wrapper/ftrace.h

   1 #ifndef _LTTNG_WRAPPER_FTRACE_H
   2 #define _LTTNG_WRAPPER_FTRACE_H
   3
   4 /*
   5  * Copyright (C) 2011 Mathieu Desnoyers (mathieu.desnoyers@efficios.com)
   6  *
   7  * wrapper around vmalloc_sync_all. Using KALLSYMS to get its address when
   8  * available, else we need to have a kernel that exports this function to GPL
   9  * modules.
  10  *
  11  * Dual LGPL v2.1/GPL v2 license.
  12  */
  13
  14 #include <linux/ftrace.h>
  15
  16 #ifdef CONFIG_KALLSYMS
  17
  18 #include <linux/kallsyms.h>
  19 #include "kallsyms.h"
  20
  21 static inline
  22 int wrapper_register_ftrace_function_probe(char *glob,
  23                 struct ftrace_probe_ops *ops, void *data)
  24 {
  25         int (*register_ftrace_function_probe_sym)(char *glob,
  26                         struct ftrace_probe_ops *ops, void *data);
  27
  28         register_ftrace_function_probe_sym = (void *) kallsyms_lookup_funcptr("register_ftrace_function_probe");
  29         if (register_ftrace_function_probe_sym) {
  30                 return register_ftrace_function_probe_sym(glob, ops, data);
  31         } else {
  32                 printk(KERN_WARNING "LTTng: register_ftrace_function_probe symbol lookup failed.\n");
  33                 return -EINVAL;
  34         }
  35 }
  36
  37 static inline
  38 void wrapper_unregister_ftrace_function_probe(char *glob,
  39                 struct ftrace_probe_ops *ops, void *data)
  40 {
  41         void (*unregister_ftrace_function_probe_sym)(char *glob,
  42                         struct ftrace_probe_ops *ops, void *data);
  43
  44         unregister_ftrace_function_probe_sym = (void *) kallsyms_lookup_funcptr("unregister_ftrace_function_probe");
  45         if (unregister_ftrace_function_probe_sym) {
  46                 unregister_ftrace_function_probe_sym(glob, ops, data);
  47         } else {
  48                 printk(KERN_WARNING "LTTng: unregister_ftrace_function_probe symbol lookup failed.\n");
  49                 WARN_ON(1);
  50         }
  51 }
  52
  53 #else
  54
  55 static inline
  56 int wrapper_register_ftrace_function_probe(char *glob,
  57                 struct ftrace_probe_ops *ops, void *data)
  58 {
  59         return register_ftrace_function_probe(glob, ops, data);
  60 }
  61
  62 static inline
  63 void wrapper_unregister_ftrace_function_probe(char *glob,
  64                 struct ftrace_probe_ops *ops, void *data)
  65 {
  66         return unregister_ftrace_function_probe(glob, ops, data);
  67 }
  68 #endif
  69
  70 #endif /* _LTTNG_WRAPPER_FTRACE_H */