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