1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0 */ 2*4882a593Smuzhiyun #ifndef _ASM_X86_BUG_H 3*4882a593Smuzhiyun #define _ASM_X86_BUG_H 4*4882a593Smuzhiyun 5*4882a593Smuzhiyun #include <linux/stringify.h> 6*4882a593Smuzhiyun #include <linux/instrumentation.h> 7*4882a593Smuzhiyun 8*4882a593Smuzhiyun /* 9*4882a593Smuzhiyun * Despite that some emulators terminate on UD2, we use it for WARN(). 10*4882a593Smuzhiyun * 11*4882a593Smuzhiyun * Since various instruction decoders/specs disagree on the encoding of 12*4882a593Smuzhiyun * UD0/UD1. 13*4882a593Smuzhiyun */ 14*4882a593Smuzhiyun 15*4882a593Smuzhiyun #define ASM_UD0 ".byte 0x0f, 0xff" /* + ModRM (for Intel) */ 16*4882a593Smuzhiyun #define ASM_UD1 ".byte 0x0f, 0xb9" /* + ModRM */ 17*4882a593Smuzhiyun #define ASM_UD2 ".byte 0x0f, 0x0b" 18*4882a593Smuzhiyun 19*4882a593Smuzhiyun #define INSN_UD0 0xff0f 20*4882a593Smuzhiyun #define INSN_UD2 0x0b0f 21*4882a593Smuzhiyun 22*4882a593Smuzhiyun #define LEN_UD2 2 23*4882a593Smuzhiyun 24*4882a593Smuzhiyun #ifdef CONFIG_GENERIC_BUG 25*4882a593Smuzhiyun 26*4882a593Smuzhiyun #ifdef CONFIG_X86_32 27*4882a593Smuzhiyun # define __BUG_REL(val) ".long " __stringify(val) 28*4882a593Smuzhiyun #else 29*4882a593Smuzhiyun # define __BUG_REL(val) ".long " __stringify(val) " - 2b" 30*4882a593Smuzhiyun #endif 31*4882a593Smuzhiyun 32*4882a593Smuzhiyun #ifdef CONFIG_DEBUG_BUGVERBOSE 33*4882a593Smuzhiyun 34*4882a593Smuzhiyun #define _BUG_FLAGS(ins, flags) \ 35*4882a593Smuzhiyun do { \ 36*4882a593Smuzhiyun asm_inline volatile("1:\t" ins "\n" \ 37*4882a593Smuzhiyun ".pushsection __bug_table,\"aw\"\n" \ 38*4882a593Smuzhiyun "2:\t" __BUG_REL(1b) "\t# bug_entry::bug_addr\n" \ 39*4882a593Smuzhiyun "\t" __BUG_REL(%c0) "\t# bug_entry::file\n" \ 40*4882a593Smuzhiyun "\t.word %c1" "\t# bug_entry::line\n" \ 41*4882a593Smuzhiyun "\t.word %c2" "\t# bug_entry::flags\n" \ 42*4882a593Smuzhiyun "\t.org 2b+%c3\n" \ 43*4882a593Smuzhiyun ".popsection" \ 44*4882a593Smuzhiyun : : "i" (__FILE__), "i" (__LINE__), \ 45*4882a593Smuzhiyun "i" (flags), \ 46*4882a593Smuzhiyun "i" (sizeof(struct bug_entry))); \ 47*4882a593Smuzhiyun } while (0) 48*4882a593Smuzhiyun 49*4882a593Smuzhiyun #else /* !CONFIG_DEBUG_BUGVERBOSE */ 50*4882a593Smuzhiyun 51*4882a593Smuzhiyun #define _BUG_FLAGS(ins, flags) \ 52*4882a593Smuzhiyun do { \ 53*4882a593Smuzhiyun asm_inline volatile("1:\t" ins "\n" \ 54*4882a593Smuzhiyun ".pushsection __bug_table,\"aw\"\n" \ 55*4882a593Smuzhiyun "2:\t" __BUG_REL(1b) "\t# bug_entry::bug_addr\n" \ 56*4882a593Smuzhiyun "\t.word %c0" "\t# bug_entry::flags\n" \ 57*4882a593Smuzhiyun "\t.org 2b+%c1\n" \ 58*4882a593Smuzhiyun ".popsection" \ 59*4882a593Smuzhiyun : : "i" (flags), \ 60*4882a593Smuzhiyun "i" (sizeof(struct bug_entry))); \ 61*4882a593Smuzhiyun } while (0) 62*4882a593Smuzhiyun 63*4882a593Smuzhiyun #endif /* CONFIG_DEBUG_BUGVERBOSE */ 64*4882a593Smuzhiyun 65*4882a593Smuzhiyun #else 66*4882a593Smuzhiyun 67*4882a593Smuzhiyun #define _BUG_FLAGS(ins, flags) asm volatile(ins) 68*4882a593Smuzhiyun 69*4882a593Smuzhiyun #endif /* CONFIG_GENERIC_BUG */ 70*4882a593Smuzhiyun 71*4882a593Smuzhiyun #define HAVE_ARCH_BUG 72*4882a593Smuzhiyun #define BUG() \ 73*4882a593Smuzhiyun do { \ 74*4882a593Smuzhiyun instrumentation_begin(); \ 75*4882a593Smuzhiyun _BUG_FLAGS(ASM_UD2, 0); \ 76*4882a593Smuzhiyun unreachable(); \ 77*4882a593Smuzhiyun } while (0) 78*4882a593Smuzhiyun 79*4882a593Smuzhiyun /* 80*4882a593Smuzhiyun * This instrumentation_begin() is strictly speaking incorrect; but it 81*4882a593Smuzhiyun * suppresses the complaints from WARN()s in noinstr code. If such a WARN() 82*4882a593Smuzhiyun * were to trigger, we'd rather wreck the machine in an attempt to get the 83*4882a593Smuzhiyun * message out than not know about it. 84*4882a593Smuzhiyun */ 85*4882a593Smuzhiyun #define __WARN_FLAGS(flags) \ 86*4882a593Smuzhiyun do { \ 87*4882a593Smuzhiyun instrumentation_begin(); \ 88*4882a593Smuzhiyun _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \ 89*4882a593Smuzhiyun annotate_reachable(); \ 90*4882a593Smuzhiyun instrumentation_end(); \ 91*4882a593Smuzhiyun } while (0) 92*4882a593Smuzhiyun 93*4882a593Smuzhiyun #include <asm-generic/bug.h> 94*4882a593Smuzhiyun 95*4882a593Smuzhiyun #endif /* _ASM_X86_BUG_H */ 96