Merge branch 'docs-next' of git://git.lwn.net/linux-2.6
[linux-2.6/next.git] / include / linux / ftrace.h
blob0b4f97d24d7f510b243bdd8cd461daa2786eaa19
1 #ifndef _LINUX_FTRACE_H
2 #define _LINUX_FTRACE_H
4 #include <linux/trace_clock.h>
5 #include <linux/kallsyms.h>
6 #include <linux/linkage.h>
7 #include <linux/bitops.h>
8 #include <linux/module.h>
9 #include <linux/ktime.h>
10 #include <linux/sched.h>
11 #include <linux/types.h>
12 #include <linux/init.h>
13 #include <linux/fs.h>
15 #include <asm/ftrace.h>
17 #ifdef CONFIG_FUNCTION_TRACER
19 extern int ftrace_enabled;
20 extern int
21 ftrace_enable_sysctl(struct ctl_table *table, int write,
22 void __user *buffer, size_t *lenp,
23 loff_t *ppos);
25 typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip);
27 struct ftrace_ops {
28 ftrace_func_t func;
29 struct ftrace_ops *next;
32 extern int function_trace_stop;
35 * Type of the current tracing.
37 enum ftrace_tracing_type_t {
38 FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */
39 FTRACE_TYPE_RETURN, /* Hook the return of the function */
42 /* Current tracing type, default is FTRACE_TYPE_ENTER */
43 extern enum ftrace_tracing_type_t ftrace_tracing_type;
45 /**
46 * ftrace_stop - stop function tracer.
48 * A quick way to stop the function tracer. Note this an on off switch,
49 * it is not something that is recursive like preempt_disable.
50 * This does not disable the calling of mcount, it only stops the
51 * calling of functions from mcount.
53 static inline void ftrace_stop(void)
55 function_trace_stop = 1;
58 /**
59 * ftrace_start - start the function tracer.
61 * This function is the inverse of ftrace_stop. This does not enable
62 * the function tracing if the function tracer is disabled. This only
63 * sets the function tracer flag to continue calling the functions
64 * from mcount.
66 static inline void ftrace_start(void)
68 function_trace_stop = 0;
72 * The ftrace_ops must be a static and should also
73 * be read_mostly. These functions do modify read_mostly variables
74 * so use them sparely. Never free an ftrace_op or modify the
75 * next pointer after it has been registered. Even after unregistering
76 * it, the next pointer may still be used internally.
78 int register_ftrace_function(struct ftrace_ops *ops);
79 int unregister_ftrace_function(struct ftrace_ops *ops);
80 void clear_ftrace_function(void);
82 extern void ftrace_stub(unsigned long a0, unsigned long a1);
84 #else /* !CONFIG_FUNCTION_TRACER */
85 # define register_ftrace_function(ops) do { } while (0)
86 # define unregister_ftrace_function(ops) do { } while (0)
87 # define clear_ftrace_function(ops) do { } while (0)
88 static inline void ftrace_kill(void) { }
89 static inline void ftrace_stop(void) { }
90 static inline void ftrace_start(void) { }
91 #endif /* CONFIG_FUNCTION_TRACER */
93 #ifdef CONFIG_STACK_TRACER
94 extern int stack_tracer_enabled;
95 int
96 stack_trace_sysctl(struct ctl_table *table, int write,
97 void __user *buffer, size_t *lenp,
98 loff_t *ppos);
99 #endif
101 struct ftrace_func_command {
102 struct list_head list;
103 char *name;
104 int (*func)(char *func, char *cmd,
105 char *params, int enable);
108 #ifdef CONFIG_DYNAMIC_FTRACE
110 int ftrace_arch_code_modify_prepare(void);
111 int ftrace_arch_code_modify_post_process(void);
113 struct seq_file;
115 struct ftrace_probe_ops {
116 void (*func)(unsigned long ip,
117 unsigned long parent_ip,
118 void **data);
119 int (*callback)(unsigned long ip, void **data);
120 void (*free)(void **data);
121 int (*print)(struct seq_file *m,
122 unsigned long ip,
123 struct ftrace_probe_ops *ops,
124 void *data);
127 extern int
128 register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
129 void *data);
130 extern void
131 unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
132 void *data);
133 extern void
134 unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops);
135 extern void unregister_ftrace_function_probe_all(char *glob);
137 enum {
138 FTRACE_FL_FREE = (1 << 0),
139 FTRACE_FL_FAILED = (1 << 1),
140 FTRACE_FL_FILTER = (1 << 2),
141 FTRACE_FL_ENABLED = (1 << 3),
142 FTRACE_FL_NOTRACE = (1 << 4),
