Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
1#ifndef _LINUX_FTRACE_H
2#define _LINUX_FTRACE_H
3
4#include <linux/linkage.h>
5#include <linux/fs.h>
6#include <linux/ktime.h>
7#include <linux/init.h>
8#include <linux/types.h>
9#include <linux/kallsyms.h>
10
11#ifdef CONFIG_FUNCTION_TRACER
12
13extern int ftrace_enabled;
14extern int
15ftrace_enable_sysctl(struct ctl_table *table, int write,
16 struct file *filp, void __user *buffer, size_t *lenp,
17 loff_t *ppos);
18
19typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip);
20
21struct ftrace_ops {
22 ftrace_func_t func;
23 struct ftrace_ops *next;
24};
25
26/*
27 * The ftrace_ops must be a static and should also
28 * be read_mostly. These functions do modify read_mostly variables
29 * so use them sparely. Never free an ftrace_op or modify the
30 * next pointer after it has been registered. Even after unregistering
31 * it, the next pointer may still be used internally.
32 */
33int register_ftrace_function(struct ftrace_ops *ops);
34int unregister_ftrace_function(struct ftrace_ops *ops);
35void clear_ftrace_function(void);
36
37extern void ftrace_stub(unsigned long a0, unsigned long a1);
38
39#else /* !CONFIG_FUNCTION_TRACER */
40# define register_ftrace_function(ops) do { } while (0)
41# define unregister_ftrace_function(ops) do { } while (0)
42# define clear_ftrace_function(ops) do { } while (0)
43static inline void ftrace_kill(void) { }
44#endif /* CONFIG_FUNCTION_TRACER */
45
46#ifdef CONFIG_DYNAMIC_FTRACE
47
48enum {
49 FTRACE_FL_FREE = (1 << 0),
50 FTRACE_FL_FAILED = (1 << 1),
51 FTRACE_FL_FILTER = (1 << 2),
52 FTRACE_FL_ENABLED = (1 << 3),
53 FTRACE_FL_NOTRACE = (1 << 4),
54 FTRACE_FL_CONVERTED = (1 << 5),
55 FTRACE_FL_FROZEN = (1 << 6),
56};
57
58struct dyn_ftrace {
59 struct list_head list;
60 unsigned long ip; /* address of mcount call-site */
61 unsigned long flags;
62};
63
64int ftrace_force_update(void);
65void ftrace_set_filter(unsigned char *buf, int len, int reset);
66
67/* defined in arch */
68extern int ftrace_ip_converted(unsigned long ip);
69extern unsigned char *ftrace_nop_replace(void);
70extern unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr);
71extern int ftrace_dyn_arch_init(void *data);
72extern int ftrace_update_ftrace_func(ftrace_func_t func);
73extern void ftrace_caller(void);
74extern void ftrace_call(void);
75extern void mcount_call(void);
76
77/**
78 * ftrace_modify_code - modify code segment
79 * @ip: the address of the code segment
80 * @old_code: the contents of what is expected to be there
81 * @new_code: the code to patch in
82 *
83 * This is a very sensitive operation and great care needs
84 * to be taken by the arch. The operation should carefully
85 * read the location, check to see if what is read is indeed
86 * what we expect it to be, and then on success of the compare,
87 * it should write to the location.
88 *
89 * Return must be:
90 * 0 on success
91 * -EFAULT on error reading the location
92 * -EINVAL on a failed compare of the contents
93 * -EPERM on error writing to the location
94 * Any other value will be considered a failure.
95 */
96extern int ftrace_modify_code(unsigned long ip, unsigned char *old_code,
97 unsigned char *new_code);
98
99extern int skip_trace(unsigned long ip);
100
101extern void ftrace_release(void *start, unsigned long size);
102
103extern void ftrace_disable_daemon(void);
104extern void ftrace_enable_daemon(void);
105
106#else
107# define skip_trace(ip) ({ 0; })
108# define ftrace_force_update() ({ 0; })
109# define ftrace_set_filter(buf, len, reset) do { } while (0)
110# define ftrace_disable_daemon() do { } while (0)
111# define ftrace_enable_daemon() do { } while (0)
112static inline void ftrace_release(void *start, unsigned long size) { }
113#endif /* CONFIG_DYNAMIC_FTRACE */
114
115/* totally disable ftrace - can not re-enable after this */
116void ftrace_kill(void);
117
118static inline void tracer_disable(void)
119{
120#ifdef CONFIG_FUNCTION_TRACER
121 ftrace_enabled = 0;
122#endif
123}
124
125/*
126 * Ftrace disable/restore without lock. Some synchronization mechanism
127 * must be used to prevent ftrace_enabled to be changed between
128 * disable/restore.
