xref: /linux/kernel/trace/trace.h (revision a8b70ccf10e38775785d9cb12ead916474549f99)
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 	cpumask_var_t		tracing_cpumask; /* only trace on set CPUs */
263 	int			ref;
264 #ifdef CONFIG_FUNCTION_TRACER
265 	struct ftrace_ops	*ops;
266 	struct trace_pid_list	__rcu *function_pids;
267 #ifdef CONFIG_DYNAMIC_FTRACE
268 	/* All of these are protected by the ftrace_lock */
269 	struct list_head	func_probes;
270 	struct list_head	mod_trace;
271 	struct list_head	mod_notrace;
272 #endif
273 	/* function tracing enabled */
274 	int			function_enabled;
275 #endif
276 	int			time_stamp_abs_ref;
277 	struct list_head	hist_vars;
278 };
279 
280 enum {
281 	TRACE_ARRAY_FL_GLOBAL	= (1 << 0)
282 };
283 
284 extern struct list_head ftrace_trace_arrays;
285 
286 extern struct mutex trace_types_lock;
287 
288 extern int trace_array_get(struct trace_array *tr);
289 extern void trace_array_put(struct trace_array *tr);
290 
291 extern int tracing_set_time_stamp_abs(struct trace_array *tr, bool abs);
292 extern int tracing_set_clock(struct trace_array *tr, const char *clockstr);
293 
294 extern bool trace_clock_in_ns(struct trace_array *tr);
295 
296 /*
297  * The global tracer (top) should be the first trace array added,
298  * but we check the flag anyway.
299  */
300 static inline struct trace_array *top_trace_array(void)
301 {
302 	struct trace_array *tr;
303 
304 	if (list_empty(&ftrace_trace_arrays))
305 		return NULL;
306 
307 	tr = list_entry(ftrace_trace_arrays.prev,
308 			typeof(*tr), list);
309 	WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
310 	return tr;
311 }
312 
313 #define FTRACE_CMP_TYPE(var, type) \
314 	__builtin_types_compatible_p(typeof(var), type *)
315 
316 #undef IF_ASSIGN
317 #define IF_ASSIGN(var, entry, etype, id)		\
318 	if (FTRACE_CMP_TYPE(var, etype)) {		\
319 		var = (typeof(var))(entry);		\
320 		WARN_ON(id && (entry)->type != id);	\
321 		break;					\
322 	}
323 
324 /* Will cause compile errors if type is not found. */
325 extern void __ftrace_bad_type(void);
326 
327 /*
328  * The trace_assign_type is a verifier that the entry type is
329  * the same as the type being assigned. To add new types simply
330  * add a line with the following format:
331  *
332  * IF_ASSIGN(var, ent, type, id);
333  *
334  *  Where "type" is the trace type that includes the trace_entry
335  *  as the "ent" item. And "id" is the trace identifier that is
336  *  used in the trace_type enum.
337  *
338  *  If the type can have more than one id, then use zero.
339  */
340 #define trace_assign_type(var, ent)					\
341 	do {								\
342 		IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);	\
343 		IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);	\
344 		IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);	\
345 		IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
346 		IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);	\
347 		IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT);	\
348 		IF_ASSIGN(var, ent, struct bputs_entry, TRACE_BPUTS);	\
349 		IF_ASSIGN(var, ent, struct hwlat_entry, TRACE_HWLAT);	\
350 		IF_ASSIGN(var, ent, struct raw_data_entry, TRACE_RAW_DATA);\
351 		IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,		\
352 			  TRACE_MMIO_RW);				\
353 		IF_ASSIGN(var, ent, struct trace_mmiotrace_map,		\
354 			  TRACE_MMIO_MAP);				\
355 		IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
356 		IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,	\
357 			  TRACE_GRAPH_ENT);		\
358 		IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,	\
359 			  TRACE_GRAPH_RET);		\
360 		__ftrace_bad_type();					\
361 	} while (0)
362 
363 /*
364  * An option specific to a tracer. This is a boolean value.
365  * The bit is the bit index that sets its value on the
366  * flags value in struct tracer_flags.
367  */
368 struct tracer_opt {
369 	const char	*name; /* Will appear on the trace_options file */
370 	u32		bit; /* Mask assigned in val field in tracer_flags */
371 };
372 
373 /*
374  * The set of specific options for a tracer. Your tracer
375  * have to set the initial value of the flags val.
376  */
377 struct tracer_flags {
378 	u32			val;
379 	struct tracer_opt	*opts;
380 	struct tracer		*trace;
381 };
382 
383 /* Makes more easy to define a tracer opt */
384 #define TRACER_OPT(s, b)	.name = #s, .bit = b
385 
386 
387 struct trace_option_dentry {
388 	struct tracer_opt		*opt;
389 	struct tracer_flags		*flags;
390 	struct trace_array		*tr;
391 	struct dentry			*entry;
392 };
393 
394 /**
395  * struct tracer - a specific tracer and its callbacks to interact with tracefs
396  * @name: the name chosen to select it on the available_tracers file
397  * @init: called when one switches to this tracer (echo name > current_tracer)
398  * @reset: called when one switches to another tracer
399  * @start: called when tracing is unpaused (echo 1 > tracing_on)
400  * @stop: called when tracing is paused (echo 0 > tracing_on)
401  * @update_thresh: called when tracing_thresh is updated
402  * @open: called when the trace file is opened
403  * @pipe_open: called when the trace_pipe file is opened
404  * @close: called when the trace file is released
405  * @pipe_close: called when the trace_pipe file is released
406  * @read: override the default read callback on trace_pipe
407  * @splice_read: override the default splice_read callback on trace_pipe
408  * @selftest: selftest to run on boot (see trace_selftest.c)
409  * @print_headers: override the first lines that describe your columns
410  * @print_line: callback that prints a trace
411  * @set_flag: signals one of your private flags changed (trace_options file)
412  * @flags: your private flags
413  */
414 struct tracer {
415 	const char		*name;
416 	int			(*init)(struct trace_array *tr);
417 	void			(*reset)(struct trace_array *tr);
418 	void			(*start)(struct trace_array *tr);
419 	void			(*stop)(struct trace_array *tr);
420 	int			(*update_thresh)(struct trace_array *tr);
421 	void			(*open)(struct trace_iterator *iter);
422 	void			(*pipe_open)(struct trace_iterator *iter);
423 	void			(*close)(struct trace_iterator *iter);
424 	void			(*pipe_close)(struct trace_iterator *iter);
425 	ssize_t			(*read)(struct trace_iterator *iter,
426 					struct file *filp, char __user *ubuf,
427 					size_t cnt, loff_t *ppos);
428 	ssize_t			(*splice_read)(struct trace_iterator *iter,
429 					       struct file *filp,
430 					       loff_t *ppos,
431 					       struct pipe_inode_info *pipe,
432 					       size_t len,
433 					       unsigned int flags);
434 #ifdef CONFIG_FTRACE_STARTUP_TEST
435 	int			(*selftest)(struct tracer *trace,
436 					    struct trace_array *tr);
437 #endif
438 	void			(*print_header)(struct seq_file *m);
439 	enum print_line_t	(*print_line)(struct trace_iterator *iter);
440 	/* If you handled the flag setting, return 0 */
441 	int			(*set_flag)(struct trace_array *tr,
442 					    u32 old_flags, u32 bit, int set);
443 	/* Return 0 if OK with change, else return non-zero */
444 	int			(*flag_changed)(struct trace_array *tr,
445 						u32 mask, int set);
446 	struct tracer		*next;
447 	struct tracer_flags	*flags;
448 	int			enabled;
449 	int			ref;
450 	bool			print_max;
451 	bool			allow_instances;
452 #ifdef CONFIG_TRACER_MAX_TRACE
453 	bool			use_max_tr;
454 #endif
455 	/* True if tracer cannot be enabled in kernel param */
456 	bool			noboot;
457 };
458 
459 
460 /* Only current can touch trace_recursion */
461 
462 /*
463  * For function tracing recursion:
464  *  The order of these bits are important.
