xref: /openbmc/linux/kernel/trace/trace.h (revision b37c3848)
1 // SPDX-License-Identifier: GPL-2.0
2 
3 #ifndef _LINUX_KERNEL_TRACE_H
4 #define _LINUX_KERNEL_TRACE_H
5 
6 #include <linux/fs.h>
7 #include <linux/atomic.h>
8 #include <linux/sched.h>
9 #include <linux/clocksource.h>
10 #include <linux/ring_buffer.h>
11 #include <linux/mmiotrace.h>
12 #include <linux/tracepoint.h>
13 #include <linux/ftrace.h>
14 #include <linux/trace.h>
15 #include <linux/hw_breakpoint.h>
16 #include <linux/trace_seq.h>
17 #include <linux/trace_events.h>
18 #include <linux/compiler.h>
19 #include <linux/glob.h>
20 #include <linux/irq_work.h>
21 #include <linux/workqueue.h>
22 #include <linux/ctype.h>
23 
24 #ifdef CONFIG_FTRACE_SYSCALLS
25 #include <asm/unistd.h>		/* For NR_SYSCALLS	     */
26 #include <asm/syscall.h>	/* some archs define it here */
27 #endif
28 
29 enum trace_type {
30 	__TRACE_FIRST_TYPE = 0,
31 
32 	TRACE_FN,
33 	TRACE_CTX,
34 	TRACE_WAKE,
35 	TRACE_STACK,
36 	TRACE_PRINT,
37 	TRACE_BPRINT,
38 	TRACE_MMIO_RW,
39 	TRACE_MMIO_MAP,
40 	TRACE_BRANCH,
41 	TRACE_GRAPH_RET,
42 	TRACE_GRAPH_ENT,
43 	TRACE_USER_STACK,
44 	TRACE_BLK,
45 	TRACE_BPUTS,
46 	TRACE_HWLAT,
47 	TRACE_RAW_DATA,
48 
49 	__TRACE_LAST_TYPE,
50 };
51 
52 
53 #undef __field
54 #define __field(type, item)		type	item;
55 
56 #undef __field_fn
57 #define __field_fn(type, item)		type	item;
58 
59 #undef __field_struct
60 #define __field_struct(type, item)	__field(type, item)
61 
62 #undef __field_desc
63 #define __field_desc(type, container, item)
64 
65 #undef __field_packed
66 #define __field_packed(type, container, item)
67 
68 #undef __array
69 #define __array(type, item, size)	type	item[size];
70 
71 #undef __array_desc
72 #define __array_desc(type, container, item, size)
73 
74 #undef __dynamic_array
75 #define __dynamic_array(type, item)	type	item[];
76 
77 #undef F_STRUCT
78 #define F_STRUCT(args...)		args
79 
80 #undef FTRACE_ENTRY
81 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print)		\
82 	struct struct_name {						\
83 		struct trace_entry	ent;				\
84 		tstruct							\
85 	}
86 
87 #undef FTRACE_ENTRY_DUP
88 #define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk)
89 
90 #undef FTRACE_ENTRY_REG
91 #define FTRACE_ENTRY_REG(name, struct_name, id, tstruct, print,	regfn)	\
92 	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print))
93 
94 #undef FTRACE_ENTRY_PACKED
95 #define FTRACE_ENTRY_PACKED(name, struct_name, id, tstruct, print)	\
96 	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print)) __packed
97 
98 #include "trace_entries.h"
99 
100 /* Use this for memory failure errors */
101 #define MEM_FAIL(condition, fmt, ...) ({			\
102 	static bool __section(".data.once") __warned;		\
103 	int __ret_warn_once = !!(condition);			\
104 								\
105 	if (unlikely(__ret_warn_once && !__warned)) {		\
106 		__warned = true;				\
107 		pr_err("ERROR: " fmt, ##__VA_ARGS__);		\
108 	}							\
109 	unlikely(__ret_warn_once);				\
110 })
111 
112 /*
113  * syscalls are special, and need special handling, this is why
114  * they are not included in trace_entries.h
115  */
116 struct syscall_trace_enter {
117 	struct trace_entry	ent;
118 	int			nr;
119 	unsigned long		args[];
120 };
121 
122 struct syscall_trace_exit {
123 	struct trace_entry	ent;
124 	int			nr;
125 	long			ret;
126 };
127 
128 struct kprobe_trace_entry_head {
129 	struct trace_entry	ent;
130 	unsigned long		ip;
131 };
132 
133 struct kretprobe_trace_entry_head {
134 	struct trace_entry	ent;
135 	unsigned long		func;
136 	unsigned long		ret_ip;
137 };
138 
139 #define TRACE_BUF_SIZE		1024
140 
141 struct trace_array;
142 
143 /*
144  * The CPU trace array - it consists of thousands of trace entries
145  * plus some other descriptor data: (for example which task started
146  * the trace, etc.)
147  */
148 struct trace_array_cpu {
149 	atomic_t		disabled;
150 	void			*buffer_page;	/* ring buffer spare */
151 
152 	unsigned long		entries;
153 	unsigned long		saved_latency;
154 	unsigned long		critical_start;
155 	unsigned long		critical_end;
156 	unsigned long		critical_sequence;
157 	unsigned long		nice;
158 	unsigned long		policy;
159 	unsigned long		rt_priority;
160 	unsigned long		skipped_entries;
161 	u64			preempt_timestamp;
162 	pid_t			pid;
163 	kuid_t			uid;
164 	char			comm[TASK_COMM_LEN];
165 
166 #ifdef CONFIG_FUNCTION_TRACER
167 	int			ftrace_ignore_pid;
168 #endif
169 	bool			ignore_pid;
170 };
171 
172 struct tracer;
173 struct trace_option_dentry;
174 
175 struct array_buffer {
176 	struct trace_array		*tr;
177 	struct trace_buffer		*buffer;
178 	struct trace_array_cpu __percpu	*data;
179 	u64				time_start;
180 	int				cpu;
181 };
182 
183 #define TRACE_FLAGS_MAX_SIZE		32
184 
185 struct trace_options {
186 	struct tracer			*tracer;
187 	struct trace_option_dentry	*topts;
188 };
189 
190 struct trace_pid_list {
191 	int				pid_max;
192 	unsigned long			*pids;
193 };
194 
195 enum {
196 	TRACE_PIDS		= BIT(0),
197 	TRACE_NO_PIDS		= BIT(1),
198 };
199 
200 static inline bool pid_type_enabled(int type, struct trace_pid_list *pid_list,
201 				    struct trace_pid_list *no_pid_list)
202 {
203 	/* Return true if the pid list in type has pids */
204 	return ((type & TRACE_PIDS) && pid_list) ||
205 		((type & TRACE_NO_PIDS) && no_pid_list);
206 }
207 
208 static inline bool still_need_pid_events(int type, struct trace_pid_list *pid_list,
209 					 struct trace_pid_list *no_pid_list)
210 {
211 	/*
212 	 * Turning off what is in @type, return true if the "other"
213 	 * pid list, still has pids in it.
214 	 */
215 	return (!(type & TRACE_PIDS) && pid_list) ||
216 		(!(type & TRACE_NO_PIDS) && no_pid_list);
217 }
218 
219 typedef bool (*cond_update_fn_t)(struct trace_array *tr, void *cond_data);
220 
221 /**
222  * struct cond_snapshot - conditional snapshot data and callback
223  *
224  * The cond_snapshot structure encapsulates a callback function and
225  * data associated with the snapshot for a given tracing instance.
226  *
227  * When a snapshot is taken conditionally, by invoking
228  * tracing_snapshot_cond(tr, cond_data), the cond_data passed in is
229  * passed in turn to the cond_snapshot.update() function.  That data
230  * can be compared by the update() implementation with the cond_data
231  * contained within the struct cond_snapshot instance associated with
232  * the trace_array.  Because the tr->max_lock is held throughout the
233  * update() call, the update() function can directly retrieve the
234  * cond_snapshot and cond_data associated with the per-instance
235  * snapshot associated with the trace_array.
236  *
237  * The cond_snapshot.update() implementation can save data to be
238  * associated with the snapshot if it decides to, and returns 'true'
239  * in that case, or it returns 'false' if the conditional snapshot
240  * shouldn't be taken.
241  *
242  * The cond_snapshot instance is created and associated with the
243  * user-defined cond_data by tracing_cond_snapshot_enable().
244  * Likewise, the cond_snapshot instance is destroyed and is no longer
245  * associated with the trace instance by
246  * tracing_cond_snapshot_disable().
247  *
248  * The method below is required.
249  *
250  * @update: When a conditional snapshot is invoked, the update()
251  *	callback function is invoked with the tr->max_lock held.  The
252  *	update() implementation signals whether or not to actually
253  *	take the snapshot, by returning 'true' if so, 'false' if no
254  *	snapshot should be taken.  Because the max_lock is held for
255  *	the duration of update(), the implementation is safe to
256  *	directly retrieved and save any implementation data it needs
257  *	to in association with the snapshot.
258  */
259 struct cond_snapshot {
260 	void				*cond_data;
261 	cond_update_fn_t		update;
262 };
263 
264 /*
265  * The trace array - an array of per-CPU trace arrays. This is the
266  * highest level data structure that individual tracers deal with.
267  * They have on/off state as well:
268  */
269 struct trace_array {
270 	struct list_head	list;
271 	char			*name;
272 	struct array_buffer	array_buffer;
273 #ifdef CONFIG_TRACER_MAX_TRACE
274 	/*
275 	 * The max_buffer is used to snapshot the trace when a maximum
276 	 * latency is reached, or when the user initiates a snapshot.
