xref: /linux/kernel/trace/trace.h (revision 34f71a4a2de84dde52ccfcb96ce25240ea7981a8)
1 // SPDX-License-Identifier: GPL-2.0
2 
3 #ifndef _LINUX_KERNEL_TRACE_H
4 #define _LINUX_KERNEL_TRACE_H
5 
6 #include <linux/fs.h>
7 #include <linux/atomic.h>
8 #include <linux/sched.h>
9 #include <linux/clocksource.h>
10 #include <linux/ring_buffer.h>
11 #include <linux/mmiotrace.h>
12 #include <linux/tracepoint.h>
13 #include <linux/ftrace.h>
14 #include <linux/trace.h>
15 #include <linux/hw_breakpoint.h>
16 #include <linux/trace_seq.h>
17 #include <linux/trace_events.h>
18 #include <linux/compiler.h>
19 #include <linux/glob.h>
20 #include <linux/irq_work.h>
21 #include <linux/workqueue.h>
22 
23 #ifdef CONFIG_FTRACE_SYSCALLS
24 #include <asm/unistd.h>		/* For NR_SYSCALLS	     */
25 #include <asm/syscall.h>	/* some archs define it here */
26 #endif
27 
28 enum trace_type {
29 	__TRACE_FIRST_TYPE = 0,
30 
31 	TRACE_FN,
32 	TRACE_CTX,
33 	TRACE_WAKE,
34 	TRACE_STACK,
35 	TRACE_PRINT,
36 	TRACE_BPRINT,
37 	TRACE_MMIO_RW,
38 	TRACE_MMIO_MAP,
39 	TRACE_BRANCH,
40 	TRACE_GRAPH_RET,
41 	TRACE_GRAPH_ENT,
42 	TRACE_USER_STACK,
43 	TRACE_BLK,
44 	TRACE_BPUTS,
45 	TRACE_HWLAT,
46 	TRACE_RAW_DATA,
47 
48 	__TRACE_LAST_TYPE,
49 };
50 
51 
52 #undef __field
53 #define __field(type, item)		type	item;
54 
55 #undef __field_struct
56 #define __field_struct(type, item)	__field(type, item)
57 
58 #undef __field_desc
59 #define __field_desc(type, container, item)
60 
61 #undef __array
62 #define __array(type, item, size)	type	item[size];
63 
64 #undef __array_desc
65 #define __array_desc(type, container, item, size)
66 
67 #undef __dynamic_array
68 #define __dynamic_array(type, item)	type	item[];
69 
70 #undef F_STRUCT
71 #define F_STRUCT(args...)		args
72 
73 #undef FTRACE_ENTRY
74 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print, filter)	\
75 	struct struct_name {						\
76 		struct trace_entry	ent;				\
77 		tstruct							\
78 	}
79 
80 #undef FTRACE_ENTRY_DUP
81 #define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk, filter)
82 
83 #undef FTRACE_ENTRY_REG
84 #define FTRACE_ENTRY_REG(name, struct_name, id, tstruct, print,	\
85 			 filter, regfn) \
86 	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print), \
87 		     filter)
88 
89 #undef FTRACE_ENTRY_PACKED
90 #define FTRACE_ENTRY_PACKED(name, struct_name, id, tstruct, print,	\
91 			    filter)					\
92 	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print), \
93 		     filter) __packed
94 
95 #include "trace_entries.h"
96 
97 /* Use this for memory failure errors */
98 #define MEM_FAIL(condition, fmt, ...) ({			\
99 	static bool __section(.data.once) __warned;		\
100 	int __ret_warn_once = !!(condition);			\
101 								\
102 	if (unlikely(__ret_warn_once && !__warned)) {		\
103 		__warned = true;				\
104 		pr_err("ERROR: " fmt, ##__VA_ARGS__);		\
105 	}							\
106 	unlikely(__ret_warn_once);				\
107 })
108 
109 /*
110  * syscalls are special, and need special handling, this is why
111  * they are not included in trace_entries.h
112  */
113 struct syscall_trace_enter {
114 	struct trace_entry	ent;
115 	int			nr;
116 	unsigned long		args[];
117 };
118 
119 struct syscall_trace_exit {
120 	struct trace_entry	ent;
121 	int			nr;
122 	long			ret;
123 };
124 
125 struct kprobe_trace_entry_head {
126 	struct trace_entry	ent;
127 	unsigned long		ip;
128 };
129 
130 struct kretprobe_trace_entry_head {
131 	struct trace_entry	ent;
132 	unsigned long		func;
133 	unsigned long		ret_ip;
134 };
135 
136 /*
137  * trace_flag_type is an enumeration that holds different
138  * states when a trace occurs. These are:
139  *  IRQS_OFF		- interrupts were disabled
140  *  IRQS_NOSUPPORT	- arch does not support irqs_disabled_flags
141  *  NEED_RESCHED	- reschedule is requested
142  *  HARDIRQ		- inside an interrupt handler
143  *  SOFTIRQ		- inside a softirq handler
144  */
145 enum trace_flag_type {
146 	TRACE_FLAG_IRQS_OFF		= 0x01,
147 	TRACE_FLAG_IRQS_NOSUPPORT	= 0x02,
148 	TRACE_FLAG_NEED_RESCHED		= 0x04,
149 	TRACE_FLAG_HARDIRQ		= 0x08,
150 	TRACE_FLAG_SOFTIRQ		= 0x10,
151 	TRACE_FLAG_PREEMPT_RESCHED	= 0x20,
152 	TRACE_FLAG_NMI			= 0x40,
153 };
154 
155 #define TRACE_BUF_SIZE		1024
156 
157 struct trace_array;
158 
159 /*
160  * The CPU trace array - it consists of thousands of trace entries
161  * plus some other descriptor data: (for example which task started
162  * the trace, etc.)
163  */
164 struct trace_array_cpu {
165 	atomic_t		disabled;
166 	void			*buffer_page;	/* ring buffer spare */
167 
168 	unsigned long		entries;
169 	unsigned long		saved_latency;
170 	unsigned long		critical_start;
171 	unsigned long		critical_end;
172 	unsigned long		critical_sequence;
173 	unsigned long		nice;
174 	unsigned long		policy;
175 	unsigned long		rt_priority;
176 	unsigned long		skipped_entries;
177 	u64			preempt_timestamp;
178 	pid_t			pid;
179 	kuid_t			uid;
180 	char			comm[TASK_COMM_LEN];
181 
182 	bool			ignore_pid;
183 #ifdef CONFIG_FUNCTION_TRACER
184 	bool			ftrace_ignore_pid;
185 #endif
186 };
187 
188 struct tracer;
189 struct trace_option_dentry;
190 
191 struct array_buffer {
192 	struct trace_array		*tr;
193 	struct trace_buffer		*buffer;
194 	struct trace_array_cpu __percpu	*data;
195 	u64				time_start;
196 	int				cpu;
197 };
198 
199 #define TRACE_FLAGS_MAX_SIZE		32
200 
201 struct trace_options {
202 	struct tracer			*tracer;
203 	struct trace_option_dentry	*topts;
204 };
205 
206 struct trace_pid_list {
207 	int				pid_max;
208 	unsigned long			*pids;
209 };
210 
211 typedef bool (*cond_update_fn_t)(struct trace_array *tr, void *cond_data);
212 
213 /**
214  * struct cond_snapshot - conditional snapshot data and callback
215  *
216  * The cond_snapshot structure encapsulates a callback function and
217  * data associated with the snapshot for a given tracing instance.
218  *
219  * When a snapshot is taken conditionally, by invoking
220  * tracing_snapshot_cond(tr, cond_data), the cond_data passed in is
221  * passed in turn to the cond_snapshot.update() function.  That data
222  * can be compared by the update() implementation with the cond_data
223  * contained wihin the struct cond_snapshot instance associated with
224  * the trace_array.  Because the tr->max_lock is held throughout the
225  * update() call, the update() function can directly retrieve the
226  * cond_snapshot and cond_data associated with the per-instance
227  * snapshot associated with the trace_array.
228  *
229  * The cond_snapshot.update() implementation can save data to be
230  * associated with the snapshot if it decides to, and returns 'true'
231  * in that case, or it returns 'false' if the conditional snapshot
232  * shouldn't be taken.
233  *
234  * The cond_snapshot instance is created and associated with the
235  * user-defined cond_data by tracing_cond_snapshot_enable().
236  * Likewise, the cond_snapshot instance is destroyed and is no longer
237  * associated with the trace instance by
238  * tracing_cond_snapshot_disable().
239  *
240  * The method below is required.
241  *
242  * @update: When a conditional snapshot is invoked, the update()
243  *	callback function is invoked with the tr->max_lock held.  The
244  *	update() implementation signals whether or not to actually
245  *	take the snapshot, by returning 'true' if so, 'false' if no
246  *	snapshot should be taken.  Because the max_lock is held for
247  *	the duration of update(), the implementation is safe to
248  *	directly retrieven and save any implementation data it needs
249  *	to in association with the snapshot.
250  */
251 struct cond_snapshot {
252 	void				*cond_data;
253 	cond_update_fn_t		update;
254 };
255 
256 /*
257  * The trace array - an array of per-CPU trace arrays. This is the
258  * highest level data structure that individual tracers deal with.
259  * They have on/off state as well:
260  */
261 struct trace_array {
262 	struct list_head	list;
263 	char			*name;
264 	struct array_buffer	array_buffer;
265 #ifdef CONFIG_TRACER_MAX_TRACE
266 	/*
267 	 * The max_buffer is used to snapshot the trace when a maximum
268 	 * latency is reached, or when the user initiates a snapshot.
269 	 * Some tracers will use this to store a maximum trace while
270 	 * it continues examining live traces.
271 	 *
272 	 * The buffers for the max_buffer are set up the same as the array_buffer
273 	 * When a snapshot is taken, the buffer of the max_buffer is swapped
274 	 * with the buffer of the array_buffer and the buffers are reset for
275 	 * the array_buffer so the tracing can continue.
