drivers/staging/lttng/wrapper/ftrace.h

   1 #ifndef _LTTNG_WRAPPER_FTRACE_H
   2 #define _LTTNG_WRAPPER_FTRACE_H
   3
   4 /*
   5  * wrapper/ftrace.h
   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  * Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  12  *
  13  * This library is free software; you can redistribute it and/or
  14  * modify it under the terms of the GNU Lesser General Public
  15  * License as published by the Free Software Foundation; only
  16  * version 2.1 of the License.
  17  *
  18  * This library is distributed in the hope that it will be useful,
  19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  21  * Lesser General Public License for more details.
  22  *
  23  * You should have received a copy of the GNU Lesser General Public
  24  * License along with this library; if not, write to the Free Software
  25  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  26  */
  27
  28 #include <linux/ftrace.h>
  29
  30 #ifdef CONFIG_KALLSYMS
  31
  32 #include <linux/kallsyms.h>
  33 #include "kallsyms.h"
  34
  35 static inline
  36 int wrapper_register_ftrace_function_probe(char *glob,
  37                 struct ftrace_probe_ops *ops, void *data)
  38 {
  39         int (*register_ftrace_function_probe_sym)(char *glob,
  40                         struct ftrace_probe_ops *ops, void *data);
  41
  42         register_ftrace_function_probe_sym = (void *) kallsyms_lookup_funcptr("register_ftrace_function_probe");
  43         if (register_ftrace_function_probe_sym) {
  44                 return register_ftrace_function_probe_sym(glob, ops, data);
  45         } else {
  46                 printk(KERN_WARNING "LTTng: register_ftrace_function_probe symbol lookup failed.\n");
  47                 return -EINVAL;
  48         }
  49 }
  50
  51 static inline
  52 void wrapper_unregister_ftrace_function_probe(char *glob,
  53                 struct ftrace_probe_ops *ops, void *data)
  54 {
  55         void (*unregister_ftrace_function_probe_sym)(char *glob,
  56                         struct ftrace_probe_ops *ops, void *data);
  57
  58         unregister_ftrace_function_probe_sym = (void *) kallsyms_lookup_funcptr("unregister_ftrace_function_probe");
  59         if (unregister_ftrace_function_probe_sym) {
  60                 unregister_ftrace_function_probe_sym(glob, ops, data);
  61         } else {
  62                 printk(KERN_WARNING "LTTng: unregister_ftrace_function_probe symbol lookup failed.\n");
  63                 WARN_ON(1);
  64         }
  65 }
  66
  67 #else
  68
  69 static inline
  70 int wrapper_register_ftrace_function_probe(char *glob,
  71                 struct ftrace_probe_ops *ops, void *data)
  72 {
  73         return register_ftrace_function_probe(glob, ops, data);
  74 }
  75
  76 static inline
  77 void wrapper_unregister_ftrace_function_probe(char *glob,
  78                 struct ftrace_probe_ops *ops, void *data)
  79 {
  80         return unregister_ftrace_function_probe(glob, ops, data);
  81 }
  82 #endif
  83
  84 #endif /* _LTTNG_WRAPPER_FTRACE_H */