xref: /linux/kernel/trace/trace.h (revision 6cb0bd94c08e37236f7ba2ff474c1e70c8318484)
1 // SPDX-License-Identifier: GPL-2.0
2 
3 #ifndef _LINUX_KERNEL_TRACE_H
4 #define _LINUX_KERNEL_TRACE_H
5 
6 #include <linux/fs.h>
7 #include <linux/atomic.h>
8 #include <linux/sched.h>
9 #include <linux/clocksource.h>
10 #include <linux/ring_buffer.h>
11 #include <linux/mmiotrace.h>
12 #include <linux/tracepoint.h>
13 #include <linux/ftrace.h>
14 #include <linux/trace.h>
15 #include <linux/hw_breakpoint.h>
16 #include <linux/trace_seq.h>
17 #include <linux/trace_events.h>
18 #include <linux/compiler.h>
19 #include <linux/glob.h>
20 #include <linux/irq_work.h>
21 #include <linux/workqueue.h>
22 #include <linux/ctype.h>
23 #include <linux/once_lite.h>
24 #include <linux/ftrace_regs.h>
25 
26 #include "pid_list.h"
27 
28 #ifdef CONFIG_FTRACE_SYSCALLS
29 #include <asm/unistd.h>		/* For NR_syscalls	     */
30 #include <asm/syscall.h>	/* some archs define it here */
31 #endif
32 
33 #define TRACE_MODE_WRITE	0640
34 #define TRACE_MODE_READ		0440
35 
36 enum trace_type {
37 	__TRACE_FIRST_TYPE = 0,
38 
39 	TRACE_FN,
40 	TRACE_CTX,
41 	TRACE_WAKE,
42 	TRACE_STACK,
43 	TRACE_PRINT,
44 	TRACE_BPRINT,
45 	TRACE_MMIO_RW,
46 	TRACE_MMIO_MAP,
47 	TRACE_BRANCH,
48 	TRACE_GRAPH_RET,
49 	TRACE_GRAPH_ENT,
50 	TRACE_GRAPH_RETADDR_ENT,
51 	TRACE_USER_STACK,
52 	TRACE_BLK,
53 	TRACE_BPUTS,
54 	TRACE_HWLAT,
55 	TRACE_OSNOISE,
56 	TRACE_TIMERLAT,
57 	TRACE_RAW_DATA,
58 	TRACE_FUNC_REPEATS,
59 
60 	__TRACE_LAST_TYPE,
61 };
62 
63 
64 #undef __field
65 #define __field(type, item)		type	item;
66 
67 #undef __field_fn
68 #define __field_fn(type, item)		type	item;
69 
70 #undef __field_struct
71 #define __field_struct(type, item)	__field(type, item)
72 
73 #undef __field_desc
74 #define __field_desc(type, container, item)
75 
76 #undef __field_packed
77 #define __field_packed(type, container, item)
78 
79 #undef __array
80 #define __array(type, item, size)	type	item[size];
81 
82 /*
83  * For backward compatibility, older user space expects to see the
84  * kernel_stack event with a fixed size caller field. But today the fix
85  * size is ignored by the kernel, and the real structure is dynamic.
86  * Expose to user space: "unsigned long caller[8];" but the real structure
87  * will be "unsigned long caller[] __counted_by(size)"
88  */
89 #undef __stack_array
90 #define __stack_array(type, item, size, field)		type item[] __counted_by(field);
91 
92 #undef __array_desc
93 #define __array_desc(type, container, item, size)
94 
95 #undef __dynamic_array
96 #define __dynamic_array(type, item)	type	item[];
97 
98 #undef __rel_dynamic_array
99 #define __rel_dynamic_array(type, item)	type	item[];
100 
101 #undef F_STRUCT
102 #define F_STRUCT(args...)		args
103 
104 #undef FTRACE_ENTRY
105 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print)		\
106 	struct struct_name {						\
107 		struct trace_entry	ent;				\
108 		tstruct							\
109 	}
110 
111 #undef FTRACE_ENTRY_DUP
112 #define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk)
113 
114 #undef FTRACE_ENTRY_REG
115 #define FTRACE_ENTRY_REG(name, struct_name, id, tstruct, print,	regfn)	\
116 	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print))
117 
118 #undef FTRACE_ENTRY_PACKED
119 #define FTRACE_ENTRY_PACKED(name, struct_name, id, tstruct, print)	\
120 	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print)) __packed
121 
122 #include "trace_entries.h"
123 
124 /* Use this for memory failure errors */
125 #define MEM_FAIL(condition, fmt, ...)					\
126 	DO_ONCE_LITE_IF(condition, pr_err, "ERROR: " fmt, ##__VA_ARGS__)
127 
128 #define FAULT_STRING "(fault)"
129 
130 #define HIST_STACKTRACE_DEPTH	16
131 #define HIST_STACKTRACE_SIZE	(HIST_STACKTRACE_DEPTH * sizeof(unsigned long))
132 #define HIST_STACKTRACE_SKIP	5
133 
134 /*
135  * syscalls are special, and need special handling, this is why
136  * they are not included in trace_entries.h
137  */
138 struct syscall_trace_enter {
139 	struct trace_entry	ent;
140 	int			nr;
141 	unsigned long		args[];
142 };
143 
144 struct syscall_trace_exit {
145 	struct trace_entry	ent;
146 	int			nr;
147 	long			ret;
148 };
149 
150 struct kprobe_trace_entry_head {
151 	struct trace_entry	ent;
152 	unsigned long		ip;
153 };
154 
155 struct eprobe_trace_entry_head {
156 	struct trace_entry	ent;
157 };
158 
159 struct kretprobe_trace_entry_head {
160 	struct trace_entry	ent;
161 	unsigned long		func;
162 	unsigned long		ret_ip;
163 };
164 
165 struct fentry_trace_entry_head {
166 	struct trace_entry	ent;
167 	unsigned long		ip;
168 };
169 
170 struct fexit_trace_entry_head {
171 	struct trace_entry	ent;
172 	unsigned long		func;
173 	unsigned long		ret_ip;
174 };
175 
176 #define TRACE_BUF_SIZE		1024
177 
178 struct trace_array;
179 
180 /*
181  * The CPU trace array - it consists of thousands of trace entries
182  * plus some other descriptor data: (for example which task started
183  * the trace, etc.)
184  */
185 struct trace_array_cpu {
186 	atomic_t		disabled;
187 	void			*buffer_page;	/* ring buffer spare */
188 
189 	unsigned long		entries;
190 	unsigned long		saved_latency;
191 	unsigned long		critical_start;
192 	unsigned long		critical_end;
193 	unsigned long		critical_sequence;
194 	unsigned long		nice;
195 	unsigned long		policy;
196 	unsigned long		rt_priority;
197 	unsigned long		skipped_entries;
198 	u64			preempt_timestamp;
199 	pid_t			pid;
200 	kuid_t			uid;
201 	char			comm[TASK_COMM_LEN];
202 
203 #ifdef CONFIG_FUNCTION_TRACER
204 	int			ftrace_ignore_pid;
205 #endif
206 	bool			ignore_pid;
207 };
208 
209 struct tracer;
210 struct trace_option_dentry;
211 
212 struct array_buffer {
213 	struct trace_array		*tr;
214 	struct trace_buffer		*buffer;
215 	struct trace_array_cpu __percpu	*data;
216 	u64				time_start;
217 	int				cpu;
218 };
219 
220 #define TRACE_FLAGS_MAX_SIZE		32
221 
222 struct trace_options {
223 	struct tracer			*tracer;
224 	struct trace_option_dentry	*topts;
225 };
226 
227 struct trace_pid_list *trace_pid_list_alloc(void);
228 void trace_pid_list_free(struct trace_pid_list *pid_list);
229 bool trace_pid_list_is_set(struct trace_pid_list *pid_list, unsigned int pid);
230 int trace_pid_list_set(struct trace_pid_list *pid_list, unsigned int pid);
231 int trace_pid_list_clear(struct trace_pid_list *pid_list, unsigned int pid);
232 int trace_pid_list_first(struct trace_pid_list *pid_list, unsigned int *pid);
233 int trace_pid_list_next(struct trace_pid_list *pid_list, unsigned int pid,
234 			unsigned int *next);
235 
236 enum {
237 	TRACE_PIDS		= BIT(0),
238 	TRACE_NO_PIDS		= BIT(1),
239 };
240 
pid_type_enabled(int type,struct trace_pid_list * pid_list,struct trace_pid_list * no_pid_list)241 static inline bool pid_type_enabled(int type, struct trace_pid_list *pid_list,
242 				    struct trace_pid_list *no_pid_list)
243 {
244 	/* Return true if the pid list in type has pids */
245 	return ((type & TRACE_PIDS) && pid_list) ||
246 		((type & TRACE_NO_PIDS) && no_pid_list);
247 }
248 
still_need_pid_events(int type,struct trace_pid_list * pid_list,struct trace_pid_list * no_pid_list)249 static inline bool still_need_pid_events(int type, struct trace_pid_list *pid_list,
250 					 struct trace_pid_list *no_pid_list)
251 {
252 	/*
253 	 * Turning off what is in @type, return true if the "other"
254 	 * pid list, still has pids in it.
255 	 */
256 	return (!(type & TRACE_PIDS) && pid_list) ||
257 		(!(type & TRACE_NO_PIDS) && no_pid_list);
258 }
259 
260 typedef bool (*cond_update_fn_t)(struct trace_array *tr, void *cond_data);
261 
262 /**
263  * struct cond_snapshot - conditional snapshot data and callback
264  *
265  * The cond_snapshot structure encapsulates a callback function and
266  * data associated with the snapshot for a given tracing instance.
267  *
268  * When a snapshot is taken conditionally, by invoking
269  * tracing_snapshot_cond(tr, cond_data), the cond_data passed in is
270  * passed in turn to the cond_snapshot.update() function.  That data
271  * can be compared by the update() implementation with the cond_data
272  * contained within the struct cond_snapshot instance associated with
273  * the trace_array.  Because the tr->max_lock is held throughout the
274  * update() call, the update() function can directly retrieve the
275  * cond_snapshot and cond_data associated with the per-instance
276  * snapshot associated with the trace_array.
277  *
278  * The cond_snapshot.update() implementation can save data to be
279  * associated with the snapshot if it decides to, and returns 'true'
280  * in that case, or it returns 'false' if the conditional snapshot
281  * shouldn't be taken.
282  *
283  * The cond_snapshot instance is created and associated with the
284  * user-defined cond_data by tracing_cond_snapshot_enable().
285  * Likewise, the cond_snapshot instance is destroyed and is no longer
286  * associated with the trace instance by
287  * tracing_cond_snapshot_disable().
288  *
289  * The method below is required.
290  *
291  * @update: When a conditional snapshot is invoked, the update()
292  *	callback function is invoked with the tr->max_lock held.  The
293  *	update() implementation signals whether or not to actually
294  *	take the snapshot, by returning 'true' if so, 'false' if no
295  *	snapshot should be taken.  Because the max_lock is held for
296  *	the duration of update(), the implementation is safe to
297  *	directly retrieved and save any implementation data it needs
298  *	to in association with the snapshot.
299  */
300 struct cond_snapshot {
301 	void				*cond_data;
302 	cond_update_fn_t		update;
303 };
304 
305 /*
306  * struct trace_func_repeats - used to keep track of the consecutive
307  * (on the same CPU) calls of a single function.
308  */
309 struct trace_func_repeats {
310 	unsigned long	ip;
311 	unsigned long	parent_ip;
312 	unsigned long	count;
313 	u64		ts_last_call;
314 };
315 
316 struct trace_module_delta {
317 	struct rcu_head	rcu;
318 	long		delta[];
319 };
320 
321 /*
322  * The trace array - an array of per-CPU trace arrays. This is the
323  * highest level data structure that individual tracers deal with.