465  *
466  *  When function tracing occurs, the following steps are made:
467  *   If arch does not support a ftrace feature:
468  *    call internal function (uses INTERNAL bits) which calls...
469  *   If callback is registered to the "global" list, the list
470  *    function is called and recursion checks the GLOBAL bits.
471  *    then this function calls...
472  *   The function callback, which can use the FTRACE bits to
473  *    check for recursion.
474  *
475  * Now if the arch does not suppport a feature, and it calls
476  * the global list function which calls the ftrace callback
477  * all three of these steps will do a recursion protection.
478  * There's no reason to do one if the previous caller already
479  * did. The recursion that we are protecting against will
480  * go through the same steps again.
481  *
482  * To prevent the multiple recursion checks, if a recursion
483  * bit is set that is higher than the MAX bit of the current
484  * check, then we know that the check was made by the previous
485  * caller, and we can skip the current check.
486  */
487 enum {
488 	TRACE_BUFFER_BIT,
489 	TRACE_BUFFER_NMI_BIT,
490 	TRACE_BUFFER_IRQ_BIT,
491 	TRACE_BUFFER_SIRQ_BIT,
492 
493 	/* Start of function recursion bits */
494 	TRACE_FTRACE_BIT,
495 	TRACE_FTRACE_NMI_BIT,
496 	TRACE_FTRACE_IRQ_BIT,
497 	TRACE_FTRACE_SIRQ_BIT,
498 
499 	/* INTERNAL_BITs must be greater than FTRACE_BITs */
500 	TRACE_INTERNAL_BIT,
501 	TRACE_INTERNAL_NMI_BIT,
502 	TRACE_INTERNAL_IRQ_BIT,
503 	TRACE_INTERNAL_SIRQ_BIT,
504 
505 	TRACE_BRANCH_BIT,
506 /*
507  * Abuse of the trace_recursion.
508  * As we need a way to maintain state if we are tracing the function
509  * graph in irq because we want to trace a particular function that
510  * was called in irq context but we have irq tracing off. Since this
511  * can only be modified by current, we can reuse trace_recursion.
512  */
513 	TRACE_IRQ_BIT,
514 };
515 
516 #define trace_recursion_set(bit)	do { (current)->trace_recursion |= (1<<(bit)); } while (0)
517 #define trace_recursion_clear(bit)	do { (current)->trace_recursion &= ~(1<<(bit)); } while (0)
518 #define trace_recursion_test(bit)	((current)->trace_recursion & (1<<(bit)))
519 
520 #define TRACE_CONTEXT_BITS	4
521 
522 #define TRACE_FTRACE_START	TRACE_FTRACE_BIT
523 #define TRACE_FTRACE_MAX	((1 << (TRACE_FTRACE_START + TRACE_CONTEXT_BITS)) - 1)
524 
525 #define TRACE_LIST_START	TRACE_INTERNAL_BIT
526 #define TRACE_LIST_MAX		((1 << (TRACE_LIST_START + TRACE_CONTEXT_BITS)) - 1)
527 
528 #define TRACE_CONTEXT_MASK	TRACE_LIST_MAX
529 
530 static __always_inline int trace_get_context_bit(void)
531 {
532 	int bit;
533 
534 	if (in_interrupt()) {
535 		if (in_nmi())
536 			bit = 0;
537 
538 		else if (in_irq())
539 			bit = 1;
540 		else
541 			bit = 2;
542 	} else
543 		bit = 3;
544 
545 	return bit;
546 }
547 
548 static __always_inline int trace_test_and_set_recursion(int start, int max)
549 {
550 	unsigned int val = current->trace_recursion;
551 	int bit;
552 
553 	/* A previous recursion check was made */
554 	if ((val & TRACE_CONTEXT_MASK) > max)
555 		return 0;
556 
557 	bit = trace_get_context_bit() + start;
558 	if (unlikely(val & (1 << bit)))
559 		return -1;
560 
561 	val |= 1 << bit;
562 	current->trace_recursion = val;
563 	barrier();
564 
565 	return bit;
566 }
567 
568 static __always_inline void trace_clear_recursion(int bit)
569 {
570 	unsigned int val = current->trace_recursion;
571 
572 	if (!bit)
573 		return;
574 
575 	bit = 1 << bit;
576 	val &= ~bit;
577 
578 	barrier();
579 	current->trace_recursion = val;
580 }
581 
582 static inline struct ring_buffer_iter *
583 trace_buffer_iter(struct trace_iterator *iter, int cpu)
584 {
585 	if (iter->buffer_iter && iter->buffer_iter[cpu])
586 		return iter->buffer_iter[cpu];
587 	return NULL;
588 }
589 
590 int tracer_init(struct tracer *t, struct trace_array *tr);
591 int tracing_is_enabled(void);
592 void tracing_reset(struct trace_buffer *buf, int cpu);
593 void tracing_reset_online_cpus(struct trace_buffer *buf);
594 void tracing_reset_current(int cpu);
595 void tracing_reset_all_online_cpus(void);
596 int tracing_open_generic(struct inode *inode, struct file *filp);
597 bool tracing_is_disabled(void);
598 int tracer_tracing_is_on(struct trace_array *tr);
599 void tracer_tracing_on(struct trace_array *tr);
600 void tracer_tracing_off(struct trace_array *tr);
601 struct dentry *trace_create_file(const char *name,
602 				 umode_t mode,
603 				 struct dentry *parent,
604 				 void *data,
605 				 const struct file_operations *fops);
606 
607 struct dentry *tracing_init_dentry(void);
608 
609 struct ring_buffer_event;
610 
611 struct ring_buffer_event *
612 trace_buffer_lock_reserve(struct ring_buffer *buffer,
613 			  int type,
614 			  unsigned long len,
615 			  unsigned long flags,
616 			  int pc);
617 
618 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
619 						struct trace_array_cpu *data);
620 
621 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
622 					  int *ent_cpu, u64 *ent_ts);
623 
624 void trace_buffer_unlock_commit_nostack(struct ring_buffer *buffer,
625 					struct ring_buffer_event *event);
626 
627 int trace_empty(struct trace_iterator *iter);
628 
629 void *trace_find_next_entry_inc(struct trace_iterator *iter);
630 
631 void trace_init_global_iter(struct trace_iterator *iter);
632 
633 void tracing_iter_reset(struct trace_iterator *iter, int cpu);
634 
635 void trace_function(struct trace_array *tr,
636 		    unsigned long ip,
637 		    unsigned long parent_ip,
638 		    unsigned long flags, int pc);
639 void trace_graph_function(struct trace_array *tr,
640 		    unsigned long ip,
641 		    unsigned long parent_ip,
642 		    unsigned long flags, int pc);
643 void trace_latency_header(struct seq_file *m);
644 void trace_default_header(struct seq_file *m);
645 void print_trace_header(struct seq_file *m, struct trace_iterator *iter);
646 int trace_empty(struct trace_iterator *iter);
647 
648 void trace_graph_return(struct ftrace_graph_ret *trace);
649 int trace_graph_entry(struct ftrace_graph_ent *trace);
650 void set_graph_array(struct trace_array *tr);
651 
652 void tracing_start_cmdline_record(void);
653 void tracing_stop_cmdline_record(void);
654 void tracing_start_tgid_record(void);
655 void tracing_stop_tgid_record(void);
656 
657 int register_tracer(struct tracer *type);
658 int is_tracing_stopped(void);
659 
660 loff_t tracing_lseek(struct file *file, loff_t offset, int whence);
661 
662 extern cpumask_var_t __read_mostly tracing_buffer_mask;
663 
664 #define for_each_tracing_cpu(cpu)	\
665 	for_each_cpu(cpu, tracing_buffer_mask)
666 
667 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
668 
669 extern unsigned long tracing_thresh;
670 
671 /* PID filtering */
672 
673 extern int pid_max;
674 
675 bool trace_find_filtered_pid(struct trace_pid_list *filtered_pids,
676 			     pid_t search_pid);
677 bool trace_ignore_this_task(struct trace_pid_list *filtered_pids,
