1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * Copyright (C) 2012 ARM Ltd. 4 */ 5 6 #include <linux/linkage.h> 7 8 #include <asm/asm-uaccess.h> 9 #include <asm/assembler.h> 10 #include <asm/cache.h> 11 12 /* 13 * Copy to user space from a kernel buffer (alignment handled by the hardware) 14 * 15 * Parameters: 16 * x0 - to 17 * x1 - from 18 * x2 - n 19 * Returns: 20 * x0 - bytes not copied 21 */ 22 .macro ldrb1 reg, ptr, val 23 ldrb \reg, [\ptr], \val 24 .endm 25 26 .macro strb1 reg, ptr, val 27 uao_user_alternative 9998f, strb, sttrb, \reg, \ptr, \val 28 .endm 29 30 .macro ldrh1 reg, ptr, val 31 ldrh \reg, [\ptr], \val 32 .endm 33 34 .macro strh1 reg, ptr, val 35 uao_user_alternative 9997f, strh, sttrh, \reg, \ptr, \val 36 .endm 37 38 .macro ldr1 reg, ptr, val 39 ldr \reg, [\ptr], \val 40 .endm 41 42 .macro str1 reg, ptr, val 43 uao_user_alternative 9997f, str, sttr, \reg, \ptr, \val 44 .endm 45 46 .macro ldp1 reg1, reg2, ptr, val 47 ldp \reg1, \reg2, [\ptr], \val 48 .endm 49 50 .macro stp1 reg1, reg2, ptr, val 51 uao_stp 9997f, \reg1, \reg2, \ptr, \val 52 .endm 53 54 end .req x5 55 srcin .req x15 56 SYM_FUNC_START(__arch_copy_to_user) 57 add end, x0, x2 58 mov srcin, x1 59 #include "copy_template.S" 60 mov x0, #0 61 ret 62 SYM_FUNC_END(__arch_copy_to_user) 63 EXPORT_SYMBOL(__arch_copy_to_user) 64 65 .section .fixup,"ax" 66 .align 2 67 9997: cmp dst, dstin 68 b.ne 9998f 69 // Before being absolutely sure we couldn't copy anything, try harder 70 ldrb tmp1w, [srcin] 71 USER(9998f, sttrb tmp1w, [dst]) 72 add dst, dst, #1 73 9998: sub x0, end, dst // bytes not copied 74 ret 75 .previous 76