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) \ 35do { \ 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) \ 52do { \ 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() \ 73do { \ 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) \ 86do { \ 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