678 			    struct task_struct *task);
679 void trace_filter_add_remove_task(struct trace_pid_list *pid_list,
680 				  struct task_struct *self,
681 				  struct task_struct *task);
682 void *trace_pid_next(struct trace_pid_list *pid_list, void *v, loff_t *pos);
683 void *trace_pid_start(struct trace_pid_list *pid_list, loff_t *pos);
684 int trace_pid_show(struct seq_file *m, void *v);
685 void trace_free_pid_list(struct trace_pid_list *pid_list);
686 int trace_pid_write(struct trace_pid_list *filtered_pids,
687 		    struct trace_pid_list **new_pid_list,
688 		    const char __user *ubuf, size_t cnt);
689 
690 #ifdef CONFIG_TRACER_MAX_TRACE
691 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
692 void update_max_tr_single(struct trace_array *tr,
693 			  struct task_struct *tsk, int cpu);
694 #endif /* CONFIG_TRACER_MAX_TRACE */
695 
696 #ifdef CONFIG_STACKTRACE
697 void ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags,
698 			    int pc);
699 
700 void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
701 		   int pc);
702 #else
703 static inline void ftrace_trace_userstack(struct ring_buffer *buffer,
704 					  unsigned long flags, int pc)
705 {
706 }
707 
708 static inline void __trace_stack(struct trace_array *tr, unsigned long flags,
709 				 int skip, int pc)
710 {
711 }
712 #endif /* CONFIG_STACKTRACE */
713 
714 extern u64 ftrace_now(int cpu);
715 
716 extern void trace_find_cmdline(int pid, char comm[]);
717 extern int trace_find_tgid(int pid);
718 extern void trace_event_follow_fork(struct trace_array *tr, bool enable);
719 
720 #ifdef CONFIG_DYNAMIC_FTRACE
721 extern unsigned long ftrace_update_tot_cnt;
722 void ftrace_init_trace_array(struct trace_array *tr);
723 #else
724 static inline void ftrace_init_trace_array(struct trace_array *tr) { }
725 #endif
726 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
727 extern int DYN_FTRACE_TEST_NAME(void);
728 #define DYN_FTRACE_TEST_NAME2 trace_selftest_dynamic_test_func2
729 extern int DYN_FTRACE_TEST_NAME2(void);
730 
731 extern bool ring_buffer_expanded;
732 extern bool tracing_selftest_disabled;
733 
734 #ifdef CONFIG_FTRACE_STARTUP_TEST
735 extern int trace_selftest_startup_function(struct tracer *trace,
736 					   struct trace_array *tr);
737 extern int trace_selftest_startup_function_graph(struct tracer *trace,
738 						 struct trace_array *tr);
739 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
740 					  struct trace_array *tr);
741 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
742 					     struct trace_array *tr);
743 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
744 						 struct trace_array *tr);
745 extern int trace_selftest_startup_wakeup(struct tracer *trace,
746 					 struct trace_array *tr);
747 extern int trace_selftest_startup_nop(struct tracer *trace,
748 					 struct trace_array *tr);
749 extern int trace_selftest_startup_branch(struct tracer *trace,
750 					 struct trace_array *tr);
751 /*
752  * Tracer data references selftest functions that only occur
753  * on boot up. These can be __init functions. Thus, when selftests
754  * are enabled, then the tracers need to reference __init functions.
755  */
756 #define __tracer_data		__refdata
757 #else
758 /* Tracers are seldom changed. Optimize when selftests are disabled. */
759 #define __tracer_data		__read_mostly
760 #endif /* CONFIG_FTRACE_STARTUP_TEST */
761 
762 extern void *head_page(struct trace_array_cpu *data);
763 extern unsigned long long ns2usecs(u64 nsec);
764 extern int
765 trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
766 extern int
767 trace_vprintk(unsigned long ip, const char *fmt, va_list args);
768 extern int
769 trace_array_vprintk(struct trace_array *tr,
770 		    unsigned long ip, const char *fmt, va_list args);
771 int trace_array_printk(struct trace_array *tr,
772 		       unsigned long ip, const char *fmt, ...);
773 int trace_array_printk_buf(struct ring_buffer *buffer,
774 			   unsigned long ip, const char *fmt, ...);
775 void trace_printk_seq(struct trace_seq *s);
776 enum print_line_t print_trace_line(struct trace_iterator *iter);
777 
778 extern char trace_find_mark(unsigned long long duration);
779 
780 struct ftrace_hash;
781 
782 struct ftrace_mod_load {
783 	struct list_head	list;
784 	char			*func;
785 	char			*module;
786 	int			 enable;
787 };
788 
789 enum {
790 	FTRACE_HASH_FL_MOD	= (1 << 0),
791 };
792 
793 struct ftrace_hash {
794 	unsigned long		size_bits;
795 	struct hlist_head	*buckets;
796 	unsigned long		count;
797 	unsigned long		flags;
798 	struct rcu_head		rcu;
799 };
800 
801 struct ftrace_func_entry *
802 ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip);
803 
804 static __always_inline bool ftrace_hash_empty(struct ftrace_hash *hash)
805 {
806 	return !hash || !(hash->count || (hash->flags & FTRACE_HASH_FL_MOD));
807 }
808 
809 /* Standard output formatting function used for function return traces */
810 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
811 
812 /* Flag options */
813 #define TRACE_GRAPH_PRINT_OVERRUN       0x1
814 #define TRACE_GRAPH_PRINT_CPU           0x2
815 #define TRACE_GRAPH_PRINT_OVERHEAD      0x4
816 #define TRACE_GRAPH_PRINT_PROC          0x8
817 #define TRACE_GRAPH_PRINT_DURATION      0x10
818 #define TRACE_GRAPH_PRINT_ABS_TIME      0x20
819 #define TRACE_GRAPH_PRINT_IRQS          0x40
820 #define TRACE_GRAPH_PRINT_TAIL          0x80
821 #define TRACE_GRAPH_SLEEP_TIME		0x100
822 #define TRACE_GRAPH_GRAPH_TIME		0x200
823 #define TRACE_GRAPH_PRINT_FILL_SHIFT	28
824 #define TRACE_GRAPH_PRINT_FILL_MASK	(0x3 << TRACE_GRAPH_PRINT_FILL_SHIFT)
825 
826 extern void ftrace_graph_sleep_time_control(bool enable);
827 extern void ftrace_graph_graph_time_control(bool enable);
828 
829 extern enum print_line_t
830 print_graph_function_flags(struct trace_iterator *iter, u32 flags);
831 extern void print_graph_headers_flags(struct seq_file *s, u32 flags);
832 extern void
833 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
834 extern void graph_trace_open(struct trace_iterator *iter);
835 extern void graph_trace_close(struct trace_iterator *iter);
836 extern int __trace_graph_entry(struct trace_array *tr,
837 			       struct ftrace_graph_ent *trace,
838 			       unsigned long flags, int pc);
839 extern void __trace_graph_return(struct trace_array *tr,
840 				 struct ftrace_graph_ret *trace,
841 				 unsigned long flags, int pc);
842 
843 #ifdef CONFIG_DYNAMIC_FTRACE
844 extern struct ftrace_hash *ftrace_graph_hash;
845 extern struct ftrace_hash *ftrace_graph_notrace_hash;
846 
847 static inline int ftrace_graph_addr(unsigned long addr)
848 {
849 	int ret = 0;
850 
851 	preempt_disable_notrace();
852 
853 	if (ftrace_hash_empty(ftrace_graph_hash)) {
854 		ret = 1;
855 		goto out;
856 	}
857 
858 	if (ftrace_lookup_ip(ftrace_graph_hash, addr)) {
859 		/*
860 		 * If no irqs are to be traced, but a set_graph_function
861 		 * is set, and called by an interrupt handler, we still
862 		 * want to trace it.
