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19a2ca0fb5
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>
44 lines
1.1 KiB
ArmAsm
44 lines
1.1 KiB
ArmAsm
/*
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* Based on arch/arm/lib/strrchr.S
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*
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* Copyright (C) 1995-2000 Russell King
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* Copyright (C) 2013 ARM Ltd.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <linux/linkage.h>
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#include <asm/assembler.h>
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/*
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* Find the last occurrence of a character in a string.
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*
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* Parameters:
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* x0 - str
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* x1 - c
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* Returns:
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* x0 - address of last occurrence of 'c' or 0
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*/
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WEAK(strrchr)
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mov x3, #0
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and w1, w1, #0xff
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1: ldrb w2, [x0], #1
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cbz w2, 2f
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cmp w2, w1
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b.ne 1b
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sub x3, x0, #1
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b 1b
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2: mov x0, x3
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ret
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ENDPIPROC(strrchr)
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