xref: /openbmc/linux/kernel/trace/trace.h (revision e3d786a3)
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/hw_breakpoint.h>
15 #include <linux/trace_seq.h>
16 #include <linux/trace_events.h>
17 #include <linux/compiler.h>
18 #include <linux/trace_seq.h>
19 #include <linux/glob.h>
20 
21 #ifdef CONFIG_FTRACE_SYSCALLS
22 #include <asm/unistd.h>		/* For NR_SYSCALLS	     */
23 #include <asm/syscall.h>	/* some archs define it here */
24 #endif
25 
26 enum trace_type {
27 	__TRACE_FIRST_TYPE = 0,
28 
29 	TRACE_FN,
30 	TRACE_CTX,
31 	TRACE_WAKE,
32 	TRACE_STACK,
33 	TRACE_PRINT,
34 	TRACE_BPRINT,
35 	TRACE_MMIO_RW,
36 	TRACE_MMIO_MAP,
37 	TRACE_BRANCH,
38 	TRACE_GRAPH_RET,
39 	TRACE_GRAPH_ENT,
40 	TRACE_USER_STACK,
41 	TRACE_BLK,
42 	TRACE_BPUTS,
43 	TRACE_HWLAT,
44 	TRACE_RAW_DATA,
45 
46 	__TRACE_LAST_TYPE,
47 };
48 
49 
50 #undef __field
51 #define __field(type, item)		type	item;
52 
53 #undef __field_struct
54 #define __field_struct(type, item)	__field(type, item)
55 
56 #undef __field_desc
57 #define __field_desc(type, container, item)
58 
59 #undef __array
60 #define __array(type, item, size)	type	item[size];
61 
62 #undef __array_desc
63 #define __array_desc(type, container, item, size)
64 
65 #undef __dynamic_array
66 #define __dynamic_array(type, item)	type	item[];
67 
68 #undef F_STRUCT
69 #define F_STRUCT(args...)		args
70 
71 #undef FTRACE_ENTRY
72 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print, filter)	\
73 	struct struct_name {						\
74 		struct trace_entry	ent;				\
75 		tstruct							\
76 	}
77 
78 #undef FTRACE_ENTRY_DUP
79 #define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk, filter)
80 
81 #undef FTRACE_ENTRY_REG
82 #define FTRACE_ENTRY_REG(name, struct_name, id, tstruct, print,	\
83 			 filter, regfn) \
84 	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print), \
85 		     filter)
86 
87 #undef FTRACE_ENTRY_PACKED
88 #define FTRACE_ENTRY_PACKED(name, struct_name, id, tstruct, print,	\
89 			    filter)					\
90 	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print), \
91 		     filter) __packed
92 
93 #include "trace_entries.h"
94 
95 /*
96  * syscalls are special, and need special handling, this is why
97  * they are not included in trace_entries.h
98  */
99 struct syscall_trace_enter {
100 	struct trace_entry	ent;
101 	int			nr;
102 	unsigned long		args[];
103 };
104 
105 struct syscall_trace_exit {
106 	struct trace_entry	ent;
107 	int			nr;
108 	long			ret;
109 };
110 
111 struct kprobe_trace_entry_head {
112 	struct trace_entry	ent;
113 	unsigned long		ip;
114 };
115 
116 struct kretprobe_trace_entry_head {
117 	struct trace_entry	ent;
118 	unsigned long		func;
119 	unsigned long		ret_ip;
120 };
121 
122 /*
123  * trace_flag_type is an enumeration that holds different
124  * states when a trace occurs. These are:
125  *  IRQS_OFF		- interrupts were disabled
126  *  IRQS_NOSUPPORT	- arch does not support irqs_disabled_flags
127  *  NEED_RESCHED	- reschedule is requested
128  *  HARDIRQ		- inside an interrupt handler
129  *  SOFTIRQ		- inside a softirq handler
130  */
131 enum trace_flag_type {
132 	TRACE_FLAG_IRQS_OFF		= 0x01,
133 	TRACE_FLAG_IRQS_NOSUPPORT	= 0x02,
134 	TRACE_FLAG_NEED_RESCHED		= 0x04,
135 	TRACE_FLAG_HARDIRQ		= 0x08,
136 	TRACE_FLAG_SOFTIRQ		= 0x10,
137 	TRACE_FLAG_PREEMPT_RESCHED	= 0x20,
138 	TRACE_FLAG_NMI			= 0x40,
139 };
140 
141 #define TRACE_BUF_SIZE		1024
142 
143 struct trace_array;
144 
145 /*
146  * The CPU trace array - it consists of thousands of trace entries
147  * plus some other descriptor data: (for example which task started
148  * the trace, etc.)
149  */
150 struct trace_array_cpu {
151 	atomic_t		disabled;
152 	void			*buffer_page;	/* ring buffer spare */
153 
154 	unsigned long		entries;
155 	unsigned long		saved_latency;
156 	unsigned long		critical_start;
157 	unsigned long		critical_end;
158 	unsigned long		critical_sequence;
159 	unsigned long		nice;
160 	unsigned long		policy;
161 	unsigned long		rt_priority;
162 	unsigned long		skipped_entries;
163 	u64			preempt_timestamp;
164 	pid_t			pid;
165 	kuid_t			uid;
166 	char			comm[TASK_COMM_LEN];
167 
168 	bool			ignore_pid;
169 #ifdef CONFIG_FUNCTION_TRACER
170 	bool			ftrace_ignore_pid;
171 #endif
172 };
173 
174 struct tracer;
175 struct trace_option_dentry;
176 
177 struct trace_buffer {
178 	struct trace_array		*tr;
179 	struct ring_buffer		*buffer;
180 	struct trace_array_cpu __percpu	*data;
181 	u64				time_start;
182 	int				cpu;
183 };
184 
185 #define TRACE_FLAGS_MAX_SIZE		32
186 
187 struct trace_options {
188 	struct tracer			*tracer;
189 	struct trace_option_dentry	*topts;
190 };
191 
192 struct trace_pid_list {
193 	int				pid_max;
194 	unsigned long			*pids;
195 };
196 
197 /*
198  * The trace array - an array of per-CPU trace arrays. This is the
199  * highest level data structure that individual tracers deal with.
200  * They have on/off state as well:
201  */
202 struct trace_array {
203 	struct list_head	list;
204 	char			*name;
205 	struct trace_buffer	trace_buffer;
206 #ifdef CONFIG_TRACER_MAX_TRACE
207 	/*
208 	 * The max_buffer is used to snapshot the trace when a maximum
209 	 * latency is reached, or when the user initiates a snapshot.
210 	 * Some tracers will use this to store a maximum trace while
211 	 * it continues examining live traces.
212 	 *
213 	 * The buffers for the max_buffer are set up the same as the trace_buffer
214 	 * When a snapshot is taken, the buffer of the max_buffer is swapped
215 	 * with the buffer of the trace_buffer and the buffers are reset for
216 	 * the trace_buffer so the tracing can continue.
217 	 */
218 	struct trace_buffer	max_buffer;
219 	bool			allocated_snapshot;
220 #endif
221 #if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)
222 	unsigned long		max_latency;
223 #endif
224 	struct trace_pid_list	__rcu *filtered_pids;
225 	/*
226 	 * max_lock is used to protect the swapping of buffers
227 	 * when taking a max snapshot. The buffers themselves are
228 	 * protected by per_cpu spinlocks. But the action of the swap
229 	 * needs its own lock.
230 	 *
231 	 * This is defined as a arch_spinlock_t in order to help
232 	 * with performance when lockdep debugging is enabled.
233 	 *
234 	 * It is also used in other places outside the update_max_tr
235 	 * so it needs to be defined outside of the
236 	 * CONFIG_TRACER_MAX_TRACE.
237 	 */
238 	arch_spinlock_t		max_lock;
239 	int			buffer_disabled;
240 #ifdef CONFIG_FTRACE_SYSCALLS
241 	int			sys_refcount_enter;
242 	int			sys_refcount_exit;
243 	struct trace_event_file __rcu *enter_syscall_files[NR_syscalls];
244 	struct trace_event_file __rcu *exit_syscall_files[NR_syscalls];
245 #endif
246 	int			stop_count;
247 	int			clock_id;
248 	int			nr_topts;
249 	bool			clear_trace;
250 	struct tracer		*current_trace;
251 	unsigned int		trace_flags;
252 	unsigned char		trace_flags_index[TRACE_FLAGS_MAX_SIZE];
253 	unsigned int		flags;
254 	raw_spinlock_t		start_lock;
255 	struct dentry		*dir;
256 	struct dentry		*options;
257 	struct dentry		*percpu_dir;
258 	struct dentry		*event_dir;
259 	struct trace_options	*topts;
260 	struct list_head	systems;
261 	struct list_head	events;
262 	struct trace_event_file *trace_marker_file;
263 	cpumask_var_t		tracing_cpumask; /* only trace on set CPUs */
264 	int			ref;
265 #ifdef CONFIG_FUNCTION_TRACER
266 	struct ftrace_ops	*ops;
267 	struct trace_pid_list	__rcu *function_pids;
268 #ifdef CONFIG_DYNAMIC_FTRACE
269 	/* All of these are protected by the ftrace_lock */
270 	struct list_head	func_probes;
271 	struct list_head	mod_trace;
272 	struct list_head	mod_notrace;
273 #endif
274 	/* function tracing enabled */
275 	int			function_enabled;
276 #endif
277 	int			time_stamp_abs_ref;
278 	struct list_head	hist_vars;
279 };
280 
281 enum {
282 	TRACE_ARRAY_FL_GLOBAL	= (1 << 0)
283 };
284 
285 extern struct list_head ftrace_trace_arrays;
286 
287 extern struct mutex trace_types_lock;
288 
289 extern int trace_array_get(struct trace_array *tr);
290 extern void trace_array_put(struct trace_array *tr);
291 
292 extern int tracing_set_time_stamp_abs(struct trace_array *tr, bool abs);
293 extern int tracing_set_clock(struct trace_array *tr, const char *clockstr);
294 
295 extern bool trace_clock_in_ns(struct trace_array *tr);
296 
297 /*
298  * The global tracer (top) should be the first trace array added,
299  * but we check the flag anyway.
