Re: [MdeModulePkg] SetVirtualAddressMap() crashed due to DxeReportStatusCodeLib assuming the state of the BootService Memory at runtime.

["Zeng, Star" <star.zeng@intel.com>]

On 2016/8/9 10:07, Andrew Fish wrote:
>
>> On Aug 8, 2016, at 6:21 PM, Zeng, Star <star.zeng@intel.com> wrote:
>>
>> Andrew,
>>
>> Should MdeModulePkg/Library/RuntimeDxeReportStatusCodeLib be used for your case if there are really runtime status code reporting needed?
>>
>
> Star,
>
> If the Library instance does not fully support DXE_RUNTIME_DRIVER, why is it listed in the LIBRARY_CLASS as supported?

This kind of library can support DXE_RUNTIME_DRIVER at boot time, for 
example UefiHiiLib, UefiHiiServicesLib, UefiBootServicesTableLib, 
DxePcdLib and etc.

>
> https://github.com/tianocore/edk2/blob/master/MdeModulePkg/Library/DxeReportStatusCodeLib/DxeReportStatusCodeLib.inf#L25
>
>  LIBRARY_CLASS                  = ReportStatusCodeLib|DXE_CORE DXE_DRIVER DXE_RUNTIME_DRIVER DXE_SAL_DRIVER DXE_SMM_DRIVER UEFI_APPLICATION UEFI_DRIVER SMM_CORE
>
> Actually I tried to add the UefiRuntimeDriverLib and the build failed as UefiRuntimeDriverLib was not supported for the DXE_CORE type. Maybe the bug is this library instance lists DXE_RUNTIME_DRIVER,  DXE_SAL_DRIVER and DXE_SMM_DRIVER when it has special case code to support DXE_CORE? Maybe this library is trying to do too many things?
>
> What ReportStatusCodeLib would you recommend to link with RuntimeDxe driver: https://github.com/tianocore/edk2/blob/master/MdeModulePkg/Core/RuntimeDxe/RuntimeDxe.inf

[LibraryClasses.common.DXE_CORE]
 
ReportStatusCodeLib|MdeModulePkg/Library/DxeReportStatusCodeLib/DxeReportStatusCodeLib.inf

[LibraryClasses.common.DXE_RUNTIME_DRIVER]
 
ReportStatusCodeLib|MdeModulePkg/Library/RuntimeDxeReportStatusCodeLib/RuntimeDxeReportStatusCodeLib.inf

[LibraryClasses.common.UEFI_DRIVER]
 
ReportStatusCodeLib|MdeModulePkg/Library/DxeReportStatusCodeLib/DxeReportStatusCodeLib.inf

[LibraryClasses.common.DXE_DRIVER]
 
ReportStatusCodeLib|MdeModulePkg/Library/DxeReportStatusCodeLib/DxeReportStatusCodeLib.inf

[LibraryClasses.common.UEFI_APPLICATION]
 
ReportStatusCodeLib|MdeModulePkg/Library/DxeReportStatusCodeLib/DxeReportStatusCodeLib.inf

Thanks,
Star

>
> Thanks,
>
> Andrew Fish
>
>> Thanks,
>> Star
>> -----Original Message-----
>> From: edk2-devel [mailto:edk2-devel-bounces@lists.01.org] On Behalf Of Andrew Fish
>> Sent: Tuesday, August 9, 2016 7:08 AM
>> To: edk2-devel <edk2-devel@lists.01.org>
>> Subject: [edk2] [MdeModulePkg] SetVirtualAddressMap() crashed due to DxeReportStatusCodeLib assuming the state of the BootService Memory at runtime.
>>
>> I was messing about with an ExitBootServices test that fills boot services memory with 0xAFAFAFAFAFAFAFAF (It was Vincent's idea to use my Initials but it has the handy property of being a non-cononical address and causes on GP fault on X64) and SetVirtualAddressMap() started crashing.
>>
>> It looks like this code is assuming the 1st call to ReportStatus code will not happen at runtime. This is not the case for the RuntimeDxe driver.
>> https://github.com/tianocore/edk2/blob/master/MdeModulePkg/Library/DxeReportStatusCodeLib/ReportStatusCodeLib.c#L43
>> VOID
>> InternalGetReportStatusCode (
>> VOID
>> )
>> {
>> EFI_STATUS  Status;
>>
>> if (mReportStatusCodeLibStatusCodeProtocol != NULL) {
>>   return;
>> }
>>
>> //
>> // Check gBS just in case ReportStatusCode is called before gBS is initialized.
>> //
>> if (gBS != NULL && gBS->LocateProtocol != NULL) {
>>   Status = gBS->LocateProtocol (&gEfiStatusCodeRuntimeProtocolGuid, NULL, (VOID**) &mReportStatusCodeLibStatusCodeProtocol);
>>   if (EFI_ERROR (Status)) {
>>     mReportStatusCodeLibStatusCodeProtocol = NULL;
>>   }
>> }
>> }
>>
>> I'm guessing this seems to work due to:https://github.com/tianocore/edk2/blob/master/MdeModulePkg/Core/Dxe/DxeMain/DxeMain.c#L803
>>
>> //
>> // Zero out the Boot Service Table
>> //
>> ZeroMem (gBS, sizeof (EFI_BOOT_SERVICES));
>>
>>
>> Thus if I'm looking at this code correctly it only looks like it works at Runtime since it is depending on the value of a boot services memory buffer not changing. This is not a valid assumption as that code is owned by the caller of ExitBootServices, so it should be legal for my test to change the value.
>>
>> I wanted to get a few more eyes on this prior to filling a bug?
>>
>> Thanks,
>>
>> Andrew Fish
>>
>>
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