xref: /openbmc/linux/kernel/trace/trace.h (revision 91edde2e6ae1dd5e33812f076f3fe4cb7ccbfdd0)
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/glob.h>
19 #include <linux/irq_work.h>
20 #include <linux/workqueue.h>
21 
22 #ifdef CONFIG_FTRACE_SYSCALLS
23 #include <asm/unistd.h>		/* For NR_SYSCALLS	     */
24 #include <asm/syscall.h>	/* some archs define it here */
25 #endif
26 
27 enum trace_type {
28 	__TRACE_FIRST_TYPE = 0,
29 
30 	TRACE_FN,
31 	TRACE_CTX,
32 	TRACE_WAKE,
33 	TRACE_STACK,
34 	TRACE_PRINT,
35 	TRACE_BPRINT,
36 	TRACE_MMIO_RW,
37 	TRACE_MMIO_MAP,
38 	TRACE_BRANCH,
39 	TRACE_GRAPH_RET,
40 	TRACE_GRAPH_ENT,
41 	TRACE_USER_STACK,
42 	TRACE_BLK,
43 	TRACE_BPUTS,
44 	TRACE_HWLAT,
45 	TRACE_RAW_DATA,
46 
47 	__TRACE_LAST_TYPE,
48 };
49 
50 
51 #undef __field
52 #define __field(type, item)		type	item;
53 
54 #undef __field_struct
55 #define __field_struct(type, item)	__field(type, item)
56 
57 #undef __field_desc
58 #define __field_desc(type, container, item)
59 
60 #undef __array
61 #define __array(type, item, size)	type	item[size];
62 
63 #undef __array_desc
64 #define __array_desc(type, container, item, size)
65 
66 #undef __dynamic_array
67 #define __dynamic_array(type, item)	type	item[];
68 
69 #undef F_STRUCT
70 #define F_STRUCT(args...)		args
71 
72 #undef FTRACE_ENTRY
73 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print, filter)	\
74 	struct struct_name {						\
75 		struct trace_entry	ent;				\
76 		tstruct							\
77 	}
78 
79 #undef FTRACE_ENTRY_DUP
80 #define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk, filter)
81 
82 #undef FTRACE_ENTRY_REG
83 #define FTRACE_ENTRY_REG(name, struct_name, id, tstruct, print,	\
84 			 filter, regfn) \
85 	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print), \
86 		     filter)
87 
88 #undef FTRACE_ENTRY_PACKED
89 #define FTRACE_ENTRY_PACKED(name, struct_name, id, tstruct, print,	\
90 			    filter)					\
91 	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print), \
92 		     filter) __packed
93 
94 #include "trace_entries.h"
95 
96 /*
97  * syscalls are special, and need special handling, this is why
98  * they are not included in trace_entries.h
99  */
100 struct syscall_trace_enter {
101 	struct trace_entry	ent;
102 	int			nr;
103 	unsigned long		args[];
104 };
105 
106 struct syscall_trace_exit {
107 	struct trace_entry	ent;
108 	int			nr;
109 	long			ret;
110 };
111 
112 struct kprobe_trace_entry_head {
113 	struct trace_entry	ent;
114 	unsigned long		ip;
115 };
116 
117 struct kretprobe_trace_entry_head {
118 	struct trace_entry	ent;
119 	unsigned long		func;
120 	unsigned long		ret_ip;
121 };
122 
123 /*
124  * trace_flag_type is an enumeration that holds different
125  * states when a trace occurs. These are:
126  *  IRQS_OFF		- interrupts were disabled
127  *  IRQS_NOSUPPORT	- arch does not support irqs_disabled_flags
128  *  NEED_RESCHED	- reschedule is requested
129  *  HARDIRQ		- inside an interrupt handler
130  *  SOFTIRQ		- inside a softirq handler
131  */
132 enum trace_flag_type {
133 	TRACE_FLAG_IRQS_OFF		= 0x01,
134 	TRACE_FLAG_IRQS_NOSUPPORT	= 0x02,
135 	TRACE_FLAG_NEED_RESCHED		= 0x04,
136 	TRACE_FLAG_HARDIRQ		= 0x08,
137 	TRACE_FLAG_SOFTIRQ		= 0x10,
138 	TRACE_FLAG_PREEMPT_RESCHED	= 0x20,
139 	TRACE_FLAG_NMI			= 0x40,
140 };
141 
142 #define TRACE_BUF_SIZE		1024
143 
144 struct trace_array;
145 
146 /*
147  * The CPU trace array - it consists of thousands of trace entries
148  * plus some other descriptor data: (for example which task started
149  * the trace, etc.)
150  */
151 struct trace_array_cpu {
152 	atomic_t		disabled;
153 	void			*buffer_page;	/* ring buffer spare */
154 
155 	unsigned long		entries;
156 	unsigned long		saved_latency;
157 	unsigned long		critical_start;
158 	unsigned long		critical_end;
159 	unsigned long		critical_sequence;
160 	unsigned long		nice;
161 	unsigned long		policy;
162 	unsigned long		rt_priority;
163 	unsigned long		skipped_entries;
164 	u64			preempt_timestamp;
165 	pid_t			pid;
166 	kuid_t			uid;
167 	char			comm[TASK_COMM_LEN];
168 
169 	bool			ignore_pid;
170 #ifdef CONFIG_FUNCTION_TRACER
171 	bool			ftrace_ignore_pid;
172 #endif
173 };
174 
175 struct tracer;
176 struct trace_option_dentry;
177 
178 struct trace_buffer {
179 	struct trace_array		*tr;
180 	struct ring_buffer		*buffer;
181 	struct trace_array_cpu __percpu	*data;
182 	u64				time_start;
183 	int				cpu;
184 };
185 
186 #define TRACE_FLAGS_MAX_SIZE		32
187 
188 struct trace_options {
189 	struct tracer			*tracer;
190 	struct trace_option_dentry	*topts;
191 };
192 
193 struct trace_pid_list {
194 	int				pid_max;
195 	unsigned long			*pids;
196 };
197 
198 typedef bool (*cond_update_fn_t)(struct trace_array *tr, void *cond_data);
199 
200 /**
201  * struct cond_snapshot - conditional snapshot data and callback
202  *
203  * The cond_snapshot structure encapsulates a callback function and
204  * data associated with the snapshot for a given tracing instance.
205  *
206  * When a snapshot is taken conditionally, by invoking
207  * tracing_snapshot_cond(tr, cond_data), the cond_data passed in is
208  * passed in turn to the cond_snapshot.update() function.  That data
209  * can be compared by the update() implementation with the cond_data
210  * contained wihin the struct cond_snapshot instance associated with
211  * the trace_array.  Because the tr->max_lock is held throughout the
212  * update() call, the update() function can directly retrieve the
213  * cond_snapshot and cond_data associated with the per-instance
214  * snapshot associated with the trace_array.
215  *
216  * The cond_snapshot.update() implementation can save data to be
217  * associated with the snapshot if it decides to, and returns 'true'
218  * in that case, or it returns 'false' if the conditional snapshot
219  * shouldn't be taken.
220  *
221  * The cond_snapshot instance is created and associated with the
222  * user-defined cond_data by tracing_cond_snapshot_enable().
223  * Likewise, the cond_snapshot instance is destroyed and is no longer
224  * associated with the trace instance by
225  * tracing_cond_snapshot_disable().
226  *
227  * The method below is required.
228  *
229  * @update: When a conditional snapshot is invoked, the update()
230  *	callback function is invoked with the tr->max_lock held.  The
231  *	update() implementation signals whether or not to actually
232  *	take the snapshot, by returning 'true' if so, 'false' if no
233  *	snapshot should be taken.  Because the max_lock is held for
234  *	the duration of update(), the implementation is safe to
235  *	directly retrieven and save any implementation data it needs
236  *	to in association with the snapshot.
237  */
238 struct cond_snapshot {
239 	void				*cond_data;
240 	cond_update_fn_t		update;
241 };
242 
243 /*
244  * The trace array - an array of per-CPU trace arrays. This is the
245  * highest level data structure that individual tracers deal with.
246  * They have on/off state as well:
247  */
248 struct trace_array {
249 	struct list_head	list;
250 	char			*name;
251 	struct trace_buffer	trace_buffer;
252 #ifdef CONFIG_TRACER_MAX_TRACE
253 	/*
254 	 * The max_buffer is used to snapshot the trace when a maximum
255 	 * latency is reached, or when the user initiates a snapshot.
256 	 * Some tracers will use this to store a maximum trace while
257 	 * it continues examining live traces.
258 	 *
259 	 * The buffers for the max_buffer are set up the same as the trace_buffer
260 	 * When a snapshot is taken, the buffer of the max_buffer is swapped
261 	 * with the buffer of the trace_buffer and the buffers are reset for
262 	 * the trace_buffer so the tracing can continue.
263 	 */
264 	struct trace_buffer	max_buffer;
265 	bool			allocated_snapshot;
266 #endif
267 #if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)
268 	unsigned long		max_latency;
269 #ifdef CONFIG_FSNOTIFY
270 	struct dentry		*d_max_latency;
271 	struct work_struct	fsnotify_work;
272 	struct irq_work		fsnotify_irqwork;
273 #endif
274 #endif
275 	struct trace_pid_list	__rcu *filtered_pids;
276 	/*
277 	 * max_lock is used to protect the swapping of buffers
278 	 * when taking a max snapshot. The buffers themselves are
279 	 * protected by per_cpu spinlocks. But the action of the swap
280 	 * needs its own lock.
281 	 *
282 	 * This is defined as a arch_spinlock_t in order to help
283 	 * with performance when lockdep debugging is enabled.
284 	 *
285 	 * It is also used in other places outside the update_max_tr
286 	 * so it needs to be defined outside of the
287 	 * CONFIG_TRACER_MAX_TRACE.
