ftrace.h 15 KB

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  1. #ifndef _LINUX_FTRACE_H
  2. #define _LINUX_FTRACE_H
  3. #include <linux/linkage.h>
  4. #include <linux/fs.h>
  5. #include <linux/ktime.h>
  6. #include <linux/init.h>
  7. #include <linux/types.h>
  8. #include <linux/module.h>
  9. #include <linux/kallsyms.h>
  10. #include <linux/bitops.h>
  11. #include <linux/sched.h>
  12. #ifdef CONFIG_FUNCTION_TRACER
  13. extern int ftrace_enabled;
  14. extern int
  15. ftrace_enable_sysctl(struct ctl_table *table, int write,
  16. struct file *filp, void __user *buffer, size_t *lenp,
  17. loff_t *ppos);
  18. typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip);
  19. struct ftrace_ops {
  20. ftrace_func_t func;
  21. struct ftrace_ops *next;
  22. };
  23. extern int function_trace_stop;
  24. /*
  25. * Type of the current tracing.
  26. */
  27. enum ftrace_tracing_type_t {
  28. FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */
  29. FTRACE_TYPE_RETURN, /* Hook the return of the function */
  30. };
  31. /* Current tracing type, default is FTRACE_TYPE_ENTER */
  32. extern enum ftrace_tracing_type_t ftrace_tracing_type;
  33. /**
  34. * ftrace_stop - stop function tracer.
  35. *
  36. * A quick way to stop the function tracer. Note this an on off switch,
  37. * it is not something that is recursive like preempt_disable.
  38. * This does not disable the calling of mcount, it only stops the
  39. * calling of functions from mcount.
  40. */
  41. static inline void ftrace_stop(void)
  42. {
  43. function_trace_stop = 1;
  44. }
  45. /**
  46. * ftrace_start - start the function tracer.
  47. *
  48. * This function is the inverse of ftrace_stop. This does not enable
  49. * the function tracing if the function tracer is disabled. This only
  50. * sets the function tracer flag to continue calling the functions
  51. * from mcount.
  52. */
  53. static inline void ftrace_start(void)
  54. {
  55. function_trace_stop = 0;
  56. }
  57. /*
  58. * The ftrace_ops must be a static and should also
  59. * be read_mostly. These functions do modify read_mostly variables
  60. * so use them sparely. Never free an ftrace_op or modify the
  61. * next pointer after it has been registered. Even after unregistering
  62. * it, the next pointer may still be used internally.
  63. */
  64. int register_ftrace_function(struct ftrace_ops *ops);
  65. int unregister_ftrace_function(struct ftrace_ops *ops);
  66. void clear_ftrace_function(void);
  67. extern void ftrace_stub(unsigned long a0, unsigned long a1);
  68. #else /* !CONFIG_FUNCTION_TRACER */
  69. # define register_ftrace_function(ops) do { } while (0)
  70. # define unregister_ftrace_function(ops) do { } while (0)
  71. # define clear_ftrace_function(ops) do { } while (0)
  72. static inline void ftrace_kill(void) { }
  73. static inline void ftrace_stop(void) { }
  74. static inline void ftrace_start(void) { }
  75. #endif /* CONFIG_FUNCTION_TRACER */
  76. #ifdef CONFIG_STACK_TRACER
  77. extern int stack_tracer_enabled;
  78. int
  79. stack_trace_sysctl(struct ctl_table *table, int write,
  80. struct file *file, void __user *buffer, size_t *lenp,
  81. loff_t *ppos);
  82. #endif
  83. struct ftrace_func_command {
  84. struct list_head list;
  85. char *name;
  86. int (*func)(char *func, char *cmd,
  87. char *params, int enable);
  88. };
  89. #ifdef CONFIG_DYNAMIC_FTRACE
  90. /* asm/ftrace.h must be defined for archs supporting dynamic ftrace */
  91. #include <asm/ftrace.h>
  92. struct seq_file;
  93. struct ftrace_probe_ops {
  94. void (*func)(unsigned long ip,
