xref: /linux/kernel/trace/trace.h (revision 498d319bb512992ef0784c278fa03679f2f5649d)
1 #ifndef _LINUX_KERNEL_TRACE_H
2 #define _LINUX_KERNEL_TRACE_H
3 
4 #include <linux/fs.h>
5 #include <linux/atomic.h>
6 #include <linux/sched.h>
7 #include <linux/clocksource.h>
8 #include <linux/ring_buffer.h>
9 #include <linux/mmiotrace.h>
10 #include <linux/tracepoint.h>
11 #include <linux/ftrace.h>
12 #include <linux/hw_breakpoint.h>
13 #include <linux/trace_seq.h>
14 #include <linux/ftrace_event.h>
15 
16 #ifdef CONFIG_FTRACE_SYSCALLS
17 #include <asm/unistd.h>		/* For NR_SYSCALLS	     */
18 #include <asm/syscall.h>	/* some archs define it here */
19 #endif
20 
21 enum trace_type {
22 	__TRACE_FIRST_TYPE = 0,
23 
24 	TRACE_FN,
25 	TRACE_CTX,
26 	TRACE_WAKE,
27 	TRACE_STACK,
28 	TRACE_PRINT,
29 	TRACE_BPRINT,
30 	TRACE_MMIO_RW,
31 	TRACE_MMIO_MAP,
32 	TRACE_BRANCH,
33 	TRACE_GRAPH_RET,
34 	TRACE_GRAPH_ENT,
35 	TRACE_USER_STACK,
36 	TRACE_BLK,
37 	TRACE_BPUTS,
38 
39 	__TRACE_LAST_TYPE,
40 };
41 
42 
43 #undef __field
44 #define __field(type, item)		type	item;
45 
46 #undef __field_struct
47 #define __field_struct(type, item)	__field(type, item)
48 
49 #undef __field_desc
50 #define __field_desc(type, container, item)
51 
52 #undef __array
53 #define __array(type, item, size)	type	item[size];
54 
55 #undef __array_desc
56 #define __array_desc(type, container, item, size)
57 
58 #undef __dynamic_array
59 #define __dynamic_array(type, item)	type	item[];
60 
61 #undef F_STRUCT
62 #define F_STRUCT(args...)		args
63 
64 #undef FTRACE_ENTRY
65 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print, filter)	\
66 	struct struct_name {						\
67 		struct trace_entry	ent;				\
68 		tstruct							\
69 	}
70 
71 #undef TP_ARGS
72 #define TP_ARGS(args...)	args
73 
74 #undef FTRACE_ENTRY_DUP
75 #define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk, filter)
76 
77 #undef FTRACE_ENTRY_REG
78 #define FTRACE_ENTRY_REG(name, struct_name, id, tstruct, print,	\
79 			 filter, regfn) \
80 	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print), \
81 		     filter)
82 
83 #include "trace_entries.h"
84 
85 /*
86  * syscalls are special, and need special handling, this is why
87  * they are not included in trace_entries.h
88  */
89 struct syscall_trace_enter {
90 	struct trace_entry	ent;
91 	int			nr;
92 	unsigned long		args[];
93 };
94 
95 struct syscall_trace_exit {
96 	struct trace_entry	ent;
97 	int			nr;
98 	long			ret;
99 };
100 
101 struct kprobe_trace_entry_head {
102 	struct trace_entry	ent;
103 	unsigned long		ip;
104 };
105 
106 struct kretprobe_trace_entry_head {
107 	struct trace_entry	ent;
108 	unsigned long		func;
109 	unsigned long		ret_ip;
110 };
111 
112 /*
113  * trace_flag_type is an enumeration that holds different
114  * states when a trace occurs. These are:
115  *  IRQS_OFF		- interrupts were disabled
116  *  IRQS_NOSUPPORT	- arch does not support irqs_disabled_flags
117  *  NEED_RESCHED	- reschedule is requested
118  *  HARDIRQ		- inside an interrupt handler
119  *  SOFTIRQ		- inside a softirq handler
120  */
121 enum trace_flag_type {
122 	TRACE_FLAG_IRQS_OFF		= 0x01,
123 	TRACE_FLAG_IRQS_NOSUPPORT	= 0x02,
124 	TRACE_FLAG_NEED_RESCHED		= 0x04,
125 	TRACE_FLAG_HARDIRQ		= 0x08,
126 	TRACE_FLAG_SOFTIRQ		= 0x10,
127 	TRACE_FLAG_PREEMPT_RESCHED	= 0x20,
128 };
129 
130 #define TRACE_BUF_SIZE		1024
131 
132 struct trace_array;
133 
134 /*
135  * The CPU trace array - it consists of thousands of trace entries
136  * plus some other descriptor data: (for example which task started
137  * the trace, etc.)
