diff options
Diffstat (limited to 'arch/x86/include/asm/bug.h')
| -rw-r--r-- | arch/x86/include/asm/bug.h | 78 |
1 files changed, 60 insertions, 18 deletions
diff --git a/arch/x86/include/asm/bug.h b/arch/x86/include/asm/bug.h index ba38ebbaced3..4fde330c44b7 100644 --- a/arch/x86/include/asm/bug.h +++ b/arch/x86/include/asm/bug.h @@ -1,36 +1,78 @@ #ifndef _ASM_X86_BUG_H #define _ASM_X86_BUG_H -#define HAVE_ARCH_BUG +#include <linux/stringify.h> -#ifdef CONFIG_DEBUG_BUGVERBOSE +/* + * Since some emulators terminate on UD2, we cannot use it for WARN. + * Since various instruction decoders disagree on the length of UD1, + * we cannot use it either. So use UD0 for WARN. + * + * (binutils knows about "ud1" but {en,de}codes it as 2 bytes, whereas + * our kernel decoder thinks it takes a ModRM byte, which seems consistent + * with various things like the Intel SDM instruction encoding rules) + */ + +#define ASM_UD0 ".byte 0x0f, 0xff" +#define ASM_UD1 ".byte 0x0f, 0xb9" /* + ModRM */ +#define ASM_UD2 ".byte 0x0f, 0x0b" + +#define INSN_UD0 0xff0f +#define INSN_UD2 0x0b0f + +#define LEN_UD0 2 + +#ifdef CONFIG_GENERIC_BUG +#define HAVE_ARCH_BUG #ifdef CONFIG_X86_32 -# define __BUG_C0 "2:\t.long 1b, %c0\n" +# define __BUG_REL(val) ".long " __stringify(val) #else -# define __BUG_C0 "2:\t.long 1b - 2b, %c0 - 2b\n" +# define __BUG_REL(val) ".long " __stringify(val) " - 2b" #endif -#define BUG() \ -do { \ - asm volatile("1:\tud2\n" \ - ".pushsection __bug_table,\"a\"\n" \ - __BUG_C0 \ - "\t.word %c1, 0\n" \ - "\t.org 2b+%c2\n" \ - ".popsection" \ - : : "i" (__FILE__), "i" (__LINE__), \ - "i" (sizeof(struct bug_entry))); \ - unreachable(); \ +#ifdef CONFIG_DEBUG_BUGVERBOSE + +#define _BUG_FLAGS(ins, flags) \ +do { \ + asm volatile("1:\t" ins "\n" \ + ".pushsection __bug_table,\"a\"\n" \ + "2:\t" __BUG_REL(1b) "\t# bug_entry::bug_addr\n" \ + "\t" __BUG_REL(%c0) "\t# bug_entry::file\n" \ + "\t.word %c1" "\t# bug_entry::line\n" \ + "\t.word %c2" "\t# bug_entry::flags\n" \ + "\t.org 2b+%c3\n" \ + ".popsection" \ + : : "i" (__FILE__), "i" (__LINE__), \ + "i" (flags), \ + "i" (sizeof(struct bug_entry))); \ } while (0) -#else +#else /* !CONFIG_DEBUG_BUGVERBOSE */ + +#define _BUG_FLAGS(ins, flags) \ +do { \ + asm volatile("1:\t" ins "\n" \ + ".pushsection __bug_table,\"a\"\n" \ + "2:\t" __BUG_REL(1b) "\t# bug_entry::bug_addr\n" \ + "\t.word %c0" "\t# bug_entry::flags\n" \ + "\t.org 2b+%c1\n" \ + ".popsection" \ + : : "i" (flags), \ + "i" (sizeof(struct bug_entry))); \ +} while (0) + +#endif /* CONFIG_DEBUG_BUGVERBOSE */ + #define BUG() \ do { \ - asm volatile("ud2"); \ + _BUG_FLAGS(ASM_UD2, 0); \ unreachable(); \ } while (0) -#endif + +#define __WARN_TAINT(taint) _BUG_FLAGS(ASM_UD0, BUGFLAG_TAINT(taint)) + +#endif /* CONFIG_GENERIC_BUG */ #include <asm-generic/bug.h> |