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author | Arnd Bergmann <arnd@arndb.de> | 2012-10-04 22:57:00 +0200 |
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committer | Arnd Bergmann <arnd@arndb.de> | 2012-10-04 22:57:51 +0200 |
commit | c37d6154c0b9163c27e53cc1d0be3867b4abd760 (patch) | |
tree | 7a24522c56d1cb284dff1d3c225bbdaba0901bb5 /arch/arm64/lib/clear_user.S | |
parent | asm-generic: Add default clkdev.h (diff) | |
parent | UAPI: (Scripted) Disintegrate include/asm-generic (diff) | |
download | linux-c37d6154c0b9163c27e53cc1d0be3867b4abd760.tar.xz linux-c37d6154c0b9163c27e53cc1d0be3867b4abd760.zip |
Merge branch 'disintegrate-asm-generic' of git://git.infradead.org/users/dhowells/linux-headers into asm-generic
Patches from David Howells <dhowells@redhat.com>:
This is to complete part of the UAPI disintegration for which the
preparatory patches were pulled recently.
Note that there are some fixup patches which are at the base of the
branch aimed at you, plus all arches get the asm-generic branch merged in too.
* 'disintegrate-asm-generic' of git://git.infradead.org/users/dhowells/linux-headers:
UAPI: (Scripted) Disintegrate include/asm-generic
UAPI: Fix conditional header installation handling (notably kvm_para.h on m68k)
c6x: remove c6x signal.h
UAPI: Split compound conditionals containing __KERNEL__ in Arm64
UAPI: Fix the guards on various asm/unistd.h files
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'arch/arm64/lib/clear_user.S')
-rw-r--r-- | arch/arm64/lib/clear_user.S | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/arch/arm64/lib/clear_user.S b/arch/arm64/lib/clear_user.S new file mode 100644 index 000000000000..6e0ed93d51fe --- /dev/null +++ b/arch/arm64/lib/clear_user.S @@ -0,0 +1,58 @@ +/* + * Based on arch/arm/lib/clear_user.S + * + * 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/assembler.h> + + .text + +/* Prototype: int __clear_user(void *addr, size_t sz) + * Purpose : clear some user memory + * Params : addr - user memory address to clear + * : sz - number of bytes to clear + * Returns : number of bytes NOT cleared + * + * Alignment fixed up by hardware. + */ +ENTRY(__clear_user) + mov x2, x1 // save the size for fixup return + subs x1, x1, #8 + b.mi 2f +1: +USER(9f, str xzr, [x0], #8 ) + subs x1, x1, #8 + b.pl 1b +2: adds x1, x1, #4 + b.mi 3f +USER(9f, str wzr, [x0], #4 ) + sub x1, x1, #4 +3: adds x1, x1, #2 + b.mi 4f +USER(9f, strh wzr, [x0], #2 ) + sub x1, x1, #2 +4: adds x1, x1, #1 + b.mi 5f + strb wzr, [x0] +5: mov x0, #0 + ret +ENDPROC(__clear_user) + + .section .fixup,"ax" + .align 2 +9: mov x0, x2 // return the original size + ret + .previous |