xref: /openbmc/linux/kernel/trace/trace.h (revision 82ced6fd)
1 #ifndef _LINUX_KERNEL_TRACE_H
2 #define _LINUX_KERNEL_TRACE_H
3 
4 #include <linux/fs.h>
5 #include <asm/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/ftrace.h>
11 #include <trace/boot.h>
12 #include <trace/kmemtrace.h>
13 #include <trace/power.h>
14 
15 enum trace_type {
16 	__TRACE_FIRST_TYPE = 0,
17 
18 	TRACE_FN,
19 	TRACE_CTX,
20 	TRACE_WAKE,
21 	TRACE_STACK,
22 	TRACE_PRINT,
23 	TRACE_BPRINT,
24 	TRACE_SPECIAL,
25 	TRACE_MMIO_RW,
26 	TRACE_MMIO_MAP,
27 	TRACE_BRANCH,
28 	TRACE_BOOT_CALL,
29 	TRACE_BOOT_RET,
30 	TRACE_GRAPH_RET,
31 	TRACE_GRAPH_ENT,
32 	TRACE_USER_STACK,
33 	TRACE_HW_BRANCHES,
34 	TRACE_SYSCALL_ENTER,
35 	TRACE_SYSCALL_EXIT,
36 	TRACE_KMEM_ALLOC,
37 	TRACE_KMEM_FREE,
38 	TRACE_POWER,
39 	TRACE_BLK,
40 
41 	__TRACE_LAST_TYPE,
42 };
43 
44 /*
45  * The trace entry - the most basic unit of tracing. This is what
46  * is printed in the end as a single line in the trace output, such as:
47  *
48  *     bash-15816 [01]   235.197585: idle_cpu <- irq_enter
49  */
50 struct trace_entry {
51 	unsigned char		type;
52 	unsigned char		flags;
53 	unsigned char		preempt_count;
54 	int			pid;
55 	int			tgid;
56 };
57 
58 /*
59  * Function trace entry - function address and parent function addres:
60  */
61 struct ftrace_entry {
62 	struct trace_entry	ent;
63 	unsigned long		ip;
64 	unsigned long		parent_ip;
65 };
66 
67 /* Function call entry */
68 struct ftrace_graph_ent_entry {
69 	struct trace_entry		ent;
70 	struct ftrace_graph_ent		graph_ent;
71 };
72 
73 /* Function return entry */
74 struct ftrace_graph_ret_entry {
75 	struct trace_entry		ent;
76 	struct ftrace_graph_ret		ret;
77 };
78 extern struct tracer boot_tracer;
79 
80 /*
81  * Context switch trace entry - which task (and prio) we switched from/to:
82  */
83 struct ctx_switch_entry {
84 	struct trace_entry	ent;
85 	unsigned int		prev_pid;
86 	unsigned char		prev_prio;
87 	unsigned char		prev_state;
88 	unsigned int		next_pid;
89 	unsigned char		next_prio;
90 	unsigned char		next_state;
91 	unsigned int		next_cpu;
92 };
93 
94 /*
95  * Special (free-form) trace entry:
96  */
97 struct special_entry {
98 	struct trace_entry	ent;
99 	unsigned long		arg1;
100 	unsigned long		arg2;
101 	unsigned long		arg3;
102 };
103 
104 /*
105  * Stack-trace entry:
106  */
107 
108 #define FTRACE_STACK_ENTRIES	8
109 
110 struct stack_entry {
111 	struct trace_entry	ent;
112 	unsigned long		caller[FTRACE_STACK_ENTRIES];
113 };
114 
115 struct userstack_entry {
116 	struct trace_entry	ent;
117 	unsigned long		caller[FTRACE_STACK_ENTRIES];
118 };
119 
120 /*
121  * trace_printk entry:
122  */
123 struct bprint_entry {
124 	struct trace_entry	ent;
125 	unsigned long		ip;
126 	const char		*fmt;
127 	u32			buf[];
128 };
129 
130 struct print_entry {