277 	 * Some tracers will use this to store a maximum trace while
278 	 * it continues examining live traces.
279 	 *
280 	 * The buffers for the max_buffer are set up the same as the array_buffer
281 	 * When a snapshot is taken, the buffer of the max_buffer is swapped
282 	 * with the buffer of the array_buffer and the buffers are reset for
283 	 * the array_buffer so the tracing can continue.
284 	 */
285 	struct array_buffer	max_buffer;
286 	bool			allocated_snapshot;
287 #endif
288 #if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)
289 	unsigned long		max_latency;
290 #ifdef CONFIG_FSNOTIFY
291 	struct dentry		*d_max_latency;
292 	struct work_struct	fsnotify_work;
293 	struct irq_work		fsnotify_irqwork;
294 #endif
295 #endif
296 	struct trace_pid_list	__rcu *filtered_pids;
297 	struct trace_pid_list	__rcu *filtered_no_pids;
298 	/*
299 	 * max_lock is used to protect the swapping of buffers
300 	 * when taking a max snapshot. The buffers themselves are
301 	 * protected by per_cpu spinlocks. But the action of the swap
302 	 * needs its own lock.
303 	 *
304 	 * This is defined as a arch_spinlock_t in order to help
305 	 * with performance when lockdep debugging is enabled.
306 	 *
307 	 * It is also used in other places outside the update_max_tr
308 	 * so it needs to be defined outside of the
309 	 * CONFIG_TRACER_MAX_TRACE.
310 	 */
311 	arch_spinlock_t		max_lock;
312 	int			buffer_disabled;
313 #ifdef CONFIG_FTRACE_SYSCALLS
314 	int			sys_refcount_enter;
315 	int			sys_refcount_exit;
316 	struct trace_event_file __rcu *enter_syscall_files[NR_syscalls];
317 	struct trace_event_file __rcu *exit_syscall_files[NR_syscalls];
318 #endif
319 	int			stop_count;
320 	int			clock_id;
321 	int			nr_topts;
322 	bool			clear_trace;
323 	int			buffer_percent;
324 	unsigned int		n_err_log_entries;
325 	struct tracer		*current_trace;
326 	unsigned int		trace_flags;
327 	unsigned char		trace_flags_index[TRACE_FLAGS_MAX_SIZE];
328 	unsigned int		flags;
329 	raw_spinlock_t		start_lock;
330 	struct list_head	err_log;
331 	struct dentry		*dir;
332 	struct dentry		*options;
333 	struct dentry		*percpu_dir;
334 	struct dentry		*event_dir;
335 	struct trace_options	*topts;
336 	struct list_head	systems;
337 	struct list_head	events;
338 	struct trace_event_file *trace_marker_file;
339 	cpumask_var_t		tracing_cpumask; /* only trace on set CPUs */
340 	int			ref;
341 	int			trace_ref;
342 #ifdef CONFIG_FUNCTION_TRACER
343 	struct ftrace_ops	*ops;
344 	struct trace_pid_list	__rcu *function_pids;
345 	struct trace_pid_list	__rcu *function_no_pids;
346 #ifdef CONFIG_DYNAMIC_FTRACE
347 	/* All of these are protected by the ftrace_lock */
348 	struct list_head	func_probes;
349 	struct list_head	mod_trace;
350 	struct list_head	mod_notrace;
351 #endif
352 	/* function tracing enabled */
353 	int			function_enabled;
354 #endif
355 	int			time_stamp_abs_ref;
356 	struct list_head	hist_vars;
357 #ifdef CONFIG_TRACER_SNAPSHOT
358 	struct cond_snapshot	*cond_snapshot;
359 #endif
360 };
361 
362 enum {
363 	TRACE_ARRAY_FL_GLOBAL	= (1 << 0)
364 };
365 
366 extern struct list_head ftrace_trace_arrays;
367 
368 extern struct mutex trace_types_lock;
369 
370 extern int trace_array_get(struct trace_array *tr);
371 extern int tracing_check_open_get_tr(struct trace_array *tr);
372 extern struct trace_array *trace_array_find(const char *instance);
373 extern struct trace_array *trace_array_find_get(const char *instance);
374 
375 extern int tracing_set_time_stamp_abs(struct trace_array *tr, bool abs);
376 extern int tracing_set_clock(struct trace_array *tr, const char *clockstr);
377 
378 extern bool trace_clock_in_ns(struct trace_array *tr);
379 
380 /*
381  * The global tracer (top) should be the first trace array added,
382  * but we check the flag anyway.
383  */
384 static inline struct trace_array *top_trace_array(void)
385 {
386 	struct trace_array *tr;
387 
388 	if (list_empty(&ftrace_trace_arrays))
389 		return NULL;
390 
391 	tr = list_entry(ftrace_trace_arrays.prev,
392 			typeof(*tr), list);
393 	WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
394 	return tr;
395 }
396 
397 #define FTRACE_CMP_TYPE(var, type) \
398 	__builtin_types_compatible_p(typeof(var), type *)
399 
400 #undef IF_ASSIGN
401 #define IF_ASSIGN(var, entry, etype, id)			\
402 	if (FTRACE_CMP_TYPE(var, etype)) {			\
403 		var = (typeof(var))(entry);			\
404 		WARN_ON(id != 0 && (entry)->type != id);	\
405 		break;						\
406 	}
407 
408 /* Will cause compile errors if type is not found. */
409 extern void __ftrace_bad_type(void);
410 
411 /*
412  * The trace_assign_type is a verifier that the entry type is
413  * the same as the type being assigned. To add new types simply
414  * add a line with the following format:
415  *
416  * IF_ASSIGN(var, ent, type, id);
417  *
418  *  Where "type" is the trace type that includes the trace_entry
419  *  as the "ent" item. And "id" is the trace identifier that is
420  *  used in the trace_type enum.
421  *
422  *  If the type can have more than one id, then use zero.
423  */
424 #define trace_assign_type(var, ent)					\
425 	do {								\
426 		IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);	\
427 		IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);	\
428 		IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);	\
429 		IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
430 		IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);	\
431 		IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT);	\
432 		IF_ASSIGN(var, ent, struct bputs_entry, TRACE_BPUTS);	\
433 		IF_ASSIGN(var, ent, struct hwlat_entry, TRACE_HWLAT);	\
434 		IF_ASSIGN(var, ent, struct raw_data_entry, TRACE_RAW_DATA);\
435 		IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,		\
436 			  TRACE_MMIO_RW);				\
437 		IF_ASSIGN(var, ent, struct trace_mmiotrace_map,		\
438 			  TRACE_MMIO_MAP);				\
439 		IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
440 		IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,	\
441 			  TRACE_GRAPH_ENT);		\
442 		IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,	\
443 			  TRACE_GRAPH_RET);		\
444 		__ftrace_bad_type();					\
445 	} while (0)
446 
447 /*
448  * An option specific to a tracer. This is a boolean value.
449  * The bit is the bit index that sets its value on the
450  * flags value in struct tracer_flags.
451  */
452 struct tracer_opt {
453 	const char	*name; /* Will appear on the trace_options file */
454 	u32		bit; /* Mask assigned in val field in tracer_flags */
455 };
456 
457 /*
458  * The set of specific options for a tracer. Your tracer
459  * have to set the initial value of the flags val.
