xref: /openbmc/linux/kernel/trace/trace.h (revision 089a49b6)
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 };
128 
129 #define TRACE_BUF_SIZE		1024
130 
131 struct trace_array;
132 
133 /*
134  * The CPU trace array - it consists of thousands of trace entries
135  * plus some other descriptor data: (for example which task started
136  * the trace, etc.)
137  */
138 struct trace_array_cpu {
139 	atomic_t		disabled;
140 	void			*buffer_page;	/* ring buffer spare */
141 
142 	unsigned long		entries;
143 	unsigned long		saved_latency;
144 	unsigned long		critical_start;
145 	unsigned long		critical_end;
146 	unsigned long		critical_sequence;
147 	unsigned long		nice;
148 	unsigned long		policy;
149 	unsigned long		rt_priority;
150 	unsigned long		skipped_entries;
151 	cycle_t			preempt_timestamp;
152 	pid_t			pid;
153 	kuid_t			uid;
154 	char			comm[TASK_COMM_LEN];
155 };
156 
157 struct tracer;
158 
159 struct trace_buffer {
160 	struct trace_array		*tr;
161 	struct ring_buffer		*buffer;
162 	struct trace_array_cpu __percpu	*data;
163 	cycle_t				time_start;
164 	int				cpu;
165 };
166 
167 /*
168  * The trace array - an array of per-CPU trace arrays. This is the
169  * highest level data structure that individual tracers deal with.
170  * They have on/off state as well:
171  */
172 struct trace_array {
173 	struct list_head	list;
174 	char			*name;
175 	struct trace_buffer	trace_buffer;
176 #ifdef CONFIG_TRACER_MAX_TRACE
177 	/*
178 	 * The max_buffer is used to snapshot the trace when a maximum
179 	 * latency is reached, or when the user initiates a snapshot.
180 	 * Some tracers will use this to store a maximum trace while
181 	 * it continues examining live traces.
182 	 *
183 	 * The buffers for the max_buffer are set up the same as the trace_buffer
184 	 * When a snapshot is taken, the buffer of the max_buffer is swapped
185 	 * with the buffer of the trace_buffer and the buffers are reset for
186 	 * the trace_buffer so the tracing can continue.
187 	 */
188 	struct trace_buffer	max_buffer;
189 	bool			allocated_snapshot;
190 #endif
191 	int			buffer_disabled;
192 #ifdef CONFIG_FTRACE_SYSCALLS
193 	int			sys_refcount_enter;
194 	int			sys_refcount_exit;
195 	DECLARE_BITMAP(enabled_enter_syscalls, NR_syscalls);
196 	DECLARE_BITMAP(enabled_exit_syscalls, NR_syscalls);
197 #endif
198 	int			stop_count;
199 	int			clock_id;
200 	struct tracer		*current_trace;
201 	unsigned int		flags;
202 	raw_spinlock_t		start_lock;
203 	struct dentry		*dir;
204 	struct dentry		*options;
205 	struct dentry		*percpu_dir;
206 	struct dentry		*event_dir;
207 	struct list_head	systems;
208 	struct list_head	events;
209 	cpumask_var_t		tracing_cpumask; /* only trace on set CPUs */
210 	int			ref;
211 };
212 
213 enum {
214 	TRACE_ARRAY_FL_GLOBAL	= (1 << 0)
215 };
216 
217 extern struct list_head ftrace_trace_arrays;
218 
219 extern struct mutex trace_types_lock;
220 
221 extern int trace_array_get(struct trace_array *tr);
222 extern void trace_array_put(struct trace_array *tr);
223 
224 /*
225  * The global tracer (top) should be the first trace array added,
226  * but we check the flag anyway.
227  */
228 static inline struct trace_array *top_trace_array(void)
229 {
230 	struct trace_array *tr;
231 
232 	tr = list_entry(ftrace_trace_arrays.prev,
233 			typeof(*tr), list);
234 	WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
235 	return tr;
236 }
237 
238 #define FTRACE_CMP_TYPE(var, type) \
239 	__builtin_types_compatible_p(typeof(var), type *)
240 
241 #undef IF_ASSIGN
242 #define IF_ASSIGN(var, entry, etype, id)		\
243 	if (FTRACE_CMP_TYPE(var, etype)) {		\
244 		var = (typeof(var))(entry);		\
245 		WARN_ON(id && (entry)->type != id);	\
246 		break;					\
247 	}
248 
249 /* Will cause compile errors if type is not found. */
250 extern void __ftrace_bad_type(void);
251 
252 /*
253  * The trace_assign_type is a verifier that the entry type is
254  * the same as the type being assigned. To add new types simply
255  * add a line with the following format:
256  *
257  * IF_ASSIGN(var, ent, type, id);
258  *
259  *  Where "type" is the trace type that includes the trace_entry
260  *  as the "ent" item. And "id" is the trace identifier that is
261  *  used in the trace_type enum.
