| 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
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| 2 | #ifndef _ASM_X86_BUG_H |
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| 3 | #define _ASM_X86_BUG_H |
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| 4 | |
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| 5 | #include <linux/stringify.h> |
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| 6 | #include <linux/instrumentation.h> |
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| 7 | #include <linux/objtool.h> |
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| 8 | |
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| 9 | /* |
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| 10 | * Despite that some emulators terminate on UD2, we use it for WARN(). |
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| 11 | */ |
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| 12 | #define ASM_UD2 ".byte 0x0f, 0x0b" |
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| 13 | #define INSN_UD2 0x0b0f |
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| 14 | #define LEN_UD2 2 |
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| 15 | |
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| 16 | /* |
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| 17 | * In clang we have UD1s reporting UBSAN failures on X86, 64 and 32bit. |
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| 18 | */ |
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| 19 | #define INSN_ASOP 0x67 |
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| 20 | #define INSN_LOCK 0xf0 |
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| 21 | #define OPCODE_ESCAPE 0x0f |
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| 22 | #define SECOND_BYTE_OPCODE_UD1 0xb9 |
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| 23 | #define SECOND_BYTE_OPCODE_UD2 0x0b |
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| 24 | |
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| 25 | #define BUG_NONE 0xffff |
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| 26 | #define BUG_UD2 0xfffe |
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| 27 | #define BUG_UD1 0xfffd |
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| 28 | #define BUG_UD1_UBSAN 0xfffc |
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| 29 | #define BUG_EA 0xffea |
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| 30 | #define BUG_LOCK 0xfff0 |
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| 31 | |
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| 32 | #ifdef CONFIG_GENERIC_BUG |
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| 33 | |
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| 34 | #ifdef CONFIG_X86_32 |
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| 35 | # define __BUG_REL(val) ".long " __stringify(val) |
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| 36 | #else |
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| 37 | # define __BUG_REL(val) ".long " __stringify(val) " - ." |
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| 38 | #endif |
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| 39 | |
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| 40 | #ifdef CONFIG_DEBUG_BUGVERBOSE |
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| 41 | |
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| 42 | #define _BUG_FLAGS(ins, flags, extra) \ |
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| 43 | do { \ |
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| 44 | asm_inline volatile("1:\t" ins "\n" \ |
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| 45 | ".pushsection __bug_table,\"aw\"\n" \ |
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| 46 | "2:\t" __BUG_REL(1b) "\t# bug_entry::bug_addr\n" \ |
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| 47 | "\t" __BUG_REL(%c0) "\t# bug_entry::file\n" \ |
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| 48 | "\t.word %c1" "\t# bug_entry::line\n" \ |
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| 49 | "\t.word %c2" "\t# bug_entry::flags\n" \ |
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| 50 | "\t.org 2b+%c3\n" \ |
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| 51 | ".popsection\n" \ |
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| 52 | extra \ |
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| 53 | : : "i" (__FILE__), "i" (__LINE__), \ |
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| 54 | "i" (flags), \ |
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| 55 | "i" (sizeof(struct bug_entry))); \ |
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| 56 | } while (0) |
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| 57 | |
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| 58 | #else /* !CONFIG_DEBUG_BUGVERBOSE */ |
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| 59 | |
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| 60 | #define _BUG_FLAGS(ins, flags, extra) \ |
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| 61 | do { \ |
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| 62 | asm_inline volatile("1:\t" ins "\n" \ |
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| 63 | ".pushsection __bug_table,\"aw\"\n" \ |
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| 64 | "2:\t" __BUG_REL(1b) "\t# bug_entry::bug_addr\n" \ |
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| 65 | "\t.word %c0" "\t# bug_entry::flags\n" \ |
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| 66 | "\t.org 2b+%c1\n" \ |
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| 67 | ".popsection\n" \ |
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| 68 | extra \ |
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| 69 | : : "i" (flags), \ |
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| 70 | "i" (sizeof(struct bug_entry))); \ |
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| 71 | } while (0) |
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| 72 | |
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| 73 | #endif /* CONFIG_DEBUG_BUGVERBOSE */ |
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| 74 | |
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| 75 | #else |
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| 76 | |
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| 77 | #define _BUG_FLAGS(ins, flags, extra) asm volatile(ins) |
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| 78 | |
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| 79 | #endif /* CONFIG_GENERIC_BUG */ |
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| 80 | |
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| 81 | #define HAVE_ARCH_BUG |
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| 82 | #define BUG() \ |
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| 83 | do { \ |
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| 84 | instrumentation_begin(); \ |
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| 85 | _BUG_FLAGS(ASM_UD2, 0, ""); \ |
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| 86 | __builtin_unreachable(); \ |
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| 87 | } while (0) |
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| 88 | |
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| 89 | /* |
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| 90 | * This instrumentation_begin() is strictly speaking incorrect; but it |
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| 91 | * suppresses the complaints from WARN()s in noinstr code. If such a WARN() |
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| 92 | * were to trigger, we'd rather wreck the machine in an attempt to get the |
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| 93 | * message out than not know about it. |
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| 94 | */ |
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| 95 | #define __WARN_FLAGS(flags) \ |
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| 96 | do { \ |
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| 97 | __auto_type __flags = BUGFLAG_WARNING|(flags); \ |
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| 98 | instrumentation_begin(); \ |
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| 99 | _BUG_FLAGS(ASM_UD2, __flags, ANNOTATE_REACHABLE(1b)); \ |
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| 100 | instrumentation_end(); \ |
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| 101 | } while (0) |
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| 102 | |
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| 103 | #include <asm-generic/bug.h> |
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| 104 | |
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| 105 | #endif /* _ASM_X86_BUG_H */ |
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| 106 | |
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