Re: [PATCH v4 0/7] mm/mprotect: Fix dax puds

Andrew Morton
2024-08-07T21:23:18Z

On Wed, 7 Aug 2024 15:48:04 -0400 Peter Xu <peterx@redhat.com> wrote:

>
> Tests
> =====
>
> What I did test:
>
> - cross-build tests that I normally cover [1]
>
> - smoke tested on x86_64 the simplest program [2] on dev_dax 1G PUD
> mprotect() using QEMU's nvdimm emulations [3] and ndctl to create
> namespaces with proper alignments, which used to throw "bad pud" but now
> it'll run through all fine. I checked sigbus happens if with illegal
> access on protected puds.
>
> - vmtests.
>
> What I didn't test:
>
> - fsdax: I wanted to also give it a shot, but only until then I noticed it
> doesn't seem to be supported (according to dax_iomap_fault(), which will
> always fallback on PUD_ORDER). I did remember it was supported before, I
> could miss something important there.. please shoot if so.

OK. Who are you addressing this question to?

> - userfault wp-async: I also wanted to test userfault-wp async be able to
> split huge puds (here it's simply a clear_pud.. though), but it won't
> work for devdax anyway due to not allowed to do smaller than 1G faults in
> this case. So skip too.

Sounds OK. So that's an additional project if anyone cares enough?

> - Power, as no hardware on hand.

Hopefully the powerpc people can help with that. What tests do you ask
that they run?