863 		 */
864 		if (in_irq())
865 			trace_recursion_set(TRACE_IRQ_BIT);
866 		else
867 			trace_recursion_clear(TRACE_IRQ_BIT);
868 		ret = 1;
869 	}
870 
871 out:
872 	preempt_enable_notrace();
873 	return ret;
874 }
875 
876 static inline int ftrace_graph_notrace_addr(unsigned long addr)
877 {
878 	int ret = 0;
879 
880 	preempt_disable_notrace();
881 
882 	if (ftrace_lookup_ip(ftrace_graph_notrace_hash, addr))
883 		ret = 1;
884 
885 	preempt_enable_notrace();
886 	return ret;
887 }
888 #else
889 static inline int ftrace_graph_addr(unsigned long addr)
890 {
891 	return 1;
892 }
893 
894 static inline int ftrace_graph_notrace_addr(unsigned long addr)
895 {
896 	return 0;
897 }
898 #endif /* CONFIG_DYNAMIC_FTRACE */
899 
900 extern unsigned int fgraph_max_depth;
901 
902 static inline bool ftrace_graph_ignore_func(struct ftrace_graph_ent *trace)
903 {
904 	/* trace it when it is-nested-in or is a function enabled. */
905 	return !(trace->depth || ftrace_graph_addr(trace->func)) ||
906 		(trace->depth < 0) ||
907 		(fgraph_max_depth && trace->depth >= fgraph_max_depth);
908 }
909 
910 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
911 static inline enum print_line_t
912 print_graph_function_flags(struct trace_iterator *iter, u32 flags)
913 {
914 	return TRACE_TYPE_UNHANDLED;
915 }
916 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
917 
918 extern struct list_head ftrace_pids;
919 
920 #ifdef CONFIG_FUNCTION_TRACER
921 struct ftrace_func_command {
922 	struct list_head	list;
923 	char			*name;
924 	int			(*func)(struct trace_array *tr,
925 					struct ftrace_hash *hash,
926 					char *func, char *cmd,
927 					char *params, int enable);
928 };
929 extern bool ftrace_filter_param __initdata;
930 static inline int ftrace_trace_task(struct trace_array *tr)
931 {
932 	return !this_cpu_read(tr->trace_buffer.data->ftrace_ignore_pid);
933 }
934 extern int ftrace_is_dead(void);
935 int ftrace_create_function_files(struct trace_array *tr,
936 				 struct dentry *parent);
937 void ftrace_destroy_function_files(struct trace_array *tr);
938 void ftrace_init_global_array_ops(struct trace_array *tr);
939 void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func);
940 void ftrace_reset_array_ops(struct trace_array *tr);
941 int using_ftrace_ops_list_func(void);
942 void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer);
943 void ftrace_init_tracefs_toplevel(struct trace_array *tr,
944 				  struct dentry *d_tracer);
945 void ftrace_clear_pids(struct trace_array *tr);
946 int init_function_trace(void);
947 void ftrace_pid_follow_fork(struct trace_array *tr, bool enable);
948 #else
949 static inline int ftrace_trace_task(struct trace_array *tr)
950 {
951 	return 1;
952 }
953 static inline int ftrace_is_dead(void) { return 0; }
954 static inline int
955 ftrace_create_function_files(struct trace_array *tr,
956 			     struct dentry *parent)
957 {
958 	return 0;
959 }
960 static inline void ftrace_destroy_function_files(struct trace_array *tr) { }
961 static inline __init void
962 ftrace_init_global_array_ops(struct trace_array *tr) { }
963 static inline void ftrace_reset_array_ops(struct trace_array *tr) { }
964 static inline void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d) { }
965 static inline void ftrace_init_tracefs_toplevel(struct trace_array *tr, struct dentry *d) { }
966 static inline void ftrace_clear_pids(struct trace_array *tr) { }
967 static inline int init_function_trace(void) { return 0; }
968 static inline void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) { }
969 /* ftace_func_t type is not defined, use macro instead of static inline */
970 #define ftrace_init_array_ops(tr, func) do { } while (0)
971 #endif /* CONFIG_FUNCTION_TRACER */
972 
973 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
974 
975 struct ftrace_probe_ops {
976 	void			(*func)(unsigned long ip,
977 					unsigned long parent_ip,
978 					struct trace_array *tr,
979 					struct ftrace_probe_ops *ops,
980 					void *data);
981 	int			(*init)(struct ftrace_probe_ops *ops,
982 					struct trace_array *tr,
983 					unsigned long ip, void *init_data,
984 					void **data);
985 	void			(*free)(struct ftrace_probe_ops *ops,
986 					struct trace_array *tr,
987 					unsigned long ip, void *data);
988 	int			(*print)(struct seq_file *m,
989 					 unsigned long ip,
990 					 struct ftrace_probe_ops *ops,
991 					 void *data);
992 };
993 
994 struct ftrace_func_mapper;
995 typedef int (*ftrace_mapper_func)(void *data);
996 
997 struct ftrace_func_mapper *allocate_ftrace_func_mapper(void);
998 void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
999 					   unsigned long ip);
1000 int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
1001 			       unsigned long ip, void *data);
1002 void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
1003 				   unsigned long ip);
1004 void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
1005 			     ftrace_mapper_func free_func);
1006 
1007 extern int
1008 register_ftrace_function_probe(char *glob, struct trace_array *tr,
1009 			       struct ftrace_probe_ops *ops, void *data);
1010 extern int
1011 unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
1012 				      struct ftrace_probe_ops *ops);
1013 extern void clear_ftrace_function_probes(struct trace_array *tr);
1014 
1015 int register_ftrace_command(struct ftrace_func_command *cmd);
1016 int unregister_ftrace_command(struct ftrace_func_command *cmd);
1017 
1018 void ftrace_create_filter_files(struct ftrace_ops *ops,
1019 				struct dentry *parent);
1020 void ftrace_destroy_filter_files(struct ftrace_ops *ops);
1021 #else
1022 struct ftrace_func_command;
1023 
1024 static inline __init int register_ftrace_command(struct ftrace_func_command *cmd)
1025 {
1026 	return -EINVAL;
1027 }
1028 static inline __init int unregister_ftrace_command(char *cmd_name)
1029 {
1030 	return -EINVAL;
1031 }
1032 static inline void clear_ftrace_function_probes(struct trace_array *tr)
1033 {
1034 }
1035 
1036 /*
1037  * The ops parameter passed in is usually undefined.
1038  * This must be a macro.
1039  */
1040 #define ftrace_create_filter_files(ops, parent) do { } while (0)
1041 #define ftrace_destroy_filter_files(ops) do { } while (0)
1042 #endif /* CONFIG_FUNCTION_TRACER && CONFIG_DYNAMIC_FTRACE */
1043 
1044 bool ftrace_event_is_function(struct trace_event_call *call);
1045 
1046 /*
1047  * struct trace_parser - servers for reading the user input separated by spaces
1048  * @cont: set if the input is not complete - no final space char was found
1049  * @buffer: holds the parsed user input
1050  * @idx: user input length
1051  * @size: buffer size
1052  */
1053 struct trace_parser {
1054 	bool		cont;
1055 	char		*buffer;
1056 	unsigned	idx;
1057 	unsigned	size;
1058 };
1059 
1060 static inline bool trace_parser_loaded(struct trace_parser *parser)
1061 {
1062 	return (parser->idx != 0);
1063 }
1064 
1065 static inline bool trace_parser_cont(struct trace_parser *parser)
1066 {
1067 	return parser->cont;
1068 }
1069 
1070 static inline void trace_parser_clear(struct trace_parser *parser)
1071 {
1072 	parser->cont = false;
1073 	parser->idx = 0;
1074 }
1075 
1076 extern int trace_parser_get_init(struct trace_parser *parser, int size);
1077 extern void trace_parser_put(struct trace_parser *parser);
1078 extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
1079 	size_t cnt, loff_t *ppos);
1080 
1081 /*
1082  * Only create function graph options if function graph is configured.
