compiler-rt/lib/scudo/standalone/checksum.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-exception
   6 //
   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_FUCHSIA
  17 #include <zircon/features.h>
  18 #include <zircon/syscalls.h>
  19 #else
  20 #include <sys/auxv.h>
  21 #endif
  22 #elif defined(__loongarch__)
  23 #include <sys/auxv.h>
  24 #endif
  25
  26 namespace scudo {
  27
  28 Checksum 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_2
  34 #define bit_SSE4_2 bit_SSE42 // clang and gcc have different defines.
  35 #endif
  36
  37 #ifndef signature_HYGON_ebx // They are not defined in gcc.
  38 // HYGON: "HygonGenuine".
  39 #define signature_HYGON_ebx 0x6f677948
  40 #define signature_HYGON_edx 0x6e65476e
  41 #define signature_HYGON_ecx 0x656e6975
  42 #endif
  43
  44 bool 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_HWCAP
  62 #define AT_HWCAP 16
  63 #endif
  64 #ifndef HWCAP_CRC32
  65 #define HWCAP_CRC32 (1U << 7) // HWCAP_CRC32 is missing on older platforms.
  66 #endif
  67
  68 bool hasHardwareCRC32() {
  69 #if SCUDO_FUCHSIA
  70   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 #else
  77   return !!(getauxval(AT_HWCAP) & HWCAP_CRC32);
  78 #endif // SCUDO_FUCHSIA
  79 }
  80 #elif defined(__loongarch__)
  81 // The definition is only pulled in by <sys/auxv.h> since glibc 2.38, so
  82 // supply it if missing.
  83 #ifndef HWCAP_LOONGARCH_CRC32
  84 #define HWCAP_LOONGARCH_CRC32 (1 << 6)
  85 #endif
  86 // Query HWCAP for platform capability, according to *Software Development and
  87 // 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-development
  91 bool hasHardwareCRC32() {
  92   return !!(getauxval(AT_HWCAP) & HWCAP_LOONGARCH_CRC32);
  93 }
  94 #else
  95 // No hardware CRC32 implemented in Scudo for other architectures.
  96 bool hasHardwareCRC32() { return false; }
  97 #endif // defined(__x86_64__) || defined(__i386__)
  98
  99 } // namespace scudo