460  */
461 struct tracer_flags {
462 	u32			val;
463 	struct tracer_opt	*opts;
464 	struct tracer		*trace;
465 };
466 
467 /* Makes more easy to define a tracer opt */
468 #define TRACER_OPT(s, b)	.name = #s, .bit = b
469 
470 
471 struct trace_option_dentry {
472 	struct tracer_opt		*opt;
473 	struct tracer_flags		*flags;
474 	struct trace_array		*tr;
475 	struct dentry			*entry;
476 };
477 
478 /**
479  * struct tracer - a specific tracer and its callbacks to interact with tracefs
480  * @name: the name chosen to select it on the available_tracers file
481  * @init: called when one switches to this tracer (echo name > current_tracer)
482  * @reset: called when one switches to another tracer
483  * @start: called when tracing is unpaused (echo 1 > tracing_on)
484  * @stop: called when tracing is paused (echo 0 > tracing_on)
485  * @update_thresh: called when tracing_thresh is updated
486  * @open: called when the trace file is opened
487  * @pipe_open: called when the trace_pipe file is opened
488  * @close: called when the trace file is released
489  * @pipe_close: called when the trace_pipe file is released
490  * @read: override the default read callback on trace_pipe
491  * @splice_read: override the default splice_read callback on trace_pipe
492  * @selftest: selftest to run on boot (see trace_selftest.c)
493  * @print_headers: override the first lines that describe your columns
494  * @print_line: callback that prints a trace
495  * @set_flag: signals one of your private flags changed (trace_options file)
496  * @flags: your private flags
497  */
498 struct tracer {
499 	const char		*name;
500 	int			(*init)(struct trace_array *tr);
501 	void			(*reset)(struct trace_array *tr);
502 	void			(*start)(struct trace_array *tr);
503 	void			(*stop)(struct trace_array *tr);
504 	int			(*update_thresh)(struct trace_array *tr);
505 	void			(*open)(struct trace_iterator *iter);
506 	void			(*pipe_open)(struct trace_iterator *iter);
507 	void			(*close)(struct trace_iterator *iter);
508 	void			(*pipe_close)(struct trace_iterator *iter);
509 	ssize_t			(*read)(struct trace_iterator *iter,
510 					struct file *filp, char __user *ubuf,
511 					size_t cnt, loff_t *ppos);
512 	ssize_t			(*splice_read)(struct trace_iterator *iter,
513 					       struct file *filp,
514 					       loff_t *ppos,
515 					       struct pipe_inode_info *pipe,
516 					       size_t len,
517 					       unsigned int flags);
518 #ifdef CONFIG_FTRACE_STARTUP_TEST
519 	int			(*selftest)(struct tracer *trace,
520 					    struct trace_array *tr);
521 #endif
522 	void			(*print_header)(struct seq_file *m);
523 	enum print_line_t	(*print_line)(struct trace_iterator *iter);
524 	/* If you handled the flag setting, return 0 */
525 	int			(*set_flag)(struct trace_array *tr,
526 					    u32 old_flags, u32 bit, int set);
527 	/* Return 0 if OK with change, else return non-zero */
528 	int			(*flag_changed)(struct trace_array *tr,
529 						u32 mask, int set);
530 	struct tracer		*next;
531 	struct tracer_flags	*flags;
532 	int			enabled;
533 	bool			print_max;
534 	bool			allow_instances;
535 #ifdef CONFIG_TRACER_MAX_TRACE
536 	bool			use_max_tr;
537 #endif
538 	/* True if tracer cannot be enabled in kernel param */
539 	bool			noboot;
540 };
541 
542 static inline struct ring_buffer_iter *
543 trace_buffer_iter(struct trace_iterator *iter, int cpu)
544 {
545 	return iter->buffer_iter ? iter->buffer_iter[cpu] : NULL;
546 }
547 
548 int tracer_init(struct tracer *t, struct trace_array *tr);
549 int tracing_is_enabled(void);
550 void tracing_reset_online_cpus(struct array_buffer *buf);
551 void tracing_reset_current(int cpu);
552 void tracing_reset_all_online_cpus(void);
553 int tracing_open_generic(struct inode *inode, struct file *filp);
554 int tracing_open_generic_tr(struct inode *inode, struct file *filp);
555 bool tracing_is_disabled(void);
556 bool tracer_tracing_is_on(struct trace_array *tr);
557 void tracer_tracing_on(struct trace_array *tr);
558 void tracer_tracing_off(struct trace_array *tr);
559 struct dentry *trace_create_file(const char *name,
560 				 umode_t mode,
561 				 struct dentry *parent,
562 				 void *data,
563 				 const struct file_operations *fops);
564 
565 int tracing_init_dentry(void);
566 
567 struct ring_buffer_event;
568 
569 struct ring_buffer_event *
570 trace_buffer_lock_reserve(struct trace_buffer *buffer,
571 			  int type,
572 			  unsigned long len,
573 			  unsigned int trace_ctx);
574 
575 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
576 						struct trace_array_cpu *data);
577 
578 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
579 					  int *ent_cpu, u64 *ent_ts);
580 
581 void trace_buffer_unlock_commit_nostack(struct trace_buffer *buffer,
582 					struct ring_buffer_event *event);
583 
584 const char *trace_event_format(struct trace_iterator *iter, const char *fmt);
585 
586 int trace_empty(struct trace_iterator *iter);
587 
588 void *trace_find_next_entry_inc(struct trace_iterator *iter);
589 
590 void trace_init_global_iter(struct trace_iterator *iter);
591 
592 void tracing_iter_reset(struct trace_iterator *iter, int cpu);
593 
594 unsigned long trace_total_entries_cpu(struct trace_array *tr, int cpu);
595 unsigned long trace_total_entries(struct trace_array *tr);
596 
597 void trace_function(struct trace_array *tr,
598 		    unsigned long ip,
599 		    unsigned long parent_ip,
600 		    unsigned int trace_ctx);
601 void trace_graph_function(struct trace_array *tr,
602 		    unsigned long ip,
603 		    unsigned long parent_ip,
604 		    unsigned int trace_ctx);
605 void trace_latency_header(struct seq_file *m);
606 void trace_default_header(struct seq_file *m);
607 void print_trace_header(struct seq_file *m, struct trace_iterator *iter);
608 
609 void trace_graph_return(struct ftrace_graph_ret *trace);
610 int trace_graph_entry(struct ftrace_graph_ent *trace);
611 void set_graph_array(struct trace_array *tr);
612 
613 void tracing_start_cmdline_record(void);
614 void tracing_stop_cmdline_record(void);
615 void tracing_start_tgid_record(void);
616 void tracing_stop_tgid_record(void);
617 
618 int register_tracer(struct tracer *type);
619 int is_tracing_stopped(void);
620 
621 loff_t tracing_lseek(struct file *file, loff_t offset, int whence);
622 
623 extern cpumask_var_t __read_mostly tracing_buffer_mask;
624 
625 #define for_each_tracing_cpu(cpu)	\
626 	for_each_cpu(cpu, tracing_buffer_mask)
627 
628 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
629 
630 extern unsigned long tracing_thresh;
631 
632 /* PID filtering */
633 
634 extern int pid_max;
635 
636 bool trace_find_filtered_pid(struct trace_pid_list *filtered_pids,
637 			     pid_t search_pid);
638 bool trace_ignore_this_task(struct trace_pid_list *filtered_pids,
639 			    struct trace_pid_list *filtered_no_pids,
640 			    struct task_struct *task);
641 void trace_filter_add_remove_task(struct trace_pid_list *pid_list,
642 				  struct task_struct *self,
643 				  struct task_struct *task);
644 void *trace_pid_next(struct trace_pid_list *pid_list, void *v, loff_t *pos);
645 void *trace_pid_start(struct trace_pid_list *pid_list, loff_t *pos);
646 int trace_pid_show(struct seq_file *m, void *v);
647 void trace_free_pid_list(struct trace_pid_list *pid_list);
648 int trace_pid_write(struct trace_pid_list *filtered_pids,
649 		    struct trace_pid_list **new_pid_list,
650 		    const char __user *ubuf, size_t cnt);
651 
652 #ifdef CONFIG_TRACER_MAX_TRACE
653 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu,
654 		   void *cond_data);
655 void update_max_tr_single(struct trace_array *tr,
656 			  struct task_struct *tsk, int cpu);
657 #endif /* CONFIG_TRACER_MAX_TRACE */
658 
659 #if (defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)) && \
660 	defined(CONFIG_FSNOTIFY)
661 
662 void latency_fsnotify(struct trace_array *tr);
663 
664 #else
665 
666 static inline void latency_fsnotify(struct trace_array *tr) { }
667 
668 #endif
669 
670 #ifdef CONFIG_STACKTRACE
671 void __trace_stack(struct trace_array *tr, unsigned int trace_ctx, int skip);
672 #else
673 static inline void __trace_stack(struct trace_array *tr, unsigned int trace_ctx,
674 				 int skip)
675 {
676 }
677 #endif /* CONFIG_STACKTRACE */
678 
679 extern u64 ftrace_now(int cpu);
680 
681 extern void trace_find_cmdline(int pid, char comm[]);
682 extern int trace_find_tgid(int pid);
683 extern void trace_event_follow_fork(struct trace_array *tr, bool enable);
684 
685 #ifdef CONFIG_DYNAMIC_FTRACE
686 extern unsigned long ftrace_update_tot_cnt;
687 extern unsigned long ftrace_number_of_pages;
688 extern unsigned long ftrace_number_of_groups;
689 void ftrace_init_trace_array(struct trace_array *tr);
690 #else
691 static inline void ftrace_init_trace_array(struct trace_array *tr) { }
692 #endif
693 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
694 extern int DYN_FTRACE_TEST_NAME(void);
695 #define DYN_FTRACE_TEST_NAME2 trace_selftest_dynamic_test_func2
696 extern int DYN_FTRACE_TEST_NAME2(void);
697 
698 extern bool ring_buffer_expanded;
699 extern bool tracing_selftest_disabled;
700 
701 #ifdef CONFIG_FTRACE_STARTUP_TEST
702 extern void __init disable_tracing_selftest(const char *reason);
703 
704 extern int trace_selftest_startup_function(struct tracer *trace,
705 					   struct trace_array *tr);
706 extern int trace_selftest_startup_function_graph(struct tracer *trace,
707 						 struct trace_array *tr);
708 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
709 					  struct trace_array *tr);
710 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
711 					     struct trace_array *tr);
712 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
713 						 struct trace_array *tr);
714 extern int trace_selftest_startup_wakeup(struct tracer *trace,
715 					 struct trace_array *tr);
716 extern int trace_selftest_startup_nop(struct tracer *trace,
717 					 struct trace_array *tr);
718 extern int trace_selftest_startup_branch(struct tracer *trace,
719 					 struct trace_array *tr);
720 /*
721  * Tracer data references selftest functions that only occur
722  * on boot up. These can be __init functions. Thus, when selftests
723  * are enabled, then the tracers need to reference __init functions.