143 FTRACE_FL_CONVERTED = (1 << 5),
144 FTRACE_FL_FROZEN = (1 << 6),
147 struct dyn_ftrace {
148 union {
149 unsigned long ip; /* address of mcount call-site */
150 struct dyn_ftrace *freelist;
152 union {
153 unsigned long flags;
154 struct dyn_ftrace *newlist;
156 struct dyn_arch_ftrace arch;
159 int ftrace_force_update(void);
160 void ftrace_set_filter(unsigned char *buf, int len, int reset);
162 int register_ftrace_command(struct ftrace_func_command *cmd);
163 int unregister_ftrace_command(struct ftrace_func_command *cmd);
165 /* defined in arch */
166 extern int ftrace_ip_converted(unsigned long ip);
167 extern int ftrace_dyn_arch_init(void *data);
168 extern int ftrace_update_ftrace_func(ftrace_func_t func);
169 extern void ftrace_caller(void);
170 extern void ftrace_call(void);
171 extern void mcount_call(void);
173 #ifndef FTRACE_ADDR
174 #define FTRACE_ADDR ((unsigned long)ftrace_caller)
175 #endif
176 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
177 extern void ftrace_graph_caller(void);
178 extern int ftrace_enable_ftrace_graph_caller(void);
179 extern int ftrace_disable_ftrace_graph_caller(void);
180 #else
181 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; }
182 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; }
183 #endif
186 * ftrace_make_nop - convert code into nop
187 * @mod: module structure if called by module load initialization
188 * @rec: the mcount call site record
189 * @addr: the address that the call site should be calling
191 * This is a very sensitive operation and great care needs
192 * to be taken by the arch. The operation should carefully
193 * read the location, check to see if what is read is indeed
194 * what we expect it to be, and then on success of the compare,
195 * it should write to the location.
197 * The code segment at @rec->ip should be a caller to @addr
199 * Return must be:
200 * 0 on success
201 * -EFAULT on error reading the location
202 * -EINVAL on a failed compare of the contents
203 * -EPERM on error writing to the location
204 * Any other value will be considered a failure.
206 extern int ftrace_make_nop(struct module *mod,
207 struct dyn_ftrace *rec, unsigned long addr);
210 * ftrace_make_call - convert a nop call site into a call to addr
211 * @rec: the mcount call site record
212 * @addr: the address that the call site should call
214 * This is a very sensitive operation and great care needs
215 * to be taken by the arch. The operation should carefully
216 * read the location, check to see if what is read is indeed
217 * what we expect it to be, and then on success of the compare,
218 * it should write to the location.
220 * The code segment at @rec->ip should be a nop
222 * Return must be:
223 * 0 on success
224 * -EFAULT on error reading the location
225 * -EINVAL on a failed compare of the contents
226 * -EPERM on error writing to the location
227 * Any other value will be considered a failure.
229 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr);
231 /* May be defined in arch */
232 extern int ftrace_arch_read_dyn_info(char *buf, int size);
234 extern int skip_trace(unsigned long ip);
236 extern void ftrace_disable_daemon(void);
237 extern void ftrace_enable_daemon(void);
238 #else
239 # define skip_trace(ip) ({ 0; })
240 # define ftrace_force_update() ({ 0; })
241 # define ftrace_set_filter(buf, len, reset) do { } while (0)
242 # define ftrace_disable_daemon() do { } while (0)
243 # define ftrace_enable_daemon() do { } while (0)
244 static inline void ftrace_release_mod(struct module *mod) {}
245 static inline int register_ftrace_command(struct ftrace_func_command *cmd)
247 return -EINVAL;
249 static inline int unregister_ftrace_command(char *cmd_name)
251 return -EINVAL;
253 #endif /* CONFIG_DYNAMIC_FTRACE */
255 /* totally disable ftrace - can not re-enable after this */
256 void ftrace_kill(void);
258 static inline void tracer_disable(void)
260 #ifdef CONFIG_FUNCTION_TRACER
261 ftrace_enabled = 0;
262 #endif
266 * Ftrace disable/restore without lock. Some synchronization mechanism
267 * must be used to prevent ftrace_enabled to be changed between
268 * disable/restore.
