct *tsk, int cpu);
729 
730 #ifdef CONFIG_FSNOTIFY
731 #define LATENCY_FS_NOTIFY
732 #endif
733 #endif /* CONFIG_TRACER_MAX_TRACE */
734 
735 #ifdef LATENCY_FS_NOTIFY
736 void latency_fsnotify(struct trace_array *tr);
737 #else
738 static inline void latency_fsnotify(struct trace_array *tr) { }
739 #endif
740 
741 #ifdef CONFIG_STACKTRACE
742 void __trace_stack(struct trace_array *tr, unsigned int trace_ctx, int skip);
743 #else
744 static inline void __trace_stack(struct trace_array *tr, unsigned int trace_ctx,
745 				 int skip)
746 {
747 }
748 #endif /* CONFIG_STACKTRACE */
749 
750 void trace_last_func_repeats(struct trace_array *tr,
751 			     struct trace_func_repeats *last_info,
752 			     unsigned int trace_ctx);
753 
754 extern u64 ftrace_now(int cpu);
755 
756 extern void trace_find_cmdline(int pid, char comm[]);
757 extern int trace_find_tgid(int pid);
758 extern void trace_event_follow_fork(struct trace_array *tr, bool enable);
759 
760 #ifdef CONFIG_DYNAMIC_FTRACE
761 extern unsigned long ftrace_update_tot_cnt;
762 extern unsigned long ftrace_number_of_pages;
763 extern unsigned long ftrace_number_of_groups;
764 void ftrace_init_trace_array(struct trace_array *tr);
765 #else
766 static inline void ftrace_init_trace_array(struct trace_array *tr) { }
767 #endif
768 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
769 extern int DYN_FTRACE_TEST_NAME(void);
770 #define DYN_FTRACE_TEST_NAME2 trace_selftest_dynamic_test_func2
771 extern int DYN_FTRACE_TEST_NAME2(void);
772 
773 extern void trace_set_ring_buffer_expanded(struct trace_array *tr);
774 extern bool tracing_selftest_disabled;
775 
776 #ifdef CONFIG_FTRACE_STARTUP_TEST
777 extern void __init disable_tracing_selftest(const char *reason);
778 
779 extern int trace_selftest_startup_function(struct tracer *trace,
780 					   struct trace_array *tr);
781 extern int trace_selftest_startup_function_graph(struct tracer *trace,
782 						 struct trace_array *tr);
783 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
784 					  struct trace_array *tr);
785 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
786 					     struct trace_array *tr);
787 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
788 						 struct trace_array *tr);
789 extern int trace_selftest_startup_wakeup(struct tracer *trace,
790 					 struct trace_array *tr);
791 extern int trace_selftest_startup_nop(struct tracer *trace,
792 					 struct trace_array *tr);
793 extern int trace_selftest_startup_branch(struct tracer *trace,
794 					 struct trace_array *tr);
795 /*
796  * Tracer data references selftest functions that only occur
797  * on boot up. These can be __init functions. Thus, when selftests
798  * are enabled, then the tracers need to reference __init functions.
799  */
800 #define __tracer_data		__refdata
801 #else
802 static inline void __init disable_tracing_selftest(const char *reason)
803 {
804 }
805 /* Tracers are seldom changed. Optimize when selftests are disabled. */
806 #define __tracer_data		__read_mostly
807 #endif /* CONFIG_FTRACE_STARTUP_TEST */
808 
809 extern void *head_page(struct trace_array_cpu *data);
810 extern unsigned long long ns2usecs(u64 nsec);
811 extern int
812 trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
813 extern int
814 trace_vprintk(unsigned long ip, const char *fmt, va_list args);
815 extern int
816 trace_array_vprintk(struct trace_array *tr,
817 		    unsigned long ip, const char *fmt, va_list args);
818 int trace_array_printk_buf(struct trace_buffer *buffer,
819 			   unsigned long ip, const char *fmt, ...);
820 void trace_printk_seq(struct trace_seq *s);
821 enum print_line_t print_trace_line(struct trace_iterator *iter);
822 
823 extern char trace_find_mark(unsigned long long duration);
824 
825 struct ftrace_hash;
826 
827 struct ftrace_mod_load {
828 	struct list_head	list;
829 	char			*func;
830 	char			*module;
831 	int			 enable;
832 };
833 
834 enum {
835 	FTRACE_HASH_FL_MOD	= (1 << 0),
836 };
837 
838 struct ftrace_hash {
839 	unsigned long		size_bits;
840 	struct hlist_head	*buckets;
841 	unsigned long		count;
842 	unsigned long		flags;
843 	struct rcu_head		rcu;
844 };
845 
846 struct ftrace_func_entry *
847 ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip);
848 
849 static __always_inline bool ftrace_hash_empty(struct ftrace_hash *hash)
850 {
851 	return !hash || !(hash->count || (hash->flags & FTRACE_HASH_FL_MOD));
852 }
853 
854 /* Standard output formatting function used for function return traces */
855 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
856 
857 /* Flag options */
858 #define TRACE_GRAPH_PRINT_OVERRUN       0x1
859 #define TRACE_GRAPH_PRINT_CPU           0x2
860 #define TRACE_GRAPH_PRINT_OVERHEAD      0x4
861 #define TRACE_GRAPH_PRINT_PROC          0x8
862 #define TRACE_GRAPH_PRINT_DURATION      0x10
863 #define TRACE_GRAPH_PRINT_ABS_TIME      0x20
864 #define TRACE_GRAPH_PRINT_REL_TIME      0x40
865 #define TRACE_GRAPH_PRINT_IRQS          0x80
866 #define TRACE_GRAPH_PRINT_TAIL          0x100
867 #define TRACE_GRAPH_SLEEP_TIME          0x200
868 #define TRACE_GRAPH_GRAPH_TIME          0x400
869 #define TRACE_GRAPH_PRINT_RETVAL        0x800
870 #define TRACE_GRAPH_PRINT_RETVAL_HEX    0x1000
871 #define TRACE_GRAPH_PRINT_FILL_SHIFT	28
872 #define TRACE_GRAPH_PRINT_FILL_MASK	(0x3 << TRACE_GRAPH_PRINT_FILL_SHIFT)
873 
874 extern void ftrace_graph_sleep_time_control(bool enable);
875 
876 #ifdef CONFIG_FUNCTION_PROFILER
877 extern void ftrace_graph_graph_time_control(bool enable);
878 #else
879 static inline void ftrace_graph_graph_time_control(bool enable) { }
880 #endif
881 
882 extern enum print_line_t
883 print_graph_function_flags(struct trace_iterator *iter, u32 flags);
884 extern void print_graph_headers_flags(struct seq_file *s, u32 flags);
885 extern void
886 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
887 extern void graph_trace_open(struct trace_iterator *iter);
888 extern void graph_trace_close(struct trace_iterator *iter);
889 extern int __trace_graph_entry(struct trace_array *tr,
890 			       struct ftrace_graph_ent *trace,
891 			       unsigned int trace_ctx);
892 extern void __trace_graph_return(struct trace_array *tr,
893 				 struct ftrace_graph_ret *trace,
894 				 unsigned int trace_ctx);
895 
896 #ifdef CONFIG_DYNAMIC_FTRACE
897 extern struct ftrace_hash __rcu *ftrace_graph_hash;
898 extern struct ftrace_hash __rcu *ftrace_graph_notrace_hash;
899 
900 static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace)
901 {
902 	unsigned long addr = trace->func;
903 	int ret = 0;
904 	struct ftrace_hash *hash;
905 
906 	preempt_disable_notrace();
907 
908 	/*
909 	 * Have to open code "rcu_dereference_sched()" because the
910 	 * function graph tracer can be called when RCU is not
911 	 * "watching".