262  *
263  *  If the type can have more than one id, then use zero.
264  */
265 #define trace_assign_type(var, ent)					\
266 	do {								\
267 		IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);	\
268 		IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);	\
269 		IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);	\
270 		IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
271 		IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);	\
272 		IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT);	\
273 		IF_ASSIGN(var, ent, struct bputs_entry, TRACE_BPUTS);	\
274 		IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,		\
275 			  TRACE_MMIO_RW);				\
276 		IF_ASSIGN(var, ent, struct trace_mmiotrace_map,		\
277 			  TRACE_MMIO_MAP);				\
278 		IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
279 		IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,	\
280 			  TRACE_GRAPH_ENT);		\
281 		IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,	\
282 			  TRACE_GRAPH_RET);		\
283 		__ftrace_bad_type();					\
284 	} while (0)
285 
286 /*
287  * An option specific to a tracer. This is a boolean value.
288  * The bit is the bit index that sets its value on the
289  * flags value in struct tracer_flags.
290  */
291 struct tracer_opt {
292 	const char	*name; /* Will appear on the trace_options file */
293 	u32		bit; /* Mask assigned in val field in tracer_flags */
294 };
295 
296 /*
297  * The set of specific options for a tracer. Your tracer
298  * have to set the initial value of the flags val.
299  */
300 struct tracer_flags {
301 	u32			val;
302 	struct tracer_opt	*opts;
303 };
304 
305 /* Makes more easy to define a tracer opt */
306 #define TRACER_OPT(s, b)	.name = #s, .bit = b
307 
308 
309 /**
310  * struct tracer - a specific tracer and its callbacks to interact with debugfs
311  * @name: the name chosen to select it on the available_tracers file
312  * @init: called when one switches to this tracer (echo name > current_tracer)
313  * @reset: called when one switches to another tracer
314  * @start: called when tracing is unpaused (echo 1 > tracing_enabled)
315  * @stop: called when tracing is paused (echo 0 > tracing_enabled)
316  * @open: called when the trace file is opened
317  * @pipe_open: called when the trace_pipe file is opened
318  * @wait_pipe: override how the user waits for traces on trace_pipe
319  * @close: called when the trace file is released
320  * @pipe_close: called when the trace_pipe file is released
321  * @read: override the default read callback on trace_pipe
322  * @splice_read: override the default splice_read callback on trace_pipe
323  * @selftest: selftest to run on boot (see trace_selftest.c)
324  * @print_headers: override the first lines that describe your columns
325  * @print_line: callback that prints a trace
326  * @set_flag: signals one of your private flags changed (trace_options file)
327  * @flags: your private flags
328  */
329 struct tracer {
330 	const char		*name;
331 	int			(*init)(struct trace_array *tr);
332 	void			(*reset)(struct trace_array *tr);
333 	void			(*start)(struct trace_array *tr);
334 	void			(*stop)(struct trace_array *tr);
335 	void			(*open)(struct trace_iterator *iter);
336 	void			(*pipe_open)(struct trace_iterator *iter);
337 	void			(*wait_pipe)(struct trace_iterator *iter);
338 	void			(*close)(struct trace_iterator *iter);
339 	void			(*pipe_close)(struct trace_iterator *iter);
340 	ssize_t			(*read)(struct trace_iterator *iter,
341 					struct file *filp, char __user *ubuf,
342 					size_t cnt, loff_t *ppos);
343 	ssize_t			(*splice_read)(struct trace_iterator *iter,
344 					       struct file *filp,
345 					       loff_t *ppos,
346 					       struct pipe_inode_info *pipe,
347 					       size_t len,
348 					       unsigned int flags);
349 #ifdef CONFIG_FTRACE_STARTUP_TEST
350 	int			(*selftest)(struct tracer *trace,
351 					    struct trace_array *tr);
352 #endif
353 	void			(*print_header)(struct seq_file *m);
354 	enum print_line_t	(*print_line)(struct trace_iterator *iter);
355 	/* If you handled the flag setting, return 0 */
356 	int			(*set_flag)(u32 old_flags, u32 bit, int set);
357 	/* Return 0 if OK with change, else return non-zero */
358 	int			(*flag_changed)(struct tracer *tracer,
359 						u32 mask, int set);
360 	struct tracer		*next;
361 	struct tracer_flags	*flags;
362 	bool			print_max;
363 	bool			enabled;
364 #ifdef CONFIG_TRACER_MAX_TRACE
365 	bool			use_max_tr;
366 #endif
367 };
368 
369 
370 /* Only current can touch trace_recursion */
371 
372 /*
373  * For function tracing recursion:
374  *  The order of these bits are important.
