xref: /linux/kernel/trace/trace.h (revision c75c5ab575af7db707689cdbb5a5c458e9a034bb)
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 enum trace_type {
17 	__TRACE_FIRST_TYPE = 0,
18 
19 	TRACE_FN,
20 	TRACE_CTX,
21 	TRACE_WAKE,
22 	TRACE_STACK,
23 	TRACE_PRINT,
24 	TRACE_BPRINT,
25 	TRACE_MMIO_RW,
26 	TRACE_MMIO_MAP,
27 	TRACE_BRANCH,
28 	TRACE_GRAPH_RET,
29 	TRACE_GRAPH_ENT,
30 	TRACE_USER_STACK,
31 	TRACE_BLK,
32 
33 	__TRACE_LAST_TYPE,
34 };
35 
36 
37 #undef __field
38 #define __field(type, item)		type	item;
39 
40 #undef __field_struct
41 #define __field_struct(type, item)	__field(type, item)
42 
43 #undef __field_desc
44 #define __field_desc(type, container, item)
45 
46 #undef __array
47 #define __array(type, item, size)	type	item[size];
48 
49 #undef __array_desc
50 #define __array_desc(type, container, item, size)
51 
52 #undef __dynamic_array
53 #define __dynamic_array(type, item)	type	item[];
54 
55 #undef F_STRUCT
56 #define F_STRUCT(args...)		args
57 
58 #undef FTRACE_ENTRY
59 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print, filter)	\
60 	struct struct_name {						\
61 		struct trace_entry	ent;				\
62 		tstruct							\
63 	}
64 
65 #undef TP_ARGS
66 #define TP_ARGS(args...)	args
67 
68 #undef FTRACE_ENTRY_DUP
69 #define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk, filter)
70 
71 #undef FTRACE_ENTRY_REG
72 #define FTRACE_ENTRY_REG(name, struct_name, id, tstruct, print,	\
73 			 filter, regfn) \
74 	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print), \
75 		     filter)
76 
77 #include "trace_entries.h"
78 
79 /*
80  * syscalls are special, and need special handling, this is why
81  * they are not included in trace_entries.h
82  */
83 struct syscall_trace_enter {
84 	struct trace_entry	ent;
85 	int			nr;
86 	unsigned long		args[];
87 };
88 
89 struct syscall_trace_exit {
90 	struct trace_entry	ent;
91 	int			nr;
92 	long			ret;
93 };
94 
95 struct kprobe_trace_entry_head {
96 	struct trace_entry	ent;
97 	unsigned long		ip;
98 };
99 
100 struct kretprobe_trace_entry_head {
101 	struct trace_entry	ent;
102 	unsigned long		func;
103 	unsigned long		ret_ip;
104 };
105 
106 struct uprobe_trace_entry_head {
107 	struct trace_entry	ent;
108 	unsigned long		ip;
109 };
110 
111 /*
112  * trace_flag_type is an enumeration that holds different
113  * states when a trace occurs. These are:
114  *  IRQS_OFF		- interrupts were disabled
115  *  IRQS_NOSUPPORT	- arch does not support irqs_disabled_flags
116  *  NEED_RESCHED	- reschedule is requested
117  *  HARDIRQ		- inside an interrupt handler
118  *  SOFTIRQ		- inside a softirq handler
119  */
120 enum trace_flag_type {
121 	TRACE_FLAG_IRQS_OFF		= 0x01,
122 	TRACE_FLAG_IRQS_NOSUPPORT	= 0x02,
123 	TRACE_FLAG_NEED_RESCHED		= 0x04,
124 	TRACE_FLAG_HARDIRQ		= 0x08,
125 	TRACE_FLAG_SOFTIRQ		= 0x10,
126 };
127 
128 #define TRACE_BUF_SIZE		1024
129 
130 /*
131  * The CPU trace array - it consists of thousands of trace entries
132  * plus some other descriptor data: (for example which task started
133  * the trace, etc.)
134  */
135 struct trace_array_cpu {
136 	atomic_t		disabled;
137 	void			*buffer_page;	/* ring buffer spare */
138 
139 	unsigned long		entries;
140 	unsigned long		saved_latency;
141 	unsigned long		critical_start;
142 	unsigned long		critical_end;
143 	unsigned long		critical_sequence;
144 	unsigned long		nice;
145 	unsigned long		policy;
146 	unsigned long		rt_priority;
147 	unsigned long		skipped_entries;
148 	cycle_t			preempt_timestamp;
149 	pid_t			pid;
150 	kuid_t			uid;
151 	char			comm[TASK_COMM_LEN];
152 };
153 
154 /*
155  * The trace array - an array of per-CPU trace arrays. This is the
156  * highest level data structure that individual tracers deal with.