324  * They have on/off state as well:
325  */
326 struct trace_array {
327 	struct list_head	list;
328 	char			*name;
329 	struct array_buffer	array_buffer;
330 #ifdef CONFIG_TRACER_MAX_TRACE
331 	/*
332 	 * The max_buffer is used to snapshot the trace when a maximum
333 	 * latency is reached, or when the user initiates a snapshot.
334 	 * Some tracers will use this to store a maximum trace while
335 	 * it continues examining live traces.
336 	 *
337 	 * The buffers for the max_buffer are set up the same as the array_buffer
338 	 * When a snapshot is taken, the buffer of the max_buffer is swapped
339 	 * with the buffer of the array_buffer and the buffers are reset for
340 	 * the array_buffer so the tracing can continue.
341 	 */
342 	struct array_buffer	max_buffer;
343 	bool			allocated_snapshot;
344 	spinlock_t		snapshot_trigger_lock;
345 	unsigned int		snapshot;
346 	unsigned long		max_latency;
347 #ifdef CONFIG_FSNOTIFY
348 	struct dentry		*d_max_latency;
349 	struct work_struct	fsnotify_work;
350 	struct irq_work		fsnotify_irqwork;
351 #endif
352 #endif
353 	/* The below is for memory mapped ring buffer */
354 	unsigned int		mapped;
355 	unsigned long		range_addr_start;
356 	unsigned long		range_addr_size;
357 	char			*range_name;
358 	long			text_delta;
359 	struct trace_module_delta *module_delta;
360 	void			*scratch; /* pointer in persistent memory */
361 	int			scratch_size;
362 
363 	int			buffer_disabled;
364 
365 	struct trace_pid_list	__rcu *filtered_pids;
366 	struct trace_pid_list	__rcu *filtered_no_pids;
367 	/*
368 	 * max_lock is used to protect the swapping of buffers
369 	 * when taking a max snapshot. The buffers themselves are
370 	 * protected by per_cpu spinlocks. But the action of the swap
371 	 * needs its own lock.
372 	 *
373 	 * This is defined as a arch_spinlock_t in order to help
374 	 * with performance when lockdep debugging is enabled.
375 	 *
376 	 * It is also used in other places outside the update_max_tr
377 	 * so it needs to be defined outside of the
378 	 * CONFIG_TRACER_MAX_TRACE.
379 	 */
380 	arch_spinlock_t		max_lock;
381 #ifdef CONFIG_FTRACE_SYSCALLS
382 	int			sys_refcount_enter;
383 	int			sys_refcount_exit;
384 	struct trace_event_file __rcu *enter_syscall_files[NR_syscalls];
385 	struct trace_event_file __rcu *exit_syscall_files[NR_syscalls];
386 #endif
387 	int			stop_count;
388 	int			clock_id;
389 	int			nr_topts;
390 	bool			clear_trace;
391 	int			buffer_percent;
392 	unsigned int		n_err_log_entries;
393 	struct tracer		*current_trace;
394 	unsigned int		trace_flags;
395 	unsigned char		trace_flags_index[TRACE_FLAGS_MAX_SIZE];
396 	unsigned int		flags;
397 	raw_spinlock_t		start_lock;
398 	const char		*system_names;
399 	struct list_head	err_log;
400 	struct dentry		*dir;
401 	struct dentry		*options;
402 	struct dentry		*percpu_dir;
403 	struct eventfs_inode	*event_dir;
404 	struct trace_options	*topts;
405 	struct list_head	systems;
406 	struct list_head	events;
407 	struct trace_event_file *trace_marker_file;
408 	cpumask_var_t		tracing_cpumask; /* only trace on set CPUs */
409 	/* one per_cpu trace_pipe can be opened by only one user */
410 	cpumask_var_t		pipe_cpumask;
411 	int			ref;
412 	int			trace_ref;
413 #ifdef CONFIG_MODULES
414 	struct list_head	mod_events;
415 #endif
416 #ifdef CONFIG_FUNCTION_TRACER
417 	struct ftrace_ops	*ops;
418 	struct trace_pid_list	__rcu *function_pids;
419 	struct trace_pid_list	__rcu *function_no_pids;
420 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
421 	struct fgraph_ops	*gops;
422 #endif
423 #ifdef CONFIG_DYNAMIC_FTRACE
424 	/* All of these are protected by the ftrace_lock */
425 	struct list_head	func_probes;
426 	struct list_head	mod_trace;
427 	struct list_head	mod_notrace;
428 #endif
429 	/* function tracing enabled */
430 	int			function_enabled;
431 #endif
432 	int			no_filter_buffering_ref;
433 	struct list_head	hist_vars;
434 #ifdef CONFIG_TRACER_SNAPSHOT
435 	struct cond_snapshot	*cond_snapshot;
436 #endif
437 	struct trace_func_repeats	__percpu *last_func_repeats;
438 	/*
439 	 * On boot up, the ring buffer is set to the minimum size, so that
440 	 * we do not waste memory on systems that are not using tracing.
441 	 */
442 	bool ring_buffer_expanded;
443 };
444 
445 enum {
446 	TRACE_ARRAY_FL_GLOBAL		= BIT(0),
447 	TRACE_ARRAY_FL_BOOT		= BIT(1),
448 	TRACE_ARRAY_FL_LAST_BOOT	= BIT(2),
449 	TRACE_ARRAY_FL_MOD_INIT		= BIT(3),
450 	TRACE_ARRAY_FL_MEMMAP		= BIT(4),
451 };
452 
453 #ifdef CONFIG_MODULES
454 bool module_exists(const char *module);
455 #else
module_exists(const char * module)456 static inline bool module_exists(const char *module)
457 {
458 	return false;
459 }
460 #endif
461 
462 extern struct list_head ftrace_trace_arrays;
463 
464 extern struct mutex trace_types_lock;
465 
466 extern int trace_array_get(struct trace_array *tr);
467 extern int tracing_check_open_get_tr(struct trace_array *tr);
468 extern struct trace_array *trace_array_find(const char *instance);
469 extern struct trace_array *trace_array_find_get(const char *instance);
470 
471 extern u64 tracing_event_time_stamp(struct trace_buffer *buffer, struct ring_buffer_event *rbe);
472 extern int tracing_set_filter_buffering(struct trace_array *tr, bool set);
473 extern int tracing_set_clock(struct trace_array *tr, const char *clockstr);
474 
475 extern bool trace_clock_in_ns(struct trace_array *tr);
476 
477 extern unsigned long trace_adjust_address(struct trace_array *tr, unsigned long addr);
478 
479 /*
480  * The global tracer (top) should be the first trace array added,
481  * but we check the flag anyway.
482  */
top_trace_array(void)483 static inline struct trace_array *top_trace_array(void)
484 {
485 	struct trace_array *tr;
486 
487 	if (list_empty(&ftrace_trace_arrays))
488 		return NULL;
489 
490 	tr = list_entry(ftrace_trace_arrays.prev,
491 			typeof(*tr), list);
492 	WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
493 	return tr;
494 }
495 
496 #define FTRACE_CMP_TYPE(var, type) \
497 	__builtin_types_compatible_p(typeof(var), type *)
498 
499 #undef IF_ASSIGN
500 #define IF_ASSIGN(var, entry, etype, id)			\
501 	if (FTRACE_CMP_TYPE(var, etype)) {			\
502 		var = (typeof(var))(entry);			\
503 		WARN_ON(id != 0 && (entry)->type != id);	\
504 		break;						\
505 	}
506 
507 /* Will cause compile errors if type is not found. */
508 extern void __ftrace_bad_type(void);
509 
510 /*
511  * The trace_assign_type is a verifier that the entry type is
512  * the same as the type being assigned. To add new types simply
513  * add a line with the following format:
514  *
515  * IF_ASSIGN(var, ent, type, id);
516  *
517  *  Where "type" is the trace type that includes the trace_entry
518  *  as the "ent" item. And "id" is the trace identifier that is
519  *  used in the trace_type enum.
520  *
521  *  If the type can have more than one id, then use zero.
522  */
523 #define trace_assign_type(var, ent)					\
524 	do {								\
525 		IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);	\
526 		IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);	\
527 		IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);	\
528 		IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
529 		IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);	\
530 		IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT);	\
531 		IF_ASSIGN(var, ent, struct bputs_entry, TRACE_BPUTS);	\
532 		IF_ASSIGN(var, ent, struct hwlat_entry, TRACE_HWLAT);	\
533 		IF_ASSIGN(var, ent, struct osnoise_entry, TRACE_OSNOISE);\
534 		IF_ASSIGN(var, ent, struct timerlat_entry, TRACE_TIMERLAT);\
535 		IF_ASSIGN(var, ent, struct raw_data_entry, TRACE_RAW_DATA);\
536 		IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,		\
537 			  TRACE_MMIO_RW);				\
538 		IF_ASSIGN(var, ent, struct trace_mmiotrace_map,		\
539 			  TRACE_MMIO_MAP);				\
540 		IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
541 		IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,	\
542 			  TRACE_GRAPH_ENT);		\
543 		IF_ASSIGN(var, ent, struct fgraph_retaddr_ent_entry,\
544 			  TRACE_GRAPH_RETADDR_ENT);		\
545 		IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,	\
546 			  TRACE_GRAPH_RET);		\
547 		IF_ASSIGN(var, ent, struct func_repeats_entry,		\
548 			  TRACE_FUNC_REPEATS);				\
549 		__ftrace_bad_type();					\
550 	} while (0)
551 
552 /*
553  * An option specific to a tracer. This is a boolean value.
554  * The bit is the bit index that sets its value on the
555  * flags value in struct tracer_flags.
556  */
557 struct tracer_opt {
558 	const char	*name; /* Will appear on the trace_options file */
559 	u32		bit; /* Mask assigned in val field in tracer_flags */
560 };
561 
562 /*
563  * The set of specific options for a tracer. Your tracer
564  * have to set the initial value of the flags val.
