On Tue, Dec 13, 2022 at 01:03:17PM -0500, Peter Jones wrote:
> On Tue, Nov 22, 2022 at 02:12:09PM +0300, Evgeniy Baskov wrote:
> > This patchset is aimed
> > * to improve UEFI compatibility of compressed kernel code for x86_64
> > * to setup proper memory access attributes for code and rodata sections
> > * to implement W^X protection policy throughout the whole execution
> > of compressed kernel for EFISTUB code path.
>
> Hi Evgeniy,
>
> I've tested this patch set on hardware and QEMU+MU firmware, and it
> works for me with a couple of minor issues:
>
> - on one machine that has the DXE protocol but not the EFI one, we get
> an error because the firmware doesn't support EFI_MEMORY_RP
> - on QEMU I'm seeing the size of "(unsigned long)_head - image_base"
> wind up as 0, which leads to an EFI_INVALID_PARAMETER on the
> clear_memory_attributes() call.
>
> In both cases the system winds up working, but with unnecessary console
> output.
I just realized I've overstated here - I haven't actually hit the first
problem on x86, only on ARM, where we don't currently use this code. I
discovered it in grub, and checked your patch set to see if you had the
same issue I did. That said, "in both cases the system winds up
working" is probably still true - in that the edk2 code supports
EFI_MEMORY_RP on x86 but not ARM, so x86 won't hit the issue when using
DXE unless someone cooks up another implementation. Nevertheless I
believe the patch to fix it is correct and should be applied.
Thanks!
--
Peter