300  */
301 static inline struct trace_array *top_trace_array(void)
302 {
303 	struct trace_array *tr;
304 
305 	if (list_empty(&ftrace_trace_arrays))
306 		return NULL;
307 
308 	tr = list_entry(ftrace_trace_arrays.prev,
309 			typeof(*tr), list);
310 	WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
311 	return tr;
312 }
313 
314 #define FTRACE_CMP_TYPE(var, type) \
315 	__builtin_types_compatible_p(typeof(var), type *)
316 
317 #undef IF_ASSIGN
318 #define IF_ASSIGN(var, entry, etype, id)		\
319 	if (FTRACE_CMP_TYPE(var, etype)) {		\
320 		var = (typeof(var))(entry);		\
321 		WARN_ON(id && (entry)->type != id);	\
322 		break;					\
323 	}
324 
325 /* Will cause compile errors if type is not found. */
326 extern void __ftrace_bad_type(void);
327 
328 /*
329  * The trace_assign_type is a verifier that the entry type is
330  * the same as the type being assigned. To add new types simply
331  * add a line with the following format:
332  *
333  * IF_ASSIGN(var, ent, type, id);
334  *
335  *  Where "type" is the trace type that includes the trace_entry
336  *  as the "ent" item. And "id" is the trace identifier that is
337  *  used in the trace_type enum.
338  *
339  *  If the type can have more than one id, then use zero.
340  */
341 #define trace_assign_type(var, ent)					\
342 	do {								\
343 		IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);	\
344 		IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);	\
345 		IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);	\
346 		IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
347 		IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);	\
348 		IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT);	\
349 		IF_ASSIGN(var, ent, struct bputs_entry, TRACE_BPUTS);	\
350 		IF_ASSIGN(var, ent, struct hwlat_entry, TRACE_HWLAT);	\
351 		IF_ASSIGN(var, ent, struct raw_data_entry, TRACE_RAW_DATA);\
352 		IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,		\
353 			  TRACE_MMIO_RW);				\
354 		IF_ASSIGN(var, ent, struct trace_mmiotrace_map,		\
355 			  TRACE_MMIO_MAP);				\
356 		IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
357 		IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,	\
358 			  TRACE_GRAPH_ENT);		\
359 		IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,	\
360 			  TRACE_GRAPH_RET);		\
361 		__ftrace_bad_type();					\
362 	} while (0)
363 
364 /*
365  * An option specific to a tracer. This is a boolean value.
366  * The bit is the bit index that sets its value on the
367  * flags value in struct tracer_flags.
368  */
369 struct tracer_opt {
370 	const char	*name; /* Will appear on the trace_options file */
371 	u32		bit; /* Mask assigned in val field in tracer_flags */
372 };
373 
374 /*
375  * The set of specific options for a tracer. Your tracer
376  * have to set the initial value of the flags val.
377  */
378 struct tracer_flags {
379 	u32			val;
380 	struct tracer_opt	*opts;
381 	struct tracer		*trace;
382 };
383 
384 /* Makes more easy to define a tracer opt */
385 #define TRACER_OPT(s, b)	.name = #s, .bit = b
386 
387 
388 struct trace_option_dentry {
389 	struct tracer_opt		*opt;
390 	struct tracer_flags		*flags;
391 	struct trace_array		*tr;
392 	struct dentry			*entry;
393 };
394 
395 /**
396  * struct tracer - a specific tracer and its callbacks to interact with tracefs
397  * @name: the name chosen to select it on the available_tracers file
398  * @init: called when one switches to this tracer (echo name > current_tracer)
399  * @reset: called when one switches to another tracer
400  * @start: called when tracing is unpaused (echo 1 > tracing_on)
401  * @stop: called when tracing is paused (echo 0 > tracing_on)
402  * @update_thresh: called when tracing_thresh is updated
403  * @open: called when the trace file is opened
404  * @pipe_open: called when the trace_pipe file is opened
405  * @close: called when the trace file is released
406  * @pipe_close: called when the trace_pipe file is released
407  * @read: override the default read callback on trace_pipe
408  * @splice_read: override the default splice_read callback on trace_pipe
409  * @selftest: selftest to run on boot (see trace_selftest.c)
410  * @print_headers: override the first lines that describe your columns
411  * @print_line: callback that prints a trace
412  * @set_flag: signals one of your private flags changed (trace_options file)
413  * @flags: your private flags
414  */
415 struct tracer {
416 	const char		*name;
417 	int			(*init)(struct trace_array *tr);
418 	void			(*reset)(struct trace_array *tr);
419 	void			(*start)(struct trace_array *tr);
420 	void			(*stop)(struct trace_array *tr);
421 	int			(*update_thresh)(struct trace_array *tr);
422 	void			(*open)(struct trace_iterator *iter);
423 	void			(*pipe_open)(struct trace_iterator *iter);
424 	void			(*close)(struct trace_iterator *iter);
425 	void			(*pipe_close)(struct trace_iterator *iter);
426 	ssize_t			(*read)(struct trace_iterator *iter,
427 					struct file *filp, char __user *ubuf,
428 					size_t cnt, loff_t *ppos);
429 	ssize_t			(*splice_read)(struct trace_iterator *iter,
430 					       struct file *filp,
431 					       loff_t *ppos,
432 					       struct pipe_inode_info *pipe,
433 					       size_t len,
434 					       unsigned int flags);
435 #ifdef CONFIG_FTRACE_STARTUP_TEST
436 	int			(*selftest)(struct tracer *trace,
437 					    struct trace_array *tr);
438 #endif
439 	void			(*print_header)(struct seq_file *m);
440 	enum print_line_t	(*print_line)(struct trace_iterator *iter);
441 	/* If you handled the flag setting, return 0 */
442 	int			(*set_flag)(struct trace_array *tr,
443 					    u32 old_flags, u32 bit, int set);
444 	/* Return 0 if OK with change, else return non-zero */
445 	int			(*flag_changed)(struct trace_array *tr,
446 						u32 mask, int set);
447 	struct tracer		*next;
448 	struct tracer_flags	*flags;
449 	int			enabled;
450 	int			ref;
451 	bool			print_max;
452 	bool			allow_instances;
453 #ifdef CONFIG_TRACER_MAX_TRACE
454 	bool			use_max_tr;
455 #endif
456 	/* True if tracer cannot be enabled in kernel param */
457 	bool			noboot;
458 };
459 
460 
461 /* Only current can touch trace_recursion */
462 
463 /*
464  * For function tracing recursion:
465  *  The order of these bits are important.
466  *
467  *  When function tracing occurs, the following steps are made:
468  *   If arch does not support a ftrace feature:
469  *    call internal function (uses INTERNAL bits) which calls...
470  *   If callback is registered to the "global" list, the list
471  *    function is called and recursion checks the GLOBAL bits.
472  *    then this function calls...
473  *   The function callback, which can use the FTRACE bits to
474  *    check for recursion.
475  *
476  * Now if the arch does not suppport a feature, and it calls
477  * the global list function which calls the ftrace callback
478  * all three of these steps will do a recursion protection.
479  * There's no reason to do one if the previous caller already
480  * did. The recursion that we are protecting against will
481  * go through the same steps again.
482  *
483  * To prevent the multiple recursion checks, if a recursion
484  * bit is set that is higher than the MAX bit of the current
485  * check, then we know that the check was made by the previous
486  * caller, and we can skip the current check.
487  */
488 enum {
489 	TRACE_BUFFER_BIT,
490 	TRACE_BUFFER_NMI_BIT,
491 	TRACE_BUFFER_IRQ_BIT,
492 	TRACE_BUFFER_SIRQ_BIT,
493 
494 	/* Start of function recursion bits */
495 	TRACE_FTRACE_BIT,
496 	TRACE_FTRACE_NMI_BIT,
497 	TRACE_FTRACE_IRQ_BIT,
498 	TRACE_FTRACE_SIRQ_BIT,
499 
500 	/* INTERNAL_BITs must be greater than FTRACE_BITs */
501 	TRACE_INTERNAL_BIT,
502 	TRACE_INTERNAL_NMI_BIT,
503 	TRACE_INTERNAL_IRQ_BIT,
504 	TRACE_INTERNAL_SIRQ_BIT,
505 
506 	TRACE_BRANCH_BIT,
507 /*
508  * Abuse of the trace_recursion.