  95. unsigned long parent_ip,
  96. void **data);
  97. int (*callback)(unsigned long ip, void **data);
  98. void (*free)(void **data);
  99. int (*print)(struct seq_file *m,
  100. unsigned long ip,
  101. struct ftrace_probe_ops *ops,
  102. void *data);
  103. };
  104. extern int
  105. register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
  106. void *data);
  107. extern void
  108. unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
  109. void *data);
  110. extern void
  111. unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops);
  112. extern void unregister_ftrace_function_probe_all(char *glob);
  113. enum {
  114. FTRACE_FL_FREE = (1 << 0),
  115. FTRACE_FL_FAILED = (1 << 1),
  116. FTRACE_FL_FILTER = (1 << 2),
  117. FTRACE_FL_ENABLED = (1 << 3),
  118. FTRACE_FL_NOTRACE = (1 << 4),
  119. FTRACE_FL_CONVERTED = (1 << 5),
  120. FTRACE_FL_FROZEN = (1 << 6),
  121. };
  122. struct dyn_ftrace {
  123. struct list_head list;
  124. unsigned long ip; /* address of mcount call-site */
  125. unsigned long flags;
  126. struct dyn_arch_ftrace arch;
  127. };
  128. int ftrace_force_update(void);
  129. void ftrace_set_filter(unsigned char *buf, int len, int reset);
  130. int register_ftrace_command(struct ftrace_func_command *cmd);
  131. int unregister_ftrace_command(struct ftrace_func_command *cmd);
  132. /* defined in arch */
  133. extern int ftrace_ip_converted(unsigned long ip);
  134. extern int ftrace_dyn_arch_init(void *data);
  135. extern int ftrace_update_ftrace_func(ftrace_func_t func);
  136. extern void ftrace_caller(void);
  137. extern void ftrace_call(void);
  138. extern void mcount_call(void);
  139. #ifndef FTRACE_ADDR
  140. #define FTRACE_ADDR ((unsigned long)ftrace_caller)
  141. #endif
  142. #ifdef CONFIG_FUNCTION_GRAPH_TRACER
  143. extern void ftrace_graph_caller(void);
  144. extern int ftrace_enable_ftrace_graph_caller(void);
  145. extern int ftrace_disable_ftrace_graph_caller(void);
  146. #else
  147. static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; }
  148. static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; }
  149. #endif
  150. /**
  151. * ftrace_make_nop - convert code into nop
  152. * @mod: module structure if called by module load initialization
  153. * @rec: the mcount call site record
  154. * @addr: the address that the call site should be calling
  155. *
  156. * This is a very sensitive operation and great care needs
  157. * to be taken by the arch. The operation should carefully
  158. * read the location, check to see if what is read is indeed
  159. * what we expect it to be, and then on success of the compare,
  160. * it should write to the location.
  161. *
  162. * The code segment at @rec->ip should be a caller to @addr
  163. *
  164. * Return must be:
  165. * 0 on success
  166. * -EFAULT on error reading the location
  167. * -EINVAL on a failed compare of the contents
  168. * -EPERM on error writing to the location
  169. * Any other value will be considered a failure.
  170. */
  171. extern int ftrace_make_nop(struct module *mod,
  172. struct dyn_ftrace *rec, unsigned long addr);
  173. /**
  174. * ftrace_make_call - convert a nop call site into a call to addr
  175. * @rec: the mcount call site record
  176. * @addr: the address that the call site should call
  177. *
  178. * This is a very sensitive operation and great care needs
  179. * to be taken by the arch. The operation should carefully
  180. * read the location, check to see if what is read is indeed
  181. * what we expect it to be, and then on success of the compare,
  182. * it should write to the location.