276 	 */
277 	struct array_buffer	max_buffer;
278 	bool			allocated_snapshot;
279 #endif
280 #if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)
281 	unsigned long		max_latency;
282 #ifdef CONFIG_FSNOTIFY
283 	struct dentry		*d_max_latency;
284 	struct work_struct	fsnotify_work;
285 	struct irq_work		fsnotify_irqwork;
286 #endif
287 #endif
288 	struct trace_pid_list	__rcu *filtered_pids;
289 	/*
290 	 * max_lock is used to protect the swapping of buffers
291 	 * when taking a max snapshot. The buffers themselves are
292 	 * protected by per_cpu spinlocks. But the action of the swap
293 	 * needs its own lock.
294 	 *
295 	 * This is defined as a arch_spinlock_t in order to help
296 	 * with performance when lockdep debugging is enabled.
297 	 *
298 	 * It is also used in other places outside the update_max_tr
299 	 * so it needs to be defined outside of the
300 	 * CONFIG_TRACER_MAX_TRACE.
301 	 */
302 	arch_spinlock_t		max_lock;
303 	int			buffer_disabled;
304 #ifdef CONFIG_FTRACE_SYSCALLS
305 	int			sys_refcount_enter;
306 	int			sys_refcount_exit;
307 	struct trace_event_file __rcu *enter_syscall_files[NR_syscalls];
308 	struct trace_event_file __rcu *exit_syscall_files[NR_syscalls];
309 #endif
310 	int			stop_count;
311 	int			clock_id;
312 	int			nr_topts;
313 	bool			clear_trace;
314 	int			buffer_percent;
315 	unsigned int		n_err_log_entries;
316 	struct tracer		*current_trace;
317 	unsigned int		trace_flags;
318 	unsigned char		trace_flags_index[TRACE_FLAGS_MAX_SIZE];
319 	unsigned int		flags;
320 	raw_spinlock_t		start_lock;
321 	struct list_head	err_log;
322 	struct dentry		*dir;
323 	struct dentry		*options;
324 	struct dentry		*percpu_dir;
325 	struct dentry		*event_dir;
326 	struct trace_options	*topts;
327 	struct list_head	systems;
328 	struct list_head	events;
329 	struct trace_event_file *trace_marker_file;
330 	cpumask_var_t		tracing_cpumask; /* only trace on set CPUs */
331 	int			ref;
332 #ifdef CONFIG_FUNCTION_TRACER
333 	struct ftrace_ops	*ops;
334 	struct trace_pid_list	__rcu *function_pids;
335 #ifdef CONFIG_DYNAMIC_FTRACE
336 	/* All of these are protected by the ftrace_lock */
337 	struct list_head	func_probes;
338 	struct list_head	mod_trace;
339 	struct list_head	mod_notrace;
340 #endif
341 	/* function tracing enabled */
342 	int			function_enabled;
343 #endif
344 	int			time_stamp_abs_ref;
345 	struct list_head	hist_vars;
346 #ifdef CONFIG_TRACER_SNAPSHOT
347 	struct cond_snapshot	*cond_snapshot;
348 #endif
349 };
350 
351 enum {
352 	TRACE_ARRAY_FL_GLOBAL	= (1 << 0)
353 };
354 
355 extern struct list_head ftrace_trace_arrays;
356 
357 extern struct mutex trace_types_lock;
358 
359 extern int trace_array_get(struct trace_array *tr);
360 extern int tracing_check_open_get_tr(struct trace_array *tr);
361 
362 extern int tracing_set_time_stamp_abs(struct trace_array *tr, bool abs);
363 extern int tracing_set_clock(struct trace_array *tr, const char *clockstr);
364 
365 extern bool trace_clock_in_ns(struct trace_array *tr);
366 
367 /*
368  * The global tracer (top) should be the first trace array added,
369  * but we check the flag anyway.
370  */
371 static inline struct trace_array *top_trace_array(void)
372 {
373 	struct trace_array *tr;
374 
375 	if (list_empty(&ftrace_trace_arrays))
376 		return NULL;
377 
378 	tr = list_entry(ftrace_trace_arrays.prev,
379 			typeof(*tr), list);
380 	WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
381 	return tr;
382 }
383 
384 #define FTRACE_CMP_TYPE(var, type) \
385 	__builtin_types_compatible_p(typeof(var), type *)
386 
387 #undef IF_ASSIGN
388 #define IF_ASSIGN(var, entry, etype, id)			\
389 	if (FTRACE_CMP_TYPE(var, etype)) {			\
390 		var = (typeof(var))(entry);			\
391 		WARN_ON(id != 0 && (entry)->type != id);	\
392 		break;						\
393 	}
394 
395 /* Will cause compile errors if type is not found. */
396 extern void __ftrace_bad_type(void);
397 
398 /*
399  * The trace_assign_type is a verifier that the entry type is
400  * the same as the type being assigned. To add new types simply
401  * add a line with the following format:
402  *
403  * IF_ASSIGN(var, ent, type, id);
404  *
405  *  Where "type" is the trace type that includes the trace_entry
406  *  as the "ent" item. And "id" is the trace identifier that is
407  *  used in the trace_type enum.
408  *
409  *  If the type can have more than one id, then use zero.
410  */
411 #define trace_assign_type(var, ent)					\
412 	do {								\
413 		IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);	\
414 		IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);	\
415 		IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);	\
416 		IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
417 		IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);	\
418 		IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT);	\
419 		IF_ASSIGN(var, ent, struct bputs_entry, TRACE_BPUTS);	\
420 		IF_ASSIGN(var, ent, struct hwlat_entry, TRACE_HWLAT);	\
421 		IF_ASSIGN(var, ent, struct raw_data_entry, TRACE_RAW_DATA);\
422 		IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,		\
423 			  TRACE_MMIO_RW);				\
424 		IF_ASSIGN(var, ent, struct trace_mmiotrace_map,		\
425 			  TRACE_MMIO_MAP);				\
426 		IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
427 		IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,	\
428 			  TRACE_GRAPH_ENT);		\
429 		IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,	\
430 			  TRACE_GRAPH_RET);		\
431 		__ftrace_bad_type();					\
432 	} while (0)
433 
434 /*
435  * An option specific to a tracer. This is a boolean value.
436  * The bit is the bit index that sets its value on the
437  * flags value in struct tracer_flags.
438  */
439 struct tracer_opt {
440 	const char	*name; /* Will appear on the trace_options file */
441 	u32		bit; /* Mask assigned in val field in tracer_flags */
442 };
443 
444 /*
445  * The set of specific options for a tracer. Your tracer
446  * have to set the initial value of the flags val.
447  */
448 struct tracer_flags {
449 	u32			val;
450 	struct tracer_opt	*opts;
451 	struct tracer		*trace;
452 };
453 
454 /* Makes more easy to define a tracer opt */
455 #define TRACER_OPT(s, b)	.name = #s, .bit = b
456 
457 
458 struct trace_option_dentry {
459 	struct tracer_opt		*opt;
460 	struct tracer_flags		*flags;
461 	struct trace_array		*tr;
462 	struct dentry			*entry;
463 };
464 
465 /**
466  * struct tracer - a specific tracer and its callbacks to interact with tracefs
467  * @name: the name chosen to select it on the available_tracers file
468  * @init: called when one switches to this tracer (echo name > current_tracer)
469  * @reset: called when one switches to another tracer
470  * @start: called when tracing is unpaused (echo 1 > tracing_on)
471  * @stop: called when tracing is paused (echo 0 > tracing_on)
472  * @update_thresh: called when tracing_thresh is updated
473  * @open: called when the trace file is opened
474  * @pipe_open: called when the trace_pipe file is opened
475  * @close: called when the trace file is released
476  * @pipe_close: called when the trace_pipe file is released
477  * @read: override the default read callback on trace_pipe
478  * @splice_read: override the default splice_read callback on trace_pipe
479  * @selftest: selftest to run on boot (see trace_selftest.c)
480  * @print_headers: override the first lines that describe your columns
481  * @print_line: callback that prints a trace
482  * @set_flag: signals one of your private flags changed (trace_options file)
483  * @flags: your private flags
484  */
485 struct tracer {
486 	const char		*name;
487 	int			(*init)(struct trace_array *tr);
488 	void			(*reset)(struct trace_array *tr);
489 	void			(*start)(struct trace_array *tr);
490 	void			(*stop)(struct trace_array *tr);
491 	int			(*update_thresh)(struct trace_array *tr);
492 	void			(*open)(struct trace_iterator *iter);
493 	void			(*pipe_open)(struct trace_iterator *iter);
494 	void			(*close)(struct trace_iterator *iter);
495 	void			(*pipe_close)(struct trace_iterator *iter);
496 	ssize_t			(*read)(struct trace_iterator *iter,
497 					struct file *filp, char __user *ubuf,
498 					size_t cnt, loff_t *ppos);
499 	ssize_t			(*splice_read)(struct trace_iterator *iter,
500 					       struct file *filp,
501 					       loff_t *ppos,
502 					       struct pipe_inode_info *pipe,
503 					       size_t len,
504 					       unsigned int flags);
505 #ifdef CONFIG_FTRACE_STARTUP_TEST
506 	int			(*selftest)(struct tracer *trace,
507 					    struct trace_array *tr);
508 #endif
509 	void			(*print_header)(struct seq_file *m);
510 	enum print_line_t	(*print_line)(struct trace_iterator *iter);
511 	/* If you handled the flag setting, return 0 */
512 	int			(*set_flag)(struct trace_array *tr,
513 					    u32 old_flags, u32 bit, int set);
514 	/* Return 0 if OK with change, else return non-zero */
515 	int			(*flag_changed)(struct trace_array *tr,
516 						u32 mask, int set);
517 	struct tracer		*next;
518 	struct tracer_flags	*flags;
519 	int			enabled;
520 	int			ref;
521 	bool			print_max;
522 	bool			allow_instances;
523 #ifdef CONFIG_TRACER_MAX_TRACE
524 	bool			use_max_tr;
525 #endif
526 	/* True if tracer cannot be enabled in kernel param */
527 	bool			noboot;
528 };
529 
530 
531 /* Only current can touch trace_recursion */
532 
533 /*
534  * For function tracing recursion:
535  *  The order of these bits are important.
