On 03/03/20 22:03, Laszlo Ersek wrote:
> On 03/03/20 15:01, Ard Biesheuvel wrote:
>> Before taking any actions, check if an instance of the LoadFile2 exists
>> already on the Linux initrd media GUID device path, and whether it was
>> provided by this command. If so, abort, since no duplicate instances of
>> the device path should exist.
>>
>> Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=2564
>> Signed-off-by: Ard Biesheuvel <ard.biesheu...@linaro.org>
>> ---
>> OvmfPkg/LinuxInitrdDynamicShellCommand/LinuxInitrdDynamicShellCommand.c |
>> 31 ++++++++++++++++++++
>> OvmfPkg/LinuxInitrdDynamicShellCommand/LinuxInitrdDynamicShellCommand.uni |
>> 3 ++
>> 2 files changed, 34 insertions(+)
>>
>> diff --git
>> a/OvmfPkg/LinuxInitrdDynamicShellCommand/LinuxInitrdDynamicShellCommand.c
>> b/OvmfPkg/LinuxInitrdDynamicShellCommand/LinuxInitrdDynamicShellCommand.c
>> index 47ed26b50d3a..ed8fbaa77069 100644
>> --- a/OvmfPkg/LinuxInitrdDynamicShellCommand/LinuxInitrdDynamicShellCommand.c
>> +++ b/OvmfPkg/LinuxInitrdDynamicShellCommand/LinuxInitrdDynamicShellCommand.c
>> @@ -53,6 +53,33 @@ STATIC CONST SINGLE_NODE_VENDOR_MEDIA_DEVPATH
>> mInitrdDevicePath = {
>> }
>> };
>>
>> +STATIC
>> +BOOLEAN
>> +IsOtherInitrdDevicePathAlreadyInstalled (
>> + VOID
>> + )
>> +{
>> + EFI_STATUS Status;
>> + EFI_DEVICE_PATH_PROTOCOL *DevicePath;
>> + EFI_HANDLE Handle;
>> +
>> + DevicePath = (EFI_DEVICE_PATH_PROTOCOL *)&mInitrdDevicePath;
>> + Status = gBS->LocateDevicePath (&gEfiLoadFile2ProtocolGuid, &DevicePath,
>> + &Handle);
>> + if (EFI_ERROR (Status)) {
>> + return FALSE;
>> + }
>> +
>> + //
>> + // Check whether the existing instance is one that we installed during
>> + // a previous invocation.
>> + //
>> + if (Handle == mInitrdLoadFile2Handle) {
>> + return FALSE;
>> + }
>> + return TRUE;
>> +}
>
> Looks good, the function will return TRUE when mInitrdLoadFile2Handle is
> NULL.
To clarify, what I mean is that the controlling expression
(Handle == mInitrdLoadFile2Handle)
assuming it is reached, will evaluate to 0, if mInitrdLoadFile2Handle is
NULL. That's because Handle cannot be NULL at that point. Hence the
function will return TRUE.
Thanks
Laszlo
> Reviewed-by: Laszlo Ersek <ler...@redhat.com>
>
> Thanks
> Laszlo
>
>
>> +
>> STATIC
>> EFI_STATUS
>> EFIAPI
>> @@ -217,6 +244,10 @@ RunInitrd (
>> } else {
>> ASSERT(FALSE);
>> }
>> + } else if (IsOtherInitrdDevicePathAlreadyInstalled ()) {
>> + ShellPrintHiiEx (-1, -1, NULL, STRING_TOKEN (STR_GEN_ALREADY_INSTALLED),
>> + mLinuxInitrdShellCommandHiiHandle, L"initrd");
>> + ShellStatus = SHELL_UNSUPPORTED;
>> } else {
>> if (ShellCommandLineGetCount (Package) > 2) {
>> ShellPrintHiiEx (-1, -1, NULL, STRING_TOKEN (STR_GEN_TOO_MANY),
>> diff --git
>> a/OvmfPkg/LinuxInitrdDynamicShellCommand/LinuxInitrdDynamicShellCommand.uni
>> b/OvmfPkg/LinuxInitrdDynamicShellCommand/LinuxInitrdDynamicShellCommand.uni
>> index a88fa6e3641b..4b6b1285fffd 100644
>> ---
>> a/OvmfPkg/LinuxInitrdDynamicShellCommand/LinuxInitrdDynamicShellCommand.uni
>> +++
>> b/OvmfPkg/LinuxInitrdDynamicShellCommand/LinuxInitrdDynamicShellCommand.uni
>> @@ -18,6 +18,7 @@
>> #langdef en-US "english"
>>
>> #string STR_GEN_PROBLEM #language en-US "%H%s%N: Unknown flag -
>> '%H%s%N'\r\n"
>> +#string STR_GEN_ALREADY_INSTALLED #language en-US "%H%s%N: Linux initrd
>> already provided by platform\r\n"
>> #string STR_GEN_TOO_MANY #language en-US "%H%s%N: Too many
>> arguments.\r\n"
>> #string STR_GEN_TOO_FEW #language en-US "%H%s%N: Too few
>> arguments.\r\n"
>> #string STR_GEN_FIND_FAIL #language en-US "%H%s%N: File not found -
>> '%H%s%N'\r\n"
>> @@ -47,3 +48,5 @@
>> " Consumers of the LoadFile2 protocol on the
>> LINUX_EFI_INITRD_MEDIA_GUID\r\n"
>> " device path that are started via means other than the shell will be
>> able\r\n"
>> " to locate the protocol and invoke it.\r\n"
>> +" 3. Exposing an initrd using this command is only supported if no initrd
>> is\r\n"
>> +" already being exposed by another driver on the platform.\r\n"
>>
>
-=-=-=-=-=-=-=-=-=-=-=-
Groups.io Links: You receive all messages sent to this group.
View/Reply Online (#55345): https://edk2.groups.io/g/devel/message/55345
Mute This Topic: https://groups.io/mt/71700589/21656
Group Owner: devel+ow...@edk2.groups.io
Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com]
-=-=-=-=-=-=-=-=-=-=-=-
