6f1fd68817
mte_supported() lets code efficiently detect the presence of MTE, and ScopedDisableMTE lets code disable MTE RAII-style in a particular region of code. Bug: 135772972 Change-Id: I628a054b50d79f67f39f35d44232b7a2ae166afb
61 lines
2 KiB
C
61 lines
2 KiB
C
/*
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* Copyright (C) 2020 The Android Open Source Project
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* * Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
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* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#pragma once
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#include <sys/auxv.h>
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#include <bionic/mte_kernel.h>
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#ifdef __aarch64__
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inline bool mte_supported() {
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#ifdef ANDROID_EXPERIMENTAL_MTE
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static bool supported = getauxval(AT_HWCAP2) & HWCAP2_MTE;
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#else
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static bool supported = false;
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#endif
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return supported;
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}
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#endif
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struct ScopedDisableMTE {
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ScopedDisableMTE() {
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#ifdef __aarch64__
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if (mte_supported()) {
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__asm__ __volatile__(".arch_extension mte; msr tco, #1");
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}
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#endif
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}
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~ScopedDisableMTE() {
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#ifdef __aarch64__
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if (mte_supported()) {
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__asm__ __volatile__(".arch_extension mte; msr tco, #0");
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}
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#endif
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}
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};
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