xref: /openbmc/linux/kernel/trace/trace.h (revision dfe94d40)
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 #include <linux/ctype.h>
23 
24 #ifdef CONFIG_FTRACE_SYSCALLS
25 #include <asm/unistd.h>		/* For NR_SYSCALLS	     */
26 #include <asm/syscall.h>	/* some archs define it here */
27 #endif
28 
29 enum trace_type {
30 	__TRACE_FIRST_TYPE = 0,
31 
32 	TRACE_FN,
33 	TRACE_CTX,
34 	TRACE_WAKE,
35 	TRACE_STACK,
36 	TRACE_PRINT,
37 	TRACE_BPRINT,
38 	TRACE_MMIO_RW,
39 	TRACE_MMIO_MAP,
40 	TRACE_BRANCH,
41 	TRACE_GRAPH_RET,
42 	TRACE_GRAPH_ENT,
43 	TRACE_USER_STACK,
44 	TRACE_BLK,
45 	TRACE_BPUTS,
46 	TRACE_HWLAT,
47 	TRACE_RAW_DATA,
48 
49 	__TRACE_LAST_TYPE,
50 };
51 
52 
53 #undef __field
54 #define __field(type, item)		type	item;
55 
56 #undef __field_fn
57 #define __field_fn(type, item)		type	item;
58 
59 #undef __field_struct
60 #define __field_struct(type, item)	__field(type, item)
61 
62 #undef __field_desc
63 #define __field_desc(type, container, item)
64 
65 #undef __field_packed
66 #define __field_packed(type, container, item)
67 
68 #undef __array
69 #define __array(type, item, size)	type	item[size];
70 
71 #undef __array_desc
72 #define __array_desc(type, container, item, size)
73 
74 #undef __dynamic_array
75 #define __dynamic_array(type, item)	type	item[];
76 
77 #undef F_STRUCT
78 #define F_STRUCT(args...)		args
79 
80 #undef FTRACE_ENTRY
81 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print)		\
82 	struct struct_name {						\
83 		struct trace_entry	ent;				\
84 		tstruct							\
85 	}
86 
87 #undef FTRACE_ENTRY_DUP
88 #define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk)
89 
90 #undef FTRACE_ENTRY_REG
91 #define FTRACE_ENTRY_REG(name, struct_name, id, tstruct, print,	regfn)	\
92 	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print))
93 
94 #undef FTRACE_ENTRY_PACKED
95 #define FTRACE_ENTRY_PACKED(name, struct_name, id, tstruct, print)	\
96 	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print)) __packed
97 
98 #include "trace_entries.h"
99 
100 /* Use this for memory failure errors */
101 #define MEM_FAIL(condition, fmt, ...) ({			\
102 	static bool __section(".data.once") __warned;		\
103 	int __ret_warn_once = !!(condition);			\
104 								\
105 	if (unlikely(__ret_warn_once && !__warned)) {		\
106 		__warned = true;				\
107 		pr_err("ERROR: " fmt, ##__VA_ARGS__);		\
108 	}							\
109 	unlikely(__ret_warn_once);				\
110 })
111 
112 /*
113  * syscalls are special, and need special handling, this is why
114  * they are not included in trace_entries.h
115  */
116 struct syscall_trace_enter {
117 	struct trace_entry	ent;
118 	int			nr;
119 	unsigned long		args[];
120 };
121 
122 struct syscall_trace_exit {
123 	struct trace_entry	ent;
124 	int			nr;
125 	long			ret;
126 };
127 
128 struct kprobe_trace_entry_head {
129 	struct trace_entry	ent;
130 	unsigned long		ip;
131 };
132 
133 struct kretprobe_trace_entry_head {
134 	struct trace_entry	ent;
135 	unsigned long		func;
136 	unsigned long		ret_ip;
137 };
138 
139 /*
140  * trace_flag_type is an enumeration that holds different
141  * states when a trace occurs. These are:
142  *  IRQS_OFF		- interrupts were disabled
143  *  IRQS_NOSUPPORT	- arch does not support irqs_disabled_flags
144  *  NEED_RESCHED	- reschedule is requested
145  *  HARDIRQ		- inside an interrupt handler
146  *  SOFTIRQ		- inside a softirq handler
147  */
148 enum trace_flag_type {
149 	TRACE_FLAG_IRQS_OFF		= 0x01,
150 	TRACE_FLAG_IRQS_NOSUPPORT	= 0x02,
151 	TRACE_FLAG_NEED_RESCHED		= 0x04,
152 	TRACE_FLAG_HARDIRQ		= 0x08,
153 	TRACE_FLAG_SOFTIRQ		= 0x10,
154 	TRACE_FLAG_PREEMPT_RESCHED	= 0x20,
155 	TRACE_FLAG_NMI			= 0x40,
156 };
157 
158 #define TRACE_BUF_SIZE		1024
159 
160 struct trace_array;
161 
162 /*
163  * The CPU trace array - it consists of thousands of trace entries
164  * plus some other descriptor data: (for example which task started
165  * the trace, etc.)
166  */
167 struct trace_array_cpu {
168 	atomic_t		disabled;
169 	void			*buffer_page;	/* ring buffer spare */
170 
171 	unsigned long		entries;
172 	unsigned long		saved_latency;
173 	unsigned long		critical_start;
174 	unsigned long		critical_end;
175 	unsigned long		critical_sequence;
176 	unsigned long		nice;
177 	unsigned long		policy;
178 	unsigned long		rt_priority;
179 	unsigned long		skipped_entries;
180 	u64			preempt_timestamp;
181 	pid_t			pid;
182 	kuid_t			uid;
183 	char			comm[TASK_COMM_LEN];
184 
185 #ifdef CONFIG_FUNCTION_TRACER
186 	int			ftrace_ignore_pid;
187 #endif
188 	bool			ignore_pid;
189 };
190 
191 struct tracer;
192 struct trace_option_dentry;
193 
194 struct array_buffer {
195 	struct trace_array		*tr;
196 	struct trace_buffer		*buffer;
197 	struct trace_array_cpu __percpu	*data;
198 	u64				time_start;
199 	int				cpu;
200 };
201 
202 #define TRACE_FLAGS_MAX_SIZE		32
203 
204 struct trace_options {
205 	struct tracer			*tracer;
206 	struct trace_option_dentry	*topts;
207 };
208 
209 struct trace_pid_list {
210 	int				pid_max;
211 	unsigned long			*pids;
212 };
213 
214 enum {
215 	TRACE_PIDS		= BIT(0),
216 	TRACE_NO_PIDS		= BIT(1),
217 };
218 
219 static inline bool pid_type_enabled(int type, struct trace_pid_list *pid_list,
220 				    struct trace_pid_list *no_pid_list)
221 {
222 	/* Return true if the pid list in type has pids */
223 	return ((type & TRACE_PIDS) && pid_list) ||
224 		((type & TRACE_NO_PIDS) && no_pid_list);
225 }
226 
227 static inline bool still_need_pid_events(int type, struct trace_pid_list *pid_list,
228 					 struct trace_pid_list *no_pid_list)
229 {
230 	/*
231 	 * Turning off what is in @type, return true if the "other"
232 	 * pid list, still has pids in it.
233 	 */
234 	return (!(type & TRACE_PIDS) && pid_list) ||
235 		(!(type & TRACE_NO_PIDS) && no_pid_list);
236 }
237 
238 typedef bool (*cond_update_fn_t)(struct trace_array *tr, void *cond_data);
239 
240 /**
241  * struct cond_snapshot - conditional snapshot data and callback
242  *
243  * The cond_snapshot structure encapsulates a callback function and
244  * data associated with the snapshot for a given tracing instance.
245  *
246  * When a snapshot is taken conditionally, by invoking
247  * tracing_snapshot_cond(tr, cond_data), the cond_data passed in is
248  * passed in turn to the cond_snapshot.update() function.  That data
249  * can be compared by the update() implementation with the cond_data
250  * contained within the struct cond_snapshot instance associated with
251  * the trace_array.  Because the tr->max_lock is held throughout the
252  * update() call, the update() function can directly retrieve the
253  * cond_snapshot and cond_data associated with the per-instance
254  * snapshot associated with the trace_array.
255  *
256  * The cond_snapshot.update() implementation can save data to be
257  * associated with the snapshot if it decides to, and returns 'true'
258  * in that case, or it returns 'false' if the conditional snapshot
259  * shouldn't be taken.
260  *
261  * The cond_snapshot instance is created and associated with the
262  * user-defined cond_data by tracing_cond_snapshot_enable().
263  * Likewise, the cond_snapshot instance is destroyed and is no longer
264  * associated with the trace instance by
265  * tracing_cond_snapshot_disable().
266  *
267  * The method below is required.
268  *
269  * @update: When a conditional snapshot is invoked, the update()
270  *	callback function is invoked with the tr->max_lock held.  The
271  *	update() implementation signals whether or not to actually
272  *	take the snapshot, by returning 'true' if so, 'false' if no
273  *	snapshot should be taken.  Because the max_lock is held for
274  *	the duration of update(), the implementation is safe to
275  *	directly retrieved and save any implementation data it needs
276  *	to in association with the snapshot.
277  */
278 struct cond_snapshot {
279 	void				*cond_data;
280 	cond_update_fn_t		update;
281 };
282 
283 /*
284  * The trace array - an array of per-CPU trace arrays. This is the
285  * highest level data structure that individual tracers deal with.
286  * They have on/off state as well:
287  */
288 struct trace_array {
289 	struct list_head	list;
290 	char			*name;
291 	struct array_buffer	array_buffer;
292 #ifdef CONFIG_TRACER_MAX_TRACE
293 	/*
294 	 * The max_buffer is used to snapshot the trace when a maximum
295 	 * latency is reached, or when the user initiates a snapshot.