157  * They have on/off state as well:
158  */
159 struct trace_array {
160 	struct ring_buffer	*buffer;
161 	int			cpu;
162 	int			buffer_disabled;
163 	cycle_t			time_start;
164 	struct task_struct	*waiter;
165 	struct trace_array_cpu	*data[NR_CPUS];
166 };
167 
168 #define FTRACE_CMP_TYPE(var, type) \
169 	__builtin_types_compatible_p(typeof(var), type *)
170 
171 #undef IF_ASSIGN
172 #define IF_ASSIGN(var, entry, etype, id)		\
173 	if (FTRACE_CMP_TYPE(var, etype)) {		\
174 		var = (typeof(var))(entry);		\
175 		WARN_ON(id && (entry)->type != id);	\
176 		break;					\
177 	}
178 
179 /* Will cause compile errors if type is not found. */
180 extern void __ftrace_bad_type(void);
181 
182 /*
183  * The trace_assign_type is a verifier that the entry type is
184  * the same as the type being assigned. To add new types simply
185  * add a line with the following format:
186  *
187  * IF_ASSIGN(var, ent, type, id);
188  *
189  *  Where "type" is the trace type that includes the trace_entry
190  *  as the "ent" item. And "id" is the trace identifier that is
191  *  used in the trace_type enum.
192  *
193  *  If the type can have more than one id, then use zero.
194  */
195 #define trace_assign_type(var, ent)					\
196 	do {								\
197 		IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);	\
198 		IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);	\
199 		IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);	\
200 		IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
201 		IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);	\
202 		IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT);	\
203 		IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,		\
204 			  TRACE_MMIO_RW);				\
205 		IF_ASSIGN(var, ent, struct trace_mmiotrace_map,		\
206 			  TRACE_MMIO_MAP);				\
207 		IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
208 		IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,	\
209 			  TRACE_GRAPH_ENT);		\
210 		IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,	\
211 			  TRACE_GRAPH_RET);		\
212 		__ftrace_bad_type();					\
213 	} while (0)
214 
215 /*
216  * An option specific to a tracer. This is a boolean value.
217  * The bit is the bit index that sets its value on the
218  * flags value in struct tracer_flags.
219  */
220 struct tracer_opt {
221 	const char	*name; /* Will appear on the trace_options file */
222 	u32		bit; /* Mask assigned in val field in tracer_flags */
223 };
224 
225 /*
226  * The set of specific options for a tracer. Your tracer
227  * have to set the initial value of the flags val.
228  */
229 struct tracer_flags {
230 	u32			val;
231 	struct tracer_opt	*opts;
232 };
233 
234 /* Makes more easy to define a tracer opt */
235 #define TRACER_OPT(s, b)	.name = #s, .bit = b
236 
237 
238 /**
239  * struct tracer - a specific tracer and its callbacks to interact with debugfs
240  * @name: the name chosen to select it on the available_tracers file
241  * @init: called when one switches to this tracer (echo name > current_tracer)
242  * @reset: called when one switches to another tracer
243  * @start: called when tracing is unpaused (echo 1 > tracing_enabled)
244  * @stop: called when tracing is paused (echo 0 > tracing_enabled)
245  * @open: called when the trace file is opened
246  * @pipe_open: called when the trace_pipe file is opened
247  * @wait_pipe: override how the user waits for traces on trace_pipe
248  * @close: called when the trace file is released
249  * @pipe_close: called when the trace_pipe file is released
250  * @read: override the default read callback on trace_pipe
251  * @splice_read: override the default splice_read callback on trace_pipe
252  * @selftest: selftest to run on boot (see trace_selftest.c)
253  * @print_headers: override the first lines that describe your columns
254  * @print_line: callback that prints a trace