  183. *
  184. * The code segment at @rec->ip should be a nop
  185. *
  186. * Return must be:
  187. * 0 on success
  188. * -EFAULT on error reading the location
  189. * -EINVAL on a failed compare of the contents
  190. * -EPERM on error writing to the location
  191. * Any other value will be considered a failure.
  192. */
  193. extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr);
  194. /* May be defined in arch */
  195. extern int ftrace_arch_read_dyn_info(char *buf, int size);
  196. extern int skip_trace(unsigned long ip);
  197. extern void ftrace_release(void *start, unsigned long size);
  198. extern void ftrace_disable_daemon(void);
  199. extern void ftrace_enable_daemon(void);
  200. #else
  201. # define skip_trace(ip) ({ 0; })
  202. # define ftrace_force_update() ({ 0; })
  203. # define ftrace_set_filter(buf, len, reset) do { } while (0)
  204. # define ftrace_disable_daemon() do { } while (0)
  205. # define ftrace_enable_daemon() do { } while (0)
  206. static inline void ftrace_release(void *start, unsigned long size) { }
  207. static inline int register_ftrace_command(struct ftrace_func_command *cmd)
  208. {
  209. return -EINVAL;
  210. }
  211. static inline int unregister_ftrace_command(char *cmd_name)
  212. {
  213. return -EINVAL;
  214. }
  215. #endif /* CONFIG_DYNAMIC_FTRACE */
  216. /* totally disable ftrace - can not re-enable after this */
  217. void ftrace_kill(void);
  218. static inline void tracer_disable(void)
  219. {
  220. #ifdef CONFIG_FUNCTION_TRACER
  221. ftrace_enabled = 0;
  222. #endif
  223. }
  224. /*
  225. * Ftrace disable/restore without lock. Some synchronization mechanism
  226. * must be used to prevent ftrace_enabled to be changed between
  227. * disable/restore.
  228. */
  229. static inline int __ftrace_enabled_save(void)
  230. {
  231. #ifdef CONFIG_FUNCTION_TRACER
  232. int saved_ftrace_enabled = ftrace_enabled;
  233. ftrace_enabled = 0;
  234. return saved_ftrace_enabled;
  235. #else
  236. return 0;
  237. #endif
  238. }
  239. static inline void __ftrace_enabled_restore(int enabled)
  240. {
  241. #ifdef CONFIG_FUNCTION_TRACER
  242. ftrace_enabled = enabled;
  243. #endif
  244. }
  245. #ifdef CONFIG_FRAME_POINTER
  246. /* TODO: need to fix this for ARM */
  247. # define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
  248. # define CALLER_ADDR1 ((unsigned long)__builtin_return_address(1))
  249. # define CALLER_ADDR2 ((unsigned long)__builtin_return_address(2))
  250. # define CALLER_ADDR3 ((unsigned long)__builtin_return_address(3))
  251. # define CALLER_ADDR4 ((unsigned long)__builtin_return_address(4))
  252. # define CALLER_ADDR5 ((unsigned long)__builtin_return_address(5))
  253. # define CALLER_ADDR6 ((unsigned long)__builtin_return_address(6))
  254. #else
  255. # define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
  256. # define CALLER_ADDR1 0UL
  257. # define CALLER_ADDR2 0UL
  258. # define CALLER_ADDR3 0UL
  259. # define CALLER_ADDR4 0UL
  260. # define CALLER_ADDR5 0UL
  261. # define CALLER_ADDR6 0UL
  262. #endif
  263. #ifdef CONFIG_IRQSOFF_TRACER
  264. extern void time_hardirqs_on(unsigned long a0, unsigned long a1);
  265. extern void time_hardirqs_off(unsigned long a0, unsigned long a1);
  266. #else
  267. # define time_hardirqs_on(a0, a1) do { } while (0)
  268. # define time_hardirqs_off(a0, a1) do { } while (0)
  269. #endif
  270. #ifdef CONFIG_PREEMPT_TRACER
  271. extern void trace_preempt_on(unsigned long a0, unsigned long a1);
  272. extern void trace_preempt_off(unsigned long a0, unsigned long a1);
  273. #else
  274. # define trace_preempt_on(a0, a1) do { } while (0)
  275. # define trace_preempt_off(a0, a1) do { } while (0)
  276. #endif
  277. #ifdef CONFIG_TRACING
  278. extern int ftrace_dump_on_oops;
  279. extern void tracing_start(void);
  280. extern void tracing_stop(void);
  281. extern void ftrace_off_permanent(void);
  282. extern void
  283. ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3);
  284. /**
  285. * ftrace_printk - printf formatting in the ftrace buffer
  286. * @fmt: the printf format for printing
  287. *
  288. * Note: __ftrace_printk is an internal function for ftrace_printk and
  289. * the @ip is passed in via the ftrace_printk macro.