1083  */
1084 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1085 # define FGRAPH_FLAGS						\
1086 		C(DISPLAY_GRAPH,	"display-graph"),
1087 #else
1088 # define FGRAPH_FLAGS
1089 #endif
1090 
1091 #ifdef CONFIG_BRANCH_TRACER
1092 # define BRANCH_FLAGS					\
1093 		C(BRANCH,		"branch"),
1094 #else
1095 # define BRANCH_FLAGS
1096 #endif
1097 
1098 #ifdef CONFIG_FUNCTION_TRACER
1099 # define FUNCTION_FLAGS						\
1100 		C(FUNCTION,		"function-trace"),	\
1101 		C(FUNC_FORK,		"function-fork"),
1102 # define FUNCTION_DEFAULT_FLAGS		TRACE_ITER_FUNCTION
1103 #else
1104 # define FUNCTION_FLAGS
1105 # define FUNCTION_DEFAULT_FLAGS		0UL
1106 # define TRACE_ITER_FUNC_FORK		0UL
1107 #endif
1108 
1109 #ifdef CONFIG_STACKTRACE
1110 # define STACK_FLAGS				\
1111 		C(STACKTRACE,		"stacktrace"),
1112 #else
1113 # define STACK_FLAGS
1114 #endif
1115 
1116 /*
1117  * trace_iterator_flags is an enumeration that defines bit
1118  * positions into trace_flags that controls the output.
1119  *
1120  * NOTE: These bits must match the trace_options array in
1121  *       trace.c (this macro guarantees it).
1122  */
1123 #define TRACE_FLAGS						\
1124 		C(PRINT_PARENT,		"print-parent"),	\
1125 		C(SYM_OFFSET,		"sym-offset"),		\
1126 		C(SYM_ADDR,		"sym-addr"),		\
1127 		C(VERBOSE,		"verbose"),		\
1128 		C(RAW,			"raw"),			\
1129 		C(HEX,			"hex"),			\
1130 		C(BIN,			"bin"),			\
1131 		C(BLOCK,		"block"),		\
1132 		C(PRINTK,		"trace_printk"),	\
1133 		C(ANNOTATE,		"annotate"),		\
1134 		C(USERSTACKTRACE,	"userstacktrace"),	\
1135 		C(SYM_USEROBJ,		"sym-userobj"),		\
1136 		C(PRINTK_MSGONLY,	"printk-msg-only"),	\
1137 		C(CONTEXT_INFO,		"context-info"),   /* Print pid/cpu/time */ \
1138 		C(LATENCY_FMT,		"latency-format"),	\
1139 		C(RECORD_CMD,		"record-cmd"),		\
1140 		C(RECORD_TGID,		"record-tgid"),		\
1141 		C(OVERWRITE,		"overwrite"),		\
1142 		C(STOP_ON_FREE,		"disable_on_free"),	\
1143 		C(IRQ_INFO,		"irq-info"),		\
1144 		C(MARKERS,		"markers"),		\
1145 		C(EVENT_FORK,		"event-fork"),		\
1146 		FUNCTION_FLAGS					\
1147 		FGRAPH_FLAGS					\
1148 		STACK_FLAGS					\
1149 		BRANCH_FLAGS
1150 
1151 /*
1152  * By defining C, we can make TRACE_FLAGS a list of bit names
1153  * that will define the bits for the flag masks.
1154  */
1155 #undef C
1156 #define C(a, b) TRACE_ITER_##a##_BIT
1157 
1158 enum trace_iterator_bits {
1159 	TRACE_FLAGS
1160 	/* Make sure we don't go more than we have bits for */
1161 	TRACE_ITER_LAST_BIT
1162 };
1163 
1164 /*
1165  * By redefining C, we can make TRACE_FLAGS a list of masks that
1166  * use the bits as defined above.
1167  */
1168 #undef C
1169 #define C(a, b) TRACE_ITER_##a = (1 << TRACE_ITER_##a##_BIT)
1170 
1171 enum trace_iterator_flags { TRACE_FLAGS };
1172 
1173 /*
1174  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
1175  * control the output of kernel symbols.
1176  */
1177 #define TRACE_ITER_SYM_MASK \
1178 	(TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
1179 
1180 extern struct tracer nop_trace;
1181 
1182 #ifdef CONFIG_BRANCH_TRACER
1183 extern int enable_branch_tracing(struct trace_array *tr);
1184 extern void disable_branch_tracing(void);
1185 static inline int trace_branch_enable(struct trace_array *tr)
1186 {
1187 	if (tr->trace_flags & TRACE_ITER_BRANCH)
1188 		return enable_branch_tracing(tr);
1189 	return 0;
1190 }
1191 static inline void trace_branch_disable(void)
1192 {
1193 	/* due to races, always disable */
1194 	disable_branch_tracing();
1195 }
1196 #else
1197 static inline int trace_branch_enable(struct trace_array *tr)
1198 {
1199 	return 0;
1200 }
1201 static inline void trace_branch_disable(void)
1202 {
1203 }
1204 #endif /* CONFIG_BRANCH_TRACER */
1205 
1206 /* set ring buffers to default size if not already done so */
1207 int tracing_update_buffers(void);
1208 
1209 struct ftrace_event_field {
1210 	struct list_head	link;
1211 	const char		*name;
1212 	const char		*type;
1213 	int			filter_type;
1214 	int			offset;
1215 	int			size;
1216 	int			is_signed;
1217 };
1218 
1219 struct prog_entry;
1220 
1221 struct event_filter {
1222 	struct prog_entry __rcu	*prog;
1223 	char			*filter_string;
1224 };
1225 
1226 struct event_subsystem {
1227 	struct list_head	list;
1228 	const char		*name;
1229 	struct event_filter	*filter;
1230 	int			ref_count;
1231 };
1232 
1233 struct trace_subsystem_dir {
1234 	struct list_head		list;
1235 	struct event_subsystem		*subsystem;
1236 	struct trace_array		*tr;
1237 	struct dentry			*entry;
1238 	int				ref_count;
1239 	int				nr_events;
1240 };
1241 
1242 extern int call_filter_check_discard(struct trace_event_call *call, void *rec,
1243 				     struct ring_buffer *buffer,
1244 				     struct ring_buffer_event *event);
1245 
1246 void trace_buffer_unlock_commit_regs(struct trace_array *tr,
1247 				     struct ring_buffer *buffer,
1248 				     struct ring_buffer_event *event,
1249 				     unsigned long flags, int pc,
1250 				     struct pt_regs *regs);
1251 
1252 static inline void trace_buffer_unlock_commit(struct trace_array *tr,
1253 					      struct ring_buffer *buffer,
1254 					      struct ring_buffer_event *event,
1255 					      unsigned long flags, int pc)
1256 {
1257 	trace_buffer_unlock_commit_regs(tr, buffer, event, flags, pc, NULL);
1258 }
1259 
1260 DECLARE_PER_CPU(struct ring_buffer_event *, trace_buffered_event);
1261 DECLARE_PER_CPU(int, trace_buffered_event_cnt);
1262 void trace_buffered_event_disable(void);
1263 void trace_buffered_event_enable(void);
1264 
1265 static inline void
1266 __trace_event_discard_commit(struct ring_buffer *buffer,
1267 			     struct ring_buffer_event *event)
1268 {
1269 	if (this_cpu_read(trace_buffered_event) == event) {
1270 		/* Simply release the temp buffer */
1271 		this_cpu_dec(trace_buffered_event_cnt);
1272 		return;
1273 	}
1274 	ring_buffer_discard_commit(buffer, event);
1275 }
1276 
1277 /*
1278  * Helper function for event_trigger_unlock_commit{_regs}().