131 	struct trace_entry	ent;
132 	unsigned long		ip;
133 	char			buf[];
134 };
135 
136 #define TRACE_OLD_SIZE		88
137 
138 struct trace_field_cont {
139 	unsigned char		type;
140 	/* Temporary till we get rid of this completely */
141 	char			buf[TRACE_OLD_SIZE - 1];
142 };
143 
144 struct trace_mmiotrace_rw {
145 	struct trace_entry	ent;
146 	struct mmiotrace_rw	rw;
147 };
148 
149 struct trace_mmiotrace_map {
150 	struct trace_entry	ent;
151 	struct mmiotrace_map	map;
152 };
153 
154 struct trace_boot_call {
155 	struct trace_entry	ent;
156 	struct boot_trace_call boot_call;
157 };
158 
159 struct trace_boot_ret {
160 	struct trace_entry	ent;
161 	struct boot_trace_ret boot_ret;
162 };
163 
164 #define TRACE_FUNC_SIZE 30
165 #define TRACE_FILE_SIZE 20
166 struct trace_branch {
167 	struct trace_entry	ent;
168 	unsigned	        line;
169 	char			func[TRACE_FUNC_SIZE+1];
170 	char			file[TRACE_FILE_SIZE+1];
171 	char			correct;
172 };
173 
174 struct hw_branch_entry {
175 	struct trace_entry	ent;
176 	u64			from;
177 	u64			to;
178 };
179 
180 struct trace_power {
181 	struct trace_entry	ent;
182 	struct power_trace	state_data;
183 };
184 
185 enum kmemtrace_type_id {
186 	KMEMTRACE_TYPE_KMALLOC = 0,	/* kmalloc() or kfree(). */
187 	KMEMTRACE_TYPE_CACHE,		/* kmem_cache_*(). */
188 	KMEMTRACE_TYPE_PAGES,		/* __get_free_pages() and friends. */
189 };
190 
191 struct kmemtrace_alloc_entry {
192 	struct trace_entry	ent;
193 	enum kmemtrace_type_id type_id;
194 	unsigned long call_site;
195 	const void *ptr;
196 	size_t bytes_req;
197 	size_t bytes_alloc;
198 	gfp_t gfp_flags;
199 	int node;
200 };
201 
202 struct kmemtrace_free_entry {
203 	struct trace_entry	ent;
204 	enum kmemtrace_type_id type_id;
205 	unsigned long call_site;
206 	const void *ptr;
207 };
208 
209 struct syscall_trace_enter {
210 	struct trace_entry	ent;
211 	int			nr;
212 	unsigned long		args[];
213 };
214 
215 struct syscall_trace_exit {
216 	struct trace_entry	ent;
217 	int			nr;
218 	unsigned long		ret;
219 };
220 
221 
222 /*
223  * trace_flag_type is an enumeration that holds different
224  * states when a trace occurs. These are:
225  *  IRQS_OFF		- interrupts were disabled
226  *  IRQS_NOSUPPORT	- arch does not support irqs_disabled_flags
227  *  NEED_RESCED		- reschedule is requested
228  *  HARDIRQ		- inside an interrupt handler
229  *  SOFTIRQ		- inside a softirq handler
230  */
231 enum trace_flag_type {
232 	TRACE_FLAG_IRQS_OFF		= 0x01,
233 	TRACE_FLAG_IRQS_NOSUPPORT	= 0x02,
234 	TRACE_FLAG_NEED_RESCHED		= 0x04,
235 	TRACE_FLAG_HARDIRQ		= 0x08,
236 	TRACE_FLAG_SOFTIRQ		= 0x10,
237 };
238 
239 #define TRACE_BUF_SIZE		1024
240 
241 /*
242  * The CPU trace array - it consists of thousands of trace entries
243  * plus some other descriptor data: (for example which task started
244  * the trace, etc.)
