aboutsummaryrefslogtreecommitdiffstats
path: root/include/linux/ftrace.h
blob: 847bb3c48dd09edd49ddc0c42f8a835a5a084639 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
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
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
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
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
#ifndef _LINUX_FTRACE_H
#define _LINUX_FTRACE_H

#include <linux/linkage.h>
#include <linux/fs.h>
#include <linux/ktime.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/module.h>
#include <linux/kallsyms.h>
#include <linux/bitops.h>
#include <linux/sched.h>

#ifdef CONFIG_FUNCTION_TRACER

extern int ftrace_enabled;
extern int
ftrace_enable_sysctl(struct ctl_table *table, int write,
		     struct file *filp, void __user *buffer, size_t *lenp,
		     loff_t *ppos);

typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip);

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

extern int function_trace_stop;

/*
 * 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;

/**
 * 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;
}

/*
 * 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);

#else /* !CONFIG_FUNCTION_TRACER */
# define register_ftrace_function(ops) do { } while (0)
# define unregister_ftrace_function(ops) do { } while (0)
# define clear_ftrace_function(ops) do { } while (0)
static inline void ftrace_kill(void) { }
static inline void ftrace_stop(void) { }
static inline void ftrace_start(void) { }
#endif /* CONFIG_FUNCTION_TRACER */

#ifdef CONFIG_STACK_TRACER
extern int stack_tracer_enabled;
int
stack_trace_sysctl(struct ctl_table *table, int write,
		   struct file *file, void __user *buffer, size_t *lenp,
		   loff_t *ppos);
#endif

struct ftrace_func_command {
	struct list_head	list;
	char			*name;
	int			(*func)(char *func, char *cmd,
					char *params, int enable);
};

#ifdef CONFIG_DYNAMIC_FTRACE
/* asm/ftrace.h must be defined for archs supporting dynamic ftrace */
#include <asm/ftrace.h>

int ftrace_arch_code_modify_prepare(void);
int ftrace_arch_code_modify_post_process(void);

struct seq_file;

struct ftrace_probe_ops {
	void			(*func)(unsigned long ip,
					unsigned long parent_ip,
					void **data);
	int			(*callback)(unsigned long ip, void **data);
	void			(*free)(void **data);
	int			(*print)(struct seq_file *m,
					 unsigned long ip,
					 struct ftrace_probe_ops *ops,
					 void *data);
};

extern int
register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
			      void *data);
extern void
unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
				void *data);
extern void
unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops);
extern void unregister_ftrace_function_probe_all(char *glob);

enum {
	FTRACE_FL_FREE		= (1 << 0),
	FTRACE_FL_FAILED	= (1 << 1),
	FTRACE_FL_FILTER	= (1 << 2),
	FTRACE_FL_ENABLED	= (1 << 3),
	FTRACE_FL_NOTRACE	= (1 << 4),
	FTRACE_FL_CONVERTED	= (1 << 5),
	FTRACE_FL_FROZEN	= (1 << 6),
};

struct dyn_ftrace {
	struct list_head	list;
	unsigned long		ip; /* address of mcount call-site */
	unsigned long		flags;
	struct dyn_arch_ftrace	arch;
};

int ftrace_force_update(void);
void ftrace_set_filter(unsigned char *buf, int len, int reset);

int register_ftrace_command(struct ftrace_func_command *cmd);
int unregister_ftrace_command(struct ftrace_func_command *cmd);

/* defined in arch */
extern int ftrace_ip_converted(unsigned long ip);
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);

#ifndef FTRACE_ADDR
#define FTRACE_ADDR ((unsigned long)ftrace_caller)
#endif
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
extern void ftrace_graph_caller(void);
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; }
#endif

/**
 * ftrace_make_nop - convert code into nop
 * @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);

/**
 * 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
 *
 * 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 nop
 *
 * 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_call(struct dyn_ftrace *rec, unsigned long addr);


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

extern int skip_trace(unsigned long ip);

extern void ftrace_release(void *start, unsigned long size);

extern void ftrace_disable_daemon(void);
extern void ftrace_enable_daemon(void);
#else
# define skip_trace(ip)				({ 0; })
# define ftrace_force_update()			({ 0; })
# define ftrace_set_filter(buf, len, reset)	do { } while (0)
# define ftrace_disable_daemon()		do { } while (0)
# define ftrace_enable_daemon()			do { } while (0)
static inline void ftrace_release(void *start, unsigned long size) { }
static inline int register_ftrace_command(struct ftrace_func_command *cmd)
{
	return -EINVAL;
}
static inline int unregister_ftrace_command(char *cmd_name)
{
	return -EINVAL;
}
#endif /* CONFIG_DYNAMIC_FTRACE */

/* totally disable ftrace - can not re-enable after this */
void ftrace_kill(void);

static inline void tracer_disable(void)
{
#ifdef CONFIG_FUNCTION_TRACER
	ftrace_enabled = 0;
#endif
}

/*
 * Ftrace disable/restore without lock. Some synchronization mechanism
 * must be used to prevent ftrace_enabled to be changed between
 * disable/restore.
 */
static inline int __ftrace_enabled_save(void)
{
#ifdef CONFIG_FUNCTION_TRACER
	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)
{
#ifdef CONFIG_FUNCTION_TRACER
	ftrace_enabled = enabled;
#endif
}