375  *
376  *  When function tracing occurs, the following steps are made:
377  *   If arch does not support a ftrace feature:
378  *    call internal function (uses INTERNAL bits) which calls...
379  *   If callback is registered to the "global" list, the list
380  *    function is called and recursion checks the GLOBAL bits.
381  *    then this function calls...
382  *   The function callback, which can use the FTRACE bits to
383  *    check for recursion.
384  *
385  * Now if the arch does not suppport a feature, and it calls
386  * the global list function which calls the ftrace callback
387  * all three of these steps will do a recursion protection.
388  * There's no reason to do one if the previous caller already
389  * did. The recursion that we are protecting against will
390  * go through the same steps again.
391  *
392  * To prevent the multiple recursion checks, if a recursion
393  * bit is set that is higher than the MAX bit of the current
394  * check, then we know that the check was made by the previous
395  * caller, and we can skip the current check.
396  */
397 enum {
398 	TRACE_BUFFER_BIT,
399 	TRACE_BUFFER_NMI_BIT,
400 	TRACE_BUFFER_IRQ_BIT,
401 	TRACE_BUFFER_SIRQ_BIT,
402 
403 	/* Start of function recursion bits */
404 	TRACE_FTRACE_BIT,
405 	TRACE_FTRACE_NMI_BIT,
406 	TRACE_FTRACE_IRQ_BIT,
407 	TRACE_FTRACE_SIRQ_BIT,
408 
409 	/* GLOBAL_BITs must be greater than FTRACE_BITs */
410 	TRACE_GLOBAL_BIT,
411 	TRACE_GLOBAL_NMI_BIT,
412 	TRACE_GLOBAL_IRQ_BIT,
413 	TRACE_GLOBAL_SIRQ_BIT,
414 
415 	/* INTERNAL_BITs must be greater than GLOBAL_BITs */
416 	TRACE_INTERNAL_BIT,
417 	TRACE_INTERNAL_NMI_BIT,
418 	TRACE_INTERNAL_IRQ_BIT,
419 	TRACE_INTERNAL_SIRQ_BIT,
420 
421 	TRACE_CONTROL_BIT,
422 
423 /*
424  * Abuse of the trace_recursion.
425  * As we need a way to maintain state if we are tracing the function
426  * graph in irq because we want to trace a particular function that
427  * was called in irq context but we have irq tracing off. Since this
428  * can only be modified by current, we can reuse trace_recursion.
429  */
430 	TRACE_IRQ_BIT,
431 };
432 
433 #define trace_recursion_set(bit)	do { (current)->trace_recursion |= (1<<(bit)); } while (0)
434 #define trace_recursion_clear(bit)	do { (current)->trace_recursion &= ~(1<<(bit)); } while (0)
435 #define trace_recursion_test(bit)	((current)->trace_recursion & (1<<(bit)))
436 
437 #define TRACE_CONTEXT_BITS	4
438 
439 #define TRACE_FTRACE_START	TRACE_FTRACE_BIT
440 #define TRACE_FTRACE_MAX	((1 << (TRACE_FTRACE_START + TRACE_CONTEXT_BITS)) - 1)
441 
442 #define TRACE_GLOBAL_START	TRACE_GLOBAL_BIT
443 #define TRACE_GLOBAL_MAX	((1 << (TRACE_GLOBAL_START + TRACE_CONTEXT_BITS)) - 1)
444 
445 #define TRACE_LIST_START	TRACE_INTERNAL_BIT
446 #define TRACE_LIST_MAX		((1 << (TRACE_LIST_START + TRACE_CONTEXT_BITS)) - 1)
447 
448 #define TRACE_CONTEXT_MASK	TRACE_LIST_MAX
449 
450 static __always_inline int trace_get_context_bit(void)
451 {
452 	int bit;
453 
454 	if (in_interrupt()) {
455 		if (in_nmi())
456 			bit = 0;
457 
458 		else if (in_irq())
459 			bit = 1;
460 		else
461 			bit = 2;
462 	} else
463 		bit = 3;
464 
465 	return bit;
466 }
467 
468 static __always_inline int trace_test_and_set_recursion(int start, int max)
469 {
470 	unsigned int val = current->trace_recursion;
471 	int bit;
472 
473 	/* A previous recursion check was made */
474 	if ((val & TRACE_CONTEXT_MASK) > max)
475 		return 0;
476 
477 	bit = trace_get_context_bit() + start;
