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1 // SPDX-License-Identifier: GPL-2.0
2 
3 #ifndef _LINUX_KERNEL_TRACE_H
4 #define _LINUX_KERNEL_TRACE_H
5 
6 #include <linux/fs.h>
7 #include <linux/atomic.h>
8 #include <linux/sched.h>
9 #include <linux/clocksource.h>
10 #include <linux/ring_buffer.h>
11 #include <linux/mmiotrace.h>
12 #include <linux/tracepoint.h>
13 #include <linux/ftrace.h>
14 #include <linux/hw_breakpoint.h>
15 #include <linux/trace_seq.h>
16 #include <linux/trace_events.h>
17 #include <linux/compiler.h>
18 #include <linux/glob.h>
19 
20 #ifdef CONFIG_FTRACE_SYSCALLS
21 #include <asm/unistd.h>		/* For NR_SYSCALLS	     */
22 #include <asm/syscall.h>	/* some archs define it here */
23 #endif
24 
25 enum trace_type {
26 	__TRACE_FIRST_TYPE = 0,
27 
28 	TRACE_FN,
29 	TRACE_CTX,
30 	TRACE_WAKE,
31 	TRACE_STACK,
32 	TRACE_PRINT,
33 	TRACE_BPRINT,
34 	TRACE_MMIO_RW,
35 	TRACE_MMIO_MAP,
36 	TRACE_BRANCH,
37 	TRACE_GRAPH_RET,
38 	TRACE_GRAPH_ENT,
39 	TRACE_USER_STACK,
40 	TRACE_BLK,
41 	TRACE_BPUTS,
42 	TRACE_HWLAT,
43 	TRACE_RAW_DATA,
44 
45 	__TRACE_LAST_TYPE,
46 };
47 
48 
49 #undef __field
50 #define __field(type, item)		type	item;
51 
52 #undef __field_struct
53 #define __field_struct(type, item)	__field(type, item)
54 
55 #undef __field_desc
56 #define __field_desc(type, container, item)
57 
58 #undef __array
59 #define __array(type, item, size)	type	item[size];
60 
61 #undef __array_desc
62 #define __array_desc(type, container, item, size)
63 
64 #undef __dynamic_array
65 #define __dynamic_array(type, item)	type	item[];
66 
67 #undef F_STRUCT
68 #define F_STRUCT(args...)		args
69 
70 #undef FTRACE_ENTRY
71 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print, filter)	\
72 	struct struct_name {						\
73 		struct trace_entry	ent;				\
74 		tstruct							\
75 	}
76 
77 #undef FTRACE_ENTRY_DUP
78 #define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk, filter)
79 
80 #undef FTRACE_ENTRY_REG
81 #define FTRACE_ENTRY_REG(name, struct_name, id, tstruct, print,	\
82 			 filter, regfn) \
83 	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print), \
84 		     filter)
85 
86 #undef FTRACE_ENTRY_PACKED
87 #define FTRACE_ENTRY_PACKED(name, struct_name, id, tstruct, print,	\
88 			    filter)					\
89 	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print), \
90 		     filter) __packed
91 
92 #include "trace_entries.h"
93 
94 /*
95  * syscalls are special, and need special handling, this is why
96  * they are not included in trace_entries.h
97  */
98 struct syscall_trace_enter {
99 	struct trace_entry	ent;
100 	int			nr;
101 	unsigned long		args[];
102 };
103 
104 struct syscall_trace_exit {
105 	struct trace_entry	ent;
106 	int			nr;
107 	long			ret;
108 };
109 
110 struct kprobe_trace_entry_head {
111 	struct trace_entry	ent;
112 	unsigned long		ip;
113 };
114 
115 struct kretprobe_trace_entry_head {
116 	struct trace_entry	ent;
117 	unsigned long		func;
118 	unsigned long		ret_ip;
119 };
120 
121 /*
122  * trace_flag_type is an enumeration that holds different
123  * states when a trace occurs. These are:
124  *  IRQS_OFF		- interrupts were disabled
125  *  IRQS_NOSUPPORT	- arch does not support irqs_disabled_flags
126  *  NEED_RESCHED	- reschedule is requested
127  *  HARDIRQ		- inside an interrupt handler
128  *  SOFTIRQ		- inside a softirq handler
129  */
130 enum trace_flag_type {
131 	TRACE_FLAG_IRQS_OFF		= 0x01,
132 	TRACE_FLAG_IRQS_NOSUPPORT	= 0x02,
133 	TRACE_FLAG_NEED_RESCHED		= 0x04,
134 	TRACE_FLAG_HARDIRQ		= 0x08,
135 	TRACE_FLAG_SOFTIRQ		= 0x10,
136 	TRACE_FLAG_PREEMPT_RESCHED	= 0x20,
137 	TRACE_FLAG_NMI			= 0x40,
138 };
139 
140 #define TRACE_BUF_SIZE		1024
141 
142 struct trace_array;
143 
144 /*
145  * The CPU trace array - it consists of thousands of trace entries
146  * plus some other descriptor data: (for example which task started
147  * the trace, etc.)
148  */
149 struct trace_array_cpu {
150 	atomic_t		disabled;
151 	void			*buffer_page;	/* ring buffer spare */
152 
153 	unsigned long		entries;
154 	unsigned long		saved_latency;
155 	unsigned long		critical_start;
156 	unsigned long		critical_end;
157 	unsigned long		critical_sequence;
158 	unsigned long		nice;
159 	unsigned long		policy;
160 	unsigned long		rt_priority;
161 	unsigned long		skipped_entries;
162 	u64			preempt_timestamp;
163 	pid_t			pid;
164 	kuid_t			uid;
165 	char			comm[TASK_COMM_LEN];
166 
167 	bool			ignore_pid;
168 #ifdef CONFIG_FUNCTION_TRACER
169 	bool			ftrace_ignore_pid;
170 #endif
171 };
172 
173 struct tracer;
174 struct trace_option_dentry;
175 
176 struct trace_buffer {
177 	struct trace_array		*tr;
178 	struct ring_buffer		*buffer;
179 	struct trace_array_cpu __percpu	*data;
180 	u64				time_start;
181 	int				cpu;
182 };
183 
184 #define TRACE_FLAGS_MAX_SIZE		32
185 
186 struct trace_options {
187 	struct tracer			*tracer;
188 	struct trace_option_dentry	*topts;
189 };
190 
191 struct trace_pid_list {
192 	int				pid_max;
193 	unsigned long			*pids;
194 };
195 
196 typedef bool (*cond_update_fn_t)(struct trace_array *tr, void *cond_data);
197 
198 /**
199  * struct cond_snapshot - conditional snapshot data and callback
200  *
201  * The cond_snapshot structure encapsulates a callback function and
202  * data associated with the snapshot for a given tracing instance.
203  *
204  * When a snapshot is taken conditionally, by invoking
205  * tracing_snapshot_cond(tr, cond_data), the cond_data passed in is
206  * passed in turn to the cond_snapshot.update() function.  That data
207  * can be compared by the update() implementation with the cond_data
208  * contained wihin the struct cond_snapshot instance associated with
209  * the trace_array.  Because the tr->max_lock is held throughout the
210  * update() call, the update() function can directly retrieve the
211  * cond_snapshot and cond_data associated with the per-instance
212  * snapshot associated with the trace_array.
213  *
214  * The cond_snapshot.update() implementation can save data to be
215  * associated with the snapshot if it decides to, and returns 'true'
216  * in that case, or it returns 'false' if the conditional snapshot
217  * shouldn't be taken.
218  *
219  * The cond_snapshot instance is created and associated with the
220  * user-defined cond_data by tracing_cond_snapshot_enable().
221  * Likewise, the cond_snapshot instance is destroyed and is no longer
222  * associated with the trace instance by
223  * tracing_cond_snapshot_disable().
224  *
225  * The method below is required.
226  *
227  * @update: When a conditional snapshot is invoked, the update()
228  *	callback function is invoked with the tr->max_lock held.  The
229  *	update() implementation signals whether or not to actually
230  *	take the snapshot, by returning 'true' if so, 'false' if no
231  *	snapshot should be taken.  Because the max_lock is held for
232  *	the duration of update(), the implementation is safe to
233  *	directly retrieven and save any implementation data it needs
234  *	to in association with the snapshot.
235  */
236 struct cond_snapshot {
237 	void				*cond_data;
238 	cond_update_fn_t		update;
239 };
240 
241 /*
242  * The trace array - an array of per-CPU trace arrays. This is the
243  * highest level data structure that individual tracers deal with.
244  * They have on/off state as well:
245  */
246 struct trace_array {
247 	struct list_head	list;
248 	char			*name;
249 	struct trace_buffer	trace_buffer;
250 #ifdef CONFIG_TRACER_MAX_TRACE
251 	/*
252 	 * The max_buffer is used to snapshot the trace when a maximum
253 	 * latency is reached, or when the user initiates a snapshot.
254 	 * Some tracers will use this to store a maximum trace while
255 	 * it continues examining live traces.
256 	 *
257 	 * The buffers for the max_buffer are set up the same as the trace_buffer
258 	 * When a snapshot is taken, the buffer of the max_buffer is swapped
259 	 * with the buffer of the trace_buffer and the buffers are reset for
260 	 * the trace_buffer so the tracing can continue.
261 	 */
262 	struct trace_buffer	max_buffer;
263 	bool			allocated_snapshot;
264 #endif
265 #if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)
266 	unsigned long		max_latency;
267 #endif
268 	struct trace_pid_list	__rcu *filtered_pids;
269 	/*
270 	 * max_lock is used to protect the swapping of buffers
271 	 * when taking a max snapshot. The buffers themselves are
272 	 * protected by per_cpu spinlocks. But the action of the swap
273 	 * needs its own lock.
274 	 *
275 	 * This is defined as a arch_spinlock_t in order to help
276 	 * with performance when lockdep debugging is enabled.
277 	 *
278 	 * It is also used in other places outside the update_max_tr
279 	 * so it needs to be defined outside of the
280 	 * CONFIG_TRACER_MAX_TRACE.