255  * @set_flag: signals one of your private flags changed (trace_options file)
256  * @flags: your private flags
257  */
258 struct tracer {
259 	const char		*name;
260 	int			(*init)(struct trace_array *tr);
261 	void			(*reset)(struct trace_array *tr);
262 	void			(*start)(struct trace_array *tr);
263 	void			(*stop)(struct trace_array *tr);
264 	void			(*open)(struct trace_iterator *iter);
265 	void			(*pipe_open)(struct trace_iterator *iter);
266 	void			(*wait_pipe)(struct trace_iterator *iter);
267 	void			(*close)(struct trace_iterator *iter);
268 	void			(*pipe_close)(struct trace_iterator *iter);
269 	ssize_t			(*read)(struct trace_iterator *iter,
270 					struct file *filp, char __user *ubuf,
271 					size_t cnt, loff_t *ppos);
272 	ssize_t			(*splice_read)(struct trace_iterator *iter,
273 					       struct file *filp,
274 					       loff_t *ppos,
275 					       struct pipe_inode_info *pipe,
276 					       size_t len,
277 					       unsigned int flags);
278 #ifdef CONFIG_FTRACE_STARTUP_TEST
279 	int			(*selftest)(struct tracer *trace,
280 					    struct trace_array *tr);
281 #endif
282 	void			(*print_header)(struct seq_file *m);
283 	enum print_line_t	(*print_line)(struct trace_iterator *iter);
284 	/* If you handled the flag setting, return 0 */
285 	int			(*set_flag)(u32 old_flags, u32 bit, int set);
286 	/* Return 0 if OK with change, else return non-zero */
287 	int			(*flag_changed)(struct tracer *tracer,
288 						u32 mask, int set);
289 	struct tracer		*next;
290 	struct tracer_flags	*flags;
291 	bool			print_max;
292 	bool			use_max_tr;
293 	bool			allocated_snapshot;
294 	bool			enabled;
295 };
296 
297 
298 /* Only current can touch trace_recursion */
299 
300 /*
301  * For function tracing recursion:
302  *  The order of these bits are important.
303  *
304  *  When function tracing occurs, the following steps are made:
305  *   If arch does not support a ftrace feature:
306  *    call internal function (uses INTERNAL bits) which calls...
307  *   If callback is registered to the "global" list, the list
308  *    function is called and recursion checks the GLOBAL bits.
309  *    then this function calls...
310  *   The function callback, which can use the FTRACE bits to
311  *    check for recursion.
312  *
313  * Now if the arch does not suppport a feature, and it calls
314  * the global list function which calls the ftrace callback
315  * all three of these steps will do a recursion protection.
316  * There's no reason to do one if the previous caller already
317  * did. The recursion that we are protecting against will
318  * go through the same steps again.
319  *
320  * To prevent the multiple recursion checks, if a recursion
321  * bit is set that is higher than the MAX bit of the current
322  * check, then we know that the check was made by the previous
323  * caller, and we can skip the current check.
324  */
325 enum {
326 	TRACE_BUFFER_BIT,
327 	TRACE_BUFFER_NMI_BIT,
328 	TRACE_BUFFER_IRQ_BIT,
329 	TRACE_BUFFER_SIRQ_BIT,
330 
331 	/* Start of function recursion bits */
332 	TRACE_FTRACE_BIT,
333 	TRACE_FTRACE_NMI_BIT,
334 	TRACE_FTRACE_IRQ_BIT,
335 	TRACE_FTRACE_SIRQ_BIT,
336 
337 	/* GLOBAL_BITs must be greater than FTRACE_BITs */
338 	TRACE_GLOBAL_BIT,
339 	TRACE_GLOBAL_NMI_BIT,
340 	TRACE_GLOBAL_IRQ_BIT,
341 	TRACE_GLOBAL_SIRQ_BIT,
342 
343 	/* INTERNAL_BITs must be greater than GLOBAL_BITs */
344 	TRACE_INTERNAL_BIT,
345 	TRACE_INTERNAL_NMI_BIT,
346 	TRACE_INTERNAL_IRQ_BIT,
347 	TRACE_INTERNAL_SIRQ_BIT,
348 
349 	TRACE_CONTROL_BIT,
350 
351 /*
352  * Abuse of the trace_recursion.
353  * As we need a way to maintain state if we are tracing the function
354  * graph in irq because we want to trace a particular function that
355  * was called in irq context but we have irq tracing off. Since this
356  * can only be modified by current, we can reuse trace_recursion.
