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 struct module;
  16
  17 #ifdef CONFIG_STACK_UNWIND
  18
  19 #include <asm/unwind.h>
  20
  21 #ifndef ARCH_UNWIND_SECTION_NAME
  22 #define ARCH_UNWIND_SECTION_NAME ".eh_frame"
  23 #endif
  24
  25 /*
  26  * Initialize unwind support.
  27  */
  28 extern void unwind_init(void);
  29
  30 #ifdef CONFIG_MODULES
  31
  32 extern void *unwind_add_table(struct module *,
  33                               const void *table_start,
  34                               unsigned long table_size);
  35
  36 extern void unwind_remove_table(void *handle, int init_only);
  37
  38 #endif
  39
  40 extern int unwind_init_frame_info(struct unwind_frame_info *,
  41                                   struct task_struct *,
  42                                   /*const*/ struct pt_regs *);
  43
  44 /*
  45  * Prepare to unwind a blocked task.
  46  */
  47 extern int unwind_init_blocked(struct unwind_frame_info *,
  48                                struct task_struct *);
  49
  50 /*
  51  * Prepare to unwind the currently running thread.
  52  */
  53 extern int unwind_init_running(struct unwind_frame_info *,
  54                                asmlinkage int (*callback)(struct unwind_frame_info *,
  55                                                           void *arg),
  56                                void *arg);
  57
  58 /*
  59  * Unwind to previous to frame.  Returns 0 if successful, negative
  60  * number in case of an error.
  61  */
  62 extern int unwind(struct unwind_frame_info *);
  63
  64 /*
  65  * Unwind until the return pointer is in user-land (or until an error
  66  * occurs).  Returns 0 if successful, negative number in case of
  67  * error.
  68  */
  69 extern int unwind_to_user(struct unwind_frame_info *);
  70
  71 #else
  72
  73 struct unwind_frame_info {};
  74
  75 static inline void unwind_init(void) {}
  76
  77 #ifdef CONFIG_MODULES
  78
  79 static inline void *unwind_add_table(struct module *mod,
  80                                      const void *table_start,
  81                                      unsigned long table_size)
  82 {
  83         return NULL;
  84 }
  85
  86 #endif
  87
  88 static inline void unwind_remove_table(void *handle, int init_only)
  89 {
  90 }
  91
  92 static inline int unwind_init_frame_info(struct unwind_frame_info *info,
  93                                          struct task_struct *tsk,
  94                                          const struct pt_regs *regs)
  95 {
  96         return -ENOSYS;
  97 }
  98
  99 static inline int unwind_init_blocked(struct unwind_frame_info *info,
 100                                       struct task_struct *tsk)
 101 {
 102         return -ENOSYS;
 103 }
 104
 105 static inline int unwind_init_running(struct unwind_frame_info *info,
 106                                       asmlinkage int (*cb)(struct unwind_frame_info *,
 107                                                            void *arg),
 108                                       void *arg)
 109 {
 110         return -ENOSYS;
 111 }
 112
 113 static inline int unwind(struct unwind_frame_info *info)
 114 {
 115         return -ENOSYS;
 116 }
 117
 118 static inline int unwind_to_user(struct unwind_frame_info *info)
 119 {
 120         return -ENOSYS;
 121 }
 122
 123 #endif
 124
 125 #endif /* _LINUX_UNWIND_H */