281 	 */
282 	arch_spinlock_t		max_lock;
283 	int			buffer_disabled;
284 #ifdef CONFIG_FTRACE_SYSCALLS
285 	int			sys_refcount_enter;
286 	int			sys_refcount_exit;
287 	struct trace_event_file __rcu *enter_syscall_files[NR_syscalls];
288 	struct trace_event_file __rcu *exit_syscall_files[NR_syscalls];
289 #endif
290 	int			stop_count;
291 	int			clock_id;
292 	int			nr_topts;
293 	bool			clear_trace;
294 	int			buffer_percent;
295 	unsigned int		n_err_log_entries;
296 	struct tracer		*current_trace;
297 	unsigned int		trace_flags;
298 	unsigned char		trace_flags_index[TRACE_FLAGS_MAX_SIZE];
299 	unsigned int		flags;
300 	raw_spinlock_t		start_lock;
301 	struct list_head	err_log;
302 	struct dentry		*dir;
303 	struct dentry		*options;
304 	struct dentry		*percpu_dir;
305 	struct dentry		*event_dir;
306 	struct trace_options	*topts;
307 	struct list_head	systems;
308 	struct list_head	events;
309 	struct trace_event_file *trace_marker_file;
310 	cpumask_var_t		tracing_cpumask; /* only trace on set CPUs */
311 	int			ref;
312 #ifdef CONFIG_FUNCTION_TRACER
313 	struct ftrace_ops	*ops;
314 	struct trace_pid_list	__rcu *function_pids;
315 #ifdef CONFIG_DYNAMIC_FTRACE
316 	/* All of these are protected by the ftrace_lock */
317 	struct list_head	func_probes;
318 	struct list_head	mod_trace;
319 	struct list_head	mod_notrace;
320 #endif
321 	/* function tracing enabled */
322 	int			function_enabled;
323 #endif
324 	int			time_stamp_abs_ref;
325 	struct list_head	hist_vars;
326 #ifdef CONFIG_TRACER_SNAPSHOT
327 	struct cond_snapshot	*cond_snapshot;
328 #endif
329 };
330 
331 enum {
332 	TRACE_ARRAY_FL_GLOBAL	= (1 << 0)
333 };
334 
335 extern struct list_head ftrace_trace_arrays;
336 
337 extern struct mutex trace_types_lock;
338 
339 extern int trace_array_get(struct trace_array *tr);
340 extern void trace_array_put(struct trace_array *tr);
341 extern int tracing_check_open_get_tr(struct trace_array *tr);
342 
343 extern int tracing_set_time_stamp_abs(struct trace_array *tr, bool abs);
344 extern int tracing_set_clock(struct trace_array *tr, const char *clockstr);
345 
346 extern bool trace_clock_in_ns(struct trace_array *tr);
347 
348 /*
349  * The global tracer (top) should be the first trace array added,
350  * but we check the flag anyway.
351  */
top_trace_array(void)352 static inline struct trace_array *top_trace_array(void)
353 {
354 	struct trace_array *tr;
355 
356 	if (list_empty(&ftrace_trace_arrays))
357 		return NULL;
358 
359 	tr = list_entry(ftrace_trace_arrays.prev,
360 			typeof(*tr), list);
361 	WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
362 	return tr;
363 }
364 
365 #define FTRACE_CMP_TYPE(var, type) \
366 	__builtin_types_compatible_p(typeof(var), type *)
367 
368 #undef IF_ASSIGN
369 #define IF_ASSIGN(var, entry, etype, id)			\
370 	if (FTRACE_CMP_TYPE(var, etype)) {			\
371 		var = (typeof(var))(entry);			\
372 		WARN_ON(id != 0 && (entry)->type != id);	\
373 		break;						\
374 	}
375 
376 /* Will cause compile errors if type is not found. */
377 extern void __ftrace_bad_type(void);
378 
379 /*
380  * The trace_assign_type is a verifier that the entry type is
381  * the same as the type being assigned. To add new types simply
382  * add a line with the following format:
383  *
384  * IF_ASSIGN(var, ent, type, id);
385  *
386  *  Where "type" is the trace type that includes the trace_entry
387  *  as the "ent" item. And "id" is the trace identifier that is
388  *  used in the trace_type enum.
389  *
390  *  If the type can have more than one id, then use zero.
391  */
392 #define trace_assign_type(var, ent)					\
393 	do {								\
394 		IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);	\
395 		IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);	\
396 		IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);	\
397 		IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
398 		IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);	\
399 		IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT);	\
400 		IF_ASSIGN(var, ent, struct bputs_entry, TRACE_BPUTS);	\
401 		IF_ASSIGN(var, ent, struct hwlat_entry, TRACE_HWLAT);	\
402 		IF_ASSIGN(var, ent, struct raw_data_entry, TRACE_RAW_DATA);\
403 		IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,		\
404 			  TRACE_MMIO_RW);				\
405 		IF_ASSIGN(var, ent, struct trace_mmiotrace_map,		\
406 			  TRACE_MMIO_MAP);				\
407 		IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
408 		IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,	\
409 			  TRACE_GRAPH_ENT);		\
410 		IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,	\
411 			  TRACE_GRAPH_RET);		\
412 		__ftrace_bad_type();					\
413 	} while (0)
414 
415 /*
416  * An option specific to a tracer. This is a boolean value.
417  * The bit is the bit index that sets its value on the
418  * flags value in struct tracer_flags.
419  */
420 struct tracer_opt {
421 	const char	*name; /* Will appear on the trace_options file */
422 	u32		bit; /* Mask assigned in val field in tracer_flags */
423 };
424 
425 /*
426  * The set of specific options for a tracer. Your tracer
427  * have to set the initial value of the flags val.
428  */
429 struct tracer_flags {
430 	u32			val;
431 	struct tracer_opt	*opts;
432 	struct tracer		*trace;
433 };
434 
435 /* Makes more easy to define a tracer opt */
436 #define TRACER_OPT(s, b)	.name = #s, .bit = b
437 
438 
439 struct trace_option_dentry {
440 	struct tracer_opt		*opt;
441 	struct tracer_flags		*flags;
442 	struct trace_array		*tr;
443 	struct dentry			*entry;
444 };
445 
446 /**
447  * struct tracer - a specific tracer and its callbacks to interact with tracefs
448  * @name: the name chosen to select it on the available_tracers file
449  * @init: called when one switches to this tracer (echo name > current_tracer)
450  * @reset: called when one switches to another tracer
451  * @start: called when tracing is unpaused (echo 1 > tracing_on)
452  * @stop: called when tracing is paused (echo 0 > tracing_on)
453  * @update_thresh: called when tracing_thresh is updated
454  * @open: called when the trace file is opened
455  * @pipe_open: called when the trace_pipe file is opened
456  * @close: called when the trace file is released
457  * @pipe_close: called when the trace_pipe file is released
458  * @read: override the default read callback on trace_pipe
459  * @splice_read: override the default splice_read callback on trace_pipe
460  * @selftest: selftest to run on boot (see trace_selftest.c)
461  * @print_headers: override the first lines that describe your columns
462  * @print_line: callback that prints a trace
463  * @set_flag: signals one of your private flags changed (trace_options file)
464  * @flags: your private flags
465  */
466 struct tracer {
467 	const char		*name;
468 	int			(*init)(struct trace_array *tr);
469 	void			(*reset)(struct trace_array *tr);
470 	void			(*start)(struct trace_array *tr);
471 	void			(*stop)(struct trace_array *tr);
472 	int			(*update_thresh)(struct trace_array *tr);
473 	void			(*open)(struct trace_iterator *iter);
474 	void			(*pipe_open)(struct trace_iterator *iter);
475 	void			(*close)(struct trace_iterator *iter);
476 	void			(*pipe_close)(struct trace_iterator *iter);
477 	ssize_t			(*read)(struct trace_iterator *iter,
478 					struct file *filp, char __user *ubuf,
479 					size_t cnt, loff_t *ppos);
480 	ssize_t			(*splice_read)(struct trace_iterator *iter,
481 					       struct file *filp,
482 					       loff_t *ppos,
483 					       struct pipe_inode_info *pipe,
484 					       size_t len,
485 					       unsigned int flags);
486 #ifdef CONFIG_FTRACE_STARTUP_TEST
487 	int			(*selftest)(struct tracer *trace,
488 					    struct trace_array *tr);
489 #endif
490 	void			(*print_header)(struct seq_file *m);
491 	enum print_line_t	(*print_line)(struct trace_iterator *iter);
492 	/* If you handled the flag setting, return 0 */
493 	int			(*set_flag)(struct trace_array *tr,
494 					    u32 old_flags, u32 bit, int set);
495 	/* Return 0 if OK with change, else return non-zero */
496 	int			(*flag_changed)(struct trace_array *tr,
497 						u32 mask, int set);
498 	struct tracer		*next;
499 	struct tracer_flags	*flags;
500 	int			enabled;
501 	int			ref;
502 	bool			print_max;
503 	bool			allow_instances;
504 #ifdef CONFIG_TRACER_MAX_TRACE
505 	bool			use_max_tr;
506 #endif
507 	/* True if tracer cannot be enabled in kernel param */
508 	bool			noboot;
509 };
510 
511 
512 /* Only current can touch trace_recursion */
513 
514 /*
515  * For function tracing recursion:
516  *  The order of these bits are important.
517  *
518  *  When function tracing occurs, the following steps are made:
519  *   If arch does not support a ftrace feature:
520  *    call internal function (uses INTERNAL bits) which calls...
521  *   The function callback, which can use the FTRACE bits to
522  *    check for recursion.
523  */
524 enum {
525 	TRACE_BUFFER_BIT,
526 	TRACE_BUFFER_NMI_BIT,
527 	TRACE_BUFFER_IRQ_BIT,
528 	TRACE_BUFFER_SIRQ_BIT,
529 
530 	/* Start of function recursion bits */
531 	TRACE_FTRACE_BIT,
532 	TRACE_FTRACE_NMI_BIT,
533 	TRACE_FTRACE_IRQ_BIT,
534 	TRACE_FTRACE_SIRQ_BIT,
535 	TRACE_FTRACE_TRANSITION_BIT,
536 
537 	/* Internal use recursion bits */
538 	TRACE_INTERNAL_BIT,
539 	TRACE_INTERNAL_NMI_BIT,
540 	TRACE_INTERNAL_IRQ_BIT,
541 	TRACE_INTERNAL_SIRQ_BIT,
542 	TRACE_INTERNAL_TRANSITION_BIT,
543 
544 	TRACE_BRANCH_BIT,
545 /*
546  * Abuse of the trace_recursion.
547  * As we need a way to maintain state if we are tracing the function
548  * graph in irq because we want to trace a particular function that
549  * was called in irq context but we have irq tracing off. Since this
550  * can only be modified by current, we can reuse trace_recursion.