912 	 * Protected with schedule_on_each_cpu(ftrace_sync)
913 	 */
914 	hash = rcu_dereference_protected(ftrace_graph_hash, !preemptible());
915 
916 	if (ftrace_hash_empty(hash)) {
917 		ret = 1;
918 		goto out;
919 	}
920 
921 	if (ftrace_lookup_ip(hash, addr)) {
922 
923 		/*
924 		 * This needs to be cleared on the return functions
925 		 * when the depth is zero.
926 		 */
927 		trace_recursion_set(TRACE_GRAPH_BIT);
928 		trace_recursion_set_depth(trace->depth);
929 
930 		/*
931 		 * If no irqs are to be traced, but a set_graph_function
932 		 * is set, and called by an interrupt handler, we still
933 		 * want to trace it.
934 		 */
935 		if (in_hardirq())
936 			trace_recursion_set(TRACE_IRQ_BIT);
937 		else
938 			trace_recursion_clear(TRACE_IRQ_BIT);
939 		ret = 1;
940 	}
941 
942 out:
943 	preempt_enable_notrace();
944 	return ret;
945 }
946 
947 static inline void ftrace_graph_addr_finish(struct ftrace_graph_ret *trace)
948 {
949 	if (trace_recursion_test(TRACE_GRAPH_BIT) &&
950 	    trace->depth == trace_recursion_depth())
951 		trace_recursion_clear(TRACE_GRAPH_BIT);
952 }
953 
954 static inline int ftrace_graph_notrace_addr(unsigned long addr)
955 {
956 	int ret = 0;
957 	struct ftrace_hash *notrace_hash;
958 
959 	preempt_disable_notrace();
960 
961 	/*
962 	 * Have to open code "rcu_dereference_sched()" because the
963 	 * function graph tracer can be called when RCU is not
964 	 * "watching".
965 	 * Protected with schedule_on_each_cpu(ftrace_sync)
966 	 */
967 	notrace_hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
968 						 !preemptible());
969 
970 	if (ftrace_lookup_ip(notrace_hash, addr))
971 		ret = 1;
972 
973 	preempt_enable_notrace();
974 	return ret;
975 }
976 #else
977 static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace)
978 {
979 	return 1;
980 }
981 
982 static inline int ftrace_graph_notrace_addr(unsigned long addr)
983 {
984 	return 0;
985 }
986 static inline void ftrace_graph_addr_finish(struct ftrace_graph_ret *trace)
987 { }
988 #endif /* CONFIG_DYNAMIC_FTRACE */
989 
990 extern unsigned int fgraph_max_depth;
991 
992 static inline bool ftrace_graph_ignore_func(struct ftrace_graph_ent *trace)
993 {
994 	/* trace it when it is-nested-in or is a function enabled. */
995 	return !(trace_recursion_test(TRACE_GRAPH_BIT) ||
996 		 ftrace_graph_addr(trace)) ||
997 		(trace->depth < 0) ||
998 		(fgraph_max_depth && trace->depth >= fgraph_max_depth);
999 }
1000 
1001 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
1002 static inline enum print_line_t
1003 print_graph_function_flags(struct trace_iterator *iter, u32 flags)
1004 {
1005 	return TRACE_TYPE_UNHANDLED;
1006 }
1007 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
1008 
1009 extern struct list_head ftrace_pids;
1010 
1011 #ifdef CONFIG_FUNCTION_TRACER
1012 
1013 #define FTRACE_PID_IGNORE	-1
1014 #define FTRACE_PID_TRACE	-2
1015 
1016 struct ftrace_func_command {
1017 	struct list_head	list;
1018 	char			*name;
1019 	int			(*func)(struct trace_array *tr,
1020 					struct ftrace_hash *hash,
1021 					char *func, char *cmd,
1022 					char *params, int enable);
1023 };
1024 extern bool ftrace_filter_param __initdata;
1025 static inline int ftrace_trace_task(struct trace_array *tr)
1026 {
1027 	return this_cpu_read(tr->array_buffer.data->ftrace_ignore_pid) !=
1028 		FTRACE_PID_IGNORE;
1029 }
1030 extern int ftrace_is_dead(void);
1031 int ftrace_create_function_files(struct trace_array *tr,
1032 				 struct dentry *parent);
1033 void ftrace_destroy_function_files(struct trace_array *tr);
1034 int ftrace_allocate_ftrace_ops(struct trace_array *tr);
1035 void ftrace_free_ftrace_ops(struct trace_array *tr);
1036 void ftrace_init_global_array_ops(struct trace_array *tr);
1037 void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func);
1038 void ftrace_reset_array_ops(struct trace_array *tr);
1039 void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer);
1040 void ftrace_init_tracefs_toplevel(struct trace_array *tr,
1041 				  struct dentry *d_tracer);
1042 void ftrace_clear_pids(struct trace_array *tr);
1043 int init_function_trace(void);
1044 void ftrace_pid_follow_fork(struct trace_array *tr, bool enable);
1045 #else
1046 static inline int ftrace_trace_task(struct trace_array *tr)
1047 {
1048 	return 1;
1049 }
1050 static inline int ftrace_is_dead(void) { return 0; }
1051 static inline int
1052 ftrace_create_function_files(struct trace_array *tr,
1053 			     struct dentry *parent)
1054 {
1055 	return 0;
1056 }
1057 static inline int ftrace_allocate_ftrace_ops(struct trace_array *tr)
1058 {
1059 	return 0;
1060 }
1061 static inline void ftrace_free_ftrace_ops(struct trace_array *tr) { }
1062 static inline void ftrace_destroy_function_files(struct trace_array *tr) { }
1063 static inline __init void
1064 ftrace_init_global_array_ops(struct trace_array *tr) { }
1065 static inline void ftrace_reset_array_ops(struct trace_array *tr) { }
1066 static inline void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d) { }
1067 static inline void ftrace_init_tracefs_toplevel(struct trace_array *tr, struct dentry *d) { }
1068 static inline void ftrace_clear_pids(struct trace_array *tr) { }
1069 static inline int init_function_trace(void) { return 0; }
1070 static inline void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) { }
1071 /* ftace_func_t type is not defined, use macro instead of static inline */
1072 #define ftrace_init_array_ops(tr, func) do { } while (0)
1073 #endif /* CONFIG_FUNCTION_TRACER */
1074 
1075 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
1076 
1077 struct ftrace_probe_ops {
1078 	void			(*func)(unsigned long ip,
1079 					unsigned long parent_ip,
1080 					struct trace_array *tr,
1081 					struct ftrace_probe_ops *ops,
1082 					void *data);
1083 	int			(*init)(struct ftrace_probe_ops *ops,
1084 					struct trace_array *tr,
1085 					unsigned long ip, void *init_data,
1086 					void **data);
