Re: [PATCH v7 4/7] mseal, system mappings: enable arm64

[Jeff Xu]

On Mon, Feb 24, 2025 at 10:20 PM Lorenzo Stoakes
<lorenzo.stoakes@xxxxxxxxxx> wrote:
>
> On Mon, Feb 24, 2025 at 10:52:43PM +0000, jeffxu@xxxxxxxxxxxx wrote:
> > From: Jeff Xu <jeffxu@xxxxxxxxxxxx>
> >
> > Provide support for CONFIG_MSEAL_SYSTEM_MAPPINGS on arm64, covering
> > the vdso, vvar, and compat-mode vectors and sigpage mappings.
> >
> > Production release testing passes on Android and Chrome OS.
>
> This is pretty limited (yes yes I know android is massive etc. but we must
> account for all the weird and wonderful arm64 devices out there in context of
> upstream :)
>
> Have you looking through all arm64-code relating to vdso, vvar, compat-mode
> vectors, sigpage mapping and ensured nothing kernel-side relies upon relocation?
> Some arches actually seem to want to do this. Pretty sure PPC does... so a bit
> nervous of that.
>
Can you please point out where PPC munmap/mremap the vdso ?

Previously, when you mentioned that, I thought you meant user space in
PPC, I didn't realize that you meant that kernel code in PPC.  I
tried, but didn't find anything, hence asking.

Thanks.
-Jeff