551  */
552 	TRACE_IRQ_BIT,
553 
554 	/* Set if the function is in the set_graph_function file */
555 	TRACE_GRAPH_BIT,
556 
557 	/*
558 	 * In the very unlikely case that an interrupt came in
559 	 * at a start of graph tracing, and we want to trace
560 	 * the function in that interrupt, the depth can be greater
561 	 * than zero, because of the preempted start of a previous
562 	 * trace. In an even more unlikely case, depth could be 2
563 	 * if a softirq interrupted the start of graph tracing,
564 	 * followed by an interrupt preempting a start of graph
565 	 * tracing in the softirq, and depth can even be 3
566 	 * if an NMI came in at the start of an interrupt function
567 	 * that preempted a softirq start of a function that
568 	 * preempted normal context!!!! Luckily, it can't be
569 	 * greater than 3, so the next two bits are a mask
570 	 * of what the depth is when we set TRACE_GRAPH_BIT
571 	 */
572 
573 	TRACE_GRAPH_DEPTH_START_BIT,
574 	TRACE_GRAPH_DEPTH_END_BIT,
575 
576 	/*
577 	 * To implement set_graph_notrace, if this bit is set, we ignore
578 	 * function graph tracing of called functions, until the return
579 	 * function is called to clear it.
580 	 */
581 	TRACE_GRAPH_NOTRACE_BIT,
582 };
583 
584 #define trace_recursion_set(bit)	do { (current)->trace_recursion |= (1<<(bit)); } while (0)
585 #define trace_recursion_clear(bit)	do { (current)->trace_recursion &= ~(1<<(bit)); } while (0)
586 #define trace_recursion_test(bit)	((current)->trace_recursion & (1<<(bit)))
587 
588 #define trace_recursion_depth() \
589 	(((current)->trace_recursion >> TRACE_GRAPH_DEPTH_START_BIT) & 3)
590 #define trace_recursion_set_depth(depth) \
591 	do {								\
592 		current->trace_recursion &=				\
593 			~(3 << TRACE_GRAPH_DEPTH_START_BIT);		\
594 		current->trace_recursion |=				\
595 			((depth) & 3) << TRACE_GRAPH_DEPTH_START_BIT;	\
596 	} while (0)
597 
598 #define TRACE_CONTEXT_BITS	4
599 
600 #define TRACE_FTRACE_START	TRACE_FTRACE_BIT
601 
602 #define TRACE_LIST_START	TRACE_INTERNAL_BIT
603 
604 #define TRACE_CONTEXT_MASK	((1 << (TRACE_LIST_START + TRACE_CONTEXT_BITS)) - 1)
605 
606 enum {
607 	TRACE_CTX_NMI,
608 	TRACE_CTX_IRQ,
609 	TRACE_CTX_SOFTIRQ,
610 	TRACE_CTX_NORMAL,
611 	TRACE_CTX_TRANSITION,
612 };
613 
trace_get_context_bit(void)614 static __always_inline int trace_get_context_bit(void)
615 {
616 	int bit;
617 
618 	if (in_interrupt()) {
619 		if (in_nmi())
620 			bit = TRACE_CTX_NMI;
621 
622 		else if (in_irq())
623 			bit = TRACE_CTX_IRQ;
624 		else
625 			bit = TRACE_CTX_SOFTIRQ;
626 	} else
627 		bit = TRACE_CTX_NORMAL;
628 
629 	return bit;
630 }
631 
trace_test_and_set_recursion(int start)632 static __always_inline int trace_test_and_set_recursion(int start)
633 {
634 	unsigned int val = current->trace_recursion;
635 	int bit;
636 
637 	bit = trace_get_context_bit() + start;
638 	if (unlikely(val & (1 << bit))) {
639 		/*
640 		 * It could be that preempt_count has not been updated during
641 		 * a switch between contexts. Allow for a single recursion.
642 		 */
643 		bit = start + TRACE_CTX_TRANSITION;
644 		if (trace_recursion_test(bit))
645 			return -1;
646 		trace_recursion_set(bit);
647 		barrier();
648 		return bit;
649 	}
650 
651 	val |= 1 << bit;
652 	current->trace_recursion = val;
653 	barrier();
654 
655 	return bit;
656 }
657 
trace_clear_recursion(int bit)658 static __always_inline void trace_clear_recursion(int bit)
659 {
660 	unsigned int val = current->trace_recursion;
661 
662 	bit = 1 << bit;
663 	val &= ~bit;
664 
665 	barrier();
666 	current->trace_recursion = val;
667 }
668 
669 static inline struct ring_buffer_iter *
trace_buffer_iter(struct trace_iterator * iter,int cpu)670 trace_buffer_iter(struct trace_iterator *iter, int cpu)
671 {
672 	return iter->buffer_iter ? iter->buffer_iter[cpu] : NULL;
673 }
674 
675 int tracer_init(struct tracer *t, struct trace_array *tr);
676 int tracing_is_enabled(void);
677 void tracing_reset_online_cpus(struct trace_buffer *buf);
678 void tracing_reset_current(int cpu);
679 void tracing_reset_all_online_cpus(void);
680 void tracing_reset_all_online_cpus_unlocked(void);
681 int tracing_open_generic(struct inode *inode, struct file *filp);
682 int tracing_open_generic_tr(struct inode *inode, struct file *filp);
683 int tracing_open_file_tr(struct inode *inode, struct file *filp);
684 int tracing_release_file_tr(struct inode *inode, struct file *filp);
685 bool tracing_is_disabled(void);
686 bool tracer_tracing_is_on(struct trace_array *tr);
687 void tracer_tracing_on(struct trace_array *tr);
688 void tracer_tracing_off(struct trace_array *tr);
689 struct dentry *trace_create_file(const char *name,
690 				 umode_t mode,
691 				 struct dentry *parent,
692 				 void *data,
693 				 const struct file_operations *fops);
694 
695 struct dentry *tracing_init_dentry(void);
696 
697 struct ring_buffer_event;
698 
699 struct ring_buffer_event *
700 trace_buffer_lock_reserve(struct ring_buffer *buffer,
701 			  int type,
702 			  unsigned long len,
703 			  unsigned long flags,
704 			  int pc);
705 
706 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
707 						struct trace_array_cpu *data);
708 
709 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
710 					  int *ent_cpu, u64 *ent_ts);
711 
712 void trace_buffer_unlock_commit_nostack(struct ring_buffer *buffer,
713 					struct ring_buffer_event *event);
714 
715 int trace_empty(struct trace_iterator *iter);
716 
717 void *trace_find_next_entry_inc(struct trace_iterator *iter);
718 
719 void trace_init_global_iter(struct trace_iterator *iter);
720 
721 void tracing_iter_reset(struct trace_iterator *iter, int cpu);
722 
723 unsigned long trace_total_entries_cpu(struct trace_array *tr, int cpu);
724 unsigned long trace_total_entries(struct trace_array *tr);
725 
726 void trace_function(struct trace_array *tr,
727 		    unsigned long ip,
728 		    unsigned long parent_ip,
729 		    unsigned long flags, int pc);
730 void trace_graph_function(struct trace_array *tr,
731 		    unsigned long ip,
732 		    unsigned long parent_ip,
733 		    unsigned long flags, int pc);
734 void trace_latency_header(struct seq_file *m);
735 void trace_default_header(struct seq_file *m);
736 void print_trace_header(struct seq_file *m, struct trace_iterator *iter);
737 int trace_empty(struct trace_iterator *iter);
738 
739 void trace_graph_return(struct ftrace_graph_ret *trace);
740 int trace_graph_entry(struct ftrace_graph_ent *trace);
741 void set_graph_array(struct trace_array *tr);
742 
743 void tracing_start_cmdline_record(void);
744 void tracing_stop_cmdline_record(void);
745 void tracing_start_tgid_record(void);
746 void tracing_stop_tgid_record(void);
747 
748 int register_tracer(struct tracer *type);
749 int is_tracing_stopped(void);
750 
751 loff_t tracing_lseek(struct file *file, loff_t offset, int whence);
752 
753 extern cpumask_var_t __read_mostly tracing_buffer_mask;
754 
755 #define for_each_tracing_cpu(cpu)	\
756 	for_each_cpu(cpu, tracing_buffer_mask)
757 
758 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
759 
760 extern unsigned long tracing_thresh;
761 
762 /* PID filtering */
763 
764 extern int pid_max;
765 
766 bool trace_find_filtered_pid(struct trace_pid_list *filtered_pids,
767 			     pid_t search_pid);
768 bool trace_ignore_this_task(struct trace_pid_list *filtered_pids,
769 			    struct task_struct *task);
770 void trace_filter_add_remove_task(struct trace_pid_list *pid_list,
771 				  struct task_struct *self,
772 				  struct task_struct *task);
773 void *trace_pid_next(struct trace_pid_list *pid_list, void *v, loff_t *pos);
774 void *trace_pid_start(struct trace_pid_list *pid_list, loff_t *pos);
775 int trace_pid_show(struct seq_file *m, void *v);
776 void trace_free_pid_list(struct trace_pid_list *pid_list);
777 int trace_pid_write(struct trace_pid_list *filtered_pids,
778 		    struct trace_pid_list **new_pid_list,
779 		    const char __user *ubuf, size_t cnt);
780 
781 #ifdef CONFIG_TRACER_MAX_TRACE
782 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu,
783 		   void *cond_data);
784 void update_max_tr_single(struct trace_array *tr,
785 			  struct task_struct *tsk, int cpu);
786 #endif /* CONFIG_TRACER_MAX_TRACE */
787 
788 #ifdef CONFIG_STACKTRACE
789 void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
790 		   int pc);
791 #else
__trace_stack(struct trace_array * tr,unsigned long flags,int skip,int pc)792 static inline void __trace_stack(struct trace_array *tr, unsigned long flags,
793 				 int skip, int pc)
794 {
795 }
796 #endif /* CONFIG_STACKTRACE */
797 
798 extern u64 ftrace_now(int cpu);
799 
800 extern void trace_find_cmdline(int pid, char comm[]);
801 extern int trace_find_tgid(int pid);
802 extern void trace_event_follow_fork(struct trace_array *tr, bool enable);
803 
804 #ifdef CONFIG_DYNAMIC_FTRACE
805 extern unsigned long ftrace_update_tot_cnt;
806 extern unsigned long ftrace_number_of_pages;
807 extern unsigned long ftrace_number_of_groups;
808 void ftrace_init_trace_array(struct trace_array *tr);
809 #else
ftrace_init_trace_array(struct trace_array * tr)810 static inline void ftrace_init_trace_array(struct trace_array *tr) { }
811 #endif
812 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
813 extern int DYN_FTRACE_TEST_NAME(void);
814 #define DYN_FTRACE_TEST_NAME2 trace_selftest_dynamic_test_func2
815 extern int DYN_FTRACE_TEST_NAME2(void);
816 
817 extern bool ring_buffer_expanded;
818 extern bool tracing_selftest_disabled;
819 
820 #ifdef CONFIG_FTRACE_STARTUP_TEST
821 extern int trace_selftest_startup_function(struct tracer *trace,
822 					   struct trace_array *tr);
823 extern int trace_selftest_startup_function_graph(struct tracer *trace,
824 						 struct trace_array *tr);
825 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
826 					  struct trace_array *tr);
827 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
828 					     struct trace_array *tr);
829 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
830 						 struct trace_array *tr);
831 extern int trace_selftest_startup_wakeup(struct tracer *trace,
832 					 struct trace_array *tr);
833 extern int trace_selftest_startup_nop(struct tracer *trace,
834 					 struct trace_array *tr);
835 extern int trace_selftest_startup_branch(struct tracer *trace,
836 					 struct trace_array *tr);
837 /*
838  * Tracer data references selftest functions that only occur
839  * on boot up. These can be __init functions. Thus, when selftests
840  * are enabled, then the tracers need to reference __init functions.