270 static inline int __ftrace_enabled_save(void)
272 #ifdef CONFIG_FUNCTION_TRACER
273 int saved_ftrace_enabled = ftrace_enabled;
274 ftrace_enabled = 0;
275 return saved_ftrace_enabled;
276 #else
277 return 0;
278 #endif
281 static inline void __ftrace_enabled_restore(int enabled)
283 #ifdef CONFIG_FUNCTION_TRACER
284 ftrace_enabled = enabled;
285 #endif
288 #ifndef HAVE_ARCH_CALLER_ADDR
289 # ifdef CONFIG_FRAME_POINTER
290 # define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
291 # define CALLER_ADDR1 ((unsigned long)__builtin_return_address(1))
292 # define CALLER_ADDR2 ((unsigned long)__builtin_return_address(2))
293 # define CALLER_ADDR3 ((unsigned long)__builtin_return_address(3))
294 # define CALLER_ADDR4 ((unsigned long)__builtin_return_address(4))
295 # define CALLER_ADDR5 ((unsigned long)__builtin_return_address(5))
296 # define CALLER_ADDR6 ((unsigned long)__builtin_return_address(6))
297 # else
298 # define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
299 # define CALLER_ADDR1 0UL
300 # define CALLER_ADDR2 0UL
301 # define CALLER_ADDR3 0UL
302 # define CALLER_ADDR4 0UL
303 # define CALLER_ADDR5 0UL
304 # define CALLER_ADDR6 0UL
305 # endif
306 #endif /* ifndef HAVE_ARCH_CALLER_ADDR */
308 #ifdef CONFIG_IRQSOFF_TRACER
309 extern void time_hardirqs_on(unsigned long a0, unsigned long a1);
310 extern void time_hardirqs_off(unsigned long a0, unsigned long a1);
311 #else
312 # define time_hardirqs_on(a0, a1) do { } while (0)
313 # define time_hardirqs_off(a0, a1) do { } while (0)
314 #endif
316 #ifdef CONFIG_PREEMPT_TRACER
317 extern void trace_preempt_on(unsigned long a0, unsigned long a1);
318 extern void trace_preempt_off(unsigned long a0, unsigned long a1);
319 #else
320 # define trace_preempt_on(a0, a1) do { } while (0)
321 # define trace_preempt_off(a0, a1) do { } while (0)
322 #endif
324 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
325 extern void ftrace_init(void);
326 #else
327 static inline void ftrace_init(void) { }
328 #endif
331 * Structure that defines an entry function trace.
333 struct ftrace_graph_ent {
334 unsigned long func; /* Current function */
335 int depth;
339 * Structure that defines a return function trace.
341 struct ftrace_graph_ret {
342 unsigned long func; /* Current function */
343 unsigned long long calltime;
344 unsigned long long rettime;
345 /* Number of functions that overran the depth limit for current task */
346 unsigned long overrun;
347 int depth;
350 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
352 /* for init task */
353 #define INIT_FTRACE_GRAPH .ret_stack = NULL,
356 * Stack of return addresses for functions
357 * of a thread.
358 * Used in struct thread_info
360 struct ftrace_ret_stack {
361 unsigned long ret;
362 unsigned long func;
363 unsigned long long calltime;
364 unsigned long long subtime;
365 unsigned long fp;
369 * Primary handler of a function return.
370 * It relays on ftrace_return_to_handler.
