summaryrefslogtreecommitdiffstats
path: root/include/linux/ftrace.h
blob: 9c5bc6be2b091274b37b14046f03ebf3db70c194 (plain)
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
#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>

#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;
};

/*
 * 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) { }
#endif /* CONFIG_FUNCTION_TRACER */

#ifdef CONFIG_DYNAMIC_FTRACE

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;
};

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

/* defined in arch */
extern int ftrace_ip_converted(unsigned long ip);
extern unsigned char *ftrace_nop_replace(void);
extern unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr);
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);

/**
 * ftrace_modify_code - modify code segment
 * @ip: the address of the code segment
 * @old_code: the contents of what is expected to be there
 * @new_code: the code to patch in
 *
 * 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.
 *
 * 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_modify_code(unsigned long ip, unsigned char *old_code,
			      unsigned char *new_code);

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) { }
#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 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)));
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, 0)));

static inline int
ftrace_printk(const char *fmt, ...)
{
	return 0;
}
static inline void ftrace_dump(void) { }
#endif

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


struct boot_trace {
	pid_t			caller;
	char			func[KSYM_SYMBOL_LEN];
	int			result;
	unsigned long long	duration;		/* usecs */
	ktime_t			calltime;
	ktime_t			rettime;
};

#ifdef CONFIG_BOOT_TRACER
extern void trace_boot(struct boot_trace *it, initcall_t fn);
extern void start_boot_trace(void);
extern void stop_boot_trace(void);
#else
static inline void trace_boot(struct boot_trace *it, initcall_t fn) { }
static inline void start_boot_trace(void) { }
static inline void stop_boot_trace(void) { }
#endif



#endif /* _LINUX_FTRACE_H */
OpenPOWER on IntegriCloud