565  */
566 struct tracer_flags {
567 	u32			val;
568 	struct tracer_opt	*opts;
569 	struct tracer		*trace;
570 };
571 
572 /* Makes more easy to define a tracer opt */
573 #define TRACER_OPT(s, b)	.name = #s, .bit = b
574 
575 
576 struct trace_option_dentry {
577 	struct tracer_opt		*opt;
578 	struct tracer_flags		*flags;
579 	struct trace_array		*tr;
580 	struct dentry			*entry;
581 };
582 
583 /**
584  * struct tracer - a specific tracer and its callbacks to interact with tracefs
585  * @name: the name chosen to select it on the available_tracers file
586  * @init: called when one switches to this tracer (echo name > current_tracer)
587  * @reset: called when one switches to another tracer
588  * @start: called when tracing is unpaused (echo 1 > tracing_on)
589  * @stop: called when tracing is paused (echo 0 > tracing_on)
590  * @update_thresh: called when tracing_thresh is updated
591  * @open: called when the trace file is opened
592  * @pipe_open: called when the trace_pipe file is opened
593  * @close: called when the trace file is released
594  * @pipe_close: called when the trace_pipe file is released
595  * @read: override the default read callback on trace_pipe
596  * @splice_read: override the default splice_read callback on trace_pipe
597  * @selftest: selftest to run on boot (see trace_selftest.c)
598  * @print_headers: override the first lines that describe your columns
599  * @print_line: callback that prints a trace
600  * @set_flag: signals one of your private flags changed (trace_options file)
601  * @flags: your private flags
602  */
603 struct tracer {
604 	const char		*name;
605 	int			(*init)(struct trace_array *tr);
606 	void			(*reset)(struct trace_array *tr);
607 	void			(*start)(struct trace_array *tr);
608 	void			(*stop)(struct trace_array *tr);
609 	int			(*update_thresh)(struct trace_array *tr);
610 	void			(*open)(struct trace_iterator *iter);
611 	void			(*pipe_open)(struct trace_iterator *iter);
612 	void			(*close)(struct trace_iterator *iter);
613 	void			(*pipe_close)(struct trace_iterator *iter);
614 	ssize_t			(*read)(struct trace_iterator *iter,
615 					struct file *filp, char __user *ubuf,
616 					size_t cnt, loff_t *ppos);
617 	ssize_t			(*splice_read)(struct trace_iterator *iter,
618 					       struct file *filp,
619 					       loff_t *ppos,
620 					       struct pipe_inode_info *pipe,
621 					       size_t len,
622 					       unsigned int flags);
623 #ifdef CONFIG_FTRACE_STARTUP_TEST
624 	int			(*selftest)(struct tracer *trace,
625 					    struct trace_array *tr);
626 #endif
627 	void			(*print_header)(struct seq_file *m);
628 	enum print_line_t	(*print_line)(struct trace_iterator *iter);
629 	/* If you handled the flag setting, return 0 */
630 	int			(*set_flag)(struct trace_array *tr,
631 					    u32 old_flags, u32 bit, int set);
632 	/* Return 0 if OK with change, else return non-zero */
633 	int			(*flag_changed)(struct trace_array *tr,
634 						u32 mask, int set);
635 	struct tracer		*next;
636 	struct tracer_flags	*flags;
637 	int			enabled;
638 	bool			print_max;
639 	bool			allow_instances;
640 #ifdef CONFIG_TRACER_MAX_TRACE
641 	bool			use_max_tr;
642 #endif
643 	/* True if tracer cannot be enabled in kernel param */
644 	bool			noboot;
645 };
646 
647 static inline struct ring_buffer_iter *
trace_buffer_iter(struct trace_iterator * iter,int cpu)648 trace_buffer_iter(struct trace_iterator *iter, int cpu)
649 {
650 	return iter->buffer_iter ? iter->buffer_iter[cpu] : NULL;
651 }
652 
653 int tracer_init(struct tracer *t, struct trace_array *tr);
654 int tracing_is_enabled(void);
655 void tracing_reset_online_cpus(struct array_buffer *buf);
656 void tracing_reset_all_online_cpus(void);
657 void tracing_reset_all_online_cpus_unlocked(void);
658 int tracing_open_generic(struct inode *inode, struct file *filp);
659 int tracing_open_generic_tr(struct inode *inode, struct file *filp);
660 int tracing_release_generic_tr(struct inode *inode, struct file *file);
661 int tracing_open_file_tr(struct inode *inode, struct file *filp);
662 int tracing_release_file_tr(struct inode *inode, struct file *filp);
663 int tracing_single_release_file_tr(struct inode *inode, struct file *filp);
664 bool tracing_is_disabled(void);
665 bool tracer_tracing_is_on(struct trace_array *tr);
666 void tracer_tracing_on(struct trace_array *tr);
667 void tracer_tracing_off(struct trace_array *tr);
668 struct dentry *trace_create_file(const char *name,
669 				 umode_t mode,
670 				 struct dentry *parent,
671 				 void *data,
672 				 const struct file_operations *fops);
673 
674 int tracing_init_dentry(void);
675 
676 struct ring_buffer_event;
677 
678 struct ring_buffer_event *
679 trace_buffer_lock_reserve(struct trace_buffer *buffer,
680 			  int type,
681 			  unsigned long len,
682 			  unsigned int trace_ctx);
683 
684 int ring_buffer_meta_seq_init(struct file *file, struct trace_buffer *buffer, int cpu);
685 
686 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
687 						struct trace_array_cpu *data);
688 
689 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
690 					  int *ent_cpu, u64 *ent_ts);
691 
692 void trace_buffer_unlock_commit_nostack(struct trace_buffer *buffer,
693 					struct ring_buffer_event *event);
694 
695 bool trace_is_tracepoint_string(const char *str);
696 const char *trace_event_format(struct trace_iterator *iter, const char *fmt);
697 char *trace_iter_expand_format(struct trace_iterator *iter);
698 bool ignore_event(struct trace_iterator *iter);
699 
700 int trace_empty(struct trace_iterator *iter);
701 
702 void *trace_find_next_entry_inc(struct trace_iterator *iter);
703 
704 void trace_init_global_iter(struct trace_iterator *iter);
705 
706 void tracing_iter_reset(struct trace_iterator *iter, int cpu);
707 
708 unsigned long trace_total_entries_cpu(struct trace_array *tr, int cpu);
709 unsigned long trace_total_entries(struct trace_array *tr);
710 
711 void trace_function(struct trace_array *tr,
712 		    unsigned long ip,
713 		    unsigned long parent_ip,
714 		    unsigned int trace_ctx,
715 		    struct ftrace_regs *regs);
716 void trace_graph_function(struct trace_array *tr,
717 		    unsigned long ip,
718 		    unsigned long parent_ip,
719 		    unsigned int trace_ctx);
720 void trace_latency_header(struct seq_file *m);
721 void trace_default_header(struct seq_file *m);
722 void print_trace_header(struct seq_file *m, struct trace_iterator *iter);
723 
724 void trace_graph_return(struct ftrace_graph_ret *trace, struct fgraph_ops *gops,
725 			struct ftrace_regs *fregs);
726 int trace_graph_entry(struct ftrace_graph_ent *trace, struct fgraph_ops *gops,
727 		      struct ftrace_regs *fregs);
728 
729 void tracing_start_cmdline_record(void);
730 void tracing_stop_cmdline_record(void);
731 void tracing_start_tgid_record(void);
732 void tracing_stop_tgid_record(void);
733 
734 int register_tracer(struct tracer *type);
735 int is_tracing_stopped(void);
736 
737 loff_t tracing_lseek(struct file *file, loff_t offset, int whence);
738 
739 extern cpumask_var_t __read_mostly tracing_buffer_mask;
740 
741 #define for_each_tracing_cpu(cpu)	\
742 	for_each_cpu(cpu, tracing_buffer_mask)
743 
744 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
745 
746 extern unsigned long tracing_thresh;
747 
748 /* PID filtering */
749 
750 bool trace_find_filtered_pid(struct trace_pid_list *filtered_pids,
751 			     pid_t search_pid);
752 bool trace_ignore_this_task(struct trace_pid_list *filtered_pids,
753 			    struct trace_pid_list *filtered_no_pids,
754 			    struct task_struct *task);
755 void trace_filter_add_remove_task(struct trace_pid_list *pid_list,
756 				  struct task_struct *self,
757 				  struct task_struct *task);
758 void *trace_pid_next(struct trace_pid_list *pid_list, void *v, loff_t *pos);
759 void *trace_pid_start(struct trace_pid_list *pid_list, loff_t *pos);
760 int trace_pid_show(struct seq_file *m, void *v);
761 int trace_pid_write(struct trace_pid_list *filtered_pids,
762 		    struct trace_pid_list **new_pid_list,
763 		    const char __user *ubuf, size_t cnt);
764 
765 #ifdef CONFIG_TRACER_MAX_TRACE
766 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu,
767 		   void *cond_data);
768 void update_max_tr_single(struct trace_array *tr,
769 			  struct task_struct *tsk, int cpu);
770 
771 #ifdef CONFIG_FSNOTIFY
772 #define LATENCY_FS_NOTIFY
773 #endif
774 #endif /* CONFIG_TRACER_MAX_TRACE */
775 
776 #ifdef LATENCY_FS_NOTIFY
777 void latency_fsnotify(struct trace_array *tr);
778 #else
latency_fsnotify(struct trace_array * tr)779 static inline void latency_fsnotify(struct trace_array *tr) { }
780 #endif
781 
782 #ifdef CONFIG_STACKTRACE
783 void __trace_stack(struct trace_array *tr, unsigned int trace_ctx, int skip);
784 #else
__trace_stack(struct trace_array * tr,unsigned int trace_ctx,int skip)785 static inline void __trace_stack(struct trace_array *tr, unsigned int trace_ctx,
786 				 int skip)
787 {
788 }
789 #endif /* CONFIG_STACKTRACE */
790 
791 void trace_last_func_repeats(struct trace_array *tr,
792 			     struct trace_func_repeats *last_info,
793 			     unsigned int trace_ctx);
794 
795 extern u64 ftrace_now(int cpu);
796 
797 extern void trace_find_cmdline(int pid, char comm[]);
798 extern int trace_find_tgid(int pid);
799 extern void trace_event_follow_fork(struct trace_array *tr, bool enable);
800 
801 extern int trace_events_enabled(struct trace_array *tr, const char *system);
802 
803 #ifdef CONFIG_DYNAMIC_FTRACE
804 extern unsigned long ftrace_update_tot_cnt;
805 extern unsigned long ftrace_number_of_pages;
806 extern unsigned long ftrace_number_of_groups;
807 extern u64 ftrace_update_time;
808 extern u64 ftrace_total_mod_time;
809 void ftrace_init_trace_array(struct trace_array *tr);
810 #else
ftrace_init_trace_array(struct trace_array * tr)811 static inline void ftrace_init_trace_array(struct trace_array *tr) { }
812 #endif
813 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
814 extern int DYN_FTRACE_TEST_NAME(void);
815 #define DYN_FTRACE_TEST_NAME2 trace_selftest_dynamic_test_func2
816 extern int DYN_FTRACE_TEST_NAME2(void);
817 
818 extern void trace_set_ring_buffer_expanded(struct trace_array *tr);
819 extern bool tracing_selftest_disabled;
820 
821 #ifdef CONFIG_FTRACE_STARTUP_TEST
822 extern void __init disable_tracing_selftest(const char *reason);
823 
824 extern int trace_selftest_startup_function(struct tracer *trace,
825 					   struct trace_array *tr);
826 extern int trace_selftest_startup_function_graph(struct tracer *trace,
827 						 struct trace_array *tr);
828 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
829 					  struct trace_array *tr);
830 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
831 					     struct trace_array *tr);
832 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
833 						 struct trace_array *tr);
834 extern int trace_selftest_startup_wakeup(struct tracer *trace,
835 					 struct trace_array *tr);
836 extern int trace_selftest_startup_nop(struct tracer *trace,
837 					 struct trace_array *tr);
838 extern int trace_selftest_startup_branch(struct tracer *trace,
839 					 struct trace_array *tr);
840 /*
841  * Tracer data references selftest functions that only occur
842  * on boot up. These can be __init functions. Thus, when selftests
843  * are enabled, then the tracers need to reference __init functions.