536  *
537  *  When function tracing occurs, the following steps are made:
538  *   If arch does not support a ftrace feature:
539  *    call internal function (uses INTERNAL bits) which calls...
540  *   If callback is registered to the "global" list, the list
541  *    function is called and recursion checks the GLOBAL bits.
542  *    then this function calls...
543  *   The function callback, which can use the FTRACE bits to
544  *    check for recursion.
545  *
546  * Now if the arch does not suppport a feature, and it calls
547  * the global list function which calls the ftrace callback
548  * all three of these steps will do a recursion protection.
549  * There's no reason to do one if the previous caller already
550  * did. The recursion that we are protecting against will
551  * go through the same steps again.
552  *
553  * To prevent the multiple recursion checks, if a recursion
554  * bit is set that is higher than the MAX bit of the current
555  * check, then we know that the check was made by the previous
556  * caller, and we can skip the current check.
557  */
558 enum {
559 	TRACE_BUFFER_BIT,
560 	TRACE_BUFFER_NMI_BIT,
561 	TRACE_BUFFER_IRQ_BIT,
562 	TRACE_BUFFER_SIRQ_BIT,
563 
564 	/* Start of function recursion bits */
565 	TRACE_FTRACE_BIT,
566 	TRACE_FTRACE_NMI_BIT,
567 	TRACE_FTRACE_IRQ_BIT,
568 	TRACE_FTRACE_SIRQ_BIT,
569 
570 	/* INTERNAL_BITs must be greater than FTRACE_BITs */
571 	TRACE_INTERNAL_BIT,
572 	TRACE_INTERNAL_NMI_BIT,
573 	TRACE_INTERNAL_IRQ_BIT,
574 	TRACE_INTERNAL_SIRQ_BIT,
575 
576 	TRACE_BRANCH_BIT,
577 /*
578  * Abuse of the trace_recursion.
579  * As we need a way to maintain state if we are tracing the function
580  * graph in irq because we want to trace a particular function that
581  * was called in irq context but we have irq tracing off. Since this
582  * can only be modified by current, we can reuse trace_recursion.
583  */
584 	TRACE_IRQ_BIT,
585 
586 	/* Set if the function is in the set_graph_function file */
587 	TRACE_GRAPH_BIT,
588 
589 	/*
590 	 * In the very unlikely case that an interrupt came in
591 	 * at a start of graph tracing, and we want to trace
592 	 * the function in that interrupt, the depth can be greater
593 	 * than zero, because of the preempted start of a previous
594 	 * trace. In an even more unlikely case, depth could be 2
595 	 * if a softirq interrupted the start of graph tracing,
596 	 * followed by an interrupt preempting a start of graph
597 	 * tracing in the softirq, and depth can even be 3
598 	 * if an NMI came in at the start of an interrupt function
599 	 * that preempted a softirq start of a function that
600 	 * preempted normal context!!!! Luckily, it can't be
601 	 * greater than 3, so the next two bits are a mask
602 	 * of what the depth is when we set TRACE_GRAPH_BIT
603 	 */
604 
605 	TRACE_GRAPH_DEPTH_START_BIT,
606 	TRACE_GRAPH_DEPTH_END_BIT,
607 
608 	/*
609 	 * To implement set_graph_notrace, if this bit is set, we ignore
610 	 * function graph tracing of called functions, until the return
611 	 * function is called to clear it.
612 	 */
613 	TRACE_GRAPH_NOTRACE_BIT,
614 };
615 
616 #define trace_recursion_set(bit)	do { (current)->trace_recursion |= (1<<(bit)); } while (0)
617 #define trace_recursion_clear(bit)	do { (current)->trace_recursion &= ~(1<<(bit)); } while (0)
618 #define trace_recursion_test(bit)	((current)->trace_recursion & (1<<(bit)))
619 
620 #define trace_recursion_depth() \
621 	(((current)->trace_recursion >> TRACE_GRAPH_DEPTH_START_BIT) & 3)
622 #define trace_recursion_set_depth(depth) \
623 	do {								\
624 		current->trace_recursion &=				\
625 			~(3 << TRACE_GRAPH_DEPTH_START_BIT);		\
626 		current->trace_recursion |=				\
627 			((depth) & 3) << TRACE_GRAPH_DEPTH_START_BIT;	\
628 	} while (0)
629 
630 #define TRACE_CONTEXT_BITS	4
631 
632 #define TRACE_FTRACE_START	TRACE_FTRACE_BIT
633 #define TRACE_FTRACE_MAX	((1 << (TRACE_FTRACE_START + TRACE_CONTEXT_BITS)) - 1)
634 
635 #define TRACE_LIST_START	TRACE_INTERNAL_BIT
636 #define TRACE_LIST_MAX		((1 << (TRACE_LIST_START + TRACE_CONTEXT_BITS)) - 1)
637 
638 #define TRACE_CONTEXT_MASK	TRACE_LIST_MAX
639 
640 static __always_inline int trace_get_context_bit(void)
641 {
642 	int bit;
643 
644 	if (in_interrupt()) {
645 		if (in_nmi())
646 			bit = 0;
647 
648 		else if (in_irq())
649 			bit = 1;
650 		else
651 			bit = 2;
652 	} else
653 		bit = 3;
654 
655 	return bit;
656 }
657 
658 static __always_inline int trace_test_and_set_recursion(int start, int max)
659 {
660 	unsigned int val = current->trace_recursion;
661 	int bit;
662 
663 	/* A previous recursion check was made */
664 	if ((val & TRACE_CONTEXT_MASK) > max)
665 		return 0;
666 
667 	bit = trace_get_context_bit() + start;
668 	if (unlikely(val & (1 << bit)))
669 		return -1;
670 
671 	val |= 1 << bit;
672 	current->trace_recursion = val;
673 	barrier();
674 
675 	return bit;
676 }
677 
678 static __always_inline void trace_clear_recursion(int bit)
679 {
680 	unsigned int val = current->trace_recursion;
681 
682 	if (!bit)
683 		return;
684 
685 	bit = 1 << bit;
686 	val &= ~bit;
687 
688 	barrier();
689 	current->trace_recursion = val;
690 }
691 
692 static inline struct ring_buffer_iter *
693 trace_buffer_iter(struct trace_iterator *iter, int cpu)
694 {
695 	return iter->buffer_iter ? iter->buffer_iter[cpu] : NULL;
696 }
697 
698 int tracer_init(struct tracer *t, struct trace_array *tr);
699 int tracing_is_enabled(void);
700 void tracing_reset_online_cpus(struct array_buffer *buf);
701 void tracing_reset_current(int cpu);
702 void tracing_reset_all_online_cpus(void);
703 int tracing_open_generic(struct inode *inode, struct file *filp);
704 int tracing_open_generic_tr(struct inode *inode, struct file *filp);
705 bool tracing_is_disabled(void);
706 bool tracer_tracing_is_on(struct trace_array *tr);
707 void tracer_tracing_on(struct trace_array *tr);
708 void tracer_tracing_off(struct trace_array *tr);
709 struct dentry *trace_create_file(const char *name,
710 				 umode_t mode,
711 				 struct dentry *parent,
712 				 void *data,
713 				 const struct file_operations *fops);
714 
715 struct dentry *tracing_init_dentry(void);
716 
717 struct ring_buffer_event;
718 
719 struct ring_buffer_event *
720 trace_buffer_lock_reserve(struct trace_buffer *buffer,
721 			  int type,
722 			  unsigned long len,
723 			  unsigned long flags,
724 			  int pc);
725 
726 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
727 						struct trace_array_cpu *data);
728 
729 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
730 					  int *ent_cpu, u64 *ent_ts);
731 
732 void trace_buffer_unlock_commit_nostack(struct trace_buffer *buffer,
733 					struct ring_buffer_event *event);
734 
735 int trace_empty(struct trace_iterator *iter);
736 
737 void *trace_find_next_entry_inc(struct trace_iterator *iter);
738 
739 void trace_init_global_iter(struct trace_iterator *iter);
740 
741 void tracing_iter_reset(struct trace_iterator *iter, int cpu);
742 
743 unsigned long trace_total_entries_cpu(struct trace_array *tr, int cpu);
744 unsigned long trace_total_entries(struct trace_array *tr);
745 
746 void trace_function(struct trace_array *tr,
747 		    unsigned long ip,
748 		    unsigned long parent_ip,
749 		    unsigned long flags, int pc);
750 void trace_graph_function(struct trace_array *tr,
751 		    unsigned long ip,
752 		    unsigned long parent_ip,
753 		    unsigned long flags, int pc);
754 void trace_latency_header(struct seq_file *m);
755 void trace_default_header(struct seq_file *m);
756 void print_trace_header(struct seq_file *m, struct trace_iterator *iter);
757 int trace_empty(struct trace_iterator *iter);
758 
759 void trace_graph_return(struct ftrace_graph_ret *trace);
760 int trace_graph_entry(struct ftrace_graph_ent *trace);
761 void set_graph_array(struct trace_array *tr);
762 
763 void tracing_start_cmdline_record(void);
764 void tracing_stop_cmdline_record(void);
765 void tracing_start_tgid_record(void);
766 void tracing_stop_tgid_record(void);
767 
768 int register_tracer(struct tracer *type);
769 int is_tracing_stopped(void);