509  * As we need a way to maintain state if we are tracing the function
510  * graph in irq because we want to trace a particular function that
511  * was called in irq context but we have irq tracing off. Since this
512  * can only be modified by current, we can reuse trace_recursion.
513  */
514 	TRACE_IRQ_BIT,
515 };
516 
517 #define trace_recursion_set(bit)	do { (current)->trace_recursion |= (1<<(bit)); } while (0)
518 #define trace_recursion_clear(bit)	do { (current)->trace_recursion &= ~(1<<(bit)); } while (0)
519 #define trace_recursion_test(bit)	((current)->trace_recursion & (1<<(bit)))
520 
521 #define TRACE_CONTEXT_BITS	4
522 
523 #define TRACE_FTRACE_START	TRACE_FTRACE_BIT
524 #define TRACE_FTRACE_MAX	((1 << (TRACE_FTRACE_START + TRACE_CONTEXT_BITS)) - 1)
525 
526 #define TRACE_LIST_START	TRACE_INTERNAL_BIT
527 #define TRACE_LIST_MAX		((1 << (TRACE_LIST_START + TRACE_CONTEXT_BITS)) - 1)
528 
529 #define TRACE_CONTEXT_MASK	TRACE_LIST_MAX
530 
531 static __always_inline int trace_get_context_bit(void)
532 {
533 	int bit;
534 
535 	if (in_interrupt()) {
536 		if (in_nmi())
537 			bit = 0;
538 
539 		else if (in_irq())
540 			bit = 1;
541 		else
542 			bit = 2;
543 	} else
544 		bit = 3;
545 
546 	return bit;
547 }
548 
549 static __always_inline int trace_test_and_set_recursion(int start, int max)
550 {
551 	unsigned int val = current->trace_recursion;
552 	int bit;
553 
554 	/* A previous recursion check was made */
555 	if ((val & TRACE_CONTEXT_MASK) > max)
556 		return 0;
557 
558 	bit = trace_get_context_bit() + start;
559 	if (unlikely(val & (1 << bit)))
560 		return -1;
561 
562 	val |= 1 << bit;
563 	current->trace_recursion = val;
564 	barrier();
565 
566 	return bit;
567 }
568 
569 static __always_inline void trace_clear_recursion(int bit)
570 {
571 	unsigned int val = current->trace_recursion;
572 
573 	if (!bit)
574 		return;
575 
576 	bit = 1 << bit;
577 	val &= ~bit;
578 
579 	barrier();
580 	current->trace_recursion = val;
581 }
582 
583 static inline struct ring_buffer_iter *
584 trace_buffer_iter(struct trace_iterator *iter, int cpu)
585 {
586 	return iter->buffer_iter ? iter->buffer_iter[cpu] : NULL;
587 }
588 
589 int tracer_init(struct tracer *t, struct trace_array *tr);
590 int tracing_is_enabled(void);
591 void tracing_reset(struct trace_buffer *buf, int cpu);
592 void tracing_reset_online_cpus(struct trace_buffer *buf);
593 void tracing_reset_current(int cpu);
594 void tracing_reset_all_online_cpus(void);
595 int tracing_open_generic(struct inode *inode, struct file *filp);
596 bool tracing_is_disabled(void);
597 bool tracer_tracing_is_on(struct trace_array *tr);
598 void tracer_tracing_on(struct trace_array *tr);
599 void tracer_tracing_off(struct trace_array *tr);
600 struct dentry *trace_create_file(const char *name,
601 				 umode_t mode,
602 				 struct dentry *parent,
603 				 void *data,
604 				 const struct file_operations *fops);
605 
606 struct dentry *tracing_init_dentry(void);
607 
608 struct ring_buffer_event;
609 
610 struct ring_buffer_event *
611 trace_buffer_lock_reserve(struct ring_buffer *buffer,
612 			  int type,
613 			  unsigned long len,
614 			  unsigned long flags,
615 			  int pc);
616 
617 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
618 						struct trace_array_cpu *data);
619 
620 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
621 					  int *ent_cpu, u64 *ent_ts);
622 
623 void trace_buffer_unlock_commit_nostack(struct ring_buffer *buffer,
624 					struct ring_buffer_event *event);
625 
626 int trace_empty(struct trace_iterator *iter);
627 
628 void *trace_find_next_entry_inc(struct trace_iterator *iter);
629 
630 void trace_init_global_iter(struct trace_iterator *iter);
631 
632 void tracing_iter_reset(struct trace_iterator *iter, int cpu);
633 
634 void trace_function(struct trace_array *tr,
635 		    unsigned long ip,
636 		    unsigned long parent_ip,
637 		    unsigned long flags, int pc);
638 void trace_graph_function(struct trace_array *tr,
639 		    unsigned long ip,
640 		    unsigned long parent_ip,
641 		    unsigned long flags, int pc);
642 void trace_latency_header(struct seq_file *m);
643 void trace_default_header(struct seq_file *m);
644 void print_trace_header(struct seq_file *m, struct trace_iterator *iter);
645 int trace_empty(struct trace_iterator *iter);
646 
647 void trace_graph_return(struct ftrace_graph_ret *trace);
648 int trace_graph_entry(struct ftrace_graph_ent *trace);
649 void set_graph_array(struct trace_array *tr);
650 
651 void tracing_start_cmdline_record(void);
652 void tracing_stop_cmdline_record(void);
653 void tracing_start_tgid_record(void);
654 void tracing_stop_tgid_record(void);
655 
656 int register_tracer(struct tracer *type);
657 int is_tracing_stopped(void);
658 
659 loff_t tracing_lseek(struct file *file, loff_t offset, int whence);
660 
661 extern cpumask_var_t __read_mostly tracing_buffer_mask;
662 
663 #define for_each_tracing_cpu(cpu)	\
664 	for_each_cpu(cpu, tracing_buffer_mask)
665 
666 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
667 
668 extern unsigned long tracing_thresh;
669 
670 /* PID filtering */
671 
672 extern int pid_max;
673 
674 bool trace_find_filtered_pid(struct trace_pid_list *filtered_pids,
675 			     pid_t search_pid);
676 bool trace_ignore_this_task(struct trace_pid_list *filtered_pids,
677 			    struct task_struct *task);
678 void trace_filter_add_remove_task(struct trace_pid_list *pid_list,
679 				  struct task_struct *self,
680 				  struct task_struct *task);
681 void *trace_pid_next(struct trace_pid_list *pid_list, void *v, loff_t *pos);
682 void *trace_pid_start(struct trace_pid_list *pid_list, loff_t *pos);
683 int trace_pid_show(struct seq_file *m, void *v);
684 void trace_free_pid_list(struct trace_pid_list *pid_list);
685 int trace_pid_write(struct trace_pid_list *filtered_pids,
686 		    struct trace_pid_list **new_pid_list,
687 		    const char __user *ubuf, size_t cnt);
688 
689 #ifdef CONFIG_TRACER_MAX_TRACE
690 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
691 void update_max_tr_single(struct trace_array *tr,
692 			  struct task_struct *tsk, int cpu);
693 #endif /* CONFIG_TRACER_MAX_TRACE */
694 
695 #ifdef CONFIG_STACKTRACE
696 void ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags,
697 			    int pc);
698 
699 void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
700 		   int pc);
701 #else
702 static inline void ftrace_trace_userstack(struct ring_buffer *buffer,
703 					  unsigned long flags, int pc)
704 {
705 }
706 
707 static inline void __trace_stack(struct trace_array *tr, unsigned long flags,
708 				 int skip, int pc)
709 {
710 }
711 #endif /* CONFIG_STACKTRACE */
712 
713 extern u64 ftrace_now(int cpu);
714 
715 extern void trace_find_cmdline(int pid, char comm[]);
716 extern int trace_find_tgid(int pid);
717 extern void trace_event_follow_fork(struct trace_array *tr, bool enable);
718 
719 #ifdef CONFIG_DYNAMIC_FTRACE
720 extern unsigned long ftrace_update_tot_cnt;
721 void ftrace_init_trace_array(struct trace_array *tr);
722 #else
723 static inline void ftrace_init_trace_array(struct trace_array *tr) { }
724 #endif
725 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
726 extern int DYN_FTRACE_TEST_NAME(void);
727 #define DYN_FTRACE_TEST_NAME2 trace_selftest_dynamic_test_func2
728 extern int DYN_FTRACE_TEST_NAME2(void);
729 
730 extern bool ring_buffer_expanded;
731 extern bool tracing_selftest_disabled;
732 
733 #ifdef CONFIG_FTRACE_STARTUP_TEST
734 extern int trace_selftest_startup_function(struct tracer *trace,
735 					   struct trace_array *tr);
736 extern int trace_selftest_startup_function_graph(struct tracer *trace,
737 						 struct trace_array *tr);
738 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
739 					  struct trace_array *tr);
740 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
741 					     struct trace_array *tr);
742 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
743 						 struct trace_array *tr);
744 extern int trace_selftest_startup_wakeup(struct tracer *trace,
745 					 struct trace_array *tr);
746 extern int trace_selftest_startup_nop(struct tracer *trace,
747 					 struct trace_array *tr);
748 extern int trace_selftest_startup_branch(struct tracer *trace,
749 					 struct trace_array *tr);
750 /*
751  * Tracer data references selftest functions that only occur
752  * on boot up. These can be __init functions. Thus, when selftests
753  * are enabled, then the tracers need to reference __init functions.
