The Tor Browser: security/sandbox/chromium/base/cpu.cc@b8a032363ba2 (annotated)

security/sandbox/chromium/base/cpu.cc@b8a032363ba2 (annotated)

security/sandbox/chromium/base/cpu.cc

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 // 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 <string.h>
 #include <algorithm>
 #include "build/build_config.h"
 #if defined(ARCH_CPU_X86_FAMILY)
 #if defined(_MSC_VER)
 #include <intrin.h>
 #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_non_stop_time_stamp_counter_(false),
     cpu_vendor_("unknown") {
   Initialize();
 }
 #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)
   );
 }
 void __cpuidex(int cpu_info[4], int info_type, int info_index) {
   __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), "c"(info_index)
   );
 }
 #else
 void __cpuid(int cpu_info[4], int info_type) {
   __asm__ volatile (
     "cpuid \n\t"
     : "=a"(cpu_info[0]), "=b"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3])
     : "a"(info_type)
   );
 }
 void __cpuidex(int cpu_info[4], int info_type, int info_index) {
   __asm__ volatile (
     "cpuid \n\t"
     : "=a"(cpu_info[0]), "=b"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3])
     : "a"(info_type), "c"(info_index)
   );
 }
 #endif
 #endif  // _MSC_VER
 #endif  // ARCH_CPU_X86_FAMILY
 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) {
     __cpuid(cpu_info, 1);
     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;
     has_avx_ = (cpu_info[2] & 0x10000000) != 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;
   }
 #endif
 }
 CPU::IntelMicroArchitecture CPU::GetIntelMicroArchitecture() const {
   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

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security/sandbox/chromium/base/cpu.cc@b8a032363ba2 (annotated)

security/sandbox/chromium/base/cpu.cc