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author | Matt A. Tobin <mattatobin@localhost.localdomain> | 2018-02-02 04:16:08 -0500 |
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committer | Matt A. Tobin <mattatobin@localhost.localdomain> | 2018-02-02 04:16:08 -0500 |
commit | 5f8de423f190bbb79a62f804151bc24824fa32d8 (patch) | |
tree | 10027f336435511475e392454359edea8e25895d /security/sandbox/chromium/base/cpu.cc | |
parent | 49ee0794b5d912db1f95dce6eb52d781dc210db5 (diff) | |
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Add m-esr52 at 52.6.0
Diffstat (limited to 'security/sandbox/chromium/base/cpu.cc')
-rw-r--r-- | security/sandbox/chromium/base/cpu.cc | 296 |
1 files changed, 296 insertions, 0 deletions
diff --git a/security/sandbox/chromium/base/cpu.cc b/security/sandbox/chromium/base/cpu.cc new file mode 100644 index 000000000..713544566 --- /dev/null +++ b/security/sandbox/chromium/base/cpu.cc @@ -0,0 +1,296 @@ +// Copyright (c) 2012 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +#include "base/cpu.h" + +#include <limits.h> +#include <stddef.h> +#include <stdint.h> +#include <stdlib.h> +#include <string.h> + +#include <algorithm> + +#include "base/macros.h" +#include "base/strings/string_piece.h" +#include "build/build_config.h" + +#if defined(ARCH_CPU_ARM_FAMILY) && (defined(OS_ANDROID) || defined(OS_LINUX)) +#include "base/files/file_util.h" +#include "base/lazy_instance.h" +#endif + +#if defined(ARCH_CPU_X86_FAMILY) +#if defined(_MSC_VER) +#include <intrin.h> +#include <immintrin.h> // For _xgetbv() +#endif +#endif + +namespace base { + +CPU::CPU() + : signature_(0), + type_(0), + family_(0), + model_(0), + stepping_(0), + ext_model_(0), + ext_family_(0), + has_mmx_(false), + has_sse_(false), + has_sse2_(false), + has_sse3_(false), + has_ssse3_(false), + has_sse41_(false), + has_sse42_(false), + has_avx_(false), + has_avx2_(false), + has_aesni_(false), + has_non_stop_time_stamp_counter_(false), + has_broken_neon_(false), + cpu_vendor_("unknown") { + Initialize(); +} + +namespace { + +#if defined(ARCH_CPU_X86_FAMILY) +#ifndef _MSC_VER + +#if defined(__pic__) && defined(__i386__) + +void __cpuid(int cpu_info[4], int info_type) { + __asm__ volatile ( + "mov %%ebx, %%edi\n" + "cpuid\n" + "xchg %%edi, %%ebx\n" + : "=a"(cpu_info[0]), "=D"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3]) + : "a"(info_type) + ); +} + +#else + +void __cpuid(int cpu_info[4], int info_type) { + __asm__ volatile ( + "cpuid\n" + : "=a"(cpu_info[0]), "=b"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3]) + : "a"(info_type) + ); +} + +#endif + +// _xgetbv returns the value of an Intel Extended Control Register (XCR). +// Currently only XCR0 is defined by Intel so |xcr| should always be zero. +uint64_t _xgetbv(uint32_t xcr) { + uint32_t eax, edx; + + __asm__ volatile ( + "xgetbv" : "=a"(eax), "=d"(edx) : "c"(xcr)); + return (static_cast<uint64_t>(edx) << 32) | eax; +} + +#endif // !