296 	 * Some tracers will use this to store a maximum trace while
297 	 * it continues examining live traces.
298 	 *
299 	 * The buffers for the max_buffer are set up the same as the array_buffer
300 	 * When a snapshot is taken, the buffer of the max_buffer is swapped
301 	 * with the buffer of the array_buffer and the buffers are reset for
302 	 * the array_buffer so the tracing can continue.
303 	 */
304 	struct array_buffer	max_buffer;
305 	bool			allocated_snapshot;
306 #endif
307 #if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)
308 	unsigned long		max_latency;
309 #ifdef CONFIG_FSNOTIFY
310 	struct dentry		*d_max_latency;
311 	struct work_struct	fsnotify_work;
312 	struct irq_work		fsnotify_irqwork;
313 #endif
314 #endif
315 	struct trace_pid_list	__rcu *filtered_pids;
316 	struct trace_pid_list	__rcu *filtered_no_pids;
317 	/*
318 	 * max_lock is used to protect the swapping of buffers
319 	 * when taking a max snapshot. The buffers themselves are
320 	 * protected by per_cpu spinlocks. But the action of the swap
321 	 * needs its own lock.
322 	 *
323 	 * This is defined as a arch_spinlock_t in order to help
324 	 * with performance when lockdep debugging is enabled.
325 	 *
326 	 * It is also used in other places outside the update_max_tr
327 	 * so it needs to be defined outside of the
328 	 * CONFIG_TRACER_MAX_TRACE.
329 	 */
330 	arch_spinlock_t		max_lock;
331 	int			buffer_disabled;
332 #ifdef CONFIG_FTRACE_SYSCALLS
333 	int			sys_refcount_enter;
334 	int			sys_refcount_exit;
335 	struct trace_event_file __rcu *enter_syscall_files[NR_syscalls];
336 	struct trace_event_file __rcu *exit_syscall_files[NR_syscalls];
337 #endif
338 	int			stop_count;
339 	int			clock_id;
340 	int			nr_topts;
341 	bool			clear_trace;
342 	int			buffer_percent;
343 	unsigned int		n_err_log_entries;
344 	struct tracer		*current_trace;
345 	unsigned int		trace_flags;
346 	unsigned char		trace_flags_index[TRACE_FLAGS_MAX_SIZE];
347 	unsigned int		flags;
348 	raw_spinlock_t		start_lock;
349 	struct list_head	err_log;
350 	struct dentry		*dir;
351 	struct dentry		*options;
352 	struct dentry		*percpu_dir;
353 	struct dentry		*event_dir;
354 	struct trace_options	*topts;
355 	struct list_head	systems;
356 	struct list_head	events;
357 	struct trace_event_file *trace_marker_file;
358 	cpumask_var_t		tracing_cpumask; /* only trace on set CPUs */
359 	int			ref;
360 	int			trace_ref;
361 #ifdef CONFIG_FUNCTION_TRACER
362 	struct ftrace_ops	*ops;
363 	struct trace_pid_list	__rcu *function_pids;
364 	struct trace_pid_list	__rcu *function_no_pids;
365 #ifdef CONFIG_DYNAMIC_FTRACE
366 	/* All of these are protected by the ftrace_lock */
367 	struct list_head	func_probes;
368 	struct list_head	mod_trace;
369 	struct list_head	mod_notrace;
370 #endif
371 	/* function tracing enabled */
372 	int			function_enabled;
373 #endif
374 	int			time_stamp_abs_ref;
375 	struct list_head	hist_vars;
376 #ifdef CONFIG_TRACER_SNAPSHOT
377 	struct cond_snapshot	*cond_snapshot;
378 #endif
379 };
380 
381 enum {
382 	TRACE_ARRAY_FL_GLOBAL	= (1 << 0)
383 };
384 
385 extern struct list_head ftrace_trace_arrays;
386 
387 extern struct mutex trace_types_lock;
388 
389 extern int trace_array_get(struct trace_array *tr);
390 extern int tracing_check_open_get_tr(struct trace_array *tr);
391 extern struct trace_array *trace_array_find(const char *instance);
392 extern struct trace_array *trace_array_find_get(const char *instance);
393 
394 extern int tracing_set_time_stamp_abs(struct trace_array *tr, bool abs);
395 extern int tracing_set_clock(struct trace_array *tr, const char *clockstr);
396 
397 extern bool trace_clock_in_ns(struct trace_array *tr);
398 
399 /*
400  * The global tracer (top) should be the first trace array added,
401  * but we check the flag anyway.
402  */
403 static inline struct trace_array *top_trace_array(void)
404 {
405 	struct trace_array *tr;
406 
407 	if (list_empty(&ftrace_trace_arrays))
408 		return NULL;
409 
410 	tr = list_entry(ftrace_trace_arrays.prev,
411 			typeof(*tr), list);
412 	WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
413 	return tr;
414 }
415 
416 #define FTRACE_CMP_TYPE(var, type) \
417 	__builtin_types_compatible_p(typeof(var), type *)
418 
419 #undef IF_ASSIGN
420 #define IF_ASSIGN(var, entry, etype, id)			\
421 	if (FTRACE_CMP_TYPE(var, etype)) {			\
422 		var = (typeof(var))(entry);			\
423 		WARN_ON(id != 0 && (entry)->type != id);	\
424 		break;						\
425 	}
426 
427 /* Will cause compile errors if type is not found. */
428 extern void __ftrace_bad_type(void);
429 
430 /*
431  * The trace_assign_type is a verifier that the entry type is
432  * the same as the type being assigned. To add new types simply
433  * add a line with the following format:
434  *
435  * IF_ASSIGN(var, ent, type, id);
436  *
437  *  Where "type" is the trace type that includes the trace_entry
438  *  as the "ent" item. And "id" is the trace identifier that is
439  *  used in the trace_type enum.
440  *
441  *  If the type can have more than one id, then use zero.
442  */
443 #define trace_assign_type(var, ent)					\
444 	do {								\
445 		IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);	\
446 		IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);	\
447 		IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);	\
448 		IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
449 		IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);	\
450 		IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT);	\
451 		IF_ASSIGN(var, ent, struct bputs_entry, TRACE_BPUTS);	\
452 		IF_ASSIGN(var, ent, struct hwlat_entry, TRACE_HWLAT);	\
453 		IF_ASSIGN(var, ent, struct raw_data_entry, TRACE_RAW_DATA);\
454 		IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,		\
455 			  TRACE_MMIO_RW);				\
456 		IF_ASSIGN(var, ent, struct trace_mmiotrace_map,		\
457 			  TRACE_MMIO_MAP);				\
458 		IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
459 		IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,	\
460 			  TRACE_GRAPH_ENT);		\
461 		IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,	\
462 			  TRACE_GRAPH_RET);		\
463 		__ftrace_bad_type();					\
464 	} while (0)
465 
466 /*
467  * An option specific to a tracer. This is a boolean value.
468  * The bit is the bit index that sets its value on the
469  * flags value in struct tracer_flags.
470  */
471 struct tracer_opt {
472 	const char	*name; /* Will appear on the trace_options file */
473 	u32		bit; /* Mask assigned in val field in tracer_flags */
474 };
475 
476 /*
477  * The set of specific options for a tracer. Your tracer
478  * have to set the initial value of the flags val.
