ftrace.h 7.6 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/kallsyms.h>
  9. #ifdef CONFIG_FUNCTION_TRACER
  10. extern int ftrace_enabled;
  11. extern int
  12. ftrace_enable_sysctl(struct ctl_table *table, int write,
  13. struct file *filp, void __user *buffer, size_t *lenp,
  14. loff_t *ppos);
  15. typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip);
  16. struct ftrace_ops {
  17. ftrace_func_t func;
  18. struct ftrace_ops *next;
  19. };
  20. /*
  21. * The ftrace_ops must be a static and should also
  22. * be read_mostly. These functions do modify read_mostly variables
  23. * so use them sparely. Never free an ftrace_op or modify the
  24. * next pointer after it has been registered. Even after unregistering
  25. * it, the next pointer may still be used internally.
  26. */
  27. int register_ftrace_function(struct ftrace_ops *ops);
  28. int unregister_ftrace_function(struct ftrace_ops *ops);
  29. void clear_ftrace_function(void);
  30. extern void ftrace_stub(unsigned long a0, unsigned long a1);
  31. #else /* !CONFIG_FUNCTION_TRACER */
  32. # define register_ftrace_function(ops) do { } while (0)
  33. # define unregister_ftrace_function(ops) do { } while (0)
  34. # define clear_ftrace_function(ops) do { } while (0)
  35. static inline void ftrace_kill_atomic(void) { }
  36. #endif /* CONFIG_FUNCTION_TRACER */
  37. #ifdef CONFIG_DYNAMIC_FTRACE
  38. # define FTRACE_HASHBITS 10
  39. # define FTRACE_HASHSIZE (1<<FTRACE_HASHBITS)
  40. enum {
  41. FTRACE_FL_FREE = (1 << 0),
  42. FTRACE_FL_FAILED = (1 << 1),
  43. FTRACE_FL_FILTER = (1 << 2),
  44. FTRACE_FL_ENABLED = (1 << 3),
  45. FTRACE_FL_NOTRACE = (1 << 4),
  46. FTRACE_FL_CONVERTED = (1 << 5),
  47. FTRACE_FL_FROZEN = (1 << 6),
  48. };
  49. struct dyn_ftrace {
  50. struct hlist_node node;
  51. unsigned long ip; /* address of mcount call-site */
  52. unsigned long flags;
  53. };
  54. int ftrace_force_update(void);
  55. void ftrace_set_filter(unsigned char *buf, int len, int reset);
  56. /* defined in arch */
  57. extern int ftrace_ip_converted(unsigned long ip);
  58. extern unsigned char *ftrace_nop_replace(void);
  59. extern unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr);
  60. extern int ftrace_dyn_arch_init(void *data);
  61. extern int ftrace_mcount_set(unsigned long *data);
  62. extern int ftrace_update_ftrace_func(ftrace_func_t func);
  63. extern void ftrace_caller(void);
  64. extern void ftrace_call(void);
  65. extern void mcount_call(void);
  66. /**
  67. * ftrace_modify_code - modify code segment
  68. * @ip: the address of the code segment
  69. * @old_code: the contents of what is expected to be there
  70. * @new_code: the code to patch in
  71. *
  72. * This is a very sensitive operation and great care needs
  73. * to be taken by the arch. The operation should carefully
  74. * read the location, check to see if what is read is indeed
  75. * what we expect it to be, and then on success of the compare,
  76. * it should write to the location.
  77. *
  78. * Return must be:
  79. * 0 on success
  80. * -EFAULT on error reading the location
  81. * -EINVAL on a failed compare of the contents
  82. * -EPERM on error writing to the location
  83. * Any other value will be considered a failure.
  84. */
  85. extern int ftrace_modify_code(unsigned long ip, unsigned char *old_code,
  86. unsigned char *new_code);
  87. extern int skip_trace(unsigned long ip);
  88. extern void ftrace_release(void *start, unsigned long size);
  89. extern void ftrace_disable_daemon(void);
  90. extern void ftrace_enable_daemon(void);
  91. #else
  92. # define skip_trace(ip) ({ 0; })
  93. # define ftrace_force_update() ({ 0; })
  94. # define ftrace_set_filter(buf, len, reset) do { } while (0)
  95. # define ftrace_disable_daemon() do { } while (0)
  96. # define ftrace_enable_daemon() do { } while (0)
  97. static inline void ftrace_release(void *start, unsigned long size) { }
  98. #endif /* CONFIG_DYNAMIC_FTRACE */
  99. /* totally disable ftrace - can not re-enable after this */
  100. void ftrace_kill(void);
  101. void ftrace_kill_atomic(void);
  102. static inline void tracer_disable(void)
  103. {
  104. #ifdef CONFIG_FUNCTION_TRACER
  105. ftrace_enabled = 0;
  106. #endif
  107. }
  108. /*
  109. * Ftrace disable/restore without lock. Some synchronization mechanism
  110. * must be used to prevent ftrace_enabled to be changed between
  111. * disable/restore.