1087 	void			(*free)(struct ftrace_probe_ops *ops,
1088 					struct trace_array *tr,
1089 					unsigned long ip, void *data);
1090 	int			(*print)(struct seq_file *m,
1091 					 unsigned long ip,
1092 					 struct ftrace_probe_ops *ops,
1093 					 void *data);
1094 };
1095 
1096 struct ftrace_func_mapper;
1097 typedef int (*ftrace_mapper_func)(void *data);
1098 
1099 struct ftrace_func_mapper *allocate_ftrace_func_mapper(void);
1100 void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
1101 					   unsigned long ip);
1102 int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
1103 			       unsigned long ip, void *data);
1104 void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
1105 				   unsigned long ip);
1106 void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
1107 			     ftrace_mapper_func free_func);
1108 
1109 extern int
1110 register_ftrace_function_probe(char *glob, struct trace_array *tr,
1111 			       struct ftrace_probe_ops *ops, void *data);
1112 extern int
1113 unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
1114 				      struct ftrace_probe_ops *ops);
1115 extern void clear_ftrace_function_probes(struct trace_array *tr);
1116 
1117 int register_ftrace_command(struct ftrace_func_command *cmd);
1118 int unregister_ftrace_command(struct ftrace_func_command *cmd);
1119 
1120 void ftrace_create_filter_files(struct ftrace_ops *ops,
1121 				struct dentry *parent);
1122 void ftrace_destroy_filter_files(struct ftrace_ops *ops);
1123 
1124 extern int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
1125 			     int len, int reset);
1126 extern int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
1127 			      int len, int reset);
1128 #else
1129 struct ftrace_func_command;
1130 
1131 static inline __init int register_ftrace_command(struct ftrace_func_command *cmd)
1132 {
1133 	return -EINVAL;
1134 }
1135 static inline __init int unregister_ftrace_command(char *cmd_name)
1136 {
1137 	return -EINVAL;
1138 }
1139 static inline void clear_ftrace_function_probes(struct trace_array *tr)
1140 {
1141 }
1142 
1143 /*
1144  * The ops parameter passed in is usually undefined.
1145  * This must be a macro.
1146  */
1147 #define ftrace_create_filter_files(ops, parent) do { } while (0)
1148 #define ftrace_destroy_filter_files(ops) do { } while (0)
1149 #endif /* CONFIG_FUNCTION_TRACER && CONFIG_DYNAMIC_FTRACE */
1150 
1151 bool ftrace_event_is_function(struct trace_event_call *call);
1152 
1153 /*
1154  * struct trace_parser - servers for reading the user input separated by spaces
1155  * @cont: set if the input is not complete - no final space char was found
1156  * @buffer: holds the parsed user input
1157  * @idx: user input length
1158  * @size: buffer size
1159  */
1160 struct trace_parser {
1161 	bool		cont;
1162 	char		*buffer;
1163 	unsigned	idx;
1164 	unsigned	size;
1165 };
1166 
1167 static inline bool trace_parser_loaded(struct trace_parser *parser)
1168 {
1169 	return (parser->idx != 0);
1170 }
1171 
1172 static inline bool trace_parser_cont(struct trace_parser *parser)
1173 {
1174 	return parser->cont;
1175 }
1176 
1177 static inline void trace_parser_clear(struct trace_parser *parser)
1178 {
1179 	parser->cont = false;
1180 	parser->idx = 0;
1181 }
1182 
1183 extern int trace_parser_get_init(struct trace_parser *parser, int size);
1184 extern void trace_parser_put(struct trace_parser *parser);
1185 extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
1186 	size_t cnt, loff_t *ppos);
1187 
1188 /*
1189  * Only create function graph options if function graph is configured.
1190  */
1191 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1192 # define FGRAPH_FLAGS						\
1193 		C(DISPLAY_GRAPH,	"display-graph"),
1194 #else
1195 # define FGRAPH_FLAGS
1196 #endif
1197 
1198 #ifdef CONFIG_BRANCH_TRACER
1199 # define BRANCH_FLAGS					\
1200 		C(BRANCH,		"branch"),
1201 #else
1202 # define BRANCH_FLAGS
1203 #endif
1204 
1205 #ifdef CONFIG_FUNCTION_TRACER
1206 # define FUNCTION_FLAGS						\
1207 		C(FUNCTION,		"function-trace"),	\
1208 		C(FUNC_FORK,		"function-fork"),
1209 # define FUNCTION_DEFAULT_FLAGS		TRACE_ITER_FUNCTION
1210 #else
1211 # define FUNCTION_FLAGS
1212 # define FUNCTION_DEFAULT_FLAGS		0UL
1213 # define TRACE_ITER_FUNC_FORK		0UL
1214 #endif
1215 
1216 #ifdef CONFIG_STACKTRACE
1217 # define STACK_FLAGS				\
1218 		C(STACKTRACE,		"stacktrace"),
1219 #else
1220 # define STACK_FLAGS
1221 #endif
1222 
1223 /*
1224  * trace_iterator_flags is an enumeration that defines bit
1225  * positions into trace_flags that controls the output.
1226  *
1227  * NOTE: These bits must match the trace_options array in
1228  *       trace.c (this macro guarantees it).
1229  */
1230 #define TRACE_FLAGS						\
1231 		C(PRINT_PARENT,		"print-parent"),	\
1232 		C(SYM_OFFSET,		"sym-offset"),		\
1233 		C(SYM_ADDR,		"sym-addr"),		\
1234 		C(VERBOSE,		"verbose"),		\
1235 		C(RAW,			"raw"),			\
1236 		C(HEX,			"hex"),			\
1237 		C(BIN,			"bin"),			\
1238 		C(BLOCK,		"block"),		\
1239 		C(FIELDS,		"fields"),		\
1240 		C(PRINTK,		"trace_printk"),	\
1241 		C(ANNOTATE,		"annotate"),		\
1242 		C(USERSTACKTRACE,	"userstacktrace"),	\
1243 		C(SYM_USEROBJ,		"sym-userobj"),		\
1244 		C(PRINTK_MSGONLY,	"printk-msg-only"),	\
1245 		C(CONTEXT_INFO,		"context-info"),   /* Print pid/cpu/time */ \
1246 		C(LATENCY_FMT,		"latency-format"),	\
1247 		C(RECORD_CMD,		"record-cmd"),		\
1248 		C(RECORD_TGID,		"record-tgid"),		\
1249 		C(OVERWRITE,		"overwrite"),		\
1250 		C(STOP_ON_FREE,		"disable_on_free"),	\
1251 		C(IRQ_INFO,		"irq-info"),		\
1252 		C(MARKERS,		"markers"),		\
1253 		C(EVENT_FORK,		"event-fork"),		\
1254 		C(PAUSE_ON_TRACE,	"pause-on-trace"),	\
1255 		C(HASH_PTR,		"hash-ptr"),	/* Print hashed pointer */ \
1256 		FUNCTION_FLAGS					\
1257 		FGRAPH_FLAGS					\
1258 		STACK_FLAGS					\
1259 		BRANCH_FLAGS
1260 
1261 /*
1262  * By defining C, we can make TRACE_FLAGS a list of bit names
1263  * that will define the bits for the flag masks.
