ftrace.h 14.4 KB
Newer Older
1
2
3
4
5
/*
 * Ftrace header.  For implementation details beyond the random comments
 * scattered below, see: Documentation/trace/ftrace-design.txt
 */

6
7
8
#ifndef _LINUX_FTRACE_H
#define _LINUX_FTRACE_H

9
#include <linux/trace_clock.h>
10
#include <linux/kallsyms.h>
11
#include <linux/linkage.h>
12
#include <linux/bitops.h>
13
14
#include <linux/module.h>
#include <linux/ktime.h>
15
#include <linux/sched.h>
16
17
18
#include <linux/types.h>
#include <linux/init.h>
#include <linux/fs.h>
19

20
21
#include <asm/ftrace.h>

22
#ifdef CONFIG_FUNCTION_TRACER
Ingo Molnar's avatar
Ingo Molnar committed
23

24
25
26
extern int ftrace_enabled;
extern int
ftrace_enable_sysctl(struct ctl_table *table, int write,
27
		     void __user *buffer, size_t *lenp,
28
29
		     loff_t *ppos);

30
31
32
33
34
35
36
typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip);

struct ftrace_ops {
	ftrace_func_t	  func;
	struct ftrace_ops *next;
};

37
38
extern int function_trace_stop;

39
40
41
42
43
44
45
46
47
48
49
/*
 * Type of the current tracing.
 */
enum ftrace_tracing_type_t {
	FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */
	FTRACE_TYPE_RETURN,	/* Hook the return of the function */
};

/* Current tracing type, default is FTRACE_TYPE_ENTER */
extern enum ftrace_tracing_type_t ftrace_tracing_type;

50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
/**
 * ftrace_stop - stop function tracer.
 *
 * A quick way to stop the function tracer. Note this an on off switch,
 * it is not something that is recursive like preempt_disable.
 * This does not disable the calling of mcount, it only stops the
 * calling of functions from mcount.
 */
static inline void ftrace_stop(void)
{
	function_trace_stop = 1;
}

/**
 * ftrace_start - start the function tracer.
 *
 * This function is the inverse of ftrace_stop. This does not enable
 * the function tracing if the function tracer is disabled. This only
 * sets the function tracer flag to continue calling the functions
 * from mcount.
 */
static inline void ftrace_start(void)
{
	function_trace_stop = 0;
}

76
77
78
79
80
81
82
83
84
85
86
87
88
/*
 * The ftrace_ops must be a static and should also
 * be read_mostly.  These functions do modify read_mostly variables
 * so use them sparely. Never free an ftrace_op or modify the
 * next pointer after it has been registered. Even after unregistering
 * it, the next pointer may still be used internally.
 */
int register_ftrace_function(struct ftrace_ops *ops);
int unregister_ftrace_function(struct ftrace_ops *ops);
void clear_ftrace_function(void);

extern void ftrace_stub(unsigned long a0, unsigned long a1);

89
#else /* !CONFIG_FUNCTION_TRACER */
90
91
92
93
94
95
96
/*
 * (un)register_ftrace_function must be a macro since the ops parameter
 * must not be evaluated.
 */
#define register_ftrace_function(ops) ({ 0; })
#define unregister_ftrace_function(ops) ({ 0; })
static inline void clear_ftrace_function(void) { }
97
static inline void ftrace_kill(void) { }
98
99
static inline void ftrace_stop(void) { }
static inline void ftrace_start(void) { }
100
#endif /* CONFIG_FUNCTION_TRACER */
101

102
103
104
105
#ifdef CONFIG_STACK_TRACER
extern int stack_tracer_enabled;
int
stack_trace_sysctl(struct ctl_table *table, int write,
106
		   void __user *buffer, size_t *lenp,
107
108
109
		   loff_t *ppos);
#endif

110
111
112
113
114
115
116
struct ftrace_func_command {
	struct list_head	list;
	char			*name;
	int			(*func)(char *func, char *cmd,
					char *params, int enable);
};

117
#ifdef CONFIG_DYNAMIC_FTRACE
118

119
120
121
int ftrace_arch_code_modify_prepare(void);
int ftrace_arch_code_modify_post_process(void);

122
123
struct seq_file;

124
struct ftrace_probe_ops {
125
126
127
128
129
	void			(*func)(unsigned long ip,
					unsigned long parent_ip,
					void **data);
	int			(*callback)(unsigned long ip, void **data);
	void			(*free)(void **data);
130
131
	int			(*print)(struct seq_file *m,
					 unsigned long ip,
132
					 struct ftrace_probe_ops *ops,
133
					 void *data);
134
135
136
};

extern int
137
register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
138
139
			      void *data);
extern void
140
unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
141
142
				void *data);
extern void
143
144
unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops);
extern void unregister_ftrace_function_probe_all(char *glob);
145