  290. *
  291. * This function allows a kernel developer to debug fast path sections
  292. * that printk is not appropriate for. By scattering in various
  293. * printk like tracing in the code, a developer can quickly see
  294. * where problems are occurring.
  295. *
  296. * This is intended as a debugging tool for the developer only.
  297. * Please refrain from leaving ftrace_printks scattered around in
  298. * your code.
  299. */
  300. # define ftrace_printk(fmt...) __ftrace_printk(_THIS_IP_, fmt)
  301. extern int
  302. __ftrace_printk(unsigned long ip, const char *fmt, ...)
  303. __attribute__ ((format (printf, 2, 3)));
  304. # define ftrace_vprintk(fmt, ap) __ftrace_printk(_THIS_IP_, fmt, ap)
  305. extern int
  306. __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);
  307. extern void ftrace_dump(void);
  308. #else
  309. static inline void
  310. ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3) { }
  311. static inline int
  312. ftrace_printk(const char *fmt, ...) __attribute__ ((format (printf, 1, 2)));
  313. static inline void tracing_start(void) { }
  314. static inline void tracing_stop(void) { }
  315. static inline void ftrace_off_permanent(void) { }
  316. static inline int
  317. ftrace_printk(const char *fmt, ...)
  318. {
  319. return 0;
  320. }
  321. static inline int
  322. ftrace_vprintk(const char *fmt, va_list ap)
  323. {
  324. return 0;
  325. }
  326. static inline void ftrace_dump(void) { }
  327. #endif
  328. #ifdef CONFIG_FTRACE_MCOUNT_RECORD
  329. extern void ftrace_init(void);
  330. extern void ftrace_init_module(struct module *mod,
  331. unsigned long *start, unsigned long *end);
  332. #else
  333. static inline void ftrace_init(void) { }
  334. static inline void
  335. ftrace_init_module(struct module *mod,
  336. unsigned long *start, unsigned long *end) { }
  337. #endif
  338. /*
  339. * Structure that defines an entry function trace.
  340. */
  341. struct ftrace_graph_ent {
  342. unsigned long func; /* Current function */
  343. int depth;
  344. };
  345. /*
  346. * Structure that defines a return function trace.
  347. */
  348. struct ftrace_graph_ret {
  349. unsigned long func; /* Current function */
  350. unsigned long long calltime;
  351. unsigned long long rettime;
  352. /* Number of functions that overran the depth limit for current task */
  353. unsigned long overrun;
  354. int depth;
  355. };
  356. #ifdef CONFIG_FUNCTION_GRAPH_TRACER
  357. /*
  358. * Sometimes we don't want to trace a function with the function
  359. * graph tracer but we want them to keep traced by the usual function
  360. * tracer if the function graph tracer is not configured.
  361. */
  362. #define __notrace_funcgraph notrace
  363. /*
  364. * We want to which function is an entrypoint of a hardirq.
  365. * That will help us to put a signal on output.