138  */
139 struct trace_array_cpu {
140 	atomic_t		disabled;
141 	void			*buffer_page;	/* ring buffer spare */
142 
143 	unsigned long		entries;
144 	unsigned long		saved_latency;
145 	unsigned long		critical_start;
146 	unsigned long		critical_end;
147 	unsigned long		critical_sequence;
148 	unsigned long		nice;
149 	unsigned long		policy;
150 	unsigned long		rt_priority;
151 	unsigned long		skipped_entries;
152 	cycle_t			preempt_timestamp;
153 	pid_t			pid;
154 	kuid_t			uid;
155 	char			comm[TASK_COMM_LEN];
156 };
157 
158 struct tracer;
159 
160 struct trace_buffer {
161 	struct trace_array		*tr;
162 	struct ring_buffer		*buffer;
163 	struct trace_array_cpu __percpu	*data;
164 	cycle_t				time_start;
165 	int				cpu;
166 };
167 
168 /*
169  * The trace array - an array of per-CPU trace arrays. This is the
170  * highest level data structure that individual tracers deal with.
171  * They have on/off state as well:
172  */
173 struct trace_array {
174 	struct list_head	list;
175 	char			*name;
176 	struct trace_buffer	trace_buffer;
177 #ifdef CONFIG_TRACER_MAX_TRACE
178 	/*
179 	 * The max_buffer is used to snapshot the trace when a maximum
180 	 * latency is reached, or when the user initiates a snapshot.
181 	 * Some tracers will use this to store a maximum trace while
182 	 * it continues examining live traces.
183 	 *
184 	 * The buffers for the max_buffer are set up the same as the trace_buffer
185 	 * When a snapshot is taken, the buffer of the max_buffer is swapped
186 	 * with the buffer of the trace_buffer and the buffers are reset for
187 	 * the trace_buffer so the tracing can continue.
188 	 */
189 	struct trace_buffer	max_buffer;
190 	bool			allocated_snapshot;
191 #endif
192 	int			buffer_disabled;
193 #ifdef CONFIG_FTRACE_SYSCALLS
194 	int			sys_refcount_enter;
195 	int			sys_refcount_exit;
196 	DECLARE_BITMAP(enabled_enter_syscalls, NR_syscalls);
197 	DECLARE_BITMAP(enabled_exit_syscalls, NR_syscalls);
198 #endif
199 	int			stop_count;
200 	int			clock_id;
201 	struct tracer		*current_trace;
202 	unsigned int		flags;
203 	raw_spinlock_t		start_lock;
204 	struct dentry		*dir;
205 	struct dentry		*options;
206 	struct dentry		*percpu_dir;
207 	struct dentry		*event_dir;
208 	struct list_head	systems;
209 	struct list_head	events;
210 	cpumask_var_t		tracing_cpumask; /* only trace on set CPUs */
211 	int			ref;
212 };
213 
214 enum {
215 	TRACE_ARRAY_FL_GLOBAL	= (1 << 0)
216 };
217 
218 extern struct list_head ftrace_trace_arrays;
219 
220 extern struct mutex trace_types_lock;
221 
222 extern int trace_array_get(struct trace_array *tr);
223 extern void trace_array_put(struct trace_array *tr);
224 
225 /*
226  * The global tracer (top) should be the first trace array added,
227  * but we check the flag anyway.
228  */
229 static inline struct trace_array *top_trace_array(void)
230 {
231 	struct trace_array *tr;
232 
233 	tr = list_entry(ftrace_trace_arrays.prev,
234 			typeof(*tr), list);
235 	WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
236 	return tr;
237 }
238 
239 #define FTRACE_CMP_TYPE(var, type) \
240 	__builtin_types_compatible_p(typeof(var), type *)
241 
242 #undef IF_ASSIGN
243 #define IF_ASSIGN(var, entry, etype, id)		\
244 	if (FTRACE_CMP_TYPE(var, etype)) {		\
245 		var = (typeof(var))(entry);		\
246 		WARN_ON(id && (entry)->type != id);	\
247 		break;					\
248 	}
249 
250 /* Will cause compile errors if type is not found. */
251 extern void __ftrace_bad_type(void);
252 
253 /*
254  * The trace_assign_type is a verifier that the entry type is
255  * the same as the type being assigned. To add new types simply
256  * add a line with the following format:
257  *
258  * IF_ASSIGN(var, ent, type, id);
259  *
260  *  Where "type" is the trace type that includes the trace_entry
261  *  as the "ent" item. And "id" is the trace identifier that is
262  *  used in the trace_type enum.
263  *
264  *  If the type can have more than one id, then use zero.
265  */
266 #define trace_assign_type(var, ent)					\
267 	do {								\
268 		IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);	\
269 		IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);	\
270 		IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);	\
271 		IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
272 		IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);	\
273 		IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT);	\
274 		IF_ASSIGN(var, ent, struct bputs_entry, TRACE_BPUTS);	\
275 		IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,		\
276 			  TRACE_MMIO_RW);				\
277 		IF_ASSIGN(var, ent, struct trace_mmiotrace_map,		\
278 			  TRACE_MMIO_MAP);				\
279 		IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
280 		IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,	\
281 			  TRACE_GRAPH_ENT);		\
282 		IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,	\
283 			  TRACE_GRAPH_RET);		\
284 		__ftrace_bad_type();					\
285 	} while (0)
286 
287 /*
288  * An option specific to a tracer. This is a boolean value.