245  */
246 struct trace_array_cpu {
247 	atomic_t		disabled;
248 	void			*buffer_page;	/* ring buffer spare */
249 
250 	/* these fields get copied into max-trace: */
251 	unsigned long		trace_idx;
252 	unsigned long		overrun;
253 	unsigned long		saved_latency;
254 	unsigned long		critical_start;
255 	unsigned long		critical_end;
256 	unsigned long		critical_sequence;
257 	unsigned long		nice;
258 	unsigned long		policy;
259 	unsigned long		rt_priority;
260 	cycle_t			preempt_timestamp;
261 	pid_t			pid;
262 	uid_t			uid;
263 	char			comm[TASK_COMM_LEN];
264 };
265 
266 struct trace_iterator;
267 
268 /*
269  * The trace array - an array of per-CPU trace arrays. This is the
270  * highest level data structure that individual tracers deal with.
271  * They have on/off state as well:
272  */
273 struct trace_array {
274 	struct ring_buffer	*buffer;
275 	unsigned long		entries;
276 	int			cpu;
277 	cycle_t			time_start;
278 	struct task_struct	*waiter;
279 	struct trace_array_cpu	*data[NR_CPUS];
280 };
281 
282 #define FTRACE_CMP_TYPE(var, type) \
283 	__builtin_types_compatible_p(typeof(var), type *)
284 
285 #undef IF_ASSIGN
286 #define IF_ASSIGN(var, entry, etype, id)		\
287 	if (FTRACE_CMP_TYPE(var, etype)) {		\
288 		var = (typeof(var))(entry);		\
289 		WARN_ON(id && (entry)->type != id);	\
290 		break;					\
291 	}
292 
293 /* Will cause compile errors if type is not found. */
294 extern void __ftrace_bad_type(void);
295 
296 /*
297  * The trace_assign_type is a verifier that the entry type is
298  * the same as the type being assigned. To add new types simply
299  * add a line with the following format:
300  *
301  * IF_ASSIGN(var, ent, type, id);
302  *
303  *  Where "type" is the trace type that includes the trace_entry
304  *  as the "ent" item. And "id" is the trace identifier that is
305  *  used in the trace_type enum.
306  *
307  *  If the type can have more than one id, then use zero.
308  */
309 #define trace_assign_type(var, ent)					\
310 	do {								\
311 		IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);	\
312 		IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);	\
313 		IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);	\
314 		IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
315 		IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);	\
316 		IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT);	\
317 		IF_ASSIGN(var, ent, struct special_entry, 0);		\
318 		IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,		\
319 			  TRACE_MMIO_RW);				\
320 		IF_ASSIGN(var, ent, struct trace_mmiotrace_map,		\
321 			  TRACE_MMIO_MAP);				\
322 		IF_ASSIGN(var, ent, struct trace_boot_call, TRACE_BOOT_CALL);\
323 		IF_ASSIGN(var, ent, struct trace_boot_ret, TRACE_BOOT_RET);\
324 		IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
325 		IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,	\
326 			  TRACE_GRAPH_ENT);		\
327 		IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,	\
328 			  TRACE_GRAPH_RET);		\
329 		IF_ASSIGN(var, ent, struct hw_branch_entry, TRACE_HW_BRANCHES);\
330 		IF_ASSIGN(var, ent, struct trace_power, TRACE_POWER); \
331 		IF_ASSIGN(var, ent, struct kmemtrace_alloc_entry,	\
332 			  TRACE_KMEM_ALLOC);	\
333 		IF_ASSIGN(var, ent, struct kmemtrace_free_entry,	\
334 			  TRACE_KMEM_FREE);	\
335 		IF_ASSIGN(var, ent, struct syscall_trace_enter,		\
336 			  TRACE_SYSCALL_ENTER);				\
337 		IF_ASSIGN(var, ent, struct syscall_trace_exit,		\
338 			  TRACE_SYSCALL_EXIT);				\
339 		__ftrace_bad_type();					\
340 	} while (0)
341 
342 /* Return values for print_line callback */
343 enum print_line_t {
344 	TRACE_TYPE_PARTIAL_LINE	= 0,	/* Retry after flushing the seq */
345 	TRACE_TYPE_HANDLED	= 1,
346 	TRACE_TYPE_UNHANDLED	= 2,	/* Relay to other output functions */
347 	TRACE_TYPE_NO_CONSUME	= 3	/* Handled but ask to not consume */
348 };
349 
350 
351 /*
352  * An option specific to a tracer. This is a boolean value.