478 	if (unlikely(val & (1 << bit)))
479 		return -1;
480 
481 	val |= 1 << bit;
482 	current->trace_recursion = val;
483 	barrier();
484 
485 	return bit;
486 }
487 
488 static __always_inline void trace_clear_recursion(int bit)
489 {
490 	unsigned int val = current->trace_recursion;
491 
492 	if (!bit)
493 		return;
494 
495 	bit = 1 << bit;
496 	val &= ~bit;
497 
498 	barrier();
499 	current->trace_recursion = val;
500 }
501 
502 static inline struct ring_buffer_iter *
503 trace_buffer_iter(struct trace_iterator *iter, int cpu)
504 {
505 	if (iter->buffer_iter && iter->buffer_iter[cpu])
506 		return iter->buffer_iter[cpu];
507 	return NULL;
508 }
509 
510 int tracer_init(struct tracer *t, struct trace_array *tr);
511 int tracing_is_enabled(void);
512 void tracing_reset(struct trace_buffer *buf, int cpu);
513 void tracing_reset_online_cpus(struct trace_buffer *buf);
514 void tracing_reset_current(int cpu);
515 void tracing_reset_all_online_cpus(void);
516 int tracing_open_generic(struct inode *inode, struct file *filp);
517 struct dentry *trace_create_file(const char *name,
518 				 umode_t mode,
519 				 struct dentry *parent,
520 				 void *data,
521 				 const struct file_operations *fops);
522 
523 struct dentry *tracing_init_dentry_tr(struct trace_array *tr);
524 struct dentry *tracing_init_dentry(void);
525 
526 struct ring_buffer_event;
527 
528 struct ring_buffer_event *
529 trace_buffer_lock_reserve(struct ring_buffer *buffer,
530 			  int type,
531 			  unsigned long len,
532 			  unsigned long flags,
533 			  int pc);
534 
535 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
536 						struct trace_array_cpu *data);
537 
538 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
539 					  int *ent_cpu, u64 *ent_ts);
540 
541 void __buffer_unlock_commit(struct ring_buffer *buffer,
542 			    struct ring_buffer_event *event);
543 
544 int trace_empty(struct trace_iterator *iter);
545 
546 void *trace_find_next_entry_inc(struct trace_iterator *iter);
547 
548 void trace_init_global_iter(struct trace_iterator *iter);
549 
550 void tracing_iter_reset(struct trace_iterator *iter, int cpu);
551 
552 void poll_wait_pipe(struct trace_iterator *iter);
553 
554 void tracing_sched_switch_trace(struct trace_array *tr,
555 				struct task_struct *prev,
556 				struct task_struct *next,
557 				unsigned long flags, int pc);
558 
559 void tracing_sched_wakeup_trace(struct trace_array *tr,
560 				struct task_struct *wakee,
561 				struct task_struct *cur,
562 				unsigned long flags, int pc);
563 void trace_function(struct trace_array *tr,
564 		    unsigned long ip,
565 		    unsigned long parent_ip,
566 		    unsigned long flags, int pc);
567 void trace_graph_function(struct trace_array *tr,
568 		    unsigned long ip,
569 		    unsigned long parent_ip,
570 		    unsigned long flags, int pc);
571 void trace_latency_header(struct seq_file *m);
572 void trace_default_header(struct seq_file *m);
573 void print_trace_header(struct seq_file *m, struct trace_iterator *iter);
574 int trace_empty(struct trace_iterator *iter);
575 
576 void trace_graph_return(struct ftrace_graph_ret *trace);
577 int trace_graph_entry(struct ftrace_graph_ent *trace);
578 void set_graph_array(struct trace_array *tr);
579 
580 void tracing_start_cmdline_record(void);
581 void tracing_stop_cmdline_record(void);
582 void tracing_sched_switch_assign_trace(struct trace_array *tr);
583 void tracing_stop_sched_switch_record(void);
