LXR linux/arch/x86/include/asm/bug.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _ASM_X86_BUG_H
   3#define _ASM_X86_BUG_H
   4
   5#include <linux/stringify.h>
   6
   7/*
   8 * Despite that some emulators terminate on UD2, we use it for WARN().
   9 *
  10 * Since various instruction decoders/specs disagree on the encoding of
  11 * UD0/UD1.
  12 */
  13
  14#define ASM_UD0         ".byte 0x0f, 0xff" /* + ModRM (for Intel) */
  15#define ASM_UD1         ".byte 0x0f, 0xb9" /* + ModRM */
  16#define ASM_UD2         ".byte 0x0f, 0x0b"
  17
  18#define INSN_UD0        0xff0f
  19#define INSN_UD2        0x0b0f
  20
  21#define LEN_UD2         2
  22
  23#ifdef CONFIG_GENERIC_BUG
  24
  25#ifdef CONFIG_X86_32
  26# define __BUG_REL(val) ".long " __stringify(val)
  27#else
  28# define __BUG_REL(val) ".long " __stringify(val) " - 2b"
  29#endif
  30
  31#ifdef CONFIG_DEBUG_BUGVERBOSE
  32
  33#define _BUG_FLAGS(ins, flags)                                          \
  34do {                                                                    \
  35        asm volatile("1:\t" ins "\n"                                    \
  36                     ".pushsection __bug_table,\"aw\"\n"                \
  37                     "2:\t" __BUG_REL(1b) "\t# bug_entry::bug_addr\n"   \
  38                     "\t"  __BUG_REL(%c0) "\t# bug_entry::file\n"       \
  39                     "\t.word %c1"        "\t# bug_entry::line\n"       \
  40                     "\t.word %c2"        "\t# bug_entry::flags\n"      \
  41                     "\t.org 2b+%c3\n"                                  \
  42                     ".popsection"                                      \
  43                     : : "i" (__FILE__), "i" (__LINE__),                \
  44                         "i" (flags),                                   \
  45                         "i" (sizeof(struct bug_entry)));               \
  46} while (0)
  47
  48#else /* !CONFIG_DEBUG_BUGVERBOSE */
  49
  50#define _BUG_FLAGS(ins, flags)                                          \
  51do {                                                                    \
  52        asm volatile("1:\t" ins "\n"                                    \
  53                     ".pushsection __bug_table,\"aw\"\n"                \
  54                     "2:\t" __BUG_REL(1b) "\t# bug_entry::bug_addr\n"   \
  55                     "\t.word %c0"        "\t# bug_entry::flags\n"      \
  56                     "\t.org 2b+%c1\n"                                  \
  57                     ".popsection"                                      \
  58                     : : "i" (flags),                                   \
  59                         "i" (sizeof(struct bug_entry)));               \
  60} while (0)
  61
  62#endif /* CONFIG_DEBUG_BUGVERBOSE */
  63
  64#else
  65
  66#define _BUG_FLAGS(ins, flags)  asm volatile(ins)
  67
  68#endif /* CONFIG_GENERIC_BUG */
  69
  70#define HAVE_ARCH_BUG
  71#define BUG()                                                   \
  72do {                                                            \
  73        _BUG_FLAGS(ASM_UD2, 0);                                 \
  74        unreachable();                                          \
  75} while (0)
  76
  77#define __WARN_FLAGS(flags)                                     \
  78do {                                                            \
  79        _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags));           \
  80        annotate_reachable();                                   \
  81} while (0)
  82
  83#include <asm-generic/bug.h>
  84
  85#endif /* _ASM_X86_BUG_H */
  86