xref: /linux/arch/arm/lib/copy_to_user.S (revision 666ed8bfd1de3b091cf32ca03b651757dd86cfff)
1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 *  linux/arch/arm/lib/copy_to_user.S
4 *
5 *  Author:	Nicolas Pitre
6 *  Created:	Sep 29, 2005
7 *  Copyright:	MontaVista Software, Inc.
8 */
9
10#include <linux/linkage.h>
11#include <asm/assembler.h>
12#include <asm/unwind.h>
13
14/*
15 * Prototype:
16 *
17 *	size_t arm_copy_to_user(void *to, const void *from, size_t n)
18 *
19 * Purpose:
20 *
21 *	copy a block to user memory from kernel memory
22 *
23 * Params:
24 *
25 *	to = user memory
26 *	from = kernel memory
27 *	n = number of bytes to copy
28 *
29 * Return value:
30 *
31 *	Number of bytes NOT copied.
32 */
33
34#define LDR1W_SHIFT	0
35
36	.macro ldr1w ptr reg abort
37	W(ldr) \reg, [\ptr], #4
38	.endm
39
40	.macro ldr4w ptr reg1 reg2 reg3 reg4 abort
41	ldmia \ptr!, {\reg1, \reg2, \reg3, \reg4}
42	.endm
43
44	.macro ldr8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort
45	ldmia \ptr!, {\reg1, \reg2, \reg3, \reg4, \reg5, \reg6, \reg7, \reg8}
46	.endm
47
48	.macro ldr1b ptr reg cond=al abort
49	ldrb\cond \reg, [\ptr], #1
50	.endm
51
52#ifdef CONFIG_CPU_USE_DOMAINS
53
54#ifndef CONFIG_THUMB2_KERNEL
55#define STR1W_SHIFT	0
56#else
57#define STR1W_SHIFT	1
58#endif
59
60	.macro str1w ptr reg abort
61	strusr	\reg, \ptr, 4, abort=\abort
62	.endm
63
64	.macro str8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort
65	str1w \ptr, \reg1, \abort
66	str1w \ptr, \reg2, \abort
67	str1w \ptr, \reg3, \abort
68	str1w \ptr, \reg4, \abort
69	str1w \ptr, \reg5, \abort
70	str1w \ptr, \reg6, \abort
71	str1w \ptr, \reg7, \abort
72	str1w \ptr, \reg8, \abort
73	.endm
74
75#else
76
77#define STR1W_SHIFT	0
78
79	.macro str1w ptr reg abort
80	USERL(\abort, W(str) \reg, [\ptr], #4)
81	.endm
82
83	.macro str8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort
84	USERL(\abort, stmia \ptr!, {\reg1, \reg2, \reg3, \reg4, \reg5, \reg6, \reg7, \reg8})
85	.endm
86
87#endif /* CONFIG_CPU_USE_DOMAINS */
88
89	.macro str1b ptr reg cond=al abort
90	strusr	\reg, \ptr, 1, \cond, abort=\abort
91	.endm
92
93	.macro enter reg1 reg2
94	mov	r3, #0
95	stmdb	sp!, {r0, r2, r3, \reg1, \reg2}
96	.endm
97
98	.macro usave reg1 reg2
99	UNWIND(	.save {r0, r2, r3, \reg1, \reg2}	)
100	.endm
101
102	.macro exit reg1 reg2
103	add	sp, sp, #8
104	ldmfd	sp!, {r0, \reg1, \reg2}
105	.endm
106
107	.text
108
109ENTRY(__copy_to_user_std)
110WEAK(arm_copy_to_user)
111#ifdef CONFIG_CPU_SPECTRE
112	get_thread_info r3
113	ldr	r3, [r3, #TI_ADDR_LIMIT]
114	uaccess_mask_range_ptr r0, r2, r3, ip
115#endif
116
117#include "copy_template.S"
118
119ENDPROC(arm_copy_to_user)
120ENDPROC(__copy_to_user_std)
121
122	.pushsection .text.fixup,"ax"
123	.align 0
124	copy_abort_preamble
125	ldmfd	sp!, {r1, r2, r3}
126	sub	r0, r0, r1
127	rsb	r0, r0, r2
128	copy_abort_end
129	.popsection
130