xref: /openbmc/linux/arch/arm/lib/copy_from_user.S (revision 9a29f5fc)
1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 *  linux/arch/arm/lib/copy_from_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_from_user(void *to, const void *from, size_t n)
18 *
19 * Purpose:
20 *
21 *	copy a block to kernel memory from user memory
22 *
23 * Params:
24 *
25 *	to = kernel memory
26 *	from = user memory
27 *	n = number of bytes to copy
28 *
29 * Return value:
30 *
31 *	Number of bytes NOT copied.
32 */
33
34#ifdef CONFIG_CPU_USE_DOMAINS
35
36#ifndef CONFIG_THUMB2_KERNEL
37#define LDR1W_SHIFT	0
38#else
39#define LDR1W_SHIFT	1
40#endif
41
42	.macro ldr1w ptr reg abort
43	ldrusr	\reg, \ptr, 4, abort=\abort
44	.endm
45
46	.macro ldr4w ptr reg1 reg2 reg3 reg4 abort
47	ldr1w \ptr, \reg1, \abort
48	ldr1w \ptr, \reg2, \abort
49	ldr1w \ptr, \reg3, \abort
50	ldr1w \ptr, \reg4, \abort
51	.endm
52
53	.macro ldr8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort
54	ldr4w \ptr, \reg1, \reg2, \reg3, \reg4, \abort
55	ldr4w \ptr, \reg5, \reg6, \reg7, \reg8, \abort
56	.endm
57
58#else
59
60#define LDR1W_SHIFT	0
61
62	.macro ldr1w ptr reg abort
63	USERL(\abort, W(ldr) \reg, [\ptr], #4)
64	.endm
65
66	.macro ldr4w ptr reg1 reg2 reg3 reg4 abort
67	USERL(\abort, ldmia \ptr!, {\reg1, \reg2, \reg3, \reg4})
68	.endm
69
70	.macro ldr8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort
71	USERL(\abort, ldmia \ptr!, {\reg1, \reg2, \reg3, \reg4, \reg5, \reg6, \reg7, \reg8})
72	.endm
73
74#endif /* CONFIG_CPU_USE_DOMAINS */
75
76	.macro ldr1b ptr reg cond=al abort
77	ldrusr	\reg, \ptr, 1, \cond, abort=\abort
78	.endm
79
80#define STR1W_SHIFT	0
81
82	.macro str1w ptr reg abort
83	W(str) \reg, [\ptr], #4
84	.endm
85
86	.macro str8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort
87	stmia \ptr!, {\reg1, \reg2, \reg3, \reg4, \reg5, \reg6, \reg7, \reg8}
88	.endm
89
90	.macro str1b ptr reg cond=al abort
91	strb\cond \reg, [\ptr], #1
92	.endm
93
94	.macro enter regs:vararg
95	mov	r3, #0
96UNWIND( .save	{r0, r2, r3, \regs}		)
97	stmdb	sp!, {r0, r2, r3, \regs}
98	.endm
99
100	.macro exit regs:vararg
101	add	sp, sp, #8
102	ldmfd	sp!, {r0, \regs}
103	.endm
104
105	.text
106
107ENTRY(arm_copy_from_user)
108#ifdef CONFIG_CPU_SPECTRE
109	ldr	r3, =TASK_SIZE
110	uaccess_mask_range_ptr r1, r2, r3, ip
111#endif
112
113#include "copy_template.S"
114
115ENDPROC(arm_copy_from_user)
116
117	.pushsection .text.fixup,"ax"
118	.align 0
119	copy_abort_preamble
120	ldmfd	sp!, {r1, r2, r3}
121	sub	r0, r0, r1
122	rsb	r0, r0, r2
123	copy_abort_end
124	.popsection
125
126