text: /** @file
    CopyMem() implementation.
  
    The following BaseMemoryLib instances contain the same copy of this file:
  
      BaseMemoryLib
      BaseMemoryLibMmx
      BaseMemoryLibSse2
      BaseMemoryLibRepStr
      BaseMemoryLibOptDxe
      BaseMemoryLibOptPei
      PeiMemoryLib
      UefiMemoryLib
  
    Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
    SPDX-License-Identifier: BSD-2-Clause-Patent
  
  **/
  
  #include "MemLibInternals.h"
  
  /**
    Copies a source buffer to a destination buffer, and returns the destination buffer.
  
    This function copies Length bytes from SourceBuffer to DestinationBuffer, and returns
    DestinationBuffer.  The implementation must be reentrant, and it must handle the case
    where SourceBuffer overlaps DestinationBuffer.
  
    If Length is greater than (MAX_ADDRESS - DestinationBuffer + 1), then ASSERT().
    If Length is greater than (MAX_ADDRESS - SourceBuffer + 1), then ASSERT().
  
    @param  DestinationBuffer   The pointer to the destination buffer of the memory copy.
    @param  SourceBuffer        The pointer to the source buffer of the memory copy.
    @param  Length              The number of bytes to copy from SourceBuffer to DestinationBuffer.
  
    @return DestinationBuffer.
  
  **/
  VOID *
  EFIAPI
  CopyMem (
    OUT VOID       *DestinationBuffer,
    IN CONST VOID  *SourceBuffer,
    IN UINTN       Length
    )
  {
    if (Length == 0) {
      return DestinationBuffer;
    }
    ASSERT ((Length - 1) <= (MAX_ADDRESS - (UINTN)DestinationBuffer));
    ASSERT ((Length - 1) <= (MAX_ADDRESS - (UINTN)SourceBuffer));
  
    if (DestinationBuffer == SourceBuffer) {
      return DestinationBuffer;
    }
  
  #ifdef SANITIZE_SMM_MSAN
    __msan_transfer_shadow(DestinationBuffer, (void *)SourceBuffer, Length);
    __msan_unpoison_param(3);
  #endif
  #ifdef SANITIZE_SMM_ASAN
    __asan_read_range(SourceBuffer, Length);
    __asan_write_range(DestinationBuffer, Length);
  #endif
  
    return InternalMemCopyMem (DestinationBuffer, SourceBuffer, Length);
  }
  