146
147
extern int ftrace_text_reserved(void *start, void *end);

148
enum {
149
150
151
152
	FTRACE_FL_FREE		= (1 << 0),
	FTRACE_FL_FAILED	= (1 << 1),
	FTRACE_FL_FILTER	= (1 << 2),
	FTRACE_FL_ENABLED	= (1 << 3),
153
	FTRACE_FL_NOTRACE	= (1 << 4),
154
	FTRACE_FL_CONVERTED	= (1 << 5),
155
156
};

157
struct dyn_ftrace {
158
159
160
161
162
163
164
165
166
	union {
		unsigned long		ip; /* address of mcount call-site */
		struct dyn_ftrace	*freelist;
	};
	union {
		unsigned long		flags;
		struct dyn_ftrace	*newlist;
	};
	struct dyn_arch_ftrace		arch;
167
168
};

Steven Rostedt's avatar
Steven Rostedt committed
169
int ftrace_force_update(void);
170
void ftrace_set_filter(unsigned char *buf, int len, int reset);
Steven Rostedt's avatar
Steven Rostedt committed
171

172
173
174
int register_ftrace_command(struct ftrace_func_command *cmd);
int unregister_ftrace_command(struct ftrace_func_command *cmd);

175
/* defined in arch */
176
extern int ftrace_ip_converted(unsigned long ip);
177
178
179
180
181
extern int ftrace_dyn_arch_init(void *data);
extern int ftrace_update_ftrace_func(ftrace_func_t func);
extern void ftrace_caller(void);
extern void ftrace_call(void);
extern void mcount_call(void);
182
183
184
185

#ifndef FTRACE_ADDR
#define FTRACE_ADDR ((unsigned long)ftrace_caller)
#endif
186
187
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
extern void ftrace_graph_caller(void);
188
189
190
191
192
extern int ftrace_enable_ftrace_graph_caller(void);
extern int ftrace_disable_ftrace_graph_caller(void);
#else
static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; }
static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; }
193
#endif
194

195
/**
196
 * ftrace_make_nop - convert code into nop
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
 * @mod: module structure if called by module load initialization
 * @rec: the mcount call site record
 * @addr: the address that the call site should be calling
 *
 * This is a very sensitive operation and great care needs
 * to be taken by the arch.  The operation should carefully
 * read the location, check to see if what is read is indeed
 * what we expect it to be, and then on success of the compare,
 * it should write to the location.
 *
 * The code segment at @rec->ip should be a caller to @addr
 *
 * Return must be:
 *  0 on success
 *  -EFAULT on error reading the location
 *  -EINVAL on a failed compare of the contents
 *  -EPERM  on error writing to the location
 * Any other value will be considered a failure.
 */
extern int ftrace_make_nop(struct module *mod,
			   struct dyn_ftrace *rec, unsigned long addr);
218

219
/**
220
221
222
 * ftrace_make_call - convert a nop call site into a call to addr
 * @rec: the mcount call site record
 * @addr: the address that the call site should call
223
224
225
226
227
228
229
 *
 * This is a very sensitive operation and great care needs
 * to be taken by the arch.  The operation should carefully
 * read the location, check to see if what is read is indeed
 * what we expect it to be, and then on success of the compare,
 * it should write to the location.
 *
230
231
 * The code segment at @rec->ip should be a nop
 *
232
233
234
235
236
237
238
 * Return must be:
 *  0 on success
 *  -EFAULT on error reading the location
 *  -EINVAL on a failed compare of the contents
 *  -EPERM  on error writing to the location
 * Any other value will be considered a failure.
 */
239
240
241
242
extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr);

/* May be defined in arch */
extern int ftrace_arch_read_dyn_info(char *buf, int size);
243

244
245
extern int skip_trace(unsigned long ip);

246
247
extern void ftrace_disable_daemon(void);
extern void ftrace_enable_daemon(void);
Steven Rostedt's avatar
Steven Rostedt committed
248
#else
249
250
251
252
253
254
255
static inline int skip_trace(unsigned long ip) { return 0; }
static inline int ftrace_force_update(void) { return 0; }
static inline void ftrace_set_filter(unsigned char *buf, int len, int reset)
{
}
static inline void ftrace_disable_daemon(void) { }
static inline void ftrace_enable_daemon(void) { }
256
static inline void ftrace_release_mod(struct module *mod) {}
257
258
static inline int register_ftrace_command(struct ftrace_func_command *cmd)
{
259
	return -EINVAL;
260
261
262
}
static inline int unregister_ftrace_command(char *cmd_name)
{
263
	return -EINVAL;
264
}
265
266
267
268
static inline int ftrace_text_reserved(void *start, void *end)
{
	return 0;
}
269
#endif /* CONFIG_DYNAMIC_FTRACE */
270