724  */
725 #define __tracer_data		__refdata
726 #else
727 static inline void __init disable_tracing_selftest(const char *reason)
728 {
729 }
730 /* Tracers are seldom changed. Optimize when selftests are disabled. */
731 #define __tracer_data		__read_mostly
732 #endif /* CONFIG_FTRACE_STARTUP_TEST */
733 
734 extern void *head_page(struct trace_array_cpu *data);
735 extern unsigned long long ns2usecs(u64 nsec);
736 extern int
737 trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
738 extern int
739 trace_vprintk(unsigned long ip, const char *fmt, va_list args);
740 extern int
741 trace_array_vprintk(struct trace_array *tr,
742 		    unsigned long ip, const char *fmt, va_list args);
743 int trace_array_printk_buf(struct trace_buffer *buffer,
744 			   unsigned long ip, const char *fmt, ...);
745 void trace_printk_seq(struct trace_seq *s);
746 enum print_line_t print_trace_line(struct trace_iterator *iter);
747 
748 extern char trace_find_mark(unsigned long long duration);
749 
750 struct ftrace_hash;
751 
752 struct ftrace_mod_load {
753 	struct list_head	list;
754 	char			*func;
755 	char			*module;
756 	int			 enable;
757 };
758 
759 enum {
760 	FTRACE_HASH_FL_MOD	= (1 << 0),
761 };
762 
763 struct ftrace_hash {
764 	unsigned long		size_bits;
765 	struct hlist_head	*buckets;
766 	unsigned long		count;
767 	unsigned long		flags;
768 	struct rcu_head		rcu;
769 };
770 
771 struct ftrace_func_entry *
772 ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip);
773 
774 static __always_inline bool ftrace_hash_empty(struct ftrace_hash *hash)
775 {
776 	return !hash || !(hash->count || (hash->flags & FTRACE_HASH_FL_MOD));
777 }
778 
779 /* Standard output formatting function used for function return traces */
780 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
781 
782 /* Flag options */
783 #define TRACE_GRAPH_PRINT_OVERRUN       0x1
784 #define TRACE_GRAPH_PRINT_CPU           0x2
785 #define TRACE_GRAPH_PRINT_OVERHEAD      0x4
786 #define TRACE_GRAPH_PRINT_PROC          0x8
787 #define TRACE_GRAPH_PRINT_DURATION      0x10
788 #define TRACE_GRAPH_PRINT_ABS_TIME      0x20
789 #define TRACE_GRAPH_PRINT_REL_TIME      0x40
790 #define TRACE_GRAPH_PRINT_IRQS          0x80
791 #define TRACE_GRAPH_PRINT_TAIL          0x100
792 #define TRACE_GRAPH_SLEEP_TIME          0x200
793 #define TRACE_GRAPH_GRAPH_TIME          0x400
794 #define TRACE_GRAPH_PRINT_FILL_SHIFT	28
795 #define TRACE_GRAPH_PRINT_FILL_MASK	(0x3 << TRACE_GRAPH_PRINT_FILL_SHIFT)
796 
797 extern void ftrace_graph_sleep_time_control(bool enable);
798 
799 #ifdef CONFIG_FUNCTION_PROFILER
800 extern void ftrace_graph_graph_time_control(bool enable);
801 #else
802 static inline void ftrace_graph_graph_time_control(bool enable) { }
803 #endif
804 
805 extern enum print_line_t
806 print_graph_function_flags(struct trace_iterator *iter, u32 flags);
807 extern void print_graph_headers_flags(struct seq_file *s, u32 flags);
808 extern void
809 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
810 extern void graph_trace_open(struct trace_iterator *iter);
811 extern void graph_trace_close(struct trace_iterator *iter);
812 extern int __trace_graph_entry(struct trace_array *tr,
813 			       struct ftrace_graph_ent *trace,
814 			       unsigned int trace_ctx);
815 extern void __trace_graph_return(struct trace_array *tr,
816 				 struct ftrace_graph_ret *trace,
817 				 unsigned int trace_ctx);
818 
819 #ifdef CONFIG_DYNAMIC_FTRACE
820 extern struct ftrace_hash __rcu *ftrace_graph_hash;
821 extern struct ftrace_hash __rcu *ftrace_graph_notrace_hash;
822 
823 static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace)
824 {
825 	unsigned long addr = trace->func;
826 	int ret = 0;
827 	struct ftrace_hash *hash;
828 
829 	preempt_disable_notrace();
830 
831 	/*
832 	 * Have to open code "rcu_dereference_sched()" because the
833 	 * function graph tracer can be called when RCU is not
834 	 * "watching".
835 	 * Protected with schedule_on_each_cpu(ftrace_sync)
836 	 */
837 	hash = rcu_dereference_protected(ftrace_graph_hash, !preemptible());
838 
839 	if (ftrace_hash_empty(hash)) {
840 		ret = 1;
841 		goto out;
842 	}
843 
844 	if (ftrace_lookup_ip(hash, addr)) {
845 
846 		/*
847 		 * This needs to be cleared on the return functions
848 		 * when the depth is zero.
849 		 */
850 		trace_recursion_set(TRACE_GRAPH_BIT);
851 		trace_recursion_set_depth(trace->depth);
852 
853 		/*
854 		 * If no irqs are to be traced, but a set_graph_function
855 		 * is set, and called by an interrupt handler, we still
856 		 * want to trace it.
857 		 */
858 		if (in_irq())
859 			trace_recursion_set(TRACE_IRQ_BIT);
860 		else
861 			trace_recursion_clear(TRACE_IRQ_BIT);
862 		ret = 1;
863 	}
864 
865 out:
866 	preempt_enable_notrace();
867 	return ret;
868 }
869 
870 static inline void ftrace_graph_addr_finish(struct ftrace_graph_ret *trace)
871 {
872 	if (trace_recursion_test(TRACE_GRAPH_BIT) &&
873 	    trace->depth == trace_recursion_depth())
874 		trace_recursion_clear(TRACE_GRAPH_BIT);
875 }
876 
877 static inline int ftrace_graph_notrace_addr(unsigned long addr)
878 {
879 	int ret = 0;
880 	struct ftrace_hash *notrace_hash;
881 
882 	preempt_disable_notrace();
883 
884 	/*
885 	 * Have to open code "rcu_dereference_sched()" because the
886 	 * function graph tracer can be called when RCU is not
887 	 * "watching".
888 	 * Protected with schedule_on_each_cpu(ftrace_sync)
889 	 */
890 	notrace_hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
891 						 !preemptible());
892 
893 	if (ftrace_lookup_ip(notrace_hash, addr))
894 		ret = 1;
895 
896 	preempt_enable_notrace();
897 	return ret;
898 }
899 #else
900 static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace)
901 {
902 	return 1;
903 }
904 
905 static inline int ftrace_graph_notrace_addr(unsigned long addr)
906 {
907 	return 0;
908 }
909 static inline void ftrace_graph_addr_finish(struct ftrace_graph_ret *trace)
910 { }
911 #endif /* CONFIG_DYNAMIC_FTRACE */
912 
913 extern unsigned int fgraph_max_depth;
914 
915 static inline bool ftrace_graph_ignore_func(struct ftrace_graph_ent *trace)
916 {
917 	/* trace it when it is-nested-in or is a function enabled. */
918 	return !(trace_recursion_test(TRACE_GRAPH_BIT) ||
919 		 ftrace_graph_addr(trace)) ||
920 		(trace->depth < 0) ||
921 		(fgraph_max_depth && trace->depth >= fgraph_max_depth);
922 }
923 
924 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
925 static inline enum print_line_t
926 print_graph_function_flags(struct trace_iterator *iter, u32 flags)
927 {
928 	return TRACE_TYPE_UNHANDLED;
929 }
930 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
931 
932 extern struct list_head ftrace_pids;
933 
934 #ifdef CONFIG_FUNCTION_TRACER
935 
936 #define FTRACE_PID_IGNORE	-1
937 #define FTRACE_PID_TRACE	-2
938 
939 struct ftrace_func_command {
940 	struct list_head	list;
941 	char			*name;
942 	int			(*func)(struct trace_array *tr,
943 					struct ftrace_hash *hash,
944 					char *func, char *cmd,
945 					char *params, int enable);
946 };
947 extern bool ftrace_filter_param __initdata;
948 static inline int ftrace_trace_task(struct trace_array *tr)
949 {
950 	return this_cpu_read(tr->array_buffer.data->ftrace_ignore_pid) !=
951 		FTRACE_PID_IGNORE;
952 }
953 extern int ftrace_is_dead(void);
954 int ftrace_create_function_files(struct trace_array *tr,
955 				 struct dentry *parent);
956 void ftrace_destroy_function_files(struct trace_array *tr);
957 int ftrace_allocate_ftrace_ops(struct trace_array *tr);
958 void ftrace_free_ftrace_ops(struct trace_array *tr);
959 void ftrace_init_global_array_ops(struct trace_array *tr);
960 void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func);
961 void ftrace_reset_array_ops(struct trace_array *tr);
962 void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer);
963 void ftrace_init_tracefs_toplevel(struct trace_array *tr,
964 				  struct dentry *d_tracer);
965 void ftrace_clear_pids(struct trace_array *tr);
966 int init_function_trace(void);
967 void ftrace_pid_follow_fork(struct trace_array *tr, bool enable);
968 #else
969 static inline int ftrace_trace_task(struct trace_array *tr)
970 {
971 	return 1;
972 }
973 static inline int ftrace_is_dead(void) { return 0; }
974 static inline int
975 ftrace_create_function_files(struct trace_array *tr,
976 			     struct dentry *parent)
977 {
978 	return 0;
979 }
980 static inline int ftrace_allocate_ftrace_ops(struct trace_array *tr)
981 {
982 	return 0;
983 }
984 static inline void ftrace_free_ftrace_ops(struct trace_array *tr) { }
985 static inline void ftrace_destroy_function_files(struct trace_array *tr) { }
986 static inline __init void
987 ftrace_init_global_array_ops(struct trace_array *tr) { }
988 static inline void ftrace_reset_array_ops(struct trace_array *tr) { }
989 static inline void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d) { }
990 static inline void ftrace_init_tracefs_toplevel(struct trace_array *tr, struct dentry *d) { }
991 static inline void ftrace_clear_pids(struct trace_array *tr) { }
992 static inline int init_function_trace(void) { return 0; }
993 static inline void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) { }
994 /* ftace_func_t type is not defined, use macro instead of static inline */
995 #define ftrace_init_array_ops(tr, func) do { } while (0)
996 #endif /* CONFIG_FUNCTION_TRACER */
997 
998 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
999 
1000 struct ftrace_probe_ops {
1001 	void			(*func)(unsigned long ip,
1002 					unsigned long parent_ip,
1003 					struct trace_array *tr,
1004 					struct ftrace_probe_ops *ops,
1005 					void *data);
1006 	int			(*init)(struct ftrace_probe_ops *ops,
1007 					struct trace_array *tr,
1008 					unsigned long ip, void *init_data,
1009 					void **data);
1010 	void			(*free)(struct ftrace_probe_ops *ops,
1011 					struct trace_array *tr,
1012 					unsigned long ip, void *data);
1013 	int			(*print)(struct seq_file *m,
1014 					 unsigned long ip,
1015 					 struct ftrace_probe_ops *ops,
1016 					 void *data);
1017 };
1018 
1019 struct ftrace_func_mapper;
1020 typedef int (*ftrace_mapper_func)(void *data);
1021 
1022 struct ftrace_func_mapper *allocate_ftrace_func_mapper(void);
1023 void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
1024 					   unsigned long ip);
1025 int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
1026 			       unsigned long ip, void *data);
1027 void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
1028 				   unsigned long ip);
1029 void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
1030 			     ftrace_mapper_func free_func);
1031 
1032 extern int
1033 register_ftrace_function_probe(char *glob, struct trace_array *tr,
1034 			       struct ftrace_probe_ops *ops, void *data);
1035 extern int
1036 unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
1037 				      struct ftrace_probe_ops *ops);
1038 extern void clear_ftrace_function_probes(struct trace_array *tr);
1039 
1040 int register_ftrace_command(struct ftrace_func_command *cmd);
1041 int unregister_ftrace_command(struct ftrace_func_command *cmd);
1042 
1043 void ftrace_create_filter_files(struct ftrace_ops *ops,
1044 				struct dentry *parent);
1045 void ftrace_destroy_filter_files(struct ftrace_ops *ops);
1046 
1047 extern int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
1048 			     int len, int reset);
1049 extern int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
1050 			      int len, int reset);
1051 #else
1052 struct ftrace_func_command;
1053 
1054 static inline __init int register_ftrace_command(struct ftrace_func_command *cmd)
1055 {
1056 	return -EINVAL;
1057 }
1058 static inline __init int unregister_ftrace_command(char *cmd_name)
1059 {
1060 	return -EINVAL;
1061 }
1062 static inline void clear_ftrace_function_probes(struct trace_array *tr)
1063 {
1064 }
1065 
1066 /*
1067  * The ops parameter passed in is usually undefined.