289  * The bit is the bit index that sets its value on the
290  * flags value in struct tracer_flags.
291  */
292 struct tracer_opt {
293 	const char	*name; /* Will appear on the trace_options file */
294 	u32		bit; /* Mask assigned in val field in tracer_flags */
295 };
296 
297 /*
298  * The set of specific options for a tracer. Your tracer
299  * have to set the initial value of the flags val.
300  */
301 struct tracer_flags {
302 	u32			val;
303 	struct tracer_opt	*opts;
304 };
305 
306 /* Makes more easy to define a tracer opt */
307 #define TRACER_OPT(s, b)	.name = #s, .bit = b
308 
309 
310 /**
311  * struct tracer - a specific tracer and its callbacks to interact with debugfs
312  * @name: the name chosen to select it on the available_tracers file
313  * @init: called when one switches to this tracer (echo name > current_tracer)
314  * @reset: called when one switches to another tracer
315  * @start: called when tracing is unpaused (echo 1 > tracing_enabled)
316  * @stop: called when tracing is paused (echo 0 > tracing_enabled)
317  * @open: called when the trace file is opened
318  * @pipe_open: called when the trace_pipe file is opened
319  * @wait_pipe: override how the user waits for traces on trace_pipe
320  * @close: called when the trace file is released
321  * @pipe_close: called when the trace_pipe file is released
322  * @read: override the default read callback on trace_pipe
323  * @splice_read: override the default splice_read callback on trace_pipe
324  * @selftest: selftest to run on boot (see trace_selftest.c)
325  * @print_headers: override the first lines that describe your columns
326  * @print_line: callback that prints a trace
327  * @set_flag: signals one of your private flags changed (trace_options file)
328  * @flags: your private flags
329  */
330 struct tracer {
331 	const char		*name;
332 	int			(*init)(struct trace_array *tr);
333 	void			(*reset)(struct trace_array *tr);
334 	void			(*start)(struct trace_array *tr);
335 	void			(*stop)(struct trace_array *tr);
336 	void			(*open)(struct trace_iterator *iter);
337 	void			(*pipe_open)(struct trace_iterator *iter);
338 	void			(*wait_pipe)(struct trace_iterator *iter);
339 	void			(*close)(struct trace_iterator *iter);
340 	void			(*pipe_close)(struct trace_iterator *iter);
341 	ssize_t			(*read)(struct trace_iterator *iter,
342 					struct file *filp, char __user *ubuf,
343 					size_t cnt, loff_t *ppos);
344 	ssize_t			(*splice_read)(struct trace_iterator *iter,
345 					       struct file *filp,
346 					       loff_t *ppos,
347 					       struct pipe_inode_info *pipe,
348 					       size_t len,
349 					       unsigned int flags);
350 #ifdef CONFIG_FTRACE_STARTUP_TEST
351 	int			(*selftest)(struct tracer *trace,
352 					    struct trace_array *tr);
353 #endif
354 	void			(*print_header)(struct seq_file *m);
355 	enum print_line_t	(*print_line)(struct trace_iterator *iter);
356 	/* If you handled the flag setting, return 0 */
357 	int			(*set_flag)(u32 old_flags, u32 bit, int set);
358 	/* Return 0 if OK with change, else return non-zero */
359 	int			(*flag_changed)(struct tracer *tracer,
360 						u32 mask, int set);
361 	struct tracer		*next;
362 	struct tracer_flags	*flags;
363 	bool			print_max;
364 	bool			enabled;
365 #ifdef CONFIG_TRACER_MAX_TRACE
366 	bool			use_max_tr;
367 #endif
368 };
369 
370 
371 /* Only current can touch trace_recursion */
372 
373 /*
374  * For function tracing recursion:
375  *  The order of these bits are important.
376  *
377  *  When function tracing occurs, the following steps are made:
378  *   If arch does not support a ftrace feature:
379  *    call internal function (uses INTERNAL bits) which calls...
380  *   If callback is registered to the "global" list, the list
381  *    function is called and recursion checks the GLOBAL bits.
382  *    then this function calls...
383  *   The function callback, which can use the FTRACE bits to
384  *    check for recursion.
385  *
386  * Now if the arch does not suppport a feature, and it calls
387  * the global list function which calls the ftrace callback
388  * all three of these steps will do a recursion protection.
389  * There's no reason to do one if the previous caller already
390  * did. The recursion that we are protecting against will
391  * go through the same steps again.
392  *
393  * To prevent the multiple recursion checks, if a recursion
394  * bit is set that is higher than the MAX bit of the current
395  * check, then we know that the check was made by the previous
396  * caller, and we can skip the current check.
