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 OPCODE_ESCAPE 0x0f 21 #define SECOND_BYTE_OPCODE_UD1 0xb9 22 #define SECOND_BYTE_OPCODE_UD2 0x0b 23 24 #define BUG_NONE 0xffff 25 #define BUG_UD2 0xfffe 26 #define BUG_UD1 0xfffd 27 #define BUG_UD1_UBSAN 0xfffc 28 29 #ifdef CONFIG_GENERIC_BUG 30 31 #ifdef CONFIG_X86_32 32 # define __BUG_REL(val) ".long " __stringify(val) 33 #else 34 # define __BUG_REL(val) ".long " __stringify(val) " - ." 35 #endif 36 37 #ifdef CONFIG_DEBUG_BUGVERBOSE 38 39 #define _BUG_FLAGS(ins, flags, extra) \ 40 do { \ 41 asm_inline volatile("1:\t" ins "\n" \ 42 ".pushsection __bug_table,\"aw\"\n" \ 43 "2:\t" __BUG_REL(1b) "\t# bug_entry::bug_addr\n" \ 44 "\t" __BUG_REL(%c0) "\t# bug_entry::file\n" \ 45 "\t.word %c1" "\t# bug_entry::line\n" \ 46 "\t.word %c2" "\t# bug_entry::flags\n" \ 47 "\t.org 2b+%c3\n" \ 48 ".popsection\n" \ 49 extra \ 50 : : "i" (__FILE__), "i" (__LINE__), \ 51 "i" (flags), \ 52 "i" (sizeof(struct bug_entry))); \ 53 } while (0) 54 55 #else /* !CONFIG_DEBUG_BUGVERBOSE */ 56 57 #define _BUG_FLAGS(ins, flags, extra) \ 58 do { \ 59 asm_inline volatile("1:\t" ins "\n" \ 60 ".pushsection __bug_table,\"aw\"\n" \ 61 "2:\t" __BUG_REL(1b) "\t# bug_entry::bug_addr\n" \ 62 "\t.word %c0" "\t# bug_entry::flags\n" \ 63 "\t.org 2b+%c1\n" \ 64 ".popsection\n" \ 65 extra \ 66 : : "i" (flags), \ 67 "i" (sizeof(struct bug_entry))); \ 68 } while (0) 69 70 #endif /* CONFIG_DEBUG_BUGVERBOSE */ 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 #define __WARN_FLAGS(flags) \ 93 do { \ 94 __auto_type __flags = BUGFLAG_WARNING|(flags); \ 95 instrumentation_begin(); \ 96 _BUG_FLAGS(ASM_UD2, __flags, ASM_REACHABLE); \ 97 instrumentation_end(); \ 98 } while (0) 99 100 #include <asm-generic/bug.h> 101 102 #endif /* _ASM_X86_BUG_H */ 103