1/* 2 * Copyright (C) 2012 ARM Ltd. 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License version 2 as 6 * published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope that it will be useful, 9 * but WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11 * GNU General Public License for more details. 12 * 13 * You should have received a copy of the GNU General Public License 14 * along with this program. If not, see <http://www.gnu.org/licenses/>. 15 */ 16 17#include <linux/linkage.h> 18 19#include <asm/alternative.h> 20#include <asm/assembler.h> 21#include <asm/cache.h> 22#include <asm/cpufeature.h> 23#include <asm/sysreg.h> 24 25/* 26 * Copy from user space to a kernel buffer (alignment handled by the hardware) 27 * 28 * Parameters: 29 * x0 - to 30 * x1 - from 31 * x2 - n 32 * Returns: 33 * x0 - bytes not copied 34 */ 35 36 .macro ldrb1 ptr, regB, val 37 uao_user_alternative 9998f, ldrb, ldtrb, \ptr, \regB, \val 38 .endm 39 40 .macro strb1 ptr, regB, val 41 strb \ptr, [\regB], \val 42 .endm 43 44 .macro ldrh1 ptr, regB, val 45 uao_user_alternative 9998f, ldrh, ldtrh, \ptr, \regB, \val 46 .endm 47 48 .macro strh1 ptr, regB, val 49 strh \ptr, [\regB], \val 50 .endm 51 52 .macro ldr1 ptr, regB, val 53 uao_user_alternative 9998f, ldr, ldtr, \ptr, \regB, \val 54 .endm 55 56 .macro str1 ptr, regB, val 57 str \ptr, [\regB], \val 58 .endm 59 60 .macro ldp1 ptr, regB, regC, val 61 uao_ldp 9998f, \ptr, \regB, \regC, \val 62 .endm 63 64 .macro stp1 ptr, regB, regC, val 65 stp \ptr, \regB, [\regC], \val 66 .endm 67 68end .req x5 69ENTRY(__copy_from_user) 70ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(0)), ARM64_HAS_PAN, \ 71 CONFIG_ARM64_PAN) 72 add end, x0, x2 73#include "copy_template.S" 74ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(1)), ARM64_HAS_PAN, \ 75 CONFIG_ARM64_PAN) 76 mov x0, #0 // Nothing to copy 77 ret 78ENDPROC(__copy_from_user) 79 80 .section .fixup,"ax" 81 .align 2 829998: 83 sub x0, end, dst 849999: 85 strb wzr, [dst], #1 // zero remaining buffer space 86 cmp dst, end 87 b.lo 9999b 88 ret 89 .previous 90