479  */
480 struct tracer_flags {
481 	u32			val;
482 	struct tracer_opt	*opts;
483 	struct tracer		*trace;
484 };
485 
486 /* Makes more easy to define a tracer opt */
487 #define TRACER_OPT(s, b)	.name = #s, .bit = b
488 
489 
490 struct trace_option_dentry {
491 	struct tracer_opt		*opt;
492 	struct tracer_flags		*flags;
493 	struct trace_array		*tr;
494 	struct dentry			*entry;
495 };
496 
497 /**
498  * struct tracer - a specific tracer and its callbacks to interact with tracefs
499  * @name: the name chosen to select it on the available_tracers file
500  * @init: called when one switches to this tracer (echo name > current_tracer)
501  * @reset: called when one switches to another tracer
502  * @start: called when tracing is unpaused (echo 1 > tracing_on)
503  * @stop: called when tracing is paused (echo 0 > tracing_on)
504  * @update_thresh: called when tracing_thresh is updated
505  * @open: called when the trace file is opened
506  * @pipe_open: called when the trace_pipe file is opened
507  * @close: called when the trace file is released
508  * @pipe_close: called when the trace_pipe file is released
509  * @read: override the default read callback on trace_pipe
510  * @splice_read: override the default splice_read callback on trace_pipe
511  * @selftest: selftest to run on boot (see trace_selftest.c)
512  * @print_headers: override the first lines that describe your columns
513  * @print_line: callback that prints a trace
514  * @set_flag: signals one of your private flags changed (trace_options file)
515  * @flags: your private flags
516  */
517 struct tracer {
518 	const char		*name;
519 	int			(*init)(struct trace_array *tr);
520 	void			(*reset)(struct trace_array *tr);
521 	void			(*start)(struct trace_array *tr);
522 	void			(*stop)(struct trace_array *tr);
523 	int			(*update_thresh)(struct trace_array *tr);
524 	void			(*open)(struct trace_iterator *iter);
525 	void			(*pipe_open)(struct trace_iterator *iter);
526 	void			(*close)(struct trace_iterator *iter);
527 	void			(*pipe_close)(struct trace_iterator *iter);
528 	ssize_t			(*read)(struct trace_iterator *iter,
529 					struct file *filp, char __user *ubuf,
530 					size_t cnt, loff_t *ppos);
531 	ssize_t			(*splice_read)(struct trace_iterator *iter,
532 					       struct file *filp,
533 					       loff_t *ppos,
534 					       struct pipe_inode_info *pipe,
535 					       size_t len,
536 					       unsigned int flags);
537 #ifdef CONFIG_FTRACE_STARTUP_TEST
538 	int			(*selftest)(struct tracer *trace,
539 					    struct trace_array *tr);
540 #endif
541 	void			(*print_header)(struct seq_file *m);
542 	enum print_line_t	(*print_line)(struct trace_iterator *iter);
543 	/* If you handled the flag setting, return 0 */
544 	int			(*set_flag)(struct trace_array *tr,
545 					    u32 old_flags, u32 bit, int set);
546 	/* Return 0 if OK with change, else return non-zero */
547 	int			(*flag_changed)(struct trace_array *tr,
548 						u32 mask, int set);
549 	struct tracer		*next;
550 	struct tracer_flags	*flags;
551 	int			enabled;
552 	bool			print_max;
553 	bool			allow_instances;
554 #ifdef CONFIG_TRACER_MAX_TRACE
555 	bool			use_max_tr;
556 #endif
557 	/* True if tracer cannot be enabled in kernel param */
558 	bool			noboot;
559 };
560 
561 static inline struct ring_buffer_iter *
562 trace_buffer_iter(struct trace_iterator *iter, int cpu)
563 {
564 	return iter->buffer_iter ? iter->buffer_iter[cpu] : NULL;
565 }
566 
567 int tracer_init(struct tracer *t, struct trace_array *tr);
568 int tracing_is_enabled(void);
569 void tracing_reset_online_cpus(struct array_buffer *buf);
570 void tracing_reset_current(int cpu);
571 void tracing_reset_all_online_cpus(void);
572 int tracing_open_generic(struct inode *inode, struct file *filp);
573 int tracing_open_generic_tr(struct inode *inode, struct file *filp);
574 bool tracing_is_disabled(void);
575 bool tracer_tracing_is_on(struct trace_array *tr);
576 void tracer_tracing_on(struct trace_array *tr);
577 void tracer_tracing_off(struct trace_array *tr);
578 struct dentry *trace_create_file(const char *name,
579 				 umode_t mode,
580 				 struct dentry *parent,
581 				 void *data,
582 				 const struct file_operations *fops);
583 
584 int tracing_init_dentry(void);
585 
586 struct ring_buffer_event;
587 
588 struct ring_buffer_event *
589 trace_buffer_lock_reserve(struct trace_buffer *buffer,
590 			  int type,
591 			  unsigned long len,
592 			  unsigned long flags,
593 			  int pc);
594 
595 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
596 						struct trace_array_cpu *data);
597 
598 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
599 					  int *ent_cpu, u64 *ent_ts);
600 
601 void trace_buffer_unlock_commit_nostack(struct trace_buffer *buffer,
602 					struct ring_buffer_event *event);
603 
604 int trace_empty(struct trace_iterator *iter);
605 
606 void *trace_find_next_entry_inc(struct trace_iterator *iter);
607 
608 void trace_init_global_iter(struct trace_iterator *iter);
609 
610 void tracing_iter_reset(struct trace_iterator *iter, int cpu);
611 
612 unsigned long trace_total_entries_cpu(struct trace_array *tr, int cpu);
613 unsigned long trace_total_entries(struct trace_array *tr);
614 
615 void trace_function(struct trace_array *tr,
616 		    unsigned long ip,
617 		    unsigned long parent_ip,
618 		    unsigned long flags, int pc);
619 void trace_graph_function(struct trace_array *tr,
620 		    unsigned long ip,
621 		    unsigned long parent_ip,
622 		    unsigned long flags, int pc);
623 void trace_latency_header(struct seq_file *m);
624 void trace_default_header(struct seq_file *m);
625 void print_trace_header(struct seq_file *m, struct trace_iterator *iter);
626 int trace_empty(struct trace_iterator *iter);
627 
628 void trace_graph_return(struct ftrace_graph_ret *trace);
629 int trace_graph_entry(struct ftrace_graph_ent *trace);
630 void set_graph_array(struct trace_array *tr);
631 
632 void tracing_start_cmdline_record(void);
633 void tracing_stop_cmdline_record(void);
634 void tracing_start_tgid_record(void);
635 void tracing_stop_tgid_record(void);
636 
637 int register_tracer(struct tracer *type);
638 int is_tracing_stopped(void);
639 
640 loff_t tracing_lseek(struct file *file, loff_t offset, int whence);
641 
642 extern cpumask_var_t __read_mostly tracing_buffer_mask;
643 
644 #define for_each_tracing_cpu(cpu)	\
645 	for_each_cpu(cpu, tracing_buffer_mask)
646 
647 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
648 
649 extern unsigned long tracing_thresh;
650 
651 /* PID filtering */
652 
653 extern int pid_max;
654 
655 bool trace_find_filtered_pid(struct trace_pid_list *filtered_pids,
656 			     pid_t search_pid);
657 bool trace_ignore_this_task(struct trace_pid_list *filtered_pids,
658 			    struct trace_pid_list *filtered_no_pids,
659 			    struct task_struct *task);
660 void trace_filter_add_remove_task(struct trace_pid_list *pid_list,
661 				  struct task_struct *self,
662 				  struct task_struct *task);
663 void *trace_pid_next(struct trace_pid_list *pid_list, void *v, loff_t *pos);
664 void *trace_pid_start(struct trace_pid_list *pid_list, loff_t *pos);
665 int trace_pid_show(struct seq_file *m, void *v);
666 void trace_free_pid_list(struct trace_pid_list *pid_list);
667 int trace_pid_write(struct trace_pid_list *filtered_pids,
668 		    struct trace_pid_list **new_pid_list,
669 		    const char __user *ubuf, size_t cnt);
670 
671 #ifdef CONFIG_TRACER_MAX_TRACE
672 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu,
673 		   void *cond_data);
674 void update_max_tr_single(struct trace_array *tr,
675 			  struct task_struct *tsk, int cpu);
676 #endif /* CONFIG_TRACER_MAX_TRACE */
677 
678 #if (defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)) && \
679 	defined(CONFIG_FSNOTIFY)
680 
681 void latency_fsnotify(struct trace_array *tr);
682 
683 #else
684 
685 static inline void latency_fsnotify(struct trace_array *tr) { }
686 
687 #endif
688 
689 #ifdef CONFIG_STACKTRACE
690 void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
691 		   int pc);
692 #else
693 static inline void __trace_stack(struct trace_array *tr, unsigned long flags,
694 				 int skip, int pc)
695 {
696 }
697 #endif /* CONFIG_STACKTRACE */
698 
699 extern u64 ftrace_now(int cpu);
700 
701 extern void trace_find_cmdline(int pid, char comm[]);
702 extern int trace_find_tgid(int pid);
703 extern void trace_event_follow_fork(struct trace_array *tr, bool enable);
704 
705 #ifdef CONFIG_DYNAMIC_FTRACE
706 extern unsigned long ftrace_update_tot_cnt;
707 extern unsigned long ftrace_number_of_pages;
708 extern unsigned long ftrace_number_of_groups;
709 void ftrace_init_trace_array(struct trace_array *tr);
710 #else
711 static inline void ftrace_init_trace_array(struct trace_array *tr) { }
712 #endif
713 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
714 extern int DYN_FTRACE_TEST_NAME(void);
715 #define DYN_FTRACE_TEST_NAME2 trace_selftest_dynamic_test_func2
716 extern int DYN_FTRACE_TEST_NAME2(void);
717 
718 extern bool ring_buffer_expanded;
719 extern bool tracing_selftest_disabled;
720 
721 #ifdef CONFIG_FTRACE_STARTUP_TEST
722 extern void __init disable_tracing_selftest(const char *reason);
723 
724 extern int trace_selftest_startup_function(struct tracer *trace,
725 					   struct trace_array *tr);
726 extern int trace_selftest_startup_function_graph(struct tracer *trace,
727 						 struct trace_array *tr);
728 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
729 					  struct trace_array *tr);
730 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
731 					     struct trace_array *tr);
732 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
733 						 struct trace_array *tr);
734 extern int trace_selftest_startup_wakeup(struct tracer *trace,
735 					 struct trace_array *tr);
736 extern int trace_selftest_startup_nop(struct tracer *trace,
737 					 struct trace_array *tr);
738 extern int trace_selftest_startup_branch(struct tracer *trace,
739 					 struct trace_array *tr);
740 /*
741  * Tracer data references selftest functions that only occur
742  * on boot up. These can be __init functions. Thus, when selftests
743  * are enabled, then the tracers need to reference __init functions.