584 void tracing_start_sched_switch_record(void);
585 int register_tracer(struct tracer *type);
586 int is_tracing_stopped(void);
587 
588 extern cpumask_var_t __read_mostly tracing_buffer_mask;
589 
590 #define for_each_tracing_cpu(cpu)	\
591 	for_each_cpu(cpu, tracing_buffer_mask)
592 
593 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
594 
595 extern unsigned long tracing_thresh;
596 
597 #ifdef CONFIG_TRACER_MAX_TRACE
598 extern unsigned long tracing_max_latency;
599 
600 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
601 void update_max_tr_single(struct trace_array *tr,
602 			  struct task_struct *tsk, int cpu);
603 #endif /* CONFIG_TRACER_MAX_TRACE */
604 
605 #ifdef CONFIG_STACKTRACE
606 void ftrace_trace_stack(struct ring_buffer *buffer, unsigned long flags,
607 			int skip, int pc);
608 
609 void ftrace_trace_stack_regs(struct ring_buffer *buffer, unsigned long flags,
610 			     int skip, int pc, struct pt_regs *regs);
611 
612 void ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags,
613 			    int pc);
614 
615 void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
616 		   int pc);
617 #else
618 static inline void ftrace_trace_stack(struct ring_buffer *buffer,
619 				      unsigned long flags, int skip, int pc)
620 {
621 }
622 
623 static inline void ftrace_trace_stack_regs(struct ring_buffer *buffer,
624 					   unsigned long flags, int skip,
625 					   int pc, struct pt_regs *regs)
626 {
627 }
628 
629 static inline void ftrace_trace_userstack(struct ring_buffer *buffer,
630 					  unsigned long flags, int pc)
631 {
632 }
633 
634 static inline void __trace_stack(struct trace_array *tr, unsigned long flags,
635 				 int skip, int pc)
636 {
637 }
638 #endif /* CONFIG_STACKTRACE */
639 
640 extern cycle_t ftrace_now(int cpu);
641 
642 extern void trace_find_cmdline(int pid, char comm[]);
643 
644 #ifdef CONFIG_DYNAMIC_FTRACE
645 extern unsigned long ftrace_update_tot_cnt;
646 #endif
647 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
648 extern int DYN_FTRACE_TEST_NAME(void);
649 #define DYN_FTRACE_TEST_NAME2 trace_selftest_dynamic_test_func2
650 extern int DYN_FTRACE_TEST_NAME2(void);
651 
652 extern bool ring_buffer_expanded;
653 extern bool tracing_selftest_disabled;
654 DECLARE_PER_CPU(int, ftrace_cpu_disabled);
655 
656 #ifdef CONFIG_FTRACE_STARTUP_TEST
657 extern int trace_selftest_startup_function(struct tracer *trace,
658 					   struct trace_array *tr);
659 extern int trace_selftest_startup_function_graph(struct tracer *trace,
660 						 struct trace_array *tr);
661 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
662 					  struct trace_array *tr);
663 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
664 					     struct trace_array *tr);
665 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
666 						 struct trace_array *tr);
667 extern int trace_selftest_startup_wakeup(struct tracer *trace,
668 					 struct trace_array *tr);
669 extern int trace_selftest_startup_nop(struct tracer *trace,
670 					 struct trace_array *tr);
671 extern int trace_selftest_startup_sched_switch(struct tracer *trace,
672 					       struct trace_array *tr);
673 extern int trace_selftest_startup_branch(struct tracer *trace,
674 					 struct trace_array *tr);
675 /*
676  * Tracer data references selftest functions that only occur
677  * on boot up. These can be __init functions. Thus, when selftests
678  * are enabled, then the tracers need to reference __init functions.