288 	 */
289 	arch_spinlock_t		max_lock;
290 	int			buffer_disabled;
291 #ifdef CONFIG_FTRACE_SYSCALLS
292 	int			sys_refcount_enter;
293 	int			sys_refcount_exit;
294 	struct trace_event_file __rcu *enter_syscall_files[NR_syscalls];
295 	struct trace_event_file __rcu *exit_syscall_files[NR_syscalls];
296 #endif
297 	int			stop_count;
298 	int			clock_id;
299 	int			nr_topts;
300 	bool			clear_trace;
301 	int			buffer_percent;
302 	unsigned int		n_err_log_entries;
303 	struct tracer		*current_trace;
304 	unsigned int		trace_flags;
305 	unsigned char		trace_flags_index[TRACE_FLAGS_MAX_SIZE];
306 	unsigned int		flags;
307 	raw_spinlock_t		start_lock;
308 	struct list_head	err_log;
309 	struct dentry		*dir;
310 	struct dentry		*options;
311 	struct dentry		*percpu_dir;
312 	struct dentry		*event_dir;
313 	struct trace_options	*topts;
314 	struct list_head	systems;
315 	struct list_head	events;
316 	struct trace_event_file *trace_marker_file;
317 	cpumask_var_t		tracing_cpumask; /* only trace on set CPUs */
318 	int			ref;
319 #ifdef CONFIG_FUNCTION_TRACER
320 	struct ftrace_ops	*ops;
321 	struct trace_pid_list	__rcu *function_pids;
322 #ifdef CONFIG_DYNAMIC_FTRACE
323 	/* All of these are protected by the ftrace_lock */
324 	struct list_head	func_probes;
325 	struct list_head	mod_trace;
326 	struct list_head	mod_notrace;
327 #endif
328 	/* function tracing enabled */
329 	int			function_enabled;
330 #endif
331 	int			time_stamp_abs_ref;
332 	struct list_head	hist_vars;
333 #ifdef CONFIG_TRACER_SNAPSHOT
334 	struct cond_snapshot	*cond_snapshot;
335 #endif
336 };
337 
338 enum {
339 	TRACE_ARRAY_FL_GLOBAL	= (1 << 0)
340 };
341 
342 extern struct list_head ftrace_trace_arrays;
343 
344 extern struct mutex trace_types_lock;
345 
346 extern int trace_array_get(struct trace_array *tr);
347 extern void trace_array_put(struct trace_array *tr);
348 extern int tracing_check_open_get_tr(struct trace_array *tr);
349 
350 extern int tracing_set_time_stamp_abs(struct trace_array *tr, bool abs);
351 extern int tracing_set_clock(struct trace_array *tr, const char *clockstr);
352 
353 extern bool trace_clock_in_ns(struct trace_array *tr);
354 
355 /*
356  * The global tracer (top) should be the first trace array added,
357  * but we check the flag anyway.
358  */
359 static inline struct trace_array *top_trace_array(void)
360 {
361 	struct trace_array *tr;
362 
363 	if (list_empty(&ftrace_trace_arrays))
364 		return NULL;
365 
366 	tr = list_entry(ftrace_trace_arrays.prev,
367 			typeof(*tr), list);
368 	WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
369 	return tr;
370 }
371 
372 #define FTRACE_CMP_TYPE(var, type) \
373 	__builtin_types_compatible_p(typeof(var), type *)
374 
375 #undef IF_ASSIGN
376 #define IF_ASSIGN(var, entry, etype, id)			\
377 	if (FTRACE_CMP_TYPE(var, etype)) {			\
378 		var = (typeof(var))(entry);			\
379 		WARN_ON(id != 0 && (entry)->type != id);	\
380 		break;						\
381 	}
382 
383 /* Will cause compile errors if type is not found. */
384 extern void __ftrace_bad_type(void);
385 
386 /*
387  * The trace_assign_type is a verifier that the entry type is
388  * the same as the type being assigned. To add new types simply
389  * add a line with the following format:
390  *
391  * IF_ASSIGN(var, ent, type, id);
392  *
393  *  Where "type" is the trace type that includes the trace_entry
394  *  as the "ent" item. And "id" is the trace identifier that is
395  *  used in the trace_type enum.
396  *
397  *  If the type can have more than one id, then use zero.
398  */
399 #define trace_assign_type(var, ent)					\
400 	do {								\
401 		IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);	\
402 		IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);	\
403 		IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);	\
404 		IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
405 		IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);	\
406 		IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT);	\
407 		IF_ASSIGN(var, ent, struct bputs_entry, TRACE_BPUTS);	\
408 		IF_ASSIGN(var, ent, struct hwlat_entry, TRACE_HWLAT);	\
409 		IF_ASSIGN(var, ent, struct raw_data_entry, TRACE_RAW_DATA);\
410 		IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,		\
411 			  TRACE_MMIO_RW);				\
412 		IF_ASSIGN(var, ent, struct trace_mmiotrace_map,		\
413 			  TRACE_MMIO_MAP);				\
414 		IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
415 		IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,	\
416 			  TRACE_GRAPH_ENT);		\
417 		IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,	\
418 			  TRACE_GRAPH_RET);		\
419 		__ftrace_bad_type();					\
420 	} while (0)
421 
422 /*
423  * An option specific to a tracer. This is a boolean value.
424  * The bit is the bit index that sets its value on the
425  * flags value in struct tracer_flags.
426  */
427 struct tracer_opt {
428 	const char	*name; /* Will appear on the trace_options file */
429 	u32		bit; /* Mask assigned in val field in tracer_flags */
430 };
431 
432 /*
433  * The set of specific options for a tracer. Your tracer
434  * have to set the initial value of the flags val.
435  */
436 struct tracer_flags {
437 	u32			val;
438 	struct tracer_opt	*opts;
439 	struct tracer		*trace;
440 };
441 
442 /* Makes more easy to define a tracer opt */
443 #define TRACER_OPT(s, b)	.name = #s, .bit = b
444 
445 
446 struct trace_option_dentry {
447 	struct tracer_opt		*opt;
448 	struct tracer_flags		*flags;
449 	struct trace_array		*tr;
450 	struct dentry			*entry;
451 };
452 
453 /**
454  * struct tracer - a specific tracer and its callbacks to interact with tracefs
455  * @name: the name chosen to select it on the available_tracers file
456  * @init: called when one switches to this tracer (echo name > current_tracer)
457  * @reset: called when one switches to another tracer
458  * @start: called when tracing is unpaused (echo 1 > tracing_on)
459  * @stop: called when tracing is paused (echo 0 > tracing_on)
460  * @update_thresh: called when tracing_thresh is updated
461  * @open: called when the trace file is opened
462  * @pipe_open: called when the trace_pipe file is opened
463  * @close: called when the trace file is released
464  * @pipe_close: called when the trace_pipe file is released
465  * @read: override the default read callback on trace_pipe
466  * @splice_read: override the default splice_read callback on trace_pipe
467  * @selftest: selftest to run on boot (see trace_selftest.c)
468  * @print_headers: override the first lines that describe your columns
469  * @print_line: callback that prints a trace
470  * @set_flag: signals one of your private flags changed (trace_options file)
471  * @flags: your private flags
472  */
473 struct tracer {
474 	const char		*name;
475 	int			(*init)(struct trace_array *tr);
476 	void			(*reset)(struct trace_array *tr);
477 	void			(*start)(struct trace_array *tr);
478 	void			(*stop)(struct trace_array *tr);
479 	int			(*update_thresh)(struct trace_array *tr);
480 	void			(*open)(struct trace_iterator *iter);
481 	void			(*pipe_open)(struct trace_iterator *iter);
482 	void			(*close)(struct trace_iterator *iter);
483 	void			(*pipe_close)(struct trace_iterator *iter);
484 	ssize_t			(*read)(struct trace_iterator *iter,
485 					struct file *filp, char __user *ubuf,
486 					size_t cnt, loff_t *ppos);
487 	ssize_t			(*splice_read)(struct trace_iterator *iter,
488 					       struct file *filp,
489 					       loff_t *ppos,
490 					       struct pipe_inode_info *pipe,
491 					       size_t len,
492 					       unsigned int flags);
493 #ifdef CONFIG_FTRACE_STARTUP_TEST
494 	int			(*selftest)(struct tracer *trace,
495 					    struct trace_array *tr);
496 #endif
497 	void			(*print_header)(struct seq_file *m);
498 	enum print_line_t	(*print_line)(struct trace_iterator *iter);
499 	/* If you handled the flag setting, return 0 */
500 	int			(*set_flag)(struct trace_array *tr,
501 					    u32 old_flags, u32 bit, int set);
502 	/* Return 0 if OK with change, else return non-zero */
503 	int			(*flag_changed)(struct trace_array *tr,
504 						u32 mask, int set);
505 	struct tracer		*next;
506 	struct tracer_flags	*flags;
507 	int			enabled;
508 	int			ref;
509 	bool			print_max;
510 	bool			allow_instances;
511 #ifdef CONFIG_TRACER_MAX_TRACE
512 	bool			use_max_tr;
513 #endif
514 	/* True if tracer cannot be enabled in kernel param */
515 	bool			noboot;
516 };
517 
518 
519 /* Only current can touch trace_recursion */
520 
521 /*
522  * For function tracing recursion:
523  *  The order of these bits are important.
524  *
525  *  When function tracing occurs, the following steps are made:
526  *   If arch does not support a ftrace feature:
527  *    call internal function (uses INTERNAL bits) which calls...
528  *   If callback is registered to the "global" list, the list
529  *    function is called and recursion checks the GLOBAL bits.
530  *    then this function calls...
531  *   The function callback, which can use the FTRACE bits to
532  *    check for recursion.
533  *
534  * Now if the arch does not suppport a feature, and it calls
535  * the global list function which calls the ftrace callback
536  * all three of these steps will do a recursion protection.
537  * There's no reason to do one if the previous caller already
538  * did. The recursion that we are protecting against will
539  * go through the same steps again.
540  *
541  * To prevent the multiple recursion checks, if a recursion
542  * bit is set that is higher than the MAX bit of the current
543  * check, then we know that the check was made by the previous
544  * caller, and we can skip the current check.
