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_KACCESS(insn, fixup) \
116 _ASM_EXTABLE_KACCESS_ERR_ZERO(insn, fixup, wzr, wzr)
117
118 #define _ASM_EXTABLE_LOAD_UNALIGNED_ZEROPAD(insn, fixup, data, addr) \
119 __DEFINE_ASM_GPR_NUMS \
120 __ASM_EXTABLE_RAW(#insn, #fixup, \
121 __stringify(EX_TYPE_LOAD_UNALIGNED_ZEROPAD), \
122 "(" \
123 EX_DATA_REG(DATA, data) " | " \
124 EX_DATA_REG(ADDR, addr) \
125 ")")
126
127 #endif /* __ASSEMBLY__ */
128
129 #endif /* __ASM_ASM_EXTABLE_H */
130
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.