forked from OSchip/llvm-project
127 lines
3.3 KiB
C++
127 lines
3.3 KiB
C++
//===-- scudo_utils.cpp -----------------------------------------*- C++ -*-===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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///
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/// Platform specific utility functions.
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///
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//===----------------------------------------------------------------------===//
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#include "scudo_utils.h"
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#include <errno.h>
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#include <fcntl.h>
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#include <stdarg.h>
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#include <unistd.h>
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#if defined(__x86_64__) || defined(__i386__)
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# include <cpuid.h>
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#endif
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#if defined(__arm__) || defined(__aarch64__)
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# include <sys/auxv.h>
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#endif
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// TODO(kostyak): remove __sanitizer *Printf uses in favor for our own less
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// complicated string formatting code. The following is a
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// temporary workaround to be able to use __sanitizer::VSNPrintf.
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namespace __sanitizer {
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extern int VSNPrintf(char *buff, int buff_length, const char *format,
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va_list args);
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} // namespace __sanitizer
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namespace __scudo {
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FORMAT(1, 2)
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void NORETURN dieWithMessage(const char *Format, ...) {
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// Our messages are tiny, 256 characters is more than enough.
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char Message[256];
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va_list Args;
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va_start(Args, Format);
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__sanitizer::VSNPrintf(Message, sizeof(Message), Format, Args);
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va_end(Args);
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RawWrite(Message);
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Die();
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}
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#if defined(__x86_64__) || defined(__i386__)
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// i386 and x86_64 specific code to detect CRC32 hardware support via CPUID.
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// CRC32 requires the SSE 4.2 instruction set.
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typedef struct {
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u32 Eax;
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u32 Ebx;
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u32 Ecx;
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u32 Edx;
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} CPUIDRegs;
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static void getCPUID(CPUIDRegs *Regs, u32 Level)
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{
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__get_cpuid(Level, &Regs->Eax, &Regs->Ebx, &Regs->Ecx, &Regs->Edx);
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}
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CPUIDRegs getCPUFeatures() {
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CPUIDRegs VendorRegs = {};
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getCPUID(&VendorRegs, 0);
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bool IsIntel =
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(VendorRegs.Ebx == signature_INTEL_ebx) &&
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(VendorRegs.Edx == signature_INTEL_edx) &&
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(VendorRegs.Ecx == signature_INTEL_ecx);
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bool IsAMD =
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(VendorRegs.Ebx == signature_AMD_ebx) &&
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(VendorRegs.Edx == signature_AMD_edx) &&
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(VendorRegs.Ecx == signature_AMD_ecx);
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// Default to an empty feature set if not on a supported CPU.
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CPUIDRegs FeaturesRegs = {};
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if (IsIntel || IsAMD) {
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getCPUID(&FeaturesRegs, 1);
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}
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return FeaturesRegs;
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}
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#ifndef bit_SSE4_2
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# define bit_SSE4_2 bit_SSE42 // clang and gcc have different defines.
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#endif
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bool testCPUFeature(CPUFeature Feature)
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{
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CPUIDRegs FeaturesRegs = getCPUFeatures();
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switch (Feature) {
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case CRC32CPUFeature: // CRC32 is provided by SSE 4.2.
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return !!(FeaturesRegs.Ecx & bit_SSE4_2);
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default:
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break;
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}
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return false;
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}
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#elif defined(__arm__) || defined(__aarch64__)
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// For ARM and AArch64, hardware CRC32 support is indicated in the
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// AT_HWVAL auxiliary vector.
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#ifndef HWCAP_CRC32
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# define HWCAP_CRC32 (1<<7) // HWCAP_CRC32 is missing on older platforms.
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#endif
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bool testCPUFeature(CPUFeature Feature) {
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uptr HWCap = getauxval(AT_HWCAP);
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switch (Feature) {
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case CRC32CPUFeature:
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return !!(HWCap & HWCAP_CRC32);
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default:
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break;
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}
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return false;
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}
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#else
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bool testCPUFeature(CPUFeature Feature) {
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return false;
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}
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#endif // defined(__x86_64__) || defined(__i386__)
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} // namespace __scudo
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