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-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "checksum.h" 10 #include "atomic_helpers.h" 11 12 #if defined(__x86_64__) || defined(__i386__) 13 #include <cpuid.h> 14 #elif defined(__arm__) || defined(__aarch64__) 15 #if SCUDO_FUCHSIA 16 #include <zircon/features.h> 17 #include <zircon/syscalls.h> 18 #else 19 #include <sys/auxv.h> 20 #endif 21 #endif 22 23 namespace scudo { 24 25 Checksum HashAlgorithm = {Checksum::BSD}; 26 27 #if defined(__x86_64__) || defined(__i386__) 28 // i386 and x86_64 specific code to detect CRC32 hardware support via CPUID. 29 // CRC32 requires the SSE 4.2 instruction set. 30 #ifndef bit_SSE4_2 31 #define bit_SSE4_2 bit_SSE42 // clang and gcc have different defines. 32 #endif 33 34 bool hasHardwareCRC32() { 35 u32 Eax, Ebx = 0, Ecx = 0, Edx = 0; 36 __get_cpuid(0, &Eax, &Ebx, &Ecx, &Edx); 37 const bool IsIntel = (Ebx == signature_INTEL_ebx) && 38 (Edx == signature_INTEL_edx) && 39 (Ecx == signature_INTEL_ecx); 40 const bool IsAMD = (Ebx == signature_AMD_ebx) && (Edx == signature_AMD_edx) && 41 (Ecx == signature_AMD_ecx); 42 if (!IsIntel && !IsAMD) 43 return false; 44 __get_cpuid(1, &Eax, &Ebx, &Ecx, &Edx); 45 return !!(Ecx & bit_SSE4_2); 46 } 47 #elif defined(__arm__) || defined(__aarch64__) 48 #ifndef AT_HWCAP 49 #define AT_HWCAP 16 50 #endif 51 #ifndef HWCAP_CRC32 52 #define HWCAP_CRC32 (1U << 7) // HWCAP_CRC32 is missing on older platforms. 53 #endif 54 55 bool hasHardwareCRC32() { 56 #if SCUDO_FUCHSIA 57 u32 HWCap; 58 const zx_status_t Status = 59 zx_system_get_features(ZX_FEATURE_KIND_CPU, &HWCap); 60 if (Status != ZX_OK) 61 return false; 62 return !!(HWCap & ZX_ARM64_FEATURE_ISA_CRC32); 63 #else 64 return !!(getauxval(AT_HWCAP) & HWCAP_CRC32); 65 #endif // SCUDO_FUCHSIA 66 } 67 #else 68 // No hardware CRC32 implemented in Scudo for other architectures. 69 bool hasHardwareCRC32() { return false; } 70 #endif // defined(__x86_64__) || defined(__i386__) 71 72 } // namespace scudo 73