Re: [PATCH v2] mm: Fix memory ordering for mm_lock_seq and vm_lock_seq

From: Jann Horn
Date: Mon Jul 24 2023 - 13:29:56 EST


On Mon, Jul 24, 2023 at 7:11 PM Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
> On Sat, 22 Jul 2023 00:51:07 +0200 Jann Horn <jannh@xxxxxxxxxx> wrote:
> > BACKPORT WARNING: One of the functions changed by this patch (which I've
> > written against Linus' tree) is vma_try_start_write(), but this function
> > no longer exists in mm/mm-everything. I don't know whether the merged
> > version of this patch will be ordered before or after the patch that
> > removes vma_try_start_write(). If you're backporting this patch to a
> > tree with vma_try_start_write(), make sure this patch changes that
> > function.
>
> I staged this patch as a hotfix, ahead of mm-unstable material.
>
> The conflict is with Hugh's "mm: delete mmap_write_trylock() and
> vma_try_start_write()"
> (https://lkml.kernel.org/r/4e6db3d-e8e-73fb-1f2a-8de2dab2a87c@xxxxxxxxxx)
>
> I fixed the reject in the obvious way (deleted the function anyway),
> but there's a possibility that the ordering issue you have addressed
> will now be reintroduced by Hugh's series, so please let's review that.

Thanks. I've looked at Hugh's series and what you did (deleting the
function anyway) looks good to me.