1264  */
1265 #undef C
1266 #define C(a, b) TRACE_ITER_##a##_BIT
1267 
1268 enum trace_iterator_bits {
1269 	TRACE_FLAGS
1270 	/* Make sure we don't go more than we have bits for */
1271 	TRACE_ITER_LAST_BIT
1272 };
1273 
1274 /*
1275  * By redefining C, we can make TRACE_FLAGS a list of masks that
1276  * use the bits as defined above.
1277  */
1278 #undef C
1279 #define C(a, b) TRACE_ITER_##a = (1 << TRACE_ITER_##a##_BIT)
1280 
1281 enum trace_iterator_flags { TRACE_FLAGS };
1282 
1283 /*
1284  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
1285  * control the output of kernel symbols.
1286  */
1287 #define TRACE_ITER_SYM_MASK \
1288 	(TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
1289 
1290 extern struct tracer nop_trace;
1291 
1292 #ifdef CONFIG_BRANCH_TRACER
1293 extern int enable_branch_tracing(struct trace_array *tr);
1294 extern void disable_branch_tracing(void);
1295 static inline int trace_branch_enable(struct trace_array *tr)
1296 {
1297 	if (tr->trace_flags & TRACE_ITER_BRANCH)
1298 		return enable_branch_tracing(tr);
1299 	return 0;
1300 }
1301 static inline void trace_branch_disable(void)
1302 {
1303 	/* due to races, always disable */
1304 	disable_branch_tracing();
1305 }
1306 #else
1307 static inline int trace_branch_enable(struct trace_array *tr)
1308 {
1309 	return 0;
1310 }
1311 static inline void trace_branch_disable(void)
1312 {
1313 }
1314 #endif /* CONFIG_BRANCH_TRACER */
1315 
1316 /* set ring buffers to default size if not already done so */
1317 int tracing_update_buffers(struct trace_array *tr);
1318 
1319 union trace_synth_field {
1320 	u8				as_u8;
1321 	u16				as_u16;
1322 	u32				as_u32;
1323 	u64				as_u64;
1324 	struct trace_dynamic_info	as_dynamic;
1325 };
1326 
1327 struct ftrace_event_field {
1328 	struct list_head	link;
1329 	const char		*name;
1330 	const char		*type;
1331 	int			filter_type;
1332 	int			offset;
1333 	int			size;
1334 	int			is_signed;
1335 	int			len;
1336 };
1337 
1338 struct prog_entry;
1339 
1340 struct event_filter {
1341 	struct prog_entry __rcu	*prog;
1342 	char			*filter_string;
1343 };
1344 
1345 struct event_subsystem {
1346 	struct list_head	list;
1347 	const char		*name;
1348 	struct event_filter	*filter;
1349 	int			ref_count;
1350 };
1351 
1352 struct trace_subsystem_dir {
1353 	struct list_head		list;
1354 	struct event_subsystem		*subsystem;
1355 	struct trace_array		*tr;
1356 	struct eventfs_inode		*ei;
1357 	int				ref_count;
1358 	int				nr_events;
1359 };
1360 
1361 extern int call_filter_check_discard(struct trace_event_call *call, void *rec,
1362 				     struct trace_buffer *buffer,
1363 				     struct ring_buffer_event *event);
1364 
1365 void trace_buffer_unlock_commit_regs(struct trace_array *tr,
1366 				     struct trace_buffer *buffer,
1367 				     struct ring_buffer_event *event,
1368 				     unsigned int trcace_ctx,
1369 				     struct pt_regs *regs);
1370 
1371 static inline void trace_buffer_unlock_commit(struct trace_array *tr,
1372 					      struct trace_buffer *buffer,
1373 					      struct ring_buffer_event *event,
1374 					      unsigned int trace_ctx)
1375 {
1376 	trace_buffer_unlock_commit_regs(tr, buffer, event, trace_ctx, NULL);
1377 }
1378 
1379 DECLARE_PER_CPU(bool, trace_taskinfo_save);
1380 int trace_save_cmdline(struct task_struct *tsk);
1381 int trace_create_savedcmd(void);
1382 int trace_alloc_tgid_map(void);
1383 void trace_free_saved_cmdlines_buffer(void);
1384 
1385 extern const struct file_operations tracing_saved_cmdlines_fops;
1386 extern const struct file_operations tracing_saved_tgids_fops;
1387 extern const struct file_operations tracing_saved_cmdlines_size_fops;
1388 
1389 DECLARE_PER_CPU(struct ring_buffer_event *, trace_buffered_event);
1390 DECLARE_PER_CPU(int, trace_buffered_event_cnt);
1391 void trace_buffered_event_disable(void);
1392 void trace_buffered_event_enable(void);
1393 
1394 void early_enable_events(struct trace_array *tr, char *buf, bool disable_first);
1395 
1396 static inline void
1397 __trace_event_discard_commit(struct trace_buffer *buffer,
1398 			     struct ring_buffer_event *event)
1399 {
1400 	if (this_cpu_read(trace_buffered_event) == event) {
1401 		/* Simply release the temp buffer and enable preemption */
1402 		this_cpu_dec(trace_buffered_event_cnt);
1403 		preempt_enable_notrace();
1404 		return;
1405 	}
1406 	/* ring_buffer_discard_commit() enables preemption */
1407 	ring_buffer_discard_commit(buffer, event);
1408 }
1409 
1410 /*
1411  * Helper function for event_trigger_unlock_commit{_regs}().
1412  * If there are event triggers attached to this event that requires
1413  * filtering against its fields, then they will be called as the
1414  * entry already holds the field information of the current event.
1415  *
1416  * It also checks if the event should be discarded or not.
1417  * It is to be discarded if the event is soft disabled and the
1418  * event was only recorded to process triggers, or if the event
1419  * filter is active and this event did not match the filters.
1420  *
1421  * Returns true if the event is discarded, false otherwise.
