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 8 /* 9 * Despite that some emulators terminate on UD2, we use it for WARN(). 10 * 11 * Since various instruction decoders/specs disagree on the encoding of 12 * UD0/UD1. 13 */ 14 15 #define ASM_UD0 ".byte 0x0f, 0xff" /* + ModRM (for Intel) */ 16 #define ASM_UD1 ".byte 0x0f, 0xb9" /* + ModRM */ 17 #define ASM_UD2 ".byte 0x0f, 0x0b" 18 19 #define INSN_UD0 0xff0f 20 #define INSN_UD2 0x0b0f 21 22 #define LEN_UD2 2 23 24 #ifdef CONFIG_GENERIC_BUG 25 26 #ifdef CONFIG_X86_32 27 # define __BUG_REL(val) ".long " __stringify(val) 28 #else 29 # define __BUG_REL(val) ".long " __stringify(val) " - 2b" 30 #endif 31 32 #ifdef CONFIG_DEBUG_BUGVERBOSE 33 34 #define _BUG_FLAGS(ins, flags) \ 35 do { \ 36 asm_inline volatile("1:\t" ins "\n" \ 37 ".pushsection __bug_table,\"aw\"\n" \ 38 "2:\t" __BUG_REL(1b) "\t# bug_entry::bug_addr\n" \ 39 "\t" __BUG_REL(%c0) "\t# bug_entry::file\n" \ 40 "\t.word %c1" "\t# bug_entry::line\n" \ 41 "\t.word %c2" "\t# bug_entry::flags\n" \ 42 "\t.org 2b+%c3\n" \ 43 ".popsection" \ 44 : : "i" (__FILE__), "i" (__LINE__), \ 45 "i" (flags), \ 46 "i" (sizeof(struct bug_entry))); \ 47 } while (0) 48 49 #else /* !CONFIG_DEBUG_BUGVERBOSE */ 50 51 #define _BUG_FLAGS(ins, flags) \ 52 do { \ 53 asm_inline volatile("1:\t" ins "\n" \ 54 ".pushsection __bug_table,\"aw\"\n" \ 55 "2:\t" __BUG_REL(1b) "\t# bug_entry::bug_addr\n" \ 56 "\t.word %c0" "\t# bug_entry::flags\n" \ 57 "\t.org 2b+%c1\n" \ 58 ".popsection" \ 59 : : "i" (flags), \ 60 "i" (sizeof(struct bug_entry))); \ 61 } while (0) 62 63 #endif /* CONFIG_DEBUG_BUGVERBOSE */ 64 65 #else 66 67 #define _BUG_FLAGS(ins, flags) asm volatile(ins) 68 69 #endif /* CONFIG_GENERIC_BUG */ 70 71 #define HAVE_ARCH_BUG 72 #define BUG() \ 73 do { \ 74 instrumentation_begin(); \ 75 _BUG_FLAGS(ASM_UD2, 0); \ 76 unreachable(); \ 77 } while (0) 78 79 /* 80 * This instrumentation_begin() is strictly speaking incorrect; but it 81 * suppresses the complaints from WARN()s in noinstr code. If such a WARN() 82 * were to trigger, we'd rather wreck the machine in an attempt to get the 83 * message out than not know about it. 84 */ 85 #define __WARN_FLAGS(flags) \ 86 do { \ 87 instrumentation_begin(); \ 88 _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \ 89 annotate_reachable(); \ 90 instrumentation_end(); \ 91 } while (0) 92 93 #include <asm-generic/bug.h> 94 95 #endif /* _ASM_X86_BUG_H */ 96