844  */
845 #define __tracer_data		__refdata
846 #else
disable_tracing_selftest(const char * reason)847 static inline void __init disable_tracing_selftest(const char *reason)
848 {
849 }
850 /* Tracers are seldom changed. Optimize when selftests are disabled. */
851 #define __tracer_data		__read_mostly
852 #endif /* CONFIG_FTRACE_STARTUP_TEST */
853 
854 extern void *head_page(struct trace_array_cpu *data);
855 extern unsigned long long ns2usecs(u64 nsec);
856 
857 __printf(2, 0)
858 int trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
859 __printf(2, 0)
860 int trace_vprintk(unsigned long ip, const char *fmt, va_list args);
861 __printf(3, 0)
862 int trace_array_vprintk(struct trace_array *tr,
863 			unsigned long ip, const char *fmt, va_list args);
864 __printf(3, 4)
865 int trace_array_printk_buf(struct trace_buffer *buffer,
866 			   unsigned long ip, const char *fmt, ...);
867 void trace_printk_seq(struct trace_seq *s);
868 enum print_line_t print_trace_line(struct trace_iterator *iter);
869 
870 extern char trace_find_mark(unsigned long long duration);
871 
872 struct ftrace_hash;
873 
874 struct ftrace_mod_load {
875 	struct list_head	list;
876 	char			*func;
877 	char			*module;
878 	int			 enable;
879 };
880 
881 enum {
882 	FTRACE_HASH_FL_MOD	= (1 << 0),
883 };
884 
885 struct ftrace_hash {
886 	unsigned long		size_bits;
887 	struct hlist_head	*buckets;
888 	unsigned long		count;
889 	unsigned long		flags;
890 	struct rcu_head		rcu;
891 };
892 
893 struct ftrace_func_entry *
894 ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip);
895 
ftrace_hash_empty(struct ftrace_hash * hash)896 static __always_inline bool ftrace_hash_empty(struct ftrace_hash *hash)
897 {
898 	return !hash || !(hash->count || (hash->flags & FTRACE_HASH_FL_MOD));
899 }
900 
901 /* Standard output formatting function used for function return traces */
902 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
903 
904 /* Flag options */
905 #define TRACE_GRAPH_PRINT_OVERRUN       0x1
906 #define TRACE_GRAPH_PRINT_CPU           0x2
907 #define TRACE_GRAPH_PRINT_OVERHEAD      0x4
908 #define TRACE_GRAPH_PRINT_PROC          0x8
909 #define TRACE_GRAPH_PRINT_DURATION      0x10
910 #define TRACE_GRAPH_PRINT_ABS_TIME      0x20
911 #define TRACE_GRAPH_PRINT_REL_TIME      0x40
912 #define TRACE_GRAPH_PRINT_IRQS          0x80
913 #define TRACE_GRAPH_PRINT_TAIL          0x100
914 #define TRACE_GRAPH_SLEEP_TIME          0x200
915 #define TRACE_GRAPH_GRAPH_TIME          0x400
916 #define TRACE_GRAPH_PRINT_RETVAL        0x800
917 #define TRACE_GRAPH_PRINT_RETVAL_HEX    0x1000
918 #define TRACE_GRAPH_PRINT_RETADDR       0x2000
919 #define TRACE_GRAPH_ARGS		0x4000
920 #define TRACE_GRAPH_PRINT_FILL_SHIFT	28
921 #define TRACE_GRAPH_PRINT_FILL_MASK	(0x3 << TRACE_GRAPH_PRINT_FILL_SHIFT)
922 
923 extern void ftrace_graph_sleep_time_control(bool enable);
924 
925 #ifdef CONFIG_FUNCTION_PROFILER
926 extern void ftrace_graph_graph_time_control(bool enable);
927 #else
ftrace_graph_graph_time_control(bool enable)928 static inline void ftrace_graph_graph_time_control(bool enable) { }
929 #endif
930 
931 extern enum print_line_t
932 print_graph_function_flags(struct trace_iterator *iter, u32 flags);
933 extern void print_graph_headers_flags(struct seq_file *s, u32 flags);
934 extern void
935 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
936 extern void graph_trace_open(struct trace_iterator *iter);
937 extern void graph_trace_close(struct trace_iterator *iter);
938 extern int __trace_graph_entry(struct trace_array *tr,
939 			       struct ftrace_graph_ent *trace,
940 			       unsigned int trace_ctx);
941 extern int __trace_graph_retaddr_entry(struct trace_array *tr,
942 				struct ftrace_graph_ent *trace,
943 				unsigned int trace_ctx,
944 				unsigned long retaddr);
945 extern void __trace_graph_return(struct trace_array *tr,
946 				 struct ftrace_graph_ret *trace,
947 				 unsigned int trace_ctx,
948 				 u64 calltime, u64 rettime);
949 
950 extern void init_array_fgraph_ops(struct trace_array *tr, struct ftrace_ops *ops);
951 extern int allocate_fgraph_ops(struct trace_array *tr, struct ftrace_ops *ops);
952 extern void free_fgraph_ops(struct trace_array *tr);
953 
954 enum {
955 	TRACE_GRAPH_FL		= 1,
956 
957 	/*
958 	 * In the very unlikely case that an interrupt came in
959 	 * at a start of graph tracing, and we want to trace
960 	 * the function in that interrupt, the depth can be greater
961 	 * than zero, because of the preempted start of a previous
962 	 * trace. In an even more unlikely case, depth could be 2
963 	 * if a softirq interrupted the start of graph tracing,
964 	 * followed by an interrupt preempting a start of graph
965 	 * tracing in the softirq, and depth can even be 3
966 	 * if an NMI came in at the start of an interrupt function
967 	 * that preempted a softirq start of a function that
968 	 * preempted normal context!!!! Luckily, it can't be
969 	 * greater than 3, so the next two bits are a mask
970 	 * of what the depth is when we set TRACE_GRAPH_FL
971 	 */
972 
973 	TRACE_GRAPH_DEPTH_START_BIT,
974 	TRACE_GRAPH_DEPTH_END_BIT,
975 
976 	/*
977 	 * To implement set_graph_notrace, if this bit is set, we ignore
978 	 * function graph tracing of called functions, until the return
979 	 * function is called to clear it.
980 	 */
981 	TRACE_GRAPH_NOTRACE_BIT,
982 };
983 
984 #define TRACE_GRAPH_NOTRACE		(1 << TRACE_GRAPH_NOTRACE_BIT)
985 
ftrace_graph_depth(unsigned long * task_var)986 static inline unsigned long ftrace_graph_depth(unsigned long *task_var)
987 {
988 	return (*task_var >> TRACE_GRAPH_DEPTH_START_BIT) & 3;
989 }
990 
ftrace_graph_set_depth(unsigned long * task_var,int depth)991 static inline void ftrace_graph_set_depth(unsigned long *task_var, int depth)
992 {
993 	*task_var &= ~(3 << TRACE_GRAPH_DEPTH_START_BIT);
994 	*task_var |= (depth & 3) << TRACE_GRAPH_DEPTH_START_BIT;
995 }
996 
997 #ifdef CONFIG_DYNAMIC_FTRACE
998 extern struct ftrace_hash __rcu *ftrace_graph_hash;
999 extern struct ftrace_hash __rcu *ftrace_graph_notrace_hash;
1000 
1001 static inline int
ftrace_graph_addr(unsigned long * task_var,struct ftrace_graph_ent * trace)1002 ftrace_graph_addr(unsigned long *task_var, struct ftrace_graph_ent *trace)
1003 {
1004 	unsigned long addr = trace->func;
1005 	int ret = 0;
1006 	struct ftrace_hash *hash;
1007 
1008 	preempt_disable_notrace();
1009 
1010 	/*
1011 	 * Have to open code "rcu_dereference_sched()" because the
1012 	 * function graph tracer can be called when RCU is not
1013 	 * "watching".
1014 	 * Protected with schedule_on_each_cpu(ftrace_sync)
1015 	 */
1016 	hash = rcu_dereference_protected(ftrace_graph_hash, !preemptible());
1017 
1018 	if (ftrace_hash_empty(hash)) {
1019 		ret = 1;
1020 		goto out;
1021 	}
1022 
1023 	if (ftrace_lookup_ip(hash, addr)) {
1024 		/*
1025 		 * This needs to be cleared on the return functions
1026 		 * when the depth is zero.
1027 		 */
1028 		*task_var |= TRACE_GRAPH_FL;
1029 		ftrace_graph_set_depth(task_var, trace->depth);
1030 
1031 		/*
1032 		 * If no irqs are to be traced, but a set_graph_function
1033 		 * is set, and called by an interrupt handler, we still
1034 		 * want to trace it.
1035 		 */
1036 		if (in_hardirq())
1037 			trace_recursion_set(TRACE_IRQ_BIT);
1038 		else
1039 			trace_recursion_clear(TRACE_IRQ_BIT);
1040 		ret = 1;
1041 	}
1042 
1043 out:
1044 	preempt_enable_notrace();
1045 	return ret;
1046 }
1047 
1048 static inline void
ftrace_graph_addr_finish(struct fgraph_ops * gops,struct ftrace_graph_ret * trace)1049 ftrace_graph_addr_finish(struct fgraph_ops *gops, struct ftrace_graph_ret *trace)
1050 {
1051 	unsigned long *task_var = fgraph_get_task_var(gops);
1052 
1053 	if ((*task_var & TRACE_GRAPH_FL) &&
1054 	    trace->depth == ftrace_graph_depth(task_var))
1055 		*task_var &= ~TRACE_GRAPH_FL;
1056 }
1057 
ftrace_graph_notrace_addr(unsigned long addr)1058 static inline int ftrace_graph_notrace_addr(unsigned long addr)
1059 {
1060 	int ret = 0;
1061 	struct ftrace_hash *notrace_hash;
1062 
1063 	preempt_disable_notrace();
1064 
1065 	/*
1066 	 * Have to open code "rcu_dereference_sched()" because the
1067 	 * function graph tracer can be called when RCU is not
1068 	 * "watching".
1069 	 * Protected with schedule_on_each_cpu(ftrace_sync)
1070 	 */
1071 	notrace_hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
1072 						 !preemptible());
1073 
1074 	if (ftrace_lookup_ip(notrace_hash, addr))
1075 		ret = 1;
1076 
1077 	preempt_enable_notrace();
1078 	return ret;
1079 }
1080 #else
ftrace_graph_addr(unsigned long * task_var,struct ftrace_graph_ent * trace)1081 static inline int ftrace_graph_addr(unsigned long *task_var, struct ftrace_graph_ent *trace)
1082 {
1083 	return 1;
1084 }
1085 
ftrace_graph_notrace_addr(unsigned long addr)1086 static inline int ftrace_graph_notrace_addr(unsigned long addr)
1087 {
1088 	return 0;
1089 }
ftrace_graph_addr_finish(struct fgraph_ops * gops,struct ftrace_graph_ret * trace)1090 static inline void ftrace_graph_addr_finish(struct fgraph_ops *gops, struct ftrace_graph_ret *trace)
1091 { }
1092 #endif /* CONFIG_DYNAMIC_FTRACE */
1093 
1094 extern unsigned int fgraph_max_depth;
1095 extern bool fgraph_sleep_time;
1096 
1097 static inline bool
ftrace_graph_ignore_func(struct fgraph_ops * gops,struct ftrace_graph_ent * trace)1098 ftrace_graph_ignore_func(struct fgraph_ops *gops, struct ftrace_graph_ent *trace)
1099 {
1100 	unsigned long *task_var = fgraph_get_task_var(gops);
1101 
1102 	/* trace it when it is-nested-in or is a function enabled. */
1103 	return !((*task_var & TRACE_GRAPH_FL) ||
1104 		 ftrace_graph_addr(task_var, trace)) ||
1105 		(trace->depth < 0) ||
1106 		(fgraph_max_depth && trace->depth >= fgraph_max_depth);
1107 }
1108 
1109 void fgraph_init_ops(struct ftrace_ops *dst_ops,
1110 		     struct ftrace_ops *src_ops);
1111 
1112 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
1113 static inline enum print_line_t
print_graph_function_flags(struct trace_iterator * iter,u32 flags)1114 print_graph_function_flags(struct trace_iterator *iter, u32 flags)
1115 {
1116 	return TRACE_TYPE_UNHANDLED;
1117 }
free_fgraph_ops(struct trace_array * tr)1118 static inline void free_fgraph_ops(struct trace_array *tr) { }
1119 /* ftrace_ops may not be defined */
1120 #define init_array_fgraph_ops(tr, ops) do { } while (0)
1121 #define allocate_fgraph_ops(tr, ops) ({ 0; })
1122 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
1123 
1124 extern struct list_head ftrace_pids;
1125 
1126 #ifdef CONFIG_FUNCTION_TRACER
1127 
1128 #define FTRACE_PID_IGNORE	-1
1129 #define FTRACE_PID_TRACE	-2
1130 
1131 struct ftrace_func_command {