1068  * This must be a macro.
1069  */
1070 #define ftrace_create_filter_files(ops, parent) do { } while (0)
1071 #define ftrace_destroy_filter_files(ops) do { } while (0)
1072 #endif /* CONFIG_FUNCTION_TRACER && CONFIG_DYNAMIC_FTRACE */
1073 
1074 bool ftrace_event_is_function(struct trace_event_call *call);
1075 
1076 /*
1077  * struct trace_parser - servers for reading the user input separated by spaces
1078  * @cont: set if the input is not complete - no final space char was found
1079  * @buffer: holds the parsed user input
1080  * @idx: user input length
1081  * @size: buffer size
1082  */
1083 struct trace_parser {
1084 	bool		cont;
1085 	char		*buffer;
1086 	unsigned	idx;
1087 	unsigned	size;
1088 };
1089 
1090 static inline bool trace_parser_loaded(struct trace_parser *parser)
1091 {
1092 	return (parser->idx != 0);
1093 }
1094 
1095 static inline bool trace_parser_cont(struct trace_parser *parser)
1096 {
1097 	return parser->cont;
1098 }
1099 
1100 static inline void trace_parser_clear(struct trace_parser *parser)
1101 {
1102 	parser->cont = false;
1103 	parser->idx = 0;
1104 }
1105 
1106 extern int trace_parser_get_init(struct trace_parser *parser, int size);
1107 extern void trace_parser_put(struct trace_parser *parser);
1108 extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
1109 	size_t cnt, loff_t *ppos);
1110 
1111 /*
1112  * Only create function graph options if function graph is configured.
1113  */
1114 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1115 # define FGRAPH_FLAGS						\
1116 		C(DISPLAY_GRAPH,	"display-graph"),
1117 #else
1118 # define FGRAPH_FLAGS
1119 #endif
1120 
1121 #ifdef CONFIG_BRANCH_TRACER
1122 # define BRANCH_FLAGS					\
1123 		C(BRANCH,		"branch"),
1124 #else
1125 # define BRANCH_FLAGS
1126 #endif
1127 
1128 #ifdef CONFIG_FUNCTION_TRACER
1129 # define FUNCTION_FLAGS						\
1130 		C(FUNCTION,		"function-trace"),	\
1131 		C(FUNC_FORK,		"function-fork"),
1132 # define FUNCTION_DEFAULT_FLAGS		TRACE_ITER_FUNCTION
1133 #else
1134 # define FUNCTION_FLAGS
1135 # define FUNCTION_DEFAULT_FLAGS		0UL
1136 # define TRACE_ITER_FUNC_FORK		0UL
1137 #endif
1138 
1139 #ifdef CONFIG_STACKTRACE
1140 # define STACK_FLAGS				\
1141 		C(STACKTRACE,		"stacktrace"),
1142 #else
1143 # define STACK_FLAGS
1144 #endif
1145 
1146 /*
1147  * trace_iterator_flags is an enumeration that defines bit
1148  * positions into trace_flags that controls the output.
1149  *
1150  * NOTE: These bits must match the trace_options array in
1151  *       trace.c (this macro guarantees it).
1152  */
1153 #define TRACE_FLAGS						\
1154 		C(PRINT_PARENT,		"print-parent"),	\
1155 		C(SYM_OFFSET,		"sym-offset"),		\
1156 		C(SYM_ADDR,		"sym-addr"),		\
1157 		C(VERBOSE,		"verbose"),		\
1158 		C(RAW,			"raw"),			\
1159 		C(HEX,			"hex"),			\
1160 		C(BIN,			"bin"),			\
1161 		C(BLOCK,		"block"),		\
1162 		C(PRINTK,		"trace_printk"),	\
1163 		C(ANNOTATE,		"annotate"),		\
1164 		C(USERSTACKTRACE,	"userstacktrace"),	\
1165 		C(SYM_USEROBJ,		"sym-userobj"),		\
1166 		C(PRINTK_MSGONLY,	"printk-msg-only"),	\
1167 		C(CONTEXT_INFO,		"context-info"),   /* Print pid/cpu/time */ \
1168 		C(LATENCY_FMT,		"latency-format"),	\
1169 		C(RECORD_CMD,		"record-cmd"),		\
1170 		C(RECORD_TGID,		"record-tgid"),		\
1171 		C(OVERWRITE,		"overwrite"),		\
1172 		C(STOP_ON_FREE,		"disable_on_free"),	\
1173 		C(IRQ_INFO,		"irq-info"),		\
1174 		C(MARKERS,		"markers"),		\
1175 		C(EVENT_FORK,		"event-fork"),		\
1176 		C(PAUSE_ON_TRACE,	"pause-on-trace"),	\
1177 		C(HASH_PTR,		"hash-ptr"),	/* Print hashed pointer */ \
1178 		FUNCTION_FLAGS					\
1179 		FGRAPH_FLAGS					\
1180 		STACK_FLAGS					\
1181 		BRANCH_FLAGS
1182 
1183 /*
1184  * By defining C, we can make TRACE_FLAGS a list of bit names
1185  * that will define the bits for the flag masks.
1186  */
1187 #undef C
1188 #define C(a, b) TRACE_ITER_##a##_BIT
1189 
1190 enum trace_iterator_bits {
1191 	TRACE_FLAGS
1192 	/* Make sure we don't go more than we have bits for */
1193 	TRACE_ITER_LAST_BIT
1194 };
1195 
1196 /*
1197  * By redefining C, we can make TRACE_FLAGS a list of masks that
1198  * use the bits as defined above.
1199  */
1200 #undef C
1201 #define C(a, b) TRACE_ITER_##a = (1 << TRACE_ITER_##a##_BIT)
1202 
1203 enum trace_iterator_flags { TRACE_FLAGS };
1204 
1205 /*
1206  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
1207  * control the output of kernel symbols.