1422  */
1423 static inline bool
1424 __event_trigger_test_discard(struct trace_event_file *file,
1425 			     struct trace_buffer *buffer,
1426 			     struct ring_buffer_event *event,
1427 			     void *entry,
1428 			     enum event_trigger_type *tt)
1429 {
1430 	unsigned long eflags = file->flags;
1431 
1432 	if (eflags & EVENT_FILE_FL_TRIGGER_COND)
1433 		*tt = event_triggers_call(file, buffer, entry, event);
1434 
1435 	if (likely(!(file->flags & (EVENT_FILE_FL_SOFT_DISABLED |
1436 				    EVENT_FILE_FL_FILTERED |
1437 				    EVENT_FILE_FL_PID_FILTER))))
1438 		return false;
1439 
1440 	if (file->flags & EVENT_FILE_FL_SOFT_DISABLED)
1441 		goto discard;
1442 
1443 	if (file->flags & EVENT_FILE_FL_FILTERED &&
1444 	    !filter_match_preds(file->filter, entry))
1445 		goto discard;
1446 
1447 	if ((file->flags & EVENT_FILE_FL_PID_FILTER) &&
1448 	    trace_event_ignore_this_pid(file))
1449 		goto discard;
1450 
1451 	return false;
1452  discard:
1453 	__trace_event_discard_commit(buffer, event);
1454 	return true;
1455 }
1456 
1457 /**
1458  * event_trigger_unlock_commit - handle triggers and finish event commit
1459  * @file: The file pointer associated with the event
1460  * @buffer: The ring buffer that the event is being written to
1461  * @event: The event meta data in the ring buffer
1462  * @entry: The event itself
1463  * @trace_ctx: The tracing context flags.
1464  *
1465  * This is a helper function to handle triggers that require data
1466  * from the event itself. It also tests the event against filters and
1467  * if the event is soft disabled and should be discarded.
1468  */
1469 static inline void
1470 event_trigger_unlock_commit(struct trace_event_file *file,
1471 			    struct trace_buffer *buffer,
1472 			    struct ring_buffer_event *event,
1473 			    void *entry, unsigned int trace_ctx)
1474 {
1475 	enum event_trigger_type tt = ETT_NONE;
1476 
1477 	if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1478 		trace_buffer_unlock_commit(file->tr, buffer, event, trace_ctx);
1479 
1480 	if (tt)
1481 		event_triggers_post_call(file, tt);
1482 }
1483 
1484 #define FILTER_PRED_INVALID	((unsigned short)-1)
1485 #define FILTER_PRED_IS_RIGHT	(1 << 15)
1486 #define FILTER_PRED_FOLD	(1 << 15)
1487 
1488 /*
1489  * The max preds is the size of unsigned short with
1490  * two flags at the MSBs. One bit is used for both the IS_RIGHT
1491  * and FOLD flags. The other is reserved.
1492  *
1493  * 2^14 preds is way more than enough.
1494  */
1495 #define MAX_FILTER_PRED		16384
1496 
1497 struct filter_pred;
1498 struct regex;
1499 
1500 typedef int (*regex_match_func)(char *str, struct regex *r, int len);
1501 
1502 enum regex_type {
1503 	MATCH_FULL = 0,
1504 	MATCH_FRONT_ONLY,
1505 	MATCH_MIDDLE_ONLY,
1506 	MATCH_END_ONLY,
1507 	MATCH_GLOB,
1508 	MATCH_INDEX,
1509 };
1510 
1511 struct regex {
1512 	char			pattern[MAX_FILTER_STR_VAL];
1513 	int			len;
1514 	int			field_len;
1515 	regex_match_func	match;
1516 };
1517 
1518 static inline bool is_string_field(struct ftrace_event_field *field)
1519 {
1520 	return field->filter_type == FILTER_DYN_STRING ||
1521 	       field->filter_type == FILTER_RDYN_STRING ||
1522 	       field->filter_type == FILTER_STATIC_STRING ||
1523 	       field->filter_type == FILTER_PTR_STRING ||
1524 	       field->filter_type == FILTER_COMM;
1525 }
1526 
1527 static inline bool is_function_field(struct ftrace_event_field *field)
1528 {
1529 	return field->filter_type == FILTER_TRACE_FN;
1530 }
1531 
1532 extern enum regex_type
1533 filter_parse_regex(char *buff, int len, char **search, int *not);
1534 extern void print_event_filter(struct trace_event_file *file,
1535 			       struct trace_seq *s);
1536 extern int apply_event_filter(struct trace_event_file *file,
1537 			      char *filter_string);
1538 extern int apply_subsystem_event_filter(struct trace_subsystem_dir *dir,
1539 					char *filter_string);
1540 extern void print_subsystem_event_filter(struct event_subsystem *system,
1541 					 struct trace_seq *s);
1542 extern int filter_assign_type(const char *type);
1543 extern int create_event_filter(struct trace_array *tr,
1544 			       struct trace_event_call *call,
1545 			       char *filter_str, bool set_str,
1546 			       struct event_filter **filterp);
1547 extern void free_event_filter(struct event_filter *filter);
1548 
1549 struct ftrace_event_field *
1550 trace_find_event_field(struct trace_event_call *call, char *name);
1551 
1552 extern void trace_event_enable_cmd_record(bool enable);
1553 extern void trace_event_enable_tgid_record(bool enable);
1554 
1555 extern int event_trace_init(void);
1556 extern int init_events(void);
1557 extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
1558 extern int event_trace_del_tracer(struct trace_array *tr);
1559 extern void __trace_early_add_events(struct trace_array *tr);
1560 
1561 extern struct trace_event_file *__find_event_file(struct trace_array *tr,
1562 						  const char *system,
1563 						  const char *event);
1564 extern struct trace_event_file *find_event_file(struct trace_array *tr,
1565 						const char *system,
1566 						const char *event);
1567 
1568 static inline void *event_file_data(struct file *filp)
1569 {
1570 	return READ_ONCE(file_inode(filp)->i_private);
1571 }
1572 
1573 extern struct mutex event_mutex;
1574 extern struct list_head ftrace_events;
1575 
1576 extern const struct file_operations event_trigger_fops;
1577 extern const struct file_operations event_hist_fops;
1578 extern const struct file_operations event_hist_debug_fops;
1579 extern const struct file_operations event_inject_fops;
1580 
1581 #ifdef CONFIG_HIST_TRIGGERS
1582 extern int register_trigger_hist_cmd(void);
1583 extern int register_trigger_hist_enable_disable_cmds(void);
1584 #else
1585 static inline int register_trigger_hist_cmd(void) { return 0; }
1586 static inline int register_trigger_hist_enable_disable_cmds(void) { return 0; }
1587 #endif
1588 
1589 extern int register_trigger_cmds(void);
1590 extern void clear_event_triggers(struct trace_array *tr);
1591 
1592 enum {
1593 	EVENT_TRIGGER_FL_PROBE		= BIT(0),
1594 };
1595 
1596 struct event_trigger_data {
1597 	unsigned long			count;
1598 	int				ref;
1599 	int				flags;
1600 	struct event_trigger_ops	*ops;
1601 	struct event_command		*cmd_ops;
1602 	struct event_filter __rcu	*filter;
1603 	char				*filter_str;
1604 	void				*private_data;
1605 	bool				paused;
1606 	bool				paused_tmp;
1607 	struct list_head		list;
1608 	char				*name;
1609 	struct list_head		named_list;
1610 	struct event_trigger_data	*named_data;
1611 };
1612 
1613 /* Avoid typos */
1614 #define ENABLE_EVENT_STR	"enable_event"
1615 #define DISABLE_EVENT_STR	"disable_event"
1616 #define ENABLE_HIST_STR		"enable_hist"
1617 #define DISABLE_HIST_STR	"disable_hist"
1618 
1619 struct enable_trigger_data {
1620 	struct trace_event_file		*file;
1621 	bool				enable;
1622 	bool				hist;
1623 };
1624 
1625 extern int event_enable_trigger_print(struct seq_file *m,