397  */
398 enum {
399 	TRACE_BUFFER_BIT,
400 	TRACE_BUFFER_NMI_BIT,
401 	TRACE_BUFFER_IRQ_BIT,
402 	TRACE_BUFFER_SIRQ_BIT,
403 
404 	/* Start of function recursion bits */
405 	TRACE_FTRACE_BIT,
406 	TRACE_FTRACE_NMI_BIT,
407 	TRACE_FTRACE_IRQ_BIT,
408 	TRACE_FTRACE_SIRQ_BIT,
409 
410 	/* GLOBAL_BITs must be greater than FTRACE_BITs */
411 	TRACE_GLOBAL_BIT,
412 	TRACE_GLOBAL_NMI_BIT,
413 	TRACE_GLOBAL_IRQ_BIT,
414 	TRACE_GLOBAL_SIRQ_BIT,
415 
416 	/* INTERNAL_BITs must be greater than GLOBAL_BITs */
417 	TRACE_INTERNAL_BIT,
418 	TRACE_INTERNAL_NMI_BIT,
419 	TRACE_INTERNAL_IRQ_BIT,
420 	TRACE_INTERNAL_SIRQ_BIT,
421 
422 	TRACE_CONTROL_BIT,
423 
424 /*
425  * Abuse of the trace_recursion.
426  * As we need a way to maintain state if we are tracing the function
427  * graph in irq because we want to trace a particular function that
428  * was called in irq context but we have irq tracing off. Since this
429  * can only be modified by current, we can reuse trace_recursion.
430  */
431 	TRACE_IRQ_BIT,
432 };
433 
434 #define trace_recursion_set(bit)	do { (current)->trace_recursion |= (1<<(bit)); } while (0)
435 #define trace_recursion_clear(bit)	do { (current)->trace_recursion &= ~(1<<(bit)); } while (0)
436 #define trace_recursion_test(bit)	((current)->trace_recursion & (1<<(bit)))
437 
438 #define TRACE_CONTEXT_BITS	4
439 
440 #define TRACE_FTRACE_START	TRACE_FTRACE_BIT
441 #define TRACE_FTRACE_MAX	((1 << (TRACE_FTRACE_START + TRACE_CONTEXT_BITS)) - 1)
442 
443 #define TRACE_GLOBAL_START	TRACE_GLOBAL_BIT
444 #define TRACE_GLOBAL_MAX	((1 << (TRACE_GLOBAL_START + TRACE_CONTEXT_BITS)) - 1)
445 
446 #define TRACE_LIST_START	TRACE_INTERNAL_BIT
447 #define TRACE_LIST_MAX		((1 << (TRACE_LIST_START + TRACE_CONTEXT_BITS)) - 1)
448 
449 #define TRACE_CONTEXT_MASK	TRACE_LIST_MAX
450 
451 static __always_inline int trace_get_context_bit(void)
452 {
453 	int bit;
454 
455 	if (in_interrupt()) {
456 		if (in_nmi())
457 			bit = 0;
458 
459 		else if (in_irq())
460 			bit = 1;
461 		else
462 			bit = 2;
463 	} else
464 		bit = 3;
465 
466 	return bit;
467 }
468 
469 static __always_inline int trace_test_and_set_recursion(int start, int max)
470 {
471 	unsigned int val = current->trace_recursion;
472 	int bit;
473 
474 	/* A previous recursion check was made */
475 	if ((val & TRACE_CONTEXT_MASK) > max)
476 		return 0;
477 
478 	bit = trace_get_context_bit() + start;
479 	if (unlikely(val & (1 << bit)))
480 		return -1;
481 
482 	val |= 1 << bit;
483 	current->trace_recursion = val;
484 	barrier();
485 
486 	return bit;
487 }
488 
489 static __always_inline void trace_clear_recursion(int bit)
490 {
491 	unsigned int val = current->trace_recursion;
492 
493 	if (!bit)
494 		return;
495 
496 	bit = 1 << bit;
497 	val &= ~bit;
498 
499 	barrier();
500 	current->trace_recursion = val;
501 }
502 
503 static inline struct ring_buffer_iter *
504 trace_buffer_iter(struct trace_iterator *iter, int cpu)
505 {
506 	if (iter->buffer_iter && iter->buffer_iter[cpu])
507 		return iter->buffer_iter[cpu];
508 	return NULL;
509 }
510 
511 int tracer_init(struct tracer *t, struct trace_array *tr);
512 int tracing_is_enabled(void);
513 void tracing_reset(struct trace_buffer *buf, int cpu);
514 void tracing_reset_online_cpus(struct trace_buffer *buf);
515 void tracing_reset_current(int cpu);
516 void tracing_reset_all_online_cpus(void);
517 int tracing_open_generic(struct inode *inode, struct file *filp);
518 struct dentry *trace_create_file(const char *name,
519 				 umode_t mode,
520 				 struct dentry *parent,
521 				 void *data,
522 				 const struct file_operations *fops);
523 
524 struct dentry *tracing_init_dentry_tr(struct trace_array *tr);
525 struct dentry *tracing_init_dentry(void);
526 
527 struct ring_buffer_event;
528 
529 struct ring_buffer_event *
530 trace_buffer_lock_reserve(struct ring_buffer *buffer,
531 			  int type,
532 			  unsigned long len,
533 			  unsigned long flags,
534 			  int pc);
535 
536 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
537 						struct trace_array_cpu *data);
538 
539 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
540 					  int *ent_cpu, u64 *ent_ts);
541 
542 void __buffer_unlock_commit(struct ring_buffer *buffer,
543 			    struct ring_buffer_event *event);
544 
545 int trace_empty(struct trace_iterator *iter);
546 
547 void *trace_find_next_entry_inc(struct trace_iterator *iter);
548 
549 void trace_init_global_iter(struct trace_iterator *iter);
550 
551 void tracing_iter_reset(struct trace_iterator *iter, int cpu);
552 
553 void poll_wait_pipe(struct trace_iterator *iter);
554 
555 void tracing_sched_switch_trace(struct trace_array *tr,