754  */
755 #define __tracer_data		__refdata
756 #else
757 /* Tracers are seldom changed. Optimize when selftests are disabled. */
758 #define __tracer_data		__read_mostly
759 #endif /* CONFIG_FTRACE_STARTUP_TEST */
760 
761 extern void *head_page(struct trace_array_cpu *data);
762 extern unsigned long long ns2usecs(u64 nsec);
763 extern int
764 trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
765 extern int
766 trace_vprintk(unsigned long ip, const char *fmt, va_list args);
767 extern int
768 trace_array_vprintk(struct trace_array *tr,
769 		    unsigned long ip, const char *fmt, va_list args);
770 int trace_array_printk(struct trace_array *tr,
771 		       unsigned long ip, const char *fmt, ...);
772 int trace_array_printk_buf(struct ring_buffer *buffer,
773 			   unsigned long ip, const char *fmt, ...);
774 void trace_printk_seq(struct trace_seq *s);
775 enum print_line_t print_trace_line(struct trace_iterator *iter);
776 
777 extern char trace_find_mark(unsigned long long duration);
778 
779 struct ftrace_hash;
780 
781 struct ftrace_mod_load {
782 	struct list_head	list;
783 	char			*func;
784 	char			*module;
785 	int			 enable;
786 };
787 
788 enum {
789 	FTRACE_HASH_FL_MOD	= (1 << 0),
790 };
791 
792 struct ftrace_hash {
793 	unsigned long		size_bits;
794 	struct hlist_head	*buckets;
795 	unsigned long		count;
796 	unsigned long		flags;
797 	struct rcu_head		rcu;
798 };
799 
800 struct ftrace_func_entry *
801 ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip);
802 
803 static __always_inline bool ftrace_hash_empty(struct ftrace_hash *hash)
804 {
805 	return !hash || !(hash->count || (hash->flags & FTRACE_HASH_FL_MOD));
806 }
807 
808 /* Standard output formatting function used for function return traces */
809 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
810 
811 /* Flag options */
812 #define TRACE_GRAPH_PRINT_OVERRUN       0x1
813 #define TRACE_GRAPH_PRINT_CPU           0x2
814 #define TRACE_GRAPH_PRINT_OVERHEAD      0x4
815 #define TRACE_GRAPH_PRINT_PROC          0x8
816 #define TRACE_GRAPH_PRINT_DURATION      0x10
817 #define TRACE_GRAPH_PRINT_ABS_TIME      0x20
818 #define TRACE_GRAPH_PRINT_IRQS          0x40
819 #define TRACE_GRAPH_PRINT_TAIL          0x80
820 #define TRACE_GRAPH_SLEEP_TIME		0x100
821 #define TRACE_GRAPH_GRAPH_TIME		0x200
822 #define TRACE_GRAPH_PRINT_FILL_SHIFT	28
823 #define TRACE_GRAPH_PRINT_FILL_MASK	(0x3 << TRACE_GRAPH_PRINT_FILL_SHIFT)
824 
825 extern void ftrace_graph_sleep_time_control(bool enable);
826 extern void ftrace_graph_graph_time_control(bool enable);
827 
828 extern enum print_line_t
829 print_graph_function_flags(struct trace_iterator *iter, u32 flags);
830 extern void print_graph_headers_flags(struct seq_file *s, u32 flags);
831 extern void
832 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
833 extern void graph_trace_open(struct trace_iterator *iter);
834 extern void graph_trace_close(struct trace_iterator *iter);
835 extern int __trace_graph_entry(struct trace_array *tr,
836 			       struct ftrace_graph_ent *trace,
837 			       unsigned long flags, int pc);
838 extern void __trace_graph_return(struct trace_array *tr,
839 				 struct ftrace_graph_ret *trace,
840 				 unsigned long flags, int pc);
841 
842 #ifdef CONFIG_DYNAMIC_FTRACE
843 extern struct ftrace_hash *ftrace_graph_hash;
844 extern struct ftrace_hash *ftrace_graph_notrace_hash;
845 
846 static inline int ftrace_graph_addr(unsigned long addr)
847 {
848 	int ret = 0;
849 
850 	preempt_disable_notrace();
851 
852 	if (ftrace_hash_empty(ftrace_graph_hash)) {
853 		ret = 1;
854 		goto out;
855 	}
856 
857 	if (ftrace_lookup_ip(ftrace_graph_hash, addr)) {
858 		/*
859 		 * If no irqs are to be traced, but a set_graph_function
860 		 * is set, and called by an interrupt handler, we still
861 		 * want to trace it.
862 		 */
863 		if (in_irq())
864 			trace_recursion_set(TRACE_IRQ_BIT);
865 		else
866 			trace_recursion_clear(TRACE_IRQ_BIT);
867 		ret = 1;
868 	}
869 
870 out:
871 	preempt_enable_notrace();
872 	return ret;
873 }
874 
875 static inline int ftrace_graph_notrace_addr(unsigned long addr)
876 {
877 	int ret = 0;
878 
879 	preempt_disable_notrace();
880 
881 	if (ftrace_lookup_ip(ftrace_graph_notrace_hash, addr))
882 		ret = 1;
883 
884 	preempt_enable_notrace();
885 	return ret;
886 }
887 #else
888 static inline int ftrace_graph_addr(unsigned long addr)
889 {
890 	return 1;
891 }
892 
893 static inline int ftrace_graph_notrace_addr(unsigned long addr)
894 {
895 	return 0;
896 }
897 #endif /* CONFIG_DYNAMIC_FTRACE */
898 
899 extern unsigned int fgraph_max_depth;
900 
901 static inline bool ftrace_graph_ignore_func(struct ftrace_graph_ent *trace)
902 {
903 	/* trace it when it is-nested-in or is a function enabled. */
904 	return !(trace->depth || ftrace_graph_addr(trace->func)) ||
905 		(trace->depth < 0) ||
906 		(fgraph_max_depth && trace->depth >= fgraph_max_depth);
907 }
908 
909 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
910 static inline enum print_line_t
911 print_graph_function_flags(struct trace_iterator *iter, u32 flags)
912 {
913 	return TRACE_TYPE_UNHANDLED;
914 }
915 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
916 
917 extern struct list_head ftrace_pids;
918 
919 #ifdef CONFIG_FUNCTION_TRACER
920 struct ftrace_func_command {
921 	struct list_head	list;
922 	char			*name;
923 	int			(*func)(struct trace_array *tr,
924 					struct ftrace_hash *hash,
925 					char *func, char *cmd,
926 					char *params, int enable);
927 };
928 extern bool ftrace_filter_param __initdata;
929 static inline int ftrace_trace_task(struct trace_array *tr)
930 {
931 	return !this_cpu_read(tr->trace_buffer.data->ftrace_ignore_pid);
932 }
933 extern int ftrace_is_dead(void);
934 int ftrace_create_function_files(struct trace_array *tr,
935 				 struct dentry *parent);
936 void ftrace_destroy_function_files(struct trace_array *tr);
937 void ftrace_init_global_array_ops(struct trace_array *tr);
938 void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func);
939 void ftrace_reset_array_ops(struct trace_array *tr);
940 void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer);
941 void ftrace_init_tracefs_toplevel(struct trace_array *tr,
942 				  struct dentry *d_tracer);
943 void ftrace_clear_pids(struct trace_array *tr);
944 int init_function_trace(void);
945 void ftrace_pid_follow_fork(struct trace_array *tr, bool enable);
946 #else
947 static inline int ftrace_trace_task(struct trace_array *tr)
948 {
949 	return 1;
950 }
951 static inline int ftrace_is_dead(void) { return 0; }
952 static inline int
953 ftrace_create_function_files(struct trace_array *tr,
954 			     struct dentry *parent)
955 {
956 	return 0;
957 }
958 static inline void ftrace_destroy_function_files(struct trace_array *tr) { }
959 static inline __init void
960 ftrace_init_global_array_ops(struct trace_array *tr) { }
961 static inline void ftrace_reset_array_ops(struct trace_array *tr) { }
962 static inline void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d) { }
963 static inline void ftrace_init_tracefs_toplevel(struct trace_array *tr, struct dentry *d) { }
964 static inline void ftrace_clear_pids(struct trace_array *tr) { }
965 static inline int init_function_trace(void) { return 0; }
966 static inline void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) { }
967 /* ftace_func_t type is not defined, use macro instead of static inline */
968 #define ftrace_init_array_ops(tr, func) do { } while (0)
969 #endif /* CONFIG_FUNCTION_TRACER */
970 
971 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
972 
973 struct ftrace_probe_ops {
974 	void			(*func)(unsigned long ip,
975 					unsigned long parent_ip,
976 					struct trace_array *tr,
977 					struct ftrace_probe_ops *ops,
978 					void *data);
979 	int			(*init)(struct ftrace_probe_ops *ops,
980 					struct trace_array *tr,
981 					unsigned long ip, void *init_data,
982 					void **data);
983 	void			(*free)(struct ftrace_probe_ops *ops,
984 					struct trace_array *tr,
985 					unsigned long ip, void *data);
986 	int			(*print)(struct seq_file *m,
987 					 unsigned long ip,
988 					 struct ftrace_probe_ops *ops,
989 					 void *data);
990 };
991 
992 struct ftrace_func_mapper;
993 typedef int (*ftrace_mapper_func)(void *data);
994 
995 struct ftrace_func_mapper *allocate_ftrace_func_mapper(void);
996 void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
997 					   unsigned long ip);
998 int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
999 			       unsigned long ip, void *data);
1000 void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
1001 				   unsigned long ip);
1002 void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
1003 			     ftrace_mapper_func free_func);
1004 
1005 extern int
1006 register_ftrace_function_probe(char *glob, struct trace_array *tr,
1007 			       struct ftrace_probe_ops *ops, void *data);
1008 extern int
1009 unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
1010 				      struct ftrace_probe_ops *ops);
1011 extern void clear_ftrace_function_probes(struct trace_array *tr);
1012 
1013 int register_ftrace_command(struct ftrace_func_command *cmd);
1014 int unregister_ftrace_command(struct ftrace_func_command *cmd);
1015 
1016 void ftrace_create_filter_files(struct ftrace_ops *ops,
1017 				struct dentry *parent);
1018 void ftrace_destroy_filter_files(struct ftrace_ops *ops);
1019 #else
1020 struct ftrace_func_command;
1021 
1022 static inline __init int register_ftrace_command(struct ftrace_func_command *cmd)
1023 {
1024 	return -EINVAL;
1025 }
1026 static inline __init int unregister_ftrace_command(char *cmd_name)
1027 {
1028 	return -EINVAL;
1029 }
1030 static inline void clear_ftrace_function_probes(struct trace_array *tr)
1031 {
1032 }
1033 
1034 /*
1035  * The ops parameter passed in is usually undefined.