Ingo Molnar's avatar
Ingo Molnar committed
271
272
273
/* totally disable ftrace - can not re-enable after this */
void ftrace_kill(void);

Ingo Molnar's avatar
Ingo Molnar committed
274
275
static inline void tracer_disable(void)
{
276
#ifdef CONFIG_FUNCTION_TRACER
Ingo Molnar's avatar
Ingo Molnar committed
277
278
279
280
	ftrace_enabled = 0;
#endif
}

281
282
/*
 * Ftrace disable/restore without lock. Some synchronization mechanism
283
 * must be used to prevent ftrace_enabled to be changed between
284
285
 * disable/restore.
 */
286
287
static inline int __ftrace_enabled_save(void)
{
288
#ifdef CONFIG_FUNCTION_TRACER
289
290
291
292
293
294
295
296
297
298
	int saved_ftrace_enabled = ftrace_enabled;
	ftrace_enabled = 0;
	return saved_ftrace_enabled;
#else
	return 0;
#endif
}

static inline void __ftrace_enabled_restore(int enabled)
{
299
#ifdef CONFIG_FUNCTION_TRACER
300
301
302
303
	ftrace_enabled = enabled;
#endif
}

304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
#ifndef HAVE_ARCH_CALLER_ADDR
# ifdef CONFIG_FRAME_POINTER
#  define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
#  define CALLER_ADDR1 ((unsigned long)__builtin_return_address(1))
#  define CALLER_ADDR2 ((unsigned long)__builtin_return_address(2))
#  define CALLER_ADDR3 ((unsigned long)__builtin_return_address(3))
#  define CALLER_ADDR4 ((unsigned long)__builtin_return_address(4))
#  define CALLER_ADDR5 ((unsigned long)__builtin_return_address(5))
#  define CALLER_ADDR6 ((unsigned long)__builtin_return_address(6))
# else
#  define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
#  define CALLER_ADDR1 0UL
#  define CALLER_ADDR2 0UL
#  define CALLER_ADDR3 0UL
#  define CALLER_ADDR4 0UL
#  define CALLER_ADDR5 0UL
#  define CALLER_ADDR6 0UL
# endif
#endif /* ifndef HAVE_ARCH_CALLER_ADDR */
323

324
#ifdef CONFIG_IRQSOFF_TRACER
Ingo Molnar's avatar
Ingo Molnar committed
325
326
  extern void time_hardirqs_on(unsigned long a0, unsigned long a1);
  extern void time_hardirqs_off(unsigned long a0, unsigned long a1);
327
#else
328
329
  static inline void time_hardirqs_on(unsigned long a0, unsigned long a1) { }
  static inline void time_hardirqs_off(unsigned long a0, unsigned long a1) { }
330
331
#endif

332
#ifdef CONFIG_PREEMPT_TRACER
Ingo Molnar's avatar
Ingo Molnar committed
333
334
  extern void trace_preempt_on(unsigned long a0, unsigned long a1);
  extern void trace_preempt_off(unsigned long a0, unsigned long a1);
335
#else
336
337
  static inline void trace_preempt_on(unsigned long a0, unsigned long a1) { }
  static inline void trace_preempt_off(unsigned long a0, unsigned long a1) { }
338
339
#endif

340
341
342
343
344
345
#ifdef CONFIG_FTRACE_MCOUNT_RECORD
extern void ftrace_init(void);
#else
static inline void ftrace_init(void) { }
#endif

346
347
348
349
350
351
352
/*
 * Structure that defines an entry function trace.
 */
struct ftrace_graph_ent {
	unsigned long func; /* Current function */
	int depth;
};
353

354
355
356
/*
 * Structure that defines a return function trace.
 */
357
struct ftrace_graph_ret {
358
359
360
	unsigned long func; /* Current function */
	unsigned long long calltime;
	unsigned long long rettime;
361
362
	/* Number of functions that overran the depth limit for current task */
	unsigned long overrun;
363
	int depth;
364
365
};

366
367
368
369
/* Type of the callback handlers for tracing function graph*/
typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */
typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */

370
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
371

372
/* for init task */
373
#define INIT_FTRACE_GRAPH		.ret_stack = NULL,
374

375
376
377
378
379
380
381
382
383
/*
 * Stack of return addresses for functions
 * of a thread.
 * Used in struct thread_info
 */
struct ftrace_ret_stack {
	unsigned long ret;
	unsigned long func;
	unsigned long long calltime;
384
	unsigned long long subtime;
385
	unsigned long fp;
386
387
388
389
390
391
392
393
394
395
};

