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https://github.com/SerenityOS/serenity
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ff1e5aa935
Serenity has explicit_bzero() in LibC with the same implementation, however we need to be able to use this from Lagom on all platforms that we support building serenity on. I've implemented it in AK for this reason.
56 lines
1.1 KiB
C++
56 lines
1.1 KiB
C++
/*
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* Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
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*
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* SPDX-License-Identifier: BSD-2-Clause
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*/
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#pragma once
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#include <AK/Types.h>
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#if defined(KERNEL)
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# include <Kernel/StdLib.h>
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#else
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# include <stdlib.h>
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# include <string.h>
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#endif
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ALWAYS_INLINE void fast_u32_copy(u32* dest, const u32* src, size_t count)
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{
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#if ARCH(I386)
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asm volatile(
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"rep movsl\n"
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: "+S"(src), "+D"(dest), "+c"(count)::"memory");
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#else
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__builtin_memcpy(dest, src, count * 4);
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#endif
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}
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ALWAYS_INLINE void fast_u32_fill(u32* dest, u32 value, size_t count)
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{
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#if ARCH(I386)
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asm volatile(
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"rep stosl\n"
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: "=D"(dest), "=c"(count)
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: "D"(dest), "c"(count), "a"(value)
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: "memory");
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#else
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for (auto* p = dest; p < (dest + count); ++p) {
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*p = value;
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}
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#endif
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}
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namespace AK {
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inline void secure_zero(void* ptr, size_t size)
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{
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__builtin_memset(ptr, 0, size);
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// The memory barrier is here to avoid the compiler optimizing
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// away the memset when we rely on it for wiping secrets.
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asm volatile("" ::
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: "memory");
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}
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}
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using AK::secure_zero;
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