Re: [PATCH 3/4] mm/rmap: fix new bug: premature return from page_mlock_one()

From: Shakeel Butt
Date: Wed Jul 07 2021 - 16:22:50 EST


On Wed, Jul 7, 2021 at 1:11 PM Hugh Dickins <hughd@xxxxxxxxxx> wrote:
>
> In the unlikely race case that page_mlock_one() finds VM_LOCKED has been
> cleared by the time it got page table lock, page_vma_mapped_walk_done()
> must be called before returning, either explicitly, or by a final call
> to page_vma_mapped_walk() - otherwise the page table remains locked.
>
> Fixes: cd62734ca60d ("mm/rmap: split try_to_munlock from try_to_unmap")
> Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx>

Reviewed-by: Shakeel Butt <shakeelb@xxxxxxxxxx>