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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
commit | 76cb841cb886eef6b3bee341a2266c76578724ad (patch) | |
tree | f5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /arch/arm64/lib/copy_from_user.S | |
parent | Initial commit. (diff) | |
download | linux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip |
Adding upstream version 4.19.249.upstream/4.19.249upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | arch/arm64/lib/copy_from_user.S | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/arch/arm64/lib/copy_from_user.S b/arch/arm64/lib/copy_from_user.S new file mode 100644 index 000000000..7cd6eeaa2 --- /dev/null +++ b/arch/arm64/lib/copy_from_user.S @@ -0,0 +1,87 @@ +/* + * Copyright (C) 2012 ARM Ltd. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <linux/linkage.h> + +#include <asm/cache.h> +#include <asm/asm-uaccess.h> + +/* + * Copy from user space to a kernel buffer (alignment handled by the hardware) + * + * Parameters: + * x0 - to + * x1 - from + * x2 - n + * Returns: + * x0 - bytes not copied + */ + + .macro ldrb1 ptr, regB, val + uao_user_alternative 9998f, ldrb, ldtrb, \ptr, \regB, \val + .endm + + .macro strb1 ptr, regB, val + strb \ptr, [\regB], \val + .endm + + .macro ldrh1 ptr, regB, val + uao_user_alternative 9997f, ldrh, ldtrh, \ptr, \regB, \val + .endm + + .macro strh1 ptr, regB, val + strh \ptr, [\regB], \val + .endm + + .macro ldr1 ptr, regB, val + uao_user_alternative 9997f, ldr, ldtr, \ptr, \regB, \val + .endm + + .macro str1 ptr, regB, val + str \ptr, [\regB], \val + .endm + + .macro ldp1 ptr, regB, regC, val + uao_ldp 9997f, \ptr, \regB, \regC, \val + .endm + + .macro stp1 ptr, regB, regC, val + stp \ptr, \regB, [\regC], \val + .endm + +end .req x5 +srcin .req x15 +ENTRY(__arch_copy_from_user) + uaccess_enable_not_uao x3, x4, x5 + add end, x0, x2 + mov srcin, x1 +#include "copy_template.S" + uaccess_disable_not_uao x3, x4 + mov x0, #0 // Nothing to copy + ret +ENDPROC(__arch_copy_from_user) + + .section .fixup,"ax" + .align 2 +9997: cmp dst, dstin + b.ne 9998f + // Before being absolutely sure we couldn't copy anything, try harder +USER(9998f, ldtrb tmp1w, [srcin]) + strb tmp1w, [dst], #1 +9998: sub x0, end, dst // bytes not copied + uaccess_disable_not_uao x3, x4 + ret + .previous |