wrapper/ftrace.h

   1 /* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
   2  *
   3  * wrapper/ftrace.h
   4  *
   5  * wrapper around vmalloc_sync_all. Using KALLSYMS to get its address when
   6  * available, else we need to have a kernel that exports this function to GPL
   7  * modules.
   8  *
   9  * Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  10  */
  11
  12 #ifndef _LTTNG_WRAPPER_FTRACE_H
  13 #define _LTTNG_WRAPPER_FTRACE_H
  14
  15 #include <linux/ftrace.h>
  16 #include <linux/version.h>
  17 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,12,0))
  18 #include <../kernel/trace/trace.h>
  19 #endif
  20
  21 #ifdef CONFIG_KALLSYMS
  22
  23 #include <linux/kallsyms.h>
  24 #include <wrapper/kallsyms.h>
  25
  26 static inline
  27 int wrapper_register_ftrace_function_probe(char *glob,
  28                 struct ftrace_probe_ops *ops, void *data)
  29 {
  30         int (*register_ftrace_function_probe_sym)(char *glob,
  31                         struct ftrace_probe_ops *ops, void *data);
  32
  33         register_ftrace_function_probe_sym = (void *) kallsyms_lookup_funcptr("register_ftrace_function_probe");
  34         if (register_ftrace_function_probe_sym) {
  35                 return register_ftrace_function_probe_sym(glob, ops, data);
  36         } else {
  37                 printk_once(KERN_WARNING "LTTng: register_ftrace_function_probe symbol lookup failed.\n");
  38                 return -EINVAL;
  39         }
  40 }
  41
  42 static inline
  43 void wrapper_unregister_ftrace_function_probe(char *glob,
  44                 struct ftrace_probe_ops *ops, void *data)
  45 {
  46         void (*unregister_ftrace_function_probe_sym)(char *glob,
  47                         struct ftrace_probe_ops *ops, void *data);
  48
  49         unregister_ftrace_function_probe_sym = (void *) kallsyms_lookup_funcptr("unregister_ftrace_function_probe");
  50         if (unregister_ftrace_function_probe_sym) {
  51                 unregister_ftrace_function_probe_sym(glob, ops, data);
  52         } else {
  53                 printk_once(KERN_WARNING "LTTng: unregister_ftrace_function_probe symbol lookup failed.\n");
  54                 WARN_ON(1);
  55         }
  56 }
  57
  58 #else
  59
  60 static inline
  61 int wrapper_register_ftrace_function_probe(char *glob,
  62                 struct ftrace_probe_ops *ops, void *data)
  63 {
  64         return register_ftrace_function_probe(glob, ops, data);
  65 }
  66
  67 static inline
  68 void wrapper_unregister_ftrace_function_probe(char *glob,
  69                 struct ftrace_probe_ops *ops, void *data)
  70 {
  71         return unregister_ftrace_function_probe(glob, ops, data);
  72 }
  73 #endif
  74
  75 #endif /* _LTTNG_WRAPPER_FTRACE_H */