1132 	struct list_head	list;
1133 	char			*name;
1134 	int			(*func)(struct trace_array *tr,
1135 					struct ftrace_hash *hash,
1136 					char *func, char *cmd,
1137 					char *params, int enable);
1138 };
1139 extern bool ftrace_filter_param __initdata;
ftrace_trace_task(struct trace_array * tr)1140 static inline int ftrace_trace_task(struct trace_array *tr)
1141 {
1142 	return this_cpu_read(tr->array_buffer.data->ftrace_ignore_pid) !=
1143 		FTRACE_PID_IGNORE;
1144 }
1145 extern int ftrace_is_dead(void);
1146 int ftrace_create_function_files(struct trace_array *tr,
1147 				 struct dentry *parent);
1148 void ftrace_destroy_function_files(struct trace_array *tr);
1149 int ftrace_allocate_ftrace_ops(struct trace_array *tr);
1150 void ftrace_free_ftrace_ops(struct trace_array *tr);
1151 void ftrace_init_global_array_ops(struct trace_array *tr);
1152 struct trace_array *trace_get_global_array(void);
1153 void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func);
1154 void ftrace_reset_array_ops(struct trace_array *tr);
1155 void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer);
1156 void ftrace_init_tracefs_toplevel(struct trace_array *tr,
1157 				  struct dentry *d_tracer);
1158 void ftrace_clear_pids(struct trace_array *tr);
1159 int init_function_trace(void);
1160 void ftrace_pid_follow_fork(struct trace_array *tr, bool enable);
1161 #else
ftrace_trace_task(struct trace_array * tr)1162 static inline int ftrace_trace_task(struct trace_array *tr)
1163 {
1164 	return 1;
1165 }
ftrace_is_dead(void)1166 static inline int ftrace_is_dead(void) { return 0; }
1167 static inline int
ftrace_create_function_files(struct trace_array * tr,struct dentry * parent)1168 ftrace_create_function_files(struct trace_array *tr,
1169 			     struct dentry *parent)
1170 {
1171 	return 0;
1172 }
ftrace_allocate_ftrace_ops(struct trace_array * tr)1173 static inline int ftrace_allocate_ftrace_ops(struct trace_array *tr)
1174 {
1175 	return 0;
1176 }
ftrace_free_ftrace_ops(struct trace_array * tr)1177 static inline void ftrace_free_ftrace_ops(struct trace_array *tr) { }
ftrace_destroy_function_files(struct trace_array * tr)1178 static inline void ftrace_destroy_function_files(struct trace_array *tr) { }
1179 static inline __init void
ftrace_init_global_array_ops(struct trace_array * tr)1180 ftrace_init_global_array_ops(struct trace_array *tr) { }
ftrace_reset_array_ops(struct trace_array * tr)1181 static inline void ftrace_reset_array_ops(struct trace_array *tr) { }
ftrace_init_tracefs(struct trace_array * tr,struct dentry * d)1182 static inline void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d) { }
ftrace_init_tracefs_toplevel(struct trace_array * tr,struct dentry * d)1183 static inline void ftrace_init_tracefs_toplevel(struct trace_array *tr, struct dentry *d) { }
ftrace_clear_pids(struct trace_array * tr)1184 static inline void ftrace_clear_pids(struct trace_array *tr) { }
init_function_trace(void)1185 static inline int init_function_trace(void) { return 0; }
ftrace_pid_follow_fork(struct trace_array * tr,bool enable)1186 static inline void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) { }
1187 /* ftace_func_t type is not defined, use macro instead of static inline */
1188 #define ftrace_init_array_ops(tr, func) do { } while (0)
1189 #endif /* CONFIG_FUNCTION_TRACER */
1190 
1191 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
1192 
1193 struct ftrace_probe_ops {
1194 	void			(*func)(unsigned long ip,
1195 					unsigned long parent_ip,
1196 					struct trace_array *tr,
1197 					struct ftrace_probe_ops *ops,
1198 					void *data);
1199 	int			(*init)(struct ftrace_probe_ops *ops,
1200 					struct trace_array *tr,
1201 					unsigned long ip, void *init_data,
1202 					void **data);
1203 	void			(*free)(struct ftrace_probe_ops *ops,
1204 					struct trace_array *tr,
1205 					unsigned long ip, void *data);
1206 	int			(*print)(struct seq_file *m,
1207 					 unsigned long ip,
1208 					 struct ftrace_probe_ops *ops,
1209 					 void *data);
1210 };
1211 
1212 struct ftrace_func_mapper;
1213 typedef int (*ftrace_mapper_func)(void *data);
1214 
1215 struct ftrace_func_mapper *allocate_ftrace_func_mapper(void);
1216 void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
1217 					   unsigned long ip);
1218 int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
1219 			       unsigned long ip, void *data);
1220 void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
1221 				   unsigned long ip);
1222 void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
1223 			     ftrace_mapper_func free_func);
1224 
1225 extern int
1226 register_ftrace_function_probe(char *glob, struct trace_array *tr,
1227 			       struct ftrace_probe_ops *ops, void *data);
1228 extern int
1229 unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
1230 				      struct ftrace_probe_ops *ops);
1231 extern void clear_ftrace_function_probes(struct trace_array *tr);
1232 
1233 int register_ftrace_command(struct ftrace_func_command *cmd);
1234 int unregister_ftrace_command(struct ftrace_func_command *cmd);
1235 
1236 void ftrace_create_filter_files(struct ftrace_ops *ops,
1237 				struct dentry *parent);
1238 void ftrace_destroy_filter_files(struct ftrace_ops *ops);
1239 
1240 extern int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
1241 			     int len, int reset);
1242 extern int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
1243 			      int len, int reset);
1244 #else
1245 struct ftrace_func_command;
1246 
register_ftrace_command(struct ftrace_func_command * cmd)1247 static inline __init int register_ftrace_command(struct ftrace_func_command *cmd)
1248 {
1249 	return -EINVAL;
1250 }
unregister_ftrace_command(char * cmd_name)1251 static inline __init int unregister_ftrace_command(char *cmd_name)
1252 {
1253 	return -EINVAL;
1254 }
clear_ftrace_function_probes(struct trace_array * tr)1255 static inline void clear_ftrace_function_probes(struct trace_array *tr)
1256 {
1257 }
1258 
1259 /*
1260  * The ops parameter passed in is usually undefined.
1261  * This must be a macro.
1262  */
1263 #define ftrace_create_filter_files(ops, parent) do { } while (0)
1264 #define ftrace_destroy_filter_files(ops) do { } while (0)
1265 #endif /* CONFIG_FUNCTION_TRACER && CONFIG_DYNAMIC_FTRACE */
1266 
1267 bool ftrace_event_is_function(struct trace_event_call *call);
1268 
1269 /*
1270  * struct trace_parser - servers for reading the user input separated by spaces
1271  * @cont: set if the input is not complete - no final space char was found
1272  * @buffer: holds the parsed user input
1273  * @idx: user input length
1274  * @size: buffer size
1275  */
1276 struct trace_parser {
1277 	bool		cont;
1278 	char		*buffer;
1279 	unsigned	idx;
1280 	unsigned	size;
1281 };
1282 
trace_parser_loaded(struct trace_parser * parser)1283 static inline bool trace_parser_loaded(struct trace_parser *parser)
1284 {
1285 	return (parser->idx != 0);
1286 }
1287 
trace_parser_cont(struct trace_parser * parser)1288 static inline bool trace_parser_cont(struct trace_parser *parser)
1289 {
1290 	return parser->cont;
1291 }
1292 
trace_parser_clear(struct trace_parser * parser)1293 static inline void trace_parser_clear(struct trace_parser *parser)
1294 {
1295 	parser->cont = false;
1296 	parser->idx = 0;
1297 }
1298 
1299 extern int trace_parser_get_init(struct trace_parser *parser, int size);
1300 extern void trace_parser_put(struct trace_parser *parser);
1301 extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
1302 	size_t cnt, loff_t *ppos);
1303 
1304 /*
1305  * Only create function graph options if function graph is configured.
1306  */
1307 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1308 # define FGRAPH_FLAGS						\
1309 		C(DISPLAY_GRAPH,	"display-graph"),
1310 #else
1311 # define FGRAPH_FLAGS
1312 #endif
1313 
1314 #ifdef CONFIG_BRANCH_TRACER
1315 # define BRANCH_FLAGS					\
1316 		C(BRANCH,		"branch"),
1317 #else
1318 # define BRANCH_FLAGS
1319 #endif
1320 
1321 #ifdef CONFIG_FUNCTION_TRACER
1322 # define FUNCTION_FLAGS						\
1323 		C(FUNCTION,		"function-trace"),	\
1324 		C(FUNC_FORK,		"function-fork"),
1325 # define FUNCTION_DEFAULT_FLAGS		TRACE_ITER_FUNCTION
1326 #else
1327 # define FUNCTION_FLAGS
1328 # define FUNCTION_DEFAULT_FLAGS		0UL
1329 # define TRACE_ITER_FUNC_FORK		0UL
1330 #endif
1331 
1332 #ifdef CONFIG_STACKTRACE
1333 # define STACK_FLAGS				\
1334 		C(STACKTRACE,		"stacktrace"),
1335 #else
1336 # define STACK_FLAGS
1337 #endif
1338 
1339 /*
1340  * trace_iterator_flags is an enumeration that defines bit
1341  * positions into trace_flags that controls the output.
1342  *
1343  * NOTE: These bits must match the trace_options array in
1344  *       trace.c (this macro guarantees it).
1345  */
1346 #define TRACE_FLAGS						\
1347 		C(PRINT_PARENT,		"print-parent"),	\
1348 		C(SYM_OFFSET,		"sym-offset"),		\
1349 		C(SYM_ADDR,		"sym-addr"),		\
1350 		C(VERBOSE,		"verbose"),		\
1351 		C(RAW,			"raw"),			\
1352 		C(HEX,			"hex"),			\
1353 		C(BIN,			"bin"),			\
1354 		C(BLOCK,		"block"),		\
1355 		C(FIELDS,		"fields"),		\
1356 		C(PRINTK,		"trace_printk"),	\
1357 		C(ANNOTATE,		"annotate"),		\
1358 		C(USERSTACKTRACE,	"userstacktrace"),	\
1359 		C(SYM_USEROBJ,		"sym-userobj"),		\
1360 		C(PRINTK_MSGONLY,	"printk-msg-only"),	\
1361 		C(CONTEXT_INFO,		"context-info"),   /* Print pid/cpu/time */ \
1362 		C(LATENCY_FMT,		"latency-format"),	\
1363 		C(RECORD_CMD,		"record-cmd"),		\
1364 		C(RECORD_TGID,		"record-tgid"),		\
1365 		C(OVERWRITE,		"overwrite"),		\
1366 		C(STOP_ON_FREE,		"disable_on_free"),	\
1367 		C(IRQ_INFO,		"irq-info"),		\
1368 		C(MARKERS,		"markers"),		\
1369 		C(EVENT_FORK,		"event-fork"),		\
1370 		C(TRACE_PRINTK,		"trace_printk_dest"),	\
1371 		C(PAUSE_ON_TRACE,	"pause-on-trace"),	\
1372 		C(HASH_PTR,		"hash-ptr"),	/* Print hashed pointer */ \
1373 		FUNCTION_FLAGS					\
1374 		FGRAPH_FLAGS					\
1375 		STACK_FLAGS					\
1376 		BRANCH_FLAGS
1377 
1378 /*
1379  * By defining C, we can make TRACE_FLAGS a list of bit names
1380  * that will define the bits for the flag masks.
1381  */
1382 #undef C
1383 #define C(a, b) TRACE_ITER_##a##_BIT
1384 
1385 enum trace_iterator_bits {
1386 	TRACE_FLAGS
1387 	/* Make sure we don't go more than we have bits for */
1388 	TRACE_ITER_LAST_BIT
1389 };
1390 
1391 /*
1392  * By redefining C, we can make TRACE_FLAGS a list of masks that
1393  * use the bits as defined above.
1394  */
1395 #undef C
1396 #define C(a, b) TRACE_ITER_##a = (1 << TRACE_ITER_##a##_BIT)
1397 
1398 enum trace_iterator_flags { TRACE_FLAGS };
1399 
1400 /*
1401  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
1402  * control the output of kernel symbols.
