Re: [edk2-devel] [PATCH 1/2] ArmPkg/AsmMacroIoLibV8: Introduce ASM_FUNC_ALIGN()

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

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> On 19. Apr 2023, at 20:26, Ard Biesheuvel <ardb@kernel.org> wrote:
> 
> On Wed, 19 Apr 2023 at 20:25, Marvin Häuser <mhaeuser@posteo.de> wrote:
>> 
>> 
>> On 19. Apr 2023, at 20:03, Ard Biesheuvel <ardb@kernel.org> wrote:
>> 
>> Your branch seems to be missing 16e0969ef775b898ac700f3261d76030b8ab9ef0
>> 
>> "ArmVirtPkg/ArmVirtQemu: Use PEI flavor of ArmMmuLib for all PEIMs"
>> 
>> 
>> That's correct (because that commit is after the last commit I managed to reproduce the issue with), but I don't see how this commit would fix the issue. As I said, the symptom is that PeiCore memory is badly corrupted and the stall happens due to executing said corruption, not due to jumping to NULL. Those broken branches I linked can all be made work by rolling back the change to MemoryAllocationLib (which changes the code size, thus misaligns *something*). In fact, using the broken variant only for MemoryInitPei is sufficient to reproduce the issue, other modules don't seem to be involved.
>> 
> 
> Applying that commit made your branch work for me.

Yes, that might very well be - applying ae2c904 also "fixes" the issue as per https://github.com/mhaeuser/edk2/tree/arm_corruption-earliest-fixed

And technically, so does reverting this line :) https://github.com/mhaeuser/edk2/commit/7a96986e024f9c7ccf4774cc6f2ddb47a3abc86e#diff-1edfe01abdf8e4dcac640db4d9436e17b5f15d037714df7f365b58fcfc91e425R409

I don't understand how the changes would *fix* (rather than hide) the issue, so I'd attribute it to lucky codegen that doesn't misalign whatever is misaligned. I unfortunately have absolutely no time to get back to debugging this. :(

Best regards,
Marvin

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