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

[Lorenzo Stoakes <ljs@kernel.org>]

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.
>
> 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