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 #include <linux/instrumentation.h> 7 #include <linux/objtool.h> 8 #include <asm/asm.h> 9 10 /* 11 * Despite that some emulators terminate on UD2, we use it for WARN(). 12 */ 13 #define ASM_UD2 _ASM_BYTES(0x0f, 0x0b) 14 #define INSN_UD2 0x0b0f 15 #define LEN_UD2 2 16 17 #define ASM_UDB _ASM_BYTES(0xd6) 18 #define INSN_UDB 0xd6 19 #define LEN_UDB 1 20 21 /* 22 * In clang we have UD1s reporting UBSAN failures on X86, 64 and 32bit. 23 */ 24 #define INSN_ASOP 0x67 25 #define INSN_LOCK 0xf0 26 #define OPCODE_ESCAPE 0x0f 27 #define SECOND_BYTE_OPCODE_UD1 0xb9 28 #define SECOND_BYTE_OPCODE_UD2 0x0b 29 30 #define BUG_NONE 0xffff 31 #define BUG_UD2 0xfffe 32 #define BUG_UD1 0xfffd 33 #define BUG_UD1_UBSAN 0xfffc 34 #define BUG_UDB 0xffd6 35 #define BUG_LOCK 0xfff0 36 37 #ifdef CONFIG_GENERIC_BUG 38 39 #ifdef CONFIG_X86_32 40 # define __BUG_REL(val) ".long " val 41 #else 42 # define __BUG_REL(val) ".long " val " - ." 43 #endif 44 45 #ifdef CONFIG_DEBUG_BUGVERBOSE 46 #define __BUG_ENTRY(file, line, flags) \ 47 "2:\t" __BUG_REL("1b") "\t# bug_entry::bug_addr\n" \ 48 "\t" __BUG_REL(file) "\t# bug_entry::file\n" \ 49 "\t.word " line "\t# bug_entry::line\n" \ 50 "\t.word " flags "\t# bug_entry::flags\n" 51 #else 52 #define __BUG_ENTRY(file, line, flags) \ 53 "2:\t" __BUG_REL("1b") "\t# bug_entry::bug_addr\n" \ 54 "\t.word " flags "\t# bug_entry::flags\n" 55 #endif 56 57 #define _BUG_FLAGS_ASM(ins, file, line, flags, size, extra) \ 58 "1:\t" ins "\n" \ 59 ".pushsection __bug_table,\"aw\"\n" \ 60 __BUG_ENTRY(file, line, flags) \ 61 "\t.org 2b + " size "\n" \ 62 ".popsection\n" \ 63 extra 64 65 #define _BUG_FLAGS(ins, flags, extra) \ 66 do { \ 67 asm_inline volatile(_BUG_FLAGS_ASM(ins, "%c0", \ 68 "%c1", "%c2", "%c3", extra) \ 69 : : "i" (__FILE__), "i" (__LINE__), \ 70 "i" (flags), \ 71 "i" (sizeof(struct bug_entry))); \ 72 } while (0) 73 74 #define ARCH_WARN_ASM(file, line, flags, size) \ 75 _BUG_FLAGS_ASM(ASM_UD2, file, line, flags, size, "") 76 77 #else 78 79 #define _BUG_FLAGS(ins, flags, extra) asm volatile(ins) 80 81 #endif /* CONFIG_GENERIC_BUG */ 82 83 #define HAVE_ARCH_BUG 84 #define BUG() \ 85 do { \ 86 instrumentation_begin(); \ 87 _BUG_FLAGS(ASM_UD2, 0, ""); \ 88 __builtin_unreachable(); \ 89 } while (0) 90 91 /* 92 * This instrumentation_begin() is strictly speaking incorrect; but it 93 * suppresses the complaints from WARN()s in noinstr code. If such a WARN() 94 * were to trigger, we'd rather wreck the machine in an attempt to get the 95 * message out than not know about it. 96 */ 97 98 #define ARCH_WARN_REACHABLE ANNOTATE_REACHABLE(1b) 99 100 #define __WARN_FLAGS(flags) \ 101 do { \ 102 __auto_type __flags = BUGFLAG_WARNING|(flags); \ 103 instrumentation_begin(); \ 104 _BUG_FLAGS(ASM_UD2, __flags, ARCH_WARN_REACHABLE); \ 105 instrumentation_end(); \ 106 } while (0) 107 108 #include <asm-generic/bug.h> 109 110 #endif /* _ASM_X86_BUG_H */ 111