744  */
745 #define __tracer_data		__refdata
746 #else
747 static inline void __init disable_tracing_selftest(const char *reason)
748 {
749 }
750 /* Tracers are seldom changed. Optimize when selftests are disabled. */
751 #define __tracer_data		__read_mostly
752 #endif /* CONFIG_FTRACE_STARTUP_TEST */
753 
754 extern void *head_page(struct trace_array_cpu *data);
755 extern unsigned long long ns2usecs(u64 nsec);
756 extern int
757 trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
758 extern int
759 trace_vprintk(unsigned long ip, const char *fmt, va_list args);
760 extern int
761 trace_array_vprintk(struct trace_array *tr,
762 		    unsigned long ip, const char *fmt, va_list args);
763 int trace_array_printk_buf(struct trace_buffer *buffer,
764 			   unsigned long ip, const char *fmt, ...);
765 void trace_printk_seq(struct trace_seq *s);
766 enum print_line_t print_trace_line(struct trace_iterator *iter);
767 
768 extern char trace_find_mark(unsigned long long duration);
769 
770 struct ftrace_hash;
771 
772 struct ftrace_mod_load {
773 	struct list_head	list;
774 	char			*func;
775 	char			*module;
776 	int			 enable;
777 };
778 
779 enum {
780 	FTRACE_HASH_FL_MOD	= (1 << 0),
781 };
782 
783 struct ftrace_hash {
784 	unsigned long		size_bits;
785 	struct hlist_head	*buckets;
786 	unsigned long		count;
787 	unsigned long		flags;
788 	struct rcu_head		rcu;
789 };
790 
791 struct ftrace_func_entry *
792 ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip);
793 
794 static __always_inline bool ftrace_hash_empty(struct ftrace_hash *hash)
795 {
796 	return !hash || !(hash->count || (hash->flags & FTRACE_HASH_FL_MOD));
797 }
798 
799 /* Standard output formatting function used for function return traces */
800 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
801 
802 /* Flag options */
803 #define TRACE_GRAPH_PRINT_OVERRUN       0x1
804 #define TRACE_GRAPH_PRINT_CPU           0x2
805 #define TRACE_GRAPH_PRINT_OVERHEAD      0x4
806 #define TRACE_GRAPH_PRINT_PROC          0x8
807 #define TRACE_GRAPH_PRINT_DURATION      0x10
808 #define TRACE_GRAPH_PRINT_ABS_TIME      0x20
809 #define TRACE_GRAPH_PRINT_REL_TIME      0x40
810 #define TRACE_GRAPH_PRINT_IRQS          0x80
811 #define TRACE_GRAPH_PRINT_TAIL          0x100
812 #define TRACE_GRAPH_SLEEP_TIME          0x200
813 #define TRACE_GRAPH_GRAPH_TIME          0x400
814 #define TRACE_GRAPH_PRINT_FILL_SHIFT	28
815 #define TRACE_GRAPH_PRINT_FILL_MASK	(0x3 << TRACE_GRAPH_PRINT_FILL_SHIFT)
816 
817 extern void ftrace_graph_sleep_time_control(bool enable);
818 
819 #ifdef CONFIG_FUNCTION_PROFILER
820 extern void ftrace_graph_graph_time_control(bool enable);
821 #else
822 static inline void ftrace_graph_graph_time_control(bool enable) { }
823 #endif
824 
825 extern enum print_line_t
826 print_graph_function_flags(struct trace_iterator *iter, u32 flags);
827 extern void print_graph_headers_flags(struct seq_file *s, u32 flags);
828 extern void
829 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
830 extern void graph_trace_open(struct trace_iterator *iter);
831 extern void graph_trace_close(struct trace_iterator *iter);
832 extern int __trace_graph_entry(struct trace_array *tr,
833 			       struct ftrace_graph_ent *trace,
834 			       unsigned long flags, int pc);
835 extern void __trace_graph_return(struct trace_array *tr,
836 				 struct ftrace_graph_ret *trace,
837 				 unsigned long flags, int pc);
838 
839 #ifdef CONFIG_DYNAMIC_FTRACE
840 extern struct ftrace_hash __rcu *ftrace_graph_hash;
841 extern struct ftrace_hash __rcu *ftrace_graph_notrace_hash;
842 
843 static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace)
844 {
845 	unsigned long addr = trace->func;
846 	int ret = 0;
847 	struct ftrace_hash *hash;
848 
849 	preempt_disable_notrace();
850 
851 	/*
852 	 * Have to open code "rcu_dereference_sched()" because the
853 	 * function graph tracer can be called when RCU is not
854 	 * "watching".
855 	 * Protected with schedule_on_each_cpu(ftrace_sync)
856 	 */
857 	hash = rcu_dereference_protected(ftrace_graph_hash, !preemptible());
858 
859 	if (ftrace_hash_empty(hash)) {
860 		ret = 1;
861 		goto out;
862 	}
863 
864 	if (ftrace_lookup_ip(hash, addr)) {
865 
866 		/*
867 		 * This needs to be cleared on the return functions
868 		 * when the depth is zero.
869 		 */
870 		trace_recursion_set(TRACE_GRAPH_BIT);
871 		trace_recursion_set_depth(trace->depth);
872 
873 		/*
874 		 * If no irqs are to be traced, but a set_graph_function
875 		 * is set, and called by an interrupt handler, we still
876 		 * want to trace it.
877 		 */
878 		if (in_irq())
879 			trace_recursion_set(TRACE_IRQ_BIT);
880 		else
881 			trace_recursion_clear(TRACE_IRQ_BIT);
882 		ret = 1;
883 	}
884 
885 out:
886 	preempt_enable_notrace();
887 	return ret;
888 }
889 
890 static inline void ftrace_graph_addr_finish(struct ftrace_graph_ret *trace)
891 {
892 	if (trace_recursion_test(TRACE_GRAPH_BIT) &&
893 	    trace->depth == trace_recursion_depth())
894 		trace_recursion_clear(TRACE_GRAPH_BIT);
895 }
896 
897 static inline int ftrace_graph_notrace_addr(unsigned long addr)
898 {
899 	int ret = 0;
900 	struct ftrace_hash *notrace_hash;
901 
902 	preempt_disable_notrace();
903 
904 	/*
905 	 * Have to open code "rcu_dereference_sched()" because the
906 	 * function graph tracer can be called when RCU is not
907 	 * "watching".
908 	 * Protected with schedule_on_each_cpu(ftrace_sync)
909 	 */
910 	notrace_hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
911 						 !preemptible());
912 
913 	if (ftrace_lookup_ip(notrace_hash, addr))
914 		ret = 1;
915 
916 	preempt_enable_notrace();
917 	return ret;
918 }
919 #else
920 static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace)
921 {
922 	return 1;
923 }
924 
925 static inline int ftrace_graph_notrace_addr(unsigned long addr)
926 {
927 	return 0;
928 }
929 static inline void ftrace_graph_addr_finish(struct ftrace_graph_ret *trace)
930 { }
931 #endif /* CONFIG_DYNAMIC_FTRACE */
932 
933 extern unsigned int fgraph_max_depth;
934 
935 static inline bool ftrace_graph_ignore_func(struct ftrace_graph_ent *trace)
936 {
937 	/* trace it when it is-nested-in or is a function enabled. */
938 	return !(trace_recursion_test(TRACE_GRAPH_BIT) ||
939 		 ftrace_graph_addr(trace)) ||
940 		(trace->depth < 0) ||
941 		(fgraph_max_depth && trace->depth >= fgraph_max_depth);
942 }
943 
944 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
945 static inline enum print_line_t
946 print_graph_function_flags(struct trace_iterator *iter, u32 flags)
947 {
948 	return TRACE_TYPE_UNHANDLED;
949 }
950 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
951 
952 extern struct list_head ftrace_pids;
953 
954 #ifdef CONFIG_FUNCTION_TRACER
955 
956 #define FTRACE_PID_IGNORE	-1
957 #define FTRACE_PID_TRACE	-2
958 
959 struct ftrace_func_command {
960 	struct list_head	list;
961 	char			*name;
962 	int			(*func)(struct trace_array *tr,
963 					struct ftrace_hash *hash,
964 					char *func, char *cmd,
965 					char *params, int enable);
966 };
967 extern bool ftrace_filter_param __initdata;
968 static inline int ftrace_trace_task(struct trace_array *tr)
969 {
970 	return this_cpu_read(tr->array_buffer.data->ftrace_ignore_pid) !=
971 		FTRACE_PID_IGNORE;
972 }
973 extern int ftrace_is_dead(void);
974 int ftrace_create_function_files(struct trace_array *tr,
975 				 struct dentry *parent);
976 void ftrace_destroy_function_files(struct trace_array *tr);
977 int ftrace_allocate_ftrace_ops(struct trace_array *tr);
978 void ftrace_free_ftrace_ops(struct trace_array *tr);
979 void ftrace_init_global_array_ops(struct trace_array *tr);
980 void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func);
981 void ftrace_reset_array_ops(struct trace_array *tr);
982 void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer);
983 void ftrace_init_tracefs_toplevel(struct trace_array *tr,
984 				  struct dentry *d_tracer);
985 void ftrace_clear_pids(struct trace_array *tr);
986 int init_function_trace(void);
987 void ftrace_pid_follow_fork(struct trace_array *tr, bool enable);
988 #else
989 static inline int ftrace_trace_task(struct trace_array *tr)
990 {
991 	return 1;
992 }
993 static inline int ftrace_is_dead(void) { return 0; }
994 static inline int
995 ftrace_create_function_files(struct trace_array *tr,
996 			     struct dentry *parent)
997 {
998 	return 0;
999 }
1000 static inline int ftrace_allocate_ftrace_ops(struct trace_array *tr)
1001 {
1002 	return 0;
1003 }
1004 static inline void ftrace_free_ftrace_ops(struct trace_array *tr) { }
1005 static inline void ftrace_destroy_function_files(struct trace_array *tr) { }
1006 static inline __init void
1007 ftrace_init_global_array_ops(struct trace_array *tr) { }
1008 static inline void ftrace_reset_array_ops(struct trace_array *tr) { }
1009 static inline void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d) { }
1010 static inline void ftrace_init_tracefs_toplevel(struct trace_array *tr, struct dentry *d) { }
1011 static inline void ftrace_clear_pids(struct trace_array *tr) { }
1012 static inline int init_function_trace(void) { return 0; }
1013 static inline void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) { }
1014 /* ftace_func_t type is not defined, use macro instead of static inline */
1015 #define ftrace_init_array_ops(tr, func) do { } while (0)
1016 #endif /* CONFIG_FUNCTION_TRACER */
1017 
1018 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
1019 
1020 struct ftrace_probe_ops {
1021 	void			(*func)(unsigned long ip,
1022 					unsigned long parent_ip,
1023 					struct trace_array *tr,
1024 					struct ftrace_probe_ops *ops,
1025 					void *data);
1026 	int			(*init)(struct ftrace_probe_ops *ops,
1027 					struct trace_array *tr,
1028 					unsigned long ip, void *init_data,
1029 					void **data);
1030 	void			(*free)(struct ftrace_probe_ops *ops,
1031 					struct trace_array *tr,
1032 					unsigned long ip, void *data);
1033 	int			(*print)(struct seq_file *m,
1034 					 unsigned long ip,
1035 					 struct ftrace_probe_ops *ops,
1036 					 void *data);
1037 };
1038 
1039 struct ftrace_func_mapper;
1040 typedef int (*ftrace_mapper_func)(void *data);
1041 
1042 struct ftrace_func_mapper *allocate_ftrace_func_mapper(void);
1043 void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
1044 					   unsigned long ip);
1045 int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
1046 			       unsigned long ip, void *data);
1047 void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
1048 				   unsigned long ip);
1049 void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
1050 			     ftrace_mapper_func free_func);
1051 
1052 extern int
1053 register_ftrace_function_probe(char *glob, struct trace_array *tr,
1054 			       struct ftrace_probe_ops *ops, void *data);
1055 extern int
1056 unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
1057 				      struct ftrace_probe_ops *ops);
1058 extern void clear_ftrace_function_probes(struct trace_array *tr);
1059 
1060 int register_ftrace_command(struct ftrace_func_command *cmd);
1061 int unregister_ftrace_command(struct ftrace_func_command *cmd);
1062 
1063 void ftrace_create_filter_files(struct ftrace_ops *ops,
1064 				struct dentry *parent);
1065 void ftrace_destroy_filter_files(struct ftrace_ops *ops);
1066 
1067 extern int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
1068 			     int len, int reset);
1069 extern int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
1070 			      int len, int reset);
1071 #else
1072 struct ftrace_func_command;
1073 
1074 static inline __init int register_ftrace_command(struct ftrace_func_command *cmd)
1075 {
1076 	return -EINVAL;
1077 }
1078 static inline __init int unregister_ftrace_command(char *cmd_name)
1079 {
1080 	return -EINVAL;
1081 }
1082 static inline void clear_ftrace_function_probes(struct trace_array *tr)
1083 {
1084 }
1085 
1086 /*
1087  * The ops parameter passed in is usually undefined.
