On 8/2/17 4:24 PM, Laszlo Ersek wrote:
[Snip] > At the moment, we have the foll+ // The buffer at MapInfo->CryptedAddress > comes from AllocateBuffer(). > // > MapInfo->PlainTextAddress = MapInfo->CryptedAddress; > - > // > - // Therefore no mapping is necessary. > + // Stash the crypted data. > // > - *DeviceAddress = MapInfo->PlainTextAddress; > - *Mapping = NO_MAPPING; > - FreePool (MapInfo); > - return EFI_SUCCESS; > + CommonBufferHeader = (COMMON_BUFFER_HEADER *)( > + (UINTN)MapInfo->CryptedAddress - EFI_PAGE_SIZE > + ); One question, per spec, is it legal for client to call Map() at some offset within allocated buffer ? e.g something like this: * AllocateBuffer (, 1, &Buffer); * MapBuffer = Buffer + 10; * Map (, BusMasterCommonBuffer, MappedBuffer, 10, ..) // Bascially Map 10 bytes from offset 10 If this is legal then we may need to build MapInfo during AllocateBuffer() to locate the "StashBuffer". So far, I have not came across this usecase but I wanted to check with you so that we don't fail on corner cases. Good part if you have ASSERT() so we should be able to catch them (if any). > + ASSERT (CommonBufferHeader->Signature == COMMON_BUFFER_SIG); > + CopyMem ( > + CommonBufferHeader->StashBuffer, > + (VOID *)(UINTN)MapInfo->CryptedAddress, > + MapInfo->NumberOfBytes > + ); > + // > + // Point "DecryptionSource" to the stash buffer so that we decrypt > + // it to the original location, after the switch statement. > + // > + DecryptionSource = CommonBufferHeader->StashBuffer; > + break; > [Snip] _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