556 				struct task_struct *prev,
557 				struct task_struct *next,
558 				unsigned long flags, int pc);
559 
560 void tracing_sched_wakeup_trace(struct trace_array *tr,
561 				struct task_struct *wakee,
562 				struct task_struct *cur,
563 				unsigned long flags, int pc);
564 void trace_function(struct trace_array *tr,
565 		    unsigned long ip,
566 		    unsigned long parent_ip,
567 		    unsigned long flags, int pc);
568 void trace_graph_function(struct trace_array *tr,
569 		    unsigned long ip,
570 		    unsigned long parent_ip,
571 		    unsigned long flags, int pc);
572 void trace_latency_header(struct seq_file *m);
573 void trace_default_header(struct seq_file *m);
574 void print_trace_header(struct seq_file *m, struct trace_iterator *iter);
575 int trace_empty(struct trace_iterator *iter);
576 
577 void trace_graph_return(struct ftrace_graph_ret *trace);
578 int trace_graph_entry(struct ftrace_graph_ent *trace);
579 void set_graph_array(struct trace_array *tr);
580 
581 void tracing_start_cmdline_record(void);
582 void tracing_stop_cmdline_record(void);
583 void tracing_sched_switch_assign_trace(struct trace_array *tr);
584 void tracing_stop_sched_switch_record(void);
585 void tracing_start_sched_switch_record(void);
586 int register_tracer(struct tracer *type);
587 int is_tracing_stopped(void);
588 
589 extern cpumask_var_t __read_mostly tracing_buffer_mask;
590 
591 #define for_each_tracing_cpu(cpu)	\
592 	for_each_cpu(cpu, tracing_buffer_mask)
593 
594 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
595 
596 extern unsigned long tracing_thresh;
597 
598 #ifdef CONFIG_TRACER_MAX_TRACE
599 extern unsigned long tracing_max_latency;
600 
601 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
602 void update_max_tr_single(struct trace_array *tr,
603 			  struct task_struct *tsk, int cpu);
604 #endif /* CONFIG_TRACER_MAX_TRACE */
605 
606 #ifdef CONFIG_STACKTRACE
607 void ftrace_trace_stack(struct ring_buffer *buffer, unsigned long flags,
608 			int skip, int pc);
609 
610 void ftrace_trace_stack_regs(struct ring_buffer *buffer, unsigned long flags,
611 			     int skip, int pc, struct pt_regs *regs);
612 
613 void ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags,
614 			    int pc);
615 
616 void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
617 		   int pc);
618 #else
619 static inline void ftrace_trace_stack(struct ring_buffer *buffer,
620 				      unsigned long flags, int skip, int pc)
621 {
622 }
623 
624 static inline void ftrace_trace_stack_regs(struct ring_buffer *buffer,
625 					   unsigned long flags, int skip,
626 					   int pc, struct pt_regs *regs)
627 {
628 }
629 
630 static inline void ftrace_trace_userstack(struct ring_buffer *buffer,
631 					  unsigned long flags, int pc)
632 {
633 }
634 
635 static inline void __trace_stack(struct trace_array *tr, unsigned long flags,
636 				 int skip, int pc)
637 {
638 }
639 #endif /* CONFIG_STACKTRACE */
640 
641 extern cycle_t ftrace_now(int cpu);
642 
643 extern void trace_find_cmdline(int pid, char comm[]);
644 
645 #ifdef CONFIG_DYNAMIC_FTRACE
646 extern unsigned long ftrace_update_tot_cnt;
647 #endif
648 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
649 extern int DYN_FTRACE_TEST_NAME(void);
650 #define DYN_FTRACE_TEST_NAME2 trace_selftest_dynamic_test_func2
651 extern int DYN_FTRACE_TEST_NAME2(void);
652 
653 extern bool ring_buffer_expanded;
654 extern bool tracing_selftest_disabled;
655 DECLARE_PER_CPU(int, ftrace_cpu_disabled);
656 
657 #ifdef CONFIG_FTRACE_STARTUP_TEST
658 extern int trace_selftest_startup_function(struct tracer *trace,
659 					   struct trace_array *tr);
660 extern int trace_selftest_startup_function_graph(struct tracer *trace,
661 						 struct trace_array *tr);
662 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
663 					  struct trace_array *tr);
664 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
665 					     struct trace_array *tr);
666 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
667 						 struct trace_array *tr);
668 extern int trace_selftest_startup_wakeup(struct tracer *trace,
669 					 struct trace_array *tr);
670 extern int trace_selftest_startup_nop(struct tracer *trace,
671 					 struct trace_array *tr);
672 extern int trace_selftest_startup_sched_switch(struct tracer *trace,
673 					       struct trace_array *tr);
674 extern int trace_selftest_startup_branch(struct tracer *trace,
675 					 struct trace_array *tr);
676 /*
677  * Tracer data references selftest functions that only occur
678  * on boot up. These can be __init functions. Thus, when selftests
679  * are enabled, then the tracers need to reference __init functions.
