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sed -i '' -E -e 's/Copyright (.+) The Crashpad Authors\. All rights reserved\.$/Copyright \1 The Crashpad Authors/' $(git grep -El 'Copyright (.+) The Crashpad Authors\. All rights reserved\.$') Bug: chromium:1098010 Change-Id: I8d6138469ddbe3d281a5d83f64cf918ec2491611 Reviewed-on: https://chromium-review.googlesource.com/c/crashpad/crashpad/+/3878262 Reviewed-by: Joshua Peraza <jperaza@chromium.org> Commit-Queue: Mark Mentovai <mark@chromium.org>
139 lines
4.0 KiB
C++
139 lines
4.0 KiB
C++
// Copyright 2017 The Crashpad Authors
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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#include "snapshot/x86/cpuid_reader.h"
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#include <stddef.h>
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#include "build/build_config.h"
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#include "snapshot/cpu_context.h"
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#if BUILDFLAG(IS_WIN)
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#include <immintrin.h>
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#include <intrin.h>
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#endif // BUILDFLAG(IS_WIN)
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#if defined(ARCH_CPU_X86_FAMILY)
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namespace crashpad {
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namespace internal {
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CpuidReader::CpuidReader()
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: features_(0),
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extended_features_(0),
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vendor_(),
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max_leaf_(0),
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signature_(0) {
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uint32_t cpuinfo[4];
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Cpuid(cpuinfo, 0);
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max_leaf_ = cpuinfo[0];
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vendor_.append(reinterpret_cast<char*>(&cpuinfo[1]), 4);
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vendor_.append(reinterpret_cast<char*>(&cpuinfo[3]), 4);
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vendor_.append(reinterpret_cast<char*>(&cpuinfo[2]), 4);
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Cpuid(cpuinfo, 1);
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signature_ = cpuinfo[0];
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features_ = (static_cast<uint64_t>(cpuinfo[2]) << 32) |
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static_cast<uint64_t>(cpuinfo[3]);
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Cpuid(cpuinfo, 0x80000001);
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extended_features_ = (static_cast<uint64_t>(cpuinfo[2]) << 32) |
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static_cast<uint64_t>(cpuinfo[3]);
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}
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CpuidReader::~CpuidReader() {}
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uint32_t CpuidReader::Revision() const {
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uint8_t stepping = signature_ & 0xf;
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uint8_t model = (signature_ & 0xf0) >> 4;
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uint8_t family = (signature_ & 0xf00) >> 8;
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uint8_t extended_model = static_cast<uint8_t>((signature_ & 0xf0000) >> 16);
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uint16_t extended_family = (signature_ & 0xff00000) >> 20;
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// For families before 15, extended_family are simply reserved bits.
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if (family < 15)
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extended_family = 0;
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// extended_model is only used for families 6 and 15.
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if (family != 6 && family != 15)
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extended_model = 0;
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uint16_t adjusted_family = family + extended_family;
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uint8_t adjusted_model = model + (extended_model << 4);
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return (adjusted_family << 16) | (adjusted_model << 8) | stepping;
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}
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uint32_t CpuidReader::Leaf7Features() const {
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if (max_leaf_ < 7) {
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return 0;
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}
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uint32_t cpuinfo[4];
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Cpuid(cpuinfo, 7);
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return cpuinfo[1];
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}
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bool CpuidReader::SupportsDAZ() const {
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// The correct way to check for denormals-as-zeros (DAZ) support is to examine
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// mxcsr mask, which can be done with fxsave. See Intel Software Developer’s
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// Manual, Volume 1: Basic Architecture (253665-051), 11.6.3 “Checking for the
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// DAZ Flag in the MXCSR Register”. Note that since this function tests for
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// DAZ support in the CPU, it checks the mxcsr mask. Testing mxcsr would
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// indicate whether DAZ is actually enabled, which is a per-thread context
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// concern.
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// Test for fxsave support.
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if (!(features_ & (UINT64_C(1) << 24))) {
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return false;
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}
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#if defined(ARCH_CPU_X86)
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using Fxsave = CPUContextX86::Fxsave;
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#elif defined(ARCH_CPU_X86_64)
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using Fxsave = CPUContextX86_64::Fxsave;
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#endif
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#if BUILDFLAG(IS_WIN)
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__declspec(align(16)) Fxsave fxsave = {};
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#else
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Fxsave fxsave __attribute__((aligned(16))) = {};
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#endif
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static_assert(sizeof(fxsave) == 512, "fxsave size");
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static_assert(offsetof(decltype(fxsave), mxcsr_mask) == 28,
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"mxcsr_mask offset");
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#if BUILDFLAG(IS_WIN)
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_fxsave(&fxsave);
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#else
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asm("fxsave %0" : "=m"(fxsave));
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#endif
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// Test the DAZ bit.
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return (fxsave.mxcsr_mask & (1 << 6)) != 0;
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}
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void CpuidReader::Cpuid(uint32_t cpuinfo[4], uint32_t leaf) const {
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#if BUILDFLAG(IS_WIN)
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__cpuid(reinterpret_cast<int*>(cpuinfo), leaf);
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#else
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asm("cpuid"
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: "=a"(cpuinfo[0]), "=b"(cpuinfo[1]), "=c"(cpuinfo[2]), "=d"(cpuinfo[3])
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: "a"(leaf), "b"(0), "c"(0), "d"(0));
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#endif // BUILDFLAG(IS_WIN)
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}
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} // namespace internal
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} // namespace crashpad
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#endif // ARCH_CPU_X86_FAMILY
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