Re: [edk2-devel] [RFC PATCH 2/3] MdeModulePkg: Enable forward edge CFI in mem attributes table

["Marvin Häuser" <mhaeuser@posteo.de>]

Sorry, forgot to ask (and it’s probably obvious), but there is a sane tag for ELFs that could be translated to the potential new PE tag, right? For both GCC and Clang builds?

> On 3. Feb 2023, at 09:28, Ard Biesheuvel <ardb@kernel.org> wrote:
> 
> On Fri, 3 Feb 2023 at 09:25, Marvin Häuser <mhaeuser@posteo.de> wrote:
>> 
>> Hi Ard,
>> 
>> Short story: No, TE is not a concern for RT drivers, at least not upstream [1].
>> 
>> Long story: Even if a downstream added support for RT relocation itself, TE images are loaded misaligned by DxeCore, because it lacks a (terrible) workaround as done in PeiCore [2]. It doesn’t look like anyone tried to use them in DXE at all.
>> 
>> Best regards,
>> Marvin
>> 
>> [1] https://github.com/tianocore/edk2/blob/11f0014c0e3046e3762eac420b760091d0cdc063/MdePkg/Library/BasePeCoffLib/BasePeCoff.c#L1759
>> 
>> [2] https://github.com/tianocore/edk2/blob/11f0014c0e3046e3762eac420b760091d0cdc063/MdeModulePkg/Core/Pei/Image/Image.c#L412
> 
> Ah thanks for digging that up.
> 
> So all the more reason to add this to the PE/COFF spec rather than
> anywhere else.