770 
771 loff_t tracing_lseek(struct file *file, loff_t offset, int whence);
772 
773 extern cpumask_var_t __read_mostly tracing_buffer_mask;
774 
775 #define for_each_tracing_cpu(cpu)	\
776 	for_each_cpu(cpu, tracing_buffer_mask)
777 
778 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
779 
780 extern unsigned long tracing_thresh;
781 
782 /* PID filtering */
783 
784 extern int pid_max;
785 
786 bool trace_find_filtered_pid(struct trace_pid_list *filtered_pids,
787 			     pid_t search_pid);
788 bool trace_ignore_this_task(struct trace_pid_list *filtered_pids,
789 			    struct task_struct *task);
790 void trace_filter_add_remove_task(struct trace_pid_list *pid_list,
791 				  struct task_struct *self,
792 				  struct task_struct *task);
793 void *trace_pid_next(struct trace_pid_list *pid_list, void *v, loff_t *pos);
794 void *trace_pid_start(struct trace_pid_list *pid_list, loff_t *pos);
795 int trace_pid_show(struct seq_file *m, void *v);
796 void trace_free_pid_list(struct trace_pid_list *pid_list);
797 int trace_pid_write(struct trace_pid_list *filtered_pids,
798 		    struct trace_pid_list **new_pid_list,
799 		    const char __user *ubuf, size_t cnt);
800 
801 #ifdef CONFIG_TRACER_MAX_TRACE
802 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu,
803 		   void *cond_data);
804 void update_max_tr_single(struct trace_array *tr,
805 			  struct task_struct *tsk, int cpu);
806 #endif /* CONFIG_TRACER_MAX_TRACE */
807 
808 #if (defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)) && \
809 	defined(CONFIG_FSNOTIFY)
810 
811 void latency_fsnotify(struct trace_array *tr);
812 
813 #else
814 
815 static inline void latency_fsnotify(struct trace_array *tr) { }
816 
817 #endif
818 
819 #ifdef CONFIG_STACKTRACE
820 void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
821 		   int pc);
822 #else
823 static inline void __trace_stack(struct trace_array *tr, unsigned long flags,
824 				 int skip, int pc)
825 {
826 }
827 #endif /* CONFIG_STACKTRACE */
828 
829 extern u64 ftrace_now(int cpu);
830 
831 extern void trace_find_cmdline(int pid, char comm[]);
832 extern int trace_find_tgid(int pid);
833 extern void trace_event_follow_fork(struct trace_array *tr, bool enable);
834 
835 #ifdef CONFIG_DYNAMIC_FTRACE
836 extern unsigned long ftrace_update_tot_cnt;
837 extern unsigned long ftrace_number_of_pages;
838 extern unsigned long ftrace_number_of_groups;
839 void ftrace_init_trace_array(struct trace_array *tr);
840 #else
841 static inline void ftrace_init_trace_array(struct trace_array *tr) { }
842 #endif
843 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
844 extern int DYN_FTRACE_TEST_NAME(void);
845 #define DYN_FTRACE_TEST_NAME2 trace_selftest_dynamic_test_func2
846 extern int DYN_FTRACE_TEST_NAME2(void);
847 
848 extern bool ring_buffer_expanded;
849 extern bool tracing_selftest_disabled;
850 
851 #ifdef CONFIG_FTRACE_STARTUP_TEST
852 extern int trace_selftest_startup_function(struct tracer *trace,
853 					   struct trace_array *tr);
854 extern int trace_selftest_startup_function_graph(struct tracer *trace,
855 						 struct trace_array *tr);
856 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
857 					  struct trace_array *tr);
858 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
859 					     struct trace_array *tr);
860 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
861 						 struct trace_array *tr);
862 extern int trace_selftest_startup_wakeup(struct tracer *trace,
863 					 struct trace_array *tr);
864 extern int trace_selftest_startup_nop(struct tracer *trace,
865 					 struct trace_array *tr);
866 extern int trace_selftest_startup_branch(struct tracer *trace,
867 					 struct trace_array *tr);
868 /*
869  * Tracer data references selftest functions that only occur
870  * on boot up. These can be __init functions. Thus, when selftests
871  * are enabled, then the tracers need to reference __init functions.
872  */
873 #define __tracer_data		__refdata
874 #else
875 /* Tracers are seldom changed. Optimize when selftests are disabled. */
876 #define __tracer_data		__read_mostly
877 #endif /* CONFIG_FTRACE_STARTUP_TEST */
878 
879 extern void *head_page(struct trace_array_cpu *data);
880 extern unsigned long long ns2usecs(u64 nsec);
881 extern int
882 trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
883 extern int
884 trace_vprintk(unsigned long ip, const char *fmt, va_list args);
885 extern int
886 trace_array_vprintk(struct trace_array *tr,
887 		    unsigned long ip, const char *fmt, va_list args);
888 int trace_array_printk_buf(struct trace_buffer *buffer,
889 			   unsigned long ip, const char *fmt, ...);
890 void trace_printk_seq(struct trace_seq *s);
891 enum print_line_t print_trace_line(struct trace_iterator *iter);
892 
893 extern char trace_find_mark(unsigned long long duration);
894 
895 struct ftrace_hash;
896 
897 struct ftrace_mod_load {
898 	struct list_head	list;
899 	char			*func;
900 	char			*module;
901 	int			 enable;
902 };
903 
904 enum {
905 	FTRACE_HASH_FL_MOD	= (1 << 0),
906 };
907 
908 struct ftrace_hash {
909 	unsigned long		size_bits;
910 	struct hlist_head	*buckets;
911 	unsigned long		count;
912 	unsigned long		flags;
913 	struct rcu_head		rcu;
914 };
915 
916 struct ftrace_func_entry *
917 ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip);
918 
919 static __always_inline bool ftrace_hash_empty(struct ftrace_hash *hash)
920 {
921 	return !hash || !(hash->count || (hash->flags & FTRACE_HASH_FL_MOD));
922 }
923 
924 /* Standard output formatting function used for function return traces */
925 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
926 
927 /* Flag options */
928 #define TRACE_GRAPH_PRINT_OVERRUN       0x1
929 #define TRACE_GRAPH_PRINT_CPU           0x2
930 #define TRACE_GRAPH_PRINT_OVERHEAD      0x4
931 #define TRACE_GRAPH_PRINT_PROC          0x8
932 #define TRACE_GRAPH_PRINT_DURATION      0x10
933 #define TRACE_GRAPH_PRINT_ABS_TIME      0x20
934 #define TRACE_GRAPH_PRINT_REL_TIME      0x40
935 #define TRACE_GRAPH_PRINT_IRQS          0x80
936 #define TRACE_GRAPH_PRINT_TAIL          0x100
937 #define TRACE_GRAPH_SLEEP_TIME          0x200
938 #define TRACE_GRAPH_GRAPH_TIME          0x400
939 #define TRACE_GRAPH_PRINT_FILL_SHIFT	28
940 #define TRACE_GRAPH_PRINT_FILL_MASK	(0x3 << TRACE_GRAPH_PRINT_FILL_SHIFT)
941 
942 extern void ftrace_graph_sleep_time_control(bool enable);
943 
944 #ifdef CONFIG_FUNCTION_PROFILER
945 extern void ftrace_graph_graph_time_control(bool enable);
946 #else
947 static inline void ftrace_graph_graph_time_control(bool enable) { }
948 #endif
949 
950 extern enum print_line_t
951 print_graph_function_flags(struct trace_iterator *iter, u32 flags);
952 extern void print_graph_headers_flags(struct seq_file *s, u32 flags);
953 extern void
954 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
955 extern void graph_trace_open(struct trace_iterator *iter);
956 extern void graph_trace_close(struct trace_iterator *iter);
957 extern int __trace_graph_entry(struct trace_array *tr,
958 			       struct ftrace_graph_ent *trace,
959 			       unsigned long flags, int pc);
960 extern void __trace_graph_return(struct trace_array *tr,
961 				 struct ftrace_graph_ret *trace,
962 				 unsigned long flags, int pc);
963 
964 #ifdef CONFIG_DYNAMIC_FTRACE
965 extern struct ftrace_hash *ftrace_graph_hash;
966 extern struct ftrace_hash *ftrace_graph_notrace_hash;
967 
968 static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace)
969 {
970 	unsigned long addr = trace->func;
971 	int ret = 0;
972 
973 	preempt_disable_notrace();
974 
975 	if (ftrace_hash_empty(ftrace_graph_hash)) {
976 		ret = 1;
977 		goto out;
978 	}
979 
980 	if (ftrace_lookup_ip(ftrace_graph_hash, addr)) {
981 
982 		/*
983 		 * This needs to be cleared on the return functions
984 		 * when the depth is zero.
985 		 */
986 		trace_recursion_set(TRACE_GRAPH_BIT);
987 		trace_recursion_set_depth(trace->depth);
988 
989 		/*
990 		 * If no irqs are to be traced, but a set_graph_function
991 		 * is set, and called by an interrupt handler, we still
992 		 * want to trace it.
