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 #include <linux/version.h>
  30 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,12,0))
  31 #include <../kernel/trace/trace.h>
  32 #endif
  33
  34 #ifdef CONFIG_KALLSYMS
  35
  36 #include <linux/kallsyms.h>
  37 #include <wrapper/kallsyms.h>
  38
  39 static inline
  40 int wrapper_register_ftrace_function_probe(char *glob,
  41                 struct ftrace_probe_ops *ops, void *data)
  42 {
  43         int (*register_ftrace_function_probe_sym)(char *glob,
  44                         struct ftrace_probe_ops *ops, void *data);
  45
  46         register_ftrace_function_probe_sym = (void *) kallsyms_lookup_funcptr("register_ftrace_function_probe");
  47         if (register_ftrace_function_probe_sym) {
  48                 return register_ftrace_function_probe_sym(glob, ops, data);
  49         } else {
  50                 printk_once(KERN_WARNING "LTTng: register_ftrace_function_probe symbol lookup failed.\n");
  51                 return -EINVAL;
  52         }
  53 }
  54
  55 static inline
  56 void wrapper_unregister_ftrace_function_probe(char *glob,
  57                 struct ftrace_probe_ops *ops, void *data)
  58 {
  59         void (*unregister_ftrace_function_probe_sym)(char *glob,
  60                         struct ftrace_probe_ops *ops, void *data);
  61
  62         unregister_ftrace_function_probe_sym = (void *) kallsyms_lookup_funcptr("unregister_ftrace_function_probe");
  63         if (unregister_ftrace_function_probe_sym) {
  64                 unregister_ftrace_function_probe_sym(glob, ops, data);
  65         } else {
  66                 printk_once(KERN_WARNING "LTTng: unregister_ftrace_function_probe symbol lookup failed.\n");
  67                 WARN_ON(1);
  68         }
  69 }
  70
  71 #else
  72
  73 static inline
  74 int wrapper_register_ftrace_function_probe(char *glob,
  75                 struct ftrace_probe_ops *ops, void *data)
  76 {
  77         return register_ftrace_function_probe(glob, ops, data);
  78 }
  79
  80 static inline
  81 void wrapper_unregister_ftrace_function_probe(char *glob,
  82                 struct ftrace_probe_ops *ops, void *data)
  83 {
  84         return unregister_ftrace_function_probe(glob, ops, data);
  85 }
  86 #endif
  87
  88 #endif /* _LTTNG_WRAPPER_FTRACE_H */