1626 				      struct event_trigger_data *data);
1627 extern void event_enable_trigger_free(struct event_trigger_data *data);
1628 extern int event_enable_trigger_parse(struct event_command *cmd_ops,
1629 				      struct trace_event_file *file,
1630 				      char *glob, char *cmd,
1631 				      char *param_and_filter);
1632 extern int event_enable_register_trigger(char *glob,
1633 					 struct event_trigger_data *data,
1634 					 struct trace_event_file *file);
1635 extern void event_enable_unregister_trigger(char *glob,
1636 					    struct event_trigger_data *test,
1637 					    struct trace_event_file *file);
1638 extern void trigger_data_free(struct event_trigger_data *data);
1639 extern int event_trigger_init(struct event_trigger_data *data);
1640 extern int trace_event_trigger_enable_disable(struct trace_event_file *file,
1641 					      int trigger_enable);
1642 extern void update_cond_flag(struct trace_event_file *file);
1643 extern int set_trigger_filter(char *filter_str,
1644 			      struct event_trigger_data *trigger_data,
1645 			      struct trace_event_file *file);
1646 extern struct event_trigger_data *find_named_trigger(const char *name);
1647 extern bool is_named_trigger(struct event_trigger_data *test);
1648 extern int save_named_trigger(const char *name,
1649 			      struct event_trigger_data *data);
1650 extern void del_named_trigger(struct event_trigger_data *data);
1651 extern void pause_named_trigger(struct event_trigger_data *data);
1652 extern void unpause_named_trigger(struct event_trigger_data *data);
1653 extern void set_named_trigger_data(struct event_trigger_data *data,
1654 				   struct event_trigger_data *named_data);
1655 extern struct event_trigger_data *
1656 get_named_trigger_data(struct event_trigger_data *data);
1657 extern int register_event_command(struct event_command *cmd);
1658 extern int unregister_event_command(struct event_command *cmd);
1659 extern int register_trigger_hist_enable_disable_cmds(void);
1660 extern bool event_trigger_check_remove(const char *glob);
1661 extern bool event_trigger_empty_param(const char *param);
1662 extern int event_trigger_separate_filter(char *param_and_filter, char **param,
1663 					 char **filter, bool param_required);
1664 extern struct event_trigger_data *
1665 event_trigger_alloc(struct event_command *cmd_ops,
1666 		    char *cmd,
1667 		    char *param,
1668 		    void *private_data);
1669 extern int event_trigger_parse_num(char *trigger,
1670 				   struct event_trigger_data *trigger_data);
1671 extern int event_trigger_set_filter(struct event_command *cmd_ops,
1672 				    struct trace_event_file *file,
1673 				    char *param,
1674 				    struct event_trigger_data *trigger_data);
1675 extern void event_trigger_reset_filter(struct event_command *cmd_ops,
1676 				       struct event_trigger_data *trigger_data);
1677 extern int event_trigger_register(struct event_command *cmd_ops,
1678 				  struct trace_event_file *file,
1679 				  char *glob,
1680 				  struct event_trigger_data *trigger_data);
1681 extern void event_trigger_unregister(struct event_command *cmd_ops,
1682 				     struct trace_event_file *file,
1683 				     char *glob,
1684 				     struct event_trigger_data *trigger_data);
1685 
1686 extern void event_file_get(struct trace_event_file *file);
1687 extern void event_file_put(struct trace_event_file *file);
1688 
1689 /**
1690  * struct event_trigger_ops - callbacks for trace event triggers
1691  *
1692  * The methods in this structure provide per-event trigger hooks for
1693  * various trigger operations.
1694  *
1695  * The @init and @free methods are used during trigger setup and
1696  * teardown, typically called from an event_command's @parse()
1697  * function implementation.
1698  *
1699  * The @print method is used to print the trigger spec.
1700  *
1701  * The @trigger method is the function that actually implements the
1702  * trigger and is called in the context of the triggering event
1703  * whenever that event occurs.
1704  *
1705  * All the methods below, except for @init() and @free(), must be
1706  * implemented.
1707  *
1708  * @trigger: The trigger 'probe' function called when the triggering
1709  *	event occurs.  The data passed into this callback is the data
1710  *	that was supplied to the event_command @reg() function that
1711  *	registered the trigger (see struct event_command) along with
1712  *	the trace record, rec.
1713  *
1714  * @init: An optional initialization function called for the trigger
1715  *	when the trigger is registered (via the event_command reg()
1716  *	function).  This can be used to perform per-trigger
1717  *	initialization such as incrementing a per-trigger reference
1718  *	count, for instance.  This is usually implemented by the
1719  *	generic utility function @event_trigger_init() (see
1720  *	trace_event_triggers.c).
1721  *
1722  * @free: An optional de-initialization function called for the
1723  *	trigger when the trigger is unregistered (via the
1724  *	event_command @reg() function).  This can be used to perform
1725  *	per-trigger de-initialization such as decrementing a
1726  *	per-trigger reference count and freeing corresponding trigger
1727  *	data, for instance.  This is usually implemented by the
1728  *	generic utility function @event_trigger_free() (see
1729  *	trace_event_triggers.c).
1730  *
1731  * @print: The callback function invoked to have the trigger print
1732  *	itself.  This is usually implemented by a wrapper function
1733  *	that calls the generic utility function @event_trigger_print()
1734  *	(see trace_event_triggers.c).
1735  */
1736 struct event_trigger_ops {
1737 	void			(*trigger)(struct event_trigger_data *data,
1738 					   struct trace_buffer *buffer,
1739 					   void *rec,
1740 					   struct ring_buffer_event *rbe);
1741 	int			(*init)(struct event_trigger_data *data);
1742 	void			(*free)(struct event_trigger_data *data);
1743 	int			(*print)(struct seq_file *m,
1744 					 struct event_trigger_data *data);
1745 };
1746 
1747 /**
1748  * struct event_command - callbacks and data members for event commands
1749  *
1750  * Event commands are invoked by users by writing the command name
1751  * into the 'trigger' file associated with a trace event.  The
1752  * parameters associated with a specific invocation of an event
1753  * command are used to create an event trigger instance, which is
1754  * added to the list of trigger instances associated with that trace
1755  * event.  When the event is hit, the set of triggers associated with
1756  * that event is invoked.
1757  *
1758  * The data members in this structure provide per-event command data
1759  * for various event commands.
1760  *
1761  * All the data members below, except for @post_trigger, must be set
1762  * for each event command.
1763  *
1764  * @name: The unique name that identifies the event command.  This is
1765  *	the name used when setting triggers via trigger files.