545  */
546 enum {
547 	TRACE_BUFFER_BIT,
548 	TRACE_BUFFER_NMI_BIT,
549 	TRACE_BUFFER_IRQ_BIT,
550 	TRACE_BUFFER_SIRQ_BIT,
551 
552 	/* Start of function recursion bits */
553 	TRACE_FTRACE_BIT,
554 	TRACE_FTRACE_NMI_BIT,
555 	TRACE_FTRACE_IRQ_BIT,
556 	TRACE_FTRACE_SIRQ_BIT,
557 
558 	/* INTERNAL_BITs must be greater than FTRACE_BITs */
559 	TRACE_INTERNAL_BIT,
560 	TRACE_INTERNAL_NMI_BIT,
561 	TRACE_INTERNAL_IRQ_BIT,
562 	TRACE_INTERNAL_SIRQ_BIT,
563 
564 	TRACE_BRANCH_BIT,
565 /*
566  * Abuse of the trace_recursion.
567  * As we need a way to maintain state if we are tracing the function
568  * graph in irq because we want to trace a particular function that
569  * was called in irq context but we have irq tracing off. Since this
570  * can only be modified by current, we can reuse trace_recursion.
571  */
572 	TRACE_IRQ_BIT,
573 
574 	/* Set if the function is in the set_graph_function file */
575 	TRACE_GRAPH_BIT,
576 
577 	/*
578 	 * In the very unlikely case that an interrupt came in
579 	 * at a start of graph tracing, and we want to trace
580 	 * the function in that interrupt, the depth can be greater
581 	 * than zero, because of the preempted start of a previous
582 	 * trace. In an even more unlikely case, depth could be 2
583 	 * if a softirq interrupted the start of graph tracing,
584 	 * followed by an interrupt preempting a start of graph
585 	 * tracing in the softirq, and depth can even be 3
586 	 * if an NMI came in at the start of an interrupt function
587 	 * that preempted a softirq start of a function that
588 	 * preempted normal context!!!! Luckily, it can't be
589 	 * greater than 3, so the next two bits are a mask
590 	 * of what the depth is when we set TRACE_GRAPH_BIT
591 	 */
592 
593 	TRACE_GRAPH_DEPTH_START_BIT,
594 	TRACE_GRAPH_DEPTH_END_BIT,
595 
596 	/*
597 	 * To implement set_graph_notrace, if this bit is set, we ignore
598 	 * function graph tracing of called functions, until the return
599 	 * function is called to clear it.
600 	 */
601 	TRACE_GRAPH_NOTRACE_BIT,
602 };
603 
604 #define trace_recursion_set(bit)	do { (current)->trace_recursion |= (1<<(bit)); } while (0)
605 #define trace_recursion_clear(bit)	do { (current)->trace_recursion &= ~(1<<(bit)); } while (0)
606 #define trace_recursion_test(bit)	((current)->trace_recursion & (1<<(bit)))
607 
608 #define trace_recursion_depth() \
609 	(((current)->trace_recursion >> TRACE_GRAPH_DEPTH_START_BIT) & 3)
610 #define trace_recursion_set_depth(depth) \
611 	do {								\
612 		current->trace_recursion &=				\
613 			~(3 << TRACE_GRAPH_DEPTH_START_BIT);		\
614 		current->trace_recursion |=				\
615 			((depth) & 3) << TRACE_GRAPH_DEPTH_START_BIT;	\
616 	} while (0)
617 
618 #define TRACE_CONTEXT_BITS	4
619 
620 #define TRACE_FTRACE_START	TRACE_FTRACE_BIT
621 #define TRACE_FTRACE_MAX	((1 << (TRACE_FTRACE_START + TRACE_CONTEXT_BITS)) - 1)
622 
623 #define TRACE_LIST_START	TRACE_INTERNAL_BIT
624 #define TRACE_LIST_MAX		((1 << (TRACE_LIST_START + TRACE_CONTEXT_BITS)) - 1)
625 
626 #define TRACE_CONTEXT_MASK	TRACE_LIST_MAX
627 
628 static __always_inline int trace_get_context_bit(void)
629 {
630 	int bit;
631 
632 	if (in_interrupt()) {
633 		if (in_nmi())
634 			bit = 0;
635 
636 		else if (in_irq())
637 			bit = 1;
638 		else
639 			bit = 2;
640 	} else
641 		bit = 3;
642 
643 	return bit;
644 }
645 
646 static __always_inline int trace_test_and_set_recursion(int start, int max)
647 {
648 	unsigned int val = current->trace_recursion;
649 	int bit;
650 
651 	/* A previous recursion check was made */
652 	if ((val & TRACE_CONTEXT_MASK) > max)
653 		return 0;
654 
655 	bit = trace_get_context_bit() + start;
656 	if (unlikely(val & (1 << bit)))
657 		return -1;
658 
659 	val |= 1 << bit;
660 	current->trace_recursion = val;
661 	barrier();
662 
663 	return bit;
664 }
665 
666 static __always_inline void trace_clear_recursion(int bit)
667 {
668 	unsigned int val = current->trace_recursion;
669 
670 	if (!bit)
671 		return;
672 
673 	bit = 1 << bit;
674 	val &= ~bit;
675 
676 	barrier();
677 	current->trace_recursion = val;
678 }
679 
680 static inline struct ring_buffer_iter *
681 trace_buffer_iter(struct trace_iterator *iter, int cpu)
682 {
683 	return iter->buffer_iter ? iter->buffer_iter[cpu] : NULL;
684 }
685 
686 int tracer_init(struct tracer *t, struct trace_array *tr);
687 int tracing_is_enabled(void);
688 void tracing_reset_online_cpus(struct trace_buffer *buf);
689 void tracing_reset_current(int cpu);
690 void tracing_reset_all_online_cpus(void);
691 int tracing_open_generic(struct inode *inode, struct file *filp);
692 int tracing_open_generic_tr(struct inode *inode, struct file *filp);
693 bool tracing_is_disabled(void);
694 bool tracer_tracing_is_on(struct trace_array *tr);
695 void tracer_tracing_on(struct trace_array *tr);
696 void tracer_tracing_off(struct trace_array *tr);
697 struct dentry *trace_create_file(const char *name,
698 				 umode_t mode,
699 				 struct dentry *parent,
700 				 void *data,
701 				 const struct file_operations *fops);
702 
703 struct dentry *tracing_init_dentry(void);
704 
705 struct ring_buffer_event;
706 
707 struct ring_buffer_event *
708 trace_buffer_lock_reserve(struct ring_buffer *buffer,
709 			  int type,
710 			  unsigned long len,
711 			  unsigned long flags,
712 			  int pc);
713 
714 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
715 						struct trace_array_cpu *data);
716 
717 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
718 					  int *ent_cpu, u64 *ent_ts);
719 
720 void trace_buffer_unlock_commit_nostack(struct ring_buffer *buffer,
721 					struct ring_buffer_event *event);
722 
723 int trace_empty(struct trace_iterator *iter);
724 
725 void *trace_find_next_entry_inc(struct trace_iterator *iter);
726 
727 void trace_init_global_iter(struct trace_iterator *iter);
728 
729 void tracing_iter_reset(struct trace_iterator *iter, int cpu);
730 
731 unsigned long trace_total_entries_cpu(struct trace_array *tr, int cpu);
732 unsigned long trace_total_entries(struct trace_array *tr);
733 
734 void trace_function(struct trace_array *tr,
735 		    unsigned long ip,
736 		    unsigned long parent_ip,
737 		    unsigned long flags, int pc);
738 void trace_graph_function(struct trace_array *tr,
739 		    unsigned long ip,
740 		    unsigned long parent_ip,
741 		    unsigned long flags, int pc);
742 void trace_latency_header(struct seq_file *m);
743 void trace_default_header(struct seq_file *m);
744 void print_trace_header(struct seq_file *m, struct trace_iterator *iter);
745 int trace_empty(struct trace_iterator *iter);
746 
747 void trace_graph_return(struct ftrace_graph_ret *trace);
748 int trace_graph_entry(struct ftrace_graph_ent *trace);
749 void set_graph_array(struct trace_array *tr);
750 
751 void tracing_start_cmdline_record(void);
752 void tracing_stop_cmdline_record(void);
753 void tracing_start_tgid_record(void);
754 void tracing_stop_tgid_record(void);
755 
756 int register_tracer(struct tracer *type);
757 int is_tracing_stopped(void);
758 
759 loff_t tracing_lseek(struct file *file, loff_t offset, int whence);
760 
761 extern cpumask_var_t __read_mostly tracing_buffer_mask;
762 
763 #define for_each_tracing_cpu(cpu)	\
764 	for_each_cpu(cpu, tracing_buffer_mask)
765 
766 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
767 
768 extern unsigned long tracing_thresh;
769 
770 /* PID filtering */
771 
772 extern int pid_max;
773 
774 bool trace_find_filtered_pid(struct trace_pid_list *filtered_pids,
775 			     pid_t search_pid);
776 bool trace_ignore_this_task(struct trace_pid_list *filtered_pids,
777 			    struct task_struct *task);
778 void trace_filter_add_remove_task(struct trace_pid_list *pid_list,
779 				  struct task_struct *self,
780 				  struct task_struct *task);
781 void *trace_pid_next(struct trace_pid_list *pid_list, void *v, loff_t *pos);
782 void *trace_pid_start(struct trace_pid_list *pid_list, loff_t *pos);
783 int trace_pid_show(struct seq_file *m, void *v);
784 void trace_free_pid_list(struct trace_pid_list *pid_list);
785 int trace_pid_write(struct trace_pid_list *filtered_pids,
786 		    struct trace_pid_list **new_pid_list,
787 		    const char __user *ubuf, size_t cnt);
788 
789 #ifdef CONFIG_TRACER_MAX_TRACE
790 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu,
791 		   void *cond_data);
792 void update_max_tr_single(struct trace_array *tr,
793 			  struct task_struct *tsk, int cpu);
794 #endif /* CONFIG_TRACER_MAX_TRACE */
795 
796 #if (defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)) && \
797 	defined(CONFIG_FSNOTIFY)
798 
799 void latency_fsnotify(struct trace_array *tr);
800 
801 #else
802 
803 static void latency_fsnotify(struct trace_array *tr) { }
804 
805 #endif
806 
807 #ifdef CONFIG_STACKTRACE
808 void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
809 		   int pc);
810 #else
811 static inline void __trace_stack(struct trace_array *tr, unsigned long flags,
812 				 int skip, int pc)
813 {
814 }
815 #endif /* CONFIG_STACKTRACE */
816 
817 extern u64 ftrace_now(int cpu);
818 
819 extern void trace_find_cmdline(int pid, char comm[]);
820 extern int trace_find_tgid(int pid);
821 extern void trace_event_follow_fork(struct trace_array *tr, bool enable);
822 
823 #ifdef CONFIG_DYNAMIC_FTRACE
824 extern unsigned long ftrace_update_tot_cnt;
825 extern unsigned long ftrace_number_of_pages;
826 extern unsigned long ftrace_number_of_groups;
827 void ftrace_init_trace_array(struct trace_array *tr);
828 #else
829 static inline void ftrace_init_trace_array(struct trace_array *tr) { }
830 #endif
831 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
832 extern int DYN_FTRACE_TEST_NAME(void);
833 #define DYN_FTRACE_TEST_NAME2 trace_selftest_dynamic_test_func2
834 extern int DYN_FTRACE_TEST_NAME2(void);
835 
836 extern bool ring_buffer_expanded;
837 extern bool tracing_selftest_disabled;
838 
839 #ifdef CONFIG_FTRACE_STARTUP_TEST
840 extern int trace_selftest_startup_function(struct tracer *trace,
841 					   struct trace_array *tr);
842 extern int trace_selftest_startup_function_graph(struct tracer *trace,
843 						 struct trace_array *tr);
844 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
845 					  struct trace_array *tr);
846 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
847 					     struct trace_array *tr);
848 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
849 						 struct trace_array *tr);
850 extern int trace_selftest_startup_wakeup(struct tracer *trace,
851 					 struct trace_array *tr);
852 extern int trace_selftest_startup_nop(struct tracer *trace,
853 					 struct trace_array *tr);
854 extern int trace_selftest_startup_branch(struct tracer *trace,
855 					 struct trace_array *tr);
856 /*
857  * Tracer data references selftest functions that only occur
858  * on boot up. These can be __init functions. Thus, when selftests
859  * are enabled, then the tracers need to reference __init functions.
