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