357  */
358 	TRACE_IRQ_BIT,
359 };
360 
361 #define trace_recursion_set(bit)	do { (current)->trace_recursion |= (1<<(bit)); } while (0)
362 #define trace_recursion_clear(bit)	do { (current)->trace_recursion &= ~(1<<(bit)); } while (0)
363 #define trace_recursion_test(bit)	((current)->trace_recursion & (1<<(bit)))
364 
365 #define TRACE_CONTEXT_BITS	4
366 
367 #define TRACE_FTRACE_START	TRACE_FTRACE_BIT
368 #define TRACE_FTRACE_MAX	((1 << (TRACE_FTRACE_START + TRACE_CONTEXT_BITS)) - 1)
369 
370 #define TRACE_GLOBAL_START	TRACE_GLOBAL_BIT
371 #define TRACE_GLOBAL_MAX	((1 << (TRACE_GLOBAL_START + TRACE_CONTEXT_BITS)) - 1)
372 
373 #define TRACE_LIST_START	TRACE_INTERNAL_BIT
374 #define TRACE_LIST_MAX		((1 << (TRACE_LIST_START + TRACE_CONTEXT_BITS)) - 1)
375 
376 #define TRACE_CONTEXT_MASK	TRACE_LIST_MAX
377 
378 static __always_inline int trace_get_context_bit(void)
379 {
380 	int bit;
381 
382 	if (in_interrupt()) {
383 		if (in_nmi())
384 			bit = 0;
385 
386 		else if (in_irq())
387 			bit = 1;
388 		else
389 			bit = 2;
390 	} else
391 		bit = 3;
392 
393 	return bit;
394 }
395 
396 static __always_inline int trace_test_and_set_recursion(int start, int max)
397 {
398 	unsigned int val = current->trace_recursion;
399 	int bit;
400 
401 	/* A previous recursion check was made */
402 	if ((val & TRACE_CONTEXT_MASK) > max)
403 		return 0;
404 
405 	bit = trace_get_context_bit() + start;
406 	if (unlikely(val & (1 << bit)))
407 		return -1;
408 
409 	val |= 1 << bit;
410 	current->trace_recursion = val;
411 	barrier();
412 
413 	return bit;
414 }
415 
416 static __always_inline void trace_clear_recursion(int bit)
417 {
418 	unsigned int val = current->trace_recursion;
419 
420 	if (!bit)
421 		return;
422 
423 	bit = 1 << bit;
424 	val &= ~bit;
425 
426 	barrier();
427 	current->trace_recursion = val;
428 }
429 
430 #define TRACE_PIPE_ALL_CPU	-1
431 
432 static inline struct ring_buffer_iter *
433 trace_buffer_iter(struct trace_iterator *iter, int cpu)
434 {
435 	if (iter->buffer_iter && iter->buffer_iter[cpu])
436 		return iter->buffer_iter[cpu];
437 	return NULL;
438 }
439 
440 int tracer_init(struct tracer *t, struct trace_array *tr);
441 int tracing_is_enabled(void);
442 void tracing_reset(struct trace_array *tr, int cpu);
443 void tracing_reset_online_cpus(struct trace_array *tr);
444 void tracing_reset_current(int cpu);
445 void tracing_reset_current_online_cpus(void);
446 int tracing_open_generic(struct inode *inode, struct file *filp);
447 struct dentry *trace_create_file(const char *name,
448 				 umode_t mode,
449 				 struct dentry *parent,
450 				 void *data,
451 				 const struct file_operations *fops);
452 
453 struct dentry *tracing_init_dentry(void);
454 
455 struct ring_buffer_event;
456 
457 struct ring_buffer_event *
458 trace_buffer_lock_reserve(struct ring_buffer *buffer,
459 			  int type,
460 			  unsigned long len,
461 			  unsigned long flags,
462 			  int pc);
463 
464 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
465 						struct trace_array_cpu *data);
466 
467 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
468 					  int *ent_cpu, u64 *ent_ts);
469 
470 void __buffer_unlock_commit(struct ring_buffer *buffer,
471 			    struct ring_buffer_event *event);
472 
473 int trace_empty(struct trace_iterator *iter);
474 
475 void *trace_find_next_entry_inc(struct trace_iterator *iter);
476 
477 void trace_init_global_iter(struct trace_iterator *iter);
478 
479 void tracing_iter_reset(struct trace_iterator *iter, int cpu);
480 
481 void poll_wait_pipe(struct trace_iterator *iter);
482 
483 void ftrace(struct trace_array *tr,
484 			    struct trace_array_cpu *data,
485 			    unsigned long ip,
486 			    unsigned long parent_ip,
487 			    unsigned long flags, int pc);
488 void tracing_sched_switch_trace(struct trace_array *tr,
489 				struct task_struct *prev,
490 				struct task_struct *next,
491 				unsigned long flags, int pc);
492 
493 void tracing_sched_wakeup_trace(struct trace_array *tr,
494 				struct task_struct *wakee,
495 				struct task_struct *cur,
496 				unsigned long flags, int pc);
497 void trace_function(struct trace_array *tr,
498 		    unsigned long ip,
499 		    unsigned long parent_ip,
500 		    unsigned long flags, int pc);
501 void trace_graph_function(struct trace_array *tr,
502 		    unsigned long ip,
503 		    unsigned long parent_ip,
