Re: [edk2-devel] [PATCH 4/4] ArmPkg/CpuDxe: Implement EFI memory attributes protocol

["Taylor Beebe" <t@taylorbeebe.com>]

I can't see the Bugzilla you referenced so I requested security Bugzilla 
access. But, yes, that's the bug to which I was referring :)

Once Ard's change to add Memory Attribute Protocol support to ARM 
platforms is in, the change you linked may be palatable for the 
upstream. However, ARM platforms could run into the infinite loop I 
outlined if that change is pushed upstream because of the lack of 
per-allocated page tables and a software semaphore to prevent looping.

I implemented pre-allocated pages for ARM a while back in a private repo 
but never committed it to Mu. Maybe that would also be worth committing 
and pushing upstream.

-Taylor

On 2/3/2023 11:58 AM, Marvin Häuser wrote:
> Hi Taylor,
> 
> Do you by any chance mean this bug? 
> https://github.com/microsoft/mu_basecore/blob/release/202208/MdeModulePkg/Core/Dxe/Misc/MemoryProtection.c#L1544 <https://github.com/microsoft/mu_basecore/blob/release/202208/MdeModulePkg/Core/Dxe/Misc/MemoryProtection.c#L1544>
> 
> I reported this a while ago at 
> https://bugzilla.tianocore.org/show_bug.cgi?id=3316 
> <https://bugzilla.tianocore.org/show_bug.cgi?id=3316>
> 
> The Mu fix is by no means a workaround and actually fixes this issue in 
> a sane way. It should have been fixed upstream ages ago.
> 
> Best regards,
> Marvin
>