841  */
842 #define __tracer_data		__refdata
843 #else
844 /* Tracers are seldom changed. Optimize when selftests are disabled. */
845 #define __tracer_data		__read_mostly
846 #endif /* CONFIG_FTRACE_STARTUP_TEST */
847 
848 extern void *head_page(struct trace_array_cpu *data);
849 extern unsigned long long ns2usecs(u64 nsec);
850 extern int
851 trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
852 extern int
853 trace_vprintk(unsigned long ip, const char *fmt, va_list args);
854 extern int
855 trace_array_vprintk(struct trace_array *tr,
856 		    unsigned long ip, const char *fmt, va_list args);
857 int trace_array_printk(struct trace_array *tr,
858 		       unsigned long ip, const char *fmt, ...);
859 int trace_array_printk_buf(struct ring_buffer *buffer,
860 			   unsigned long ip, const char *fmt, ...);
861 void trace_printk_seq(struct trace_seq *s);
862 enum print_line_t print_trace_line(struct trace_iterator *iter);
863 
864 extern char trace_find_mark(unsigned long long duration);
865 
866 struct ftrace_hash;
867 
868 struct ftrace_mod_load {
869 	struct list_head	list;
870 	char			*func;
871 	char			*module;
872 	int			 enable;
873 };
874 
875 enum {
876 	FTRACE_HASH_FL_MOD	= (1 << 0),
877 };
878 
879 struct ftrace_hash {
880 	unsigned long		size_bits;
881 	struct hlist_head	*buckets;
882 	unsigned long		count;
883 	unsigned long		flags;
884 	struct rcu_head		rcu;
885 };
886 
887 struct ftrace_func_entry *
888 ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip);
889 
ftrace_hash_empty(struct ftrace_hash * hash)890 static __always_inline bool ftrace_hash_empty(struct ftrace_hash *hash)
891 {
892 	return !hash || !(hash->count || (hash->flags & FTRACE_HASH_FL_MOD));
893 }
894 
895 /* Standard output formatting function used for function return traces */
896 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
897 
898 /* Flag options */
899 #define TRACE_GRAPH_PRINT_OVERRUN       0x1
900 #define TRACE_GRAPH_PRINT_CPU           0x2
901 #define TRACE_GRAPH_PRINT_OVERHEAD      0x4
902 #define TRACE_GRAPH_PRINT_PROC          0x8
903 #define TRACE_GRAPH_PRINT_DURATION      0x10
904 #define TRACE_GRAPH_PRINT_ABS_TIME      0x20
905 #define TRACE_GRAPH_PRINT_REL_TIME      0x40
906 #define TRACE_GRAPH_PRINT_IRQS          0x80
907 #define TRACE_GRAPH_PRINT_TAIL          0x100
908 #define TRACE_GRAPH_SLEEP_TIME          0x200
909 #define TRACE_GRAPH_GRAPH_TIME          0x400
910 #define TRACE_GRAPH_PRINT_FILL_SHIFT	28
911 #define TRACE_GRAPH_PRINT_FILL_MASK	(0x3 << TRACE_GRAPH_PRINT_FILL_SHIFT)
912 
913 extern void ftrace_graph_sleep_time_control(bool enable);
914 
915 #ifdef CONFIG_FUNCTION_PROFILER
916 extern void ftrace_graph_graph_time_control(bool enable);
917 #else
ftrace_graph_graph_time_control(bool enable)918 static inline void ftrace_graph_graph_time_control(bool enable) { }
919 #endif
920 
921 extern enum print_line_t
922 print_graph_function_flags(struct trace_iterator *iter, u32 flags);
923 extern void print_graph_headers_flags(struct seq_file *s, u32 flags);
924 extern void
925 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
926 extern void graph_trace_open(struct trace_iterator *iter);
927 extern void graph_trace_close(struct trace_iterator *iter);
928 extern int __trace_graph_entry(struct trace_array *tr,
929 			       struct ftrace_graph_ent *trace,
930 			       unsigned long flags, int pc);
931 extern void __trace_graph_return(struct trace_array *tr,
932 				 struct ftrace_graph_ret *trace,
933 				 unsigned long flags, int pc);
934 
935 #ifdef CONFIG_DYNAMIC_FTRACE
936 extern struct ftrace_hash __rcu *ftrace_graph_hash;
937 extern struct ftrace_hash __rcu *ftrace_graph_notrace_hash;
938 
ftrace_graph_addr(struct ftrace_graph_ent * trace)939 static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace)
940 {
941 	unsigned long addr = trace->func;
942 	int ret = 0;
943 	struct ftrace_hash *hash;
944 
945 	preempt_disable_notrace();
946 
947 	/*
948 	 * Have to open code "rcu_dereference_sched()" because the
949 	 * function graph tracer can be called when RCU is not
950 	 * "watching".
951 	 * Protected with schedule_on_each_cpu(ftrace_sync)
952 	 */
953 	hash = rcu_dereference_protected(ftrace_graph_hash, !preemptible());
954 
955 	if (ftrace_hash_empty(hash)) {
956 		ret = 1;
957 		goto out;
958 	}
959 
960 	if (ftrace_lookup_ip(hash, addr)) {
961 
962 		/*
963 		 * This needs to be cleared on the return functions
964 		 * when the depth is zero.
965 		 */
966 		trace_recursion_set(TRACE_GRAPH_BIT);
967 		trace_recursion_set_depth(trace->depth);
968 
969 		/*
970 		 * If no irqs are to be traced, but a set_graph_function
971 		 * is set, and called by an interrupt handler, we still
972 		 * want to trace it.
973 		 */
974 		if (in_irq())
975 			trace_recursion_set(TRACE_IRQ_BIT);
976 		else
977 			trace_recursion_clear(TRACE_IRQ_BIT);
978 		ret = 1;
979 	}
980 
981 out:
982 	preempt_enable_notrace();
983 	return ret;
984 }
985 
ftrace_graph_addr_finish(struct ftrace_graph_ret * trace)986 static inline void ftrace_graph_addr_finish(struct ftrace_graph_ret *trace)
987 {
988 	if (trace_recursion_test(TRACE_GRAPH_BIT) &&
989 	    trace->depth == trace_recursion_depth())
990 		trace_recursion_clear(TRACE_GRAPH_BIT);
991 }
992 
ftrace_graph_notrace_addr(unsigned long addr)993 static inline int ftrace_graph_notrace_addr(unsigned long addr)
994 {
995 	int ret = 0;
996 	struct ftrace_hash *notrace_hash;
997 
998 	preempt_disable_notrace();
999 
1000 	/*
1001 	 * Have to open code "rcu_dereference_sched()" because the
1002 	 * function graph tracer can be called when RCU is not
1003 	 * "watching".
