ftrace.h 9.54 KB
Newer Older
1
2
3
4
#ifndef _LINUX_FTRACE_H
#define _LINUX_FTRACE_H

#include <linux/linkage.h>
5
#include <linux/fs.h>
6
#include <linux/ktime.h>
7
8
#include <linux/init.h>
#include <linux/types.h>
9
#include <linux/kallsyms.h>
10

11
#ifdef CONFIG_FUNCTION_TRACER
Ingo Molnar's avatar
Ingo Molnar committed
12

13
14
15
16
17
18
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);

19
20
21
22
23
24
25
typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip);

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

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
extern int function_trace_stop;

/**
 * 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;
}

54
55
56
57
58
59
60
61
62
63
64
65
66
/*
 * 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);

67
#else /* !CONFIG_FUNCTION_TRACER */
68
69
70
# define register_ftrace_function(ops) do { } while (0)
# define unregister_ftrace_function(ops) do { } while (0)
# define clear_ftrace_function(ops) do { } while (0)
71
static inline void ftrace_kill(void) { }
72
73
static inline void ftrace_stop(void) { }
static inline void ftrace_start(void) { }
74
#endif /* CONFIG_FUNCTION_TRACER */
75

76
#ifdef CONFIG_DYNAMIC_FTRACE
77
78
79
/* asm/ftrace.h must be defined for archs supporting dynamic ftrace */
#include <asm/ftrace.h>

80
enum {
81
82
83
84
	FTRACE_FL_FREE		= (1 << 0),
	FTRACE_FL_FAILED	= (1 << 1),
	FTRACE_FL_FILTER	= (1 << 2),
	FTRACE_FL_ENABLED	= (1 << 3),
85
	FTRACE_FL_NOTRACE	= (1 << 4),
86
	FTRACE_FL_CONVERTED	= (1 << 5),
87
	FTRACE_FL_FROZEN	= (1 << 6),
88
89
};

90
struct dyn_ftrace {
Steven Rostedt's avatar
Steven Rostedt committed
91
92
93
	struct list_head	list;
	unsigned long		ip; /* address of mcount call-site */
	unsigned long		flags;
94
	struct dyn_arch_ftrace	arch;
95
96
};

Steven Rostedt's avatar
Steven Rostedt committed
97
int ftrace_force_update(void);
98
void ftrace_set_filter(unsigned char *buf, int len, int reset);
Steven Rostedt's avatar
Steven Rostedt committed
99

100
/* defined in arch */
101
extern int ftrace_ip_converted(unsigned long ip);
102
103
104
105
106
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);
107

108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
/**
 * ftrace_make_nop - convert code into top
 * @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);
131

132
/**
133
134
135
 * 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
136
137
138
139
140
141
142
 *
 * 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.
 *
143
144
 * The code segment at @rec->ip should be a nop
 *
145
146
147
148
149
150
151
 * 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.
 */
152
153
154
155
156
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);
157

158
159
extern int skip_trace(unsigned long ip);

160
161
162
163
extern void ftrace_release(void *start, unsigned long size);

extern void ftrace_disable_daemon(void);
extern void ftrace_enable_daemon(void);
Steven Rostedt's avatar
Steven Rostedt committed
164
#else
165
# define skip_trace(ip)				({ 0; })
Ingo Molnar's avatar
Ingo Molnar committed
166
167
# define ftrace_force_update()			({ 0; })
# define ftrace_set_filter(buf, len, reset)	do { } while (0)
168
169
# define ftrace_disable_daemon()		do { } while (0)
# define ftrace_enable_daemon()			do { } while (0)
170
static inline void ftrace_release(void *start, unsigned long size) { }
171
#endif /* CONFIG_DYNAMIC_FTRACE */
172

Ingo Molnar's avatar
Ingo Molnar committed
173
174
175
/* totally disable ftrace - can not re-enable after this */
void ftrace_kill(void);

Ingo Molnar's avatar
Ingo Molnar committed
176
177
static inline void tracer_disable(void)
{
178
#ifdef CONFIG_FUNCTION_TRACER
Ingo Molnar's avatar
Ingo Molnar committed
179
180
181
182
	ftrace_enabled = 0;
#endif
}

