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 #ifndef __ASSEMBLY__
   8
   9 /*
  10  * Despite that some emulators terminate on UD2, we use it for WARN().
  11  *
  12  * Since various instruction decoders/specs disagree on the encoding of
  13  * UD0/UD1.
  14  */
  15
  16 #define ASM_UD0         ".byte 0x0f, 0xff" /* + ModRM (for Intel) */
  17 #define ASM_UD1         ".byte 0x0f, 0xb9" /* + ModRM */
  18 #define ASM_UD2         ".byte 0x0f, 0x0b"
  19
  20 #define INSN_UD0        0xff0f
  21 #define INSN_UD2        0x0b0f
  22
  23 #define LEN_UD2         2
  24
  25 #define _BUG_FLAGS(ins, flags)                                          \
  26 do {                                                                    \
  27         asm volatile("ASM_BUG ins=\"" ins "\" file=%c0 line=%c1 "       \
  28                      "flags=%c2 size=%c3"                               \
  29                      : : "i" (__FILE__), "i" (__LINE__),                \
  30                          "i" (flags),                                   \
  31                          "i" (sizeof(struct bug_entry)));               \
  32 } while (0)
  33
  34 #define HAVE_ARCH_BUG
  35 #define BUG()                                                   \
  36 do {                                                            \
  37         _BUG_FLAGS(ASM_UD2, 0);                                 \
  38         unreachable();                                          \
  39 } while (0)
  40
  41 #define __WARN_FLAGS(flags)                                     \
  42 do {                                                            \
  43         _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags));           \
  44         annotate_reachable();                                   \
  45 } while (0)
  46
  47 #include <asm-generic/bug.h>
  48
  49 #else /* __ASSEMBLY__ */
  50
  51 #ifdef CONFIG_GENERIC_BUG
  52
  53 #ifdef CONFIG_X86_32
  54 .macro __BUG_REL val:req
  55         .long \val
  56 .endm
  57 #else
  58 .macro __BUG_REL val:req
  59         .long \val - 2b
  60 .endm
  61 #endif
  62
  63 #ifdef CONFIG_DEBUG_BUGVERBOSE
  64
  65 .macro ASM_BUG ins:req file:req line:req flags:req size:req
  66 1:      \ins
  67         .pushsection __bug_table,"aw"
  68 2:      __BUG_REL val=1b        # bug_entry::bug_addr
  69         __BUG_REL val=\file     # bug_entry::file
  70         .word \line             # bug_entry::line
  71         .word \flags            # bug_entry::flags
  72         .org 2b+\size
  73         .popsection
  74 .endm
  75
  76 #else /* !CONFIG_DEBUG_BUGVERBOSE */
  77
  78 .macro ASM_BUG ins:req file:req line:req flags:req size:req
  79 1:      \ins
  80         .pushsection __bug_table,"aw"
  81 2:      __BUG_REL val=1b        # bug_entry::bug_addr
  82         .word \flags            # bug_entry::flags
  83         .org 2b+\size
  84         .popsection
  85 .endm
  86
  87 #endif /* CONFIG_DEBUG_BUGVERBOSE */
  88
  89 #else /* CONFIG_GENERIC_BUG */
  90
  91 .macro ASM_BUG ins:req file:req line:req flags:req size:req
  92         \ins
  93 .endm
  94
  95 #endif /* CONFIG_GENERIC_BUG */
  96
  97 #endif /* __ASSEMBLY__ */
  98
  99 #endif /* _ASM_X86_BUG_H */