679  */
680 #define __tracer_data		__refdata
681 #else
682 /* Tracers are seldom changed. Optimize when selftests are disabled. */
683 #define __tracer_data		__read_mostly
684 #endif /* CONFIG_FTRACE_STARTUP_TEST */
685 
686 extern void *head_page(struct trace_array_cpu *data);
687 extern unsigned long long ns2usecs(cycle_t nsec);
688 extern int
689 trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
690 extern int
691 trace_vprintk(unsigned long ip, const char *fmt, va_list args);
692 extern int
693 trace_array_vprintk(struct trace_array *tr,
694 		    unsigned long ip, const char *fmt, va_list args);
695 int trace_array_printk(struct trace_array *tr,
696 		       unsigned long ip, const char *fmt, ...);
697 int trace_array_printk_buf(struct ring_buffer *buffer,
698 			   unsigned long ip, const char *fmt, ...);
699 void trace_printk_seq(struct trace_seq *s);
700 enum print_line_t print_trace_line(struct trace_iterator *iter);
701 
702 extern unsigned long trace_flags;
703 
704 /* Standard output formatting function used for function return traces */
705 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
706 
707 /* Flag options */
708 #define TRACE_GRAPH_PRINT_OVERRUN       0x1
709 #define TRACE_GRAPH_PRINT_CPU           0x2
710 #define TRACE_GRAPH_PRINT_OVERHEAD      0x4
711 #define TRACE_GRAPH_PRINT_PROC          0x8
712 #define TRACE_GRAPH_PRINT_DURATION      0x10
713 #define TRACE_GRAPH_PRINT_ABS_TIME      0x20
714 
715 extern enum print_line_t
716 print_graph_function_flags(struct trace_iterator *iter, u32 flags);
717 extern void print_graph_headers_flags(struct seq_file *s, u32 flags);
718 extern enum print_line_t
719 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
720 extern void graph_trace_open(struct trace_iterator *iter);
721 extern void graph_trace_close(struct trace_iterator *iter);
722 extern int __trace_graph_entry(struct trace_array *tr,
723 			       struct ftrace_graph_ent *trace,
724 			       unsigned long flags, int pc);
725 extern void __trace_graph_return(struct trace_array *tr,
726 				 struct ftrace_graph_ret *trace,
727 				 unsigned long flags, int pc);
728 
729 
730 #ifdef CONFIG_DYNAMIC_FTRACE
731 /* TODO: make this variable */
732 #define FTRACE_GRAPH_MAX_FUNCS		32
733 extern int ftrace_graph_filter_enabled;
734 extern int ftrace_graph_count;
735 extern unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS];
736 
737 static inline int ftrace_graph_addr(unsigned long addr)
738 {
739 	int i;
740 
741 	if (!ftrace_graph_filter_enabled)
742 		return 1;
743 
744 	for (i = 0; i < ftrace_graph_count; i++) {
745 		if (addr == ftrace_graph_funcs[i]) {
746 			/*
747 			 * If no irqs are to be traced, but a set_graph_function
748 			 * is set, and called by an interrupt handler, we still
749 			 * want to trace it.
750 			 */
751 			if (in_irq())
752 				trace_recursion_set(TRACE_IRQ_BIT);
753 			else
754 				trace_recursion_clear(TRACE_IRQ_BIT);
755 			return 1;
756 		}
757 	}
758 
759 	return 0;
760 }
761 #else
762 static inline int ftrace_graph_addr(unsigned long addr)
763 {
764 	return 1;
765 }
766 #endif /* CONFIG_DYNAMIC_FTRACE */
767 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
768 static inline enum print_line_t
769 print_graph_function_flags(struct trace_iterator *iter, u32 flags)
770 {
771 	return TRACE_TYPE_UNHANDLED;
772 }
773 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
774 
775 extern struct list_head ftrace_pids;
776 
777 #ifdef CONFIG_FUNCTION_TRACER
778 extern bool ftrace_filter_param __initdata;
779 static inline int ftrace_trace_task(struct task_struct *task)
780 {
781 	if (list_empty(&ftrace_pids))
782 		return 1;
783 
784 	return test_tsk_trace_trace(task);
785 }
786 extern int ftrace_is_dead(void);
787 #else
788 static inline int ftrace_trace_task(struct task_struct *task)
789 {
790 	return 1;
791 }
792 static inline int ftrace_is_dead(void) { return 0; }
793 #endif
794 
795 int ftrace_event_is_function(struct ftrace_event_call *call);
796 
797 /*
798  * struct trace_parser - servers for reading the user input separated by spaces
799  * @cont: set if the input is not complete - no final space char was found
800  * @buffer: holds the parsed user input
801  * @idx: user input length
802  * @size: buffer size
803  */
804 struct trace_parser {
805 	bool		cont;
806 	char		*buffer;
807 	unsigned	idx;
808 	unsigned	size;
809 };
810 
811 static inline bool trace_parser_loaded(struct trace_parser *parser)
812 {
813 	return (parser->idx != 0);
814 }
815 
816 static inline bool trace_parser_cont(struct trace_parser *parser)
817 {
818 	return parser->cont;
819 }
820 
821 static inline void trace_parser_clear(struct trace_parser *parser)
822 {
823 	parser->cont = false;
824 	parser->idx = 0;
825 }
826 
827 extern int trace_parser_get_init(struct trace_parser *parser, int size);
828 extern void trace_parser_put(struct trace_parser *parser);
829 extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
830 	size_t cnt, loff_t *ppos);
831 
832 /*
833  * trace_iterator_flags is an enumeration that defines bit
834  * positions into trace_flags that controls the output.