1279  * If there are event triggers attached to this event that requires
1280  * filtering against its fields, then they wil be called as the
1281  * entry already holds the field information of the current event.
1282  *
1283  * It also checks if the event should be discarded or not.
1284  * It is to be discarded if the event is soft disabled and the
1285  * event was only recorded to process triggers, or if the event
1286  * filter is active and this event did not match the filters.
1287  *
1288  * Returns true if the event is discarded, false otherwise.
1289  */
1290 static inline bool
1291 __event_trigger_test_discard(struct trace_event_file *file,
1292 			     struct ring_buffer *buffer,
1293 			     struct ring_buffer_event *event,
1294 			     void *entry,
1295 			     enum event_trigger_type *tt)
1296 {
1297 	unsigned long eflags = file->flags;
1298 
1299 	if (eflags & EVENT_FILE_FL_TRIGGER_COND)
1300 		*tt = event_triggers_call(file, entry, event);
1301 
1302 	if (test_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags) ||
1303 	    (unlikely(file->flags & EVENT_FILE_FL_FILTERED) &&
1304 	     !filter_match_preds(file->filter, entry))) {
1305 		__trace_event_discard_commit(buffer, event);
1306 		return true;
1307 	}
1308 
1309 	return false;
1310 }
1311 
1312 /**
1313  * event_trigger_unlock_commit - handle triggers and finish event commit
1314  * @file: The file pointer assoctiated to the event
1315  * @buffer: The ring buffer that the event is being written to
1316  * @event: The event meta data in the ring buffer
1317  * @entry: The event itself
1318  * @irq_flags: The state of the interrupts at the start of the event
1319  * @pc: The state of the preempt count at the start of the event.
1320  *
1321  * This is a helper function to handle triggers that require data
1322  * from the event itself. It also tests the event against filters and
1323  * if the event is soft disabled and should be discarded.
1324  */
1325 static inline void
1326 event_trigger_unlock_commit(struct trace_event_file *file,
1327 			    struct ring_buffer *buffer,
1328 			    struct ring_buffer_event *event,
1329 			    void *entry, unsigned long irq_flags, int pc)
1330 {
1331 	enum event_trigger_type tt = ETT_NONE;
1332 
1333 	if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1334 		trace_buffer_unlock_commit(file->tr, buffer, event, irq_flags, pc);
1335 
1336 	if (tt)
1337 		event_triggers_post_call(file, tt, entry, event);
1338 }
1339 
1340 /**
1341  * event_trigger_unlock_commit_regs - handle triggers and finish event commit
1342  * @file: The file pointer assoctiated to the event
1343  * @buffer: The ring buffer that the event is being written to
1344  * @event: The event meta data in the ring buffer
1345  * @entry: The event itself
1346  * @irq_flags: The state of the interrupts at the start of the event
1347  * @pc: The state of the preempt count at the start of the event.
1348  *
1349  * This is a helper function to handle triggers that require data
1350  * from the event itself. It also tests the event against filters and
1351  * if the event is soft disabled and should be discarded.
1352  *
1353  * Same as event_trigger_unlock_commit() but calls
1354  * trace_buffer_unlock_commit_regs() instead of trace_buffer_unlock_commit().
1355  */
1356 static inline void
1357 event_trigger_unlock_commit_regs(struct trace_event_file *file,
1358 				 struct ring_buffer *buffer,
1359 				 struct ring_buffer_event *event,
1360 				 void *entry, unsigned long irq_flags, int pc,
1361 				 struct pt_regs *regs)
1362 {
1363 	enum event_trigger_type tt = ETT_NONE;
1364 
1365 	if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1366 		trace_buffer_unlock_commit_regs(file->tr, buffer, event,
1367 						irq_flags, pc, regs);
1368 
1369 	if (tt)
1370 		event_triggers_post_call(file, tt, entry, event);
1371 }
1372 
1373 #define FILTER_PRED_INVALID	((unsigned short)-1)
1374 #define FILTER_PRED_IS_RIGHT	(1 << 15)
1375 #define FILTER_PRED_FOLD	(1 << 15)
1376 
1377 /*
1378  * The max preds is the size of unsigned short with
1379  * two flags at the MSBs. One bit is used for both the IS_RIGHT
1380  * and FOLD flags. The other is reserved.
1381  *
1382  * 2^14 preds is way more than enough.
1383  */
1384 #define MAX_FILTER_PRED		16384
1385 
1386 struct filter_pred;
1387 struct regex;
1388 
1389 typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event);
1390 
1391 typedef int (*regex_match_func)(char *str, struct regex *r, int len);
1392 
1393 enum regex_type {
1394 	MATCH_FULL = 0,
1395 	MATCH_FRONT_ONLY,
1396 	MATCH_MIDDLE_ONLY,
1397 	MATCH_END_ONLY,
1398 	MATCH_GLOB,
1399 };
1400 
1401 struct regex {
1402 	char			pattern[MAX_FILTER_STR_VAL];
1403 	int			len;
1404 	int			field_len;
1405 	regex_match_func	match;
1406 };
1407 
1408 struct filter_pred {
1409 	filter_pred_fn_t 	fn;
1410 	u64 			val;
1411 	struct regex		regex;
1412 	unsigned short		*ops;
1413 	struct ftrace_event_field *field;
1414 	int 			offset;
1415 	int			not;
1416 	int 			op;
1417 };
1418 
1419 static inline bool is_string_field(struct ftrace_event_field *field)
1420 {
1421 	return field->filter_type == FILTER_DYN_STRING ||
1422 	       field->filter_type == FILTER_STATIC_STRING ||
1423 	       field->filter_type == FILTER_PTR_STRING ||
1424 	       field->filter_type == FILTER_COMM;
1425 }
1426 
1427 static inline bool is_function_field(struct ftrace_event_field *field)
1428 {
1429 	return field->filter_type == FILTER_TRACE_FN;
1430 }
1431 
1432 extern enum regex_type
1433 filter_parse_regex(char *buff, int len, char **search, int *not);
1434 extern void print_event_filter(struct trace_event_file *file,
1435 			       struct trace_seq *s);
1436 extern int apply_event_filter(struct trace_event_file *file,
1437 			      char *filter_string);
1438 extern int apply_subsystem_event_filter(struct trace_subsystem_dir *dir,
1439 					char *filter_string);
1440 extern void print_subsystem_event_filter(struct event_subsystem *system,
1441 					 struct trace_seq *s);
1442 extern int filter_assign_type(const char *type);
1443 extern int create_event_filter(struct trace_event_call *call,
1444 			       char *filter_str, bool set_str,
1445 			       struct event_filter **filterp);
1446 extern void free_event_filter(struct event_filter *filter);
1447 
1448 struct ftrace_event_field *
1449 trace_find_event_field(struct trace_event_call *call, char *name);
1450 
1451 extern void trace_event_enable_cmd_record(bool enable);
1452 extern void trace_event_enable_tgid_record(bool enable);
1453 
1454 extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
1455 extern int event_trace_del_tracer(struct trace_array *tr);
1456 
1457 extern struct trace_event_file *find_event_file(struct trace_array *tr,
1458 						const char *system,
1459 						const char *event);
1460 
1461 static inline void *event_file_data(struct file *filp)
1462 {
1463 	return READ_ONCE(file_inode(filp)->i_private);
1464 }
1465 
1466 extern struct mutex event_mutex;
1467 extern struct list_head ftrace_events;
1468 
1469 extern const struct file_operations event_trigger_fops;
1470 extern const struct file_operations event_hist_fops;
1471 
1472 #ifdef CONFIG_HIST_TRIGGERS
1473 extern int register_trigger_hist_cmd(void);
1474 extern int register_trigger_hist_enable_disable_cmds(void);
1475 #else
1476 static inline int register_trigger_hist_cmd(void) { return 0; }
1477 static inline int register_trigger_hist_enable_disable_cmds(void) { return 0; }
1478 #endif
1479 
1480 extern int register_trigger_cmds(void);
1481 extern void clear_event_triggers(struct trace_array *tr);
1482 
1483 struct event_trigger_data {
1484 	unsigned long			count;
1485 	int				ref;
1486 	struct event_trigger_ops	*ops;
1487 	struct event_command		*cmd_ops;