  112. */
  113. static inline int __ftrace_enabled_save(void)
  114. {
  115. #ifdef CONFIG_FUNCTION_TRACER
  116. int saved_ftrace_enabled = ftrace_enabled;
  117. ftrace_enabled = 0;
  118. return saved_ftrace_enabled;
  119. #else
  120. return 0;
  121. #endif
  122. }
  123. static inline void __ftrace_enabled_restore(int enabled)
  124. {
  125. #ifdef CONFIG_FUNCTION_TRACER
  126. ftrace_enabled = enabled;
  127. #endif
  128. }
  129. #ifdef CONFIG_FRAME_POINTER
  130. /* TODO: need to fix this for ARM */
  131. # define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
  132. # define CALLER_ADDR1 ((unsigned long)__builtin_return_address(1))
  133. # define CALLER_ADDR2 ((unsigned long)__builtin_return_address(2))
  134. # define CALLER_ADDR3 ((unsigned long)__builtin_return_address(3))
  135. # define CALLER_ADDR4 ((unsigned long)__builtin_return_address(4))
  136. # define CALLER_ADDR5 ((unsigned long)__builtin_return_address(5))
  137. # define CALLER_ADDR6 ((unsigned long)__builtin_return_address(6))
  138. #else
  139. # define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
  140. # define CALLER_ADDR1 0UL
  141. # define CALLER_ADDR2 0UL
  142. # define CALLER_ADDR3 0UL
  143. # define CALLER_ADDR4 0UL
  144. # define CALLER_ADDR5 0UL
  145. # define CALLER_ADDR6 0UL
  146. #endif
  147. #ifdef CONFIG_IRQSOFF_TRACER
  148. extern void time_hardirqs_on(unsigned long a0, unsigned long a1);
  149. extern void time_hardirqs_off(unsigned long a0, unsigned long a1);
  150. #else
  151. # define time_hardirqs_on(a0, a1) do { } while (0)
  152. # define time_hardirqs_off(a0, a1) do { } while (0)
  153. #endif
  154. #ifdef CONFIG_PREEMPT_TRACER
  155. extern void trace_preempt_on(unsigned long a0, unsigned long a1);
  156. extern void trace_preempt_off(unsigned long a0, unsigned long a1);
  157. #else
  158. # define trace_preempt_on(a0, a1) do { } while (0)
  159. # define trace_preempt_off(a0, a1) do { } while (0)
  160. #endif
  161. #ifdef CONFIG_TRACING
  162. extern void
  163. ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3);
  164. /**
  165. * ftrace_printk - printf formatting in the ftrace buffer
  166. * @fmt: the printf format for printing
  167. *
  168. * Note: __ftrace_printk is an internal function for ftrace_printk and
  169. * the @ip is passed in via the ftrace_printk macro.
  170. *
  171. * This function allows a kernel developer to debug fast path sections
  172. * that printk is not appropriate for. By scattering in various
  173. * printk like tracing in the code, a developer can quickly see
  174. * where problems are occurring.
  175. *
  176. * This is intended as a debugging tool for the developer only.
  177. * Please refrain from leaving ftrace_printks scattered around in
  178. * your code.
  179. */
  180. # define ftrace_printk(fmt...) __ftrace_printk(_THIS_IP_, fmt)
  181. extern int
  182. __ftrace_printk(unsigned long ip, const char *fmt, ...)
  183. __attribute__ ((format (printf, 2, 3)));
  184. extern void ftrace_dump(void);
  185. #else
  186. static inline void
  187. ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3) { }
  188. static inline int
  189. ftrace_printk(const char *fmt, ...) __attribute__ ((format (printf, 1, 0)));
  190. static inline int
  191. ftrace_printk(const char *fmt, ...)
  192. {
  193. return 0;
  194. }
  195. static inline void ftrace_dump(void) { }
  196. #endif
  197. #ifdef CONFIG_FTRACE_MCOUNT_RECORD
  198. extern void ftrace_init(void);
  199. extern void ftrace_init_module(unsigned long *start, unsigned long *end);
  200. #else
  201. static inline void ftrace_init(void) { }
  202. static inline void
  203. ftrace_init_module(unsigned long *start, unsigned long *end) { }
  204. #endif
  205. struct boot_trace {
  206. pid_t caller;
  207. char func[KSYM_NAME_LEN];
  208. int result;
  209. unsigned long long duration; /* usecs */
  210. ktime_t calltime;
  211. ktime_t rettime;
  212. };
  213. #ifdef CONFIG_BOOT_TRACER
  214. extern void trace_boot(struct boot_trace *it, initcall_t fn);
  215. extern void start_boot_trace(void);
  216. extern void stop_boot_trace(void);
  217. #else
  218. static inline void trace_boot(struct boot_trace *it, initcall_t fn) { }
  219. static inline void start_boot_trace(void) { }
  220. static inline void stop_boot_trace(void) { }
  221. #endif
  222. #endif /* _LINUX_FTRACE_H */