835  *
836  * NOTE: These bits must match the trace_options array in
837  *       trace.c.
838  */
839 enum trace_iterator_flags {
840 	TRACE_ITER_PRINT_PARENT		= 0x01,
841 	TRACE_ITER_SYM_OFFSET		= 0x02,
842 	TRACE_ITER_SYM_ADDR		= 0x04,
843 	TRACE_ITER_VERBOSE		= 0x08,
844 	TRACE_ITER_RAW			= 0x10,
845 	TRACE_ITER_HEX			= 0x20,
846 	TRACE_ITER_BIN			= 0x40,
847 	TRACE_ITER_BLOCK		= 0x80,
848 	TRACE_ITER_STACKTRACE		= 0x100,
849 	TRACE_ITER_PRINTK		= 0x200,
850 	TRACE_ITER_PREEMPTONLY		= 0x400,
851 	TRACE_ITER_BRANCH		= 0x800,
852 	TRACE_ITER_ANNOTATE		= 0x1000,
853 	TRACE_ITER_USERSTACKTRACE       = 0x2000,
854 	TRACE_ITER_SYM_USEROBJ          = 0x4000,
855 	TRACE_ITER_PRINTK_MSGONLY	= 0x8000,
856 	TRACE_ITER_CONTEXT_INFO		= 0x10000, /* Print pid/cpu/time */
857 	TRACE_ITER_LATENCY_FMT		= 0x20000,
858 	TRACE_ITER_SLEEP_TIME		= 0x40000,
859 	TRACE_ITER_GRAPH_TIME		= 0x80000,
860 	TRACE_ITER_RECORD_CMD		= 0x100000,
861 	TRACE_ITER_OVERWRITE		= 0x200000,
862 	TRACE_ITER_STOP_ON_FREE		= 0x400000,
863 	TRACE_ITER_IRQ_INFO		= 0x800000,
864 	TRACE_ITER_MARKERS		= 0x1000000,
865 	TRACE_ITER_FUNCTION		= 0x2000000,
866 };
867 
868 /*
869  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
870  * control the output of kernel symbols.
871  */
872 #define TRACE_ITER_SYM_MASK \
873 	(TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
874 
875 extern struct tracer nop_trace;
876 
877 #ifdef CONFIG_BRANCH_TRACER
878 extern int enable_branch_tracing(struct trace_array *tr);
879 extern void disable_branch_tracing(void);
880 static inline int trace_branch_enable(struct trace_array *tr)
881 {
882 	if (trace_flags & TRACE_ITER_BRANCH)
883 		return enable_branch_tracing(tr);
884 	return 0;
885 }
886 static inline void trace_branch_disable(void)
887 {
888 	/* due to races, always disable */
889 	disable_branch_tracing();
890 }
891 #else
892 static inline int trace_branch_enable(struct trace_array *tr)
893 {
894 	return 0;
895 }
896 static inline void trace_branch_disable(void)
897 {
898 }
899 #endif /* CONFIG_BRANCH_TRACER */
900 
901 /* set ring buffers to default size if not already done so */
902 int tracing_update_buffers(void);
903 
904 struct ftrace_event_field {
905 	struct list_head	link;
906 	const char		*name;
907 	const char		*type;
908 	int			filter_type;
909 	int			offset;
910 	int			size;
911 	int			is_signed;
912 };
913 
914 struct event_filter {
915 	int			n_preds;	/* Number assigned */
916 	int			a_preds;	/* allocated */
917 	struct filter_pred	*preds;
918 	struct filter_pred	*root;
919 	char			*filter_string;
920 };
921 
922 struct event_subsystem {
923 	struct list_head	list;
924 	const char		*name;
925 	struct event_filter	*filter;
926 	int			ref_count;
927 };
928 
929 struct ftrace_subsystem_dir {
930 	struct list_head		list;
931 	struct event_subsystem		*subsystem;
932 	struct trace_array		*tr;
933 	struct dentry			*entry;
934 	int				ref_count;
935 	int				nr_events;
936 };
937 
938 #define FILTER_PRED_INVALID	((unsigned short)-1)
939 #define FILTER_PRED_IS_RIGHT	(1 << 15)
940 #define FILTER_PRED_FOLD	(1 << 15)
941 
942 /*
943  * The max preds is the size of unsigned short with
944  * two flags at the MSBs. One bit is used for both the IS_RIGHT
945  * and FOLD flags. The other is reserved.