1488 	struct event_filter __rcu	*filter;
1489 	char				*filter_str;
1490 	void				*private_data;
1491 	bool				paused;
1492 	bool				paused_tmp;
1493 	struct list_head		list;
1494 	char				*name;
1495 	struct list_head		named_list;
1496 	struct event_trigger_data	*named_data;
1497 };
1498 
1499 /* Avoid typos */
1500 #define ENABLE_EVENT_STR	"enable_event"
1501 #define DISABLE_EVENT_STR	"disable_event"
1502 #define ENABLE_HIST_STR		"enable_hist"
1503 #define DISABLE_HIST_STR	"disable_hist"
1504 
1505 struct enable_trigger_data {
1506 	struct trace_event_file		*file;
1507 	bool				enable;
1508 	bool				hist;
1509 };
1510 
1511 extern int event_enable_trigger_print(struct seq_file *m,
1512 				      struct event_trigger_ops *ops,
1513 				      struct event_trigger_data *data);
1514 extern void event_enable_trigger_free(struct event_trigger_ops *ops,
1515 				      struct event_trigger_data *data);
1516 extern int event_enable_trigger_func(struct event_command *cmd_ops,
1517 				     struct trace_event_file *file,
1518 				     char *glob, char *cmd, char *param);
1519 extern int event_enable_register_trigger(char *glob,
1520 					 struct event_trigger_ops *ops,
1521 					 struct event_trigger_data *data,
1522 					 struct trace_event_file *file);
1523 extern void event_enable_unregister_trigger(char *glob,
1524 					    struct event_trigger_ops *ops,
1525 					    struct event_trigger_data *test,
1526 					    struct trace_event_file *file);
1527 extern void trigger_data_free(struct event_trigger_data *data);
1528 extern int event_trigger_init(struct event_trigger_ops *ops,
1529 			      struct event_trigger_data *data);
1530 extern int trace_event_trigger_enable_disable(struct trace_event_file *file,
1531 					      int trigger_enable);
1532 extern void update_cond_flag(struct trace_event_file *file);
1533 extern void unregister_trigger(char *glob, struct event_trigger_ops *ops,
1534 			       struct event_trigger_data *test,
1535 			       struct trace_event_file *file);
1536 extern int set_trigger_filter(char *filter_str,
1537 			      struct event_trigger_data *trigger_data,
1538 			      struct trace_event_file *file);
1539 extern struct event_trigger_data *find_named_trigger(const char *name);
1540 extern bool is_named_trigger(struct event_trigger_data *test);
1541 extern int save_named_trigger(const char *name,
1542 			      struct event_trigger_data *data);
1543 extern void del_named_trigger(struct event_trigger_data *data);
1544 extern void pause_named_trigger(struct event_trigger_data *data);
1545 extern void unpause_named_trigger(struct event_trigger_data *data);
1546 extern void set_named_trigger_data(struct event_trigger_data *data,
1547 				   struct event_trigger_data *named_data);
1548 extern struct event_trigger_data *
1549 get_named_trigger_data(struct event_trigger_data *data);
1550 extern int register_event_command(struct event_command *cmd);
1551 extern int unregister_event_command(struct event_command *cmd);
1552 extern int register_trigger_hist_enable_disable_cmds(void);
1553 
1554 /**
1555  * struct event_trigger_ops - callbacks for trace event triggers
1556  *
1557  * The methods in this structure provide per-event trigger hooks for
1558  * various trigger operations.
1559  *
1560  * All the methods below, except for @init() and @free(), must be
1561  * implemented.
1562  *
1563  * @func: The trigger 'probe' function called when the triggering
1564  *	event occurs.  The data passed into this callback is the data
1565  *	that was supplied to the event_command @reg() function that
1566  *	registered the trigger (see struct event_command) along with
1567  *	the trace record, rec.
1568  *
1569  * @init: An optional initialization function called for the trigger
1570  *	when the trigger is registered (via the event_command reg()
1571  *	function).  This can be used to perform per-trigger
1572  *	initialization such as incrementing a per-trigger reference
1573  *	count, for instance.  This is usually implemented by the
1574  *	generic utility function @event_trigger_init() (see
1575  *	trace_event_triggers.c).
1576  *
1577  * @free: An optional de-initialization function called for the
1578  *	trigger when the trigger is unregistered (via the
1579  *	event_command @reg() function).  This can be used to perform
1580  *	per-trigger de-initialization such as decrementing a
1581  *	per-trigger reference count and freeing corresponding trigger
1582  *	data, for instance.  This is usually implemented by the
1583  *	generic utility function @event_trigger_free() (see
1584  *	trace_event_triggers.c).
1585  *
1586  * @print: The callback function invoked to have the trigger print
1587  *	itself.  This is usually implemented by a wrapper function
1588  *	that calls the generic utility function @event_trigger_print()
1589  *	(see trace_event_triggers.c).
1590  */
1591 struct event_trigger_ops {
1592 	void			(*func)(struct event_trigger_data *data,
1593 					void *rec,
1594 					struct ring_buffer_event *rbe);
1595 	int			(*init)(struct event_trigger_ops *ops,
1596 					struct event_trigger_data *data);
1597 	void			(*free)(struct event_trigger_ops *ops,
1598 					struct event_trigger_data *data);
1599 	int			(*print)(struct seq_file *m,
1600 					 struct event_trigger_ops *ops,
1601 					 struct event_trigger_data *data);
1602 };
1603 
1604 /**
1605  * struct event_command - callbacks and data members for event commands
1606  *
1607  * Event commands are invoked by users by writing the command name
1608  * into the 'trigger' file associated with a trace event.  The
1609  * parameters associated with a specific invocation of an event
1610  * command are used to create an event trigger instance, which is
1611  * added to the list of trigger instances associated with that trace
1612  * event.  When the event is hit, the set of triggers associated with
1613  * that event is invoked.
1614  *
1615  * The data members in this structure provide per-event command data
1616  * for various event commands.
1617  *
1618  * All the data members below, except for @post_trigger, must be set
1619  * for each event command.
1620  *
1621  * @name: The unique name that identifies the event command.  This is
1622  *	the name used when setting triggers via trigger files.
1623  *
1624  * @trigger_type: A unique id that identifies the event command
1625  *	'type'.  This value has two purposes, the first to ensure that
1626  *	only one trigger of the same type can be set at a given time
1627  *	for a particular event e.g. it doesn't make sense to have both
1628  *	a traceon and traceoff trigger attached to a single event at
1629  *	the same time, so traceon and traceoff have the same type
1630  *	though they have different names.  The @trigger_type value is
1631  *	also used as a bit value for deferring the actual trigger
1632  *	action until after the current event is finished.  Some
1633  *	commands need to do this if they themselves log to the trace
1634  *	buffer (see the @post_trigger() member below).  @trigger_type
1635  *	values are defined by adding new values to the trigger_type
1636  *	enum in include/linux/trace_events.h.
1637  *
1638  * @flags: See the enum event_command_flags below.
1639  *
1640  * All the methods below, except for @set_filter() and @unreg_all(),
1641  * must be implemented.
1642  *
1643  * @func: The callback function responsible for parsing and
1644  *	registering the trigger written to the 'trigger' file by the
1645  *	user.  It allocates the trigger instance and registers it with
1646  *	the appropriate trace event.  It makes use of the other
1647  *	event_command callback functions to orchestrate this, and is
1648  *	usually implemented by the generic utility function
1649  *	@event_trigger_callback() (see trace_event_triggers.c).