680  */
681 #define __tracer_data		__refdata
682 #else
683 /* Tracers are seldom changed. Optimize when selftests are disabled. */
684 #define __tracer_data		__read_mostly
685 #endif /* CONFIG_FTRACE_STARTUP_TEST */
686 
687 extern void *head_page(struct trace_array_cpu *data);
688 extern unsigned long long ns2usecs(cycle_t nsec);
689 extern int
690 trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
691 extern int
692 trace_vprintk(unsigned long ip, const char *fmt, va_list args);
693 extern int
694 trace_array_vprintk(struct trace_array *tr,
695 		    unsigned long ip, const char *fmt, va_list args);
696 int trace_array_printk(struct trace_array *tr,
697 		       unsigned long ip, const char *fmt, ...);
698 int trace_array_printk_buf(struct ring_buffer *buffer,
699 			   unsigned long ip, const char *fmt, ...);
700 void trace_printk_seq(struct trace_seq *s);
701 enum print_line_t print_trace_line(struct trace_iterator *iter);
702 
703 extern unsigned long trace_flags;
704 
705 /* Standard output formatting function used for function return traces */
706 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
707 
708 /* Flag options */
709 #define TRACE_GRAPH_PRINT_OVERRUN       0x1
710 #define TRACE_GRAPH_PRINT_CPU           0x2
711 #define TRACE_GRAPH_PRINT_OVERHEAD      0x4
712 #define TRACE_GRAPH_PRINT_PROC          0x8
713 #define TRACE_GRAPH_PRINT_DURATION      0x10
714 #define TRACE_GRAPH_PRINT_ABS_TIME      0x20
715 
716 extern enum print_line_t
717 print_graph_function_flags(struct trace_iterator *iter, u32 flags);
718 extern void print_graph_headers_flags(struct seq_file *s, u32 flags);
719 extern enum print_line_t
720 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
721 extern void graph_trace_open(struct trace_iterator *iter);
722 extern void graph_trace_close(struct trace_iterator *iter);
723 extern int __trace_graph_entry(struct trace_array *tr,
724 			       struct ftrace_graph_ent *trace,
725 			       unsigned long flags, int pc);
726 extern void __trace_graph_return(struct trace_array *tr,
727 				 struct ftrace_graph_ret *trace,
728 				 unsigned long flags, int pc);
729 
730 
731 #ifdef CONFIG_DYNAMIC_FTRACE
732 /* TODO: make this variable */
733 #define FTRACE_GRAPH_MAX_FUNCS		32
734 extern int ftrace_graph_filter_enabled;
735 extern int ftrace_graph_count;
736 extern unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS];
737 
738 static inline int ftrace_graph_addr(unsigned long addr)
739 {
740 	int i;
741 
742 	if (!ftrace_graph_filter_enabled)
743 		return 1;
744 
745 	for (i = 0; i < ftrace_graph_count; i++) {
746 		if (addr == ftrace_graph_funcs[i]) {
747 			/*
748 			 * If no irqs are to be traced, but a set_graph_function
749 			 * is set, and called by an interrupt handler, we still
750 			 * want to trace it.