1403  */
1404 #define TRACE_ITER_SYM_MASK \
1405 	(TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
1406 
1407 extern struct tracer nop_trace;
1408 
1409 #ifdef CONFIG_BRANCH_TRACER
1410 extern int enable_branch_tracing(struct trace_array *tr);
1411 extern void disable_branch_tracing(void);
trace_branch_enable(struct trace_array * tr)1412 static inline int trace_branch_enable(struct trace_array *tr)
1413 {
1414 	if (tr->trace_flags & TRACE_ITER_BRANCH)
1415 		return enable_branch_tracing(tr);
1416 	return 0;
1417 }
trace_branch_disable(void)1418 static inline void trace_branch_disable(void)
1419 {
1420 	/* due to races, always disable */
1421 	disable_branch_tracing();
1422 }
1423 #else
trace_branch_enable(struct trace_array * tr)1424 static inline int trace_branch_enable(struct trace_array *tr)
1425 {
1426 	return 0;
1427 }
trace_branch_disable(void)1428 static inline void trace_branch_disable(void)
1429 {
1430 }
1431 #endif /* CONFIG_BRANCH_TRACER */
1432 
1433 /* set ring buffers to default size if not already done so */
1434 int tracing_update_buffers(struct trace_array *tr);
1435 
1436 union trace_synth_field {
1437 	u8				as_u8;
1438 	u16				as_u16;
1439 	u32				as_u32;
1440 	u64				as_u64;
1441 	struct trace_dynamic_info	as_dynamic;
1442 };
1443 
1444 struct ftrace_event_field {
1445 	struct list_head	link;
1446 	const char		*name;
1447 	const char		*type;
1448 	int			filter_type;
1449 	int			offset;
1450 	int			size;
1451 	unsigned int		is_signed:1;
1452 	unsigned int		needs_test:1;
1453 	int			len;
1454 };
1455 
1456 struct prog_entry;
1457 
1458 struct event_filter {
1459 	struct prog_entry __rcu	*prog;
1460 	char			*filter_string;
1461 };
1462 
1463 struct event_subsystem {
1464 	struct list_head	list;
1465 	const char		*name;
1466 	struct event_filter	*filter;
1467 	int			ref_count;
1468 };
1469 
1470 struct trace_subsystem_dir {
1471 	struct list_head		list;
1472 	struct event_subsystem		*subsystem;
1473 	struct trace_array		*tr;
1474 	struct eventfs_inode		*ei;
1475 	int				ref_count;
1476 	int				nr_events;
1477 };
1478 
1479 void trace_buffer_unlock_commit_regs(struct trace_array *tr,
1480 				     struct trace_buffer *buffer,
1481 				     struct ring_buffer_event *event,
1482 				     unsigned int trcace_ctx,
1483 				     struct pt_regs *regs);
1484 
trace_buffer_unlock_commit(struct trace_array * tr,struct trace_buffer * buffer,struct ring_buffer_event * event,unsigned int trace_ctx)1485 static inline void trace_buffer_unlock_commit(struct trace_array *tr,
1486 					      struct trace_buffer *buffer,
1487 					      struct ring_buffer_event *event,
1488 					      unsigned int trace_ctx)
1489 {
1490 	trace_buffer_unlock_commit_regs(tr, buffer, event, trace_ctx, NULL);
1491 }
1492 
1493 DECLARE_PER_CPU(bool, trace_taskinfo_save);
1494 int trace_save_cmdline(struct task_struct *tsk);
1495 int trace_create_savedcmd(void);
1496 int trace_alloc_tgid_map(void);
1497 void trace_free_saved_cmdlines_buffer(void);
1498 
1499 extern const struct file_operations tracing_saved_cmdlines_fops;
1500 extern const struct file_operations tracing_saved_tgids_fops;
1501 extern const struct file_operations tracing_saved_cmdlines_size_fops;
1502 
1503 DECLARE_PER_CPU(struct ring_buffer_event *, trace_buffered_event);
1504 DECLARE_PER_CPU(int, trace_buffered_event_cnt);
1505 void trace_buffered_event_disable(void);
1506 void trace_buffered_event_enable(void);
1507 
1508 void early_enable_events(struct trace_array *tr, char *buf, bool disable_first);
1509 
1510 static inline void
__trace_event_discard_commit(struct trace_buffer * buffer,struct ring_buffer_event * event)1511 __trace_event_discard_commit(struct trace_buffer *buffer,
1512 			     struct ring_buffer_event *event)
1513 {
1514 	if (this_cpu_read(trace_buffered_event) == event) {
1515 		/* Simply release the temp buffer and enable preemption */
1516 		this_cpu_dec(trace_buffered_event_cnt);
1517 		preempt_enable_notrace();
1518 		return;
1519 	}
1520 	/* ring_buffer_discard_commit() enables preemption */
1521 	ring_buffer_discard_commit(buffer, event);
1522 }
1523 
1524 /*
1525  * Helper function for event_trigger_unlock_commit{_regs}().
1526  * If there are event triggers attached to this event that requires
1527  * filtering against its fields, then they will be called as the
1528  * entry already holds the field information of the current event.
1529  *
1530  * It also checks if the event should be discarded or not.
1531  * It is to be discarded if the event is soft disabled and the
1532  * event was only recorded to process triggers, or if the event
1533  * filter is active and this event did not match the filters.
1534  *
1535  * Returns true if the event is discarded, false otherwise.
1536  */
1537 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)1538 __event_trigger_test_discard(struct trace_event_file *file,
1539 			     struct trace_buffer *buffer,
1540 			     struct ring_buffer_event *event,
1541 			     void *entry,
1542 			     enum event_trigger_type *tt)
1543 {
1544 	unsigned long eflags = file->flags;
1545 
1546 	if (eflags & EVENT_FILE_FL_TRIGGER_COND)
1547 		*tt = event_triggers_call(file, buffer, entry, event);
1548 
1549 	if (likely(!(file->flags & (EVENT_FILE_FL_SOFT_DISABLED |
1550 				    EVENT_FILE_FL_FILTERED |
1551 				    EVENT_FILE_FL_PID_FILTER))))
1552 		return false;
1553 
1554 	if (file->flags & EVENT_FILE_FL_SOFT_DISABLED)
1555 		goto discard;
1556 
1557 	if (file->flags & EVENT_FILE_FL_FILTERED &&
1558 	    !filter_match_preds(file->filter, entry))
1559 		goto discard;
1560 
1561 	if ((file->flags & EVENT_FILE_FL_PID_FILTER) &&
1562 	    trace_event_ignore_this_pid(file))
1563 		goto discard;
1564 
1565 	return false;
1566  discard:
1567 	__trace_event_discard_commit(buffer, event);
1568 	return true;
1569 }
1570 
1571 /**
1572  * event_trigger_unlock_commit - handle triggers and finish event commit
1573  * @file: The file pointer associated with the event
1574  * @buffer: The ring buffer that the event is being written to
1575  * @event: The event meta data in the ring buffer
1576  * @entry: The event itself
1577  * @trace_ctx: The tracing context flags.
1578  *
1579  * This is a helper function to handle triggers that require data
1580  * from the event itself. It also tests the event against filters and
1581  * if the event is soft disabled and should be discarded.
1582  */
1583 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)1584 event_trigger_unlock_commit(struct trace_event_file *file,
1585 			    struct trace_buffer *buffer,
1586 			    struct ring_buffer_event *event,
1587 			    void *entry, unsigned int trace_ctx)
1588 {
1589 	enum event_trigger_type tt = ETT_NONE;
1590 
1591 	if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1592 		trace_buffer_unlock_commit(file->tr, buffer, event, trace_ctx);
1593 
1594 	if (tt)
1595 		event_triggers_post_call(file, tt);
1596 }
1597 
1598 #define FILTER_PRED_INVALID	((unsigned short)-1)
1599 #define FILTER_PRED_IS_RIGHT	(1 << 15)
1600 #define FILTER_PRED_FOLD	(1 << 15)
1601 
1602 /*
1603  * The max preds is the size of unsigned short with
1604  * two flags at the MSBs. One bit is used for both the IS_RIGHT
1605  * and FOLD flags. The other is reserved.
1606  *
1607  * 2^14 preds is way more than enough.
1608  */
1609 #define MAX_FILTER_PRED		16384
1610 
1611 struct filter_pred;
1612 struct regex;
1613 
1614 typedef int (*regex_match_func)(char *str, struct regex *r, int len);
1615 
1616 enum regex_type {
1617 	MATCH_FULL = 0,
1618 	MATCH_FRONT_ONLY,
1619 	MATCH_MIDDLE_ONLY,
1620 	MATCH_END_ONLY,
1621 	MATCH_GLOB,
1622 	MATCH_INDEX,
1623 };
1624 
1625 struct regex {
1626 	char			pattern[MAX_FILTER_STR_VAL];
1627 	int			len;
1628 	int			field_len;
1629 	regex_match_func	match;
1630 };
1631 
is_string_field(struct ftrace_event_field * field)1632 static inline bool is_string_field(struct ftrace_event_field *field)
1633 {
1634 	return field->filter_type == FILTER_DYN_STRING ||
1635 	       field->filter_type == FILTER_RDYN_STRING ||
1636 	       field->filter_type == FILTER_STATIC_STRING ||
1637 	       field->filter_type == FILTER_PTR_STRING ||
1638 	       field->filter_type == FILTER_COMM;
1639 }
1640 
is_function_field(struct ftrace_event_field * field)1641 static inline bool is_function_field(struct ftrace_event_field *field)
1642 {
1643 	return field->filter_type == FILTER_TRACE_FN;
1644 }
1645 
1646 extern enum regex_type
1647 filter_parse_regex(char *buff, int len, char **search, int *not);
1648 extern void print_event_filter(struct trace_event_file *file,
1649 			       struct trace_seq *s);
1650 extern int apply_event_filter(struct trace_event_file *file,
1651 			      char *filter_string);
1652 extern int apply_subsystem_event_filter(struct trace_subsystem_dir *dir,
1653 					char *filter_string);
1654 extern void print_subsystem_event_filter(struct event_subsystem *system,
1655 					 struct trace_seq *s);
1656 extern int filter_assign_type(const char *type);
1657 extern int create_event_filter(struct trace_array *tr,
1658 			       struct trace_event_call *call,
1659 			       char *filter_str, bool set_str,
1660 			       struct event_filter **filterp);
1661 extern void free_event_filter(struct event_filter *filter);
1662 
1663 struct ftrace_event_field *
1664 trace_find_event_field(struct trace_event_call *call, char *name);
1665 
1666 extern void trace_event_enable_cmd_record(bool enable);
1667 extern void trace_event_enable_tgid_record(bool enable);
1668 
1669 extern int event_trace_init(void);
1670 extern int init_events(void);
1671 extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
1672 extern int event_trace_del_tracer(struct trace_array *tr);
1673 extern void __trace_early_add_events(struct trace_array *tr);
1674 
1675 extern struct trace_event_file *__find_event_file(struct trace_array *tr,
1676 						  const char *system,
1677 						  const char *event);
1678 extern struct trace_event_file *find_event_file(struct trace_array *tr,
1679 						const char *system,
1680 						const char *event);
1681 
event_file_data(struct file * filp)1682 static inline void *event_file_data(struct file *filp)
1683 {
1684 	return READ_ONCE(file_inode(filp)->i_private);
1685 }
1686 
1687 extern struct mutex event_mutex;
1688 extern struct list_head ftrace_events;
1689 
1690 /*
1691  * When the trace_event_file is the filp->i_private pointer,
1692  * it must be taken under the event_mutex lock, and then checked
1693  * if the EVENT_FILE_FL_FREED flag is set. If it is, then the
1694  * data pointed to by the trace_event_file can not be trusted.
1695  *
1696  * Use the event_file_file() to access the trace_event_file from
1697  * the filp the first time under the event_mutex and check for
1698  * NULL. If it is needed to be retrieved again and the event_mutex
1699  * is still held, then the event_file_data() can be used and it
1700  * is guaranteed to be valid.
