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_UD1 0xfffe 26 #define BUG_UD2 0xfffd 27 28 #ifdef CONFIG_GENERIC_BUG 29 30 #ifdef CONFIG_X86_32 31 # define __BUG_REL(val) ".long " __stringify(val) 32 #else 33 # define __BUG_REL(val) ".long " __stringify(val) " - ." 34 #endif 35 36 #ifdef CONFIG_DEBUG_BUGVERBOSE 37 38 #define _BUG_FLAGS(ins, flags, extra) \ 39 do { \ 40 asm_inline volatile("1:\t" ins "\n" \ 41 ".pushsection __bug_table,\"aw\"\n" \ 42 "2:\t" __BUG_REL(1b) "\t# bug_entry::bug_addr\n" \ 43 "\t" __BUG_REL(%c0) "\t# bug_entry::file\n" \ 44 "\t.word %c1" "\t# bug_entry::line\n" \ 45 "\t.word %c2" "\t# bug_entry::flags\n" \ 46 "\t.org 2b+%c3\n" \ 47 ".popsection\n" \ 48 extra \ 49 : : "i" (__FILE__), "i" (__LINE__), \ 50 "i" (flags), \ 51 "i" (sizeof(struct bug_entry))); \ 52 } while (0) 53 54 #else /* !CONFIG_DEBUG_BUGVERBOSE */ 55 56 #define _BUG_FLAGS(ins, flags, extra) \ 57 do { \ 58 asm_inline volatile("1:\t" ins "\n" \ 59 ".pushsection __bug_table,\"aw\"\n" \ 60 "2:\t" __BUG_REL(1b) "\t# bug_entry::bug_addr\n" \ 61 "\t.word %c0" "\t# bug_entry::flags\n" \ 62 "\t.org 2b+%c1\n" \ 63 ".popsection\n" \ 64 extra \ 65 : : "i" (flags), \ 66 "i" (sizeof(struct bug_entry))); \ 67 } while (0) 68 69 #endif /* CONFIG_DEBUG_BUGVERBOSE */ 70 71 #else 72 73 #define _BUG_FLAGS(ins, flags, extra) asm volatile(ins) 74 75 #endif /* CONFIG_GENERIC_BUG */ 76 77 #define HAVE_ARCH_BUG 78 #define BUG() \ 79 do { \ 80 instrumentation_begin(); \ 81 _BUG_FLAGS(ASM_UD2, 0, ""); \ 82 __builtin_unreachable(); \ 83 } while (0) 84 85 /* 86 * This instrumentation_begin() is strictly speaking incorrect; but it 87 * suppresses the complaints from WARN()s in noinstr code. If such a WARN() 88 * were to trigger, we'd rather wreck the machine in an attempt to get the 89 * message out than not know about it. 90 */ 91 #define __WARN_FLAGS(flags) \ 92 do { \ 93 __auto_type __flags = BUGFLAG_WARNING|(flags); \ 94 instrumentation_begin(); \ 95 _BUG_FLAGS(ASM_UD2, __flags, ASM_REACHABLE); \ 96 instrumentation_end(); \ 97 } while (0) 98 99 #include <asm-generic/bug.h> 100 101 #endif /* _ASM_X86_BUG_H */ 102