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 " val
36#else
37# define __BUG_REL(val) ".long " val " - ."
38#endif
39
40#ifdef CONFIG_DEBUG_BUGVERBOSE
41#define __BUG_ENTRY(file, line, flags) \
42 "2:\t" __BUG_REL("1b") "\t# bug_entry::bug_addr\n" \
43 "\t" __BUG_REL(file) "\t# bug_entry::file\n" \
44 "\t.word " line "\t# bug_entry::line\n" \
45 "\t.word " flags "\t# bug_entry::flags\n"
46#else
47#define __BUG_ENTRY(file, line, flags) \
48 "2:\t" __BUG_REL("1b") "\t# bug_entry::bug_addr\n" \
49 "\t.word " flags "\t# bug_entry::flags\n"
50#endif
51
52#define _BUG_FLAGS_ASM(ins, file, line, flags, size, extra) \
53 "1:\t" ins "\n" \
54 ".pushsection __bug_table,\"aw\"\n" \
55 __BUG_ENTRY(file, line, flags) \
56 "\t.org 2b + " size "\n" \
57 ".popsection\n" \
58 extra
59
60#define _BUG_FLAGS(ins, flags, extra) \
61do { \
62 asm_inline volatile(_BUG_FLAGS_ASM(ins, "%c0", \
63 "%c1", "%c2", "%c3", extra) \
64 : : "i" (__FILE__), "i" (__LINE__), \
65 "i" (flags), \
66 "i" (sizeof(struct bug_entry))); \
67} while (0)
68
69#define ARCH_WARN_ASM(file, line, flags, size) \
70 _BUG_FLAGS_ASM(ASM_UD2, file, line, flags, size, "")
71
72#else
73
74#define _BUG_FLAGS(ins, flags, extra) asm volatile(ins)
75
76#endif /* CONFIG_GENERIC_BUG */
77
78#define HAVE_ARCH_BUG
79#define BUG() \
80do { \
81 instrumentation_begin(); \
82 _BUG_FLAGS(ASM_UD2, 0, ""); \
83 __builtin_unreachable(); \
84} while (0)
85
86/*
87 * This instrumentation_begin() is strictly speaking incorrect; but it
88 * suppresses the complaints from WARN()s in noinstr code. If such a WARN()
89 * were to trigger, we'd rather wreck the machine in an attempt to get the
90 * message out than not know about it.
91 */
92
93#define ARCH_WARN_REACHABLE ANNOTATE_REACHABLE(1b)
94
95#define __WARN_FLAGS(flags) \
96do { \
97 __auto_type __flags = BUGFLAG_WARNING|(flags); \
98 instrumentation_begin(); \
99 _BUG_FLAGS(ASM_UD2, __flags, ARCH_WARN_REACHABLE); \
100 instrumentation_end(); \
101} while (0)
102
103#include <asm-generic/bug.h>
104
105#endif /* _ASM_X86_BUG_H */