504 		    unsigned long flags, int pc);
505 void trace_latency_header(struct seq_file *m);
506 void trace_default_header(struct seq_file *m);
507 void print_trace_header(struct seq_file *m, struct trace_iterator *iter);
508 int trace_empty(struct trace_iterator *iter);
509 
510 void trace_graph_return(struct ftrace_graph_ret *trace);
511 int trace_graph_entry(struct ftrace_graph_ent *trace);
512 void set_graph_array(struct trace_array *tr);
513 
514 void tracing_start_cmdline_record(void);
515 void tracing_stop_cmdline_record(void);
516 void tracing_sched_switch_assign_trace(struct trace_array *tr);
517 void tracing_stop_sched_switch_record(void);
518 void tracing_start_sched_switch_record(void);
519 int register_tracer(struct tracer *type);
520 int is_tracing_stopped(void);
521 
522 extern cpumask_var_t __read_mostly tracing_buffer_mask;
523 
524 #define for_each_tracing_cpu(cpu)	\
525 	for_each_cpu(cpu, tracing_buffer_mask)
526 
527 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
528 
529 extern unsigned long tracing_thresh;
530 
531 #ifdef CONFIG_TRACER_MAX_TRACE
532 extern unsigned long tracing_max_latency;
533 
534 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
535 void update_max_tr_single(struct trace_array *tr,
536 			  struct task_struct *tsk, int cpu);
537 #endif /* CONFIG_TRACER_MAX_TRACE */
538 
539 #ifdef CONFIG_STACKTRACE
540 void ftrace_trace_stack(struct ring_buffer *buffer, unsigned long flags,
541 			int skip, int pc);
542 
543 void ftrace_trace_stack_regs(struct ring_buffer *buffer, unsigned long flags,
544 			     int skip, int pc, struct pt_regs *regs);
545 
546 void ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags,
547 			    int pc);
548 
549 void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
550 		   int pc);
551 #else
552 static inline void ftrace_trace_stack(struct ring_buffer *buffer,
553 				      unsigned long flags, int skip, int pc)
554 {
555 }
556 
557 static inline void ftrace_trace_stack_regs(struct ring_buffer *buffer,
558 					   unsigned long flags, int skip,
559 					   int pc, struct pt_regs *regs)
560 {
561 }
562 
563 static inline void ftrace_trace_userstack(struct ring_buffer *buffer,
564 					  unsigned long flags, int pc)
565 {
566 }
567 
568 static inline void __trace_stack(struct trace_array *tr, unsigned long flags,
569 				 int skip, int pc)
570 {
571 }
572 #endif /* CONFIG_STACKTRACE */
573 
574 extern cycle_t ftrace_now(int cpu);
575 
576 extern void trace_find_cmdline(int pid, char comm[]);
577 
578 #ifdef CONFIG_DYNAMIC_FTRACE
579 extern unsigned long ftrace_update_tot_cnt;
580 #endif
581 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
582 extern int DYN_FTRACE_TEST_NAME(void);
583 #define DYN_FTRACE_TEST_NAME2 trace_selftest_dynamic_test_func2
584 extern int DYN_FTRACE_TEST_NAME2(void);
585 
586 extern int ring_buffer_expanded;
587 extern bool tracing_selftest_disabled;
588 DECLARE_PER_CPU(int, ftrace_cpu_disabled);
589 
590 #ifdef CONFIG_FTRACE_STARTUP_TEST
591 extern int trace_selftest_startup_function(struct tracer *trace,
592 					   struct trace_array *tr);
593 extern int trace_selftest_startup_function_graph(struct tracer *trace,
594 						 struct trace_array *tr);
595 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
596 					  struct trace_array *tr);
597 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
598 					     struct trace_array *tr);
599 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
600 						 struct trace_array *tr);
601 extern int trace_selftest_startup_wakeup(struct tracer *trace,
602 					 struct trace_array *tr);
603 extern int trace_selftest_startup_nop(struct tracer *trace,
604 					 struct trace_array *tr);
605 extern int trace_selftest_startup_sched_switch(struct tracer *trace,
606 					       struct trace_array *tr);
607 extern int trace_selftest_startup_branch(struct tracer *trace,
608 					 struct trace_array *tr);
609 #endif /* CONFIG_FTRACE_STARTUP_TEST */
610 
611 extern void *head_page(struct trace_array_cpu *data);
612 extern unsigned long long ns2usecs(cycle_t nsec);
613 extern int
614 trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
615 extern int
616 trace_vprintk(unsigned long ip, const char *fmt, va_list args);
617 extern int
618 trace_array_vprintk(struct trace_array *tr,
619 		    unsigned long ip, const char *fmt, va_list args);
