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 extern void unwind_setup(void);
  30
  31 #ifdef CONFIG_MODULES
  32
  33 extern void *unwind_add_table(struct module *,
  34                               const void *table_start,
  35                               unsigned long table_size);
  36
  37 extern void unwind_remove_table(void *handle, int init_only);
  38
  39 #endif
  40
  41 extern int unwind_init_frame_info(struct unwind_frame_info *,
  42                                   struct task_struct *,
  43                                   /*const*/ struct pt_regs *);
  44
  45 /*
  46  * Prepare to unwind a blocked task.
  47  */
  48 extern int unwind_init_blocked(struct unwind_frame_info *,
  49                                struct task_struct *);
  50
  51 /*
  52  * Prepare to unwind the currently running thread.
  53  */
  54 extern int unwind_init_running(struct unwind_frame_info *,
  55                                asmlinkage int (*callback)(struct unwind_frame_info *,
  56                                                           void *arg),
  57                                void *arg);
  58
  59 /*
  60  * Unwind to previous to frame.  Returns 0 if successful, negative
  61  * number in case of an error.
  62  */
  63 extern int unwind(struct unwind_frame_info *);
  64
  65 /*
  66  * Unwind until the return pointer is in user-land (or until an error
  67  * occurs).  Returns 0 if successful, negative number in case of
  68  * error.
  69  */
  70 extern int unwind_to_user(struct unwind_frame_info *);
  71
  72 #else
  73
  74 struct unwind_frame_info {};
  75
  76 static inline void unwind_init(void) {}
  77 static inline void unwind_setup(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 */