1036  * This must be a macro.
1037  */
1038 #define ftrace_create_filter_files(ops, parent) do { } while (0)
1039 #define ftrace_destroy_filter_files(ops) do { } while (0)
1040 #endif /* CONFIG_FUNCTION_TRACER && CONFIG_DYNAMIC_FTRACE */
1041 
1042 bool ftrace_event_is_function(struct trace_event_call *call);
1043 
1044 /*
1045  * struct trace_parser - servers for reading the user input separated by spaces
1046  * @cont: set if the input is not complete - no final space char was found
1047  * @buffer: holds the parsed user input
1048  * @idx: user input length
1049  * @size: buffer size
1050  */
1051 struct trace_parser {
1052 	bool		cont;
1053 	char		*buffer;
1054 	unsigned	idx;
1055 	unsigned	size;
1056 };
1057 
1058 static inline bool trace_parser_loaded(struct trace_parser *parser)
1059 {
1060 	return (parser->idx != 0);
1061 }
1062 
1063 static inline bool trace_parser_cont(struct trace_parser *parser)
1064 {
1065 	return parser->cont;
1066 }
1067 
1068 static inline void trace_parser_clear(struct trace_parser *parser)
1069 {
1070 	parser->cont = false;
1071 	parser->idx = 0;
1072 }
1073 
1074 extern int trace_parser_get_init(struct trace_parser *parser, int size);
1075 extern void trace_parser_put(struct trace_parser *parser);
1076 extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
1077 	size_t cnt, loff_t *ppos);
1078 
1079 /*
1080  * Only create function graph options if function graph is configured.
1081  */
1082 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1083 # define FGRAPH_FLAGS						\
1084 		C(DISPLAY_GRAPH,	"display-graph"),
1085 #else
1086 # define FGRAPH_FLAGS
1087 #endif
1088 
1089 #ifdef CONFIG_BRANCH_TRACER
1090 # define BRANCH_FLAGS					\
1091 		C(BRANCH,		"branch"),
1092 #else
1093 # define BRANCH_FLAGS
1094 #endif
1095 
1096 #ifdef CONFIG_FUNCTION_TRACER
1097 # define FUNCTION_FLAGS						\
1098 		C(FUNCTION,		"function-trace"),	\
1099 		C(FUNC_FORK,		"function-fork"),
1100 # define FUNCTION_DEFAULT_FLAGS		TRACE_ITER_FUNCTION
1101 #else
1102 # define FUNCTION_FLAGS
1103 # define FUNCTION_DEFAULT_FLAGS		0UL
1104 # define TRACE_ITER_FUNC_FORK		0UL
1105 #endif
1106 
1107 #ifdef CONFIG_STACKTRACE
1108 # define STACK_FLAGS				\
1109 		C(STACKTRACE,		"stacktrace"),
1110 #else
1111 # define STACK_FLAGS
1112 #endif
1113 
1114 /*
1115  * trace_iterator_flags is an enumeration that defines bit
1116  * positions into trace_flags that controls the output.
1117  *
1118  * NOTE: These bits must match the trace_options array in
1119  *       trace.c (this macro guarantees it).
1120  */
1121 #define TRACE_FLAGS						\
1122 		C(PRINT_PARENT,		"print-parent"),	\
1123 		C(SYM_OFFSET,		"sym-offset"),		\
1124 		C(SYM_ADDR,		"sym-addr"),		\
1125 		C(VERBOSE,		"verbose"),		\
1126 		C(RAW,			"raw"),			\
1127 		C(HEX,			"hex"),			\
1128 		C(BIN,			"bin"),			\
1129 		C(BLOCK,		"block"),		\
1130 		C(PRINTK,		"trace_printk"),	\
1131 		C(ANNOTATE,		"annotate"),		\
1132 		C(USERSTACKTRACE,	"userstacktrace"),	\
1133 		C(SYM_USEROBJ,		"sym-userobj"),		\
1134 		C(PRINTK_MSGONLY,	"printk-msg-only"),	\
1135 		C(CONTEXT_INFO,		"context-info"),   /* Print pid/cpu/time */ \
1136 		C(LATENCY_FMT,		"latency-format"),	\
1137 		C(RECORD_CMD,		"record-cmd"),		\
1138 		C(RECORD_TGID,		"record-tgid"),		\
1139 		C(OVERWRITE,		"overwrite"),		\
1140 		C(STOP_ON_FREE,		"disable_on_free"),	\
1141 		C(IRQ_INFO,		"irq-info"),		\
1142 		C(MARKERS,		"markers"),		\
1143 		C(EVENT_FORK,		"event-fork"),		\
1144 		FUNCTION_FLAGS					\
1145 		FGRAPH_FLAGS					\
1146 		STACK_FLAGS					\
1147 		BRANCH_FLAGS
1148 
1149 /*
1150  * By defining C, we can make TRACE_FLAGS a list of bit names
1151  * that will define the bits for the flag masks.
1152  */
1153 #undef C
1154 #define C(a, b) TRACE_ITER_##a##_BIT
1155 
1156 enum trace_iterator_bits {
1157 	TRACE_FLAGS
1158 	/* Make sure we don't go more than we have bits for */
1159 	TRACE_ITER_LAST_BIT
1160 };
1161 
1162 /*
1163  * By redefining C, we can make TRACE_FLAGS a list of masks that
1164  * use the bits as defined above.
1165  */
1166 #undef C
1167 #define C(a, b) TRACE_ITER_##a = (1 << TRACE_ITER_##a##_BIT)
1168 
1169 enum trace_iterator_flags { TRACE_FLAGS };
1170 
1171 /*
1172  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
1173  * control the output of kernel symbols.