353  * The bit is the bit index that sets its value on the
354  * flags value in struct tracer_flags.
355  */
356 struct tracer_opt {
357 	const char	*name; /* Will appear on the trace_options file */
358 	u32		bit; /* Mask assigned in val field in tracer_flags */
359 };
360 
361 /*
362  * The set of specific options for a tracer. Your tracer
363  * have to set the initial value of the flags val.
364  */
365 struct tracer_flags {
366 	u32			val;
367 	struct tracer_opt	*opts;
368 };
369 
370 /* Makes more easy to define a tracer opt */
371 #define TRACER_OPT(s, b)	.name = #s, .bit = b
372 
373 
374 /**
375  * struct tracer - a specific tracer and its callbacks to interact with debugfs
376  * @name: the name chosen to select it on the available_tracers file
377  * @init: called when one switches to this tracer (echo name > current_tracer)
378  * @reset: called when one switches to another tracer
379  * @start: called when tracing is unpaused (echo 1 > tracing_enabled)
380  * @stop: called when tracing is paused (echo 0 > tracing_enabled)
381  * @open: called when the trace file is opened
382  * @pipe_open: called when the trace_pipe file is opened
383  * @wait_pipe: override how the user waits for traces on trace_pipe
384  * @close: called when the trace file is released
385  * @read: override the default read callback on trace_pipe
386  * @splice_read: override the default splice_read callback on trace_pipe
387  * @selftest: selftest to run on boot (see trace_selftest.c)
388  * @print_headers: override the first lines that describe your columns
389  * @print_line: callback that prints a trace
390  * @set_flag: signals one of your private flags changed (trace_options file)
391  * @flags: your private flags
392  */
393 struct tracer {
394 	const char		*name;
395 	int			(*init)(struct trace_array *tr);
396 	void			(*reset)(struct trace_array *tr);
397 	void			(*start)(struct trace_array *tr);
398 	void			(*stop)(struct trace_array *tr);
399 	void			(*open)(struct trace_iterator *iter);
400 	void			(*pipe_open)(struct trace_iterator *iter);
401 	void			(*wait_pipe)(struct trace_iterator *iter);
402 	void			(*close)(struct trace_iterator *iter);
403 	ssize_t			(*read)(struct trace_iterator *iter,
404 					struct file *filp, char __user *ubuf,
405 					size_t cnt, loff_t *ppos);
406 	ssize_t			(*splice_read)(struct trace_iterator *iter,
407 					       struct file *filp,
408 					       loff_t *ppos,
409 					       struct pipe_inode_info *pipe,
410 					       size_t len,
411 					       unsigned int flags);
412 #ifdef CONFIG_FTRACE_STARTUP_TEST
413 	int			(*selftest)(struct tracer *trace,
414 					    struct trace_array *tr);
415 #endif
416 	void			(*print_header)(struct seq_file *m);
417 	enum print_line_t	(*print_line)(struct trace_iterator *iter);
418 	/* If you handled the flag setting, return 0 */
419 	int			(*set_flag)(u32 old_flags, u32 bit, int set);
420 	struct tracer		*next;
421 	int			print_max;
422 	struct tracer_flags	*flags;
423 	struct tracer_stat	*stats;
424 };
425 
426 struct trace_seq {
427 	unsigned char		buffer[PAGE_SIZE];
428 	unsigned int		len;
429 	unsigned int		readpos;
430 };
431 
432 static inline void
433 trace_seq_init(struct trace_seq *s)
434 {
435 	s->len = 0;
436 	s->readpos = 0;
437 }
438 
439 
440 #define TRACE_PIPE_ALL_CPU	-1
441 
442 /*
443  * Trace iterator - used by printout routines who present trace
444  * results to users and which routines might sleep, etc:
445  */
446 struct trace_iterator {
447 	struct trace_array	*tr;
448 	struct tracer		*trace;
449 	void			*private;
450 	int			cpu_file;
451 	struct mutex		mutex;
452 	struct ring_buffer_iter	*buffer_iter[NR_CPUS];
453 
454 	/* The below is zeroed out in pipe_read */