1088  * This must be a macro.
1089  */
1090 #define ftrace_create_filter_files(ops, parent) do { } while (0)
1091 #define ftrace_destroy_filter_files(ops) do { } while (0)
1092 #endif /* CONFIG_FUNCTION_TRACER && CONFIG_DYNAMIC_FTRACE */
1093 
1094 bool ftrace_event_is_function(struct trace_event_call *call);
1095 
1096 /*
1097  * struct trace_parser - servers for reading the user input separated by spaces
1098  * @cont: set if the input is not complete - no final space char was found
1099  * @buffer: holds the parsed user input
1100  * @idx: user input length
1101  * @size: buffer size
1102  */
1103 struct trace_parser {
1104 	bool		cont;
1105 	char		*buffer;
1106 	unsigned	idx;
1107 	unsigned	size;
1108 };
1109 
1110 static inline bool trace_parser_loaded(struct trace_parser *parser)
1111 {
1112 	return (parser->idx != 0);
1113 }
1114 
1115 static inline bool trace_parser_cont(struct trace_parser *parser)
1116 {
1117 	return parser->cont;
1118 }
1119 
1120 static inline void trace_parser_clear(struct trace_parser *parser)
1121 {
1122 	parser->cont = false;
1123 	parser->idx = 0;
1124 }
1125 
1126 extern int trace_parser_get_init(struct trace_parser *parser, int size);
1127 extern void trace_parser_put(struct trace_parser *parser);
1128 extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
1129 	size_t cnt, loff_t *ppos);
1130 
1131 /*
1132  * Only create function graph options if function graph is configured.
1133  */
1134 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1135 # define FGRAPH_FLAGS						\
1136 		C(DISPLAY_GRAPH,	"display-graph"),
1137 #else
1138 # define FGRAPH_FLAGS
1139 #endif
1140 
1141 #ifdef CONFIG_BRANCH_TRACER
1142 # define BRANCH_FLAGS					\
1143 		C(BRANCH,		"branch"),
1144 #else
1145 # define BRANCH_FLAGS
1146 #endif
1147 
1148 #ifdef CONFIG_FUNCTION_TRACER
1149 # define FUNCTION_FLAGS						\
1150 		C(FUNCTION,		"function-trace"),	\
1151 		C(FUNC_FORK,		"function-fork"),
1152 # define FUNCTION_DEFAULT_FLAGS		TRACE_ITER_FUNCTION
1153 #else
1154 # define FUNCTION_FLAGS
1155 # define FUNCTION_DEFAULT_FLAGS		0UL
1156 # define TRACE_ITER_FUNC_FORK		0UL
1157 #endif
1158 
1159 #ifdef CONFIG_STACKTRACE
1160 # define STACK_FLAGS				\
1161 		C(STACKTRACE,		"stacktrace"),
1162 #else
1163 # define STACK_FLAGS
1164 #endif
1165 
1166 /*
1167  * trace_iterator_flags is an enumeration that defines bit
1168  * positions into trace_flags that controls the output.
1169  *
1170  * NOTE: These bits must match the trace_options array in
1171  *       trace.c (this macro guarantees it).
1172  */
1173 #define TRACE_FLAGS						\
1174 		C(PRINT_PARENT,		"print-parent"),	\
1175 		C(SYM_OFFSET,		"sym-offset"),		\
1176 		C(SYM_ADDR,		"sym-addr"),		\
1177 		C(VERBOSE,		"verbose"),		\
1178 		C(RAW,			"raw"),			\
1179 		C(HEX,			"hex"),			\
1180 		C(BIN,			"bin"),			\
1181 		C(BLOCK,		"block"),		\
1182 		C(PRINTK,		"trace_printk"),	\
1183 		C(ANNOTATE,		"annotate"),		\
1184 		C(USERSTACKTRACE,	"userstacktrace"),	\
1185 		C(SYM_USEROBJ,		"sym-userobj"),		\
1186 		C(PRINTK_MSGONLY,	"printk-msg-only"),	\
1187 		C(CONTEXT_INFO,		"context-info"),   /* Print pid/cpu/time */ \
1188 		C(LATENCY_FMT,		"latency-format"),	\
1189 		C(RECORD_CMD,		"record-cmd"),		\
1190 		C(RECORD_TGID,		"record-tgid"),		\
1191 		C(OVERWRITE,		"overwrite"),		\
1192 		C(STOP_ON_FREE,		"disable_on_free"),	\
1193 		C(IRQ_INFO,		"irq-info"),		\
1194 		C(MARKERS,		"markers"),		\
1195 		C(EVENT_FORK,		"event-fork"),		\
1196 		C(PAUSE_ON_TRACE,	"pause-on-trace"),	\
1197 		FUNCTION_FLAGS					\
1198 		FGRAPH_FLAGS					\
1199 		STACK_FLAGS					\
1200 		BRANCH_FLAGS
1201 
1202 /*
1203  * By defining C, we can make TRACE_FLAGS a list of bit names
1204  * that will define the bits for the flag masks.
1205  */
1206 #undef C
1207 #define C(a, b) TRACE_ITER_##a##_BIT
1208 
1209 enum trace_iterator_bits {
1210 	TRACE_FLAGS
1211 	/* Make sure we don't go more than we have bits for */
1212 	TRACE_ITER_LAST_BIT
1213 };
1214 
1215 /*
1216  * By redefining C, we can make TRACE_FLAGS a list of masks that
1217  * use the bits as defined above.
1218  */
1219 #undef C
1220 #define C(a, b) TRACE_ITER_##a = (1 << TRACE_ITER_##a##_BIT)
1221 
1222 enum trace_iterator_flags { TRACE_FLAGS };
1223 
1224 /*
1225  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
1226  * control the output of kernel symbols.