860  */
861 #define __tracer_data		__refdata
862 #else
863 /* Tracers are seldom changed. Optimize when selftests are disabled. */
864 #define __tracer_data		__read_mostly
865 #endif /* CONFIG_FTRACE_STARTUP_TEST */
866 
867 extern void *head_page(struct trace_array_cpu *data);
868 extern unsigned long long ns2usecs(u64 nsec);
869 extern int
870 trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
871 extern int
872 trace_vprintk(unsigned long ip, const char *fmt, va_list args);
873 extern int
874 trace_array_vprintk(struct trace_array *tr,
875 		    unsigned long ip, const char *fmt, va_list args);
876 int trace_array_printk(struct trace_array *tr,
877 		       unsigned long ip, const char *fmt, ...);
878 int trace_array_printk_buf(struct ring_buffer *buffer,
879 			   unsigned long ip, const char *fmt, ...);
880 void trace_printk_seq(struct trace_seq *s);
881 enum print_line_t print_trace_line(struct trace_iterator *iter);
882 
883 extern char trace_find_mark(unsigned long long duration);
884 
885 struct ftrace_hash;
886 
887 struct ftrace_mod_load {
888 	struct list_head	list;
889 	char			*func;
890 	char			*module;
891 	int			 enable;
892 };
893 
894 enum {
895 	FTRACE_HASH_FL_MOD	= (1 << 0),
896 };
897 
898 struct ftrace_hash {
899 	unsigned long		size_bits;
900 	struct hlist_head	*buckets;
901 	unsigned long		count;
902 	unsigned long		flags;
903 	struct rcu_head		rcu;
904 };
905 
906 struct ftrace_func_entry *
907 ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip);
908 
909 static __always_inline bool ftrace_hash_empty(struct ftrace_hash *hash)
910 {
911 	return !hash || !(hash->count || (hash->flags & FTRACE_HASH_FL_MOD));
912 }
913 
914 /* Standard output formatting function used for function return traces */
915 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
916 
917 /* Flag options */
918 #define TRACE_GRAPH_PRINT_OVERRUN       0x1
919 #define TRACE_GRAPH_PRINT_CPU           0x2
920 #define TRACE_GRAPH_PRINT_OVERHEAD      0x4
921 #define TRACE_GRAPH_PRINT_PROC          0x8
922 #define TRACE_GRAPH_PRINT_DURATION      0x10
923 #define TRACE_GRAPH_PRINT_ABS_TIME      0x20
924 #define TRACE_GRAPH_PRINT_REL_TIME      0x40
925 #define TRACE_GRAPH_PRINT_IRQS          0x80
926 #define TRACE_GRAPH_PRINT_TAIL          0x100
927 #define TRACE_GRAPH_SLEEP_TIME          0x200
928 #define TRACE_GRAPH_GRAPH_TIME          0x400
929 #define TRACE_GRAPH_PRINT_FILL_SHIFT	28
930 #define TRACE_GRAPH_PRINT_FILL_MASK	(0x3 << TRACE_GRAPH_PRINT_FILL_SHIFT)
931 
932 extern void ftrace_graph_sleep_time_control(bool enable);
933 
934 #ifdef CONFIG_FUNCTION_PROFILER
935 extern void ftrace_graph_graph_time_control(bool enable);
936 #else
937 static inline void ftrace_graph_graph_time_control(bool enable) { }
938 #endif
939 
940 extern enum print_line_t
941 print_graph_function_flags(struct trace_iterator *iter, u32 flags);
942 extern void print_graph_headers_flags(struct seq_file *s, u32 flags);
943 extern void
944 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
945 extern void graph_trace_open(struct trace_iterator *iter);
946 extern void graph_trace_close(struct trace_iterator *iter);
947 extern int __trace_graph_entry(struct trace_array *tr,
948 			       struct ftrace_graph_ent *trace,
949 			       unsigned long flags, int pc);
950 extern void __trace_graph_return(struct trace_array *tr,
951 				 struct ftrace_graph_ret *trace,
952 				 unsigned long flags, int pc);
953 
954 #ifdef CONFIG_DYNAMIC_FTRACE
955 extern struct ftrace_hash *ftrace_graph_hash;
956 extern struct ftrace_hash *ftrace_graph_notrace_hash;
957 
958 static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace)
959 {
960 	unsigned long addr = trace->func;
961 	int ret = 0;
962 
963 	preempt_disable_notrace();
964 
965 	if (ftrace_hash_empty(ftrace_graph_hash)) {
966 		ret = 1;
967 		goto out;
968 	}
969 
970 	if (ftrace_lookup_ip(ftrace_graph_hash, addr)) {
971 
972 		/*
973 		 * This needs to be cleared on the return functions
974 		 * when the depth is zero.
975 		 */
976 		trace_recursion_set(TRACE_GRAPH_BIT);
977 		trace_recursion_set_depth(trace->depth);
978 
979 		/*
980 		 * If no irqs are to be traced, but a set_graph_function
981 		 * is set, and called by an interrupt handler, we still
982 		 * want to trace it.
