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