1174  */
1175 #define TRACE_ITER_SYM_MASK \
1176 	(TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
1177 
1178 extern struct tracer nop_trace;
1179 
1180 #ifdef CONFIG_BRANCH_TRACER
1181 extern int enable_branch_tracing(struct trace_array *tr);
1182 extern void disable_branch_tracing(void);
1183 static inline int trace_branch_enable(struct trace_array *tr)
1184 {
1185 	if (tr->trace_flags & TRACE_ITER_BRANCH)
1186 		return enable_branch_tracing(tr);
1187 	return 0;
1188 }
1189 static inline void trace_branch_disable(void)
1190 {
1191 	/* due to races, always disable */
1192 	disable_branch_tracing();
1193 }
1194 #else
1195 static inline int trace_branch_enable(struct trace_array *tr)
1196 {
1197 	return 0;
1198 }
1199 static inline void trace_branch_disable(void)
1200 {
1201 }
1202 #endif /* CONFIG_BRANCH_TRACER */
1203 
1204 /* set ring buffers to default size if not already done so */
1205 int tracing_update_buffers(void);
1206 
1207 struct ftrace_event_field {
1208 	struct list_head	link;
1209 	const char		*name;
1210 	const char		*type;
1211 	int			filter_type;
1212 	int			offset;
1213 	int			size;
1214 	int			is_signed;
1215 };
1216 
1217 struct prog_entry;
1218 
1219 struct event_filter {
1220 	struct prog_entry __rcu	*prog;
1221 	char			*filter_string;
1222 };
1223 
1224 struct event_subsystem {
1225 	struct list_head	list;
1226 	const char		*name;
1227 	struct event_filter	*filter;
1228 	int			ref_count;
1229 };
1230 
1231 struct trace_subsystem_dir {
1232 	struct list_head		list;
1233 	struct event_subsystem		*subsystem;
1234 	struct trace_array		*tr;
1235 	struct dentry			*entry;
1236 	int				ref_count;
1237 	int				nr_events;
1238 };
1239 
1240 extern int call_filter_check_discard(struct trace_event_call *call, void *rec,
1241 				     struct ring_buffer *buffer,
1242 				     struct ring_buffer_event *event);
1243 
1244 void trace_buffer_unlock_commit_regs(struct trace_array *tr,
1245 				     struct ring_buffer *buffer,
1246 				     struct ring_buffer_event *event,
1247 				     unsigned long flags, int pc,
1248 				     struct pt_regs *regs);
1249 
1250 static inline void trace_buffer_unlock_commit(struct trace_array *tr,
1251 					      struct ring_buffer *buffer,
1252 					      struct ring_buffer_event *event,
1253 					      unsigned long flags, int pc)
1254 {
1255 	trace_buffer_unlock_commit_regs(tr, buffer, event, flags, pc, NULL);
1256 }
1257 
1258 DECLARE_PER_CPU(struct ring_buffer_event *, trace_buffered_event);
1259 DECLARE_PER_CPU(int, trace_buffered_event_cnt);
1260 void trace_buffered_event_disable(void);
1261 void trace_buffered_event_enable(void);
1262 
1263 static inline void
1264 __trace_event_discard_commit(struct ring_buffer *buffer,
1265 			     struct ring_buffer_event *event)
1266 {
1267 	if (this_cpu_read(trace_buffered_event) == event) {
1268 		/* Simply release the temp buffer */
1269 		this_cpu_dec(trace_buffered_event_cnt);
1270 		return;
1271 	}
1272 	ring_buffer_discard_commit(buffer, event);
1273 }
1274 
1275 /*
1276  * Helper function for event_trigger_unlock_commit{_regs}().
1277  * If there are event triggers attached to this event that requires
1278  * filtering against its fields, then they wil be called as the
1279  * entry already holds the field information of the current event.
1280  *
1281  * It also checks if the event should be discarded or not.
1282  * It is to be discarded if the event is soft disabled and the
1283  * event was only recorded to process triggers, or if the event
1284  * filter is active and this event did not match the filters.
1285  *
1286  * Returns true if the event is discarded, false otherwise.
1287  */
1288 static inline bool
1289 __event_trigger_test_discard(struct trace_event_file *file,
1290 			     struct ring_buffer *buffer,
1291 			     struct ring_buffer_event *event,
1292 			     void *entry,
1293 			     enum event_trigger_type *tt)
1294 {
1295 	unsigned long eflags = file->flags;
1296 
1297 	if (eflags & EVENT_FILE_FL_TRIGGER_COND)
1298 		*tt = event_triggers_call(file, entry, event);
1299 
1300 	if (test_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags) ||
1301 	    (unlikely(file->flags & EVENT_FILE_FL_FILTERED) &&
1302 	     !filter_match_preds(file->filter, entry))) {
1303 		__trace_event_discard_commit(buffer, event);
1304 		return true;
1305 	}
1306 
1307 	return false;
1308 }
1309 
1310 /**
1311  * event_trigger_unlock_commit - handle triggers and finish event commit
1312  * @file: The file pointer assoctiated to the event
1313  * @buffer: The ring buffer that the event is being written to
1314  * @event: The event meta data in the ring buffer
1315  * @entry: The event itself
1316  * @irq_flags: The state of the interrupts at the start of the event
1317  * @pc: The state of the preempt count at the start of the event.
1318  *
1319  * This is a helper function to handle triggers that require data
1320  * from the event itself. It also tests the event against filters and
1321  * if the event is soft disabled and should be discarded.
1322  */
1323 static inline void
1324 event_trigger_unlock_commit(struct trace_event_file *file,
1325 			    struct ring_buffer *buffer,
1326 			    struct ring_buffer_event *event,
1327 			    void *entry, unsigned long irq_flags, int pc)
1328 {
1329 	enum event_trigger_type tt = ETT_NONE;
1330 
1331 	if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1332 		trace_buffer_unlock_commit(file->tr, buffer, event, irq_flags, pc);
1333 
1334 	if (tt)
1335 		event_triggers_post_call(file, tt);
1336 }
1337 
1338 /**
1339  * event_trigger_unlock_commit_regs - handle triggers and finish event commit
1340  * @file: The file pointer assoctiated to the event
1341  * @buffer: The ring buffer that the event is being written to
1342  * @event: The event meta data in the ring buffer
1343  * @entry: The event itself
1344  * @irq_flags: The state of the interrupts at the start of the event
1345  * @pc: The state of the preempt count at the start of the event.
1346  *
1347  * This is a helper function to handle triggers that require data
1348  * from the event itself. It also tests the event against filters and
1349  * if the event is soft disabled and should be discarded.
1350  *
1351  * Same as event_trigger_unlock_commit() but calls
1352  * trace_buffer_unlock_commit_regs() instead of trace_buffer_unlock_commit().
1353  */
1354 static inline void
1355 event_trigger_unlock_commit_regs(struct trace_event_file *file,
1356 				 struct ring_buffer *buffer,
1357 				 struct ring_buffer_event *event,
1358 				 void *entry, unsigned long irq_flags, int pc,
1359 				 struct pt_regs *regs)
1360 {
1361 	enum event_trigger_type tt = ETT_NONE;
1362 
1363 	if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1364 		trace_buffer_unlock_commit_regs(file->tr, buffer, event,
1365 						irq_flags, pc, regs);
1366 
1367 	if (tt)
1368 		event_triggers_post_call(file, tt);
1369 }
1370 
1371 #define FILTER_PRED_INVALID	((unsigned short)-1)
1372 #define FILTER_PRED_IS_RIGHT	(1 << 15)
1373 #define FILTER_PRED_FOLD	(1 << 15)
1374 
1375 /*
1376  * The max preds is the size of unsigned short with
1377  * two flags at the MSBs. One bit is used for both the IS_RIGHT
1378  * and FOLD flags. The other is reserved.
1379  *
1380  * 2^14 preds is way more than enough.
