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OpenCloudOS-Kernel/arch/arm64/lib/strchr.S

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treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234 Based on 1 normalized pattern(s): 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 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 503 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Enrico Weigelt <info@metux.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190602204653.811534538@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-03 13:44:50 +08:00
/* SPDX-License-Identifier: GPL-2.0-only */
arm64: klib: Optimised string functions This patch introduces AArch64-specific string functions (strchr, strrchr). Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2013-03-22 00:23:43 +08:00
/*
* Based on arch/arm/lib/strchr.S
*
* Copyright (C) 1995-2000 Russell King
* Copyright (C) 2013 ARM Ltd.
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
/*
* Find the first occurrence of a character in a string.
*
* Parameters:
* x0 - str
* x1 - c
* Returns:
* x0 - address of first occurrence of 'c' or 0
*/
arm64: lib: use C string functions with KASAN enabled ARM64 has asm implementation of memchr(), memcmp(), str[r]chr(), str[n]cmp(), str[n]len(). KASAN don't see memory accesses in asm code, thus it can potentially miss many bugs. Ifdef out __HAVE_ARCH_* defines of these functions when KASAN is enabled, so the generic implementations from lib/string.c will be used. We can't just remove the asm functions because efistub uses them. And we can't have two non-weak functions either, so declare the asm functions as weak. Link: http://lkml.kernel.org/r/20180920135631.23833-2-aryabinin@virtuozzo.com Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Reported-by: Kyeongdon Kim <kyeongdon.kim@lge.com> Cc: Alexander Potapenko <glider@google.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-10-27 06:02:30 +08:00
WEAK(strchr)
arm64: klib: Optimised string functions This patch introduces AArch64-specific string functions (strchr, strrchr). Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2013-03-22 00:23:43 +08:00
and w1, w1, #0xff
1: ldrb w2, [x0], #1
cmp w2, w1
ccmp w2, wzr, #4, ne
b.ne 1b
sub x0, x0, #1
cmp w2, w1
csel x0, x0, xzr, eq
ret
ENDPROC(strchr)
arm64: string: use asm EXPORT_SYMBOL() For a while now it's been possible to use EXPORT_SYMBOL() in assembly files, which allows us to place exports immediately after assembly functions, as we do for C functions. As a step towards removing arm64ksyms.c, let's move the string routine exports to the assembly files the functions are defined in. Routines which should only be exported for !KASAN builds are exported using the EXPORT_SYMBOL_NOKASAN() helper. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-12-08 02:08:21 +08:00
EXPORT_SYMBOL_NOKASAN(strchr)