455 	struct trace_seq	seq;
456 	struct trace_entry	*ent;
457 	int			cpu;
458 	u64			ts;
459 
460 	unsigned long		iter_flags;
461 	loff_t			pos;
462 	long			idx;
463 
464 	cpumask_var_t		started;
465 };
466 
467 int tracer_init(struct tracer *t, struct trace_array *tr);
468 int tracing_is_enabled(void);
469 void trace_wake_up(void);
470 void tracing_reset(struct trace_array *tr, int cpu);
471 void tracing_reset_online_cpus(struct trace_array *tr);
472 int tracing_open_generic(struct inode *inode, struct file *filp);
473 struct dentry *tracing_init_dentry(void);
474 void init_tracer_sysprof_debugfs(struct dentry *d_tracer);
475 
476 struct ring_buffer_event;
477 
478 struct ring_buffer_event *trace_buffer_lock_reserve(struct trace_array *tr,
479 						    unsigned char type,
480 						    unsigned long len,
481 						    unsigned long flags,
482 						    int pc);
483 void trace_buffer_unlock_commit(struct trace_array *tr,
484 				struct ring_buffer_event *event,
485 				unsigned long flags, int pc);
486 
487 struct ring_buffer_event *
488 trace_current_buffer_lock_reserve(unsigned char type, unsigned long len,
489 				  unsigned long flags, int pc);
490 void trace_current_buffer_unlock_commit(struct ring_buffer_event *event,
491 					unsigned long flags, int pc);
492 void trace_nowake_buffer_unlock_commit(struct ring_buffer_event *event,
493 					unsigned long flags, int pc);
494 
495 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
496 						struct trace_array_cpu *data);
497 
498 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
499 					  int *ent_cpu, u64 *ent_ts);
500 
501 void tracing_generic_entry_update(struct trace_entry *entry,
502 				  unsigned long flags,
503 				  int pc);
504 
505 void default_wait_pipe(struct trace_iterator *iter);
506 void poll_wait_pipe(struct trace_iterator *iter);
507 
508 void ftrace(struct trace_array *tr,
509 			    struct trace_array_cpu *data,
510 			    unsigned long ip,
511 			    unsigned long parent_ip,
512 			    unsigned long flags, int pc);
513 void tracing_sched_switch_trace(struct trace_array *tr,
514 				struct task_struct *prev,
515 				struct task_struct *next,
516 				unsigned long flags, int pc);
517 void tracing_record_cmdline(struct task_struct *tsk);
518 
519 void tracing_sched_wakeup_trace(struct trace_array *tr,
520 				struct task_struct *wakee,
521 				struct task_struct *cur,
522 				unsigned long flags, int pc);
523 void trace_special(struct trace_array *tr,
524 		   struct trace_array_cpu *data,
525 		   unsigned long arg1,
526 		   unsigned long arg2,
527 		   unsigned long arg3, int pc);
528 void trace_function(struct trace_array *tr,
529 		    unsigned long ip,
530 		    unsigned long parent_ip,
531 		    unsigned long flags, int pc);
532 
533 void trace_graph_return(struct ftrace_graph_ret *trace);
534 int trace_graph_entry(struct ftrace_graph_ent *trace);
535 
536 void tracing_start_cmdline_record(void);
537 void tracing_stop_cmdline_record(void);
538 void tracing_sched_switch_assign_trace(struct trace_array *tr);
539 void tracing_stop_sched_switch_record(void);
540 void tracing_start_sched_switch_record(void);
541 int register_tracer(struct tracer *type);
542 void unregister_tracer(struct tracer *type);
543 
544 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
545 
546 extern unsigned long tracing_max_latency;
547 extern unsigned long tracing_thresh;
548 
549 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
550 void update_max_tr_single(struct trace_array *tr,
551 			  struct task_struct *tsk, int cpu);
552 
553 void __trace_stack(struct trace_array *tr,
554 		   unsigned long flags,
555 		   int skip, int pc);
556 
557 extern cycle_t ftrace_now(int cpu);
558 
