Re: [PATCH 6.18.y v1 0/9] mm: backport sticky VMA flags and soft-dirty fix

[Lorenzo Stoakes <ljs@kernel.org>]

On Fri, May 15, 2026 at 12:44:55PM +0100, Lorenzo Stoakes wrote:
> Hi,
>
> Just a heads up that I generally don't read kernel mail sent to my work address,
> as I changed my email setup significantly and use ljs@kernel.org for everything
> upstream!
>
> Understandable given the original patches obviously used it but just FYI :)
>
> Cheers, Lorenzo
>
> On Sat, Apr 25, 2026 at 12:12:34AM +0300, Ahmed Elaidy wrote:
> > This series backports the sticky VMA flags infrastructure and the
> > VM_SOFTDIRTY-on-merge fix to linux-6.18.y.
> >
> > Motivation: CRIU incremental dump/restore can hit a missing-parent-pagemap
> > failure when VM_SOFTDIRTY is lost during VMA merge operations.
> >
> > Patch 8 is the target fix:
> >   mm: propagate VM_SOFTDIRTY on merge
> >
> > The preceding patches provide required dependencies on 6.18.y and are included
> > to preserve upstream behavior.
> >
> > Backport notes:
> >   - Non-trivial context conflicts were resolved in:
> >     - mm/mseal.c
> >     - mm/vma.c
> >   - Conflict resolution keeps upstream semantics; no intentional behavior
> >     changes beyond context adaptation for 6.18.y.

Thanks for doing this, had a quick look through the series and all LGTM!

Cheers, Lorenzo

> >
> > Cc: stable@vger.kernel.org
> >
> >
> >
> > Lorenzo Stoakes (9):
> >   mm: introduce VM_MAYBE_GUARD and make visible in /proc/$pid/smaps
> >   mm: add atomic VMA flags and set VM_MAYBE_GUARD as such
> >   mm: update vma_modify_flags() to handle residual flags, document
> >   mm: implement sticky VMA flags
> >   mm: introduce copy-on-fork VMAs and make VM_MAYBE_GUARD one
> >   mm: set the VM_MAYBE_GUARD flag on guard region install
> >   tools/testing/vma: add VMA sticky userland tests
> >   mm: propagate VM_SOFTDIRTY on merge
> >   testing/selftests/mm: add soft-dirty merge self-test
> >
> >  Documentation/filesystems/proc.rst      |   5 +-
> >  fs/proc/task_mmu.c                      |   1 +
> >  include/linux/mm.h                      | 100 +++++++++++++++++
> >  include/trace/events/mmflags.h          |   1 +
> >  mm/khugepaged.c                         |  71 +++++++-----
> >  mm/madvise.c                            |  24 +++--
> >  mm/memory.c                             |  14 +--
> >  mm/mlock.c                              |   2 +-
> >  mm/mprotect.c                           |   2 +-
> >  mm/mseal.c                              |   7 +-
> >  mm/vma.c                                |  81 +++++++-------
> >  mm/vma.h                                | 138 +++++++++++++++++-------
> >  tools/testing/selftests/mm/soft-dirty.c | 127 +++++++++++++++++++++-
> >  tools/testing/vma/vma.c                 |  92 ++++++++++++++--
> >  tools/testing/vma/vma_internal.h        |  49 +++++++++
> >  15 files changed, 579 insertions(+), 135 deletions(-)
> >
> > --
> > 2.53.0