620 int trace_array_printk(struct trace_array *tr,
621 		       unsigned long ip, const char *fmt, ...);
622 void trace_printk_seq(struct trace_seq *s);
623 enum print_line_t print_trace_line(struct trace_iterator *iter);
624 
625 extern unsigned long trace_flags;
626 
627 extern int trace_clock_id;
628 
629 /* Standard output formatting function used for function return traces */
630 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
631 
632 /* Flag options */
633 #define TRACE_GRAPH_PRINT_OVERRUN       0x1
634 #define TRACE_GRAPH_PRINT_CPU           0x2
635 #define TRACE_GRAPH_PRINT_OVERHEAD      0x4
636 #define TRACE_GRAPH_PRINT_PROC          0x8
637 #define TRACE_GRAPH_PRINT_DURATION      0x10
638 #define TRACE_GRAPH_PRINT_ABS_TIME      0x20
639 
640 extern enum print_line_t
641 print_graph_function_flags(struct trace_iterator *iter, u32 flags);
642 extern void print_graph_headers_flags(struct seq_file *s, u32 flags);
643 extern enum print_line_t
644 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
645 extern void graph_trace_open(struct trace_iterator *iter);
646 extern void graph_trace_close(struct trace_iterator *iter);
647 extern int __trace_graph_entry(struct trace_array *tr,
648 			       struct ftrace_graph_ent *trace,
649 			       unsigned long flags, int pc);
650 extern void __trace_graph_return(struct trace_array *tr,
651 				 struct ftrace_graph_ret *trace,
652 				 unsigned long flags, int pc);
653 
654 
655 #ifdef CONFIG_DYNAMIC_FTRACE
656 /* TODO: make this variable */
657 #define FTRACE_GRAPH_MAX_FUNCS		32
658 extern int ftrace_graph_filter_enabled;
659 extern int ftrace_graph_count;
660 extern unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS];
661 
662 static inline int ftrace_graph_addr(unsigned long addr)
663 {
664 	int i;
665 
666 	if (!ftrace_graph_filter_enabled)
667 		return 1;
668 
669 	for (i = 0; i < ftrace_graph_count; i++) {
670 		if (addr == ftrace_graph_funcs[i]) {
671 			/*
672 			 * If no irqs are to be traced, but a set_graph_function
673 			 * is set, and called by an interrupt handler, we still
674 			 * want to trace it.
675 			 */
676 			if (in_irq())
677 				trace_recursion_set(TRACE_IRQ_BIT);
678 			else
679 				trace_recursion_clear(TRACE_IRQ_BIT);
680 			return 1;
681 		}
682 	}
683 
684 	return 0;
685 }
686 #else
687 static inline int ftrace_graph_addr(unsigned long addr)
688 {
689 	return 1;
690 }
691 #endif /* CONFIG_DYNAMIC_FTRACE */
692 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
693 static inline enum print_line_t
694 print_graph_function_flags(struct trace_iterator *iter, u32 flags)
695 {
696 	return TRACE_TYPE_UNHANDLED;
697 }
698 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
699 
700 extern struct list_head ftrace_pids;
701 
702 #ifdef CONFIG_FUNCTION_TRACER
703 static inline int ftrace_trace_task(struct task_struct *task)
704 {
705 	if (list_empty(&ftrace_pids))
706 		return 1;
707 
708 	return test_tsk_trace_trace(task);
709 }
710 extern int ftrace_is_dead(void);
711 #else
712 static inline int ftrace_trace_task(struct task_struct *task)
713 {
714 	return 1;
715 }
716 static inline int ftrace_is_dead(void) { return 0; }
717 #endif
718 
719 int ftrace_event_is_function(struct ftrace_event_call *call);
720 
721 /*
722  * struct trace_parser - servers for reading the user input separated by spaces
723  * @cont: set if the input is not complete - no final space char was found
724  * @buffer: holds the parsed user input
725  * @idx: user input length
726  * @size: buffer size
727  */
728 struct trace_parser {
729 	bool		cont;
730 	char		*buffer;
731 	unsigned	idx;
732 	unsigned	size;
733 };
734 
735 static inline bool trace_parser_loaded(struct trace_parser *parser)
736 {
737 	return (parser->idx != 0);
738 }
739 
740 static inline bool trace_parser_cont(struct trace_parser *parser)
741 {
742 	return parser->cont;
743 }
744 
745 static inline void trace_parser_clear(struct trace_parser *parser)
746 {
747 	parser->cont = false;
748 	parser->idx = 0;
749 }
750 
751 extern int trace_parser_get_init(struct trace_parser *parser, int size);
752 extern void trace_parser_put(struct trace_parser *parser);
753 extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
754 	size_t cnt, loff_t *ppos);
755 
756 /*
757  * trace_iterator_flags is an enumeration that defines bit
758  * positions into trace_flags that controls the output.