993 		 */
994 		if (in_irq())
995 			trace_recursion_set(TRACE_IRQ_BIT);
996 		else
997 			trace_recursion_clear(TRACE_IRQ_BIT);
998 		ret = 1;
999 	}
1000 
1001 out:
1002 	preempt_enable_notrace();
1003 	return ret;
1004 }
1005 
1006 static inline void ftrace_graph_addr_finish(struct ftrace_graph_ret *trace)
1007 {
1008 	if (trace_recursion_test(TRACE_GRAPH_BIT) &&
1009 	    trace->depth == trace_recursion_depth())
1010 		trace_recursion_clear(TRACE_GRAPH_BIT);
1011 }
1012 
1013 static inline int ftrace_graph_notrace_addr(unsigned long addr)
1014 {
1015 	int ret = 0;
1016 
1017 	preempt_disable_notrace();
1018 
1019 	if (ftrace_lookup_ip(ftrace_graph_notrace_hash, addr))
1020 		ret = 1;
1021 
1022 	preempt_enable_notrace();
1023 	return ret;
1024 }
1025 #else
1026 static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace)
1027 {
1028 	return 1;
1029 }
1030 
1031 static inline int ftrace_graph_notrace_addr(unsigned long addr)
1032 {
1033 	return 0;
1034 }
1035 static inline void ftrace_graph_addr_finish(struct ftrace_graph_ret *trace)
1036 { }
1037 #endif /* CONFIG_DYNAMIC_FTRACE */
1038 
1039 extern unsigned int fgraph_max_depth;
1040 
1041 static inline bool ftrace_graph_ignore_func(struct ftrace_graph_ent *trace)
1042 {
1043 	/* trace it when it is-nested-in or is a function enabled. */
1044 	return !(trace_recursion_test(TRACE_GRAPH_BIT) ||
1045 		 ftrace_graph_addr(trace)) ||
1046 		(trace->depth < 0) ||
1047 		(fgraph_max_depth && trace->depth >= fgraph_max_depth);
1048 }
1049 
1050 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
1051 static inline enum print_line_t
1052 print_graph_function_flags(struct trace_iterator *iter, u32 flags)
1053 {
1054 	return TRACE_TYPE_UNHANDLED;
1055 }
1056 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
1057 
1058 extern struct list_head ftrace_pids;
1059 
1060 #ifdef CONFIG_FUNCTION_TRACER
1061 struct ftrace_func_command {
1062 	struct list_head	list;
1063 	char			*name;
1064 	int			(*func)(struct trace_array *tr,
1065 					struct ftrace_hash *hash,
1066 					char *func, char *cmd,
1067 					char *params, int enable);
1068 };
1069 extern bool ftrace_filter_param __initdata;
1070 static inline int ftrace_trace_task(struct trace_array *tr)
1071 {
1072 	return !this_cpu_read(tr->array_buffer.data->ftrace_ignore_pid);
1073 }
1074 extern int ftrace_is_dead(void);
1075 int ftrace_create_function_files(struct trace_array *tr,
1076 				 struct dentry *parent);
1077 void ftrace_destroy_function_files(struct trace_array *tr);
1078 void ftrace_init_global_array_ops(struct trace_array *tr);
1079 void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func);
1080 void ftrace_reset_array_ops(struct trace_array *tr);
1081 void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer);
1082 void ftrace_init_tracefs_toplevel(struct trace_array *tr,
1083 				  struct dentry *d_tracer);
1084 void ftrace_clear_pids(struct trace_array *tr);
1085 int init_function_trace(void);
1086 void ftrace_pid_follow_fork(struct trace_array *tr, bool enable);
1087 #else
1088 static inline int ftrace_trace_task(struct trace_array *tr)
1089 {
1090 	return 1;
1091 }
1092 static inline int ftrace_is_dead(void) { return 0; }
1093 static inline int
1094 ftrace_create_function_files(struct trace_array *tr,
1095 			     struct dentry *parent)
1096 {
1097 	return 0;
1098 }
1099 static inline void ftrace_destroy_function_files(struct trace_array *tr) { }
1100 static inline __init void
1101 ftrace_init_global_array_ops(struct trace_array *tr) { }
1102 static inline void ftrace_reset_array_ops(struct trace_array *tr) { }
1103 static inline void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d) { }
1104 static inline void ftrace_init_tracefs_toplevel(struct trace_array *tr, struct dentry *d) { }
1105 static inline void ftrace_clear_pids(struct trace_array *tr) { }
1106 static inline int init_function_trace(void) { return 0; }
1107 static inline void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) { }
1108 /* ftace_func_t type is not defined, use macro instead of static inline */
1109 #define ftrace_init_array_ops(tr, func) do { } while (0)
1110 #endif /* CONFIG_FUNCTION_TRACER */
1111 
1112 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
1113 
1114 struct ftrace_probe_ops {
1115 	void			(*func)(unsigned long ip,
1116 					unsigned long parent_ip,
1117 					struct trace_array *tr,
1118 					struct ftrace_probe_ops *ops,
1119 					void *data);
1120 	int			(*init)(struct ftrace_probe_ops *ops,
1121 					struct trace_array *tr,
1122 					unsigned long ip, void *init_data,
1123 					void **data);
1124 	void			(*free)(struct ftrace_probe_ops *ops,
1125 					struct trace_array *tr,
1126 					unsigned long ip, void *data);
1127 	int			(*print)(struct seq_file *m,
1128 					 unsigned long ip,
1129 					 struct ftrace_probe_ops *ops,
1130 					 void *data);
1131 };
1132 
1133 struct ftrace_func_mapper;
1134 typedef int (*ftrace_mapper_func)(void *data);
1135 
1136 struct ftrace_func_mapper *allocate_ftrace_func_mapper(void);
1137 void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
1138 					   unsigned long ip);
1139 int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
1140 			       unsigned long ip, void *data);
1141 void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
1142 				   unsigned long ip);
1143 void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
1144 			     ftrace_mapper_func free_func);
1145 
1146 extern int
1147 register_ftrace_function_probe(char *glob, struct trace_array *tr,
1148 			       struct ftrace_probe_ops *ops, void *data);
1149 extern int
1150 unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
1151 				      struct ftrace_probe_ops *ops);
1152 extern void clear_ftrace_function_probes(struct trace_array *tr);
1153 
1154 int register_ftrace_command(struct ftrace_func_command *cmd);
1155 int unregister_ftrace_command(struct ftrace_func_command *cmd);
1156 
1157 void ftrace_create_filter_files(struct ftrace_ops *ops,
1158 				struct dentry *parent);
1159 void ftrace_destroy_filter_files(struct ftrace_ops *ops);
1160 #else
1161 struct ftrace_func_command;
1162 
1163 static inline __init int register_ftrace_command(struct ftrace_func_command *cmd)
1164 {
1165 	return -EINVAL;
1166 }
1167 static inline __init int unregister_ftrace_command(char *cmd_name)
1168 {
1169 	return -EINVAL;
1170 }
1171 static inline void clear_ftrace_function_probes(struct trace_array *tr)
1172 {
1173 }
1174 
1175 /*
1176  * The ops parameter passed in is usually undefined.
1177  * This must be a macro.
1178  */
1179 #define ftrace_create_filter_files(ops, parent) do { } while (0)
1180 #define ftrace_destroy_filter_files(ops) do { } while (0)
1181 #endif /* CONFIG_FUNCTION_TRACER && CONFIG_DYNAMIC_FTRACE */
1182 
1183 bool ftrace_event_is_function(struct trace_event_call *call);
1184 
1185 /*
1186  * struct trace_parser - servers for reading the user input separated by spaces
1187  * @cont: set if the input is not complete - no final space char was found
1188  * @buffer: holds the parsed user input
1189  * @idx: user input length
1190  * @size: buffer size
1191  */
1192 struct trace_parser {
1193 	bool		cont;
1194 	char		*buffer;
1195 	unsigned	idx;
1196 	unsigned	size;
1197 };
1198 
1199 static inline bool trace_parser_loaded(struct trace_parser *parser)
1200 {
1201 	return (parser->idx != 0);
1202 }
1203 
1204 static inline bool trace_parser_cont(struct trace_parser *parser)
1205 {
1206 	return parser->cont;
1207 }
1208 
1209 static inline void trace_parser_clear(struct trace_parser *parser)
1210 {
1211 	parser->cont = false;
1212 	parser->idx = 0;
1213 }
1214 
1215 extern int trace_parser_get_init(struct trace_parser *parser, int size);
1216 extern void trace_parser_put(struct trace_parser *parser);
1217 extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
1218 	size_t cnt, loff_t *ppos);
1219 
1220 /*
1221  * Only create function graph options if function graph is configured.
1222  */
1223 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1224 # define FGRAPH_FLAGS						\
1225 		C(DISPLAY_GRAPH,	"display-graph"),
1226 #else
1227 # define FGRAPH_FLAGS
1228 #endif
1229 
1230 #ifdef CONFIG_BRANCH_TRACER
1231 # define BRANCH_FLAGS					\
1232 		C(BRANCH,		"branch"),
1233 #else
1234 # define BRANCH_FLAGS
1235 #endif
1236 
1237 #ifdef CONFIG_FUNCTION_TRACER
1238 # define FUNCTION_FLAGS						\
1239 		C(FUNCTION,		"function-trace"),	\
1240 		C(FUNC_FORK,		"function-fork"),
1241 # define FUNCTION_DEFAULT_FLAGS		TRACE_ITER_FUNCTION
1242 #else
1243 # define FUNCTION_FLAGS
1244 # define FUNCTION_DEFAULT_FLAGS		0UL
1245 # define TRACE_ITER_FUNC_FORK		0UL
1246 #endif
1247 
1248 #ifdef CONFIG_STACKTRACE
1249 # define STACK_FLAGS				\
1250 		C(STACKTRACE,		"stacktrace"),
1251 #else
1252 # define STACK_FLAGS
1253 #endif
1254 
1255 /*
1256  * trace_iterator_flags is an enumeration that defines bit
1257  * positions into trace_flags that controls the output.
1258  *
1259  * NOTE: These bits must match the trace_options array in
1260  *       trace.c (this macro guarantees it).
1261  */
1262 #define TRACE_FLAGS						\
1263 		C(PRINT_PARENT,		"print-parent"),	\
1264 		C(SYM_OFFSET,		"sym-offset"),		\
1265 		C(SYM_ADDR,		"sym-addr"),		\
1266 		C(VERBOSE,		"verbose"),		\
1267 		C(RAW,			"raw"),			\
1268 		C(HEX,			"hex"),			\
1269 		C(BIN,			"bin"),			\
1270 		C(BLOCK,		"block"),		\
1271 		C(PRINTK,		"trace_printk"),	\
1272 		C(ANNOTATE,		"annotate"),		\
1273 		C(USERSTACKTRACE,	"userstacktrace"),	\
1274 		C(SYM_USEROBJ,		"sym-userobj"),		\
1275 		C(PRINTK_MSGONLY,	"printk-msg-only"),	\
1276 		C(CONTEXT_INFO,		"context-info"),   /* Print pid/cpu/time */ \
1277 		C(LATENCY_FMT,		"latency-format"),	\
1278 		C(RECORD_CMD,		"record-cmd"),		\
1279 		C(RECORD_TGID,		"record-tgid"),		\
1280 		C(OVERWRITE,		"overwrite"),		\
1281 		C(STOP_ON_FREE,		"disable_on_free"),	\
1282 		C(IRQ_INFO,		"irq-info"),		\
1283 		C(MARKERS,		"markers"),		\
1284 		C(EVENT_FORK,		"event-fork"),		\
1285 		FUNCTION_FLAGS					\
1286 		FGRAPH_FLAGS					\
1287 		STACK_FLAGS					\
1288 		BRANCH_FLAGS
1289 
1290 /*
1291  * By defining C, we can make TRACE_FLAGS a list of bit names
1292  * that will define the bits for the flag masks.