1208  */
1209 #define TRACE_ITER_SYM_MASK \
1210 	(TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
1211 
1212 extern struct tracer nop_trace;
1213 
1214 #ifdef CONFIG_BRANCH_TRACER
1215 extern int enable_branch_tracing(struct trace_array *tr);
1216 extern void disable_branch_tracing(void);
1217 static inline int trace_branch_enable(struct trace_array *tr)
1218 {
1219 	if (tr->trace_flags & TRACE_ITER_BRANCH)
1220 		return enable_branch_tracing(tr);
1221 	return 0;
1222 }
1223 static inline void trace_branch_disable(void)
1224 {
1225 	/* due to races, always disable */
1226 	disable_branch_tracing();
1227 }
1228 #else
1229 static inline int trace_branch_enable(struct trace_array *tr)
1230 {
1231 	return 0;
1232 }
1233 static inline void trace_branch_disable(void)
1234 {
1235 }
1236 #endif /* CONFIG_BRANCH_TRACER */
1237 
1238 /* set ring buffers to default size if not already done so */
1239 int tracing_update_buffers(void);
1240 
1241 struct ftrace_event_field {
1242 	struct list_head	link;
1243 	const char		*name;
1244 	const char		*type;
1245 	int			filter_type;
1246 	int			offset;
1247 	int			size;
1248 	int			is_signed;
1249 };
1250 
1251 struct prog_entry;
1252 
1253 struct event_filter {
1254 	struct prog_entry __rcu	*prog;
1255 	char			*filter_string;
1256 };
1257 
1258 struct event_subsystem {
1259 	struct list_head	list;
1260 	const char		*name;
1261 	struct event_filter	*filter;
1262 	int			ref_count;
1263 };
1264 
1265 struct trace_subsystem_dir {
1266 	struct list_head		list;
1267 	struct event_subsystem		*subsystem;
1268 	struct trace_array		*tr;
1269 	struct dentry			*entry;
1270 	int				ref_count;
1271 	int				nr_events;
1272 };
1273 
1274 extern int call_filter_check_discard(struct trace_event_call *call, void *rec,
1275 				     struct trace_buffer *buffer,
1276 				     struct ring_buffer_event *event);
1277 
1278 void trace_buffer_unlock_commit_regs(struct trace_array *tr,
1279 				     struct trace_buffer *buffer,
1280 				     struct ring_buffer_event *event,
1281 				     unsigned int trcace_ctx,
1282 				     struct pt_regs *regs);
1283 
1284 static inline void trace_buffer_unlock_commit(struct trace_array *tr,
1285 					      struct trace_buffer *buffer,
1286 					      struct ring_buffer_event *event,
1287 					      unsigned int trace_ctx)
1288 {
1289 	trace_buffer_unlock_commit_regs(tr, buffer, event, trace_ctx, NULL);
1290 }
1291 
1292 DECLARE_PER_CPU(struct ring_buffer_event *, trace_buffered_event);
1293 DECLARE_PER_CPU(int, trace_buffered_event_cnt);
1294 void trace_buffered_event_disable(void);
1295 void trace_buffered_event_enable(void);
1296 
1297 static inline void
1298 __trace_event_discard_commit(struct trace_buffer *buffer,
1299 			     struct ring_buffer_event *event)
1300 {
1301 	if (this_cpu_read(trace_buffered_event) == event) {
1302 		/* Simply release the temp buffer */
1303 		this_cpu_dec(trace_buffered_event_cnt);
1304 		return;
1305 	}
1306 	ring_buffer_discard_commit(buffer, event);
1307 }
1308 
1309 /*
1310  * Helper function for event_trigger_unlock_commit{_regs}().
1311  * If there are event triggers attached to this event that requires
1312  * filtering against its fields, then they will be called as the
1313  * entry already holds the field information of the current event.
1314  *
1315  * It also checks if the event should be discarded or not.
1316  * It is to be discarded if the event is soft disabled and the
1317  * event was only recorded to process triggers, or if the event
1318  * filter is active and this event did not match the filters.
1319  *
1320  * Returns true if the event is discarded, false otherwise.
1321  */
1322 static inline bool
1323 __event_trigger_test_discard(struct trace_event_file *file,
1324 			     struct trace_buffer *buffer,
1325 			     struct ring_buffer_event *event,
1326 			     void *entry,
1327 			     enum event_trigger_type *tt)
1328 {
1329 	unsigned long eflags = file->flags;
1330 
1331 	if (eflags & EVENT_FILE_FL_TRIGGER_COND)
1332 		*tt = event_triggers_call(file, entry, event);
1333 
1334 	if (test_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags) ||
1335 	    (unlikely(file->flags & EVENT_FILE_FL_FILTERED) &&
1336 	     !filter_match_preds(file->filter, entry))) {
1337 		__trace_event_discard_commit(buffer, event);
1338 		return true;
1339 	}
1340 
1341 	return false;
1342 }
1343 
1344 /**
1345  * event_trigger_unlock_commit - handle triggers and finish event commit
1346  * @file: The file pointer assoctiated to the event
1347  * @buffer: The ring buffer that the event is being written to
1348  * @event: The event meta data in the ring buffer
1349  * @entry: The event itself
1350  * @trace_ctx: The tracing context flags.
1351  *
1352  * This is a helper function to handle triggers that require data
1353  * from the event itself. It also tests the event against filters and
1354  * if the event is soft disabled and should be discarded.
1355  */
1356 static inline void
1357 event_trigger_unlock_commit(struct trace_event_file *file,
1358 			    struct trace_buffer *buffer,
1359 			    struct ring_buffer_event *event,
1360 			    void *entry, unsigned int trace_ctx)
1361 {
1362 	enum event_trigger_type tt = ETT_NONE;
1363 
1364 	if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1365 		trace_buffer_unlock_commit(file->tr, buffer, event, trace_ctx);
1366 
1367 	if (tt)
1368 		event_triggers_post_call(file, tt);
1369 }
1370 
1371 /**
1372  * event_trigger_unlock_commit_regs - handle triggers and finish event commit
1373  * @file: The file pointer assoctiated to the event
1374  * @buffer: The ring buffer that the event is being written to
1375  * @event: The event meta data in the ring buffer
1376  * @entry: The event itself
1377  * @trace_ctx: The tracing context flags.
1378  *
1379  * This is a helper function to handle triggers that require data
1380  * from the event itself. It also tests the event against filters and
1381  * if the event is soft disabled and should be discarded.
1382  *
1383  * Same as event_trigger_unlock_commit() but calls
1384  * trace_buffer_unlock_commit_regs() instead of trace_buffer_unlock_commit().
1385  */
1386 static inline void
1387 event_trigger_unlock_commit_regs(struct trace_event_file *file,
1388 				 struct trace_buffer *buffer,
1389 				 struct ring_buffer_event *event,
1390 				 void *entry, unsigned int trace_ctx,
1391 				 struct pt_regs *regs)
1392 {
1393 	enum event_trigger_type tt = ETT_NONE;
1394 
1395 	if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1396 		trace_buffer_unlock_commit_regs(file->tr, buffer, event,
1397 						trace_ctx, regs);
1398 
1399 	if (tt)
1400 		event_triggers_post_call(file, tt);
1401 }
1402 
1403 #define FILTER_PRED_INVALID	((unsigned short)-1)
1404 #define FILTER_PRED_IS_RIGHT	(1 << 15)
1405 #define FILTER_PRED_FOLD	(1 << 15)
1406 
1407 /*
1408  * The max preds is the size of unsigned short with
1409  * two flags at the MSBs. One bit is used for both the IS_RIGHT
1410  * and FOLD flags. The other is reserved.
1411  *
1412  * 2^14 preds is way more than enough.
1413  */
1414 #define MAX_FILTER_PRED		16384
1415 
1416 struct filter_pred;
1417 struct regex;
1418 
1419 typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event);
1420 
1421 typedef int (*regex_match_func)(char *str, struct regex *r, int len);
1422 
1423 enum regex_type {
1424 	MATCH_FULL = 0,
1425 	MATCH_FRONT_ONLY,
1426 	MATCH_MIDDLE_ONLY,
1427 	MATCH_END_ONLY,
1428 	MATCH_GLOB,
1429 	MATCH_INDEX,
1430 };
1431 
1432 struct regex {
1433 	char			pattern[MAX_FILTER_STR_VAL];
1434 	int			len;
1435 	int			field_len;
1436 	regex_match_func	match;
1437 };
1438 
1439 struct filter_pred {
1440 	filter_pred_fn_t 	fn;
1441 	u64 			val;
1442 	struct regex		regex;
1443 	unsigned short		*ops;
1444 	struct ftrace_event_field *field;
1445 	int 			offset;
1446 	int			not;
1447 	int 			op;
1448 };
1449 
1450 static inline bool is_string_field(struct ftrace_event_field *field)
1451 {
1452 	return field->filter_type == FILTER_DYN_STRING ||
1453 	       field->filter_type == FILTER_STATIC_STRING ||
1454 	       field->filter_type == FILTER_PTR_STRING ||
1455 	       field->filter_type == FILTER_COMM;
1456 }
1457 
1458 static inline bool is_function_field(struct ftrace_event_field *field)
1459 {
1460 	return field->filter_type == FILTER_TRACE_FN;
1461 }
1462 
1463 extern enum regex_type
1464 filter_parse_regex(char *buff, int len, char **search, int *not);
1465 extern void print_event_filter(struct trace_event_file *file,
1466 			       struct trace_seq *s);
1467 extern int apply_event_filter(struct trace_event_file *file,
1468 			      char *filter_string);
1469 extern int apply_subsystem_event_filter(struct trace_subsystem_dir *dir,
1470 					char *filter_string);
1471 extern void print_subsystem_event_filter(struct event_subsystem *system,
1472 					 struct trace_seq *s);
1473 extern int filter_assign_type(const char *type);
1474 extern int create_event_filter(struct trace_array *tr,
1475 			       struct trace_event_call *call,
1476 			       char *filter_str, bool set_str,
1477 			       struct event_filter **filterp);
1478 extern void free_event_filter(struct event_filter *filter);
1479 
1480 struct ftrace_event_field *
1481 trace_find_event_field(struct trace_event_call *call, char *name);
1482 
1483 extern void trace_event_enable_cmd_record(bool enable);
1484 extern void trace_event_enable_tgid_record(bool enable);
1485 
1486 extern int event_trace_init(void);
1487 extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
1488 extern int event_trace_del_tracer(struct trace_array *tr);
1489 extern void __trace_early_add_events(struct trace_array *tr);
1490 
1491 extern struct trace_event_file *__find_event_file(struct trace_array *tr,
1492 						  const char *system,
1493 						  const char *event);
1494 extern struct trace_event_file *find_event_file(struct trace_array *tr,
1495 						const char *system,
1496 						const char *event);
1497 
1498 static inline void *event_file_data(struct file *filp)
1499 {
1500 	return READ_ONCE(file_inode(filp)->i_private);
1501 }
1502 
1503 extern struct mutex event_mutex;