_MSC_VER +#endif // ARCH_CPU_X86_FAMILY + +#if defined(ARCH_CPU_ARM_FAMILY) && (defined(OS_ANDROID) || defined(OS_LINUX)) +class LazyCpuInfoValue { + public: + LazyCpuInfoValue() : has_broken_neon_(false) { + // This function finds the value from /proc/cpuinfo under the key "model + // name" or "Processor". "model name" is used in Linux 3.8 and later (3.7 + // and later for arm64) and is shown once per CPU. "Processor" is used in + // earler versions and is shown only once at the top of /proc/cpuinfo + // regardless of the number CPUs. + const char kModelNamePrefix[] = "model name\t: "; + const char kProcessorPrefix[] = "Processor\t: "; + + // This function also calculates whether we believe that this CPU has a + // broken NEON unit based on these fields from cpuinfo: + unsigned implementer = 0, architecture = 0, variant = 0, part = 0, + revision = 0; + const struct { + const char key[17]; + unsigned int* result; + } kUnsignedValues[] = { + {"CPU implementer", &implementer}, + {"CPU architecture", &architecture}, + {"CPU variant", &variant}, + {"CPU part", &part}, + {"CPU revision", &revision}, + }; + + std::string contents; + ReadFileToString(FilePath("/proc/cpuinfo"), &contents); + DCHECK(!contents.empty()); + if (contents.empty()) { + return; + } + + std::istringstream iss(contents); + std::string line; + while (std::getline(iss, line)) { + if (brand_.empty() && + (line.compare(0, strlen(kModelNamePrefix), kModelNamePrefix) == 0 || + line.compare(0, strlen(kProcessorPrefix), kProcessorPrefix) == 0)) { + brand_.assign(line.substr(strlen(kModelNamePrefix))); + } + + for (size_t i = 0; i < arraysize(kUnsignedValues); i++) { + const char *key = kUnsignedValues[i].key; + const size_t len = strlen(key); + + if (line.compare(0, len, key) == 0 && + line.size() >= len + 1 && + (line[len] == '\t' || line[len] == ' ' || line[len] == ':')) { + size_t colon_pos = line.find(':', len); + if (colon_pos == std::string::npos) { + continue; + } + + const StringPiece line_sp(line); + StringPiece value_sp = line_sp.substr(colon_pos + 1); + while (!value_sp.empty() && + (value_sp[0] == ' ' || value_sp[0] == '\t')) { + value_sp = value_sp.substr(1); + } + + // The string may have leading "0x" or not, so we use strtoul to + // handle that. + char* endptr; + std::string value(value_sp.as_string()); + unsigned long int result = strtoul(value.c_str(), &endptr, 0); + if (*endptr == 0 && result <= UINT_MAX) { + *kUnsignedValues[i].result = result; + } + } + } + } + + has_broken_neon_ = + implementer == 0x51 && + architecture == 7 && + variant == 1 && + part == 0x4d && + revision == 0; + } + + const std::string& brand() const { return brand_; } + bool has_broken_neon() const { return has_broken_neon_; } + + private: + std::string brand_; + bool has_broken_neon_; + DISALLOW_COPY_AND_ASSIGN(LazyCpuInfoValue); +}; + +base::LazyInstance<LazyCpuInfoValue>::Leaky g_lazy_cpuinfo = + LAZY_INSTANCE_INITIALIZER; + +#endif // defined(ARCH_CPU_ARM_FAMILY) && (defined(OS_ANDROID) || + // defined(OS_LINUX)) + +} // anonymous namespace + +void CPU::Initialize() { +#if defined(ARCH_CPU_X86_FAMILY) + int cpu_info[4] = {-1}; + char cpu_string[48]; + + // __cpuid with an InfoType argument of 0 returns the number of + // valid Ids in CPUInfo[0] and the CPU identification string in + // the other three array elements. The CPU identification string is + // not in linear order. The code below arranges the information + // in a human readable form. The human readable order is CPUInfo[1] | + // CPUInfo[3] | CPUInfo[2]. CPUInfo[2] and CPUInfo[3] are swapped + // before using memcpy to copy these three array elements to