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