1 #ifndef _LINUX_FTRACE_H
2 #define _LINUX_FTRACE_H
4 #include <linux/linkage.h>
6 #include <linux/ktime.h>
7 #include <linux/init.h>
8 #include <linux/types.h>
9 #include <linux/kallsyms.h>
11 #ifdef CONFIG_FUNCTION_TRACER
13 extern int ftrace_enabled;
15 ftrace_enable_sysctl(struct ctl_table *table, int write,
16 struct file *filp, void __user *buffer, size_t *lenp,
19 typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip);
23 struct ftrace_ops *next;
26 extern int function_trace_stop;
29 * ftrace_stop - stop function tracer.
31 * A quick way to stop the function tracer. Note this an on off switch,
32 * it is not something that is recursive like preempt_disable.
33 * This does not disable the calling of mcount, it only stops the
34 * calling of functions from mcount.
36 static inline void ftrace_stop(void)
38 function_trace_stop = 1;
42 * ftrace_start - start the function tracer.
44 * This function is the inverse of ftrace_stop. This does not enable
45 * the function tracing if the function tracer is disabled. This only
46 * sets the function tracer flag to continue calling the functions
49 static inline void ftrace_start(void)
51 function_trace_stop = 0;
55 * The ftrace_ops must be a static and should also
56 * be read_mostly. These functions do modify read_mostly variables
57 * so use them sparely. Never free an ftrace_op or modify the
58 * next pointer after it has been registered. Even after unregistering
59 * it, the next pointer may still be used internally.
61 int register_ftrace_function(struct ftrace_ops *ops);
62 int unregister_ftrace_function(struct ftrace_ops *ops);
63 void clear_ftrace_function(void);
65 extern void ftrace_stub(unsigned long a0, unsigned long a1);
67 #else /* !CONFIG_FUNCTION_TRACER */
68 # define register_ftrace_function(ops) do { } while (0)
69 # define unregister_ftrace_function(ops) do { } while (0)
70 # define clear_ftrace_function(ops) do { } while (0)
71 static inline void ftrace_kill(void) { }
72 static inline void ftrace_stop(void) { }
73 static inline void ftrace_start(void) { }
74 #endif /* CONFIG_FUNCTION_TRACER */
76 #ifdef CONFIG_DYNAMIC_FTRACE
77 /* asm/ftrace.h must be defined for archs supporting dynamic ftrace */
78 #include <asm/ftrace.h>
81 FTRACE_FL_FREE = (1 << 0),
82 FTRACE_FL_FAILED = (1 << 1),
83 FTRACE_FL_FILTER = (1 << 2),
84 FTRACE_FL_ENABLED = (1 << 3),
85 FTRACE_FL_NOTRACE = (1 << 4),
86 FTRACE_FL_CONVERTED = (1 << 5),
87 FTRACE_FL_FROZEN = (1 << 6),
91 struct list_head list;
92 unsigned long ip; /* address of mcount call-site */
94 struct dyn_arch_ftrace arch;
97 int ftrace_force_update(void);
98 void ftrace_set_filter(unsigned char *buf, int len, int reset);
100 /* defined in arch */
101 extern int ftrace_ip_converted(unsigned long ip);
102 extern int ftrace_dyn_arch_init(void *data);
103 extern int ftrace_update_ftrace_func(ftrace_func_t func);
104 extern void ftrace_caller(void);
105 extern void ftrace_call(void);
106 extern void mcount_call(void);
109 * ftrace_make_nop - convert code into top
110 * @mod: module structure if called by module load initialization
111 * @rec: the mcount call site record
112 * @addr: the address that the call site should be calling
114 * This is a very sensitive operation and great care needs
115 * to be taken by the arch. The operation should carefully
116 * read the location, check to see if what is read is indeed
117 * what we expect it to be, and then on success of the compare,
118 * it should write to the location.
120 * The code segment at @rec->ip should be a caller to @addr
124 * -EFAULT on error reading the location
125 * -EINVAL on a failed compare of the contents
126 * -EPERM on error writing to the location
127 * Any other value will be considered a failure.
129 extern int ftrace_make_nop(struct module *mod,
130 struct dyn_ftrace *rec, unsigned long addr);
133 * ftrace_make_call - convert a nop call site into a call to addr
134 * @rec: the mcount call site record
135 * @addr: the address that the call site should call
137 * This is a very sensitive operation and great care needs
138 * to be taken by the arch. The operation should carefully
139 * read the location, check to see if what is read is indeed
140 * what we expect it to be, and then on success of the compare,
141 * it should write to the location.
143 * The code segment at @rec->ip should be a nop
147 * -EFAULT on error reading the location
148 * -EINVAL on a failed compare of the contents
149 * -EPERM on error writing to the location
150 * Any other value will be considered a failure.