1701  */
event_file_file(struct file * filp)1702 static inline struct trace_event_file *event_file_file(struct file *filp)
1703 {
1704 	struct trace_event_file *file;
1705 
1706 	lockdep_assert_held(&event_mutex);
1707 	file = READ_ONCE(file_inode(filp)->i_private);
1708 	if (!file || file->flags & EVENT_FILE_FL_FREED)
1709 		return NULL;
1710 	return file;
1711 }
1712 
1713 extern const struct file_operations event_trigger_fops;
1714 extern const struct file_operations event_hist_fops;
1715 extern const struct file_operations event_hist_debug_fops;
1716 extern const struct file_operations event_inject_fops;
1717 
1718 #ifdef CONFIG_HIST_TRIGGERS
1719 extern int register_trigger_hist_cmd(void);
1720 extern int register_trigger_hist_enable_disable_cmds(void);
1721 #else
register_trigger_hist_cmd(void)1722 static inline int register_trigger_hist_cmd(void) { return 0; }
register_trigger_hist_enable_disable_cmds(void)1723 static inline int register_trigger_hist_enable_disable_cmds(void) { return 0; }
1724 #endif
1725 
1726 extern int register_trigger_cmds(void);
1727 extern void clear_event_triggers(struct trace_array *tr);
1728 
1729 enum {
1730 	EVENT_TRIGGER_FL_PROBE		= BIT(0),
1731 };
1732 
1733 struct event_trigger_data {
1734 	unsigned long			count;
1735 	int				ref;
1736 	int				flags;
1737 	const struct event_trigger_ops	*ops;
1738 	struct event_command		*cmd_ops;
1739 	struct event_filter __rcu	*filter;
1740 	char				*filter_str;
1741 	void				*private_data;
1742 	bool				paused;
1743 	bool				paused_tmp;
1744 	struct list_head		list;
1745 	char				*name;
1746 	struct list_head		named_list;
1747 	struct event_trigger_data	*named_data;
1748 };
1749 
1750 /* Avoid typos */
1751 #define ENABLE_EVENT_STR	"enable_event"
1752 #define DISABLE_EVENT_STR	"disable_event"
1753 #define ENABLE_HIST_STR		"enable_hist"
1754 #define DISABLE_HIST_STR	"disable_hist"
1755 
1756 struct enable_trigger_data {
1757 	struct trace_event_file		*file;
1758 	bool				enable;
1759 	bool				hist;
1760 };
1761 
1762 extern int event_enable_trigger_print(struct seq_file *m,
1763 				      struct event_trigger_data *data);
1764 extern void event_enable_trigger_free(struct event_trigger_data *data);
1765 extern int event_enable_trigger_parse(struct event_command *cmd_ops,
1766 				      struct trace_event_file *file,
1767 				      char *glob, char *cmd,
1768 				      char *param_and_filter);
1769 extern int event_enable_register_trigger(char *glob,
1770 					 struct event_trigger_data *data,
1771 					 struct trace_event_file *file);
1772 extern void event_enable_unregister_trigger(char *glob,
1773 					    struct event_trigger_data *test,
1774 					    struct trace_event_file *file);
1775 extern void trigger_data_free(struct event_trigger_data *data);
1776 extern int event_trigger_init(struct event_trigger_data *data);
1777 extern int trace_event_trigger_enable_disable(struct trace_event_file *file,
1778 					      int trigger_enable);
1779 extern void update_cond_flag(struct trace_event_file *file);
1780 extern int set_trigger_filter(char *filter_str,
1781 			      struct event_trigger_data *trigger_data,
1782 			      struct trace_event_file *file);
1783 extern struct event_trigger_data *find_named_trigger(const char *name);
1784 extern bool is_named_trigger(struct event_trigger_data *test);
1785 extern int save_named_trigger(const char *name,
1786 			      struct event_trigger_data *data);
1787 extern void del_named_trigger(struct event_trigger_data *data);
1788 extern void pause_named_trigger(struct event_trigger_data *data);
1789 extern void unpause_named_trigger(struct event_trigger_data *data);
1790 extern void set_named_trigger_data(struct event_trigger_data *data,
1791 				   struct event_trigger_data *named_data);
1792 extern struct event_trigger_data *
1793 get_named_trigger_data(struct event_trigger_data *data);
1794 extern int register_event_command(struct event_command *cmd);
1795 extern int unregister_event_command(struct event_command *cmd);
1796 extern int register_trigger_hist_enable_disable_cmds(void);
1797 extern bool event_trigger_check_remove(const char *glob);
1798 extern bool event_trigger_empty_param(const char *param);
1799 extern int event_trigger_separate_filter(char *param_and_filter, char **param,
1800 					 char **filter, bool param_required);
1801 extern struct event_trigger_data *
1802 event_trigger_alloc(struct event_command *cmd_ops,
1803 		    char *cmd,
1804 		    char *param,
1805 		    void *private_data);
1806 extern int event_trigger_parse_num(char *trigger,
1807 				   struct event_trigger_data *trigger_data);
1808 extern int event_trigger_set_filter(struct event_command *cmd_ops,
1809 				    struct trace_event_file *file,
1810 				    char *param,
1811 				    struct event_trigger_data *trigger_data);
1812 extern void event_trigger_reset_filter(struct event_command *cmd_ops,
1813 				       struct event_trigger_data *trigger_data);
1814 extern int event_trigger_register(struct event_command *cmd_ops,
1815 				  struct trace_event_file *file,
1816 				  char *glob,
1817 				  struct event_trigger_data *trigger_data);
1818 extern void event_trigger_unregister(struct event_command *cmd_ops,
1819 				     struct trace_event_file *file,
1820 				     char *glob,
1821 				     struct event_trigger_data *trigger_data);
1822 
1823 extern void event_file_get(struct trace_event_file *file);
1824 extern void event_file_put(struct trace_event_file *file);
1825 
1826 /**
1827  * struct event_trigger_ops - callbacks for trace event triggers
1828  *
1829  * The methods in this structure provide per-event trigger hooks for
1830  * various trigger operations.
1831  *
1832  * The @init and @free methods are used during trigger setup and
1833  * teardown, typically called from an event_command's @parse()
1834  * function implementation.
1835  *
1836  * The @print method is used to print the trigger spec.
1837  *
1838  * The @trigger method is the function that actually implements the
1839  * trigger and is called in the context of the triggering event
1840  * whenever that event occurs.
1841  *
1842  * All the methods below, except for @init() and @free(), must be
1843  * implemented.
1844  *
1845  * @trigger: The trigger 'probe' function called when the triggering
1846  *	event occurs.  The data passed into this callback is the data
1847  *	that was supplied to the event_command @reg() function that
1848  *	registered the trigger (see struct event_command) along with
1849  *	the trace record, rec.
1850  *
1851  * @init: An optional initialization function called for the trigger
1852  *	when the trigger is registered (via the event_command reg()
1853  *	function).  This can be used to perform per-trigger
1854  *	initialization such as incrementing a per-trigger reference
1855  *	count, for instance.  This is usually implemented by the
1856  *	generic utility function @event_trigger_init() (see
1857  *	trace_event_triggers.c).
1858  *
1859  * @free: An optional de-initialization function called for the
1860  *	trigger when the trigger is unregistered (via the
1861  *	event_command @reg() function).  This can be used to perform
1862  *	per-trigger de-initialization such as decrementing a
1863  *	per-trigger reference count and freeing corresponding trigger
1864  *	data, for instance.  This is usually implemented by the
1865  *	generic utility function @event_trigger_free() (see
1866  *	trace_event_triggers.c).
1867  *
1868  * @print: The callback function invoked to have the trigger print
1869  *	itself.  This is usually implemented by a wrapper function
1870  *	that calls the generic utility function @event_trigger_print()
1871  *	(see trace_event_triggers.c).
1872  */
1873 struct event_trigger_ops {
1874 	void			(*trigger)(struct event_trigger_data *data,
1875 					   struct trace_buffer *buffer,
1876 					   void *rec,
1877 					   struct ring_buffer_event *rbe);
1878 	int			(*init)(struct event_trigger_data *data);
1879 	void			(*free)(struct event_trigger_data *data);
1880 	int			(*print)(struct seq_file *m,
1881 					 struct event_trigger_data *data);
1882 };
1883 
1884 /**
1885  * struct event_command - callbacks and data members for event commands
1886  *
1887  * Event commands are invoked by users by writing the command name
1888  * into the 'trigger' file associated with a trace event.  The
1889  * parameters associated with a specific invocation of an event
1890  * command are used to create an event trigger instance, which is
1891  * added to the list of trigger instances associated with that trace
1892  * event.  When the event is hit, the set of triggers associated with
1893  * that event is invoked.
1894  *
1895  * The data members in this structure provide per-event command data
1896  * for various event commands.
1897  *
1898  * All the data members below, except for @post_trigger, must be set
1899  * for each event command.
1900  *
1901  * @name: The unique name that identifies the event command.  This is
1902  *	the name used when setting triggers via trigger files.
1903  *
1904  * @trigger_type: A unique id that identifies the event command
1905  *	'type'.  This value has two purposes, the first to ensure that
1906  *	only one trigger of the same type can be set at a given time
1907  *	for a particular event e.g. it doesn't make sense to have both
1908  *	a traceon and traceoff trigger attached to a single event at
1909  *	the same time, so traceon and traceoff have the same type
1910  *	though they have different names.  The @trigger_type value is
1911  *	also used as a bit value for deferring the actual trigger
1912  *	action until after the current event is finished.  Some
1913  *	commands need to do this if they themselves log to the trace
1914  *	buffer (see the @post_trigger() member below).  @trigger_type
1915  *	values are defined by adding new values to the trigger_type
1916  *	enum in include/linux/trace_events.h.
1917  *
1918  * @flags: See the enum event_command_flags below.
1919  *
1920  * All the methods below, except for @set_filter() and @unreg_all(),
1921  * must be implemented.
1922  *
1923  * @parse: The callback function responsible for parsing and
1924  *	registering the trigger written to the 'trigger' file by the
1925  *	user.  It allocates the trigger instance and registers it with
1926  *	the appropriate trace event.  It makes use of the other
1927  *	event_command callback functions to orchestrate this, and is
1928  *	usually implemented by the generic utility function
1929  *	@event_trigger_callback() (see trace_event_triggers.c).
1930  *
1931  * @reg: Adds the trigger to the list of triggers associated with the
1932  *	event, and enables the event trigger itself, after
1933  *	initializing it (via the event_trigger_ops @init() function).
1934  *	This is also where commands can use the @trigger_type value to
1935  *	make the decision as to whether or not multiple instances of
1936  *	the trigger should be allowed.  This is usually implemented by
1937  *	the generic utility function @register_trigger() (see
1938  *	trace_event_triggers.c).
1939  *
1940  * @unreg: Removes the trigger from the list of triggers associated
1941  *	with the event, and disables the event trigger itself, after
1942  *	initializing it (via the event_trigger_ops @free() function).
1943  *	This is usually implemented by the generic utility function
1944  *	@unregister_trigger() (see trace_event_triggers.c).
1945  *
1946  * @unreg_all: An optional function called to remove all the triggers
1947  *	from the list of triggers associated with the event.  Called
1948  *	when a trigger file is opened in truncate mode.
1949  *
1950  * @set_filter: An optional function called to parse and set a filter
1951  *	for the trigger.  If no @set_filter() method is set for the
1952  *	event command, filters set by the user for the command will be
1953  *	ignored.  This is usually implemented by the generic utility
1954  *	function @set_trigger_filter() (see trace_event_triggers.c).
1955  *
1956  * @get_trigger_ops: The callback function invoked to retrieve the
1957  *	event_trigger_ops implementation associated with the command.
1958  *	This callback function allows a single event_command to
1959  *	support multiple trigger implementations via different sets of
1960  *	event_trigger_ops, depending on the value of the @param
1961  *	string.
