Ejemplo n.º 1
0
  // Allocates a chunk.
  void *allocate(uptr Size, uptr Alignment, AllocType Type) {
    if (UNLIKELY(!ThreadInited))
      initThread();
    if (!IsPowerOfTwo(Alignment)) {
      dieWithMessage("ERROR: malloc alignment is not a power of 2\n");
    }
    if (Alignment > MaxAlignment)
      return BackendAllocator.ReturnNullOrDie();
    if (Alignment < MinAlignment)
      Alignment = MinAlignment;
    if (Size == 0)
      Size = 1;
    if (Size >= MaxAllowedMallocSize)
      return BackendAllocator.ReturnNullOrDie();
    uptr RoundedSize = RoundUpTo(Size, MinAlignment);
    uptr ExtraBytes = ChunkHeaderSize;
    if (Alignment > MinAlignment)
      ExtraBytes += Alignment;
    uptr NeededSize = RoundedSize + ExtraBytes;
    if (NeededSize >= MaxAllowedMallocSize)
      return BackendAllocator.ReturnNullOrDie();

    void *Ptr;
    if (LIKELY(!ThreadTornDown)) {
      Ptr = BackendAllocator.Allocate(&Cache, NeededSize, MinAlignment);
    } else {
      SpinMutexLock l(&FallbackMutex);
      Ptr = BackendAllocator.Allocate(&FallbackAllocatorCache, NeededSize,
                               MinAlignment);
    }
    if (!Ptr)
      return BackendAllocator.ReturnNullOrDie();

    // If requested, we will zero out the entire contents of the returned chunk.
    if (ZeroContents && BackendAllocator.FromPrimary(Ptr))
       memset(Ptr, 0, BackendAllocator.GetActuallyAllocatedSize(Ptr));

    uptr AllocBeg = reinterpret_cast<uptr>(Ptr);
    uptr ChunkBeg = AllocBeg + ChunkHeaderSize;
    if (!IsAligned(ChunkBeg, Alignment))
      ChunkBeg = RoundUpTo(ChunkBeg, Alignment);
    CHECK_LE(ChunkBeg + Size, AllocBeg + NeededSize);
    ScudoChunk *Chunk =
        reinterpret_cast<ScudoChunk *>(ChunkBeg - ChunkHeaderSize);
    UnpackedHeader Header = {};
    Header.State = ChunkAllocated;
    Header.Offset = (ChunkBeg - ChunkHeaderSize - AllocBeg) >> MinAlignmentLog;
    Header.AllocType = Type;
    Header.RequestedSize = Size;
    Header.Salt = static_cast<u16>(Prng.Next());
    Chunk->storeHeader(&Header);
    void *UserPtr = reinterpret_cast<void *>(ChunkBeg);
    // TODO(kostyak): hooks sound like a terrible idea security wise but might
    //                be needed for things to work properly?
    // if (&__sanitizer_malloc_hook) __sanitizer_malloc_hook(UserPtr, Size);
    return UserPtr;
  }
Ejemplo n.º 2
0
void *hwasan_pvalloc(uptr size, StackTrace *stack) {
  uptr PageSize = GetPageSizeCached();
  if (UNLIKELY(CheckForPvallocOverflow(size, PageSize))) {
    errno = errno_ENOMEM;
    if (AllocatorMayReturnNull())
      return nullptr;
    ReportPvallocOverflow(size, stack);
  }
  // pvalloc(0) should allocate one page.
  size = size ? RoundUpTo(size, PageSize) : PageSize;
  return SetErrnoOnNull(HwasanAllocate(stack, size, PageSize, false));
}
Ejemplo n.º 3
0
static uptr TaggedSize(uptr size) {
  if (!size) size = 1;
  uptr new_size = RoundUpTo(size, kShadowAlignment);
  CHECK_GE(new_size, size);
  return new_size;
}