/*
 * Primary handler of a function return.
 * It relays on ftrace_return_to_handler.
 * Defined in entry_32/64.S
 */
extern void return_to_handler(void);

extern int
396
397
ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
			 unsigned long frame_pointer);
398

399
400
401
402
403
404
405
/*
 * Sometimes we don't want to trace a function with the function
 * graph tracer but we want them to keep traced by the usual function
 * tracer if the function graph tracer is not configured.
 */
#define __notrace_funcgraph		notrace

406
407
408
409
410
411
412
413
414
415
/*
 * We want to which function is an entrypoint of a hardirq.
 * That will help us to put a signal on output.
 */
#define __irq_entry		 __attribute__((__section__(".irqentry.text")))

/* Limits of hardirq entrypoints */
extern char __irqentry_text_start[];
extern char __irqentry_text_end[];

416
417
#define FTRACE_RETFUNC_DEPTH 50
#define FTRACE_RETSTACK_ALLOC_SIZE 32
418
419
420
extern int register_ftrace_graph(trace_func_graph_ret_t retfunc,
				trace_func_graph_ent_t entryfunc);

421
422
extern void ftrace_graph_stop(void);

423
424
425
/* The current handlers in use */
extern trace_func_graph_ret_t ftrace_graph_return;
extern trace_func_graph_ent_t ftrace_graph_entry;
426

427
extern void unregister_ftrace_graph(void);
428

429
430
extern void ftrace_graph_init_task(struct task_struct *t);
extern void ftrace_graph_exit_task(struct task_struct *t);
431
432
433
434
435

static inline int task_curr_ret_stack(struct task_struct *t)
{
	return t->curr_ret_stack;
}
436
437
438
439
440
441
442
443
444
445

static inline void pause_graph_tracing(void)
{
	atomic_inc(&current->tracing_graph_pause);
}

static inline void unpause_graph_tracing(void)
{
	atomic_dec(&current->tracing_graph_pause);
}
446
#else /* !CONFIG_FUNCTION_GRAPH_TRACER */
447
448

#define __notrace_funcgraph
449
#define __irq_entry
450
#define INIT_FTRACE_GRAPH
451

452
453
static inline void ftrace_graph_init_task(struct task_struct *t) { }
static inline void ftrace_graph_exit_task(struct task_struct *t) { }
454

455
456
457
458
459
460
461
static inline int register_ftrace_graph(trace_func_graph_ret_t retfunc,
			  trace_func_graph_ent_t entryfunc)
{
	return -1;
}
static inline void unregister_ftrace_graph(void) { }

462
463
464
465
static inline int task_curr_ret_stack(struct task_struct *tsk)
{
	return -1;
}
466
467
468

static inline void pause_graph_tracing(void) { }
static inline void unpause_graph_tracing(void) { }
469
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
470

471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
#ifdef CONFIG_TRACING

/* flags for current->trace */
enum {
	TSK_TRACE_FL_TRACE_BIT	= 0,
	TSK_TRACE_FL_GRAPH_BIT	= 1,
};
enum {
	TSK_TRACE_FL_TRACE	= 1 << TSK_TRACE_FL_TRACE_BIT,
	TSK_TRACE_FL_GRAPH	= 1 << TSK_TRACE_FL_GRAPH_BIT,
};

static inline void set_tsk_trace_trace(struct task_struct *tsk)
{
	set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
}

static inline void clear_tsk_trace_trace(struct task_struct *tsk)
{
	clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
}

static inline int test_tsk_trace_trace(struct task_struct *tsk)
{
	return tsk->trace & TSK_TRACE_FL_TRACE;
}

static inline void set_tsk_trace_graph(struct task_struct *tsk)
{
	set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
}

static inline void clear_tsk_trace_graph(struct task_struct *tsk)
{
	clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
}

static inline int test_tsk_trace_graph(struct task_struct *tsk)
{
	return tsk->trace & TSK_TRACE_FL_GRAPH;
}

513
514
515
enum ftrace_dump_mode;

extern enum ftrace_dump_mode ftrace_dump_on_oops;
516

517
518
519
520
#ifdef CONFIG_PREEMPT
#define INIT_TRACE_RECURSION		.trace_recursion = 0,
#endif

521
522
#endif /* CONFIG_TRACING */

523
524
525
#ifndef INIT_TRACE_RECURSION
#define INIT_TRACE_RECURSION
#endif
526

527
528
529
530
531
532
#ifdef CONFIG_FTRACE_SYSCALLS

unsigned long arch_syscall_addr(int nr);

#endif /* CONFIG_FTRACE_SYSCALLS */

533
#endif /* _LINUX_FTRACE_H */