1962  */
1963 struct event_command {
1964 	struct list_head	list;
1965 	char			*name;
1966 	enum event_trigger_type	trigger_type;
1967 	int			flags;
1968 	int			(*parse)(struct event_command *cmd_ops,
1969 					 struct trace_event_file *file,
1970 					 char *glob, char *cmd,
1971 					 char *param_and_filter);
1972 	int			(*reg)(char *glob,
1973 				       struct event_trigger_data *data,
1974 				       struct trace_event_file *file);
1975 	void			(*unreg)(char *glob,
1976 					 struct event_trigger_data *data,
1977 					 struct trace_event_file *file);
1978 	void			(*unreg_all)(struct trace_event_file *file);
1979 	int			(*set_filter)(char *filter_str,
1980 					      struct event_trigger_data *data,
1981 					      struct trace_event_file *file);
1982 	const struct event_trigger_ops *(*get_trigger_ops)(char *cmd, char *param);
1983 };
1984 
1985 /**
1986  * enum event_command_flags - flags for struct event_command
1987  *
1988  * @POST_TRIGGER: A flag that says whether or not this command needs
1989  *	to have its action delayed until after the current event has
1990  *	been closed.  Some triggers need to avoid being invoked while
1991  *	an event is currently in the process of being logged, since
1992  *	the trigger may itself log data into the trace buffer.  Thus
1993  *	we make sure the current event is committed before invoking
1994  *	those triggers.  To do that, the trigger invocation is split
1995  *	in two - the first part checks the filter using the current
1996  *	trace record; if a command has the @post_trigger flag set, it
1997  *	sets a bit for itself in the return value, otherwise it
1998  *	directly invokes the trigger.  Once all commands have been
1999  *	either invoked or set their return flag, the current record is
2000  *	either committed or discarded.  At that point, if any commands
2001  *	have deferred their triggers, those commands are finally
2002  *	invoked following the close of the current event.  In other
2003  *	words, if the event_trigger_ops @func() probe implementation
2004  *	itself logs to the trace buffer, this flag should be set,
2005  *	otherwise it can be left unspecified.
2006  *
2007  * @NEEDS_REC: A flag that says whether or not this command needs
2008  *	access to the trace record in order to perform its function,
2009  *	regardless of whether or not it has a filter associated with
2010  *	it (filters make a trigger require access to the trace record
2011  *	but are not always present).
2012  */
2013 enum event_command_flags {
2014 	EVENT_CMD_FL_POST_TRIGGER	= 1,
2015 	EVENT_CMD_FL_NEEDS_REC		= 2,
2016 };
2017 
event_command_post_trigger(struct event_command * cmd_ops)2018 static inline bool event_command_post_trigger(struct event_command *cmd_ops)
2019 {
2020 	return cmd_ops->flags & EVENT_CMD_FL_POST_TRIGGER;
2021 }
2022 
event_command_needs_rec(struct event_command * cmd_ops)2023 static inline bool event_command_needs_rec(struct event_command *cmd_ops)
2024 {
2025 	return cmd_ops->flags & EVENT_CMD_FL_NEEDS_REC;
2026 }
2027 
2028 extern int trace_event_enable_disable(struct trace_event_file *file,
2029 				      int enable, int soft_disable);
2030 extern int tracing_alloc_snapshot(void);
2031 extern void tracing_snapshot_cond(struct trace_array *tr, void *cond_data);
2032 extern int tracing_snapshot_cond_enable(struct trace_array *tr, void *cond_data, cond_update_fn_t update);
2033 
2034 extern int tracing_snapshot_cond_disable(struct trace_array *tr);
2035 extern void *tracing_cond_snapshot_data(struct trace_array *tr);
2036 
2037 extern const char *__start___trace_bprintk_fmt[];
2038 extern const char *__stop___trace_bprintk_fmt[];
2039 
2040 extern const char *__start___tracepoint_str[];
2041 extern const char *__stop___tracepoint_str[];
2042 
2043 void trace_printk_control(bool enabled);
2044 void trace_printk_start_comm(void);
2045 int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set);
2046 int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled);
2047 
2048 /* Used from boot time tracer */
2049 extern int trace_set_options(struct trace_array *tr, char *option);
2050 extern int tracing_set_tracer(struct trace_array *tr, const char *buf);
2051 extern ssize_t tracing_resize_ring_buffer(struct trace_array *tr,
2052 					  unsigned long size, int cpu_id);
2053 extern int tracing_set_cpumask(struct trace_array *tr,
2054 				cpumask_var_t tracing_cpumask_new);
2055 
2056 
2057 #define MAX_EVENT_NAME_LEN	64
2058 
2059 extern ssize_t trace_parse_run_command(struct file *file,
2060 		const char __user *buffer, size_t count, loff_t *ppos,
2061 		int (*createfn)(const char *));
2062 
2063 extern unsigned int err_pos(char *cmd, const char *str);
2064 extern void tracing_log_err(struct trace_array *tr,
2065 			    const char *loc, const char *cmd,
2066 			    const char **errs, u8 type, u16 pos);
2067 
2068 /*
2069  * Normal trace_printk() and friends allocates special buffers
2070  * to do the manipulation, as well as saves the print formats
2071  * into sections to display. But the trace infrastructure wants
2072  * to use these without the added overhead at the price of being
2073  * a bit slower (used mainly for warnings, where we don't care
2074  * about performance). The internal_trace_puts() is for such
2075  * a purpose.
2076  */
2077 #define internal_trace_puts(str) __trace_puts(_THIS_IP_, str, strlen(str))
2078 
2079 #undef FTRACE_ENTRY
2080 #define FTRACE_ENTRY(call, struct_name, id, tstruct, print)	\
2081 	extern struct trace_event_call					\
2082 	__aligned(4) event_##call;
2083 #undef FTRACE_ENTRY_DUP
2084 #define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print)	\
2085 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
2086 #undef FTRACE_ENTRY_PACKED
2087 #define FTRACE_ENTRY_PACKED(call, struct_name, id, tstruct, print) \
2088 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
2089 
2090 #include "trace_entries.h"
2091 
2092 #if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_FUNCTION_TRACER)
2093 int perf_ftrace_event_register(struct trace_event_call *call,
2094 			       enum trace_reg type, void *data);
2095 #else
2096 #define perf_ftrace_event_register NULL
2097 #endif
2098 
2099 #ifdef CONFIG_FTRACE_SYSCALLS
2100 void init_ftrace_syscalls(void);
2101 const char *get_syscall_name(int syscall);
2102 #else
init_ftrace_syscalls(void)2103 static inline void init_ftrace_syscalls(void) { }
get_syscall_name(int syscall)2104 static inline const char *get_syscall_name(int syscall)
2105 {
2106 	return NULL;
2107 }
2108 #endif
2109 
2110 #ifdef CONFIG_EVENT_TRACING
2111 void trace_event_init(void);
2112 void trace_event_eval_update(struct trace_eval_map **map, int len);
2113 /* Used from boot time tracer */
2114 extern int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set);
2115 extern int trigger_process_regex(struct trace_event_file *file, char *buff);
2116 #else
trace_event_init(void)2117 static inline void __init trace_event_init(void) { }
trace_event_eval_update(struct trace_eval_map ** map,int len)2118 static inline void trace_event_eval_update(struct trace_eval_map **map, int len) { }
2119 #endif
2120 
2121 #ifdef CONFIG_TRACER_SNAPSHOT
2122 void tracing_snapshot_instance(struct trace_array *tr);
2123 int tracing_alloc_snapshot_instance(struct trace_array *tr);
2124 int tracing_arm_snapshot(struct trace_array *tr);
2125 void tracing_disarm_snapshot(struct trace_array *tr);
2126 #else
tracing_snapshot_instance(struct trace_array * tr)2127 static inline void tracing_snapshot_instance(struct trace_array *tr) { }
tracing_alloc_snapshot_instance(struct trace_array * tr)2128 static inline int tracing_alloc_snapshot_instance(struct trace_array *tr)
2129 {
2130 	return 0;
2131 }
tracing_arm_snapshot(struct trace_array * tr)2132 static inline int tracing_arm_snapshot(struct trace_array *tr) { return 0; }
tracing_disarm_snapshot(struct trace_array * tr)2133 static inline void tracing_disarm_snapshot(struct trace_array *tr) { }
2134 #endif
2135 
2136 #ifdef CONFIG_PREEMPT_TRACER
2137 void tracer_preempt_on(unsigned long a0, unsigned long a1);
2138 void tracer_preempt_off(unsigned long a0, unsigned long a1);
2139 #else
tracer_preempt_on(unsigned long a0,unsigned long a1)2140 static inline void tracer_preempt_on(unsigned long a0, unsigned long a1) { }
tracer_preempt_off(unsigned long a0,unsigned long a1)2141 static inline void tracer_preempt_off(unsigned long a0, unsigned long a1) { }
2142 #endif
2143 #ifdef CONFIG_IRQSOFF_TRACER
2144 void tracer_hardirqs_on(unsigned long a0, unsigned long a1);
2145 void tracer_hardirqs_off(unsigned long a0, unsigned long a1);
2146 #else
tracer_hardirqs_on(unsigned long a0,unsigned long a1)2147 static inline void tracer_hardirqs_on(unsigned long a0, unsigned long a1) { }
tracer_hardirqs_off(unsigned long a0,unsigned long a1)2148 static inline void tracer_hardirqs_off(unsigned long a0, unsigned long a1) { }
2149 #endif
2150 
2151 /*
2152  * Reset the state of the trace_iterator so that it can read consumed data.
2153  * Normally, the trace_iterator is used for reading the data when it is not
2154  * consumed, and must retain state.
2155  */
trace_iterator_reset(struct trace_iterator * iter)2156 static __always_inline void trace_iterator_reset(struct trace_iterator *iter)
2157 {
2158 	memset_startat(iter, 0, seq);
2159 	iter->pos = -1;
2160 }
2161 
2162 /* Check the name is good for event/group/fields */
__is_good_name(const char * name,bool hash_ok)2163 static inline bool __is_good_name(const char *name, bool hash_ok)
2164 {
2165 	if (!isalpha(*name) && *name != '_' && (!hash_ok || *name != '-'))
2166 		return false;
2167 	while (*++name != '\0') {
2168 		if (!isalpha(*name) && !isdigit(*name) && *name != '_' &&
2169 		    (!hash_ok || *name != '-'))
2170 			return false;
2171 	}
2172 	return true;
2173 }
2174 
2175 /* Check the name is good for event/group/fields */
is_good_name(const char * name)2176 static inline bool is_good_name(const char *name)
2177 {
2178 	return __is_good_name(name, false);
2179 }
2180 
2181 /* Check the name is good for system */
is_good_system_name(const char * name)2182 static inline bool is_good_system_name(const char *name)
2183 {
2184 	return __is_good_name(name, true);
2185 }
2186 
2187 /* Convert certain expected symbols into '_' when generating event names */
sanitize_event_name(char * name)2188 static inline void sanitize_event_name(char *name)
2189 {
2190 	while (*name++ != '\0')
2191 		if (*name == ':' || *name == '.')
2192 			*name = '_';
2193 }
2194 
2195 /*
2196  * This is a generic way to read and write a u64 value from a file in tracefs.
2197  *
2198  * The value is stored on the variable pointed by *val. The value needs
2199  * to be at least *min and at most *max. The write is protected by an
2200  * existing *lock.
2201  */
2202 struct trace_min_max_param {
2203 	struct mutex	*lock;
2204 	u64		*val;
2205 	u64		*min;
2206 	u64		*max;
2207 };
2208 
2209 #define U64_STR_SIZE		24	/* 20 digits max */
2210 
2211 extern const struct file_operations trace_min_max_fops;
2212 
2213 #ifdef CONFIG_RV
2214 extern int rv_init_interface(void);
2215 #else
rv_init_interface(void)2216 static inline int rv_init_interface(void)
2217 {
2218 	return 0;
2219 }
2220 #endif
2221 
2222 /*
2223  * This is used only to distinguish
2224  * function address from trampoline code.
2225  * So this value has no meaning.
2226  */
2227 #define FTRACE_TRAMPOLINE_MARKER  ((unsigned long) INT_MAX)
2228 
2229 #endif /* _LINUX_KERNEL_TRACE_H */
2230