183
184
/*
 * Ftrace disable/restore without lock. Some synchronization mechanism
185
 * must be used to prevent ftrace_enabled to be changed between
186
187
 * disable/restore.
 */
188
189
static inline int __ftrace_enabled_save(void)
{
190
#ifdef CONFIG_FUNCTION_TRACER
191
192
193
194
195
196
197
198
199
200
	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)
{
201
#ifdef CONFIG_FUNCTION_TRACER
202
203
204
205
	ftrace_enabled = enabled;
#endif
}

206
207
208
209
210
211
212
213
#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))
Ingo Molnar's avatar
Ingo Molnar committed
214
# define CALLER_ADDR6 ((unsigned long)__builtin_return_address(6))
215
216
217
218
219
220
221
#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
Ingo Molnar's avatar
Ingo Molnar committed
222
# define CALLER_ADDR6 0UL
223
224
#endif

225
#ifdef CONFIG_IRQSOFF_TRACER
Ingo Molnar's avatar
Ingo Molnar committed
226
227
  extern void time_hardirqs_on(unsigned long a0, unsigned long a1);
  extern void time_hardirqs_off(unsigned long a0, unsigned long a1);
228
229
230
231
232
#else
# define time_hardirqs_on(a0, a1)		do { } while (0)
# define time_hardirqs_off(a0, a1)		do { } while (0)
#endif

233
#ifdef CONFIG_PREEMPT_TRACER
Ingo Molnar's avatar
Ingo Molnar committed
234
235
  extern void trace_preempt_on(unsigned long a0, unsigned long a1);
  extern void trace_preempt_off(unsigned long a0, unsigned long a1);
236
237
238
239
240
#else
# define trace_preempt_on(a0, a1)		do { } while (0)
# define trace_preempt_off(a0, a1)		do { } while (0)
#endif

Ingo Molnar's avatar
Ingo Molnar committed
241
#ifdef CONFIG_TRACING
242
243
extern int ftrace_dump_on_oops;

244
245
246
extern void tracing_start(void);
extern void tracing_stop(void);

Ingo Molnar's avatar
Ingo Molnar committed
247
248
extern void
ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3);
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266

/**
 * 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)
267
268
269
extern int
__ftrace_printk(unsigned long ip, const char *fmt, ...)
	__attribute__ ((format (printf, 2, 3)));
270
extern void ftrace_dump(void);
Ingo Molnar's avatar
Ingo Molnar committed
271
272
273
#else
static inline void
ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3) { }
274
static inline int
Ingo Molnar's avatar
Ingo Molnar committed
275
276
ftrace_printk(const char *fmt, ...) __attribute__ ((format (printf, 1, 0)));

277
278
static inline void tracing_start(void) { }
static inline void tracing_stop(void) { }
Ingo Molnar's avatar
Ingo Molnar committed
279
280
static inline int
ftrace_printk(const char *fmt, ...)
281
282
283
{
	return 0;
}
284
static inline void ftrace_dump(void) { }
Ingo Molnar's avatar
Ingo Molnar committed
285
286
#endif

287
288
#ifdef CONFIG_FTRACE_MCOUNT_RECORD
extern void ftrace_init(void);
289
290
extern void ftrace_init_module(struct module *mod,
			       unsigned long *start, unsigned long *end);
291
292
#else
static inline void ftrace_init(void) { }
293
static inline void
294
295
ftrace_init_module(struct module *mod,
		   unsigned long *start, unsigned long *end) { }
296
297
#endif

298

299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
/*
 * Structure that defines a return function trace.
 */
struct ftrace_retfunc {
	unsigned long ret; /* Return address */
	unsigned long func; /* Current function */
	unsigned long long calltime;
	unsigned long long rettime;
};

#ifdef CONFIG_FUNCTION_RET_TRACER
/* Type of a callback handler of tracing return function */
typedef void (*trace_function_return_t)(struct ftrace_retfunc *);

extern void register_ftrace_return(trace_function_return_t func);
/* The current handler in use */
extern trace_function_return_t ftrace_function_return;
extern void unregister_ftrace_return(void);
#endif

319
#endif /* _LINUX_FTRACE_H */