983 		 */
984 		if (in_irq())
985 			trace_recursion_set(TRACE_IRQ_BIT);
986 		else
987 			trace_recursion_clear(TRACE_IRQ_BIT);
988 		ret = 1;
989 	}
990 
991 out:
992 	preempt_enable_notrace();
993 	return ret;
994 }
995 
996 static inline void ftrace_graph_addr_finish(struct ftrace_graph_ret *trace)
997 {
998 	if (trace_recursion_test(TRACE_GRAPH_BIT) &&
999 	    trace->depth == trace_recursion_depth())
1000 		trace_recursion_clear(TRACE_GRAPH_BIT);
1001 }
1002 
1003 static inline int ftrace_graph_notrace_addr(unsigned long addr)
1004 {
1005 	int ret = 0;
1006 
1007 	preempt_disable_notrace();
1008 
1009 	if (ftrace_lookup_ip(ftrace_graph_notrace_hash, addr))
1010 		ret = 1;
1011 
1012 	preempt_enable_notrace();
1013 	return ret;
1014 }
1015 #else
1016 static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace)
1017 {
1018 	return 1;
1019 }
1020 
1021 static inline int ftrace_graph_notrace_addr(unsigned long addr)
1022 {
1023 	return 0;
1024 }
1025 static inline void ftrace_graph_addr_finish(struct ftrace_graph_ret *trace)
1026 { }
1027 #endif /* CONFIG_DYNAMIC_FTRACE */
1028 
1029 extern unsigned int fgraph_max_depth;
1030 
1031 static inline bool ftrace_graph_ignore_func(struct ftrace_graph_ent *trace)
1032 {
1033 	/* trace it when it is-nested-in or is a function enabled. */
1034 	return !(trace_recursion_test(TRACE_GRAPH_BIT) ||
1035 		 ftrace_graph_addr(trace)) ||
1036 		(trace->depth < 0) ||
1037 		(fgraph_max_depth && trace->depth >= fgraph_max_depth);
1038 }
1039 
1040 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
1041 static inline enum print_line_t
1042 print_graph_function_flags(struct trace_iterator *iter, u32 flags)
1043 {
1044 	return TRACE_TYPE_UNHANDLED;
1045 }
1046 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
1047 
1048 extern struct list_head ftrace_pids;
1049 
1050 #ifdef CONFIG_FUNCTION_TRACER
1051 struct ftrace_func_command {
1052 	struct list_head	list;
1053 	char			*name;
1054 	int			(*func)(struct trace_array *tr,
1055 					struct ftrace_hash *hash,
1056 					char *func, char *cmd,
1057 					char *params, int enable);
1058 };
1059 extern bool ftrace_filter_param __initdata;
1060 static inline int ftrace_trace_task(struct trace_array *tr)
1061 {
1062 	return !this_cpu_read(tr->trace_buffer.data->ftrace_ignore_pid);
1063 }
1064 extern int ftrace_is_dead(void);
1065 int ftrace_create_function_files(struct trace_array *tr,
1066 				 struct dentry *parent);
1067 void ftrace_destroy_function_files(struct trace_array *tr);
1068 void ftrace_init_global_array_ops(struct trace_array *tr);
1069 void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func);
1070 void ftrace_reset_array_ops(struct trace_array *tr);
1071 void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer);
1072 void ftrace_init_tracefs_toplevel(struct trace_array *tr,
1073 				  struct dentry *d_tracer);
1074 void ftrace_clear_pids(struct trace_array *tr);
1075 int init_function_trace(void);
1076 void ftrace_pid_follow_fork(struct trace_array *tr, bool enable);
1077 #else
1078 static inline int ftrace_trace_task(struct trace_array *tr)
1079 {
1080 	return 1;
1081 }
1082 static inline int ftrace_is_dead(void) { return 0; }
1083 static inline int
1084 ftrace_create_function_files(struct trace_array *tr,
1085 			     struct dentry *parent)
1086 {
1087 	return 0;
1088 }
1089 static inline void ftrace_destroy_function_files(struct trace_array *tr) { }
1090 static inline __init void
1091 ftrace_init_global_array_ops(struct trace_array *tr) { }
1092 static inline void ftrace_reset_array_ops(struct trace_array *tr) { }
1093 static inline void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d) { }
1094 static inline void ftrace_init_tracefs_toplevel(struct trace_array *tr, struct dentry *d) { }
1095 static inline void ftrace_clear_pids(struct trace_array *tr) { }
1096 static inline int init_function_trace(void) { return 0; }
1097 static inline void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) { }
1098 /* ftace_func_t type is not defined, use macro instead of static inline */
1099 #define ftrace_init_array_ops(tr, func) do { } while (0)
1100 #endif /* CONFIG_FUNCTION_TRACER */
1101 
1102 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
1103 
1104 struct ftrace_probe_ops {
1105 	void			(*func)(unsigned long ip,
1106 					unsigned long parent_ip,
1107 					struct trace_array *tr,
1108 					struct ftrace_probe_ops *ops,
1109 					void *data);
1110 	int			(*init)(struct ftrace_probe_ops *ops,
1111 					struct trace_array *tr,
1112 					unsigned long ip, void *init_data,
1113 					void **data);
1114 	void			(*free)(struct ftrace_probe_ops *ops,
1115 					struct trace_array *tr,
1116 					unsigned long ip, void *data);
1117 	int			(*print)(struct seq_file *m,
1118 					 unsigned long ip,
1119 					 struct ftrace_probe_ops *ops,
1120 					 void *data);
1121 };
1122 
1123 struct ftrace_func_mapper;
1124 typedef int (*ftrace_mapper_func)(void *data);
1125 
1126 struct ftrace_func_mapper *allocate_ftrace_func_mapper(void);
1127 void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
1128 					   unsigned long ip);
1129 int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
1130 			       unsigned long ip, void *data);
1131 void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
1132 				   unsigned long ip);
1133 void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
1134 			     ftrace_mapper_func free_func);
1135 
1136 extern int
1137 register_ftrace_function_probe(char *glob, struct trace_array *tr,
1138 			       struct ftrace_probe_ops *ops, void *data);
1139 extern int
1140 unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
1141 				      struct ftrace_probe_ops *ops);
1142 extern void clear_ftrace_function_probes(struct trace_array *tr);
1143 
1144 int register_ftrace_command(struct ftrace_func_command *cmd);
1145 int unregister_ftrace_command(struct ftrace_func_command *cmd);
1146 
1147 void ftrace_create_filter_files(struct ftrace_ops *ops,
1148 				struct dentry *parent);
1149 void ftrace_destroy_filter_files(struct ftrace_ops *ops);
1150 #else
1151 struct ftrace_func_command;
1152 
1153 static inline __init int register_ftrace_command(struct ftrace_func_command *cmd)
1154 {
1155 	return -EINVAL;
1156 }
1157 static inline __init int unregister_ftrace_command(char *cmd_name)
1158 {
1159 	return -EINVAL;
1160 }
1161 static inline void clear_ftrace_function_probes(struct trace_array *tr)
1162 {
1163 }
1164 
1165 /*
1166  * The ops parameter passed in is usually undefined.
1167  * This must be a macro.
1168  */
1169 #define ftrace_create_filter_files(ops, parent) do { } while (0)
1170 #define ftrace_destroy_filter_files(ops) do { } while (0)
1171 #endif /* CONFIG_FUNCTION_TRACER && CONFIG_DYNAMIC_FTRACE */
1172 
1173 bool ftrace_event_is_function(struct trace_event_call *call);
1174 
1175 /*
1176  * struct trace_parser - servers for reading the user input separated by spaces
1177  * @cont: set if the input is not complete - no final space char was found
1178  * @buffer: holds the parsed user input
1179  * @idx: user input length
1180  * @size: buffer size
1181  */
1182 struct trace_parser {
1183 	bool		cont;
1184 	char		*buffer;
1185 	unsigned	idx;
1186 	unsigned	size;
1187 };
1188 
1189 static inline bool trace_parser_loaded(struct trace_parser *parser)
1190 {
1191 	return (parser->idx != 0);
1192 }
1193 
1194 static inline bool trace_parser_cont(struct trace_parser *parser)
1195 {
1196 	return parser->cont;
1197 }
1198 
1199 static inline void trace_parser_clear(struct trace_parser *parser)
1200 {
1201 	parser->cont = false;
1202 	parser->idx = 0;
1203 }
1204 
1205 extern int trace_parser_get_init(struct trace_parser *parser, int size);
1206 extern void trace_parser_put(struct trace_parser *parser);
1207 extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
1208 	size_t cnt, loff_t *ppos);
1209 
1210 /*
1211  * Only create function graph options if function graph is configured.
1212  */
1213 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1214 # define FGRAPH_FLAGS						\
1215 		C(DISPLAY_GRAPH,	"display-graph"),
1216 #else
1217 # define FGRAPH_FLAGS
1218 #endif
1219 
1220 #ifdef CONFIG_BRANCH_TRACER
1221 # define BRANCH_FLAGS					\
1222 		C(BRANCH,		"branch"),
1223 #else
1224 # define BRANCH_FLAGS
1225 #endif
1226 
1227 #ifdef CONFIG_FUNCTION_TRACER
1228 # define FUNCTION_FLAGS						\
1229 		C(FUNCTION,		"function-trace"),	\
1230 		C(FUNC_FORK,		"function-fork"),
1231 # define FUNCTION_DEFAULT_FLAGS		TRACE_ITER_FUNCTION
1232 #else
1233 # define FUNCTION_FLAGS
1234 # define FUNCTION_DEFAULT_FLAGS		0UL
1235 # define TRACE_ITER_FUNC_FORK		0UL
1236 #endif
1237 
1238 #ifdef CONFIG_STACKTRACE
1239 # define STACK_FLAGS				\
1240 		C(STACKTRACE,		"stacktrace"),
1241 #else
1242 # define STACK_FLAGS
1243 #endif
1244 
1245 /*
1246  * trace_iterator_flags is an enumeration that defines bit
1247  * positions into trace_flags that controls the output.
1248  *
1249  * NOTE: These bits must match the trace_options array in
1250  *       trace.c (this macro guarantees it).
1251  */
1252 #define TRACE_FLAGS						\
1253 		C(PRINT_PARENT,		"print-parent"),	\
1254 		C(SYM_OFFSET,		"sym-offset"),		\
1255 		C(SYM_ADDR,		"sym-addr"),		\
1256 		C(VERBOSE,		"verbose"),		\
1257 		C(RAW,			"raw"),			\
1258 		C(HEX,			"hex"),			\
1259 		C(BIN,			"bin"),			\
1260 		C(BLOCK,		"block"),		\
1261 		C(PRINTK,		"trace_printk"),	\
1262 		C(ANNOTATE,		"annotate"),		\
1263 		C(USERSTACKTRACE,	"userstacktrace"),	\
1264 		C(SYM_USEROBJ,		"sym-userobj"),		\
1265 		C(PRINTK_MSGONLY,	"printk-msg-only"),	\
1266 		C(CONTEXT_INFO,		"context-info"),   /* Print pid/cpu/time */ \
1267 		C(LATENCY_FMT,		"latency-format"),	\
1268 		C(RECORD_CMD,		"record-cmd"),		\
1269 		C(RECORD_TGID,		"record-tgid"),		\
1270 		C(OVERWRITE,		"overwrite"),		\
1271 		C(STOP_ON_FREE,		"disable_on_free"),	\
1272 		C(IRQ_INFO,		"irq-info"),		\
1273 		C(MARKERS,		"markers"),		\
1274 		C(EVENT_FORK,		"event-fork"),		\
1275 		FUNCTION_FLAGS					\
1276 		FGRAPH_FLAGS					\
1277 		STACK_FLAGS					\
1278 		BRANCH_FLAGS
1279 
1280 /*
1281  * By defining C, we can make TRACE_FLAGS a list of bit names
1282  * that will define the bits for the flag masks.
1283  */
1284 #undef C
1285 #define C(a, b) TRACE_ITER_##a##_BIT
1286 
1287 enum trace_iterator_bits {
1288 	TRACE_FLAGS
1289 	/* Make sure we don't go more than we have bits for */
1290 	TRACE_ITER_LAST_BIT
1291 };
1292 
1293 /*
1294  * By redefining C, we can make TRACE_FLAGS a list of masks that
1295  * use the bits as defined above.
