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