1293  */
1294 #undef C
1295 #define C(a, b) TRACE_ITER_##a##_BIT
1296 
1297 enum trace_iterator_bits {
1298 	TRACE_FLAGS
1299 	/* Make sure we don't go more than we have bits for */
1300 	TRACE_ITER_LAST_BIT
1301 };
1302 
1303 /*
1304  * By redefining C, we can make TRACE_FLAGS a list of masks that
1305  * use the bits as defined above.
1306  */
1307 #undef C
1308 #define C(a, b) TRACE_ITER_##a = (1 << TRACE_ITER_##a##_BIT)
1309 
1310 enum trace_iterator_flags { TRACE_FLAGS };
1311 
1312 /*
1313  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
1314  * control the output of kernel symbols.
1315  */
1316 #define TRACE_ITER_SYM_MASK \
1317 	(TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
1318 
1319 extern struct tracer nop_trace;
1320 
1321 #ifdef CONFIG_BRANCH_TRACER
1322 extern int enable_branch_tracing(struct trace_array *tr);
1323 extern void disable_branch_tracing(void);
1324 static inline int trace_branch_enable(struct trace_array *tr)
1325 {
1326 	if (tr->trace_flags & TRACE_ITER_BRANCH)
1327 		return enable_branch_tracing(tr);
1328 	return 0;
1329 }
1330 static inline void trace_branch_disable(void)
1331 {
1332 	/* due to races, always disable */
1333 	disable_branch_tracing();
1334 }
1335 #else
1336 static inline int trace_branch_enable(struct trace_array *tr)
1337 {
1338 	return 0;
1339 }
1340 static inline void trace_branch_disable(void)
1341 {
1342 }
1343 #endif /* CONFIG_BRANCH_TRACER */
1344 
1345 /* set ring buffers to default size if not already done so */
1346 int tracing_update_buffers(void);
1347 
1348 struct ftrace_event_field {
1349 	struct list_head	link;
1350 	const char		*name;
1351 	const char		*type;
1352 	int			filter_type;
1353 	int			offset;
1354 	int			size;
1355 	int			is_signed;
1356 };
1357 
1358 struct prog_entry;
1359 
1360 struct event_filter {
1361 	struct prog_entry __rcu	*prog;
1362 	char			*filter_string;
1363 };
1364 
1365 struct event_subsystem {
1366 	struct list_head	list;
1367 	const char		*name;
1368 	struct event_filter	*filter;
1369 	int			ref_count;
1370 };
1371 
1372 struct trace_subsystem_dir {
1373 	struct list_head		list;
1374 	struct event_subsystem		*subsystem;
1375 	struct trace_array		*tr;
1376 	struct dentry			*entry;
1377 	int				ref_count;
1378 	int				nr_events;
1379 };
1380 
1381 extern int call_filter_check_discard(struct trace_event_call *call, void *rec,
1382 				     struct trace_buffer *buffer,
1383 				     struct ring_buffer_event *event);
1384 
1385 void trace_buffer_unlock_commit_regs(struct trace_array *tr,
1386 				     struct trace_buffer *buffer,
1387 				     struct ring_buffer_event *event,
1388 				     unsigned long flags, int pc,
1389 				     struct pt_regs *regs);
1390 
1391 static inline void trace_buffer_unlock_commit(struct trace_array *tr,
1392 					      struct trace_buffer *buffer,
1393 					      struct ring_buffer_event *event,
1394 					      unsigned long flags, int pc)
1395 {
1396 	trace_buffer_unlock_commit_regs(tr, buffer, event, flags, pc, NULL);
1397 }
1398 
1399 DECLARE_PER_CPU(struct ring_buffer_event *, trace_buffered_event);
1400 DECLARE_PER_CPU(int, trace_buffered_event_cnt);
1401 void trace_buffered_event_disable(void);
1402 void trace_buffered_event_enable(void);
1403 
1404 static inline void
1405 __trace_event_discard_commit(struct trace_buffer *buffer,
1406 			     struct ring_buffer_event *event)
1407 {
1408 	if (this_cpu_read(trace_buffered_event) == event) {
1409 		/* Simply release the temp buffer */
1410 		this_cpu_dec(trace_buffered_event_cnt);
1411 		return;
1412 	}
1413 	ring_buffer_discard_commit(buffer, event);
1414 }
1415 
1416 /*
1417  * Helper function for event_trigger_unlock_commit{_regs}().
1418  * If there are event triggers attached to this event that requires
1419  * filtering against its fields, then they wil be called as the
1420  * entry already holds the field information of the current event.
1421  *
1422  * It also checks if the event should be discarded or not.
1423  * It is to be discarded if the event is soft disabled and the
1424  * event was only recorded to process triggers, or if the event
1425  * filter is active and this event did not match the filters.
1426  *
1427  * Returns true if the event is discarded, false otherwise.
1428  */
1429 static inline bool
1430 __event_trigger_test_discard(struct trace_event_file *file,
1431 			     struct trace_buffer *buffer,
1432 			     struct ring_buffer_event *event,
1433 			     void *entry,
1434 			     enum event_trigger_type *tt)
1435 {
1436 	unsigned long eflags = file->flags;
1437 
1438 	if (eflags & EVENT_FILE_FL_TRIGGER_COND)
1439 		*tt = event_triggers_call(file, entry, event);
1440 
1441 	if (test_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags) ||
1442 	    (unlikely(file->flags & EVENT_FILE_FL_FILTERED) &&
1443 	     !filter_match_preds(file->filter, entry))) {
1444 		__trace_event_discard_commit(buffer, event);
1445 		return true;
1446 	}
1447 
1448 	return false;
1449 }
1450 
1451 /**
1452  * event_trigger_unlock_commit - handle triggers and finish event commit
1453  * @file: The file pointer assoctiated to the event
1454  * @buffer: The ring buffer that the event is being written to
1455  * @event: The event meta data in the ring buffer
1456  * @entry: The event itself
1457  * @irq_flags: The state of the interrupts at the start of the event
1458  * @pc: The state of the preempt count at the start of the event.
1459  *
1460  * This is a helper function to handle triggers that require data
1461  * from the event itself. It also tests the event against filters and
1462  * if the event is soft disabled and should be discarded.
1463  */
1464 static inline void
1465 event_trigger_unlock_commit(struct trace_event_file *file,
1466 			    struct trace_buffer *buffer,
1467 			    struct ring_buffer_event *event,
1468 			    void *entry, unsigned long irq_flags, int pc)
1469 {
1470 	enum event_trigger_type tt = ETT_NONE;
1471 
1472 	if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1473 		trace_buffer_unlock_commit(file->tr, buffer, event, irq_flags, pc);
1474 
1475 	if (tt)
1476 		event_triggers_post_call(file, tt);
1477 }
1478 
1479 /**
1480  * event_trigger_unlock_commit_regs - handle triggers and finish event commit
1481  * @file: The file pointer assoctiated to the event
1482  * @buffer: The ring buffer that the event is being written to
1483  * @event: The event meta data in the ring buffer
1484  * @entry: The event itself
1485  * @irq_flags: The state of the interrupts at the start of the event
1486  * @pc: The state of the preempt count at the start of the event.
1487  *
1488  * This is a helper function to handle triggers that require data
1489  * from the event itself. It also tests the event against filters and
1490  * if the event is soft disabled and should be discarded.
1491  *
1492  * Same as event_trigger_unlock_commit() but calls
1493  * trace_buffer_unlock_commit_regs() instead of trace_buffer_unlock_commit().
1494  */
1495 static inline void
1496 event_trigger_unlock_commit_regs(struct trace_event_file *file,
1497 				 struct trace_buffer *buffer,
1498 				 struct ring_buffer_event *event,
1499 				 void *entry, unsigned long irq_flags, int pc,
1500 				 struct pt_regs *regs)
1501 {
1502 	enum event_trigger_type tt = ETT_NONE;
1503 
1504 	if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1505 		trace_buffer_unlock_commit_regs(file->tr, buffer, event,
1506 						irq_flags, pc, regs);
1507 
1508 	if (tt)
1509 		event_triggers_post_call(file, tt);
1510 }
1511 
1512 #define FILTER_PRED_INVALID	((unsigned short)-1)
1513 #define FILTER_PRED_IS_RIGHT	(1 << 15)
1514 #define FILTER_PRED_FOLD	(1 << 15)
1515 
1516 /*
1517  * The max preds is the size of unsigned short with
1518  * two flags at the MSBs. One bit is used for both the IS_RIGHT
1519  * and FOLD flags. The other is reserved.
1520  *
1521  * 2^14 preds is way more than enough.
