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