include/linux/unwind.h

   1 #ifndef _LINUX_UNWIND_H
   2 #define _LINUX_UNWIND_H
   3
   4 /*
   5  * Copyright (C) 2002-2006 Novell, Inc.
   6  *      Jan Beulich <jbeulich@novell.com>
   7  * This code is released under version 2 of the GNU GPL.
   8  *
   9  * A simple API for unwinding kernel stacks.  This is used for
  10  * debugging and error reporting purposes.  The kernel doesn't need
  11  * full-blown stack unwinding with all the bells and whistles, so there
  12  * is not much point in implementing the full Dwarf2 unwind API.
  13  */
  14
  15 #include <linux/config.h>
  16
  17 struct module;
  18
  19 #ifdef CONFIG_STACK_UNWIND
  20
  21 #include <asm/unwind.h>
  22
  23 #ifndef ARCH_UNWIND_SECTION_NAME
  24 #define ARCH_UNWIND_SECTION_NAME ".eh_frame"
  25 #endif
  26
  27 /*
  28  * Initialize unwind support.
  29  */
  30 extern void unwind_init(void);
  31
  32 #ifdef CONFIG_MODULES
  33
  34 extern void *unwind_add_table(struct module *,
  35                               const void *table_start,
  36                               unsigned long table_size);
  37
  38 extern void unwind_remove_table(void *handle, int init_only);
  39
  40 #endif
  41
  42 extern int unwind_init_frame_info(struct unwind_frame_info *,
  43                                   struct task_struct *,
  44                                   /*const*/ struct pt_regs *);
  45
  46 /*
  47  * Prepare to unwind a blocked task.
  48  */
  49 extern int unwind_init_blocked(struct unwind_frame_info *,
  50                                struct task_struct *);
  51
  52 /*
  53  * Prepare to unwind the currently running thread.
  54  */
  55 extern int unwind_init_running(struct unwind_frame_info *,
  56                                asmlinkage int (*callback)(struct unwind_frame_info *,
  57                                                           void *arg),
  58                                void *arg);
  59
  60 /*
  61  * Unwind to previous to frame.  Returns 0 if successful, negative
  62  * number in case of an error.
  63  */
  64 extern int unwind(struct unwind_frame_info *);
  65
  66 /*
  67  * Unwind until the return pointer is in user-land (or until an error
  68  * occurs).  Returns 0 if successful, negative number in case of
  69  * error.
  70  */
  71 extern int unwind_to_user(struct unwind_frame_info *);
  72
  73 #else
  74
  75 struct unwind_frame_info {};
  76
  77 static inline void unwind_init(void) {}
  78
  79 #ifdef CONFIG_MODULES
  80
  81 static inline void *unwind_add_table(struct module *mod,
  82                                      const void *table_start,
  83                                      unsigned long table_size)
  84 {
  85         return NULL;
  86 }
  87
  88 #endif
  89
  90 static inline void unwind_remove_table(void *handle, int init_only)
  91 {
  92 }
  93
  94 static inline int unwind_init_frame_info(struct unwind_frame_info *info,
  95                                          struct task_struct *tsk,
  96                                          const struct pt_regs *regs)
  97 {
  98         return -ENOSYS;
  99 }
 100
 101 static inline int unwind_init_blocked(struct unwind_frame_info *info,
 102                                       struct task_struct *tsk)
 103 {
 104         return -ENOSYS;
 105 }
 106
 107 static inline int unwind_init_running(struct unwind_frame_info *info,
 108                                       asmlinkage int (*cb)(struct unwind_frame_info *,
 109                                                            void *arg),
 110                                       void *arg)
 111 {
 112         return -ENOSYS;
 113 }
 114
 115 static inline int unwind(struct unwind_frame_info *info)
 116 {
 117         return -ENOSYS;
 118 }
 119
 120 static inline int unwind_to_user(struct unwind_frame_info *info)
 121 {
 122         return -ENOSYS;
 123 }
 124
 125 #endif
 126
 127 #endif /* _LINUX_UNWIND_H */