1522  */
1523 #define MAX_FILTER_PRED		16384
1524 
1525 struct filter_pred;
1526 struct regex;
1527 
1528 typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event);
1529 
1530 typedef int (*regex_match_func)(char *str, struct regex *r, int len);
1531 
1532 enum regex_type {
1533 	MATCH_FULL = 0,
1534 	MATCH_FRONT_ONLY,
1535 	MATCH_MIDDLE_ONLY,
1536 	MATCH_END_ONLY,
1537 	MATCH_GLOB,
1538 	MATCH_INDEX,
1539 };
1540 
1541 struct regex {
1542 	char			pattern[MAX_FILTER_STR_VAL];
1543 	int			len;
1544 	int			field_len;
1545 	regex_match_func	match;
1546 };
1547 
1548 struct filter_pred {
1549 	filter_pred_fn_t 	fn;
1550 	u64 			val;
1551 	struct regex		regex;
1552 	unsigned short		*ops;
1553 	struct ftrace_event_field *field;
1554 	int 			offset;
1555 	int			not;
1556 	int 			op;
1557 };
1558 
1559 static inline bool is_string_field(struct ftrace_event_field *field)
1560 {
1561 	return field->filter_type == FILTER_DYN_STRING ||
1562 	       field->filter_type == FILTER_STATIC_STRING ||
1563 	       field->filter_type == FILTER_PTR_STRING ||
1564 	       field->filter_type == FILTER_COMM;
1565 }
1566 
1567 static inline bool is_function_field(struct ftrace_event_field *field)
1568 {
1569 	return field->filter_type == FILTER_TRACE_FN;
1570 }
1571 
1572 extern enum regex_type
1573 filter_parse_regex(char *buff, int len, char **search, int *not);
1574 extern void print_event_filter(struct trace_event_file *file,
1575 			       struct trace_seq *s);
1576 extern int apply_event_filter(struct trace_event_file *file,
1577 			      char *filter_string);
1578 extern int apply_subsystem_event_filter(struct trace_subsystem_dir *dir,
1579 					char *filter_string);
1580 extern void print_subsystem_event_filter(struct event_subsystem *system,
1581 					 struct trace_seq *s);
1582 extern int filter_assign_type(const char *type);
1583 extern int create_event_filter(struct trace_array *tr,
1584 			       struct trace_event_call *call,
1585 			       char *filter_str, bool set_str,
1586 			       struct event_filter **filterp);
1587 extern void free_event_filter(struct event_filter *filter);
1588 
1589 struct ftrace_event_field *
1590 trace_find_event_field(struct trace_event_call *call, char *name);
1591 
1592 extern void trace_event_enable_cmd_record(bool enable);
1593 extern void trace_event_enable_tgid_record(bool enable);
1594 
1595 extern int event_trace_init(void);
1596 extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
1597 extern int event_trace_del_tracer(struct trace_array *tr);
1598 
1599 extern struct trace_event_file *__find_event_file(struct trace_array *tr,
1600 						  const char *system,
1601 						  const char *event);
1602 extern struct trace_event_file *find_event_file(struct trace_array *tr,
1603 						const char *system,
1604 						const char *event);
1605 
1606 static inline void *event_file_data(struct file *filp)
1607 {
1608 	return READ_ONCE(file_inode(filp)->i_private);
1609 }
1610 
1611 extern struct mutex event_mutex;
1612 extern struct list_head ftrace_events;
1613 
1614 extern const struct file_operations event_trigger_fops;
1615 extern const struct file_operations event_hist_fops;
1616 extern const struct file_operations event_inject_fops;
1617 
1618 #ifdef CONFIG_HIST_TRIGGERS
1619 extern int register_trigger_hist_cmd(void);
1620 extern int register_trigger_hist_enable_disable_cmds(void);
1621 #else
1622 static inline int register_trigger_hist_cmd(void) { return 0; }
1623 static inline int register_trigger_hist_enable_disable_cmds(void) { return 0; }
1624 #endif
1625 
1626 extern int register_trigger_cmds(void);
1627 extern void clear_event_triggers(struct trace_array *tr);
1628 
1629 struct event_trigger_data {
1630 	unsigned long			count;
1631 	int				ref;
1632 	struct event_trigger_ops	*ops;
1633 	struct event_command		*cmd_ops;
1634 	struct event_filter __rcu	*filter;
1635 	char				*filter_str;
1636 	void				*private_data;
1637 	bool				paused;
1638 	bool				paused_tmp;
1639 	struct list_head		list;
1640 	char				*name;
1641 	struct list_head		named_list;
1642 	struct event_trigger_data	*named_data;
1643 };
1644 
1645 /* Avoid typos */
1646 #define ENABLE_EVENT_STR	"enable_event"
1647 #define DISABLE_EVENT_STR	"disable_event"
1648 #define ENABLE_HIST_STR		"enable_hist"
1649 #define DISABLE_HIST_STR	"disable_hist"
1650 
1651 struct enable_trigger_data {
1652 	struct trace_event_file		*file;
1653 	bool				enable;
1654 	bool				hist;
1655 };
1656 
1657 extern int event_enable_trigger_print(struct seq_file *m,
1658 				      struct event_trigger_ops *ops,
1659 				      struct event_trigger_data *data);
1660 extern void event_enable_trigger_free(struct event_trigger_ops *ops,
1661 				      struct event_trigger_data *data);
1662 extern int event_enable_trigger_func(struct event_command *cmd_ops,
1663 				     struct trace_event_file *file,
1664 				     char *glob, char *cmd, char *param);
1665 extern int event_enable_register_trigger(char *glob,
1666 					 struct event_trigger_ops *ops,
1667 					 struct event_trigger_data *data,
1668 					 struct trace_event_file *file);
1669 extern void event_enable_unregister_trigger(char *glob,
1670 					    struct event_trigger_ops *ops,
1671 					    struct event_trigger_data *test,
1672 					    struct trace_event_file *file);
1673 extern void trigger_data_free(struct event_trigger_data *data);
1674 extern int event_trigger_init(struct event_trigger_ops *ops,
1675 			      struct event_trigger_data *data);
1676 extern int trace_event_trigger_enable_disable(struct trace_event_file *file,
1677 					      int trigger_enable);
1678 extern void update_cond_flag(struct trace_event_file *file);
1679 extern int set_trigger_filter(char *filter_str,
1680 			      struct event_trigger_data *trigger_data,
1681 			      struct trace_event_file *file);
1682 extern struct event_trigger_data *find_named_trigger(const char *name);
1683 extern bool is_named_trigger(struct event_trigger_data *test);
1684 extern int save_named_trigger(const char *name,
1685 			      struct event_trigger_data *data);
1686 extern void del_named_trigger(struct event_trigger_data *data);
1687 extern void pause_named_trigger(struct event_trigger_data *data);
1688 extern void unpause_named_trigger(struct event_trigger_data *data);
1689 extern void set_named_trigger_data(struct event_trigger_data *data,
1690 				   struct event_trigger_data *named_data);
1691 extern struct event_trigger_data *
1692 get_named_trigger_data(struct event_trigger_data *data);
1693 extern int register_event_command(struct event_command *cmd);
1694 extern int unregister_event_command(struct event_command *cmd);
1695 extern int register_trigger_hist_enable_disable_cmds(void);
1696 
1697 /**
1698  * struct event_trigger_ops - callbacks for trace event triggers
1699  *
1700  * The methods in this structure provide per-event trigger hooks for
1701  * various trigger operations.
1702  *
1703  * All the methods below, except for @init() and @free(), must be
1704  * implemented.
1705  *
1706  * @func: The trigger 'probe' function called when the triggering
1707  *	event occurs.  The data passed into this callback is the data
1708  *	that was supplied to the event_command @reg() function that
1709  *	registered the trigger (see struct event_command) along with
1710  *	the trace record, rec.
1711  *
1712  * @init: An optional initialization function called for the trigger
1713  *	when the trigger is registered (via the event_command reg()
1714  *	function).  This can be used to perform per-trigger
1715  *	initialization such as incrementing a per-trigger reference
1716  *	count, for instance.  This is usually implemented by the
1717  *	generic utility function @event_trigger_init() (see
1718  *	trace_event_triggers.c).
1719  *
1720  * @free: An optional de-initialization function called for the
1721  *	trigger when the trigger is unregistered (via the
1722  *	event_command @reg() function).  This can be used to perform
1723  *	per-trigger de-initialization such as decrementing a
1724  *	per-trigger reference count and freeing corresponding trigger
1725  *	data, for instance.  This is usually implemented by the
1726  *	generic utility function @event_trigger_free() (see
1727  *	trace_event_triggers.c).
1728  *
1729  * @print: The callback function invoked to have the trigger print
1730  *	itself.  This is usually implemented by a wrapper function
1731  *	that calls the generic utility function @event_trigger_print()
1732  *	(see trace_event_triggers.c).
1733  */
1734 struct event_trigger_ops {
1735 	void			(*func)(struct event_trigger_data *data,
1736 					void *rec,
1737 					struct ring_buffer_event *rbe);
1738 	int			(*init)(struct event_trigger_ops *ops,
1739 					struct event_trigger_data *data);
1740 	void			(*free)(struct event_trigger_ops *ops,
1741 					struct event_trigger_data *data);
1742 	int			(*print)(struct seq_file *m,
1743 					 struct event_trigger_ops *ops,
1744 					 struct event_trigger_data *data);
1745 };
1746 
1747 /**
1748  * struct event_command - callbacks and data members for event commands
1749  *
1750  * Event commands are invoked by users by writing the command name
1751  * into the 'trigger' file associated with a trace event.  The
1752  * parameters associated with a specific invocation of an event
1753  * command are used to create an event trigger instance, which is
1754  * added to the list of trigger instances associated with that trace
1755  * event.  When the event is hit, the set of triggers associated with
1756  * that event is invoked.
1757  *
1758  * The data members in this structure provide per-event command data
1759  * for various event commands.
1760  *
1761  * All the data members below, except for @post_trigger, must be set
1762  * for each event command.
1763  *
1764  * @name: The unique name that identifies the event command.  This is
1765  *	the name used when setting triggers via trigger files.
1766  *
1767  * @trigger_type: A unique id that identifies the event command
1768  *	'type'.  This value has two purposes, the first to ensure that
1769  *	only one trigger of the same type can be set at a given time
1770  *	for a particular event e.g. it doesn't make sense to have both
1771  *	a traceon and traceoff trigger attached to a single event at
1772  *	the same time, so traceon and traceoff have the same type
1773  *	though they have different names.  The @trigger_type value is
1774  *	also used as a bit value for deferring the actual trigger
1775  *	action until after the current event is finished.  Some
1776  *	commands need to do this if they themselves log to the trace
1777  *	buffer (see the @post_trigger() member below).  @trigger_type
1778  *	values are defined by adding new values to the trigger_type
1779  *	enum in include/linux/trace_events.h.
1780  *
1781  * @flags: See the enum event_command_flags below.
1782  *
1783  * All the methods below, except for @set_filter() and @unreg_all(),
1784  * must be implemented.
1785  *
1786  * @func: The callback function responsible for parsing and
1787  *	registering the trigger written to the 'trigger' file by the
1788  *	user.  It allocates the trigger instance and registers it with
1789  *	the appropriate trace event.  It makes use of the other
1790  *	event_command callback functions to orchestrate this, and is
1791  *	usually implemented by the generic utility function
1792  *	@event_trigger_callback() (see trace_event_triggers.c).
1793  *
1794  * @reg: Adds the trigger to the list of triggers associated with the
1795  *	event, and enables the event trigger itself, after
1796  *	initializing it (via the event_trigger_ops @init() function).
