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 regs:vararg
94 mov r3, #0
95UNWIND( .save {r0, r2, r3, \regs} )
96 stmdb sp!, {r0, r2, r3, \regs}
97 .endm
98
99 .macro exit regs:vararg
100 add sp, sp, #8
101 ldmfd sp!, {r0, \regs}
102 .endm
103
104 .text
105
106ENTRY(__copy_to_user_std)
107WEAK(arm_copy_to_user)
108#ifdef CONFIG_CPU_SPECTRE
109 ldr r3, =TASK_SIZE
110 uaccess_mask_range_ptr r0, r2, r3, ip
111#endif
112
113#include "copy_template.S"
114
115ENDPROC(arm_copy_to_user)
116ENDPROC(__copy_to_user_std)
117
118 .pushsection .text.fixup,"ax"
119 .align 0
120 copy_abort_preamble
121 ldmfd sp!, {r1, r2, r3}
122 sub r0, r0, r1
123 rsb r0, r0, r2
124 copy_abort_end
125 .popsection
126

source code of linux/arch/arm/lib/copy_to_user.S