Method CodeBuffer

FEXCore/Source/Interface/Core/CPUBackend.cpp:348–361

  }

  CodeBuffer::CodeBuffer(size_t Size)
    : Size(Size) {
    Ptr = static_cast<uint8_t*>(FEXCore::Allocator::VirtualAlloc(Size, true));
    LOGMAN_THROW_A_FMT(!!Ptr, "Couldn't allocate code buffer");

    // Protect the last page of the allocated buffer to trigger SIGSEGV on write access
    uintptr_t LastPageAddr = AlignDown(reinterpret_cast<uintptr_t>(Ptr) + Size - 1, FEXCore::Utils::FEX_PAGE_SIZE);
    if (!FEXCore::Allocator::VirtualProtect(reinterpret_cast<void*>(LastPageAddr), FEXCore::Utils::FEX_PAGE_SIZE,
                                            FEXCore::Allocator::ProtectOptions::None)) {
      LogMan::Msg::EFmt("Failed to mprotect last page of code buffer.");
    }

    LookupCache = fextl::make_unique<GuestToHostMap>();
  }

  CodeBuffer::~CodeBuffer() {
    FEXCore::Allocator::VirtualFree(Ptr, Size);