559 #ifdef CONFIG_CONTEXT_SWITCH_TRACER
560 typedef void
561 (*tracer_switch_func_t)(void *private,
562 			void *__rq,
563 			struct task_struct *prev,
564 			struct task_struct *next);
565 
566 struct tracer_switch_ops {
567 	tracer_switch_func_t		func;
568 	void				*private;
569 	struct tracer_switch_ops	*next;
570 };
571 #endif /* CONFIG_CONTEXT_SWITCH_TRACER */
572 
573 extern void trace_find_cmdline(int pid, char comm[]);
574 
575 #ifdef CONFIG_DYNAMIC_FTRACE
576 extern unsigned long ftrace_update_tot_cnt;
577 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
578 extern int DYN_FTRACE_TEST_NAME(void);
579 #endif
580 
581 #ifdef CONFIG_FTRACE_STARTUP_TEST
582 extern int trace_selftest_startup_function(struct tracer *trace,
583 					   struct trace_array *tr);
584 extern int trace_selftest_startup_function_graph(struct tracer *trace,
585 						 struct trace_array *tr);
586 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
587 					  struct trace_array *tr);
588 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
589 					     struct trace_array *tr);
590 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
591 						 struct trace_array *tr);
592 extern int trace_selftest_startup_wakeup(struct tracer *trace,
593 					 struct trace_array *tr);
594 extern int trace_selftest_startup_nop(struct tracer *trace,
595 					 struct trace_array *tr);
596 extern int trace_selftest_startup_sched_switch(struct tracer *trace,
597 					       struct trace_array *tr);
598 extern int trace_selftest_startup_sysprof(struct tracer *trace,
599 					       struct trace_array *tr);
600 extern int trace_selftest_startup_branch(struct tracer *trace,
601 					 struct trace_array *tr);
602 #endif /* CONFIG_FTRACE_STARTUP_TEST */
603 
604 extern void *head_page(struct trace_array_cpu *data);
605 extern unsigned long long ns2usecs(cycle_t nsec);
606 extern int
607 trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
608 extern int
609 trace_vprintk(unsigned long ip, const char *fmt, va_list args);
610 
611 extern unsigned long trace_flags;
612 
613 /* Standard output formatting function used for function return traces */
614 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
615 extern enum print_line_t print_graph_function(struct trace_iterator *iter);
616 
617 #ifdef CONFIG_DYNAMIC_FTRACE
618 /* TODO: make this variable */
619 #define FTRACE_GRAPH_MAX_FUNCS		32
620 extern int ftrace_graph_count;
621 extern unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS];
622 
623 static inline int ftrace_graph_addr(unsigned long addr)
624 {
625 	int i;
626 
627 	if (!ftrace_graph_count || test_tsk_trace_graph(current))
628 		return 1;
629 
630 	for (i = 0; i < ftrace_graph_count; i++) {
631 		if (addr == ftrace_graph_funcs[i])
632 			return 1;
633 	}
634 
635 	return 0;
636 }
637 #else
638 static inline int ftrace_trace_addr(unsigned long addr)
639 {
640 	return 1;
641 }
642 static inline int ftrace_graph_addr(unsigned long addr)
643 {
644 	return 1;
645 }
646 #endif /* CONFIG_DYNAMIC_FTRACE */
647 
648 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
649 static inline enum print_line_t
650 print_graph_function(struct trace_iterator *iter)
651 {
652 	return TRACE_TYPE_UNHANDLED;
653 }
654 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
655 
656 extern struct pid *ftrace_pid_trace;
657 
658 static inline int ftrace_trace_task(struct task_struct *task)
659 {
660 	if (!ftrace_pid_trace)
661 		return 1;
662 
663 	return test_tsk_trace_trace(task);
664 }
665 
666 /*
667  * trace_iterator_flags is an enumeration that defines bit
668  * positions into trace_flags that controls the output.
669  *
670  * NOTE: These bits must match the trace_options array in
671  *       trace.c.