759  *
760  * NOTE: These bits must match the trace_options array in
761  *       trace.c.
762  */
763 enum trace_iterator_flags {
764 	TRACE_ITER_PRINT_PARENT		= 0x01,
765 	TRACE_ITER_SYM_OFFSET		= 0x02,
766 	TRACE_ITER_SYM_ADDR		= 0x04,
767 	TRACE_ITER_VERBOSE		= 0x08,
768 	TRACE_ITER_RAW			= 0x10,
769 	TRACE_ITER_HEX			= 0x20,
770 	TRACE_ITER_BIN			= 0x40,
771 	TRACE_ITER_BLOCK		= 0x80,
772 	TRACE_ITER_STACKTRACE		= 0x100,
773 	TRACE_ITER_PRINTK		= 0x200,
774 	TRACE_ITER_PREEMPTONLY		= 0x400,
775 	TRACE_ITER_BRANCH		= 0x800,
776 	TRACE_ITER_ANNOTATE		= 0x1000,
777 	TRACE_ITER_USERSTACKTRACE       = 0x2000,
778 	TRACE_ITER_SYM_USEROBJ          = 0x4000,
779 	TRACE_ITER_PRINTK_MSGONLY	= 0x8000,
780 	TRACE_ITER_CONTEXT_INFO		= 0x10000, /* Print pid/cpu/time */
781 	TRACE_ITER_LATENCY_FMT		= 0x20000,
782 	TRACE_ITER_SLEEP_TIME		= 0x40000,
783 	TRACE_ITER_GRAPH_TIME		= 0x80000,
784 	TRACE_ITER_RECORD_CMD		= 0x100000,
785 	TRACE_ITER_OVERWRITE		= 0x200000,
786 	TRACE_ITER_STOP_ON_FREE		= 0x400000,
787 	TRACE_ITER_IRQ_INFO		= 0x800000,
788 	TRACE_ITER_MARKERS		= 0x1000000,
789 };
790 
791 /*
792  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
793  * control the output of kernel symbols.
794  */
795 #define TRACE_ITER_SYM_MASK \
796 	(TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
797 
798 extern struct tracer nop_trace;
799 
800 #ifdef CONFIG_BRANCH_TRACER
801 extern int enable_branch_tracing(struct trace_array *tr);
802 extern void disable_branch_tracing(void);
803 static inline int trace_branch_enable(struct trace_array *tr)
804 {
805 	if (trace_flags & TRACE_ITER_BRANCH)
806 		return enable_branch_tracing(tr);
807 	return 0;
808 }
809 static inline void trace_branch_disable(void)
810 {
811 	/* due to races, always disable */
812 	disable_branch_tracing();
813 }
814 #else
815 static inline int trace_branch_enable(struct trace_array *tr)
816 {
817 	return 0;
818 }
819 static inline void trace_branch_disable(void)
820 {
821 }
822 #endif /* CONFIG_BRANCH_TRACER */
823 
824 /* set ring buffers to default size if not already done so */
825 int tracing_update_buffers(void);
826 
827 /* trace event type bit fields, not numeric */
828 enum {
829 	TRACE_EVENT_TYPE_PRINTF		= 1,
830 	TRACE_EVENT_TYPE_RAW		= 2,
831 };
832 
833 struct ftrace_event_field {
834 	struct list_head	link;
835 	char			*name;
836 	char			*type;
837 	int			filter_type;
838 	int			offset;
839 	int			size;
840 	int			is_signed;
841 };
842 
843 struct event_filter {
844 	int			n_preds;	/* Number assigned */
845 	int			a_preds;	/* allocated */
846 	struct filter_pred	*preds;
847 	struct filter_pred	*root;
848 	char			*filter_string;
849 };
850 
851 struct event_subsystem {
852 	struct list_head	list;
853 	const char		*name;
854 	struct dentry		*entry;
855 	struct event_filter	*filter;
856 	int			nr_events;
857 	int			ref_count;
858 };
859 
860 #define FILTER_PRED_INVALID	((unsigned short)-1)
861 #define FILTER_PRED_IS_RIGHT	(1 << 15)
862 #define FILTER_PRED_FOLD	(1 << 15)
863 
864 /*
865  * The max preds is the size of unsigned short with
866  * two flags at the MSBs. One bit is used for both the IS_RIGHT
867  * and FOLD flags. The other is reserved.
