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