1296  */
1297 #undef C
1298 #define C(a, b) TRACE_ITER_##a = (1 << TRACE_ITER_##a##_BIT)
1299 
1300 enum trace_iterator_flags { TRACE_FLAGS };
1301 
1302 /*
1303  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
1304  * control the output of kernel symbols.
1305  */
1306 #define TRACE_ITER_SYM_MASK \
1307 	(TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
1308 
1309 extern struct tracer nop_trace;
1310 
1311 #ifdef CONFIG_BRANCH_TRACER
1312 extern int enable_branch_tracing(struct trace_array *tr);
1313 extern void disable_branch_tracing(void);
1314 static inline int trace_branch_enable(struct trace_array *tr)
1315 {
1316 	if (tr->trace_flags & TRACE_ITER_BRANCH)
1317 		return enable_branch_tracing(tr);
1318 	return 0;
1319 }
1320 static inline void trace_branch_disable(void)
1321 {
1322 	/* due to races, always disable */
1323 	disable_branch_tracing();
1324 }
1325 #else
1326 static inline int trace_branch_enable(struct trace_array *tr)
1327 {
1328 	return 0;
1329 }
1330 static inline void trace_branch_disable(void)
1331 {
1332 }
1333 #endif /* CONFIG_BRANCH_TRACER */
1334 
1335 /* set ring buffers to default size if not already done so */
1336 int tracing_update_buffers(void);
1337 
1338 struct ftrace_event_field {
1339 	struct list_head	link;
1340 	const char		*name;
1341 	const char		*type;
1342 	int			filter_type;
1343 	int			offset;
1344 	int			size;
1345 	int			is_signed;
1346 };
1347 
1348 struct prog_entry;
1349 
1350 struct event_filter {
1351 	struct prog_entry __rcu	*prog;
1352 	char			*filter_string;
1353 };
1354 
1355 struct event_subsystem {
1356 	struct list_head	list;
1357 	const char		*name;
1358 	struct event_filter	*filter;
1359 	int			ref_count;
1360 };
1361 
1362 struct trace_subsystem_dir {
1363 	struct list_head		list;
1364 	struct event_subsystem		*subsystem;
1365 	struct trace_array		*tr;
1366 	struct dentry			*entry;
1367 	int				ref_count;
1368 	int				nr_events;
1369 };
1370 
1371 extern int call_filter_check_discard(struct trace_event_call *call, void *rec,
1372 				     struct ring_buffer *buffer,
1373 				     struct ring_buffer_event *event);
1374 
1375 void trace_buffer_unlock_commit_regs(struct trace_array *tr,
1376 				     struct ring_buffer *buffer,
1377 				     struct ring_buffer_event *event,
1378 				     unsigned long flags, int pc,
1379 				     struct pt_regs *regs);
1380 
1381 static inline void trace_buffer_unlock_commit(struct trace_array *tr,
1382 					      struct ring_buffer *buffer,
1383 					      struct ring_buffer_event *event,
1384 					      unsigned long flags, int pc)
1385 {
1386 	trace_buffer_unlock_commit_regs(tr, buffer, event, flags, pc, NULL);
1387 }
1388 
1389 DECLARE_PER_CPU(struct ring_buffer_event *, trace_buffered_event);
1390 DECLARE_PER_CPU(int, trace_buffered_event_cnt);
1391 void trace_buffered_event_disable(void);
1392 void trace_buffered_event_enable(void);
1393 
1394 static inline void
1395 __trace_event_discard_commit(struct ring_buffer *buffer,
1396 			     struct ring_buffer_event *event)
1397 {
1398 	if (this_cpu_read(trace_buffered_event) == event) {
1399 		/* Simply release the temp buffer */
1400 		this_cpu_dec(trace_buffered_event_cnt);
1401 		return;
1402 	}
1403 	ring_buffer_discard_commit(buffer, event);
1404 }
1405 
1406 /*
1407  * Helper function for event_trigger_unlock_commit{_regs}().
1408  * If there are event triggers attached to this event that requires
1409  * filtering against its fields, then they wil be called as the
1410  * entry already holds the field information of the current event.
1411  *
1412  * It also checks if the event should be discarded or not.
1413  * It is to be discarded if the event is soft disabled and the
1414  * event was only recorded to process triggers, or if the event
1415  * filter is active and this event did not match the filters.
1416  *
1417  * Returns true if the event is discarded, false otherwise.
1418  */
1419 static inline bool
1420 __event_trigger_test_discard(struct trace_event_file *file,
1421 			     struct ring_buffer *buffer,
1422 			     struct ring_buffer_event *event,
1423 			     void *entry,
1424 			     enum event_trigger_type *tt)
1425 {
1426 	unsigned long eflags = file->flags;
1427 
1428 	if (eflags & EVENT_FILE_FL_TRIGGER_COND)
1429 		*tt = event_triggers_call(file, entry, event);
1430 
1431 	if (test_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags) ||
1432 	    (unlikely(file->flags & EVENT_FILE_FL_FILTERED) &&
1433 	     !filter_match_preds(file->filter, entry))) {
1434 		__trace_event_discard_commit(buffer, event);
1435 		return true;
1436 	}
1437 
1438 	return false;
1439 }
1440 
1441 /**
1442  * event_trigger_unlock_commit - handle triggers and finish event commit
1443  * @file: The file pointer assoctiated to the event
1444  * @buffer: The ring buffer that the event is being written to
1445  * @event: The event meta data in the ring buffer
1446  * @entry: The event itself
1447  * @irq_flags: The state of the interrupts at the start of the event
1448  * @pc: The state of the preempt count at the start of the event.
1449  *
1450  * This is a helper function to handle triggers that require data
1451  * from the event itself. It also tests the event against filters and
1452  * if the event is soft disabled and should be discarded.
1453  */
1454 static inline void
1455 event_trigger_unlock_commit(struct trace_event_file *file,
1456 			    struct ring_buffer *buffer,
1457 			    struct ring_buffer_event *event,
1458 			    void *entry, unsigned long irq_flags, int pc)
1459 {
1460 	enum event_trigger_type tt = ETT_NONE;
1461 
1462 	if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1463 		trace_buffer_unlock_commit(file->tr, buffer, event, irq_flags, pc);
1464 
1465 	if (tt)
1466 		event_triggers_post_call(file, tt);
1467 }
1468 
1469 /**
1470  * event_trigger_unlock_commit_regs - handle triggers and finish event commit
1471  * @file: The file pointer assoctiated to the event
1472  * @buffer: The ring buffer that the event is being written to
1473  * @event: The event meta data in the ring buffer
1474  * @entry: The event itself
1475  * @irq_flags: The state of the interrupts at the start of the event
1476  * @pc: The state of the preempt count at the start of the event.
1477  *
1478  * This is a helper function to handle triggers that require data
1479  * from the event itself. It also tests the event against filters and
1480  * if the event is soft disabled and should be discarded.
1481  *
1482  * Same as event_trigger_unlock_commit() but calls
1483  * trace_buffer_unlock_commit_regs() instead of trace_buffer_unlock_commit().
1484  */
1485 static inline void
1486 event_trigger_unlock_commit_regs(struct trace_event_file *file,
1487 				 struct ring_buffer *buffer,
1488 				 struct ring_buffer_event *event,
1489 				 void *entry, unsigned long irq_flags, int pc,
1490 				 struct pt_regs *regs)
1491 {
1492 	enum event_trigger_type tt = ETT_NONE;
1493 
1494 	if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1495 		trace_buffer_unlock_commit_regs(file->tr, buffer, event,
1496 						irq_flags, pc, regs);
1497 
1498 	if (tt)
1499 		event_triggers_post_call(file, tt);
1500 }
1501 
1502 #define FILTER_PRED_INVALID	((unsigned short)-1)
1503 #define FILTER_PRED_IS_RIGHT	(1 << 15)
1504 #define FILTER_PRED_FOLD	(1 << 15)
1505 
1506 /*
1507  * The max preds is the size of unsigned short with
1508  * two flags at the MSBs. One bit is used for both the IS_RIGHT
1509  * and FOLD flags. The other is reserved.
1510  *
1511  * 2^14 preds is way more than enough.