1766  *
1767  * @trigger_type: A unique id that identifies the event command
1768  *	'type'.  This value has two purposes, the first to ensure that
1769  *	only one trigger of the same type can be set at a given time
1770  *	for a particular event e.g. it doesn't make sense to have both
1771  *	a traceon and traceoff trigger attached to a single event at
1772  *	the same time, so traceon and traceoff have the same type
1773  *	though they have different names.  The @trigger_type value is
1774  *	also used as a bit value for deferring the actual trigger
1775  *	action until after the current event is finished.  Some
1776  *	commands need to do this if they themselves log to the trace
1777  *	buffer (see the @post_trigger() member below).  @trigger_type
1778  *	values are defined by adding new values to the trigger_type
1779  *	enum in include/linux/trace_events.h.
1780  *
1781  * @flags: See the enum event_command_flags below.
1782  *
1783  * All the methods below, except for @set_filter() and @unreg_all(),
1784  * must be implemented.
1785  *
1786  * @parse: The callback function responsible for parsing and
1787  *	registering the trigger written to the 'trigger' file by the
1788  *	user.  It allocates the trigger instance and registers it with
1789  *	the appropriate trace event.  It makes use of the other
1790  *	event_command callback functions to orchestrate this, and is
1791  *	usually implemented by the generic utility function
1792  *	@event_trigger_callback() (see trace_event_triggers.c).
1793  *
1794  * @reg: Adds the trigger to the list of triggers associated with the
1795  *	event, and enables the event trigger itself, after
1796  *	initializing it (via the event_trigger_ops @init() function).
1797  *	This is also where commands can use the @trigger_type value to
1798  *	make the decision as to whether or not multiple instances of
1799  *	the trigger should be allowed.  This is usually implemented by
1800  *	the generic utility function @register_trigger() (see
1801  *	trace_event_triggers.c).
1802  *
1803  * @unreg: Removes the trigger from the list of triggers associated
1804  *	with the event, and disables the event trigger itself, after
1805  *	initializing it (via the event_trigger_ops @free() function).
1806  *	This is usually implemented by the generic utility function
1807  *	@unregister_trigger() (see trace_event_triggers.c).
1808  *
1809  * @unreg_all: An optional function called to remove all the triggers
1810  *	from the list of triggers associated with the event.  Called
1811  *	when a trigger file is opened in truncate mode.
1812  *
1813  * @set_filter: An optional function called to parse and set a filter
1814  *	for the trigger.  If no @set_filter() method is set for the
1815  *	event command, filters set by the user for the command will be
1816  *	ignored.  This is usually implemented by the generic utility
1817  *	function @set_trigger_filter() (see trace_event_triggers.c).
1818  *
1819  * @get_trigger_ops: The callback function invoked to retrieve the
1820  *	event_trigger_ops implementation associated with the command.
1821  *	This callback function allows a single event_command to
1822  *	support multiple trigger implementations via different sets of
1823  *	event_trigger_ops, depending on the value of the @param
1824  *	string.
1825  */
1826 struct event_command {
1827 	struct list_head	list;
1828 	char			*name;
1829 	enum event_trigger_type	trigger_type;
1830 	int			flags;
1831 	int			(*parse)(struct event_command *cmd_ops,
1832 					 struct trace_event_file *file,
1833 					 char *glob, char *cmd,
1834 					 char *param_and_filter);
1835 	int			(*reg)(char *glob,
1836 				       struct event_trigger_data *data,
1837 				       struct trace_event_file *file);
1838 	void			(*unreg)(char *glob,
1839 					 struct event_trigger_data *data,
1840 					 struct trace_event_file *file);
1841 	void			(*unreg_all)(struct trace_event_file *file);
1842 	int			(*set_filter)(char *filter_str,
1843 					      struct event_trigger_data *data,
1844 					      struct trace_event_file *file);
1845 	struct event_trigger_ops *(*get_trigger_ops)(char *cmd, char *param);
1846 };
1847 
1848 /**
1849  * enum event_command_flags - flags for struct event_command
1850  *
1851  * @POST_TRIGGER: A flag that says whether or not this command needs
1852  *	to have its action delayed until after the current event has
1853  *	been closed.  Some triggers need to avoid being invoked while
1854  *	an event is currently in the process of being logged, since
1855  *	the trigger may itself log data into the trace buffer.  Thus
1856  *	we make sure the current event is committed before invoking
1857  *	those triggers.  To do that, the trigger invocation is split
1858  *	in two - the first part checks the filter using the current
1859  *	trace record; if a command has the @post_trigger flag set, it
1860  *	sets a bit for itself in the return value, otherwise it
1861  *	directly invokes the trigger.  Once all commands have been
1862  *	either invoked or set their return flag, the current record is
1863  *	either committed or discarded.  At that point, if any commands
1864  *	have deferred their triggers, those commands are finally
1865  *	invoked following the close of the current event.  In other
1866  *	words, if the event_trigger_ops @func() probe implementation
1867  *	itself logs to the trace buffer, this flag should be set,
1868  *	otherwise it can be left unspecified.
1869  *
1870  * @NEEDS_REC: A flag that says whether or not this command needs
1871  *	access to the trace record in order to perform its function,
1872  *	regardless of whether or not it has a filter associated with
1873  *	it (filters make a trigger require access to the trace record
1874  *	but are not always present).
1875  */
1876 enum event_command_flags {
1877 	EVENT_CMD_FL_POST_TRIGGER	= 1,
1878 	EVENT_CMD_FL_NEEDS_REC		= 2,
1879 };
1880 
1881 static inline bool event_command_post_trigger(struct event_command *cmd_ops)
1882 {
1883 	return cmd_ops->flags & EVENT_CMD_FL_POST_TRIGGER;
1884 }
1885 
1886 static inline bool event_command_needs_rec(struct event_command *cmd_ops)
1887 {
1888 	return cmd_ops->flags & EVENT_CMD_FL_NEEDS_REC;
1889 }
1890 
1891 extern int trace_event_enable_disable(struct trace_event_file *file,
1892 				      int enable, int soft_disable);
1893 extern int tracing_alloc_snapshot(void);
1894 extern void tracing_snapshot_cond(struct trace_array *tr, void *cond_data);
1895 extern int tracing_snapshot_cond_enable(struct trace_array *tr, void *cond_data, cond_update_fn_t update);
1896 
1897 extern int tracing_snapshot_cond_disable(struct trace_array *tr);
1898 extern void *tracing_cond_snapshot_data(struct trace_array *tr);
1899 
1900 extern const char *__start___trace_bprintk_fmt[];
1901 extern const char *__stop___trace_bprintk_fmt[];
1902 
1903 extern const char *__start___tracepoint_str[];
1904 extern const char *__stop___tracepoint_str[];
1905 
1906 void trace_printk_control(bool enabled);
1907 void trace_printk_start_comm(void);
1908 int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set);
1909 int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled);
1910 
1911 /* Used from boot time tracer */
1912 extern int trace_set_options(struct trace_array *tr, char *option);
1913 extern int tracing_set_tracer(struct trace_array *tr, const char *buf);
1914 extern ssize_t tracing_resize_ring_buffer(struct trace_array *tr,
1915 					  unsigned long size, int cpu_id);
1916 extern int tracing_set_cpumask(struct trace_array *tr,
1917 				cpumask_var_t tracing_cpumask_new);
1918 
1919 
1920 #define MAX_EVENT_NAME_LEN	64
1921 
1922 extern ssize_t trace_parse_run_command(struct file *file,
1923 		const char __user *buffer, size_t count, loff_t *ppos,
1924 		int (*createfn)(const char *));
1925 
1926 extern unsigned int err_pos(char *cmd, const char *str);
1927 extern void tracing_log_err(struct trace_array *tr,
1928 			    const char *loc, const char *cmd,
1929 			    const char **errs, u8 type, u16 pos);
1930 
1931 /*
1932  * Normal trace_printk() and friends allocates special buffers
1933  * to do the manipulation, as well as saves the print formats
1934  * into sections to display. But the trace infrastructure wants
1935  * to use these without the added overhead at the price of being
1936  * a bit slower (used mainly for warnings, where we don't care
1937  * about performance). The internal_trace_puts() is for such
1938  * a purpose.