1381  */
1382 #define MAX_FILTER_PRED		16384
1383 
1384 struct filter_pred;
1385 struct regex;
1386 
1387 typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event);
1388 
1389 typedef int (*regex_match_func)(char *str, struct regex *r, int len);
1390 
1391 enum regex_type {
1392 	MATCH_FULL = 0,
1393 	MATCH_FRONT_ONLY,
1394 	MATCH_MIDDLE_ONLY,
1395 	MATCH_END_ONLY,
1396 	MATCH_GLOB,
1397 };
1398 
1399 struct regex {
1400 	char			pattern[MAX_FILTER_STR_VAL];
1401 	int			len;
1402 	int			field_len;
1403 	regex_match_func	match;
1404 };
1405 
1406 struct filter_pred {
1407 	filter_pred_fn_t 	fn;
1408 	u64 			val;
1409 	struct regex		regex;
1410 	unsigned short		*ops;
1411 	struct ftrace_event_field *field;
1412 	int 			offset;
1413 	int			not;
1414 	int 			op;
1415 };
1416 
1417 static inline bool is_string_field(struct ftrace_event_field *field)
1418 {
1419 	return field->filter_type == FILTER_DYN_STRING ||
1420 	       field->filter_type == FILTER_STATIC_STRING ||
1421 	       field->filter_type == FILTER_PTR_STRING ||
1422 	       field->filter_type == FILTER_COMM;
1423 }
1424 
1425 static inline bool is_function_field(struct ftrace_event_field *field)
1426 {
1427 	return field->filter_type == FILTER_TRACE_FN;
1428 }
1429 
1430 extern enum regex_type
1431 filter_parse_regex(char *buff, int len, char **search, int *not);
1432 extern void print_event_filter(struct trace_event_file *file,
1433 			       struct trace_seq *s);
1434 extern int apply_event_filter(struct trace_event_file *file,
1435 			      char *filter_string);
1436 extern int apply_subsystem_event_filter(struct trace_subsystem_dir *dir,
1437 					char *filter_string);
1438 extern void print_subsystem_event_filter(struct event_subsystem *system,
1439 					 struct trace_seq *s);
1440 extern int filter_assign_type(const char *type);
1441 extern int create_event_filter(struct trace_event_call *call,
1442 			       char *filter_str, bool set_str,
1443 			       struct event_filter **filterp);
1444 extern void free_event_filter(struct event_filter *filter);
1445 
1446 struct ftrace_event_field *
1447 trace_find_event_field(struct trace_event_call *call, char *name);
1448 
1449 extern void trace_event_enable_cmd_record(bool enable);
1450 extern void trace_event_enable_tgid_record(bool enable);
1451 
1452 extern int event_trace_init(void);
1453 extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
1454 extern int event_trace_del_tracer(struct trace_array *tr);
1455 
1456 extern struct trace_event_file *__find_event_file(struct trace_array *tr,
1457 						  const char *system,
1458 						  const char *event);
1459 extern struct trace_event_file *find_event_file(struct trace_array *tr,
1460 						const char *system,
1461 						const char *event);
1462 
1463 static inline void *event_file_data(struct file *filp)
1464 {
1465 	return READ_ONCE(file_inode(filp)->i_private);
1466 }
1467 
1468 extern struct mutex event_mutex;
1469 extern struct list_head ftrace_events;
1470 
1471 extern const struct file_operations event_trigger_fops;
1472 extern const struct file_operations event_hist_fops;
1473 
1474 #ifdef CONFIG_HIST_TRIGGERS
1475 extern int register_trigger_hist_cmd(void);
1476 extern int register_trigger_hist_enable_disable_cmds(void);
1477 #else
1478 static inline int register_trigger_hist_cmd(void) { return 0; }
1479 static inline int register_trigger_hist_enable_disable_cmds(void) { return 0; }
1480 #endif
1481 
1482 extern int register_trigger_cmds(void);
1483 extern void clear_event_triggers(struct trace_array *tr);
1484 
1485 struct event_trigger_data {
1486 	unsigned long			count;
1487 	int				ref;
1488 	struct event_trigger_ops	*ops;
1489 	struct event_command		*cmd_ops;
1490 	struct event_filter __rcu	*filter;
1491 	char				*filter_str;
1492 	void				*private_data;
1493 	bool				paused;
1494 	bool				paused_tmp;
1495 	struct list_head		list;
1496 	char				*name;
1497 	struct list_head		named_list;
1498 	struct event_trigger_data	*named_data;
1499 };
1500 
1501 /* Avoid typos */
1502 #define ENABLE_EVENT_STR	"enable_event"
1503 #define DISABLE_EVENT_STR	"disable_event"
1504 #define ENABLE_HIST_STR		"enable_hist"
1505 #define DISABLE_HIST_STR	"disable_hist"
1506 
1507 struct enable_trigger_data {
1508 	struct trace_event_file		*file;
1509 	bool				enable;
1510 	bool				hist;
1511 };
1512 
1513 extern int event_enable_trigger_print(struct seq_file *m,
1514 				      struct event_trigger_ops *ops,
1515 				      struct event_trigger_data *data);
1516 extern void event_enable_trigger_free(struct event_trigger_ops *ops,
1517 				      struct event_trigger_data *data);
1518 extern int event_enable_trigger_func(struct event_command *cmd_ops,
1519 				     struct trace_event_file *file,
1520 				     char *glob, char *cmd, char *param);
1521 extern int event_enable_register_trigger(char *glob,
1522 					 struct event_trigger_ops *ops,
1523 					 struct event_trigger_data *data,
1524 					 struct trace_event_file *file);
1525 extern void event_enable_unregister_trigger(char *glob,
1526 					    struct event_trigger_ops *ops,
1527 					    struct event_trigger_data *test,
1528 					    struct trace_event_file *file);
1529 extern void trigger_data_free(struct event_trigger_data *data);
1530 extern int event_trigger_init(struct event_trigger_ops *ops,
1531 			      struct event_trigger_data *data);
1532 extern int trace_event_trigger_enable_disable(struct trace_event_file *file,
1533 					      int trigger_enable);
1534 extern void update_cond_flag(struct trace_event_file *file);
1535 extern int set_trigger_filter(char *filter_str,
1536 			      struct event_trigger_data *trigger_data,
1537 			      struct trace_event_file *file);
1538 extern struct event_trigger_data *find_named_trigger(const char *name);
1539 extern bool is_named_trigger(struct event_trigger_data *test);
1540 extern int save_named_trigger(const char *name,
1541 			      struct event_trigger_data *data);
1542 extern void del_named_trigger(struct event_trigger_data *data);
1543 extern void pause_named_trigger(struct event_trigger_data *data);
1544 extern void unpause_named_trigger(struct event_trigger_data *data);
1545 extern void set_named_trigger_data(struct event_trigger_data *data,
1546 				   struct event_trigger_data *named_data);
1547 extern struct event_trigger_data *
1548 get_named_trigger_data(struct event_trigger_data *data);
1549 extern int register_event_command(struct event_command *cmd);
1550 extern int unregister_event_command(struct event_command *cmd);
1551 extern int register_trigger_hist_enable_disable_cmds(void);
1552 
1553 /**
1554  * struct event_trigger_ops - callbacks for trace event triggers
1555  *
1556  * The methods in this structure provide per-event trigger hooks for
1557  * various trigger operations.
1558  *
1559  * All the methods below, except for @init() and @free(), must be
1560  * implemented.
1561  *
1562  * @func: The trigger 'probe' function called when the triggering
1563  *	event occurs.  The data passed into this callback is the data
1564  *	that was supplied to the event_command @reg() function that
1565  *	registered the trigger (see struct event_command) along with
1566  *	the trace record, rec.
1567  *
1568  * @init: An optional initialization function called for the trigger
1569  *	when the trigger is registered (via the event_command reg()
1570  *	function).  This can be used to perform per-trigger
1571  *	initialization such as incrementing a per-trigger reference
1572  *	count, for instance.  This is usually implemented by the
1573  *	generic utility function @event_trigger_init() (see
1574  *	trace_event_triggers.c).
1575  *
1576  * @free: An optional de-initialization function called for the
1577  *	trigger when the trigger is unregistered (via the
1578  *	event_command @reg() function).  This can be used to perform
1579  *	per-trigger de-initialization such as decrementing a
1580  *	per-trigger reference count and freeing corresponding trigger
1581  *	data, for instance.  This is usually implemented by the
1582  *	generic utility function @event_trigger_free() (see
1583  *	trace_event_triggers.c).
1584  *
1585  * @print: The callback function invoked to have the trigger print
1586  *	itself.  This is usually implemented by a wrapper function
1587  *	that calls the generic utility function @event_trigger_print()
1588  *	(see trace_event_triggers.c).
1589  */
1590 struct event_trigger_ops {
1591 	void			(*func)(struct event_trigger_data *data,
1592 					void *rec,
1593 					struct ring_buffer_event *rbe);
1594 	int			(*init)(struct event_trigger_ops *ops,
1595 					struct event_trigger_data *data);
1596 	void			(*free)(struct event_trigger_ops *ops,
1597 					struct event_trigger_data *data);
1598 	int			(*print)(struct seq_file *m,
1599 					 struct event_trigger_ops *ops,
1600 					 struct event_trigger_data *data);
1601 };
1602 
1603 /**
1604  * struct event_command - callbacks and data members for event commands
1605  *
1606  * Event commands are invoked by users by writing the command name
1607  * into the 'trigger' file associated with a trace event.  The
1608  * parameters associated with a specific invocation of an event
1609  * command are used to create an event trigger instance, which is
1610  * added to the list of trigger instances associated with that trace
1611  * event.  When the event is hit, the set of triggers associated with
1612  * that event is invoked.
1613  *
1614  * The data members in this structure provide per-event command data
1615  * for various event commands.
1616  *
1617  * All the data members below, except for @post_trigger, must be set
1618  * for each event command.
1619  *
1620  * @name: The unique name that identifies the event command.  This is
1621  *	the name used when setting triggers via trigger files.
1622  *
1623  * @trigger_type: A unique id that identifies the event command
1624  *	'type'.  This value has two purposes, the first to ensure that
1625  *	only one trigger of the same type can be set at a given time
1626  *	for a particular event e.g. it doesn't make sense to have both
1627  *	a traceon and traceoff trigger attached to a single event at
1628  *	the same time, so traceon and traceoff have the same type
1629  *	though they have different names.  The @trigger_type value is
1630  *	also used as a bit value for deferring the actual trigger
1631  *	action until after the current event is finished.  Some
1632  *	commands need to do this if they themselves log to the trace
1633  *	buffer (see the @post_trigger() member below).  @trigger_type
1634  *	values are defined by adding new values to the trigger_type
1635  *	enum in include/linux/trace_events.h.
1636  *
1637  * @flags: See the enum event_command_flags below.
1638  *
1639  * All the methods below, except for @set_filter() and @unreg_all(),
1640  * must be implemented.
1641  *
1642  * @func: The callback function responsible for parsing and
1643  *	registering the trigger written to the 'trigger' file by the
1644  *	user.  It allocates the trigger instance and registers it with
1645  *	the appropriate trace event.  It makes use of the other
1646  *	event_command callback functions to orchestrate this, and is
1647  *	usually implemented by the generic utility function
1648  *	@event_trigger_callback() (see trace_event_triggers.c).
