Re: [PATCH v3 2/2] mm: disable CONFIG_PER_VMA_LOCK until its fixed

[David Hildenbrand]

On 05.07.23 19:22, Suren Baghdasaryan wrote:
> On Wed, Jul 5, 2023 at 10:16 AM David Hildenbrand <david@xxxxxxxxxx> wrote:
> > On 05.07.23 19:12, Suren Baghdasaryan wrote:
> > > A memory corruption was reported in [1] with bisection pointing to the
> > > patch [2] enabling per-VMA locks for x86.
> > > Disable per-VMA locks config to prevent this issue while the problem is
> > > being investigated. This is expected to be a temporary measure.
> > >
> > > [1] https://bugzilla.kernel.org/show_bug.cgi?id=217624
> > > [2] https://lore.kernel.org/all/20230227173632.3292573-30-surenb@xxxxxxxxxx
> > >
> > > Reported-by: Jiri Slaby <jirislaby@xxxxxxxxxx>
> > > Closes: https://lore.kernel.org/all/dbdef34c-3a07-5951-e1ae-e9c6e3cdf51b@xxxxxxxxxx/
> > > Reported-by: Jacob Young <jacobly.alt@xxxxxxxxx>
> > > Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217624
> > > Fixes: 0bff0aaea03e ("x86/mm: try VMA lock-based page fault handling first")
> > > Cc: stable@xxxxxxxxxxxxxxx
> > > Signed-off-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>
> > > ---
> > >    mm/Kconfig | 3 ++-
> > >    1 file changed, 2 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/mm/Kconfig b/mm/Kconfig
> > > index 09130434e30d..0abc6c71dd89 100644
> > > --- a/mm/Kconfig
> > > +++ b/mm/Kconfig
> > > @@ -1224,8 +1224,9 @@ config ARCH_SUPPORTS_PER_VMA_LOCK
> > >           def_bool n
> > >
> > >    config PER_VMA_LOCK
> > > -     def_bool y
> > > +     bool "Enable per-vma locking during page fault handling."
> > >        depends on ARCH_SUPPORTS_PER_VMA_LOCK && MMU && SMP
> > > +     depends on BROKEN
> > >        help
> > >          Allow per-vma locking during page fault handling.
> > Do we have any testing results (that don't reveal other issues :) ) for
> > patch #1? Not sure if we really want to mark it broken if patch #1 fixes
> > the issue.
>
> I tested the fix using the only reproducer provided in the reports
> plus kernel compilation and my fork stress test. All looked good and
> stable but I don't know if other reports had the same issue or
> something different.

Can you point me at the other reports, so I can quickly scan them?

--
Cheers,

David / dhildenb