1939  */
1940 #define internal_trace_puts(str) __trace_puts(_THIS_IP_, str, strlen(str))
1941 
1942 #undef FTRACE_ENTRY
1943 #define FTRACE_ENTRY(call, struct_name, id, tstruct, print)	\
1944 	extern struct trace_event_call					\
1945 	__aligned(4) event_##call;
1946 #undef FTRACE_ENTRY_DUP
1947 #define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print)	\
1948 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
1949 #undef FTRACE_ENTRY_PACKED
1950 #define FTRACE_ENTRY_PACKED(call, struct_name, id, tstruct, print) \
1951 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
1952 
1953 #include "trace_entries.h"
1954 
1955 #if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_FUNCTION_TRACER)
1956 int perf_ftrace_event_register(struct trace_event_call *call,
1957 			       enum trace_reg type, void *data);
1958 #else
1959 #define perf_ftrace_event_register NULL
1960 #endif
1961 
1962 #ifdef CONFIG_FTRACE_SYSCALLS
1963 void init_ftrace_syscalls(void);
1964 const char *get_syscall_name(int syscall);
1965 #else
1966 static inline void init_ftrace_syscalls(void) { }
1967 static inline const char *get_syscall_name(int syscall)
1968 {
1969 	return NULL;
1970 }
1971 #endif
1972 
1973 #ifdef CONFIG_EVENT_TRACING
1974 void trace_event_init(void);
1975 void trace_event_eval_update(struct trace_eval_map **map, int len);
1976 /* Used from boot time tracer */
1977 extern int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set);
1978 extern int trigger_process_regex(struct trace_event_file *file, char *buff);
1979 #else
1980 static inline void __init trace_event_init(void) { }
1981 static inline void trace_event_eval_update(struct trace_eval_map **map, int len) { }
1982 #endif
1983 
1984 #ifdef CONFIG_TRACER_SNAPSHOT
1985 void tracing_snapshot_instance(struct trace_array *tr);
1986 int tracing_alloc_snapshot_instance(struct trace_array *tr);
1987 int tracing_arm_snapshot(struct trace_array *tr);
1988 void tracing_disarm_snapshot(struct trace_array *tr);
1989 #else
1990 static inline void tracing_snapshot_instance(struct trace_array *tr) { }
1991 static inline int tracing_alloc_snapshot_instance(struct trace_array *tr)
1992 {
1993 	return 0;
1994 }
1995 static inline int tracing_arm_snapshot(struct trace_array *tr) { return 0; }
1996 static inline void tracing_disarm_snapshot(struct trace_array *tr) { }
1997 #endif
1998 
1999 #ifdef CONFIG_PREEMPT_TRACER
2000 void tracer_preempt_on(unsigned long a0, unsigned long a1);
2001 void tracer_preempt_off(unsigned long a0, unsigned long a1);
2002 #else
2003 static inline void tracer_preempt_on(unsigned long a0, unsigned long a1) { }
2004 static inline void tracer_preempt_off(unsigned long a0, unsigned long a1) { }
2005 #endif
2006 #ifdef CONFIG_IRQSOFF_TRACER
2007 void tracer_hardirqs_on(unsigned long a0, unsigned long a1);
2008 void tracer_hardirqs_off(unsigned long a0, unsigned long a1);
2009 #else
2010 static inline void tracer_hardirqs_on(unsigned long a0, unsigned long a1) { }
2011 static inline void tracer_hardirqs_off(unsigned long a0, unsigned long a1) { }
2012 #endif
2013 
2014 /*
2015  * Reset the state of the trace_iterator so that it can read consumed data.
2016  * Normally, the trace_iterator is used for reading the data when it is not
2017  * consumed, and must retain state.
2018  */
2019 static __always_inline void trace_iterator_reset(struct trace_iterator *iter)
2020 {
2021 	memset_startat(iter, 0, seq);
2022 	iter->pos = -1;
2023 }
2024 
2025 /* Check the name is good for event/group/fields */
2026 static inline bool __is_good_name(const char *name, bool hash_ok)
2027 {
2028 	if (!isalpha(*name) && *name != '_' && (!hash_ok || *name != '-'))
2029 		return false;
2030 	while (*++name != '\0') {
2031 		if (!isalpha(*name) && !isdigit(*name) && *name != '_' &&
2032 		    (!hash_ok || *name != '-'))
2033 			return false;
2034 	}
2035 	return true;
2036 }
2037 
2038 /* Check the name is good for event/group/fields */
2039 static inline bool is_good_name(const char *name)
2040 {
2041 	return __is_good_name(name, false);
2042 }
2043 
2044 /* Check the name is good for system */
2045 static inline bool is_good_system_name(const char *name)
2046 {
2047 	return __is_good_name(name, true);
2048 }
2049 
2050 /* Convert certain expected symbols into '_' when generating event names */
2051 static inline void sanitize_event_name(char *name)
2052 {
2053 	while (*name++ != '\0')
2054 		if (*name == ':' || *name == '.')
2055 			*name = '_';
2056 }
2057 
2058 /*
2059  * This is a generic way to read and write a u64 value from a file in tracefs.
2060  *
2061  * The value is stored on the variable pointed by *val. The value needs
2062  * to be at least *min and at most *max. The write is protected by an
2063  * existing *lock.
2064  */
2065 struct trace_min_max_param {
2066 	struct mutex	*lock;
2067 	u64		*val;
2068 	u64		*min;
2069 	u64		*max;
2070 };
2071 
2072 #define U64_STR_SIZE		24	/* 20 digits max */
2073 
2074 extern const struct file_operations trace_min_max_fops;
2075 
2076 #ifdef CONFIG_RV
2077 extern int rv_init_interface(void);
2078 #else
2079 static inline int rv_init_interface(void)
2080 {
2081 	return 0;
2082 }
2083 #endif
2084 
2085 #endif /* _LINUX_KERNEL_TRACE_H */
2086