  366. */
  367. #define __irq_entry __attribute__((__section__(".irqentry.text")))
  368. /* Limits of hardirq entrypoints */
  369. extern char __irqentry_text_start[];
  370. extern char __irqentry_text_end[];
  371. #define FTRACE_RETFUNC_DEPTH 50
  372. #define FTRACE_RETSTACK_ALLOC_SIZE 32
  373. /* Type of the callback handlers for tracing function graph*/
  374. typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */
  375. typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */
  376. extern int register_ftrace_graph(trace_func_graph_ret_t retfunc,
  377. trace_func_graph_ent_t entryfunc);
  378. extern void ftrace_graph_stop(void);
  379. /* The current handlers in use */
  380. extern trace_func_graph_ret_t ftrace_graph_return;
  381. extern trace_func_graph_ent_t ftrace_graph_entry;
  382. extern void unregister_ftrace_graph(void);
  383. extern void ftrace_graph_init_task(struct task_struct *t);
  384. extern void ftrace_graph_exit_task(struct task_struct *t);
  385. static inline int task_curr_ret_stack(struct task_struct *t)
  386. {
  387. return t->curr_ret_stack;
  388. }
  389. static inline void pause_graph_tracing(void)
  390. {
  391. atomic_inc(&current->tracing_graph_pause);
  392. }
  393. static inline void unpause_graph_tracing(void)
  394. {
  395. atomic_dec(&current->tracing_graph_pause);
  396. }
  397. #else
  398. #define __notrace_funcgraph
  399. #define __irq_entry
  400. static inline void ftrace_graph_init_task(struct task_struct *t) { }
  401. static inline void ftrace_graph_exit_task(struct task_struct *t) { }
  402. static inline int task_curr_ret_stack(struct task_struct *tsk)
  403. {
  404. return -1;
  405. }
  406. static inline void pause_graph_tracing(void) { }
  407. static inline void unpause_graph_tracing(void) { }
  408. #endif
  409. #ifdef CONFIG_TRACING
  410. #include <linux/sched.h>
  411. /* flags for current->trace */
  412. enum {
  413. TSK_TRACE_FL_TRACE_BIT = 0,
  414. TSK_TRACE_FL_GRAPH_BIT = 1,
  415. };
  416. enum {
  417. TSK_TRACE_FL_TRACE = 1 << TSK_TRACE_FL_TRACE_BIT,
  418. TSK_TRACE_FL_GRAPH = 1 << TSK_TRACE_FL_GRAPH_BIT,
  419. };
  420. static inline void set_tsk_trace_trace(struct task_struct *tsk)
  421. {
  422. set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
  423. }
  424. static inline void clear_tsk_trace_trace(struct task_struct *tsk)
  425. {
  426. clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
  427. }
  428. static inline int test_tsk_trace_trace(struct task_struct *tsk)
  429. {
  430. return tsk->trace & TSK_TRACE_FL_TRACE;
  431. }
  432. static inline void set_tsk_trace_graph(struct task_struct *tsk)
  433. {
  434. set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
  435. }
  436. static inline void clear_tsk_trace_graph(struct task_struct *tsk)
  437. {
  438. clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
  439. }
  440. static inline int test_tsk_trace_graph(struct task_struct *tsk)
  441. {
  442. return tsk->trace & TSK_TRACE_FL_GRAPH;
  443. }
  444. #endif /* CONFIG_TRACING */
  445. #ifdef CONFIG_HW_BRANCH_TRACER
  446. void trace_hw_branch(u64 from, u64 to);
  447. void trace_hw_branch_oops(void);
  448. #else /* CONFIG_HW_BRANCH_TRACER */
  449. static inline void trace_hw_branch(u64 from, u64 to) {}
  450. static inline void trace_hw_branch_oops(void) {}
  451. #endif /* CONFIG_HW_BRANCH_TRACER */
  452. #endif /* _LINUX_FTRACE_H */