1649  *
1650  * @reg: Adds the trigger to the list of triggers associated with the
1651  *	event, and enables the event trigger itself, after
1652  *	initializing it (via the event_trigger_ops @init() function).
1653  *	This is also where commands can use the @trigger_type value to
1654  *	make the decision as to whether or not multiple instances of
1655  *	the trigger should be allowed.  This is usually implemented by
1656  *	the generic utility function @register_trigger() (see
1657  *	trace_event_triggers.c).
1658  *
1659  * @unreg: Removes the trigger from the list of triggers associated
1660  *	with the event, and disables the event trigger itself, after
1661  *	initializing it (via the event_trigger_ops @free() function).
1662  *	This is usually implemented by the generic utility function
1663  *	@unregister_trigger() (see trace_event_triggers.c).
1664  *
1665  * @unreg_all: An optional function called to remove all the triggers
1666  *	from the list of triggers associated with the event.  Called
1667  *	when a trigger file is opened in truncate mode.
1668  *
1669  * @set_filter: An optional function called to parse and set a filter
1670  *	for the trigger.  If no @set_filter() method is set for the
1671  *	event command, filters set by the user for the command will be
1672  *	ignored.  This is usually implemented by the generic utility
1673  *	function @set_trigger_filter() (see trace_event_triggers.c).
1674  *
1675  * @get_trigger_ops: The callback function invoked to retrieve the
1676  *	event_trigger_ops implementation associated with the command.
1677  */
1678 struct event_command {
1679 	struct list_head	list;
1680 	char			*name;
1681 	enum event_trigger_type	trigger_type;
1682 	int			flags;
1683 	int			(*func)(struct event_command *cmd_ops,
1684 					struct trace_event_file *file,
1685 					char *glob, char *cmd, char *params);
1686 	int			(*reg)(char *glob,
1687 				       struct event_trigger_ops *ops,
1688 				       struct event_trigger_data *data,
1689 				       struct trace_event_file *file);
1690 	void			(*unreg)(char *glob,
1691 					 struct event_trigger_ops *ops,
1692 					 struct event_trigger_data *data,
1693 					 struct trace_event_file *file);
1694 	void			(*unreg_all)(struct trace_event_file *file);
1695 	int			(*set_filter)(char *filter_str,
1696 					      struct event_trigger_data *data,
1697 					      struct trace_event_file *file);
1698 	struct event_trigger_ops *(*get_trigger_ops)(char *cmd, char *param);
1699 };
1700 
1701 /**
1702  * enum event_command_flags - flags for struct event_command
1703  *
1704  * @POST_TRIGGER: A flag that says whether or not this command needs
1705  *	to have its action delayed until after the current event has
1706  *	been closed.  Some triggers need to avoid being invoked while
1707  *	an event is currently in the process of being logged, since
1708  *	the trigger may itself log data into the trace buffer.  Thus
1709  *	we make sure the current event is committed before invoking
1710  *	those triggers.  To do that, the trigger invocation is split
1711  *	in two - the first part checks the filter using the current
1712  *	trace record; if a command has the @post_trigger flag set, it
1713  *	sets a bit for itself in the return value, otherwise it
1714  *	directly invokes the trigger.  Once all commands have been
1715  *	either invoked or set their return flag, the current record is
1716  *	either committed or discarded.  At that point, if any commands
1717  *	have deferred their triggers, those commands are finally
1718  *	invoked following the close of the current event.  In other
1719  *	words, if the event_trigger_ops @func() probe implementation
1720  *	itself logs to the trace buffer, this flag should be set,
1721  *	otherwise it can be left unspecified.
1722  *
1723  * @NEEDS_REC: A flag that says whether or not this command needs
1724  *	access to the trace record in order to perform its function,
1725  *	regardless of whether or not it has a filter associated with
1726  *	it (filters make a trigger require access to the trace record
1727  *	but are not always present).
1728  */
1729 enum event_command_flags {
1730 	EVENT_CMD_FL_POST_TRIGGER	= 1,
1731 	EVENT_CMD_FL_NEEDS_REC		= 2,
1732 };
1733 
1734 static inline bool event_command_post_trigger(struct event_command *cmd_ops)
1735 {
1736 	return cmd_ops->flags & EVENT_CMD_FL_POST_TRIGGER;
1737 }
1738 
1739 static inline bool event_command_needs_rec(struct event_command *cmd_ops)
1740 {
1741 	return cmd_ops->flags & EVENT_CMD_FL_NEEDS_REC;
1742 }
1743 
1744 extern int trace_event_enable_disable(struct trace_event_file *file,
1745 				      int enable, int soft_disable);
1746 extern int tracing_alloc_snapshot(void);
1747 
1748 extern const char *__start___trace_bprintk_fmt[];
1749 extern const char *__stop___trace_bprintk_fmt[];
1750 
1751 extern const char *__start___tracepoint_str[];
1752 extern const char *__stop___tracepoint_str[];
1753 
1754 void trace_printk_control(bool enabled);
1755 void trace_printk_init_buffers(void);
1756 void trace_printk_start_comm(void);
1757 int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set);
1758 int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled);
1759 
1760 #define MAX_EVENT_NAME_LEN	64
1761 
1762 extern int trace_run_command(const char *buf, int (*createfn)(int, char**));
1763 extern ssize_t trace_parse_run_command(struct file *file,
1764 		const char __user *buffer, size_t count, loff_t *ppos,
1765 		int (*createfn)(int, char**));
1766 
1767 /*
1768  * Normal trace_printk() and friends allocates special buffers
1769  * to do the manipulation, as well as saves the print formats
1770  * into sections to display. But the trace infrastructure wants
1771  * to use these without the added overhead at the price of being
1772  * a bit slower (used mainly for warnings, where we don't care
1773  * about performance). The internal_trace_puts() is for such
1774  * a purpose.
1775  */
1776 #define internal_trace_puts(str) __trace_puts(_THIS_IP_, str, strlen(str))
1777 
1778 #undef FTRACE_ENTRY
1779 #define FTRACE_ENTRY(call, struct_name, id, tstruct, print, filter)	\
1780 	extern struct trace_event_call					\
1781 	__aligned(4) event_##call;
1782 #undef FTRACE_ENTRY_DUP
1783 #define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print, filter)	\
1784 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print), \
1785 		     filter)
1786 #undef FTRACE_ENTRY_PACKED
1787 #define FTRACE_ENTRY_PACKED(call, struct_name, id, tstruct, print, filter) \
1788 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print), \
1789 		     filter)
1790 
1791 #include "trace_entries.h"
1792 
1793 #if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_FUNCTION_TRACER)
1794 int perf_ftrace_event_register(struct trace_event_call *call,
1795 			       enum trace_reg type, void *data);
1796 #else
1797 #define perf_ftrace_event_register NULL
1798 #endif
1799 
1800 #ifdef CONFIG_FTRACE_SYSCALLS
1801 void init_ftrace_syscalls(void);
1802 const char *get_syscall_name(int syscall);
1803 #else
1804 static inline void init_ftrace_syscalls(void) { }
1805 static inline const char *get_syscall_name(int syscall)
1806 {
1807 	return NULL;
1808 }
1809 #endif
1810 
1811 #ifdef CONFIG_EVENT_TRACING
1812 void trace_event_init(void);
1813 void trace_event_eval_update(struct trace_eval_map **map, int len);
1814 #else
1815 static inline void __init trace_event_init(void) { }
1816 static inline void trace_event_eval_update(struct trace_eval_map **map, int len) { }
1817 #endif
1818 
1819 #ifdef CONFIG_TRACER_SNAPSHOT
1820 void tracing_snapshot_instance(struct trace_array *tr);
1821 int tracing_alloc_snapshot_instance(struct trace_array *tr);
1822 #else
1823 static inline void tracing_snapshot_instance(struct trace_array *tr) { }
1824 static inline int tracing_alloc_snapshot_instance(struct trace_array *tr)
1825 {
1826 	return 0;
1827 }
1828 #endif
1829 
1830 #ifdef CONFIG_PREEMPT_TRACER
1831 void tracer_preempt_on(unsigned long a0, unsigned long a1);
1832 void tracer_preempt_off(unsigned long a0, unsigned long a1);
1833 #else
1834 static inline void tracer_preempt_on(unsigned long a0, unsigned long a1) { }
1835 static inline void tracer_preempt_off(unsigned long a0, unsigned long a1) { }
1836 #endif
1837 #ifdef CONFIG_IRQSOFF_TRACER
1838 void tracer_hardirqs_on(unsigned long a0, unsigned long a1);
1839 void tracer_hardirqs_off(unsigned long a0, unsigned long a1);
1840 #else
1841 static inline void tracer_hardirqs_on(unsigned long a0, unsigned long a1) { }
1842 static inline void tracer_hardirqs_off(unsigned long a0, unsigned long a1) { }
1843 #endif
1844 
1845 extern struct trace_iterator *tracepoint_print_iter;
1846 
1847 #endif /* _LINUX_KERNEL_TRACE_H */
1848