arch/arm/include/asm/bug.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _ASMARM_BUG_H
   3 #define _ASMARM_BUG_H
   4
   5 #include <linux/linkage.h>
   6 #include <linux/types.h>
   7 #include <asm/opcodes.h>
   8
   9 /*
  10  * Use a suitable undefined instruction to use for ARM/Thumb2 bug handling.
  11  * We need to be careful not to conflict with those used by other modules and
  12  * the register_undef_hook() system.
  13  */
  14 #ifdef CONFIG_THUMB2_KERNEL
  15 #define BUG_INSTR_VALUE 0xde02
  16 #define BUG_INSTR(__value) __inst_thumb16(__value)
  17 #else
  18 #define BUG_INSTR_VALUE 0xe7f001f2
  19 #define BUG_INSTR(__value) __inst_arm(__value)
  20 #endif
  21
  22
  23 #define BUG() _BUG(__FILE__, __LINE__, BUG_INSTR_VALUE)
  24 #define _BUG(file, line, value) __BUG(file, line, value)
  25
  26 #ifdef CONFIG_DEBUG_BUGVERBOSE
  27
  28 /*
  29  * The extra indirection is to ensure that the __FILE__ string comes through
  30  * OK. Many version of gcc do not support the asm %c parameter which would be
  31  * preferable to this unpleasantness. We use mergeable string sections to
  32  * avoid multiple copies of the string appearing in the kernel image.
  33  */
  34
  35 #define __BUG(__file, __line, __value)                          \
  36 do {                                                            \
  37         asm volatile("1:\t" BUG_INSTR(__value) "\n"  \
  38                 ".pushsection .rodata.str, \"aMS\", %progbits, 1\n" \
  39                 "2:\t.asciz " #__file "\n"                      \
  40                 ".popsection\n"                                 \
  41                 ".pushsection __bug_table,\"aw\"\n"             \
  42                 ".align 2\n"                                    \
  43                 "3:\t.word 1b, 2b\n"                            \
  44                 "\t.hword " #__line ", 0\n"                     \
  45                 ".popsection");                                 \
  46         unreachable();                                          \
  47 } while (0)
  48
  49 #else
  50
  51 #define __BUG(__file, __line, __value)                          \
  52 do {                                                            \
  53         asm volatile(BUG_INSTR(__value) "\n");                  \
  54         unreachable();                                          \
  55 } while (0)
  56 #endif  /* CONFIG_DEBUG_BUGVERBOSE */
  57
  58 #define HAVE_ARCH_BUG
  59
  60 #include <asm-generic/bug.h>
  61
  62 struct pt_regs;
  63 void die(const char *msg, struct pt_regs *regs, int err);
  64
  65 void arm_notify_die(const char *str, struct pt_regs *regs,
  66                 int signo, int si_code, void __user *addr,
  67                 unsigned long err, unsigned long trap);
  68
  69 #ifdef CONFIG_ARM_LPAE
  70 #define FAULT_CODE_ALIGNMENT    33
  71 #define FAULT_CODE_DEBUG        34
  72 #else
  73 #define FAULT_CODE_ALIGNMENT    1
  74 #define FAULT_CODE_DEBUG        2
  75 #endif
  76
  77 void hook_fault_code(int nr, int (*fn)(unsigned long, unsigned int,
  78                                        struct pt_regs *),
  79                      int sig, int code, const char *name);
  80
  81 void hook_ifault_code(int nr, int (*fn)(unsigned long, unsigned int,
  82                                        struct pt_regs *),
  83                      int sig, int code, const char *name);
  84
  85 extern asmlinkage void c_backtrace(unsigned long fp, int pmode);
  86
  87 struct mm_struct;
  88 void show_pte(const char *lvl, struct mm_struct *mm, unsigned long addr);
  89 extern void __show_regs(struct pt_regs *);
  90
  91 #endif