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) \ 34 do { \ 35 asm_inline 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) \ 51 do { \ 52 asm_inline 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() \ 72 do { \ 73 instrumentation_begin(); \ 74 _BUG_FLAGS(ASM_UD2, 0); \ 75 unreachable(); \ 76 } while (0) 77 78 /* 79 * This instrumentation_begin() is strictly speaking incorrect; but it 80 * suppresses the complaints from WARN()s in noinstr code. If such a WARN() 81 * were to trigger, we'd rather wreck the machine in an attempt to get the 82 * message out than not know about it. 83 */ 84 #define __WARN_FLAGS(flags) \ 85 do { \ 86 instrumentation_begin(); \ 87 _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \ 88 annotate_reachable(); \ 89 instrumentation_end(); \ 90 } while (0) 91 92 #include <asm-generic/bug.h> 93 94 #endif /* _ASM_X86_BUG_H */ 95