include/linux/ftrace.h

   1 #ifndef _LINUX_FTRACE_H
   2 #define _LINUX_FTRACE_H
   3
   4 #ifdef CONFIG_FTRACE
   5
   6 #include <linux/linkage.h>
   7
   8 #define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
   9 #define CALLER_ADDR1 ((unsigned long)__builtin_return_address(1))
  10 #define CALLER_ADDR2 ((unsigned long)__builtin_return_address(2))
  11
  12 typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip);
  13
  14 struct ftrace_ops {
  15         ftrace_func_t     func;
  16         struct ftrace_ops *next;
  17 };
  18
  19 /*
  20  * The ftrace_ops must be a static and should also
  21  * be read_mostly.  These functions do modify read_mostly variables
  22  * so use them sparely. Never free an ftrace_op or modify the
  23  * next pointer after it has been registered. Even after unregistering
  24  * it, the next pointer may still be used internally.
  25  */
  26 int register_ftrace_function(struct ftrace_ops *ops);
  27 int unregister_ftrace_function(struct ftrace_ops *ops);
  28 void clear_ftrace_function(void);
  29
  30 extern void ftrace_stub(unsigned long a0, unsigned long a1);
  31 extern void mcount(void);
  32
  33 #else /* !CONFIG_FTRACE */
  34 # define register_ftrace_function(ops) do { } while (0)
  35 # define unregister_ftrace_function(ops) do { } while (0)
  36 # define clear_ftrace_function(ops) do { } while (0)
  37 #endif /* CONFIG_FTRACE */
  38 #endif /* _LINUX_FTRACE_H */