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
96 UNWIND( .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
107 ENTRY(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
115 ENDPROC(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
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