1512  */
1513 #define MAX_FILTER_PRED		16384
1514 
1515 struct filter_pred;
1516 struct regex;
1517 
1518 typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event);
1519 
1520 typedef int (*regex_match_func)(char *str, struct regex *r, int len);
1521 
1522 enum regex_type {
1523 	MATCH_FULL = 0,
1524 	MATCH_FRONT_ONLY,
1525 	MATCH_MIDDLE_ONLY,
1526 	MATCH_END_ONLY,
1527 	MATCH_GLOB,
1528 	MATCH_INDEX,
1529 };
1530 
1531 struct regex {
1532 	char			pattern[MAX_FILTER_STR_VAL];
1533 	int			len;
1534 	int			field_len;
1535 	regex_match_func	match;
1536 };
1537 
1538 struct filter_pred {
1539 	filter_pred_fn_t 	fn;
1540 	u64 			val;
1541 	struct regex		regex;
1542 	unsigned short		*ops;
1543 	struct ftrace_event_field *field;
1544 	int 			offset;
1545 	int			not;
1546 	int 			op;
1547 };
1548 
1549 static inline bool is_string_field(struct ftrace_event_field *field)
1550 {
1551 	return field->filter_type == FILTER_DYN_STRING ||
1552 	       field->filter_type == FILTER_STATIC_STRING ||
1553 	       field->filter_type == FILTER_PTR_STRING ||
1554 	       field->filter_type == FILTER_COMM;
1555 }
1556 
1557 static inline bool is_function_field(struct ftrace_event_field *field)
1558 {
1559 	return field->filter_type == FILTER_TRACE_FN;
1560 }
1561 
1562 extern enum regex_type
1563 filter_parse_regex(char *buff, int len, char **search, int *not);
1564 extern void print_event_filter(struct trace_event_file *file,
1565 			       struct trace_seq *s);
1566 extern int apply_event_filter(struct trace_event_file *file,
1567 			      char *filter_string);
1568 extern int apply_subsystem_event_filter(struct trace_subsystem_dir *dir,
1569 					char *filter_string);
1570 extern void print_subsystem_event_filter(struct event_subsystem *system,
1571 					 struct trace_seq *s);
1572 extern int filter_assign_type(const char *type);
1573 extern int create_event_filter(struct trace_array *tr,
1574 			       struct trace_event_call *call,
1575 			       char *filter_str, bool set_str,
1576 			       struct event_filter **filterp);
1577 extern void free_event_filter(struct event_filter *filter);
1578 
1579 struct ftrace_event_field *
1580 trace_find_event_field(struct trace_event_call *call, char *name);
1581 
1582 extern void trace_event_enable_cmd_record(bool enable);
1583 extern void trace_event_enable_tgid_record(bool enable);
1584 
1585 extern int event_trace_init(void);
1586 extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
1587 extern int event_trace_del_tracer(struct trace_array *tr);
1588 
1589 extern struct trace_event_file *__find_event_file(struct trace_array *tr,
1590 						  const char *system,
1591 						  const char *event);
1592 extern struct trace_event_file *find_event_file(struct trace_array *tr,
1593 						const char *system,
1594 						const char *event);
1595 
1596 static inline void *event_file_data(struct file *filp)
1597 {
1598 	return READ_ONCE(file_inode(filp)->i_private);
1599 }
1600 
1601 extern struct mutex event_mutex;
1602 extern struct list_head ftrace_events;
1603 
1604 extern const struct file_operations event_trigger_fops;
1605 extern const struct file_operations event_hist_fops;
1606 
1607 #ifdef CONFIG_HIST_TRIGGERS
1608 extern int register_trigger_hist_cmd(void);
1609 extern int register_trigger_hist_enable_disable_cmds(void);
1610 #else
1611 static inline int register_trigger_hist_cmd(void) { return 0; }
1612 static inline int register_trigger_hist_enable_disable_cmds(void) { return 0; }
1613 #endif
1614 
1615 extern int register_trigger_cmds(void);
1616 extern void clear_event_triggers(struct trace_array *tr);
1617 
1618 struct event_trigger_data {
1619 	unsigned long			count;
1620 	int				ref;
1621 	struct event_trigger_ops	*ops;
1622 	struct event_command		*cmd_ops;
1623 	struct event_filter __rcu	*filter;
1624 	char				*filter_str;
1625 	void				*private_data;
1626 	bool				paused;
1627 	bool				paused_tmp;
1628 	struct list_head		list;
1629 	char				*name;
1630 	struct list_head		named_list;
1631 	struct event_trigger_data	*named_data;
1632 };
1633 
1634 /* Avoid typos */
1635 #define ENABLE_EVENT_STR	"enable_event"
1636 #define DISABLE_EVENT_STR	"disable_event"
1637 #define ENABLE_HIST_STR		"enable_hist"
1638 #define DISABLE_HIST_STR	"disable_hist"
1639 
1640 struct enable_trigger_data {
1641 	struct trace_event_file		*file;
1642 	bool				enable;
1643 	bool				hist;
1644 };
1645 
1646 extern int event_enable_trigger_print(struct seq_file *m,
1647 				      struct event_trigger_ops *ops,
1648 				      struct event_trigger_data *data);
1649 extern void event_enable_trigger_free(struct event_trigger_ops *ops,
1650 				      struct event_trigger_data *data);
1651 extern int event_enable_trigger_func(struct event_command *cmd_ops,
1652 				     struct trace_event_file *file,
1653 				     char *glob, char *cmd, char *param);
1654 extern int event_enable_register_trigger(char *glob,
1655 					 struct event_trigger_ops *ops,
1656 					 struct event_trigger_data *data,
1657 					 struct trace_event_file *file);
1658 extern void event_enable_unregister_trigger(char *glob,
1659 					    struct event_trigger_ops *ops,
1660 					    struct event_trigger_data *test,
1661 					    struct trace_event_file *file);
1662 extern void trigger_data_free(struct event_trigger_data *data);
1663 extern int event_trigger_init(struct event_trigger_ops *ops,
1664 			      struct event_trigger_data *data);
1665 extern int trace_event_trigger_enable_disable(struct trace_event_file *file,
1666 					      int trigger_enable);
1667 extern void update_cond_flag(struct trace_event_file *file);
1668 extern int set_trigger_filter(char *filter_str,
1669 			      struct event_trigger_data *trigger_data,
1670 			      struct trace_event_file *file);
1671 extern struct event_trigger_data *find_named_trigger(const char *name);
1672 extern bool is_named_trigger(struct event_trigger_data *test);
1673 extern int save_named_trigger(const char *name,
1674 			      struct event_trigger_data *data);
1675 extern void del_named_trigger(struct event_trigger_data *data);
1676 extern void pause_named_trigger(struct event_trigger_data *data);
1677 extern void unpause_named_trigger(struct event_trigger_data *data);
1678 extern void set_named_trigger_data(struct event_trigger_data *data,
1679 				   struct event_trigger_data *named_data);
1680 extern struct event_trigger_data *
1681 get_named_trigger_data(struct event_trigger_data *data);
1682 extern int register_event_command(struct event_command *cmd);
1683 extern int unregister_event_command(struct event_command *cmd);
1684 extern int register_trigger_hist_enable_disable_cmds(void);
1685 
1686 /**
1687  * struct event_trigger_ops - callbacks for trace event triggers
1688  *
1689  * The methods in this structure provide per-event trigger hooks for
1690  * various trigger operations.
1691  *
1692  * All the methods below, except for @init() and @free(), must be
1693  * implemented.
1694  *
1695  * @func: The trigger 'probe' function called when the triggering
1696  *	event occurs.  The data passed into this callback is the data
1697  *	that was supplied to the event_command @reg() function that
1698  *	registered the trigger (see struct event_command) along with
1699  *	the trace record, rec.
1700  *
1701  * @init: An optional initialization function called for the trigger
1702  *	when the trigger is registered (via the event_command reg()
1703  *	function).  This can be used to perform per-trigger
1704  *	initialization such as incrementing a per-trigger reference
1705  *	count, for instance.  This is usually implemented by the
1706  *	generic utility function @event_trigger_init() (see
1707  *	trace_event_triggers.c).
1708  *
1709  * @free: An optional de-initialization function called for the
1710  *	trigger when the trigger is unregistered (via the
1711  *	event_command @reg() function).  This can be used to perform
1712  *	per-trigger de-initialization such as decrementing a
1713  *	per-trigger reference count and freeing corresponding trigger
1714  *	data, for instance.  This is usually implemented by the
1715  *	generic utility function @event_trigger_free() (see
1716  *	trace_event_triggers.c).
1717  *
1718  * @print: The callback function invoked to have the trigger print
1719  *	itself.  This is usually implemented by a wrapper function
1720  *	that calls the generic utility function @event_trigger_print()
1721  *	(see trace_event_triggers.c).
1722  */
1723 struct event_trigger_ops {
1724 	void			(*func)(struct event_trigger_data *data,
1725 					void *rec,
1726 					struct ring_buffer_event *rbe);
1727 	int			(*init)(struct event_trigger_ops *ops,
1728 					struct event_trigger_data *data);
1729 	void			(*free)(struct event_trigger_ops *ops,
1730 					struct event_trigger_data *data);
1731 	int			(*print)(struct seq_file *m,
1732 					 struct event_trigger_ops *ops,
1733 					 struct event_trigger_data *data);
1734 };
1735 
1736 /**
1737  * struct event_command - callbacks and data members for event commands
1738  *
1739  * Event commands are invoked by users by writing the command name
1740  * into the 'trigger' file associated with a trace event.  The
1741  * parameters associated with a specific invocation of an event
1742  * command are used to create an event trigger instance, which is
1743  * added to the list of trigger instances associated with that trace
1744  * event.  When the event is hit, the set of triggers associated with
1745  * that event is invoked.
1746  *
1747  * The data members in this structure provide per-event command data
1748  * for various event commands.
1749  *
1750  * All the data members below, except for @post_trigger, must be set
1751  * for each event command.
1752  *
1753  * @name: The unique name that identifies the event command.  This is
1754  *	the name used when setting triggers via trigger files.
1755  *
1756  * @trigger_type: A unique id that identifies the event command
1757  *	'type'.  This value has two purposes, the first to ensure that
1758  *	only one trigger of the same type can be set at a given time
1759  *	for a particular event e.g. it doesn't make sense to have both
1760  *	a traceon and traceoff trigger attached to a single event at
1761  *	the same time, so traceon and traceoff have the same type
1762  *	though they have different names.  The @trigger_type value is
1763  *	also used as a bit value for deferring the actual trigger
1764  *	action until after the current event is finished.  Some
1765  *	commands need to do this if they themselves log to the trace
1766  *	buffer (see the @post_trigger() member below).  @trigger_type
1767  *	values are defined by adding new values to the trigger_type
1768  *	enum in include/linux/trace_events.h.
1769  *
1770  * @flags: See the enum event_command_flags below.
1771  *
1772  * All the methods below, except for @set_filter() and @unreg_all(),
1773  * must be implemented.
1774  *
1775  * @func: The callback function responsible for parsing and
1776  *	registering the trigger written to the 'trigger' file by the
1777  *	user.  It allocates the trigger instance and registers it with
1778  *	the appropriate trace event.  It makes use of the other
1779  *	event_command callback functions to orchestrate this, and is
1780  *	usually implemented by the generic utility function
1781  *	@event_trigger_callback() (see trace_event_triggers.c).
1782  *
1783  * @reg: Adds the trigger to the list of triggers associated with the
1784  *	event, and enables the event trigger itself, after
1785  *	initializing it (via the event_trigger_ops @init() function).