672  */
673 enum trace_iterator_flags {
674 	TRACE_ITER_PRINT_PARENT		= 0x01,
675 	TRACE_ITER_SYM_OFFSET		= 0x02,
676 	TRACE_ITER_SYM_ADDR		= 0x04,
677 	TRACE_ITER_VERBOSE		= 0x08,
678 	TRACE_ITER_RAW			= 0x10,
679 	TRACE_ITER_HEX			= 0x20,
680 	TRACE_ITER_BIN			= 0x40,
681 	TRACE_ITER_BLOCK		= 0x80,
682 	TRACE_ITER_STACKTRACE		= 0x100,
683 	TRACE_ITER_SCHED_TREE		= 0x200,
684 	TRACE_ITER_PRINTK		= 0x400,
685 	TRACE_ITER_PREEMPTONLY		= 0x800,
686 	TRACE_ITER_BRANCH		= 0x1000,
687 	TRACE_ITER_ANNOTATE		= 0x2000,
688 	TRACE_ITER_USERSTACKTRACE       = 0x4000,
689 	TRACE_ITER_SYM_USEROBJ          = 0x8000,
690 	TRACE_ITER_PRINTK_MSGONLY	= 0x10000,
691 	TRACE_ITER_CONTEXT_INFO		= 0x20000, /* Print pid/cpu/time */
692 	TRACE_ITER_LATENCY_FMT		= 0x40000,
693 	TRACE_ITER_GLOBAL_CLK		= 0x80000,
694 	TRACE_ITER_SLEEP_TIME		= 0x100000,
695 };
696 
697 /*
698  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
699  * control the output of kernel symbols.
700  */
701 #define TRACE_ITER_SYM_MASK \
702 	(TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
703 
704 extern struct tracer nop_trace;
705 
706 /**
707  * ftrace_preempt_disable - disable preemption scheduler safe
708  *
709  * When tracing can happen inside the scheduler, there exists
710  * cases that the tracing might happen before the need_resched
711  * flag is checked. If this happens and the tracer calls
712  * preempt_enable (after a disable), a schedule might take place
713  * causing an infinite recursion.
714  *
715  * To prevent this, we read the need_resched flag before
716  * disabling preemption. When we want to enable preemption we
717  * check the flag, if it is set, then we call preempt_enable_no_resched.
718  * Otherwise, we call preempt_enable.
719  *
720  * The rational for doing the above is that if need_resched is set
721  * and we have yet to reschedule, we are either in an atomic location
722  * (where we do not need to check for scheduling) or we are inside
723  * the scheduler and do not want to resched.
724  */
725 static inline int ftrace_preempt_disable(void)
726 {
727 	int resched;
728 
729 	resched = need_resched();
730 	preempt_disable_notrace();
731 
732 	return resched;
733 }
734 
735 /**
736  * ftrace_preempt_enable - enable preemption scheduler safe
737  * @resched: the return value from ftrace_preempt_disable
738  *
739  * This is a scheduler safe way to enable preemption and not miss
740  * any preemption checks. The disabled saved the state of preemption.
741  * If resched is set, then we are either inside an atomic or
742  * are inside the scheduler (we would have already scheduled
743  * otherwise). In this case, we do not want to call normal
744  * preempt_enable, but preempt_enable_no_resched instead.
