1 #ifndef _ASM_X86_BUG_H 2 #define _ASM_X86_BUG_H 3 4 #include <linux/stringify.h> 5 6 /* 7 * Since some emulators terminate on UD2, we cannot use it for WARN. 8 * Since various instruction decoders disagree on the length of UD1, 9 * we cannot use it either. So use UD0 for WARN. 10 * 11 * (binutils knows about "ud1" but {en,de}codes it as 2 bytes, whereas 12 * our kernel decoder thinks it takes a ModRM byte, which seems consistent 13 * with various things like the Intel SDM instruction encoding rules) 14 */ 15 16 #define ASM_UD0 ".byte 0x0f, 0xff" 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_UD0 2 24 25 #ifdef CONFIG_GENERIC_BUG 26 27 #ifdef CONFIG_X86_32 28 # define __BUG_REL(val) ".long " __stringify(val) 29 #else 30 # define __BUG_REL(val) ".long " __stringify(val) " - 2b" 31 #endif 32 33 #ifdef CONFIG_DEBUG_BUGVERBOSE 34 35 #define _BUG_FLAGS(ins, flags) \ 36 do { \ 37 asm volatile("1:\t" ins "\n" \ 38 ".pushsection __bug_table,\"a\"\n" \ 39 "2:\t" __BUG_REL(1b) "\t# bug_entry::bug_addr\n" \ 40 "\t" __BUG_REL(%c0) "\t# bug_entry::file\n" \ 41 "\t.word %c1" "\t# bug_entry::line\n" \ 42 "\t.word %c2" "\t# bug_entry::flags\n" \ 43 "\t.org 2b+%c3\n" \ 44 ".popsection" \ 45 : : "i" (__FILE__), "i" (__LINE__), \ 46 "i" (flags), \ 47 "i" (sizeof(struct bug_entry))); \ 48 } while (0) 49 50 #else /* !CONFIG_DEBUG_BUGVERBOSE */ 51 52 #define _BUG_FLAGS(ins, flags) \ 53 do { \ 54 asm volatile("1:\t" ins "\n" \ 55 ".pushsection __bug_table,\"a\"\n" \ 56 "2:\t" __BUG_REL(1b) "\t# bug_entry::bug_addr\n" \ 57 "\t.word %c0" "\t# bug_entry::flags\n" \ 58 "\t.org 2b+%c1\n" \ 59 ".popsection" \ 60 : : "i" (flags), \ 61 "i" (sizeof(struct bug_entry))); \ 62 } while (0) 63 64 #endif /* CONFIG_DEBUG_BUGVERBOSE */ 65 66 #else 67 68 #define _BUG_FLAGS(ins, flags) asm volatile(ins) 69 70 #endif /* CONFIG_GENERIC_BUG */ 71 72 #define HAVE_ARCH_BUG 73 #define BUG() \ 74 do { \ 75 _BUG_FLAGS(ASM_UD2, 0); \ 76 unreachable(); \ 77 } while (0) 78 79 #define __WARN_FLAGS(flags) _BUG_FLAGS(ASM_UD0, BUGFLAG_WARNING|(flags)) 80 81 #include <asm-generic/bug.h> 82 83 #endif /* _ASM_X86_BUG_H */ 84