751 			 */
752 			if (in_irq())
753 				trace_recursion_set(TRACE_IRQ_BIT);
754 			else
755 				trace_recursion_clear(TRACE_IRQ_BIT);
756 			return 1;
757 		}
758 	}
759 
760 	return 0;
761 }
762 #else
763 static inline int ftrace_graph_addr(unsigned long addr)
764 {
765 	return 1;
766 }
767 #endif /* CONFIG_DYNAMIC_FTRACE */
768 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
769 static inline enum print_line_t
770 print_graph_function_flags(struct trace_iterator *iter, u32 flags)
771 {
772 	return TRACE_TYPE_UNHANDLED;
773 }
774 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
775 
776 extern struct list_head ftrace_pids;
777 
778 #ifdef CONFIG_FUNCTION_TRACER
779 extern bool ftrace_filter_param __initdata;
780 static inline int ftrace_trace_task(struct task_struct *task)
781 {
782 	if (list_empty(&ftrace_pids))
783 		return 1;
784 
785 	return test_tsk_trace_trace(task);
786 }
787 extern int ftrace_is_dead(void);
788 #else
789 static inline int ftrace_trace_task(struct task_struct *task)
790 {
791 	return 1;
792 }
793 static inline int ftrace_is_dead(void) { return 0; }
794 #endif
795 
796 int ftrace_event_is_function(struct ftrace_event_call *call);
797 
798 /*
799  * struct trace_parser - servers for reading the user input separated by spaces
800  * @cont: set if the input is not complete - no final space char was found
801  * @buffer: holds the parsed user input
802  * @idx: user input length
803  * @size: buffer size
804  */
805 struct trace_parser {
806 	bool		cont;
807 	char		*buffer;
808 	unsigned	idx;
809 	unsigned	size;
810 };
811 
812 static inline bool trace_parser_loaded(struct trace_parser *parser)
813 {
814 	return (parser->idx != 0);
815 }
816 
817 static inline bool trace_parser_cont(struct trace_parser *parser)
818 {
819 	return parser->cont;
820 }
821 
822 static inline void trace_parser_clear(struct trace_parser *parser)
823 {
824 	parser->cont = false;
825 	parser->idx = 0;
826 }
827 
828 extern int trace_parser_get_init(struct trace_parser *parser, int size);
829 extern void trace_parser_put(struct trace_parser *parser);
830 extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
831 	size_t cnt, loff_t *ppos);
832 
833 /*
834  * trace_iterator_flags is an enumeration that defines bit
835  * positions into trace_flags that controls the output.
836  *
837  * NOTE: These bits must match the trace_options array in
838  *       trace.c.
839  */
840 enum trace_iterator_flags {
841 	TRACE_ITER_PRINT_PARENT		= 0x01,
842 	TRACE_ITER_SYM_OFFSET		= 0x02,
843 	TRACE_ITER_SYM_ADDR		= 0x04,
844 	TRACE_ITER_VERBOSE		= 0x08,
845 	TRACE_ITER_RAW			= 0x10,
846 	TRACE_ITER_HEX			= 0x20,
847 	TRACE_ITER_BIN			= 0x40,
848 	TRACE_ITER_BLOCK		= 0x80,
849 	TRACE_ITER_STACKTRACE		= 0x100,
850 	TRACE_ITER_PRINTK		= 0x200,
851 	TRACE_ITER_PREEMPTONLY		= 0x400,
852 	TRACE_ITER_BRANCH		= 0x800,
853 	TRACE_ITER_ANNOTATE		= 0x1000,
854 	TRACE_ITER_USERSTACKTRACE       = 0x2000,
855 	TRACE_ITER_SYM_USEROBJ          = 0x4000,
856 	TRACE_ITER_PRINTK_MSGONLY	= 0x8000,
857 	TRACE_ITER_CONTEXT_INFO		= 0x10000, /* Print pid/cpu/time */
858 	TRACE_ITER_LATENCY_FMT		= 0x20000,
859 	TRACE_ITER_SLEEP_TIME		= 0x40000,
860 	TRACE_ITER_GRAPH_TIME		= 0x80000,
861 	TRACE_ITER_RECORD_CMD		= 0x100000,
862 	TRACE_ITER_OVERWRITE		= 0x200000,
863 	TRACE_ITER_STOP_ON_FREE		= 0x400000,
864 	TRACE_ITER_IRQ_INFO		= 0x800000,
865 	TRACE_ITER_MARKERS		= 0x1000000,
866 	TRACE_ITER_FUNCTION		= 0x2000000,
867 };
868 
869 /*
870  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
871  * control the output of kernel symbols.
872  */
873 #define TRACE_ITER_SYM_MASK \
874 	(TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
875 
876 extern struct tracer nop_trace;
877 
878 #ifdef CONFIG_BRANCH_TRACER
879 extern int enable_branch_tracing(struct trace_array *tr);
880 extern void disable_branch_tracing(void);
881 static inline int trace_branch_enable(struct trace_array *tr)
882 {
883 	if (trace_flags & TRACE_ITER_BRANCH)
884 		return enable_branch_tracing(tr);
885 	return 0;
886 }
887 static inline void trace_branch_disable(void)
888 {
889 	/* due to races, always disable */
890 	disable_branch_tracing();
891 }
892 #else
893 static inline int trace_branch_enable(struct trace_array *tr)
894 {
895 	return 0;
896 }
897 static inline void trace_branch_disable(void)
898 {
899 }
900 #endif /* CONFIG_BRANCH_TRACER */
901 
902 /* set ring buffers to default size if not already done so */
903 int tracing_update_buffers(void);
904 
905 struct ftrace_event_field {
906 	struct list_head	link;
907 	const char		*name;
908 	const char		*type;
909 	int			filter_type;
910 	int			offset;
911 	int			size;
912 	int			is_signed;
913 };
914 
915 struct event_filter {
916 	int			n_preds;	/* Number assigned */
917 	int			a_preds;	/* allocated */
918 	struct filter_pred	*preds;
919 	struct filter_pred	*root;
920 	char			*filter_string;
921 };
922 
923 struct event_subsystem {
924 	struct list_head	list;
925 	const char		*name;
926 	struct event_filter	*filter;
927 	int			ref_count;
928 };
929 
930 struct ftrace_subsystem_dir {
931 	struct list_head		list;
932 	struct event_subsystem		*subsystem;
933 	struct trace_array		*tr;
934 	struct dentry			*entry;
935 	int				ref_count;
936 	int				nr_events;
937 };
938 
939 #define FILTER_PRED_INVALID	((unsigned short)-1)
940 #define FILTER_PRED_IS_RIGHT	(1 << 15)
941 #define FILTER_PRED_FOLD	(1 << 15)
942 
943 /*
944  * The max preds is the size of unsigned short with
945  * two flags at the MSBs. One bit is used for both the IS_RIGHT
946  * and FOLD flags. The other is reserved.
