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