868  *
869  * 2^14 preds is way more than enough.
870  */
871 #define MAX_FILTER_PRED		16384
872 
873 struct filter_pred;
874 struct regex;
875 
876 typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event);
877 
878 typedef int (*regex_match_func)(char *str, struct regex *r, int len);
879 
880 enum regex_type {
881 	MATCH_FULL = 0,
882 	MATCH_FRONT_ONLY,
883 	MATCH_MIDDLE_ONLY,
884 	MATCH_END_ONLY,
885 };
886 
887 struct regex {
888 	char			pattern[MAX_FILTER_STR_VAL];
889 	int			len;
890 	int			field_len;
891 	regex_match_func	match;
892 };
893 
894 struct filter_pred {
895 	filter_pred_fn_t 	fn;
896 	u64 			val;
897 	struct regex		regex;
898 	unsigned short		*ops;
899 	struct ftrace_event_field *field;
900 	int 			offset;
901 	int 			not;
902 	int 			op;
903 	unsigned short		index;
904 	unsigned short		parent;
905 	unsigned short		left;
906 	unsigned short		right;
907 };
908 
909 extern struct list_head ftrace_common_fields;
910 
911 extern enum regex_type
912 filter_parse_regex(char *buff, int len, char **search, int *not);
913 extern void print_event_filter(struct ftrace_event_call *call,
914 			       struct trace_seq *s);
915 extern int apply_event_filter(struct ftrace_event_call *call,
916 			      char *filter_string);
917 extern int apply_subsystem_event_filter(struct event_subsystem *system,
918 					char *filter_string);
919 extern void print_subsystem_event_filter(struct event_subsystem *system,
920 					 struct trace_seq *s);
921 extern int filter_assign_type(const char *type);
922 
923 struct list_head *
924 trace_get_fields(struct ftrace_event_call *event_call);
925 
926 static inline int
927 filter_check_discard(struct ftrace_event_call *call, void *rec,
928 		     struct ring_buffer *buffer,
929 		     struct ring_buffer_event *event)
930 {
931 	if (unlikely(call->flags & TRACE_EVENT_FL_FILTERED) &&
932 	    !filter_match_preds(call->filter, rec)) {
933 		ring_buffer_discard_commit(buffer, event);
934 		return 1;
935 	}
936 
937 	return 0;
938 }
939 
940 extern void trace_event_enable_cmd_record(bool enable);
941 
942 extern struct mutex event_mutex;
943 extern struct list_head ftrace_events;
944 
945 extern const char *__start___trace_bprintk_fmt[];
946 extern const char *__stop___trace_bprintk_fmt[];
947 
948 void trace_printk_init_buffers(void);
949 void trace_printk_start_comm(void);
950 int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set);
951 int set_tracer_flag(unsigned int mask, int enabled);
952 
953 #undef FTRACE_ENTRY
954 #define FTRACE_ENTRY(call, struct_name, id, tstruct, print, filter)	\
955 	extern struct ftrace_event_call					\
956 	__attribute__((__aligned__(4))) event_##call;
957 #undef FTRACE_ENTRY_DUP
958 #define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print, filter)	\
959 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print), \
960 		     filter)
961 #include "trace_entries.h"
962 
963 #if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_FUNCTION_TRACER)
964 int perf_ftrace_event_register(struct ftrace_event_call *call,
965 			       enum trace_reg type, void *data);
966 #else
967 #define perf_ftrace_event_register NULL
968 #endif
969 
970 #endif /* _LINUX_KERNEL_TRACE_H */
971