#ifdef CONFIG_FRAME_POINTER
/* TODO: need to fix this for ARM */
# 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

#ifdef CONFIG_IRQSOFF_TRACER
  extern void time_hardirqs_on(unsigned long a0, unsigned long a1);
  extern void time_hardirqs_off(unsigned long a0, unsigned long a1);
#else
# define time_hardirqs_on(a0, a1)		do { } while (0)
# define time_hardirqs_off(a0, a1)		do { } while (0)
#endif

#ifdef CONFIG_PREEMPT_TRACER
  extern void trace_preempt_on(unsigned long a0, unsigned long a1);
  extern void trace_preempt_off(unsigned long a0, unsigned long a1);
#else
# define trace_preempt_on(a0, a1)		do { } while (0)
# define trace_preempt_off(a0, a1)		do { } while (0)
#endif

#ifdef CONFIG_TRACING
extern int ftrace_dump_on_oops;

extern void tracing_start(void);
extern void tracing_stop(void);
extern void ftrace_off_permanent(void);

extern void
ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3);

/**
 * ftrace_printk - printf formatting in the ftrace buffer
 * @fmt: the printf format for printing
 *
 * Note: __ftrace_printk is an internal function for ftrace_printk and
 *       the @ip is passed in via the ftrace_printk macro.
 *
 * This function allows a kernel developer to debug fast path sections
 * that printk is not appropriate for. By scattering in various
 * printk like tracing in the code, a developer can quickly see
 * where problems are occurring.
 *
 * This is intended as a debugging tool for the developer only.
 * Please refrain from leaving ftrace_printks scattered around in
 * your code.
 */
# define ftrace_printk(fmt...) __ftrace_printk(_THIS_IP_, fmt)
extern int
__ftrace_printk(unsigned long ip, const char *fmt, ...)
	__attribute__ ((format (printf, 2, 3)));
# define ftrace_vprintk(fmt, ap) __ftrace_printk(_THIS_IP_, fmt, ap)
extern int
__ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);
extern void ftrace_dump(void);
#else
static inline void
ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3) { }
static inline int
ftrace_printk(const char *fmt, ...) __attribute__ ((format (printf, 1, 2)));

static inline void tracing_start(void) { }
static inline void tracing_stop(void) { }
static inline void ftrace_off_permanent(void) { }
static inline int
ftrace_printk(const char *fmt, ...)
{
	return 0;
}
static inline int
ftrace_vprintk(const char *fmt, va_list ap)
{
	return 0;
}
static inline void ftrace_dump(void) { }
#endif

#ifdef CONFIG_FTRACE_MCOUNT_RECORD
extern void ftrace_init(void);
extern void ftrace_init_module(struct module *mod,
			       unsigned long *start, unsigned long *end);
#else
static inline void ftrace_init(void) { }
static inline void
ftrace_init_module(struct module *mod,
		   unsigned long *start, unsigned long *end) { }
#endif

/*
 * Structure that defines an entry function trace.
 */
struct ftrace_graph_ent {
	unsigned long func; /* Current function */
	int depth;
};

/*
 * Structure that defines a return function trace.
 */
struct ftrace_graph_ret {
	unsigned long func; /* Current function */
	unsigned long long calltime;
	unsigned long long rettime;
	/* Number of functions that overran the depth limit for current task */
	unsigned long overrun;
	int depth;
};

#ifdef CONFIG_FUNCTION_GRAPH_TRACER

/*
 * 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;
};

/*
 * 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
ftrace_push_return_trace(unsigned long ret, unsigned long long time,
			 unsigned long func, int *depth);
extern void
ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret);

/*
 * 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

/*
 * 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[];

#define FTRACE_RETFUNC_DEPTH 50
#define FTRACE_RETSTACK_ALLOC_SIZE 32
/* 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 */

extern int register_ftrace_graph(trace_func_graph_ret_t retfunc,
				trace_func_graph_ent_t entryfunc);

extern void ftrace_graph_stop(void);

/* The current handlers in use */
extern trace_func_graph_ret_t ftrace_graph_return;
extern trace_func_graph_ent_t ftrace_graph_entry;

extern void unregister_ftrace_graph(void);

extern void ftrace_graph_init_task(struct task_struct *t);
extern void ftrace_graph_exit_task(struct task_struct *t);

static inline int task_curr_ret_stack(struct task_struct *t)
{
	return t->curr_ret_stack;
}

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);
}
#else

#define __notrace_funcgraph
#define __irq_entry

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

static inline int task_curr_ret_stack(struct task_struct *tsk)
{
	return -1;
}

static inline void pause_graph_tracing(void) { }
static inline void unpause_graph_tracing(void) { }
#endif

#ifdef CONFIG_TRACING
#include <linux/sched.h>

/* 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;
}

#endif /* CONFIG_TRACING */


#ifdef CONFIG_HW_BRANCH_TRACER

void trace_hw_branch(u64 from, u64 to);
void trace_hw_branch_oops(void);

#else /* CONFIG_HW_BRANCH_TRACER */

static inline void trace_hw_branch(u64 from, u64 to) {}
static inline void trace_hw_branch_oops(void) {}

#endif /* CONFIG_HW_BRANCH_TRACER */

#endif /* _LINUX_FTRACE_H */