1004 	 * Protected with schedule_on_each_cpu(ftrace_sync)
1005 	 */
1006 	notrace_hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
1007 						 !preemptible());
1008 
1009 	if (ftrace_lookup_ip(notrace_hash, addr))
1010 		ret = 1;
1011 
1012 	preempt_enable_notrace();
1013 	return ret;
1014 }
1015 #else
ftrace_graph_addr(struct ftrace_graph_ent * trace)1016 static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace)
1017 {
1018 	return 1;
1019 }
1020 
ftrace_graph_notrace_addr(unsigned long addr)1021 static inline int ftrace_graph_notrace_addr(unsigned long addr)
1022 {
1023 	return 0;
1024 }
ftrace_graph_addr_finish(struct ftrace_graph_ret * trace)1025 static inline void ftrace_graph_addr_finish(struct ftrace_graph_ret *trace)
1026 { }
1027 #endif /* CONFIG_DYNAMIC_FTRACE */
1028 
1029 extern unsigned int fgraph_max_depth;
1030 
ftrace_graph_ignore_func(struct ftrace_graph_ent * trace)1031 static inline bool ftrace_graph_ignore_func(struct ftrace_graph_ent *trace)
1032 {
1033 	/* trace it when it is-nested-in or is a function enabled. */
1034 	return !(trace_recursion_test(TRACE_GRAPH_BIT) ||
1035 		 ftrace_graph_addr(trace)) ||
1036 		(trace->depth < 0) ||
1037 		(fgraph_max_depth && trace->depth >= fgraph_max_depth);
1038 }
1039 
1040 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
1041 static inline enum print_line_t
print_graph_function_flags(struct trace_iterator * iter,u32 flags)1042 print_graph_function_flags(struct trace_iterator *iter, u32 flags)
1043 {
1044 	return TRACE_TYPE_UNHANDLED;
1045 }
1046 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
1047 
1048 extern struct list_head ftrace_pids;
1049 
1050 #ifdef CONFIG_FUNCTION_TRACER
1051 struct ftrace_func_command {
1052 	struct list_head	list;
1053 	char			*name;
1054 	int			(*func)(struct trace_array *tr,
1055 					struct ftrace_hash *hash,
1056 					char *func, char *cmd,
1057 					char *params, int enable);
1058 };
1059 extern bool ftrace_filter_param __initdata;
ftrace_trace_task(struct trace_array * tr)1060 static inline int ftrace_trace_task(struct trace_array *tr)
1061 {
1062 	return !this_cpu_read(tr->trace_buffer.data->ftrace_ignore_pid);
1063 }
1064 extern int ftrace_is_dead(void);
1065 int ftrace_create_function_files(struct trace_array *tr,
1066 				 struct dentry *parent);
1067 void ftrace_destroy_function_files(struct trace_array *tr);
1068 void ftrace_init_global_array_ops(struct trace_array *tr);
1069 void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func);
1070 void ftrace_reset_array_ops(struct trace_array *tr);
1071 void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer);
1072 void ftrace_init_tracefs_toplevel(struct trace_array *tr,
1073 				  struct dentry *d_tracer);
1074 void ftrace_clear_pids(struct trace_array *tr);
1075 int init_function_trace(void);
1076 void ftrace_pid_follow_fork(struct trace_array *tr, bool enable);
1077 #else
ftrace_trace_task(struct trace_array * tr)1078 static inline int ftrace_trace_task(struct trace_array *tr)
1079 {
1080 	return 1;
1081 }
ftrace_is_dead(void)1082 static inline int ftrace_is_dead(void) { return 0; }
1083 static inline int
ftrace_create_function_files(struct trace_array * tr,struct dentry * parent)1084 ftrace_create_function_files(struct trace_array *tr,
1085 			     struct dentry *parent)
1086 {
1087 	return 0;
1088 }
ftrace_destroy_function_files(struct trace_array * tr)1089 static inline void ftrace_destroy_function_files(struct trace_array *tr) { }
1090 static inline __init void
ftrace_init_global_array_ops(struct trace_array * tr)1091 ftrace_init_global_array_ops(struct trace_array *tr) { }
ftrace_reset_array_ops(struct trace_array * tr)1092 static inline void ftrace_reset_array_ops(struct trace_array *tr) { }
ftrace_init_tracefs(struct trace_array * tr,struct dentry * d)1093 static inline void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d) { }
ftrace_init_tracefs_toplevel(struct trace_array * tr,struct dentry * d)1094 static inline void ftrace_init_tracefs_toplevel(struct trace_array *tr, struct dentry *d) { }
ftrace_clear_pids(struct trace_array * tr)1095 static inline void ftrace_clear_pids(struct trace_array *tr) { }
init_function_trace(void)1096 static inline int init_function_trace(void) { return 0; }
ftrace_pid_follow_fork(struct trace_array * tr,bool enable)1097 static inline void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) { }
1098 /* ftace_func_t type is not defined, use macro instead of static inline */
1099 #define ftrace_init_array_ops(tr, func) do { } while (0)
1100 #endif /* CONFIG_FUNCTION_TRACER */
1101 
1102 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
1103 
1104 struct ftrace_probe_ops {
1105 	void			(*func)(unsigned long ip,
1106 					unsigned long parent_ip,
1107 					struct trace_array *tr,
1108 					struct ftrace_probe_ops *ops,
1109 					void *data);
1110 	int			(*init)(struct ftrace_probe_ops *ops,
1111 					struct trace_array *tr,
1112 					unsigned long ip, void *init_data,
1113 					void **data);
1114 	void			(*free)(struct ftrace_probe_ops *ops,
1115 					struct trace_array *tr,
1116 					unsigned long ip, void *data);
1117 	int			(*print)(struct seq_file *m,
1118 					 unsigned long ip,
1119 					 struct ftrace_probe_ops *ops,
1120 					 void *data);
1121 };
1122 
1123 struct ftrace_func_mapper;
1124 typedef int (*ftrace_mapper_func)(void *data);
1125 
1126 struct ftrace_func_mapper *allocate_ftrace_func_mapper(void);
1127 void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
1128 					   unsigned long ip);
1129 int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
1130 			       unsigned long ip, void *data);
1131 void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
1132 				   unsigned long ip);
1133 void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
1134 			     ftrace_mapper_func free_func);
1135 
1136 extern int
1137 register_ftrace_function_probe(char *glob, struct trace_array *tr,
1138 			       struct ftrace_probe_ops *ops, void *data);
1139 extern int
1140 unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
1141 				      struct ftrace_probe_ops *ops);
1142 extern void clear_ftrace_function_probes(struct trace_array *tr);
1143 
1144 int register_ftrace_command(struct ftrace_func_command *cmd);
1145 int unregister_ftrace_command(struct ftrace_func_command *cmd);
1146 
1147 void ftrace_create_filter_files(struct ftrace_ops *ops,
1148 				struct dentry *parent);
1149 void ftrace_destroy_filter_files(struct ftrace_ops *ops);
1150 #else
1151 struct ftrace_func_command;
1152 
register_ftrace_command(struct ftrace_func_command * cmd)1153 static inline __init int register_ftrace_command(struct ftrace_func_command *cmd)
1154 {
1155 	return -EINVAL;
1156 }
unregister_ftrace_command(char * cmd_name)1157 static inline __init int unregister_ftrace_command(char *cmd_name)
1158 {
1159 	return -EINVAL;
1160 }
clear_ftrace_function_probes(struct trace_array * tr)1161 static inline void clear_ftrace_function_probes(struct trace_array *tr)
1162 {
1163 }
1164 
1165 /*
1166  * The ops parameter passed in is usually undefined.
1167  * This must be a macro.
1168  */
1169 #define ftrace_create_filter_files(ops, parent) do { } while (0)
1170 #define ftrace_destroy_filter_files(ops) do { } while (0)
1171 #endif /* CONFIG_FUNCTION_TRACER && CONFIG_DYNAMIC_FTRACE */
1172 
1173 bool ftrace_event_is_function(struct trace_event_call *call);
1174 
1175 /*
1176  * struct trace_parser - servers for reading the user input separated by spaces
1177  * @cont: set if the input is not complete - no final space char was found
1178  * @buffer: holds the parsed user input
1179  * @idx: user input length
1180  * @size: buffer size
1181  */
1182 struct trace_parser {
1183 	bool		cont;
1184 	char		*buffer;
1185 	unsigned	idx;
1186 	unsigned	size;
1187 };
1188 
trace_parser_loaded(struct trace_parser * parser)1189 static inline bool trace_parser_loaded(struct trace_parser *parser)
1190 {
1191 	return (parser->idx != 0);
1192 }
1193 
trace_parser_cont(struct trace_parser * parser)1194 static inline bool trace_parser_cont(struct trace_parser *parser)
1195 {
1196 	return parser->cont;
1197 }
1198 
trace_parser_clear(struct trace_parser * parser)1199 static inline void trace_parser_clear(struct trace_parser *parser)
1200 {
1201 	parser->cont = false;
1202 	parser->idx = 0;
1203 }
1204 
1205 extern int trace_parser_get_init(struct trace_parser *parser, int size);
1206 extern void trace_parser_put(struct trace_parser *parser);
1207 extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
1208 	size_t cnt, loff_t *ppos);
1209 
1210 /*
1211  * Only create function graph options if function graph is configured.
1212  */
1213 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1214 # define FGRAPH_FLAGS						\
1215 		C(DISPLAY_GRAPH,	"display-graph"),
1216 #else
1217 # define FGRAPH_FLAGS
1218 #endif
1219 
1220 #ifdef CONFIG_BRANCH_TRACER
1221 # define BRANCH_FLAGS					\
1222 		C(BRANCH,		"branch"),
1223 #else
1224 # define BRANCH_FLAGS
1225 #endif
1226 
1227 #ifdef CONFIG_FUNCTION_TRACER
1228 # define FUNCTION_FLAGS						\
1229 		C(FUNCTION,		"function-trace"),	\
1230 		C(FUNC_FORK,		"function-fork"),
1231 # define FUNCTION_DEFAULT_FLAGS		TRACE_ITER_FUNCTION
1232 #else
1233 # define FUNCTION_FLAGS
1234 # define FUNCTION_DEFAULT_FLAGS		0UL
1235 # define TRACE_ITER_FUNC_FORK		0UL
1236 #endif
1237 
1238 #ifdef CONFIG_STACKTRACE
1239 # define STACK_FLAGS				\
1240 		C(STACKTRACE,		"stacktrace"),
1241 #else
1242 # define STACK_FLAGS
1243 #endif
1244 
1245 /*
1246  * trace_iterator_flags is an enumeration that defines bit
1247  * positions into trace_flags that controls the output.
1248  *
1249  * NOTE: These bits must match the trace_options array in
1250  *       trace.c (this macro guarantees it).
1251  */
1252 #define TRACE_FLAGS						\
1253 		C(PRINT_PARENT,		"print-parent"),	\
1254 		C(SYM_OFFSET,		"sym-offset"),		\
1255 		C(SYM_ADDR,		"sym-addr"),		\
1256 		C(VERBOSE,		"verbose"),		\
1257 		C(RAW,			"raw"),			\
1258 		C(HEX,			"hex"),			\
1259 		C(BIN,			"bin"),			\
1260 		C(BLOCK,		"block"),		\
1261 		C(PRINTK,		"trace_printk"),	\
1262 		C(ANNOTATE,		"annotate"),		\
1263 		C(USERSTACKTRACE,	"userstacktrace"),	\
1264 		C(SYM_USEROBJ,		"sym-userobj"),		\
1265 		C(PRINTK_MSGONLY,	"printk-msg-only"),	\
1266 		C(CONTEXT_INFO,		"context-info"),   /* Print pid/cpu/time */ \
1267 		C(LATENCY_FMT,		"latency-format"),	\
1268 		C(RECORD_CMD,		"record-cmd"),		\
1269 		C(RECORD_TGID,		"record-tgid"),		\
1270 		C(OVERWRITE,		"overwrite"),		\
1271 		C(STOP_ON_FREE,		"disable_on_free"),	\
1272 		C(IRQ_INFO,		"irq-info"),		\
1273 		C(MARKERS,		"markers"),		\
1274 		C(EVENT_FORK,		"event-fork"),		\
1275 		FUNCTION_FLAGS					\
1276 		FGRAPH_FLAGS					\
1277 		STACK_FLAGS					\
1278 		BRANCH_FLAGS
1279 
1280 /*
1281  * By defining C, we can make TRACE_FLAGS a list of bit names
1282  * that will define the bits for the flag masks.
1283  */
1284 #undef C
1285 #define C(a, b) TRACE_ITER_##a##_BIT
1286 
1287 enum trace_iterator_bits {
1288 	TRACE_FLAGS
1289 	/* Make sure we don't go more than we have bits for */
1290 	TRACE_ITER_LAST_BIT
1291 };
1292 
1293 /*
1294  * By redefining C, we can make TRACE_FLAGS a list of masks that
1295  * use the bits as defined above.
1296  */
1297 #undef C
1298 #define C(a, b) TRACE_ITER_##a = (1 << TRACE_ITER_##a##_BIT)
1299 
1300 enum trace_iterator_flags { TRACE_FLAGS };
1301 
1302 /*
1303  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
1304  * control the output of kernel symbols.
