100 lines · cpp
1//===-- checksum.cpp --------------------------------------------*- C++ -*-===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9#include "checksum.h"10#include "atomic_helpers.h"11#include "chunk.h"12 13#if defined(__x86_64__) || defined(__i386__)14#include <cpuid.h>15#elif defined(__arm__) || defined(__aarch64__)16#if SCUDO_FUCHSIA17#include <zircon/features.h>18#include <zircon/syscalls.h>19#else20#include <sys/auxv.h>21#endif22#elif defined(__loongarch__)23#include <sys/auxv.h>24#endif25 26namespace scudo {27 28Checksum HashAlgorithm = {Checksum::BSD};29 30#if defined(__x86_64__) || defined(__i386__)31// i386 and x86_64 specific code to detect CRC32 hardware support via CPUID.32// CRC32 requires the SSE 4.2 instruction set.33#ifndef bit_SSE4_234#define bit_SSE4_2 bit_SSE42 // clang and gcc have different defines.35#endif36 37#ifndef signature_HYGON_ebx // They are not defined in gcc.38// HYGON: "HygonGenuine".39#define signature_HYGON_ebx 0x6f67794840#define signature_HYGON_edx 0x6e65476e41#define signature_HYGON_ecx 0x656e697542#endif43 44bool hasHardwareCRC32() {45 u32 Eax, Ebx = 0, Ecx = 0, Edx = 0;46 __get_cpuid(0, &Eax, &Ebx, &Ecx, &Edx);47 const bool IsIntel = (Ebx == signature_INTEL_ebx) &&48 (Edx == signature_INTEL_edx) &&49 (Ecx == signature_INTEL_ecx);50 const bool IsAMD = (Ebx == signature_AMD_ebx) && (Edx == signature_AMD_edx) &&51 (Ecx == signature_AMD_ecx);52 const bool IsHygon = (Ebx == signature_HYGON_ebx) &&53 (Edx == signature_HYGON_edx) &&54 (Ecx == signature_HYGON_ecx);55 if (!IsIntel && !IsAMD && !IsHygon)56 return false;57 __get_cpuid(1, &Eax, &Ebx, &Ecx, &Edx);58 return !!(Ecx & bit_SSE4_2);59}60#elif defined(__arm__) || defined(__aarch64__)61#ifndef AT_HWCAP62#define AT_HWCAP 1663#endif64#ifndef HWCAP_CRC3265#define HWCAP_CRC32 (1U << 7) // HWCAP_CRC32 is missing on older platforms.66#endif67 68bool hasHardwareCRC32() {69#if SCUDO_FUCHSIA70 u32 HWCap;71 const zx_status_t Status =72 zx_system_get_features(ZX_FEATURE_KIND_CPU, &HWCap);73 if (Status != ZX_OK)74 return false;75 return !!(HWCap & ZX_ARM64_FEATURE_ISA_CRC32);76#else77 return !!(getauxval(AT_HWCAP) & HWCAP_CRC32);78#endif // SCUDO_FUCHSIA79}80#elif defined(__loongarch__)81// The definition is only pulled in by <sys/auxv.h> since glibc 2.38, so82// supply it if missing.83#ifndef HWCAP_LOONGARCH_CRC3284#define HWCAP_LOONGARCH_CRC32 (1 << 6)85#endif86// Query HWCAP for platform capability, according to *Software Development and87// Build Convention for LoongArch Architectures* v0.1, Section 9.1.88//89// Link:90// https://github.com/loongson/la-softdev-convention/blob/v0.1/la-softdev-convention.adoc#kernel-development91bool hasHardwareCRC32() {92 return !!(getauxval(AT_HWCAP) & HWCAP_LOONGARCH_CRC32);93}94#else95// No hardware CRC32 implemented in Scudo for other architectures.96bool hasHardwareCRC32() { return false; }97#endif // defined(__x86_64__) || defined(__i386__)98 99} // namespace scudo100