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 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 extern int unwind_init_frame_info(struct unwind_frame_info *,
  39                                   struct task_struct *,
  40                                   /*const*/ struct pt_regs *);
  41
  42 /*
  43  * Prepare to unwind a blocked task.
  44  */
  45 extern int unwind_init_blocked(struct unwind_frame_info *,
  46                                struct task_struct *);
  47
  48 /*
  49  * Prepare to unwind the currently running thread.
  50  */
  51 extern int unwind_init_running(struct unwind_frame_info *,
  52                                asmlinkage void (*callback)(struct unwind_frame_info *,
  53                                                            void *arg),
  54                                void *arg);
  55
  56 /*
  57  * Unwind to previous to frame.  Returns 0 if successful, negative
  58  * number in case of an error.
  59  */
  60 extern int unwind(struct unwind_frame_info *);
  61
  62 /*
  63  * Unwind until the return pointer is in user-land (or until an error
  64  * occurs).  Returns 0 if successful, negative number in case of
  65  * error.
  66  */
  67 extern int unwind_to_user(struct unwind_frame_info *);
  68
  69 #else
  70
  71 struct unwind_frame_info {};
  72
  73 static inline void unwind_init(void) {}
  74
  75 static inline void *unwind_add_table(struct module *mod,
  76                                      const void *table_start,
  77                                      unsigned long table_size)
  78 {
  79         return NULL;
  80 }
  81
  82 static inline void unwind_remove_table(void *handle, int init_only)
  83 {
  84 }
  85
  86 static inline int unwind_init_frame_info(struct unwind_frame_info *info,
  87                                          struct task_struct *tsk,
  88                                          const struct pt_regs *regs)
  89 {
  90         return -ENOSYS;
  91 }
  92
  93 static inline int unwind_init_blocked(struct unwind_frame_info *info,
  94                                       struct task_struct *tsk)
  95 {
  96         return -ENOSYS;
  97 }
  98
  99 static inline int unwind_init_running(struct unwind_frame_info *info,
 100                                       asmlinkage void (*cb)(struct unwind_frame_info *,
 101                                                             void *arg),
 102                                       void *arg)
 103 {
 104         return -ENOSYS;
 105 }
 106
 107 static inline int unwind(struct unwind_frame_info *info)
 108 {
 109         return -ENOSYS;
 110 }
 111
 112 static inline int unwind_to_user(struct unwind_frame_info *info)
 113 {
 114         return -ENOSYS;
 115 }
 116
 117 #endif
 118
 119 #endif /* _LINUX_UNWIND_H */