1786  *	This is also where commands can use the @trigger_type value to
1787  *	make the decision as to whether or not multiple instances of
1788  *	the trigger should be allowed.  This is usually implemented by
1789  *	the generic utility function @register_trigger() (see
1790  *	trace_event_triggers.c).
1791  *
1792  * @unreg: Removes the trigger from the list of triggers associated
1793  *	with the event, and disables the event trigger itself, after
1794  *	initializing it (via the event_trigger_ops @free() function).
1795  *	This is usually implemented by the generic utility function
1796  *	@unregister_trigger() (see trace_event_triggers.c).
1797  *
1798  * @unreg_all: An optional function called to remove all the triggers
1799  *	from the list of triggers associated with the event.  Called
1800  *	when a trigger file is opened in truncate mode.
1801  *
1802  * @set_filter: An optional function called to parse and set a filter
1803  *	for the trigger.  If no @set_filter() method is set for the
1804  *	event command, filters set by the user for the command will be
1805  *	ignored.  This is usually implemented by the generic utility
1806  *	function @set_trigger_filter() (see trace_event_triggers.c).
1807  *
1808  * @get_trigger_ops: The callback function invoked to retrieve the
1809  *	event_trigger_ops implementation associated with the command.
1810  */
1811 struct event_command {
1812 	struct list_head	list;
1813 	char			*name;
1814 	enum event_trigger_type	trigger_type;
1815 	int			flags;
1816 	int			(*func)(struct event_command *cmd_ops,
1817 					struct trace_event_file *file,
1818 					char *glob, char *cmd, char *params);
1819 	int			(*reg)(char *glob,
1820 				       struct event_trigger_ops *ops,
1821 				       struct event_trigger_data *data,
1822 				       struct trace_event_file *file);
1823 	void			(*unreg)(char *glob,
1824 					 struct event_trigger_ops *ops,
1825 					 struct event_trigger_data *data,
1826 					 struct trace_event_file *file);
1827 	void			(*unreg_all)(struct trace_event_file *file);
1828 	int			(*set_filter)(char *filter_str,
1829 					      struct event_trigger_data *data,
1830 					      struct trace_event_file *file);
1831 	struct event_trigger_ops *(*get_trigger_ops)(char *cmd, char *param);
1832 };
1833 
1834 /**
1835  * enum event_command_flags - flags for struct event_command
1836  *
1837  * @POST_TRIGGER: A flag that says whether or not this command needs
1838  *	to have its action delayed until after the current event has
1839  *	been closed.  Some triggers need to avoid being invoked while
1840  *	an event is currently in the process of being logged, since
1841  *	the trigger may itself log data into the trace buffer.  Thus
1842  *	we make sure the current event is committed before invoking
1843  *	those triggers.  To do that, the trigger invocation is split
1844  *	in two - the first part checks the filter using the current
1845  *	trace record; if a command has the @post_trigger flag set, it
1846  *	sets a bit for itself in the return value, otherwise it
1847  *	directly invokes the trigger.  Once all commands have been
1848  *	either invoked or set their return flag, the current record is
1849  *	either committed or discarded.  At that point, if any commands
1850  *	have deferred their triggers, those commands are finally
1851  *	invoked following the close of the current event.  In other
1852  *	words, if the event_trigger_ops @func() probe implementation
1853  *	itself logs to the trace buffer, this flag should be set,
1854  *	otherwise it can be left unspecified.
1855  *
1856  * @NEEDS_REC: A flag that says whether or not this command needs
1857  *	access to the trace record in order to perform its function,
1858  *	regardless of whether or not it has a filter associated with
1859  *	it (filters make a trigger require access to the trace record
1860  *	but are not always present).
1861  */
1862 enum event_command_flags {
1863 	EVENT_CMD_FL_POST_TRIGGER	= 1,
1864 	EVENT_CMD_FL_NEEDS_REC		= 2,
1865 };
1866 
1867 static inline bool event_command_post_trigger(struct event_command *cmd_ops)
1868 {
1869 	return cmd_ops->flags & EVENT_CMD_FL_POST_TRIGGER;
1870 }
1871 
1872 static inline bool event_command_needs_rec(struct event_command *cmd_ops)
1873 {
1874 	return cmd_ops->flags & EVENT_CMD_FL_NEEDS_REC;
1875 }
1876 
1877 extern int trace_event_enable_disable(struct trace_event_file *file,
1878 				      int enable, int soft_disable);
1879 extern int tracing_alloc_snapshot(void);
1880 extern void tracing_snapshot_cond(struct trace_array *tr, void *cond_data);
1881 extern int tracing_snapshot_cond_enable(struct trace_array *tr, void *cond_data, cond_update_fn_t update);
1882 
1883 extern int tracing_snapshot_cond_disable(struct trace_array *tr);
1884 extern void *tracing_cond_snapshot_data(struct trace_array *tr);
1885 
1886 extern const char *__start___trace_bprintk_fmt[];
1887 extern const char *__stop___trace_bprintk_fmt[];
1888 
1889 extern const char *__start___tracepoint_str[];
1890 extern const char *__stop___tracepoint_str[];
1891 
1892 void trace_printk_control(bool enabled);
1893 void trace_printk_init_buffers(void);
1894 void trace_printk_start_comm(void);
1895 int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set);
1896 int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled);
1897 
1898 #define MAX_EVENT_NAME_LEN	64
1899 
1900 extern int trace_run_command(const char *buf, int (*createfn)(int, char**));
1901 extern ssize_t trace_parse_run_command(struct file *file,
1902 		const char __user *buffer, size_t count, loff_t *ppos,
1903 		int (*createfn)(int, char**));
1904 
1905 extern unsigned int err_pos(char *cmd, const char *str);
1906 extern void tracing_log_err(struct trace_array *tr,
1907 			    const char *loc, const char *cmd,
1908 			    const char **errs, u8 type, u8 pos);
1909 
1910 /*
1911  * Normal trace_printk() and friends allocates special buffers
1912  * to do the manipulation, as well as saves the print formats
1913  * into sections to display. But the trace infrastructure wants
1914  * to use these without the added overhead at the price of being
1915  * a bit slower (used mainly for warnings, where we don't care
1916  * about performance). The internal_trace_puts() is for such
1917  * a purpose.
1918  */
1919 #define internal_trace_puts(str) __trace_puts(_THIS_IP_, str, strlen(str))
1920 
1921 #undef FTRACE_ENTRY
1922 #define FTRACE_ENTRY(call, struct_name, id, tstruct, print, filter)	\
1923 	extern struct trace_event_call					\
1924 	__aligned(4) event_##call;
1925 #undef FTRACE_ENTRY_DUP
1926 #define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print, filter)	\
1927 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print), \
1928 		     filter)
1929 #undef FTRACE_ENTRY_PACKED
1930 #define FTRACE_ENTRY_PACKED(call, struct_name, id, tstruct, print, filter) \
1931 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print), \
1932 		     filter)
1933 
1934 #include "trace_entries.h"
1935 
1936 #if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_FUNCTION_TRACER)
1937 int perf_ftrace_event_register(struct trace_event_call *call,
1938 			       enum trace_reg type, void *data);
1939 #else
1940 #define perf_ftrace_event_register NULL
1941 #endif
1942 
1943 #ifdef CONFIG_FTRACE_SYSCALLS
1944 void init_ftrace_syscalls(void);
1945 const char *get_syscall_name(int syscall);
1946 #else
1947 static inline void init_ftrace_syscalls(void) { }
1948 static inline const char *get_syscall_name(int syscall)
1949 {
1950 	return NULL;
1951 }
1952 #endif
1953 
1954 #ifdef CONFIG_EVENT_TRACING
1955 void trace_event_init(void);
1956 void trace_event_eval_update(struct trace_eval_map **map, int len);
1957 #else
1958 static inline void __init trace_event_init(void) { }
1959 static inline void trace_event_eval_update(struct trace_eval_map **map, int len) { }
1960 #endif
1961 
1962 #ifdef CONFIG_TRACER_SNAPSHOT
1963 void tracing_snapshot_instance(struct trace_array *tr);
1964 int tracing_alloc_snapshot_instance(struct trace_array *tr);
1965 #else
1966 static inline void tracing_snapshot_instance(struct trace_array *tr) { }
1967 static inline int tracing_alloc_snapshot_instance(struct trace_array *tr)
1968 {
1969 	return 0;
1970 }
1971 #endif
1972 
1973 #ifdef CONFIG_PREEMPT_TRACER
1974 void tracer_preempt_on(unsigned long a0, unsigned long a1);
1975 void tracer_preempt_off(unsigned long a0, unsigned long a1);
1976 #else
1977 static inline void tracer_preempt_on(unsigned long a0, unsigned long a1) { }
1978 static inline void tracer_preempt_off(unsigned long a0, unsigned long a1) { }
1979 #endif
1980 #ifdef CONFIG_IRQSOFF_TRACER
1981 void tracer_hardirqs_on(unsigned long a0, unsigned long a1);
1982 void tracer_hardirqs_off(unsigned long a0, unsigned long a1);
1983 #else
1984 static inline void tracer_hardirqs_on(unsigned long a0, unsigned long a1) { }
1985 static inline void tracer_hardirqs_off(unsigned long a0, unsigned long a1) { }
1986 #endif
1987 
1988 extern struct trace_iterator *tracepoint_print_iter;
1989 
1990 /*
1991  * Reset the state of the trace_iterator so that it can read consumed data.
1992  * Normally, the trace_iterator is used for reading the data when it is not
1993  * consumed, and must retain state.
1994  */
1995 static __always_inline void trace_iterator_reset(struct trace_iterator *iter)
1996 {
1997 	const size_t offset = offsetof(struct trace_iterator, seq);
1998 
1999 	/*
2000 	 * Keep gcc from complaining about overwriting more than just one
2001 	 * member in the structure.
2002 	 */
2003 	memset((char *)iter + offset, 0, sizeof(struct trace_iterator) - offset);
2004 
2005 	iter->pos = -1;
2006 }
2007 
2008 #endif /* _LINUX_KERNEL_TRACE_H */
2009