1227  */
1228 #define TRACE_ITER_SYM_MASK \
1229 	(TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
1230 
1231 extern struct tracer nop_trace;
1232 
1233 #ifdef CONFIG_BRANCH_TRACER
1234 extern int enable_branch_tracing(struct trace_array *tr);
1235 extern void disable_branch_tracing(void);
1236 static inline int trace_branch_enable(struct trace_array *tr)
1237 {
1238 	if (tr->trace_flags & TRACE_ITER_BRANCH)
1239 		return enable_branch_tracing(tr);
1240 	return 0;
1241 }
1242 static inline void trace_branch_disable(void)
1243 {
1244 	/* due to races, always disable */
1245 	disable_branch_tracing();
1246 }
1247 #else
1248 static inline int trace_branch_enable(struct trace_array *tr)
1249 {
1250 	return 0;
1251 }
1252 static inline void trace_branch_disable(void)
1253 {
1254 }
1255 #endif /* CONFIG_BRANCH_TRACER */
1256 
1257 /* set ring buffers to default size if not already done so */
1258 int tracing_update_buffers(void);
1259 
1260 struct ftrace_event_field {
1261 	struct list_head	link;
1262 	const char		*name;
1263 	const char		*type;
1264 	int			filter_type;
1265 	int			offset;
1266 	int			size;
1267 	int			is_signed;
1268 };
1269 
1270 struct prog_entry;
1271 
1272 struct event_filter {
1273 	struct prog_entry __rcu	*prog;
1274 	char			*filter_string;
1275 };
1276 
1277 struct event_subsystem {
1278 	struct list_head	list;
1279 	const char		*name;
1280 	struct event_filter	*filter;
1281 	int			ref_count;
1282 };
1283 
1284 struct trace_subsystem_dir {
1285 	struct list_head		list;
1286 	struct event_subsystem		*subsystem;
1287 	struct trace_array		*tr;
1288 	struct dentry			*entry;
1289 	int				ref_count;
1290 	int				nr_events;
1291 };
1292 
1293 extern int call_filter_check_discard(struct trace_event_call *call, void *rec,
1294 				     struct trace_buffer *buffer,
1295 				     struct ring_buffer_event *event);
1296 
1297 void trace_buffer_unlock_commit_regs(struct trace_array *tr,
1298 				     struct trace_buffer *buffer,
1299 				     struct ring_buffer_event *event,
1300 				     unsigned long flags, int pc,
1301 				     struct pt_regs *regs);
1302 
1303 static inline void trace_buffer_unlock_commit(struct trace_array *tr,
1304 					      struct trace_buffer *buffer,
1305 					      struct ring_buffer_event *event,
1306 					      unsigned long flags, int pc)
1307 {
1308 	trace_buffer_unlock_commit_regs(tr, buffer, event, flags, pc, NULL);
1309 }
1310 
1311 DECLARE_PER_CPU(struct ring_buffer_event *, trace_buffered_event);
1312 DECLARE_PER_CPU(int, trace_buffered_event_cnt);
1313 void trace_buffered_event_disable(void);
1314 void trace_buffered_event_enable(void);
1315 
1316 static inline void
1317 __trace_event_discard_commit(struct trace_buffer *buffer,
1318 			     struct ring_buffer_event *event)
1319 {
1320 	if (this_cpu_read(trace_buffered_event) == event) {
1321 		/* Simply release the temp buffer */
1322 		this_cpu_dec(trace_buffered_event_cnt);
1323 		return;
1324 	}
1325 	ring_buffer_discard_commit(buffer, event);
1326 }
1327 
1328 /*
1329  * Helper function for event_trigger_unlock_commit{_regs}().
1330  * If there are event triggers attached to this event that requires
1331  * filtering against its fields, then they will be called as the
1332  * entry already holds the field information of the current event.
1333  *
1334  * It also checks if the event should be discarded or not.
1335  * It is to be discarded if the event is soft disabled and the
1336  * event was only recorded to process triggers, or if the event
1337  * filter is active and this event did not match the filters.
1338  *
1339  * Returns true if the event is discarded, false otherwise.
1340  */
1341 static inline bool
1342 __event_trigger_test_discard(struct trace_event_file *file,
1343 			     struct trace_buffer *buffer,
1344 			     struct ring_buffer_event *event,
1345 			     void *entry,
1346 			     enum event_trigger_type *tt)
1347 {
1348 	unsigned long eflags = file->flags;
1349 
1350 	if (eflags & EVENT_FILE_FL_TRIGGER_COND)
1351 		*tt = event_triggers_call(file, entry, event);
1352 
1353 	if (test_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags) ||
1354 	    (unlikely(file->flags & EVENT_FILE_FL_FILTERED) &&
1355 	     !filter_match_preds(file->filter, entry))) {
1356 		__trace_event_discard_commit(buffer, event);
1357 		return true;
1358 	}
1359 
1360 	return false;
1361 }
1362 
1363 /**
1364  * event_trigger_unlock_commit - handle triggers and finish event commit
1365  * @file: The file pointer assoctiated to the event
1366  * @buffer: The ring buffer that the event is being written to
1367  * @event: The event meta data in the ring buffer
1368  * @entry: The event itself
1369  * @irq_flags: The state of the interrupts at the start of the event
1370  * @pc: The state of the preempt count at the start of the event.
1371  *
1372  * This is a helper function to handle triggers that require data
1373  * from the event itself. It also tests the event against filters and
1374  * if the event is soft disabled and should be discarded.
1375  */
1376 static inline void
1377 event_trigger_unlock_commit(struct trace_event_file *file,
1378 			    struct trace_buffer *buffer,
1379 			    struct ring_buffer_event *event,
1380 			    void *entry, unsigned long irq_flags, int pc)
1381 {
1382 	enum event_trigger_type tt = ETT_NONE;
1383 
1384 	if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1385 		trace_buffer_unlock_commit(file->tr, buffer, event, irq_flags, pc);
1386 
1387 	if (tt)
1388 		event_triggers_post_call(file, tt);
1389 }
1390 
1391 /**
1392  * event_trigger_unlock_commit_regs - handle triggers and finish event commit
1393  * @file: The file pointer assoctiated to the event
1394  * @buffer: The ring buffer that the event is being written to
1395  * @event: The event meta data in the ring buffer
1396  * @entry: The event itself
1397  * @irq_flags: The state of the interrupts at the start of the event
1398  * @pc: The state of the preempt count at the start of the event.
1399  *
1400  * This is a helper function to handle triggers that require data
1401  * from the event itself. It also tests the event against filters and
1402  * if the event is soft disabled and should be discarded.
1403  *
1404  * Same as event_trigger_unlock_commit() but calls
1405  * trace_buffer_unlock_commit_regs() instead of trace_buffer_unlock_commit().
1406  */
1407 static inline void
1408 event_trigger_unlock_commit_regs(struct trace_event_file *file,
1409 				 struct trace_buffer *buffer,
1410 				 struct ring_buffer_event *event,
1411 				 void *entry, unsigned long irq_flags, int pc,
1412 				 struct pt_regs *regs)
1413 {
1414 	enum event_trigger_type tt = ETT_NONE;
1415 
1416 	if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1417 		trace_buffer_unlock_commit_regs(file->tr, buffer, event,
1418 						irq_flags, pc, regs);
1419 
1420 	if (tt)
1421 		event_triggers_post_call(file, tt);
1422 }
1423 
1424 #define FILTER_PRED_INVALID	((unsigned short)-1)
1425 #define FILTER_PRED_IS_RIGHT	(1 << 15)
1426 #define FILTER_PRED_FOLD	(1 << 15)
1427 
1428 /*
1429  * The max preds is the size of unsigned short with
1430  * two flags at the MSBs. One bit is used for both the IS_RIGHT
1431  * and FOLD flags. The other is reserved.
1432  *
1433  * 2^14 preds is way more than enough.
1434  */
1435 #define MAX_FILTER_PRED		16384
1436 
1437 struct filter_pred;
1438 struct regex;
1439 
1440 typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event);
1441 
1442 typedef int (*regex_match_func)(char *str, struct regex *r, int len);
1443 
1444 enum regex_type {
1445 	MATCH_FULL = 0,
1446 	MATCH_FRONT_ONLY,
1447 	MATCH_MIDDLE_ONLY,
1448 	MATCH_END_ONLY,
1449 	MATCH_GLOB,
1450 	MATCH_INDEX,
1451 };
1452 
1453 struct regex {
1454 	char			pattern[MAX_FILTER_STR_VAL];
1455 	int			len;
1456 	int			field_len;
1457 	regex_match_func	match;
1458 };
1459 
1460 struct filter_pred {
1461 	filter_pred_fn_t 	fn;
1462 	u64 			val;
1463 	struct regex		regex;
1464 	unsigned short		*ops;
1465 	struct ftrace_event_field *field;
1466 	int 			offset;
1467 	int			not;
1468 	int 			op;
1469 };
1470 
1471 static inline bool is_string_field(struct ftrace_event_field *field)
1472 {
1473 	return field->filter_type == FILTER_DYN_STRING ||
1474 	       field->filter_type == FILTER_STATIC_STRING ||
1475 	       field->filter_type == FILTER_PTR_STRING ||
1476 	       field->filter_type == FILTER_COMM;
1477 }
1478 
1479 static inline bool is_function_field(struct ftrace_event_field *field)
1480 {
1481 	return field->filter_type == FILTER_TRACE_FN;
1482 }
1483 
1484 extern enum regex_type
1485 filter_parse_regex(char *buff, int len, char **search, int *not);
1486 extern void print_event_filter(struct trace_event_file *file,
1487 			       struct trace_seq *s);
1488 extern int apply_event_filter(struct trace_event_file *file,
1489 			      char *filter_string);
1490 extern int apply_subsystem_event_filter(struct trace_subsystem_dir *dir,
1491 					char *filter_string);
1492 extern void print_subsystem_event_filter(struct event_subsystem *system,
1493 					 struct trace_seq *s);
1494 extern int filter_assign_type(const char *type);
1495 extern int create_event_filter(struct trace_array *tr,
1496 			       struct trace_event_call *call,
1497 			       char *filter_str, bool set_str,
1498 			       struct event_filter **filterp);
1499 extern void free_event_filter(struct event_filter *filter);
1500 
1501 struct ftrace_event_field *
1502 trace_find_event_field(struct trace_event_call *call, char *name);
1503 
1504 extern void trace_event_enable_cmd_record(bool enable);
1505 extern void trace_event_enable_tgid_record(bool enable);
1506 
1507 extern int event_trace_init(void);
1508 extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
1509 extern int event_trace_del_tracer(struct trace_array *tr);
1510 extern void __trace_early_add_events(struct trace_array *tr);
1511 
1512 extern struct trace_event_file *__find_event_file(struct trace_array *tr,
1513 						  const char *system,
1514 						  const char *event);
1515 extern struct trace_event_file *find_event_file(struct trace_array *tr,
1516 						const char *system,
1517 						const char *event);
1518 
1519 static inline void *event_file_data(struct file *filp)