1797  *	This is also where commands can use the @trigger_type value to
1798  *	make the decision as to whether or not multiple instances of
1799  *	the trigger should be allowed.  This is usually implemented by
1800  *	the generic utility function @register_trigger() (see
1801  *	trace_event_triggers.c).
1802  *
1803  * @unreg: Removes the trigger from the list of triggers associated
1804  *	with the event, and disables the event trigger itself, after
1805  *	initializing it (via the event_trigger_ops @free() function).
1806  *	This is usually implemented by the generic utility function
1807  *	@unregister_trigger() (see trace_event_triggers.c).
1808  *
1809  * @unreg_all: An optional function called to remove all the triggers
1810  *	from the list of triggers associated with the event.  Called
1811  *	when a trigger file is opened in truncate mode.
1812  *
1813  * @set_filter: An optional function called to parse and set a filter
1814  *	for the trigger.  If no @set_filter() method is set for the
1815  *	event command, filters set by the user for the command will be
1816  *	ignored.  This is usually implemented by the generic utility
1817  *	function @set_trigger_filter() (see trace_event_triggers.c).
1818  *
1819  * @get_trigger_ops: The callback function invoked to retrieve the
1820  *	event_trigger_ops implementation associated with the command.
1821  */
1822 struct event_command {
1823 	struct list_head	list;
1824 	char			*name;
1825 	enum event_trigger_type	trigger_type;
1826 	int			flags;
1827 	int			(*func)(struct event_command *cmd_ops,
1828 					struct trace_event_file *file,
1829 					char *glob, char *cmd, char *params);
1830 	int			(*reg)(char *glob,
1831 				       struct event_trigger_ops *ops,
1832 				       struct event_trigger_data *data,
1833 				       struct trace_event_file *file);
1834 	void			(*unreg)(char *glob,
1835 					 struct event_trigger_ops *ops,
1836 					 struct event_trigger_data *data,
1837 					 struct trace_event_file *file);
1838 	void			(*unreg_all)(struct trace_event_file *file);
1839 	int			(*set_filter)(char *filter_str,
1840 					      struct event_trigger_data *data,
1841 					      struct trace_event_file *file);
1842 	struct event_trigger_ops *(*get_trigger_ops)(char *cmd, char *param);
1843 };
1844 
1845 /**
1846  * enum event_command_flags - flags for struct event_command
1847  *
1848  * @POST_TRIGGER: A flag that says whether or not this command needs
1849  *	to have its action delayed until after the current event has
1850  *	been closed.  Some triggers need to avoid being invoked while
1851  *	an event is currently in the process of being logged, since
1852  *	the trigger may itself log data into the trace buffer.  Thus
1853  *	we make sure the current event is committed before invoking
1854  *	those triggers.  To do that, the trigger invocation is split
1855  *	in two - the first part checks the filter using the current
1856  *	trace record; if a command has the @post_trigger flag set, it
1857  *	sets a bit for itself in the return value, otherwise it
1858  *	directly invokes the trigger.  Once all commands have been
1859  *	either invoked or set their return flag, the current record is
1860  *	either committed or discarded.  At that point, if any commands
1861  *	have deferred their triggers, those commands are finally
1862  *	invoked following the close of the current event.  In other
1863  *	words, if the event_trigger_ops @func() probe implementation
1864  *	itself logs to the trace buffer, this flag should be set,
1865  *	otherwise it can be left unspecified.
1866  *
1867  * @NEEDS_REC: A flag that says whether or not this command needs
1868  *	access to the trace record in order to perform its function,
1869  *	regardless of whether or not it has a filter associated with
1870  *	it (filters make a trigger require access to the trace record
1871  *	but are not always present).
1872  */
1873 enum event_command_flags {
1874 	EVENT_CMD_FL_POST_TRIGGER	= 1,
1875 	EVENT_CMD_FL_NEEDS_REC		= 2,
1876 };
1877 
1878 static inline bool event_command_post_trigger(struct event_command *cmd_ops)
1879 {
1880 	return cmd_ops->flags & EVENT_CMD_FL_POST_TRIGGER;
1881 }
1882 
1883 static inline bool event_command_needs_rec(struct event_command *cmd_ops)
1884 {
1885 	return cmd_ops->flags & EVENT_CMD_FL_NEEDS_REC;
1886 }
1887 
1888 extern int trace_event_enable_disable(struct trace_event_file *file,
1889 				      int enable, int soft_disable);
1890 extern int tracing_alloc_snapshot(void);
1891 extern void tracing_snapshot_cond(struct trace_array *tr, void *cond_data);
1892 extern int tracing_snapshot_cond_enable(struct trace_array *tr, void *cond_data, cond_update_fn_t update);
1893 
1894 extern int tracing_snapshot_cond_disable(struct trace_array *tr);
1895 extern void *tracing_cond_snapshot_data(struct trace_array *tr);
1896 
1897 extern const char *__start___trace_bprintk_fmt[];
1898 extern const char *__stop___trace_bprintk_fmt[];
1899 
1900 extern const char *__start___tracepoint_str[];
1901 extern const char *__stop___tracepoint_str[];
1902 
1903 void trace_printk_control(bool enabled);
1904 void trace_printk_start_comm(void);
1905 int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set);
1906 int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled);
1907 
1908 #define MAX_EVENT_NAME_LEN	64
1909 
1910 extern int trace_run_command(const char *buf, int (*createfn)(int, char**));
1911 extern ssize_t trace_parse_run_command(struct file *file,
1912 		const char __user *buffer, size_t count, loff_t *ppos,
1913 		int (*createfn)(int, char**));
1914 
1915 extern unsigned int err_pos(char *cmd, const char *str);
1916 extern void tracing_log_err(struct trace_array *tr,
1917 			    const char *loc, const char *cmd,
1918 			    const char **errs, u8 type, u8 pos);
1919 
1920 /*
1921  * Normal trace_printk() and friends allocates special buffers
1922  * to do the manipulation, as well as saves the print formats
1923  * into sections to display. But the trace infrastructure wants
1924  * to use these without the added overhead at the price of being
1925  * a bit slower (used mainly for warnings, where we don't care
1926  * about performance). The internal_trace_puts() is for such
1927  * a purpose.
1928  */
1929 #define internal_trace_puts(str) __trace_puts(_THIS_IP_, str, strlen(str))
1930 
1931 #undef FTRACE_ENTRY
1932 #define FTRACE_ENTRY(call, struct_name, id, tstruct, print, filter)	\
1933 	extern struct trace_event_call					\
1934 	__aligned(4) event_##call;
1935 #undef FTRACE_ENTRY_DUP
1936 #define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print, filter)	\
1937 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print), \
1938 		     filter)
1939 #undef FTRACE_ENTRY_PACKED
1940 #define FTRACE_ENTRY_PACKED(call, struct_name, id, tstruct, print, filter) \
1941 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print), \
1942 		     filter)
1943 
1944 #include "trace_entries.h"
1945 
1946 #if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_FUNCTION_TRACER)
1947 int perf_ftrace_event_register(struct trace_event_call *call,
1948 			       enum trace_reg type, void *data);
1949 #else
1950 #define perf_ftrace_event_register NULL
1951 #endif
1952 
1953 #ifdef CONFIG_FTRACE_SYSCALLS
1954 void init_ftrace_syscalls(void);
1955 const char *get_syscall_name(int syscall);
1956 #else
1957 static inline void init_ftrace_syscalls(void) { }
1958 static inline const char *get_syscall_name(int syscall)
1959 {
1960 	return NULL;
1961 }
1962 #endif
1963 
1964 #ifdef CONFIG_EVENT_TRACING
1965 void trace_event_init(void);
1966 void trace_event_eval_update(struct trace_eval_map **map, int len);
1967 #else
1968 static inline void __init trace_event_init(void) { }
1969 static inline void trace_event_eval_update(struct trace_eval_map **map, int len) { }
1970 #endif
1971 
1972 #ifdef CONFIG_TRACER_SNAPSHOT
1973 void tracing_snapshot_instance(struct trace_array *tr);
1974 int tracing_alloc_snapshot_instance(struct trace_array *tr);
1975 #else
1976 static inline void tracing_snapshot_instance(struct trace_array *tr) { }
1977 static inline int tracing_alloc_snapshot_instance(struct trace_array *tr)
1978 {
1979 	return 0;
1980 }
1981 #endif
1982 
1983 #ifdef CONFIG_PREEMPT_TRACER
1984 void tracer_preempt_on(unsigned long a0, unsigned long a1);
1985 void tracer_preempt_off(unsigned long a0, unsigned long a1);
1986 #else
1987 static inline void tracer_preempt_on(unsigned long a0, unsigned long a1) { }
1988 static inline void tracer_preempt_off(unsigned long a0, unsigned long a1) { }
1989 #endif
1990 #ifdef CONFIG_IRQSOFF_TRACER
1991 void tracer_hardirqs_on(unsigned long a0, unsigned long a1);
1992 void tracer_hardirqs_off(unsigned long a0, unsigned long a1);
1993 #else
1994 static inline void tracer_hardirqs_on(unsigned long a0, unsigned long a1) { }
1995 static inline void tracer_hardirqs_off(unsigned long a0, unsigned long a1) { }
1996 #endif
1997 
1998 extern struct trace_iterator *tracepoint_print_iter;
1999 
2000 /*
2001  * Reset the state of the trace_iterator so that it can read consumed data.
2002  * Normally, the trace_iterator is used for reading the data when it is not
2003  * consumed, and must retain state.
2004  */
2005 static __always_inline void trace_iterator_reset(struct trace_iterator *iter)
2006 {
2007 	const size_t offset = offsetof(struct trace_iterator, seq);
2008 
2009 	/*
2010 	 * Keep gcc from complaining about overwriting more than just one
2011 	 * member in the structure.
2012 	 */
2013 	memset((char *)iter + offset, 0, sizeof(struct trace_iterator) - offset);
2014 
2015 	iter->pos = -1;
2016 }
2017 
2018 #endif /* _LINUX_KERNEL_TRACE_H */
2019