1650  *
1651  * @reg: Adds the trigger to the list of triggers associated with the
1652  *	event, and enables the event trigger itself, after
1653  *	initializing it (via the event_trigger_ops @init() function).
1654  *	This is also where commands can use the @trigger_type value to
1655  *	make the decision as to whether or not multiple instances of
1656  *	the trigger should be allowed.  This is usually implemented by
1657  *	the generic utility function @register_trigger() (see
1658  *	trace_event_triggers.c).
1659  *
1660  * @unreg: Removes the trigger from the list of triggers associated
1661  *	with the event, and disables the event trigger itself, after
1662  *	initializing it (via the event_trigger_ops @free() function).
1663  *	This is usually implemented by the generic utility function
1664  *	@unregister_trigger() (see trace_event_triggers.c).
1665  *
1666  * @unreg_all: An optional function called to remove all the triggers
1667  *	from the list of triggers associated with the event.  Called
1668  *	when a trigger file is opened in truncate mode.
1669  *
1670  * @set_filter: An optional function called to parse and set a filter
1671  *	for the trigger.  If no @set_filter() method is set for the
1672  *	event command, filters set by the user for the command will be
1673  *	ignored.  This is usually implemented by the generic utility
1674  *	function @set_trigger_filter() (see trace_event_triggers.c).
1675  *
1676  * @get_trigger_ops: The callback function invoked to retrieve the
1677  *	event_trigger_ops implementation associated with the command.
1678  */
1679 struct event_command {
1680 	struct list_head	list;
1681 	char			*name;
1682 	enum event_trigger_type	trigger_type;
1683 	int			flags;
1684 	int			(*func)(struct event_command *cmd_ops,
1685 					struct trace_event_file *file,
1686 					char *glob, char *cmd, char *params);
1687 	int			(*reg)(char *glob,
1688 				       struct event_trigger_ops *ops,
1689 				       struct event_trigger_data *data,
1690 				       struct trace_event_file *file);
1691 	void			(*unreg)(char *glob,
1692 					 struct event_trigger_ops *ops,
1693 					 struct event_trigger_data *data,
1694 					 struct trace_event_file *file);
1695 	void			(*unreg_all)(struct trace_event_file *file);
1696 	int			(*set_filter)(char *filter_str,
1697 					      struct event_trigger_data *data,
1698 					      struct trace_event_file *file);
1699 	struct event_trigger_ops *(*get_trigger_ops)(char *cmd, char *param);
1700 };
1701 
1702 /**
1703  * enum event_command_flags - flags for struct event_command
1704  *
1705  * @POST_TRIGGER: A flag that says whether or not this command needs
1706  *	to have its action delayed until after the current event has
1707  *	been closed.  Some triggers need to avoid being invoked while
1708  *	an event is currently in the process of being logged, since
1709  *	the trigger may itself log data into the trace buffer.  Thus
1710  *	we make sure the current event is committed before invoking
1711  *	those triggers.  To do that, the trigger invocation is split
1712  *	in two - the first part checks the filter using the current
1713  *	trace record; if a command has the @post_trigger flag set, it
1714  *	sets a bit for itself in the return value, otherwise it
1715  *	directly invokes the trigger.  Once all commands have been
1716  *	either invoked or set their return flag, the current record is
1717  *	either committed or discarded.  At that point, if any commands
1718  *	have deferred their triggers, those commands are finally
1719  *	invoked following the close of the current event.  In other
1720  *	words, if the event_trigger_ops @func() probe implementation
1721  *	itself logs to the trace buffer, this flag should be set,
1722  *	otherwise it can be left unspecified.
1723  *
1724  * @NEEDS_REC: A flag that says whether or not this command needs
1725  *	access to the trace record in order to perform its function,
1726  *	regardless of whether or not it has a filter associated with
1727  *	it (filters make a trigger require access to the trace record
1728  *	but are not always present).
1729  */
1730 enum event_command_flags {
1731 	EVENT_CMD_FL_POST_TRIGGER	= 1,
1732 	EVENT_CMD_FL_NEEDS_REC		= 2,
1733 };
1734 
1735 static inline bool event_command_post_trigger(struct event_command *cmd_ops)
1736 {
1737 	return cmd_ops->flags & EVENT_CMD_FL_POST_TRIGGER;
1738 }
1739 
1740 static inline bool event_command_needs_rec(struct event_command *cmd_ops)
1741 {
1742 	return cmd_ops->flags & EVENT_CMD_FL_NEEDS_REC;
1743 }
1744 
1745 extern int trace_event_enable_disable(struct trace_event_file *file,
1746 				      int enable, int soft_disable);
1747 extern int tracing_alloc_snapshot(void);
1748 
1749 extern const char *__start___trace_bprintk_fmt[];
1750 extern const char *__stop___trace_bprintk_fmt[];
1751 
1752 extern const char *__start___tracepoint_str[];
1753 extern const char *__stop___tracepoint_str[];
1754 
1755 void trace_printk_control(bool enabled);
1756 void trace_printk_init_buffers(void);
1757 void trace_printk_start_comm(void);
1758 int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set);
1759 int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled);
1760 
1761 #define MAX_EVENT_NAME_LEN	64
1762 
1763 extern int trace_run_command(const char *buf, int (*createfn)(int, char**));
1764 extern ssize_t trace_parse_run_command(struct file *file,
1765 		const char __user *buffer, size_t count, loff_t *ppos,
1766 		int (*createfn)(int, char**));
1767 
1768 /*
1769  * Normal trace_printk() and friends allocates special buffers
1770  * to do the manipulation, as well as saves the print formats
1771  * into sections to display. But the trace infrastructure wants
1772  * to use these without the added overhead at the price of being
1773  * a bit slower (used mainly for warnings, where we don't care
1774  * about performance). The internal_trace_puts() is for such
1775  * a purpose.
1776  */
1777 #define internal_trace_puts(str) __trace_puts(_THIS_IP_, str, strlen(str))
1778 
1779 #undef FTRACE_ENTRY
1780 #define FTRACE_ENTRY(call, struct_name, id, tstruct, print, filter)	\
1781 	extern struct trace_event_call					\
1782 	__aligned(4) event_##call;
1783 #undef FTRACE_ENTRY_DUP
1784 #define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print, filter)	\
1785 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print), \
1786 		     filter)
1787 #undef FTRACE_ENTRY_PACKED
1788 #define FTRACE_ENTRY_PACKED(call, struct_name, id, tstruct, print, filter) \
1789 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print), \
1790 		     filter)
1791 
1792 #include "trace_entries.h"
1793 
1794 #if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_FUNCTION_TRACER)
1795 int perf_ftrace_event_register(struct trace_event_call *call,
1796 			       enum trace_reg type, void *data);
1797 #else
1798 #define perf_ftrace_event_register NULL
1799 #endif
1800 
1801 #ifdef CONFIG_FTRACE_SYSCALLS
1802 void init_ftrace_syscalls(void);
1803 const char *get_syscall_name(int syscall);
1804 #else
1805 static inline void init_ftrace_syscalls(void) { }
1806 static inline const char *get_syscall_name(int syscall)
1807 {
1808 	return NULL;
1809 }
1810 #endif
1811 
1812 #ifdef CONFIG_EVENT_TRACING
1813 void trace_event_init(void);
1814 void trace_event_eval_update(struct trace_eval_map **map, int len);
1815 #else
1816 static inline void __init trace_event_init(void) { }
1817 static inline void trace_event_eval_update(struct trace_eval_map **map, int len) { }
1818 #endif
1819 
1820 extern struct trace_iterator *tracepoint_print_iter;
1821 
1822 #endif /* _LINUX_KERNEL_TRACE_H */
1823