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Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
1/* SPDX-License-Identifier: GPL-2.0-only */
2#ifndef __ASM_ASM_EXTABLE_H
3#define __ASM_ASM_EXTABLE_H
4
5#include <linux/bits.h>
6#include <asm/gpr-num.h>
7
8#define EX_TYPE_NONE 0
9#define EX_TYPE_BPF 1
10#define EX_TYPE_UACCESS_ERR_ZERO 2
11#define EX_TYPE_KACCESS_ERR_ZERO 3
12#define EX_TYPE_LOAD_UNALIGNED_ZEROPAD 4
13
14/* Data fields for EX_TYPE_UACCESS_ERR_ZERO */
15#define EX_DATA_REG_ERR_SHIFT 0
16#define EX_DATA_REG_ERR GENMASK(4, 0)
17#define EX_DATA_REG_ZERO_SHIFT 5
18#define EX_DATA_REG_ZERO GENMASK(9, 5)
19
20/* Data fields for EX_TYPE_LOAD_UNALIGNED_ZEROPAD */
21#define EX_DATA_REG_DATA_SHIFT 0
22#define EX_DATA_REG_DATA GENMASK(4, 0)
23#define EX_DATA_REG_ADDR_SHIFT 5
24#define EX_DATA_REG_ADDR GENMASK(9, 5)
25
26#ifdef __ASSEMBLY__
27
28#define __ASM_EXTABLE_RAW(insn, fixup, type, data) \
29 .pushsection __ex_table, "a"; \
30 .align 2; \
31 .long ((insn) - .); \
32 .long ((fixup) - .); \
33 .short (type); \
34 .short (data); \
35 .popsection;
36
37#define EX_DATA_REG(reg, gpr) \
38 (.L__gpr_num_##gpr << EX_DATA_REG_##reg##_SHIFT)
39
40#define _ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, err, zero) \
41 __ASM_EXTABLE_RAW(insn, fixup, \
42 EX_TYPE_UACCESS_ERR_ZERO, \
43 ( \
44 EX_DATA_REG(ERR, err) | \
45 EX_DATA_REG(ZERO, zero) \
46 ))
47
48#define _ASM_EXTABLE_UACCESS_ERR(insn, fixup, err) \
49 _ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, err, wzr)
50
51#define _ASM_EXTABLE_UACCESS(insn, fixup) \
52 _ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, wzr, wzr)
53
54/*
55 * Create an exception table entry for uaccess `insn`, which will branch to `fixup`
56 * when an unhandled fault is taken.
57 */
58 .macro _asm_extable_uaccess, insn, fixup
59 _ASM_EXTABLE_UACCESS(\insn, \fixup)
60 .endm
61
62/*
63 * Create an exception table entry for `insn` if `fixup` is provided. Otherwise
64 * do nothing.
65 */
66 .macro _cond_uaccess_extable, insn, fixup
67 .ifnc \fixup,
68 _asm_extable_uaccess \insn, \fixup
69 .endif
70 .endm
71
72#else /* __ASSEMBLY__ */
73
74#include <linux/stringify.h>
75
76#define __ASM_EXTABLE_RAW(insn, fixup, type, data) \
77 ".pushsection __ex_table, \"a\"\n" \
78 ".align 2\n" \
79 ".long ((" insn ") - .)\n" \
80 ".long ((" fixup ") - .)\n" \
81 ".short (" type ")\n" \
82 ".short (" data ")\n" \
83 ".popsection\n"
84
85#define EX_DATA_REG(reg, gpr) \
86 "((.L__gpr_num_" #gpr ") << " __stringify(EX_DATA_REG_##reg##_SHIFT) ")"
87
88#define _ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, err, zero) \
89 __DEFINE_ASM_GPR_NUMS \
90 __ASM_EXTABLE_RAW(#insn, #fixup, \
91 __stringify(EX_TYPE_UACCESS_ERR_ZERO), \
92 "(" \
93 EX_DATA_REG(ERR, err) " | " \
94 EX_DATA_REG(ZERO, zero) \
95 ")")
96
97#define _ASM_EXTABLE_KACCESS_ERR_ZERO(insn, fixup, err, zero) \
98 __DEFINE_ASM_GPR_NUMS \
99 __ASM_EXTABLE_RAW(#insn, #fixup, \
100 __stringify(EX_TYPE_KACCESS_ERR_ZERO), \
101 "(" \
102 EX_DATA_REG(ERR, err) " | " \
103 EX_DATA_REG(ZERO, zero) \
104 ")")
105
106#define _ASM_EXTABLE_UACCESS_ERR(insn, fixup, err) \
107 _ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, err, wzr)
108
109#define _ASM_EXTABLE_UACCESS(insn, fixup) \
110 _ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, wzr, wzr)
111
112#define _ASM_EXTABLE_KACCESS_ERR(insn, fixup, err) \
113 _ASM_EXTABLE_KACCESS_ERR_ZERO(insn, fixup, err, wzr)
114
115#define _ASM_EXTABLE_LOAD_UNALIGNED_ZEROPAD(insn, fixup, data, addr) \
116 __DEFINE_ASM_GPR_NUMS \
117 __ASM_EXTABLE_RAW(#insn, #fixup, \
118 __stringify(EX_TYPE_LOAD_UNALIGNED_ZEROPAD), \
119 "(" \
120 EX_DATA_REG(DATA, data) " | " \
121 EX_DATA_REG(ADDR, addr) \
122 ")")
123
124#endif /* __ASSEMBLY__ */
125
126#endif /* __ASM_ASM_EXTABLE_H */