1305  */
1306 #define TRACE_ITER_SYM_MASK \
1307 	(TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
1308 
1309 extern struct tracer nop_trace;
1310 
1311 #ifdef CONFIG_BRANCH_TRACER
1312 extern int enable_branch_tracing(struct trace_array *tr);
1313 extern void disable_branch_tracing(void);
trace_branch_enable(struct trace_array * tr)1314 static inline int trace_branch_enable(struct trace_array *tr)
1315 {
1316 	if (tr->trace_flags & TRACE_ITER_BRANCH)
1317 		return enable_branch_tracing(tr);
1318 	return 0;
1319 }
trace_branch_disable(void)1320 static inline void trace_branch_disable(void)
1321 {
1322 	/* due to races, always disable */
1323 	disable_branch_tracing();
1324 }
1325 #else
trace_branch_enable(struct trace_array * tr)1326 static inline int trace_branch_enable(struct trace_array *tr)
1327 {
1328 	return 0;
1329 }
trace_branch_disable(void)1330 static inline void trace_branch_disable(void)
1331 {
1332 }
1333 #endif /* CONFIG_BRANCH_TRACER */
1334 
1335 /* set ring buffers to default size if not already done so */
1336 int tracing_update_buffers(void);
1337 
1338 struct ftrace_event_field {
1339 	struct list_head	link;
1340 	const char		*name;
1341 	const char		*type;
1342 	int			filter_type;
1343 	int			offset;
1344 	int			size;
1345 	int			is_signed;
1346 };
1347 
1348 struct prog_entry;
1349 
1350 struct event_filter {
1351 	struct prog_entry __rcu	*prog;
1352 	char			*filter_string;
1353 };
1354 
1355 struct event_subsystem {
1356 	struct list_head	list;
1357 	const char		*name;
1358 	struct event_filter	*filter;
1359 	int			ref_count;
1360 };
1361 
1362 struct trace_subsystem_dir {
1363 	struct list_head		list;
1364 	struct event_subsystem		*subsystem;
1365 	struct trace_array		*tr;
1366 	struct dentry			*entry;
1367 	int				ref_count;
1368 	int				nr_events;
1369 };
1370 
1371 extern int call_filter_check_discard(struct trace_event_call *call, void *rec,
1372 				     struct ring_buffer *buffer,
1373 				     struct ring_buffer_event *event);
1374 
1375 void trace_buffer_unlock_commit_regs(struct trace_array *tr,
1376 				     struct ring_buffer *buffer,
1377 				     struct ring_buffer_event *event,
1378 				     unsigned long flags, int pc,
1379 				     struct pt_regs *regs);
1380 
trace_buffer_unlock_commit(struct trace_array * tr,struct ring_buffer * buffer,struct ring_buffer_event * event,unsigned long flags,int pc)1381 static inline void trace_buffer_unlock_commit(struct trace_array *tr,
1382 					      struct ring_buffer *buffer,
1383 					      struct ring_buffer_event *event,
1384 					      unsigned long flags, int pc)
1385 {
1386 	trace_buffer_unlock_commit_regs(tr, buffer, event, flags, pc, NULL);
1387 }
1388 
1389 DECLARE_PER_CPU(struct ring_buffer_event *, trace_buffered_event);
1390 DECLARE_PER_CPU(int, trace_buffered_event_cnt);
1391 void trace_buffered_event_disable(void);
1392 void trace_buffered_event_enable(void);
1393 
1394 static inline void
__trace_event_discard_commit(struct ring_buffer * buffer,struct ring_buffer_event * event)1395 __trace_event_discard_commit(struct ring_buffer *buffer,
1396 			     struct ring_buffer_event *event)
1397 {
1398 	if (this_cpu_read(trace_buffered_event) == event) {
1399 		/* Simply release the temp buffer */
1400 		this_cpu_dec(trace_buffered_event_cnt);
1401 		return;
1402 	}
1403 	ring_buffer_discard_commit(buffer, event);
1404 }
1405 
1406 /*
1407  * Helper function for event_trigger_unlock_commit{_regs}().
1408  * If there are event triggers attached to this event that requires
1409  * filtering against its fields, then they wil be called as the
1410  * entry already holds the field information of the current event.
1411  *
1412  * It also checks if the event should be discarded or not.
1413  * It is to be discarded if the event is soft disabled and the
1414  * event was only recorded to process triggers, or if the event
1415  * filter is active and this event did not match the filters.
1416  *
1417  * Returns true if the event is discarded, false otherwise.
1418  */
1419 static inline bool
__event_trigger_test_discard(struct trace_event_file * file,struct ring_buffer * buffer,struct ring_buffer_event * event,void * entry,enum event_trigger_type * tt)1420 __event_trigger_test_discard(struct trace_event_file *file,
1421 			     struct ring_buffer *buffer,
1422 			     struct ring_buffer_event *event,
1423 			     void *entry,
1424 			     enum event_trigger_type *tt)
1425 {
1426 	unsigned long eflags = file->flags;
1427 
1428 	if (eflags & EVENT_FILE_FL_TRIGGER_COND)
1429 		*tt = event_triggers_call(file, entry, event);
1430 
1431 	if (likely(!(file->flags & (EVENT_FILE_FL_SOFT_DISABLED |
1432 				    EVENT_FILE_FL_FILTERED |
1433 				    EVENT_FILE_FL_PID_FILTER))))
1434 		return false;
1435 
1436 	if (file->flags & EVENT_FILE_FL_SOFT_DISABLED)
1437 		goto discard;
1438 
1439 	if (file->flags & EVENT_FILE_FL_FILTERED &&
1440 	    !filter_match_preds(file->filter, entry))
1441 		goto discard;
1442 
1443 	if ((file->flags & EVENT_FILE_FL_PID_FILTER) &&
1444 	    trace_event_ignore_this_pid(file))
1445 		goto discard;
1446 
1447 	return false;
1448  discard:
1449 	__trace_event_discard_commit(buffer, event);
1450 	return true;
1451 }
1452 
1453 /**
1454  * event_trigger_unlock_commit - handle triggers and finish event commit
1455  * @file: The file pointer assoctiated to the event
1456  * @buffer: The ring buffer that the event is being written to
1457  * @event: The event meta data in the ring buffer
1458  * @entry: The event itself
1459  * @irq_flags: The state of the interrupts at the start of the event
1460  * @pc: The state of the preempt count at the start of the event.
1461  *
1462  * This is a helper function to handle triggers that require data
1463  * from the event itself. It also tests the event against filters and
1464  * if the event is soft disabled and should be discarded.
1465  */
1466 static inline void
event_trigger_unlock_commit(struct trace_event_file * file,struct ring_buffer * buffer,struct ring_buffer_event * event,void * entry,unsigned long irq_flags,int pc)1467 event_trigger_unlock_commit(struct trace_event_file *file,
1468 			    struct ring_buffer *buffer,
1469 			    struct ring_buffer_event *event,
1470 			    void *entry, unsigned long irq_flags, int pc)
1471 {
1472 	enum event_trigger_type tt = ETT_NONE;
1473 
1474 	if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1475 		trace_buffer_unlock_commit(file->tr, buffer, event, irq_flags, pc);
1476 
1477 	if (tt)
1478 		event_triggers_post_call(file, tt);
1479 }
1480 
1481 /**
1482  * event_trigger_unlock_commit_regs - handle triggers and finish event commit
1483  * @file: The file pointer assoctiated to the event
1484  * @buffer: The ring buffer that the event is being written to
1485  * @event: The event meta data in the ring buffer
1486  * @entry: The event itself
1487  * @irq_flags: The state of the interrupts at the start of the event
1488  * @pc: The state of the preempt count at the start of the event.
1489  *
1490  * This is a helper function to handle triggers that require data
1491  * from the event itself. It also tests the event against filters and
1492  * if the event is soft disabled and should be discarded.
1493  *
1494  * Same as event_trigger_unlock_commit() but calls
1495  * trace_buffer_unlock_commit_regs() instead of trace_buffer_unlock_commit().
1496  */
1497 static inline void
event_trigger_unlock_commit_regs(struct trace_event_file * file,struct ring_buffer * buffer,struct ring_buffer_event * event,void * entry,unsigned long irq_flags,int pc,struct pt_regs * regs)1498 event_trigger_unlock_commit_regs(struct trace_event_file *file,
1499 				 struct ring_buffer *buffer,
1500 				 struct ring_buffer_event *event,
1501 				 void *entry, unsigned long irq_flags, int pc,
1502 				 struct pt_regs *regs)
1503 {
1504 	enum event_trigger_type tt = ETT_NONE;
1505 
1506 	if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1507 		trace_buffer_unlock_commit_regs(file->tr, buffer, event,
1508 						irq_flags, pc, regs);
1509 
1510 	if (tt)
1511 		event_triggers_post_call(file, tt);
1512 }
1513 
1514 #define FILTER_PRED_INVALID	((unsigned short)-1)
1515 #define FILTER_PRED_IS_RIGHT	(1 << 15)
1516 #define FILTER_PRED_FOLD	(1 << 15)
1517 
1518 /*
1519  * The max preds is the size of unsigned short with
1520  * two flags at the MSBs. One bit is used for both the IS_RIGHT
1521  * and FOLD flags. The other is reserved.
1522  *
1523  * 2^14 preds is way more than enough.
