asm-extable.h

 1/* SPDX-License-Identifier: GPL-2.0-only */
 2#ifndef __ASM_ASM_EXTABLE_H
 3#define __ASM_ASM_EXTABLE_H
 4
 5#define EX_TYPE_NONE			0
 6#define EX_TYPE_FIXUP			1
 7#define EX_TYPE_UACCESS_ERR_ZERO	2
 8#define EX_TYPE_BPF			3
 9
10#ifdef __ASSEMBLER__
11
12#define __ASM_EXTABLE_RAW(insn, fixup, type, data)	\
13	.pushsection	__ex_table, "a";		\
14	.balign		4;				\
15	.long		((insn) - .);			\
16	.long		((fixup) - .);			\
17	.short		(type);				\
18	.short		(data);				\
19	.popsection;
20
21	.macro		_asm_extable, insn, fixup
22	__ASM_EXTABLE_RAW(\insn, \fixup, EX_TYPE_FIXUP, 0)
23	.endm
24
25#else /* __ASSEMBLER__ */
26
27#include <linux/bits.h>
28#include <linux/stringify.h>
29#include <asm/gpr-num.h>
30
31#define __ASM_EXTABLE_RAW(insn, fixup, type, data)	\
32	".pushsection	__ex_table, \"a\"\n"		\
33	".balign	4\n"				\
34	".long		((" insn ") - .)\n"		\
35	".long		((" fixup ") - .)\n"		\
36	".short		(" type ")\n"			\
37	".short		(" data ")\n"			\
38	".popsection\n"
39
40#define _ASM_EXTABLE(insn, fixup)	\
41	__ASM_EXTABLE_RAW(#insn, #fixup, __stringify(EX_TYPE_FIXUP), "0")
42
43#define EX_DATA_REG_ERR_SHIFT	0
44#define EX_DATA_REG_ERR		GENMASK(4, 0)
45#define EX_DATA_REG_ZERO_SHIFT	5
46#define EX_DATA_REG_ZERO	GENMASK(9, 5)
47
48#define EX_DATA_REG(reg, gpr)						\
49	"((.L__gpr_num_" #gpr ") << " __stringify(EX_DATA_REG_##reg##_SHIFT) ")"
50
51#define _ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, err, zero)		\
52	__DEFINE_ASM_GPR_NUMS						\
53	__ASM_EXTABLE_RAW(#insn, #fixup, 				\
54			  __stringify(EX_TYPE_UACCESS_ERR_ZERO),	\
55			  "("						\
56			    EX_DATA_REG(ERR, err) " | "			\
57			    EX_DATA_REG(ZERO, zero)			\
58			  ")")
59
60#define _ASM_EXTABLE_UACCESS_ERR(insn, fixup, err)			\
61	_ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, err, zero)
62
63#endif /* __ASSEMBLER__ */
64
65#endif /* __ASM_ASM_EXTABLE_H */