129 */
130static inline int __ftrace_enabled_save(void)
131{
132#ifdef CONFIG_FUNCTION_TRACER
133 int saved_ftrace_enabled = ftrace_enabled;
134 ftrace_enabled = 0;
135 return saved_ftrace_enabled;
136#else
137 return 0;
138#endif
139}
140
141static inline void __ftrace_enabled_restore(int enabled)
142{
143#ifdef CONFIG_FUNCTION_TRACER
144 ftrace_enabled = enabled;
145#endif
146}
147
148#ifdef CONFIG_FRAME_POINTER
149/* TODO: need to fix this for ARM */
150# define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
151# define CALLER_ADDR1 ((unsigned long)__builtin_return_address(1))
152# define CALLER_ADDR2 ((unsigned long)__builtin_return_address(2))
153# define CALLER_ADDR3 ((unsigned long)__builtin_return_address(3))
154# define CALLER_ADDR4 ((unsigned long)__builtin_return_address(4))
155# define CALLER_ADDR5 ((unsigned long)__builtin_return_address(5))
156# define CALLER_ADDR6 ((unsigned long)__builtin_return_address(6))
157#else
158# define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
159# define CALLER_ADDR1 0UL
160# define CALLER_ADDR2 0UL
161# define CALLER_ADDR3 0UL
162# define CALLER_ADDR4 0UL
163# define CALLER_ADDR5 0UL
164# define CALLER_ADDR6 0UL
165#endif
166
167#ifdef CONFIG_IRQSOFF_TRACER
168 extern void time_hardirqs_on(unsigned long a0, unsigned long a1);
169 extern void time_hardirqs_off(unsigned long a0, unsigned long a1);
170#else
171# define time_hardirqs_on(a0, a1) do { } while (0)
172# define time_hardirqs_off(a0, a1) do { } while (0)
173#endif
174
175#ifdef CONFIG_PREEMPT_TRACER
176 extern void trace_preempt_on(unsigned long a0, unsigned long a1);
177 extern void trace_preempt_off(unsigned long a0, unsigned long a1);
178#else
179# define trace_preempt_on(a0, a1) do { } while (0)
180# define trace_preempt_off(a0, a1) do { } while (0)
181#endif
182
183#ifdef CONFIG_TRACING
184extern void
185ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3);
186
187/**
188 * ftrace_printk - printf formatting in the ftrace buffer
189 * @fmt: the printf format for printing
190 *
191 * Note: __ftrace_printk is an internal function for ftrace_printk and
192 * the @ip is passed in via the ftrace_printk macro.
193 *
194 * This function allows a kernel developer to debug fast path sections
195 * that printk is not appropriate for. By scattering in various
196 * printk like tracing in the code, a developer can quickly see
197 * where problems are occurring.
198 *
199 * This is intended as a debugging tool for the developer only.
200 * Please refrain from leaving ftrace_printks scattered around in
201 * your code.
202 */
203# define ftrace_printk(fmt...) __ftrace_printk(_THIS_IP_, fmt)
204extern int
205__ftrace_printk(unsigned long ip, const char *fmt, ...)
206 __attribute__ ((format (printf, 2, 3)));
207extern void ftrace_dump(void);
208#else
209static inline void
210ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3) { }
211static inline int
212ftrace_printk(const char *fmt, ...) __attribute__ ((format (printf, 1, 0)));
213
214static inline int
215ftrace_printk(const char *fmt, ...)
216{
217 return 0;
218}
219static inline void ftrace_dump(void) { }
220#endif
221
222#ifdef CONFIG_FTRACE_MCOUNT_RECORD
223extern void ftrace_init(void);
224extern void ftrace_init_module(unsigned long *start, unsigned long *end);
225#else
226static inline void ftrace_init(void) { }
227static inline void
228ftrace_init_module(unsigned long *start, unsigned long *end) { }
229#endif
230
231
232struct boot_trace {
233 pid_t caller;
234 char func[KSYM_NAME_LEN];
235 int result;
236 unsigned long long duration; /* usecs */
237 ktime_t calltime;
238 ktime_t rettime;
239};
240
241#ifdef CONFIG_BOOT_TRACER
242extern void trace_boot(struct boot_trace *it, initcall_t fn);
243extern void start_boot_trace(void);
244extern void stop_boot_trace(void);
245#else
246static inline void trace_boot(struct boot_trace *it, initcall_t fn) { }
247static inline void start_boot_trace(void) { }
248static inline void stop_boot_trace(void) { }
249#endif
250
251
252
253#endif /* _LINUX_FTRACE_H */