745  */
746 static inline void ftrace_preempt_enable(int resched)
747 {
748 	if (resched)
749 		preempt_enable_no_resched_notrace();
750 	else
751 		preempt_enable_notrace();
752 }
753 
754 #ifdef CONFIG_BRANCH_TRACER
755 extern int enable_branch_tracing(struct trace_array *tr);
756 extern void disable_branch_tracing(void);
757 static inline int trace_branch_enable(struct trace_array *tr)
758 {
759 	if (trace_flags & TRACE_ITER_BRANCH)
760 		return enable_branch_tracing(tr);
761 	return 0;
762 }
763 static inline void trace_branch_disable(void)
764 {
765 	/* due to races, always disable */
766 	disable_branch_tracing();
767 }
768 #else
769 static inline int trace_branch_enable(struct trace_array *tr)
770 {
771 	return 0;
772 }
773 static inline void trace_branch_disable(void)
774 {
775 }
776 #endif /* CONFIG_BRANCH_TRACER */
777 
778 /* set ring buffers to default size if not already done so */
779 int tracing_update_buffers(void);
780 
781 /* trace event type bit fields, not numeric */
782 enum {
783 	TRACE_EVENT_TYPE_PRINTF		= 1,
784 	TRACE_EVENT_TYPE_RAW		= 2,
785 };
786 
787 struct ftrace_event_field {
788 	struct list_head	link;
789 	char			*name;
790 	char			*type;
791 	int			offset;
792 	int			size;
793 };
794 
795 struct ftrace_event_call {
796 	char			*name;
797 	char			*system;
798 	struct dentry		*dir;
799 	int			enabled;
800 	int			(*regfunc)(void);
801 	void			(*unregfunc)(void);
802 	int			id;
803 	int			(*raw_init)(void);
804 	int			(*show_format)(struct trace_seq *s);
805 	int			(*define_fields)(void);
806 	struct list_head	fields;
807 	struct filter_pred	**preds;
808 
809 #ifdef CONFIG_EVENT_PROFILE
810 	atomic_t	profile_count;
811 	int		(*profile_enable)(struct ftrace_event_call *);
812 	void		(*profile_disable)(struct ftrace_event_call *);
813 #endif
814 };
815 
816 struct event_subsystem {
817 	struct list_head	list;
818 	const char		*name;
819 	struct dentry		*entry;
820 	struct filter_pred	**preds;
821 };
822 
823 #define events_for_each(event)						\
824 	for (event = __start_ftrace_events;				\
825 	     (unsigned long)event < (unsigned long)__stop_ftrace_events; \
826 	     event++)
827 
828 #define MAX_FILTER_PRED 8
829 
830 struct filter_pred;
831 
832 typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event);
833 
834 struct filter_pred {
835 	filter_pred_fn_t fn;
836 	u64 val;
837 	char *str_val;
838 	int str_len;
839 	char *field_name;
840 	int offset;
841 	int not;
842 	int or;
843 	int compound;
844 	int clear;
845 };
846 
847 int trace_define_field(struct ftrace_event_call *call, char *type,
848 		       char *name, int offset, int size);
849 extern void filter_free_pred(struct filter_pred *pred);
850 extern void filter_print_preds(struct filter_pred **preds,
851 			       struct trace_seq *s);
852 extern int filter_parse(char **pbuf, struct filter_pred *pred);
853 extern int filter_add_pred(struct ftrace_event_call *call,
854 			   struct filter_pred *pred);
855 extern void filter_free_preds(struct ftrace_event_call *call);
856 extern int filter_match_preds(struct ftrace_event_call *call, void *rec);
857 extern void filter_free_subsystem_preds(struct event_subsystem *system);
858 extern int filter_add_subsystem_pred(struct event_subsystem *system,
859 				     struct filter_pred *pred);
860 
861 void event_trace_printk(unsigned long ip, const char *fmt, ...);
862 extern struct ftrace_event_call __start_ftrace_events[];
863 extern struct ftrace_event_call __stop_ftrace_events[];
864 
865 #define for_each_event(event)						\
866 	for (event = __start_ftrace_events;				\
867 	     (unsigned long)event < (unsigned long)__stop_ftrace_events; \
868 	     event++)
869 
870 extern const char *__start___trace_bprintk_fmt[];
871 extern const char *__stop___trace_bprintk_fmt[];
872 
873 /*
874  * The double __builtin_constant_p is because gcc will give us an error
875  * if we try to allocate the static variable to fmt if it is not a
876  * constant. Even with the outer if statement optimizing out.
877  */
878 #define event_trace_printk(ip, fmt, args...)				\
879 do {									\
880 	__trace_printk_check_format(fmt, ##args);			\
881 	tracing_record_cmdline(current);				\
882 	if (__builtin_constant_p(fmt)) {				\
883 		static const char *trace_printk_fmt			\
884 		  __attribute__((section("__trace_printk_fmt"))) =	\
885 			__builtin_constant_p(fmt) ? fmt : NULL;		\
886 									\
887 		__trace_bprintk(ip, trace_printk_fmt, ##args);		\
888 	} else								\
889 		__trace_printk(ip, fmt, ##args);			\
890 } while (0)
891 
892 #endif /* _LINUX_KERNEL_TRACE_H */
893