1524  */
1525 #define MAX_FILTER_PRED		16384
1526 
1527 struct filter_pred;
1528 struct regex;
1529 
1530 typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event);
1531 
1532 typedef int (*regex_match_func)(char *str, struct regex *r, int len);
1533 
1534 enum regex_type {
1535 	MATCH_FULL = 0,
1536 	MATCH_FRONT_ONLY,
1537 	MATCH_MIDDLE_ONLY,
1538 	MATCH_END_ONLY,
1539 	MATCH_GLOB,
1540 	MATCH_INDEX,
1541 };
1542 
1543 struct regex {
1544 	char			pattern[MAX_FILTER_STR_VAL];
1545 	int			len;
1546 	int			field_len;
1547 	regex_match_func	match;
1548 };
1549 
1550 struct filter_pred {
1551 	filter_pred_fn_t 	fn;
1552 	u64 			val;
1553 	struct regex		regex;
1554 	unsigned short		*ops;
1555 	struct ftrace_event_field *field;
1556 	int 			offset;
1557 	int			not;
1558 	int 			op;
1559 };
1560 
is_string_field(struct ftrace_event_field * field)1561 static inline bool is_string_field(struct ftrace_event_field *field)
1562 {
1563 	return field->filter_type == FILTER_DYN_STRING ||
1564 	       field->filter_type == FILTER_STATIC_STRING ||
1565 	       field->filter_type == FILTER_PTR_STRING ||
1566 	       field->filter_type == FILTER_COMM;
1567 }
1568 
is_function_field(struct ftrace_event_field * field)1569 static inline bool is_function_field(struct ftrace_event_field *field)
1570 {
1571 	return field->filter_type == FILTER_TRACE_FN;
1572 }
1573 
1574 extern enum regex_type
1575 filter_parse_regex(char *buff, int len, char **search, int *not);
1576 extern void print_event_filter(struct trace_event_file *file,
1577 			       struct trace_seq *s);
1578 extern int apply_event_filter(struct trace_event_file *file,
1579 			      char *filter_string);
1580 extern int apply_subsystem_event_filter(struct trace_subsystem_dir *dir,
1581 					char *filter_string);
1582 extern void print_subsystem_event_filter(struct event_subsystem *system,
1583 					 struct trace_seq *s);
1584 extern int filter_assign_type(const char *type);
1585 extern int create_event_filter(struct trace_array *tr,
1586 			       struct trace_event_call *call,
1587 			       char *filter_str, bool set_str,
1588 			       struct event_filter **filterp);
1589 extern void free_event_filter(struct event_filter *filter);
1590 
1591 struct ftrace_event_field *
1592 trace_find_event_field(struct trace_event_call *call, char *name);
1593 
1594 extern void trace_event_enable_cmd_record(bool enable);
1595 extern void trace_event_enable_tgid_record(bool enable);
1596 
1597 extern int event_trace_init(void);
1598 extern int init_events(void);
1599 extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
1600 extern int event_trace_del_tracer(struct trace_array *tr);
1601 
1602 extern struct trace_event_file *__find_event_file(struct trace_array *tr,
1603 						  const char *system,
1604 						  const char *event);
1605 extern struct trace_event_file *find_event_file(struct trace_array *tr,
1606 						const char *system,
1607 						const char *event);
1608 
event_file_data(struct file * filp)1609 static inline void *event_file_data(struct file *filp)
1610 {
1611 	return READ_ONCE(file_inode(filp)->i_private);
1612 }
1613 
1614 extern struct mutex event_mutex;
1615 extern struct list_head ftrace_events;
1616 
1617 extern const struct file_operations event_trigger_fops;
1618 extern const struct file_operations event_hist_fops;
1619 
1620 #ifdef CONFIG_HIST_TRIGGERS
1621 extern int register_trigger_hist_cmd(void);
1622 extern int register_trigger_hist_enable_disable_cmds(void);
1623 #else
register_trigger_hist_cmd(void)1624 static inline int register_trigger_hist_cmd(void) { return 0; }
register_trigger_hist_enable_disable_cmds(void)1625 static inline int register_trigger_hist_enable_disable_cmds(void) { return 0; }
1626 #endif
1627 
1628 extern int register_trigger_cmds(void);
1629 extern void clear_event_triggers(struct trace_array *tr);
1630 
1631 struct event_trigger_data {
1632 	unsigned long			count;
1633 	int				ref;
1634 	struct event_trigger_ops	*ops;
1635 	struct event_command		*cmd_ops;
1636 	struct event_filter __rcu	*filter;
1637 	char				*filter_str;
1638 	void				*private_data;
1639 	bool				paused;
1640 	bool				paused_tmp;
1641 	struct list_head		list;
1642 	char				*name;
1643 	struct list_head		named_list;
1644 	struct event_trigger_data	*named_data;
1645 };
1646 
1647 /* Avoid typos */
1648 #define ENABLE_EVENT_STR	"enable_event"
1649 #define DISABLE_EVENT_STR	"disable_event"
1650 #define ENABLE_HIST_STR		"enable_hist"
1651 #define DISABLE_HIST_STR	"disable_hist"
1652 
1653 struct enable_trigger_data {
1654 	struct trace_event_file		*file;
1655 	bool				enable;
1656 	bool				hist;
1657 };
1658 
1659 extern int event_enable_trigger_print(struct seq_file *m,
1660 				      struct event_trigger_ops *ops,
1661 				      struct event_trigger_data *data);
1662 extern void event_enable_trigger_free(struct event_trigger_ops *ops,
1663 				      struct event_trigger_data *data);
1664 extern int event_enable_trigger_func(struct event_command *cmd_ops,
1665 				     struct trace_event_file *file,
1666 				     char *glob, char *cmd, char *param);
1667 extern int event_enable_register_trigger(char *glob,
1668 					 struct event_trigger_ops *ops,
1669 					 struct event_trigger_data *data,
1670 					 struct trace_event_file *file);
1671 extern void event_enable_unregister_trigger(char *glob,
1672 					    struct event_trigger_ops *ops,
1673 					    struct event_trigger_data *test,
1674 					    struct trace_event_file *file);
1675 extern void trigger_data_free(struct event_trigger_data *data);
1676 extern int event_trigger_init(struct event_trigger_ops *ops,
1677 			      struct event_trigger_data *data);
1678 extern int trace_event_trigger_enable_disable(struct trace_event_file *file,
1679 					      int trigger_enable);
1680 extern void update_cond_flag(struct trace_event_file *file);
1681 extern int set_trigger_filter(char *filter_str,
1682 			      struct event_trigger_data *trigger_data,
1683 			      struct trace_event_file *file);
1684 extern struct event_trigger_data *find_named_trigger(const char *name);
1685 extern bool is_named_trigger(struct event_trigger_data *test);
1686 extern int save_named_trigger(const char *name,
1687 			      struct event_trigger_data *data);
1688 extern void del_named_trigger(struct event_trigger_data *data);
1689 extern void pause_named_trigger(struct event_trigger_data *data);
1690 extern void unpause_named_trigger(struct event_trigger_data *data);
1691 extern void set_named_trigger_data(struct event_trigger_data *data,
1692 				   struct event_trigger_data *named_data);
1693 extern struct event_trigger_data *
1694 get_named_trigger_data(struct event_trigger_data *data);
1695 extern int register_event_command(struct event_command *cmd);
1696 extern int unregister_event_command(struct event_command *cmd);
1697 extern int register_trigger_hist_enable_disable_cmds(void);
1698 
1699 /**
1700  * struct event_trigger_ops - callbacks for trace event triggers
1701  *
1702  * The methods in this structure provide per-event trigger hooks for
1703  * various trigger operations.
1704  *
1705  * All the methods below, except for @init() and @free(), must be
1706  * implemented.
1707  *
1708  * @func: The trigger 'probe' function called when the triggering
1709  *	event occurs.  The data passed into this callback is the data
1710  *	that was supplied to the event_command @reg() function that
1711  *	registered the trigger (see struct event_command) along with
1712  *	the trace record, rec.
1713  *
1714  * @init: An optional initialization function called for the trigger
1715  *	when the trigger is registered (via the event_command reg()
1716  *	function).  This can be used to perform per-trigger
1717  *	initialization such as incrementing a per-trigger reference
1718  *	count, for instance.  This is usually implemented by the
1719  *	generic utility function @event_trigger_init() (see
1720  *	trace_event_triggers.c).
1721  *
1722  * @free: An optional de-initialization function called for the
1723  *	trigger when the trigger is unregistered (via the
1724  *	event_command @reg() function).  This can be used to perform
1725  *	per-trigger de-initialization such as decrementing a
1726  *	per-trigger reference count and freeing corresponding trigger
1727  *	data, for instance.  This is usually implemented by the
1728  *	generic utility function @event_trigger_free() (see
1729  *	trace_event_triggers.c).
1730  *
1731  * @print: The callback function invoked to have the trigger print
1732  *	itself.  This is usually implemented by a wrapper function
1733  *	that calls the generic utility function @event_trigger_print()
1734  *	(see trace_event_triggers.c).
1735  */
1736 struct event_trigger_ops {
1737 	void			(*func)(struct event_trigger_data *data,
1738 					void *rec,
1739 					struct ring_buffer_event *rbe);
1740 	int			(*init)(struct event_trigger_ops *ops,
1741 					struct event_trigger_data *data);
1742 	void			(*free)(struct event_trigger_ops *ops,
1743 					struct event_trigger_data *data);
1744 	int			(*print)(struct seq_file *m,
1745 					 struct event_trigger_ops *ops,
1746 					 struct event_trigger_data *data);
1747 };
1748 
1749 /**
1750  * struct event_command - callbacks and data members for event commands
1751  *
1752  * Event commands are invoked by users by writing the command name
1753  * into the 'trigger' file associated with a trace event.  The
1754  * parameters associated with a specific invocation of an event
1755  * command are used to create an event trigger instance, which is
1756  * added to the list of trigger instances associated with that trace
1757  * event.  When the event is hit, the set of triggers associated with
1758  * that event is invoked.
1759  *
1760  * The data members in this structure provide per-event command data
1761  * for various event commands.
1762  *
1763  * All the data members below, except for @post_trigger, must be set
1764  * for each event command.
1765  *
1766  * @name: The unique name that identifies the event command.  This is
1767  *	the name used when setting triggers via trigger files.
1768  *
1769  * @trigger_type: A unique id that identifies the event command
1770  *	'type'.  This value has two purposes, the first to ensure that
1771  *	only one trigger of the same type can be set at a given time
1772  *	for a particular event e.g. it doesn't make sense to have both
1773  *	a traceon and traceoff trigger attached to a single event at
1774  *	the same time, so traceon and traceoff have the same type
1775  *	though they have different names.  The @trigger_type value is
1776  *	also used as a bit value for deferring the actual trigger
1777  *	action until after the current event is finished.  Some
1778  *	commands need to do this if they themselves log to the trace
1779  *	buffer (see the @post_trigger() member below).  @trigger_type
1780  *	values are defined by adding new values to the trigger_type
1781  *	enum in include/linux/trace_events.h.
1782  *
1783  * @flags: See the enum event_command_flags below.
1784  *
1785  * All the methods below, except for @set_filter() and @unreg_all(),
1786  * must be implemented.
1787  *
1788  * @func: The callback function responsible for parsing and
1789  *	registering the trigger written to the 'trigger' file by the
1790  *	user.  It allocates the trigger instance and registers it with
1791  *	the appropriate trace event.  It makes use of the other
1792  *	event_command callback functions to orchestrate this, and is
1793  *	usually implemented by the generic utility function
1794  *	@event_trigger_callback() (see trace_event_triggers.c).
1795  *
1796  * @reg: Adds the trigger to the list of triggers associated with the
1797  *	event, and enables the event trigger itself, after
1798  *	initializing it (via the event_trigger_ops @init() function).
1799  *	This is also where commands can use the @trigger_type value to
1800  *	make the decision as to whether or not multiple instances of
1801  *	the trigger should be allowed.  This is usually implemented by
1802  *	the generic utility function @register_trigger() (see
1803  *	trace_event_triggers.c).