946  *
947  * 2^14 preds is way more than enough.
948  */
949 #define MAX_FILTER_PRED		16384
950 
951 struct filter_pred;
952 struct regex;
953 
954 typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event);
955 
956 typedef int (*regex_match_func)(char *str, struct regex *r, int len);
957 
958 enum regex_type {
959 	MATCH_FULL = 0,
960 	MATCH_FRONT_ONLY,
961 	MATCH_MIDDLE_ONLY,
962 	MATCH_END_ONLY,
963 };
964 
965 struct regex {
966 	char			pattern[MAX_FILTER_STR_VAL];
967 	int			len;
968 	int			field_len;
969 	regex_match_func	match;
970 };
971 
972 struct filter_pred {
973 	filter_pred_fn_t 	fn;
974 	u64 			val;
975 	struct regex		regex;
976 	unsigned short		*ops;
977 	struct ftrace_event_field *field;
978 	int 			offset;
979 	int 			not;
980 	int 			op;
981 	unsigned short		index;
982 	unsigned short		parent;
983 	unsigned short		left;
984 	unsigned short		right;
985 };
986 
987 extern enum regex_type
988 filter_parse_regex(char *buff, int len, char **search, int *not);
989 extern void print_event_filter(struct ftrace_event_call *call,
990 			       struct trace_seq *s);
991 extern int apply_event_filter(struct ftrace_event_call *call,
992 			      char *filter_string);
993 extern int apply_subsystem_event_filter(struct ftrace_subsystem_dir *dir,
994 					char *filter_string);
995 extern void print_subsystem_event_filter(struct event_subsystem *system,
996 					 struct trace_seq *s);
997 extern int filter_assign_type(const char *type);
998 
999 struct ftrace_event_field *
1000 trace_find_event_field(struct ftrace_event_call *call, char *name);
1001 
1002 static inline int
1003 filter_check_discard(struct ftrace_event_call *call, void *rec,
1004 		     struct ring_buffer *buffer,
1005 		     struct ring_buffer_event *event)
1006 {
1007 	if (unlikely(call->flags & TRACE_EVENT_FL_FILTERED) &&
1008 	    !filter_match_preds(call->filter, rec)) {
1009 		ring_buffer_discard_commit(buffer, event);
1010 		return 1;
1011 	}
1012 
1013 	return 0;
1014 }
1015 
1016 extern void trace_event_enable_cmd_record(bool enable);
1017 extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
1018 extern int event_trace_del_tracer(struct trace_array *tr);
1019 
1020 extern struct mutex event_mutex;
1021 extern struct list_head ftrace_events;
1022 
1023 extern const char *__start___trace_bprintk_fmt[];
1024 extern const char *__stop___trace_bprintk_fmt[];
1025 
1026 extern const char *__start___tracepoint_str[];
1027 extern const char *__stop___tracepoint_str[];
1028 
1029 void trace_printk_init_buffers(void);
1030 void trace_printk_start_comm(void);
1031 int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set);
1032 int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled);
1033 
1034 /*
1035  * Normal trace_printk() and friends allocates special buffers
1036  * to do the manipulation, as well as saves the print formats
1037  * into sections to display. But the trace infrastructure wants
1038  * to use these without the added overhead at the price of being
1039  * a bit slower (used mainly for warnings, where we don't care
1040  * about performance). The internal_trace_puts() is for such
1041  * a purpose.
1042  */
1043 #define internal_trace_puts(str) __trace_puts(_THIS_IP_, str, strlen(str))
1044 
1045 #undef FTRACE_ENTRY
1046 #define FTRACE_ENTRY(call, struct_name, id, tstruct, print, filter)	\
1047 	extern struct ftrace_event_call					\
1048 	__attribute__((__aligned__(4))) event_##call;
1049 #undef FTRACE_ENTRY_DUP
1050 #define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print, filter)	\
1051 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print), \
1052 		     filter)
1053 #include "trace_entries.h"
1054 
1055 #if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_FUNCTION_TRACER)
1056 int perf_ftrace_event_register(struct ftrace_event_call *call,
1057 			       enum trace_reg type, void *data);
1058 #else
1059 #define perf_ftrace_event_register NULL
1060 #endif
1061 
1062 #endif /* _LINUX_KERNEL_TRACE_H */
1063