1504 extern struct list_head ftrace_events;
1505 
1506 extern const struct file_operations event_trigger_fops;
1507 extern const struct file_operations event_hist_fops;
1508 extern const struct file_operations event_hist_debug_fops;
1509 extern const struct file_operations event_inject_fops;
1510 
1511 #ifdef CONFIG_HIST_TRIGGERS
1512 extern int register_trigger_hist_cmd(void);
1513 extern int register_trigger_hist_enable_disable_cmds(void);
1514 #else
1515 static inline int register_trigger_hist_cmd(void) { return 0; }
1516 static inline int register_trigger_hist_enable_disable_cmds(void) { return 0; }
1517 #endif
1518 
1519 extern int register_trigger_cmds(void);
1520 extern void clear_event_triggers(struct trace_array *tr);
1521 
1522 struct event_trigger_data {
1523 	unsigned long			count;
1524 	int				ref;
1525 	struct event_trigger_ops	*ops;
1526 	struct event_command		*cmd_ops;
1527 	struct event_filter __rcu	*filter;
1528 	char				*filter_str;
1529 	void				*private_data;
1530 	bool				paused;
1531 	bool				paused_tmp;
1532 	struct list_head		list;
1533 	char				*name;
1534 	struct list_head		named_list;
1535 	struct event_trigger_data	*named_data;
1536 };
1537 
1538 /* Avoid typos */
1539 #define ENABLE_EVENT_STR	"enable_event"
1540 #define DISABLE_EVENT_STR	"disable_event"
1541 #define ENABLE_HIST_STR		"enable_hist"
1542 #define DISABLE_HIST_STR	"disable_hist"
1543 
1544 struct enable_trigger_data {
1545 	struct trace_event_file		*file;
1546 	bool				enable;
1547 	bool				hist;
1548 };
1549 
1550 extern int event_enable_trigger_print(struct seq_file *m,
1551 				      struct event_trigger_ops *ops,
1552 				      struct event_trigger_data *data);
1553 extern void event_enable_trigger_free(struct event_trigger_ops *ops,
1554 				      struct event_trigger_data *data);
1555 extern int event_enable_trigger_func(struct event_command *cmd_ops,
1556 				     struct trace_event_file *file,
1557 				     char *glob, char *cmd, char *param);
1558 extern int event_enable_register_trigger(char *glob,
1559 					 struct event_trigger_ops *ops,
1560 					 struct event_trigger_data *data,
1561 					 struct trace_event_file *file);
1562 extern void event_enable_unregister_trigger(char *glob,
1563 					    struct event_trigger_ops *ops,
1564 					    struct event_trigger_data *test,
1565 					    struct trace_event_file *file);
1566 extern void trigger_data_free(struct event_trigger_data *data);
1567 extern int event_trigger_init(struct event_trigger_ops *ops,
1568 			      struct event_trigger_data *data);
1569 extern int trace_event_trigger_enable_disable(struct trace_event_file *file,
1570 					      int trigger_enable);
1571 extern void update_cond_flag(struct trace_event_file *file);
1572 extern int set_trigger_filter(char *filter_str,
1573 			      struct event_trigger_data *trigger_data,
1574 			      struct trace_event_file *file);
1575 extern struct event_trigger_data *find_named_trigger(const char *name);
1576 extern bool is_named_trigger(struct event_trigger_data *test);
1577 extern int save_named_trigger(const char *name,
1578 			      struct event_trigger_data *data);
1579 extern void del_named_trigger(struct event_trigger_data *data);
1580 extern void pause_named_trigger(struct event_trigger_data *data);
1581 extern void unpause_named_trigger(struct event_trigger_data *data);
1582 extern void set_named_trigger_data(struct event_trigger_data *data,
1583 				   struct event_trigger_data *named_data);
1584 extern struct event_trigger_data *
1585 get_named_trigger_data(struct event_trigger_data *data);
1586 extern int register_event_command(struct event_command *cmd);
1587 extern int unregister_event_command(struct event_command *cmd);
1588 extern int register_trigger_hist_enable_disable_cmds(void);
1589 
1590 /**
1591  * struct event_trigger_ops - callbacks for trace event triggers
1592  *
1593  * The methods in this structure provide per-event trigger hooks for
1594  * various trigger operations.
1595  *
1596  * All the methods below, except for @init() and @free(), must be
1597  * implemented.
1598  *
1599  * @func: The trigger 'probe' function called when the triggering
1600  *	event occurs.  The data passed into this callback is the data
1601  *	that was supplied to the event_command @reg() function that
1602  *	registered the trigger (see struct event_command) along with
1603  *	the trace record, rec.
1604  *
1605  * @init: An optional initialization function called for the trigger
1606  *	when the trigger is registered (via the event_command reg()
1607  *	function).  This can be used to perform per-trigger
1608  *	initialization such as incrementing a per-trigger reference
1609  *	count, for instance.  This is usually implemented by the
1610  *	generic utility function @event_trigger_init() (see
1611  *	trace_event_triggers.c).
1612  *
1613  * @free: An optional de-initialization function called for the
1614  *	trigger when the trigger is unregistered (via the
1615  *	event_command @reg() function).  This can be used to perform
1616  *	per-trigger de-initialization such as decrementing a
1617  *	per-trigger reference count and freeing corresponding trigger
1618  *	data, for instance.  This is usually implemented by the
1619  *	generic utility function @event_trigger_free() (see
1620  *	trace_event_triggers.c).
1621  *
1622  * @print: The callback function invoked to have the trigger print
1623  *	itself.  This is usually implemented by a wrapper function
1624  *	that calls the generic utility function @event_trigger_print()
1625  *	(see trace_event_triggers.c).
1626  */
1627 struct event_trigger_ops {
1628 	void			(*func)(struct event_trigger_data *data,
1629 					void *rec,
1630 					struct ring_buffer_event *rbe);
1631 	int			(*init)(struct event_trigger_ops *ops,
1632 					struct event_trigger_data *data);
1633 	void			(*free)(struct event_trigger_ops *ops,
1634 					struct event_trigger_data *data);
1635 	int			(*print)(struct seq_file *m,
1636 					 struct event_trigger_ops *ops,
1637 					 struct event_trigger_data *data);
1638 };
1639 
1640 /**
1641  * struct event_command - callbacks and data members for event commands
1642  *
1643  * Event commands are invoked by users by writing the command name
1644  * into the 'trigger' file associated with a trace event.  The
1645  * parameters associated with a specific invocation of an event
1646  * command are used to create an event trigger instance, which is
1647  * added to the list of trigger instances associated with that trace
1648  * event.  When the event is hit, the set of triggers associated with
1649  * that event is invoked.
1650  *
1651  * The data members in this structure provide per-event command data
1652  * for various event commands.
1653  *
1654  * All the data members below, except for @post_trigger, must be set
1655  * for each event command.
1656  *
1657  * @name: The unique name that identifies the event command.  This is
1658  *	the name used when setting triggers via trigger files.
1659  *
1660  * @trigger_type: A unique id that identifies the event command
1661  *	'type'.  This value has two purposes, the first to ensure that
1662  *	only one trigger of the same type can be set at a given time
1663  *	for a particular event e.g. it doesn't make sense to have both
1664  *	a traceon and traceoff trigger attached to a single event at
1665  *	the same time, so traceon and traceoff have the same type
1666  *	though they have different names.  The @trigger_type value is
1667  *	also used as a bit value for deferring the actual trigger
1668  *	action until after the current event is finished.  Some
1669  *	commands need to do this if they themselves log to the trace
1670  *	buffer (see the @post_trigger() member below).  @trigger_type
1671  *	values are defined by adding new values to the trigger_type
1672  *	enum in include/linux/trace_events.h.
1673  *
1674  * @flags: See the enum event_command_flags below.
1675  *
1676  * All the methods below, except for @set_filter() and @unreg_all(),
1677  * must be implemented.
1678  *
1679  * @func: The callback function responsible for parsing and
1680  *	registering the trigger written to the 'trigger' file by the
1681  *	user.  It allocates the trigger instance and registers it with
1682  *	the appropriate trace event.  It makes use of the other
1683  *	event_command callback functions to orchestrate this, and is
1684  *	usually implemented by the generic utility function
1685  *	@event_trigger_callback() (see trace_event_triggers.c).
1686  *
1687  * @reg: Adds the trigger to the list of triggers associated with the
1688  *	event, and enables the event trigger itself, after
1689  *	initializing it (via the event_trigger_ops @init() function).
1690  *	This is also where commands can use the @trigger_type value to
1691  *	make the decision as to whether or not multiple instances of
1692  *	the trigger should be allowed.  This is usually implemented by
1693  *	the generic utility function @register_trigger() (see
1694  *	trace_event_triggers.c).
1695  *
1696  * @unreg: Removes the trigger from the list of triggers associated
1697  *	with the event, and disables the event trigger itself, after
1698  *	initializing it (via the event_trigger_ops @free() function).
1699  *	This is usually implemented by the generic utility function
1700  *	@unregister_trigger() (see trace_event_triggers.c).
1701  *
1702  * @unreg_all: An optional function called to remove all the triggers
1703  *	from the list of triggers associated with the event.  Called
1704  *	when a trigger file is opened in truncate mode.
1705  *
1706  * @set_filter: An optional function called to parse and set a filter
1707  *	for the trigger.  If no @set_filter() method is set for the
1708  *	event command, filters set by the user for the command will be
1709  *	ignored.  This is usually implemented by the generic utility
1710  *	function @set_trigger_filter() (see trace_event_triggers.c).
1711  *
1712  * @get_trigger_ops: The callback function invoked to retrieve the
1713  *	event_trigger_ops implementation associated with the command.