1804  *
1805  * @unreg: Removes the trigger from the list of triggers associated
1806  *	with the event, and disables the event trigger itself, after
1807  *	initializing it (via the event_trigger_ops @free() function).
1808  *	This is usually implemented by the generic utility function
1809  *	@unregister_trigger() (see trace_event_triggers.c).
1810  *
1811  * @unreg_all: An optional function called to remove all the triggers
1812  *	from the list of triggers associated with the event.  Called
1813  *	when a trigger file is opened in truncate mode.
1814  *
1815  * @set_filter: An optional function called to parse and set a filter
1816  *	for the trigger.  If no @set_filter() method is set for the
1817  *	event command, filters set by the user for the command will be
1818  *	ignored.  This is usually implemented by the generic utility
1819  *	function @set_trigger_filter() (see trace_event_triggers.c).
1820  *
1821  * @get_trigger_ops: The callback function invoked to retrieve the
1822  *	event_trigger_ops implementation associated with the command.
1823  */
1824 struct event_command {
1825 	struct list_head	list;
1826 	char			*name;
1827 	enum event_trigger_type	trigger_type;
1828 	int			flags;
1829 	int			(*func)(struct event_command *cmd_ops,
1830 					struct trace_event_file *file,
1831 					char *glob, char *cmd, char *params);
1832 	int			(*reg)(char *glob,
1833 				       struct event_trigger_ops *ops,
1834 				       struct event_trigger_data *data,
1835 				       struct trace_event_file *file);
1836 	void			(*unreg)(char *glob,
1837 					 struct event_trigger_ops *ops,
1838 					 struct event_trigger_data *data,
1839 					 struct trace_event_file *file);
1840 	void			(*unreg_all)(struct trace_event_file *file);
1841 	int			(*set_filter)(char *filter_str,
1842 					      struct event_trigger_data *data,
1843 					      struct trace_event_file *file);
1844 	struct event_trigger_ops *(*get_trigger_ops)(char *cmd, char *param);
1845 };
1846 
1847 /**
1848  * enum event_command_flags - flags for struct event_command
1849  *
1850  * @POST_TRIGGER: A flag that says whether or not this command needs
1851  *	to have its action delayed until after the current event has
1852  *	been closed.  Some triggers need to avoid being invoked while
1853  *	an event is currently in the process of being logged, since
1854  *	the trigger may itself log data into the trace buffer.  Thus
1855  *	we make sure the current event is committed before invoking
1856  *	those triggers.  To do that, the trigger invocation is split
1857  *	in two - the first part checks the filter using the current
1858  *	trace record; if a command has the @post_trigger flag set, it
1859  *	sets a bit for itself in the return value, otherwise it
1860  *	directly invokes the trigger.  Once all commands have been
1861  *	either invoked or set their return flag, the current record is
1862  *	either committed or discarded.  At that point, if any commands
1863  *	have deferred their triggers, those commands are finally
1864  *	invoked following the close of the current event.  In other
1865  *	words, if the event_trigger_ops @func() probe implementation
1866  *	itself logs to the trace buffer, this flag should be set,
1867  *	otherwise it can be left unspecified.
1868  *
1869  * @NEEDS_REC: A flag that says whether or not this command needs
1870  *	access to the trace record in order to perform its function,
1871  *	regardless of whether or not it has a filter associated with
1872  *	it (filters make a trigger require access to the trace record
1873  *	but are not always present).
1874  */
1875 enum event_command_flags {
1876 	EVENT_CMD_FL_POST_TRIGGER	= 1,
1877 	EVENT_CMD_FL_NEEDS_REC		= 2,
1878 };
1879 
event_command_post_trigger(struct event_command * cmd_ops)1880 static inline bool event_command_post_trigger(struct event_command *cmd_ops)
1881 {
1882 	return cmd_ops->flags & EVENT_CMD_FL_POST_TRIGGER;
1883 }
1884 
event_command_needs_rec(struct event_command * cmd_ops)1885 static inline bool event_command_needs_rec(struct event_command *cmd_ops)
1886 {
1887 	return cmd_ops->flags & EVENT_CMD_FL_NEEDS_REC;
1888 }
1889 
1890 extern int trace_event_enable_disable(struct trace_event_file *file,
1891 				      int enable, int soft_disable);
1892 extern int tracing_alloc_snapshot(void);
1893 extern void tracing_snapshot_cond(struct trace_array *tr, void *cond_data);
1894 extern int tracing_snapshot_cond_enable(struct trace_array *tr, void *cond_data, cond_update_fn_t update);
1895 
1896 extern int tracing_snapshot_cond_disable(struct trace_array *tr);
1897 extern void *tracing_cond_snapshot_data(struct trace_array *tr);
1898 
1899 extern const char *__start___trace_bprintk_fmt[];
1900 extern const char *__stop___trace_bprintk_fmt[];
1901 
1902 extern const char *__start___tracepoint_str[];
1903 extern const char *__stop___tracepoint_str[];
1904 
1905 void trace_printk_control(bool enabled);
1906 void trace_printk_init_buffers(void);
1907 void trace_printk_start_comm(void);
1908 int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set);
1909 int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled);
1910 
1911 #define MAX_EVENT_NAME_LEN	64
1912 
1913 extern int trace_run_command(const char *buf, int (*createfn)(int, char**));
1914 extern ssize_t trace_parse_run_command(struct file *file,
1915 		const char __user *buffer, size_t count, loff_t *ppos,
1916 		int (*createfn)(int, char**));
1917 
1918 extern unsigned int err_pos(char *cmd, const char *str);
1919 extern void tracing_log_err(struct trace_array *tr,
1920 			    const char *loc, const char *cmd,
1921 			    const char **errs, u8 type, u8 pos);
1922 
1923 /*
1924  * Normal trace_printk() and friends allocates special buffers
1925  * to do the manipulation, as well as saves the print formats
1926  * into sections to display. But the trace infrastructure wants
1927  * to use these without the added overhead at the price of being
1928  * a bit slower (used mainly for warnings, where we don't care
1929  * about performance). The internal_trace_puts() is for such
1930  * a purpose.
1931  */
1932 #define internal_trace_puts(str) __trace_puts(_THIS_IP_, str, strlen(str))
1933 
1934 #undef FTRACE_ENTRY
1935 #define FTRACE_ENTRY(call, struct_name, id, tstruct, print, filter)	\
1936 	extern struct trace_event_call					\
1937 	__aligned(4) event_##call;
1938 #undef FTRACE_ENTRY_DUP
1939 #define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print, filter)	\
1940 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print), \
1941 		     filter)
1942 #undef FTRACE_ENTRY_PACKED
1943 #define FTRACE_ENTRY_PACKED(call, struct_name, id, tstruct, print, filter) \
1944 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print), \
1945 		     filter)
1946 
1947 #include "trace_entries.h"
1948 
1949 #if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_FUNCTION_TRACER)
1950 int perf_ftrace_event_register(struct trace_event_call *call,
1951 			       enum trace_reg type, void *data);
1952 #else
1953 #define perf_ftrace_event_register NULL
1954 #endif
1955 
1956 #ifdef CONFIG_FTRACE_SYSCALLS
1957 void init_ftrace_syscalls(void);
1958 const char *get_syscall_name(int syscall);
1959 #else
init_ftrace_syscalls(void)1960 static inline void init_ftrace_syscalls(void) { }
get_syscall_name(int syscall)1961 static inline const char *get_syscall_name(int syscall)
1962 {
1963 	return NULL;
1964 }
1965 #endif
1966 
1967 #ifdef CONFIG_EVENT_TRACING
1968 void trace_event_init(void);
1969 void trace_event_eval_update(struct trace_eval_map **map, int len);
1970 #else
trace_event_init(void)1971 static inline void __init trace_event_init(void) { }
trace_event_eval_update(struct trace_eval_map ** map,int len)1972 static inline void trace_event_eval_update(struct trace_eval_map **map, int len) { }
1973 #endif
1974 
1975 #ifdef CONFIG_TRACER_SNAPSHOT
1976 void tracing_snapshot_instance(struct trace_array *tr);
1977 int tracing_alloc_snapshot_instance(struct trace_array *tr);
1978 #else
tracing_snapshot_instance(struct trace_array * tr)1979 static inline void tracing_snapshot_instance(struct trace_array *tr) { }
tracing_alloc_snapshot_instance(struct trace_array * tr)1980 static inline int tracing_alloc_snapshot_instance(struct trace_array *tr)
1981 {
1982 	return 0;
1983 }
1984 #endif
1985 
1986 #ifdef CONFIG_PREEMPT_TRACER
1987 void tracer_preempt_on(unsigned long a0, unsigned long a1);
1988 void tracer_preempt_off(unsigned long a0, unsigned long a1);
1989 #else
tracer_preempt_on(unsigned long a0,unsigned long a1)1990 static inline void tracer_preempt_on(unsigned long a0, unsigned long a1) { }
tracer_preempt_off(unsigned long a0,unsigned long a1)1991 static inline void tracer_preempt_off(unsigned long a0, unsigned long a1) { }
1992 #endif
1993 #ifdef CONFIG_IRQSOFF_TRACER
1994 void tracer_hardirqs_on(unsigned long a0, unsigned long a1);
1995 void tracer_hardirqs_off(unsigned long a0, unsigned long a1);
1996 #else
tracer_hardirqs_on(unsigned long a0,unsigned long a1)1997 static inline void tracer_hardirqs_on(unsigned long a0, unsigned long a1) { }
tracer_hardirqs_off(unsigned long a0,unsigned long a1)1998 static inline void tracer_hardirqs_off(unsigned long a0, unsigned long a1) { }
1999 #endif
2000 
2001 extern struct trace_iterator *tracepoint_print_iter;
2002 
2003 /*
2004  * Reset the state of the trace_iterator so that it can read consumed data.
2005  * Normally, the trace_iterator is used for reading the data when it is not
2006  * consumed, and must retain state.
2007  */
trace_iterator_reset(struct trace_iterator * iter)2008 static __always_inline void trace_iterator_reset(struct trace_iterator *iter)
2009 {
2010 	const size_t offset = offsetof(struct trace_iterator, seq);
2011 
2012 	/*
2013 	 * Keep gcc from complaining about overwriting more than just one
2014 	 * member in the structure.
2015 	 */
2016 	memset((char *)iter + offset, 0, sizeof(struct trace_iterator) - offset);
2017 
2018 	iter->pos = -1;
2019 }
2020 
2021 #endif /* _LINUX_KERNEL_TRACE_H */
2022