371 * Defined in entry_32/64.S
373 extern void return_to_handler(void);
375 extern int
376 ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
377 unsigned long frame_pointer);
380 * Sometimes we don't want to trace a function with the function
381 * graph tracer but we want them to keep traced by the usual function
382 * tracer if the function graph tracer is not configured.
384 #define __notrace_funcgraph notrace
387 * We want to which function is an entrypoint of a hardirq.
388 * That will help us to put a signal on output.
390 #define __irq_entry __attribute__((__section__(".irqentry.text")))
392 /* Limits of hardirq entrypoints */
393 extern char __irqentry_text_start[];
394 extern char __irqentry_text_end[];
396 #define FTRACE_RETFUNC_DEPTH 50
397 #define FTRACE_RETSTACK_ALLOC_SIZE 32
398 /* Type of the callback handlers for tracing function graph*/
399 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */
400 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */
402 extern int register_ftrace_graph(trace_func_graph_ret_t retfunc,
403 trace_func_graph_ent_t entryfunc);
405 extern void ftrace_graph_stop(void);
407 /* The current handlers in use */
408 extern trace_func_graph_ret_t ftrace_graph_return;
409 extern trace_func_graph_ent_t ftrace_graph_entry;
411 extern void unregister_ftrace_graph(void);
413 extern void ftrace_graph_init_task(struct task_struct *t);
414 extern void ftrace_graph_exit_task(struct task_struct *t);
416 static inline int task_curr_ret_stack(struct task_struct *t)
418 return t->curr_ret_stack;
421 static inline void pause_graph_tracing(void)
423 atomic_inc(&current->tracing_graph_pause);
426 static inline void unpause_graph_tracing(void)
428 atomic_dec(&current->tracing_graph_pause);
430 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */
432 #define __notrace_funcgraph
433 #define __irq_entry
434 #define INIT_FTRACE_GRAPH
436 static inline void ftrace_graph_init_task(struct task_struct *t) { }
437 static inline void ftrace_graph_exit_task(struct task_struct *t) { }
439 static inline int task_curr_ret_stack(struct task_struct *tsk)
441 return -1;
444 static inline void pause_graph_tracing(void) { }
445 static inline void unpause_graph_tracing(void) { }
446 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
448 #ifdef CONFIG_TRACING
450 /* flags for current->trace */
451 enum {
452 TSK_TRACE_FL_TRACE_BIT = 0,
453 TSK_TRACE_FL_GRAPH_BIT = 1,
455 enum {
456 TSK_TRACE_FL_TRACE = 1 << TSK_TRACE_FL_TRACE_BIT,
457 TSK_TRACE_FL_GRAPH = 1 << TSK_TRACE_FL_GRAPH_BIT,
460 static inline void set_tsk_trace_trace(struct task_struct *tsk)
462 set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
465 static inline void clear_tsk_trace_trace(struct task_struct *tsk)
467 clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
470 static inline int test_tsk_trace_trace(struct task_struct *tsk)
472 return tsk->trace & TSK_TRACE_FL_TRACE;
475 static inline void set_tsk_trace_graph(struct task_struct *tsk)
477 set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
480 static inline void clear_tsk_trace_graph(struct task_struct *tsk)
482 clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
485 static inline int test_tsk_trace_graph(struct task_struct *tsk)
487 return tsk->trace & TSK_TRACE_FL_GRAPH;
490 extern int ftrace_dump_on_oops;
492 #ifdef CONFIG_PREEMPT
493 #define INIT_TRACE_RECURSION .trace_recursion = 0,
494 #endif
496 #endif /* CONFIG_TRACING */
498 #ifndef INIT_TRACE_RECURSION
499 #define INIT_TRACE_RECURSION
500 #endif
502 #ifdef CONFIG_HW_BRANCH_TRACER
504 void trace_hw_branch(u64 from, u64 to);
505 void trace_hw_branch_oops(void);
507 #else /* CONFIG_HW_BRANCH_TRACER */
509 static inline void trace_hw_branch(u64 from, u64 to) {}
510 static inline void trace_hw_branch_oops(void) {}
512 #endif /* CONFIG_HW_BRANCH_TRACER */
514 #endif /* _LINUX_FTRACE_H */