1520 {
1521 	return READ_ONCE(file_inode(filp)->i_private);
1522 }
1523 
1524 extern struct mutex event_mutex;
1525 extern struct list_head ftrace_events;
1526 
1527 extern const struct file_operations event_trigger_fops;
1528 extern const struct file_operations event_hist_fops;
1529 extern const struct file_operations event_hist_debug_fops;
1530 extern const struct file_operations event_inject_fops;
1531 
1532 #ifdef CONFIG_HIST_TRIGGERS
1533 extern int register_trigger_hist_cmd(void);
1534 extern int register_trigger_hist_enable_disable_cmds(void);
1535 #else
1536 static inline int register_trigger_hist_cmd(void) { return 0; }
1537 static inline int register_trigger_hist_enable_disable_cmds(void) { return 0; }
1538 #endif
1539 
1540 extern int register_trigger_cmds(void);
1541 extern void clear_event_triggers(struct trace_array *tr);
1542 
1543 struct event_trigger_data {
1544 	unsigned long			count;
1545 	int				ref;
1546 	struct event_trigger_ops	*ops;
1547 	struct event_command		*cmd_ops;
1548 	struct event_filter __rcu	*filter;
1549 	char				*filter_str;
1550 	void				*private_data;
1551 	bool				paused;
1552 	bool				paused_tmp;
1553 	struct list_head		list;
1554 	char				*name;
1555 	struct list_head		named_list;
1556 	struct event_trigger_data	*named_data;
1557 };
1558 
1559 /* Avoid typos */
1560 #define ENABLE_EVENT_STR	"enable_event"
1561 #define DISABLE_EVENT_STR	"disable_event"
1562 #define ENABLE_HIST_STR		"enable_hist"
1563 #define DISABLE_HIST_STR	"disable_hist"
1564 
1565 struct enable_trigger_data {
1566 	struct trace_event_file		*file;
1567 	bool				enable;
1568 	bool				hist;
1569 };
1570 
1571 extern int event_enable_trigger_print(struct seq_file *m,
1572 				      struct event_trigger_ops *ops,
1573 				      struct event_trigger_data *data);
1574 extern void event_enable_trigger_free(struct event_trigger_ops *ops,
1575 				      struct event_trigger_data *data);
1576 extern int event_enable_trigger_func(struct event_command *cmd_ops,
1577 				     struct trace_event_file *file,
1578 				     char *glob, char *cmd, char *param);
1579 extern int event_enable_register_trigger(char *glob,
1580 					 struct event_trigger_ops *ops,
1581 					 struct event_trigger_data *data,
1582 					 struct trace_event_file *file);
1583 extern void event_enable_unregister_trigger(char *glob,
1584 					    struct event_trigger_ops *ops,
1585 					    struct event_trigger_data *test,
1586 					    struct trace_event_file *file);
1587 extern void trigger_data_free(struct event_trigger_data *data);
1588 extern int event_trigger_init(struct event_trigger_ops *ops,
1589 			      struct event_trigger_data *data);
1590 extern int trace_event_trigger_enable_disable(struct trace_event_file *file,
1591 					      int trigger_enable);
1592 extern void update_cond_flag(struct trace_event_file *file);
1593 extern int set_trigger_filter(char *filter_str,
1594 			      struct event_trigger_data *trigger_data,
1595 			      struct trace_event_file *file);
1596 extern struct event_trigger_data *find_named_trigger(const char *name);
1597 extern bool is_named_trigger(struct event_trigger_data *test);
1598 extern int save_named_trigger(const char *name,
1599 			      struct event_trigger_data *data);
1600 extern void del_named_trigger(struct event_trigger_data *data);
1601 extern void pause_named_trigger(struct event_trigger_data *data);
1602 extern void unpause_named_trigger(struct event_trigger_data *data);
1603 extern void set_named_trigger_data(struct event_trigger_data *data,
1604 				   struct event_trigger_data *named_data);
1605 extern struct event_trigger_data *
1606 get_named_trigger_data(struct event_trigger_data *data);
1607 extern int register_event_command(struct event_command *cmd);
1608 extern int unregister_event_command(struct event_command *cmd);
1609 extern int register_trigger_hist_enable_disable_cmds(void);
1610 
1611 /**
1612  * struct event_trigger_ops - callbacks for trace event triggers
1613  *
1614  * The methods in this structure provide per-event trigger hooks for
1615  * various trigger operations.
1616  *
1617  * All the methods below, except for @init() and @free(), must be
1618  * implemented.
1619  *
1620  * @func: The trigger 'probe' function called when the triggering
1621  *	event occurs.  The data passed into this callback is the data
1622  *	that was supplied to the event_command @reg() function that
1623  *	registered the trigger (see struct event_command) along with
1624  *	the trace record, rec.
1625  *
1626  * @init: An optional initialization function called for the trigger
1627  *	when the trigger is registered (via the event_command reg()
1628  *	function).  This can be used to perform per-trigger
1629  *	initialization such as incrementing a per-trigger reference
1630  *	count, for instance.  This is usually implemented by the
1631  *	generic utility function @event_trigger_init() (see
1632  *	trace_event_triggers.c).
1633  *
1634  * @free: An optional de-initialization function called for the
1635  *	trigger when the trigger is unregistered (via the
1636  *	event_command @reg() function).  This can be used to perform
1637  *	per-trigger de-initialization such as decrementing a
1638  *	per-trigger reference count and freeing corresponding trigger
1639  *	data, for instance.  This is usually implemented by the
1640  *	generic utility function @event_trigger_free() (see
1641  *	trace_event_triggers.c).
1642  *
1643  * @print: The callback function invoked to have the trigger print
1644  *	itself.  This is usually implemented by a wrapper function
1645  *	that calls the generic utility function @event_trigger_print()
1646  *	(see trace_event_triggers.c).
1647  */
1648 struct event_trigger_ops {
1649 	void			(*func)(struct event_trigger_data *data,
1650 					void *rec,
1651 					struct ring_buffer_event *rbe);
1652 	int			(*init)(struct event_trigger_ops *ops,
1653 					struct event_trigger_data *data);
1654 	void			(*free)(struct event_trigger_ops *ops,
1655 					struct event_trigger_data *data);
1656 	int			(*print)(struct seq_file *m,
1657 					 struct event_trigger_ops *ops,
1658 					 struct event_trigger_data *data);
1659 };
1660 
1661 /**
1662  * struct event_command - callbacks and data members for event commands
1663  *
1664  * Event commands are invoked by users by writing the command name
1665  * into the 'trigger' file associated with a trace event.  The
1666  * parameters associated with a specific invocation of an event
1667  * command are used to create an event trigger instance, which is
1668  * added to the list of trigger instances associated with that trace
1669  * event.  When the event is hit, the set of triggers associated with
1670  * that event is invoked.
1671  *
1672  * The data members in this structure provide per-event command data
1673  * for various event commands.
1674  *
1675  * All the data members below, except for @post_trigger, must be set
1676  * for each event command.
1677  *
1678  * @name: The unique name that identifies the event command.  This is
1679  *	the name used when setting triggers via trigger files.
1680  *
1681  * @trigger_type: A unique id that identifies the event command
1682  *	'type'.  This value has two purposes, the first to ensure that
1683  *	only one trigger of the same type can be set at a given time
1684  *	for a particular event e.g. it doesn't make sense to have both
1685  *	a traceon and traceoff trigger attached to a single event at
1686  *	the same time, so traceon and traceoff have the same type
1687  *	though they have different names.  The @trigger_type value is
1688  *	also used as a bit value for deferring the actual trigger
1689  *	action until after the current event is finished.  Some
1690  *	commands need to do this if they themselves log to the trace
1691  *	buffer (see the @post_trigger() member below).  @trigger_type
1692  *	values are defined by adding new values to the trigger_type
1693  *	enum in include/linux/trace_events.h.
1694  *
1695  * @flags: See the enum event_command_flags below.
1696  *
1697  * All the methods below, except for @set_filter() and @unreg_all(),
1698  * must be implemented.
1699  *
1700  * @func: The callback function responsible for parsing and
1701  *	registering the trigger written to the 'trigger' file by the
1702  *	user.  It allocates the trigger instance and registers it with
1703  *	the appropriate trace event.  It makes use of the other
1704  *	event_command callback functions to orchestrate this, and is
1705  *	usually implemented by the generic utility function
1706  *	@event_trigger_callback() (see trace_event_triggers.c).
1707  *
1708  * @reg: Adds the trigger to the list of triggers associated with the
1709  *	event, and enables the event trigger itself, after
1710  *	initializing it (via the event_trigger_ops @init() function).
1711  *	This is also where commands can use the @trigger_type value to
1712  *	make the decision as to whether or not multiple instances of
1713  *	the trigger should be allowed.  This is usually implemented by
1714  *	the generic utility function @register_trigger() (see
1715  *	trace_event_triggers.c).
1716  *
1717  * @unreg: Removes the trigger from the list of triggers associated
1718  *	with the event, and disables the event trigger itself, after
1719  *	initializing it (via the event_trigger_ops @free() function).
1720  *	This is usually implemented by the generic utility function
1721  *	@unregister_trigger() (see trace_event_triggers.c).
1722  *
1723  * @unreg_all: An optional function called to remove all the triggers
1724  *	from the list of triggers associated with the event.  Called
1725  *	when a trigger file is opened in truncate mode.
1726  *
1727  * @set_filter: An optional function called to parse and set a filter
1728  *	for the trigger.  If no @set_filter() method is set for the
1729  *	event command, filters set by the user for the command will be
1730  *	ignored.  This is usually implemented by the generic utility
1731  *	function @set_trigger_filter() (see trace_event_triggers.c).
1732  *
1733  * @get_trigger_ops: The callback function invoked to retrieve the
1734  *	event_trigger_ops implementation associated with the command.