cpu_string. + __cpuid(cpu_info, 0); + int num_ids = cpu_info[0]; + std::swap(cpu_info[2], cpu_info[3]); + memcpy(cpu_string, &cpu_info[1], 3 * sizeof(cpu_info[1])); + cpu_vendor_.assign(cpu_string, 3 * sizeof(cpu_info[1])); + + // Interpret CPU feature information. + if (num_ids > 0) { + int cpu_info7[4] = {0}; + __cpuid(cpu_info, 1); + if (num_ids >= 7) { + __cpuid(cpu_info7, 7); + } + signature_ = cpu_info[0]; + stepping_ = cpu_info[0] & 0xf; + model_ = ((cpu_info[0] >> 4) & 0xf) + ((cpu_info[0] >> 12) & 0xf0); + family_ = (cpu_info[0] >> 8) & 0xf; + type_ = (cpu_info[0] >> 12) & 0x3; + ext_model_ = (cpu_info[0] >> 16) & 0xf; + ext_family_ = (cpu_info[0] >> 20) & 0xff; + has_mmx_ = (cpu_info[3] & 0x00800000) != 0; + has_sse_ = (cpu_info[3] & 0x02000000) != 0; + has_sse2_ = (cpu_info[3] & 0x04000000) != 0; + has_sse3_ = (cpu_info[2] & 0x00000001) != 0; + has_ssse3_ = (cpu_info[2] & 0x00000200) != 0; + has_sse41_ = (cpu_info[2] & 0x00080000) != 0; + has_sse42_ = (cpu_info[2] & 0x00100000) != 0; + // AVX instructions will generate an illegal instruction exception unless + // a) they are supported by the CPU, + // b) XSAVE is supported by the CPU and + // c) XSAVE is enabled by the kernel. + // See http://software.intel.com/en-us/blogs/2011/04/14/is-avx-enabled + // + // In addition, we have observed some crashes with the xgetbv instruction + // even after following Intel's example code. (See crbug.com/375968.) + // Because of that, we also test the XSAVE bit because its description in + // the CPUID documentation suggests that it signals xgetbv support. + has_avx_ = + (cpu_info[2] & 0x10000000) != 0 && + (cpu_info[2] & 0x04000000) != 0 /* XSAVE */ && + (cpu_info[2] & 0x08000000) != 0 /* OSXSAVE */ && + (_xgetbv(0) & 6) == 6 /* XSAVE enabled by kernel */; + has_aesni_ = (cpu_info[2] & 0x02000000) != 0; + has_avx2_ = has_avx_ && (cpu_info7[1] & 0x00000020) != 0; + } + + // Get the brand string of the cpu. + __cpuid(cpu_info, 0x80000000); + const int parameter_end = 0x80000004; + int max_parameter = cpu_info[0]; + + if (cpu_info[0] >= parameter_end) { + char* cpu_string_ptr = cpu_string; + + for (int parameter = 0x80000002; parameter <= parameter_end && + cpu_string_ptr < &cpu_string[sizeof(cpu_string)]; parameter++) { + __cpuid(cpu_info, parameter); + memcpy(cpu_string_ptr, cpu_info, sizeof(cpu_info)); + cpu_string_ptr += sizeof(cpu_info); + } + cpu_brand_.assign(cpu_string, cpu_string_ptr - cpu_string); + } + + const int parameter_containing_non_stop_time_stamp_counter = 0x80000007; + if (max_parameter >= parameter_containing_non_stop_time_stamp_counter) { + __cpuid(cpu_info, parameter_containing_non_stop_time_stamp_counter); + has_non_stop_time_stamp_counter_ = (cpu_info[3] & (1 << 8)) != 0; + } +#elif defined(ARCH_CPU_ARM_FAMILY) && (defined(OS_ANDROID) || defined(OS_LINUX)) + cpu_brand_.assign(g_lazy_cpuinfo.Get().brand()); + has_broken_neon_ = g_lazy_cpuinfo.Get().has_broken_neon(); +#endif +} + +CPU::IntelMicroArchitecture CPU::GetIntelMicroArchitecture() const { + if (has_avx2()) return AVX2; + if (has_avx()) return AVX; + if (has_sse42()) return SSE42; + if (has_sse41()) return SSE41; + if (has_ssse3()) return SSSE3; + if (has_sse3()) return SSE3; + if (has_sse2()) return SSE2; + if (has_sse()) return SSE; + return PENTIUM; +} + +} // namespace base |