152 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr);
155 /* May be defined in arch */
156 extern int ftrace_arch_read_dyn_info(char *buf, int size);
158 extern int skip_trace(unsigned long ip);
160 extern void ftrace_release(void *start, unsigned long size);
162 extern void ftrace_disable_daemon(void);
163 extern void ftrace_enable_daemon(void);
165 # define skip_trace(ip) ({ 0; })
166 # define ftrace_force_update() ({ 0; })
167 # define ftrace_set_filter(buf, len, reset) do { } while (0)
168 # define ftrace_disable_daemon() do { } while (0)
169 # define ftrace_enable_daemon() do { } while (0)
170 static inline void ftrace_release(void *start, unsigned long size) { }
171 #endif /* CONFIG_DYNAMIC_FTRACE */
173 /* totally disable ftrace - can not re-enable after this */
174 void ftrace_kill(void);
176 static inline void tracer_disable(void)
178 #ifdef CONFIG_FUNCTION_TRACER
184 * Ftrace disable/restore without lock. Some synchronization mechanism
185 * must be used to prevent ftrace_enabled to be changed between
188 static inline int __ftrace_enabled_save(void)
190 #ifdef CONFIG_FUNCTION_TRACER
191 int saved_ftrace_enabled = ftrace_enabled;
193 return saved_ftrace_enabled;
199 static inline void __ftrace_enabled_restore(int enabled)
201 #ifdef CONFIG_FUNCTION_TRACER
202 ftrace_enabled = enabled;
206 #ifdef CONFIG_FRAME_POINTER
207 /* TODO: need to fix this for ARM */
208 # define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
209 # define CALLER_ADDR1 ((unsigned long)__builtin_return_address(1))
210 # define CALLER_ADDR2 ((unsigned long)__builtin_return_address(2))
211 # define CALLER_ADDR3 ((unsigned long)__builtin_return_address(3))
212 # define CALLER_ADDR4 ((unsigned long)__builtin_return_address(4))
213 # define CALLER_ADDR5 ((unsigned long)__builtin_return_address(5))
214 # define CALLER_ADDR6 ((unsigned long)__builtin_return_address(6))
216 # define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
217 # define CALLER_ADDR1 0UL
218 # define CALLER_ADDR2 0UL
219 # define CALLER_ADDR3 0UL
220 # define CALLER_ADDR4 0UL
221 # define CALLER_ADDR5 0UL
222 # define CALLER_ADDR6 0UL
225 #ifdef CONFIG_IRQSOFF_TRACER
226 extern void time_hardirqs_on(unsigned long a0, unsigned long a1);
227 extern void time_hardirqs_off(unsigned long a0, unsigned long a1);
229 # define time_hardirqs_on(a0, a1) do { } while (0)
230 # define time_hardirqs_off(a0, a1) do { } while (0)
233 #ifdef CONFIG_PREEMPT_TRACER
234 extern void trace_preempt_on(unsigned long a0, unsigned long a1);
235 extern void trace_preempt_off(unsigned long a0, unsigned long a1);
237 # define trace_preempt_on(a0, a1) do { } while (0)
238 # define trace_preempt_off(a0, a1) do { } while (0)
241 #ifdef CONFIG_TRACING
242 extern int ftrace_dump_on_oops;
244 extern void tracing_start(void);
245 extern void tracing_stop(void);
248 ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3);
251 * ftrace_printk - printf formatting in the ftrace buffer
252 * @fmt: the printf format for printing
254 * Note: __ftrace_printk is an internal function for ftrace_printk and
255 * the @ip is passed in via the ftrace_printk macro.
257 * This function allows a kernel developer to debug fast path sections
258 * that printk is not appropriate for. By scattering in various
259 * printk like tracing in the code, a developer can quickly see
260 * where problems are occurring.
262 * This is intended as a debugging tool for the developer only.
263 * Please refrain from leaving ftrace_printks scattered around in
266 # define ftrace_printk(fmt...) __ftrace_printk(_THIS_IP_, fmt)
268 __ftrace_printk(unsigned long ip, const char *fmt, ...)
269 __attribute__ ((format (printf, 2, 3)));
270 extern void ftrace_dump(void);
273 ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3) { }
275 ftrace_printk(const char *fmt, ...) __attribute__ ((format (printf, 1, 0)));
277 static inline void tracing_start(void) { }
278 static inline void tracing_stop(void) { }
280 ftrace_printk(const char *fmt, ...)
284 static inline void ftrace_dump(void) { }
287 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
288 extern void ftrace_init(void);
289 extern void ftrace_init_module(struct module *mod,
290 unsigned long *start, unsigned long *end);
292 static inline void ftrace_init(void) { }
294 ftrace_init_module(struct module *mod,
295 unsigned long *start, unsigned long *end) { }
300 * Structure that defines a return function trace.
302 struct ftrace_retfunc {
303 unsigned long ret; /* Return address */
304 unsigned long func; /* Current function */
305 unsigned long long calltime;
306 unsigned long long rettime;
309 #ifdef CONFIG_FUNCTION_RET_TRACER
310 /* Type of a callback handler of tracing return function */
311 typedef void (*trace_function_return_t)(struct ftrace_retfunc *);
313 extern void register_ftrace_return(trace_function_return_t func);
314 /* The current handler in use */
315 extern trace_function_return_t ftrace_function_return;
316 extern void unregister_ftrace_return(void);
319 #endif /* _LINUX_FTRACE_H */