1735  */
1736 struct event_command {
1737 	struct list_head	list;
1738 	char			*name;
1739 	enum event_trigger_type	trigger_type;
1740 	int			flags;
1741 	int			(*func)(struct event_command *cmd_ops,
1742 					struct trace_event_file *file,
1743 					char *glob, char *cmd, char *params);
1744 	int			(*reg)(char *glob,
1745 				       struct event_trigger_ops *ops,
1746 				       struct event_trigger_data *data,
1747 				       struct trace_event_file *file);
1748 	void			(*unreg)(char *glob,
1749 					 struct event_trigger_ops *ops,
1750 					 struct event_trigger_data *data,
1751 					 struct trace_event_file *file);
1752 	void			(*unreg_all)(struct trace_event_file *file);
1753 	int			(*set_filter)(char *filter_str,
1754 					      struct event_trigger_data *data,
1755 					      struct trace_event_file *file);
1756 	struct event_trigger_ops *(*get_trigger_ops)(char *cmd, char *param);
1757 };
1758 
1759 /**
1760  * enum event_command_flags - flags for struct event_command
1761  *
1762  * @POST_TRIGGER: A flag that says whether or not this command needs
1763  *	to have its action delayed until after the current event has
1764  *	been closed.  Some triggers need to avoid being invoked while
1765  *	an event is currently in the process of being logged, since
1766  *	the trigger may itself log data into the trace buffer.  Thus
1767  *	we make sure the current event is committed before invoking
1768  *	those triggers.  To do that, the trigger invocation is split
1769  *	in two - the first part checks the filter using the current
1770  *	trace record; if a command has the @post_trigger flag set, it
1771  *	sets a bit for itself in the return value, otherwise it
1772  *	directly invokes the trigger.  Once all commands have been
1773  *	either invoked or set their return flag, the current record is
1774  *	either committed or discarded.  At that point, if any commands
1775  *	have deferred their triggers, those commands are finally
1776  *	invoked following the close of the current event.  In other
1777  *	words, if the event_trigger_ops @func() probe implementation
1778  *	itself logs to the trace buffer, this flag should be set,
1779  *	otherwise it can be left unspecified.
1780  *
1781  * @NEEDS_REC: A flag that says whether or not this command needs
1782  *	access to the trace record in order to perform its function,
1783  *	regardless of whether or not it has a filter associated with
1784  *	it (filters make a trigger require access to the trace record
1785  *	but are not always present).
1786  */
1787 enum event_command_flags {
1788 	EVENT_CMD_FL_POST_TRIGGER	= 1,
1789 	EVENT_CMD_FL_NEEDS_REC		= 2,
1790 };
1791 
1792 static inline bool event_command_post_trigger(struct event_command *cmd_ops)
1793 {
1794 	return cmd_ops->flags & EVENT_CMD_FL_POST_TRIGGER;
1795 }
1796 
1797 static inline bool event_command_needs_rec(struct event_command *cmd_ops)
1798 {
1799 	return cmd_ops->flags & EVENT_CMD_FL_NEEDS_REC;
1800 }
1801 
1802 extern int trace_event_enable_disable(struct trace_event_file *file,
1803 				      int enable, int soft_disable);
1804 extern int tracing_alloc_snapshot(void);
1805 extern void tracing_snapshot_cond(struct trace_array *tr, void *cond_data);
1806 extern int tracing_snapshot_cond_enable(struct trace_array *tr, void *cond_data, cond_update_fn_t update);
1807 
1808 extern int tracing_snapshot_cond_disable(struct trace_array *tr);
1809 extern void *tracing_cond_snapshot_data(struct trace_array *tr);
1810 
1811 extern const char *__start___trace_bprintk_fmt[];
1812 extern const char *__stop___trace_bprintk_fmt[];
1813 
1814 extern const char *__start___tracepoint_str[];
1815 extern const char *__stop___tracepoint_str[];
1816 
1817 void trace_printk_control(bool enabled);
1818 void trace_printk_start_comm(void);
1819 int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set);
1820 int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled);
1821 
1822 /* Used from boot time tracer */
1823 extern int trace_set_options(struct trace_array *tr, char *option);
1824 extern int tracing_set_tracer(struct trace_array *tr, const char *buf);
1825 extern ssize_t tracing_resize_ring_buffer(struct trace_array *tr,
1826 					  unsigned long size, int cpu_id);
1827 extern int tracing_set_cpumask(struct trace_array *tr,
1828 				cpumask_var_t tracing_cpumask_new);
1829 
1830 
1831 #define MAX_EVENT_NAME_LEN	64
1832 
1833 extern int trace_run_command(const char *buf, int (*createfn)(int, char**));
1834 extern ssize_t trace_parse_run_command(struct file *file,
1835 		const char __user *buffer, size_t count, loff_t *ppos,
1836 		int (*createfn)(int, char**));
1837 
1838 extern unsigned int err_pos(char *cmd, const char *str);
1839 extern void tracing_log_err(struct trace_array *tr,
1840 			    const char *loc, const char *cmd,
1841 			    const char **errs, u8 type, u8 pos);
1842 
1843 /*
1844  * Normal trace_printk() and friends allocates special buffers
1845  * to do the manipulation, as well as saves the print formats
1846  * into sections to display. But the trace infrastructure wants
1847  * to use these without the added overhead at the price of being
1848  * a bit slower (used mainly for warnings, where we don't care
1849  * about performance). The internal_trace_puts() is for such
1850  * a purpose.
1851  */
1852 #define internal_trace_puts(str) __trace_puts(_THIS_IP_, str, strlen(str))
1853 
1854 #undef FTRACE_ENTRY
1855 #define FTRACE_ENTRY(call, struct_name, id, tstruct, print)	\
1856 	extern struct trace_event_call					\
1857 	__aligned(4) event_##call;
1858 #undef FTRACE_ENTRY_DUP
1859 #define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print)	\
1860 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
1861 #undef FTRACE_ENTRY_PACKED
1862 #define FTRACE_ENTRY_PACKED(call, struct_name, id, tstruct, print) \
1863 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
1864 
1865 #include "trace_entries.h"
1866 
1867 #if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_FUNCTION_TRACER)
1868 int perf_ftrace_event_register(struct trace_event_call *call,
1869 			       enum trace_reg type, void *data);
1870 #else
1871 #define perf_ftrace_event_register NULL
1872 #endif
1873 
1874 #ifdef CONFIG_FTRACE_SYSCALLS
1875 void init_ftrace_syscalls(void);
1876 const char *get_syscall_name(int syscall);
1877 #else
1878 static inline void init_ftrace_syscalls(void) { }
1879 static inline const char *get_syscall_name(int syscall)
1880 {
1881 	return NULL;
1882 }
1883 #endif
1884 
1885 #ifdef CONFIG_EVENT_TRACING
1886 void trace_event_init(void);
1887 void trace_event_eval_update(struct trace_eval_map **map, int len);
1888 /* Used from boot time tracer */
1889 extern int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set);
1890 extern int trigger_process_regex(struct trace_event_file *file, char *buff);
1891 #else
1892 static inline void __init trace_event_init(void) { }
1893 static inline void trace_event_eval_update(struct trace_eval_map **map, int len) { }
1894 #endif
1895 
1896 #ifdef CONFIG_TRACER_SNAPSHOT
1897 void tracing_snapshot_instance(struct trace_array *tr);
1898 int tracing_alloc_snapshot_instance(struct trace_array *tr);
1899 #else
1900 static inline void tracing_snapshot_instance(struct trace_array *tr) { }
1901 static inline int tracing_alloc_snapshot_instance(struct trace_array *tr)
1902 {
1903 	return 0;
1904 }
1905 #endif
1906 
1907 #ifdef CONFIG_PREEMPT_TRACER
1908 void tracer_preempt_on(unsigned long a0, unsigned long a1);
1909 void tracer_preempt_off(unsigned long a0, unsigned long a1);
1910 #else
1911 static inline void tracer_preempt_on(unsigned long a0, unsigned long a1) { }
1912 static inline void tracer_preempt_off(unsigned long a0, unsigned long a1) { }
1913 #endif
1914 #ifdef CONFIG_IRQSOFF_TRACER
1915 void tracer_hardirqs_on(unsigned long a0, unsigned long a1);
1916 void tracer_hardirqs_off(unsigned long a0, unsigned long a1);
1917 #else
1918 static inline void tracer_hardirqs_on(unsigned long a0, unsigned long a1) { }
1919 static inline void tracer_hardirqs_off(unsigned long a0, unsigned long a1) { }
1920 #endif
1921 
1922 extern struct trace_iterator *tracepoint_print_iter;
1923 
1924 /*
1925  * Reset the state of the trace_iterator so that it can read consumed data.
1926  * Normally, the trace_iterator is used for reading the data when it is not
1927  * consumed, and must retain state.
1928  */
1929 static __always_inline void trace_iterator_reset(struct trace_iterator *iter)
1930 {
1931 	const size_t offset = offsetof(struct trace_iterator, seq);
1932 
1933 	/*
1934 	 * Keep gcc from complaining about overwriting more than just one
1935 	 * member in the structure.
1936 	 */
1937 	memset((char *)iter + offset, 0, sizeof(struct trace_iterator) - offset);
1938 
1939 	iter->pos = -1;
1940 }
1941 
1942 /* Check the name is good for event/group/fields */
1943 static inline bool is_good_name(const char *name)
1944 {
1945 	if (!isalpha(*name) && *name != '_')
1946 		return false;
1947 	while (*++name != '\0') {
1948 		if (!isalpha(*name) && !isdigit(*name) && *name != '_')
1949 			return false;
1950 	}
1951 	return true;
1952 }
1953 
1954 #endif /* _LINUX_KERNEL_TRACE_H */
1955