Re: Fwd: Memory corruption in multithreaded user space program while calling fork

From: Suren Baghdasaryan
Date: Sat Jul 08 2023 - 15:42:46 EST


On Sat, Jul 8, 2023 at 12:23 PM Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> On Sat, 8 Jul 2023 at 12:17, Suren Baghdasaryan <surenb@xxxxxxxxxx> wrote:
> >
> > Do you want me to disable per-VMA locks by default as well?
>
> No. I seriously believe that if the per-vma locking is so broken that
> it needs to be disabled in a development kernel, we should just admit
> failure, and revert it all.
>
> And not in a "revert it for a later attempt" kind of way.
>
> So it would be a "revert it because it added insurmountable problems
> that we couldn't figure out" thing that implies *not* trying it again
> in that form at all, and much soul-searching before somebody decides
> that they have a more maintainable model for it all.

Got it. I hope that's not the case and so far we haven't received an
indication that the fixes were insufficient.

>
> If stable decides that the fixes are not back-portable, and the whole
> thing needs to be disabled for stable, that's one thing. But if we
> decide that in mainline, it's a "this was a failure" thing.

The patches applied cleanly to 6.4.y stable branch the last time I
checked, so should not be a problem.
Thanks,
Suren.

>
> Linus