947  *
948  * 2^14 preds is way more than enough.
949  */
950 #define MAX_FILTER_PRED		16384
951 
952 struct filter_pred;
953 struct regex;
954 
955 typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event);
956 
957 typedef int (*regex_match_func)(char *str, struct regex *r, int len);
958 
959 enum regex_type {
960 	MATCH_FULL = 0,
961 	MATCH_FRONT_ONLY,
962 	MATCH_MIDDLE_ONLY,
963 	MATCH_END_ONLY,
964 };
965 
966 struct regex {
967 	char			pattern[MAX_FILTER_STR_VAL];
968 	int			len;
969 	int			field_len;
970 	regex_match_func	match;
971 };
972 
973 struct filter_pred {
974 	filter_pred_fn_t 	fn;
975 	u64 			val;
976 	struct regex		regex;
977 	unsigned short		*ops;
978 	struct ftrace_event_field *field;
979 	int 			offset;
980 	int 			not;
981 	int 			op;
982 	unsigned short		index;
983 	unsigned short		parent;
984 	unsigned short		left;
985 	unsigned short		right;
986 };
987 
988 extern enum regex_type
989 filter_parse_regex(char *buff, int len, char **search, int *not);
990 extern void print_event_filter(struct ftrace_event_call *call,
991 			       struct trace_seq *s);
992 extern int apply_event_filter(struct ftrace_event_call *call,
993 			      char *filter_string);
994 extern int apply_subsystem_event_filter(struct ftrace_subsystem_dir *dir,
995 					char *filter_string);
996 extern void print_subsystem_event_filter(struct event_subsystem *system,
997 					 struct trace_seq *s);
998 extern int filter_assign_type(const char *type);
999 
1000 struct ftrace_event_field *
1001 trace_find_event_field(struct ftrace_event_call *call, char *name);
1002 
1003 static inline int
1004 filter_check_discard(struct ftrace_event_call *call, void *rec,
1005 		     struct ring_buffer *buffer,
1006 		     struct ring_buffer_event *event)
1007 {
1008 	if (unlikely(call->flags & TRACE_EVENT_FL_FILTERED) &&
1009 	    !filter_match_preds(call->filter, rec)) {
1010 		ring_buffer_discard_commit(buffer, event);
1011 		return 1;
1012 	}
1013 
1014 	return 0;
1015 }
1016 
1017 extern void trace_event_enable_cmd_record(bool enable);
1018 extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
1019 extern int event_trace_del_tracer(struct trace_array *tr);
1020 
1021 extern struct mutex event_mutex;
1022 extern struct list_head ftrace_events;
1023 
1024 extern const char *__start___trace_bprintk_fmt[];
1025 extern const char *__stop___trace_bprintk_fmt[];
1026 
1027 extern const char *__start___tracepoint_str[];
1028 extern const char *__stop___tracepoint_str[];
1029 
1030 void trace_printk_init_buffers(void);
1031 void trace_printk_start_comm(void);
1032 int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set);
1033 int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled);
1034 
1035 /*
1036  * Normal trace_printk() and friends allocates special buffers
1037  * to do the manipulation, as well as saves the print formats
1038  * into sections to display. But the trace infrastructure wants
1039  * to use these without the added overhead at the price of being
1040  * a bit slower (used mainly for warnings, where we don't care
1041  * about performance). The internal_trace_puts() is for such
1042  * a purpose.
1043  */
1044 #define internal_trace_puts(str) __trace_puts(_THIS_IP_, str, strlen(str))
1045 
1046 #undef FTRACE_ENTRY
1047 #define FTRACE_ENTRY(call, struct_name, id, tstruct, print, filter)	\
1048 	extern struct ftrace_event_call					\
1049 	__attribute__((__aligned__(4))) event_##call;
1050 #undef FTRACE_ENTRY_DUP
1051 #define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print, filter)	\
1052 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print), \
1053 		     filter)
1054 #include "trace_entries.h"
1055 
1056 #if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_FUNCTION_TRACER)
1057 int perf_ftrace_event_register(struct ftrace_event_call *call,
1058 			       enum trace_reg type, void *data);
1059 #else
1060 #define perf_ftrace_event_register NULL
1061 #endif
1062 
1063 #endif /* _LINUX_KERNEL_TRACE_H */
1064