1714  */
1715 struct event_command {
1716 	struct list_head	list;
1717 	char			*name;
1718 	enum event_trigger_type	trigger_type;
1719 	int			flags;
1720 	int			(*func)(struct event_command *cmd_ops,
1721 					struct trace_event_file *file,
1722 					char *glob, char *cmd, char *params);
1723 	int			(*reg)(char *glob,
1724 				       struct event_trigger_ops *ops,
1725 				       struct event_trigger_data *data,
1726 				       struct trace_event_file *file);
1727 	void			(*unreg)(char *glob,
1728 					 struct event_trigger_ops *ops,
1729 					 struct event_trigger_data *data,
1730 					 struct trace_event_file *file);
1731 	void			(*unreg_all)(struct trace_event_file *file);
1732 	int			(*set_filter)(char *filter_str,
1733 					      struct event_trigger_data *data,
1734 					      struct trace_event_file *file);
1735 	struct event_trigger_ops *(*get_trigger_ops)(char *cmd, char *param);
1736 };
1737 
1738 /**
1739  * enum event_command_flags - flags for struct event_command
1740  *
1741  * @POST_TRIGGER: A flag that says whether or not this command needs
1742  *	to have its action delayed until after the current event has
1743  *	been closed.  Some triggers need to avoid being invoked while
1744  *	an event is currently in the process of being logged, since
1745  *	the trigger may itself log data into the trace buffer.  Thus
1746  *	we make sure the current event is committed before invoking
1747  *	those triggers.  To do that, the trigger invocation is split
1748  *	in two - the first part checks the filter using the current
1749  *	trace record; if a command has the @post_trigger flag set, it
1750  *	sets a bit for itself in the return value, otherwise it
1751  *	directly invokes the trigger.  Once all commands have been
1752  *	either invoked or set their return flag, the current record is
1753  *	either committed or discarded.  At that point, if any commands
1754  *	have deferred their triggers, those commands are finally
1755  *	invoked following the close of the current event.  In other
1756  *	words, if the event_trigger_ops @func() probe implementation
1757  *	itself logs to the trace buffer, this flag should be set,
1758  *	otherwise it can be left unspecified.
1759  *
1760  * @NEEDS_REC: A flag that says whether or not this command needs
1761  *	access to the trace record in order to perform its function,
1762  *	regardless of whether or not it has a filter associated with
1763  *	it (filters make a trigger require access to the trace record
1764  *	but are not always present).
1765  */
1766 enum event_command_flags {
1767 	EVENT_CMD_FL_POST_TRIGGER	= 1,
1768 	EVENT_CMD_FL_NEEDS_REC		= 2,
1769 };
1770 
1771 static inline bool event_command_post_trigger(struct event_command *cmd_ops)
1772 {
1773 	return cmd_ops->flags & EVENT_CMD_FL_POST_TRIGGER;
1774 }
1775 
1776 static inline bool event_command_needs_rec(struct event_command *cmd_ops)
1777 {
1778 	return cmd_ops->flags & EVENT_CMD_FL_NEEDS_REC;
1779 }
1780 
1781 extern int trace_event_enable_disable(struct trace_event_file *file,
1782 				      int enable, int soft_disable);
1783 extern int tracing_alloc_snapshot(void);
1784 extern void tracing_snapshot_cond(struct trace_array *tr, void *cond_data);
1785 extern int tracing_snapshot_cond_enable(struct trace_array *tr, void *cond_data, cond_update_fn_t update);
1786 
1787 extern int tracing_snapshot_cond_disable(struct trace_array *tr);
1788 extern void *tracing_cond_snapshot_data(struct trace_array *tr);
1789 
1790 extern const char *__start___trace_bprintk_fmt[];
1791 extern const char *__stop___trace_bprintk_fmt[];
1792 
1793 extern const char *__start___tracepoint_str[];
1794 extern const char *__stop___tracepoint_str[];
1795 
1796 void trace_printk_control(bool enabled);
1797 void trace_printk_start_comm(void);
1798 int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set);
1799 int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled);
1800 
1801 /* Used from boot time tracer */
1802 extern int trace_set_options(struct trace_array *tr, char *option);
1803 extern int tracing_set_tracer(struct trace_array *tr, const char *buf);
1804 extern ssize_t tracing_resize_ring_buffer(struct trace_array *tr,
1805 					  unsigned long size, int cpu_id);
1806 extern int tracing_set_cpumask(struct trace_array *tr,
1807 				cpumask_var_t tracing_cpumask_new);
1808 
1809 
1810 #define MAX_EVENT_NAME_LEN	64
1811 
1812 extern ssize_t trace_parse_run_command(struct file *file,
1813 		const char __user *buffer, size_t count, loff_t *ppos,
1814 		int (*createfn)(const char *));
1815 
1816 extern unsigned int err_pos(char *cmd, const char *str);
1817 extern void tracing_log_err(struct trace_array *tr,
1818 			    const char *loc, const char *cmd,
1819 			    const char **errs, u8 type, u8 pos);
1820 
1821 /*
1822  * Normal trace_printk() and friends allocates special buffers
1823  * to do the manipulation, as well as saves the print formats
1824  * into sections to display. But the trace infrastructure wants
1825  * to use these without the added overhead at the price of being
1826  * a bit slower (used mainly for warnings, where we don't care
1827  * about performance). The internal_trace_puts() is for such
1828  * a purpose.
1829  */
1830 #define internal_trace_puts(str) __trace_puts(_THIS_IP_, str, strlen(str))
1831 
1832 #undef FTRACE_ENTRY
1833 #define FTRACE_ENTRY(call, struct_name, id, tstruct, print)	\
1834 	extern struct trace_event_call					\
1835 	__aligned(4) event_##call;
1836 #undef FTRACE_ENTRY_DUP
1837 #define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print)	\
1838 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
1839 #undef FTRACE_ENTRY_PACKED
1840 #define FTRACE_ENTRY_PACKED(call, struct_name, id, tstruct, print) \
1841 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
1842 
1843 #include "trace_entries.h"
1844 
1845 #if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_FUNCTION_TRACER)
1846 int perf_ftrace_event_register(struct trace_event_call *call,
1847 			       enum trace_reg type, void *data);
1848 #else
1849 #define perf_ftrace_event_register NULL
1850 #endif
1851 
1852 #ifdef CONFIG_FTRACE_SYSCALLS
1853 void init_ftrace_syscalls(void);
1854 const char *get_syscall_name(int syscall);
1855 #else
1856 static inline void init_ftrace_syscalls(void) { }
1857 static inline const char *get_syscall_name(int syscall)
1858 {
1859 	return NULL;
1860 }
1861 #endif
1862 
1863 #ifdef CONFIG_EVENT_TRACING
1864 void trace_event_init(void);
1865 void trace_event_eval_update(struct trace_eval_map **map, int len);
1866 /* Used from boot time tracer */
1867 extern int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set);
1868 extern int trigger_process_regex(struct trace_event_file *file, char *buff);
1869 #else
1870 static inline void __init trace_event_init(void) { }
1871 static inline void trace_event_eval_update(struct trace_eval_map **map, int len) { }
1872 #endif
1873 
1874 #ifdef CONFIG_TRACER_SNAPSHOT
1875 void tracing_snapshot_instance(struct trace_array *tr);
1876 int tracing_alloc_snapshot_instance(struct trace_array *tr);
1877 #else
1878 static inline void tracing_snapshot_instance(struct trace_array *tr) { }
1879 static inline int tracing_alloc_snapshot_instance(struct trace_array *tr)
1880 {
1881 	return 0;
1882 }
1883 #endif
1884 
1885 #ifdef CONFIG_PREEMPT_TRACER
1886 void tracer_preempt_on(unsigned long a0, unsigned long a1);
1887 void tracer_preempt_off(unsigned long a0, unsigned long a1);
1888 #else
1889 static inline void tracer_preempt_on(unsigned long a0, unsigned long a1) { }
1890 static inline void tracer_preempt_off(unsigned long a0, unsigned long a1) { }
1891 #endif
1892 #ifdef CONFIG_IRQSOFF_TRACER
1893 void tracer_hardirqs_on(unsigned long a0, unsigned long a1);
1894 void tracer_hardirqs_off(unsigned long a0, unsigned long a1);
1895 #else
1896 static inline void tracer_hardirqs_on(unsigned long a0, unsigned long a1) { }
1897 static inline void tracer_hardirqs_off(unsigned long a0, unsigned long a1) { }
1898 #endif
1899 
1900 extern struct trace_iterator *tracepoint_print_iter;
1901 
1902 /*
1903  * Reset the state of the trace_iterator so that it can read consumed data.
1904  * Normally, the trace_iterator is used for reading the data when it is not
1905  * consumed, and must retain state.
1906  */
1907 static __always_inline void trace_iterator_reset(struct trace_iterator *iter)
1908 {
1909 	const size_t offset = offsetof(struct trace_iterator, seq);
1910 
1911 	/*
1912 	 * Keep gcc from complaining about overwriting more than just one
1913 	 * member in the structure.
1914 	 */
1915 	memset((char *)iter + offset, 0, sizeof(struct trace_iterator) - offset);
1916 
1917 	iter->pos = -1;
1918 }
1919 
1920 /* Check the name is good for event/group/fields */
1921 static inline bool is_good_name(const char *name)
1922 {
1923 	if (!isalpha(*name) && *name != '_')
1924 		return false;
1925 	while (*++name != '\0') {
1926 		if (!isalpha(*name) && !isdigit(*name) && *name != '_')
1927 			return false;
1928 	}
1929 	return true;
1930 }
1931 
1932 #endif /* _LINUX_KERNEL_TRACE_H */
1933