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 #ifdef CONFIG_GENERIC_BUG 17 18 #ifdef CONFIG_X86_32 19 # define __BUG_REL(val) ".long " __stringify(val) 20 #else 21 # define __BUG_REL(val) ".long " __stringify(val) " - ." 22 #endif 23 24 #ifdef CONFIG_DEBUG_BUGVERBOSE 25 26 #define _BUG_FLAGS(ins, flags, extra) \ 27 do { \ 28 asm_inline volatile("1:\t" ins "\n" \ 29 ".pushsection __bug_table,\"aw\"\n" \ 30 "2:\t" __BUG_REL(1b) "\t# bug_entry::bug_addr\n" \ 31 "\t" __BUG_REL(%c0) "\t# bug_entry::file\n" \ 32 "\t.word %c1" "\t# bug_entry::line\n" \ 33 "\t.word %c2" "\t# bug_entry::flags\n" \ 34 "\t.org 2b+%c3\n" \ 35 ".popsection\n" \ 36 extra \ 37 : : "i" (__FILE__), "i" (__LINE__), \ 38 "i" (flags), \ 39 "i" (sizeof(struct bug_entry))); \ 40 } while (0) 41 42 #else /* !CONFIG_DEBUG_BUGVERBOSE */ 43 44 #define _BUG_FLAGS(ins, flags, extra) \ 45 do { \ 46 asm_inline volatile("1:\t" ins "\n" \ 47 ".pushsection __bug_table,\"aw\"\n" \ 48 "2:\t" __BUG_REL(1b) "\t# bug_entry::bug_addr\n" \ 49 "\t.word %c0" "\t# bug_entry::flags\n" \ 50 "\t.org 2b+%c1\n" \ 51 ".popsection\n" \ 52 extra \ 53 : : "i" (flags), \ 54 "i" (sizeof(struct bug_entry))); \ 55 } while (0) 56 57 #endif /* CONFIG_DEBUG_BUGVERBOSE */ 58 59 #else 60 61 #define _BUG_FLAGS(ins, flags, extra) asm volatile(ins) 62 63 #endif /* CONFIG_GENERIC_BUG */ 64 65 #define HAVE_ARCH_BUG 66 #define BUG() \ 67 do { \ 68 instrumentation_begin(); \ 69 _BUG_FLAGS(ASM_UD2, 0, ""); \ 70 __builtin_unreachable(); \ 71 } while (0) 72 73 /* 74 * This instrumentation_begin() is strictly speaking incorrect; but it 75 * suppresses the complaints from WARN()s in noinstr code. If such a WARN() 76 * were to trigger, we'd rather wreck the machine in an attempt to get the 77 * message out than not know about it. 78 */ 79 #define __WARN_FLAGS(flags) \ 80 do { \ 81 __auto_type __flags = BUGFLAG_WARNING|(flags); \ 82 instrumentation_begin(); \ 83 _BUG_FLAGS(ASM_UD2, __flags, ASM_REACHABLE); \ 84 instrumentation_end(); \ 85 } while (0) 86 87 #include <asm-generic/bug.h> 88 89 #endif /* _ASM_X86_BUG_H */ 90