[PATCH 6.1.y 0/3] mm/ksm: fix userfaultfd protection on 6.1

[Lance Yang <lance.yang@linux.dev>]

Hi Sasha,

Could we take David's two KSM patches first for 6.1.y? Both cherry-pick
cleanly. 6.1 already has FAULT_FLAG_UNSHARE, but KSM still breaks COW with
a fake write fault.

Patch 2 needs patch 1, and patch 3 needs both.

Thanks,
Lance

Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Xu Xin <xu.xin@linux.dev>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Bobby Powers <bobbypowers@gmail.com>
Cc: Brian Geffon <bgeffon@google.com>
Cc: Denis Plotnikov <dplotnikov@virtuozzo.com>
Cc: Doug Gilbert <dgilbert@interlog.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Martin Cracauer <cracauer@cons.org>
Cc: Marty McFadden <mcfadden8@llnl.gov>
Cc: Maya Gokhale <gokhale2@llnl.gov>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Shaohua Li <shli@fb.com>
Cc: James Houghton <jthoughton@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: SJ Park <sj@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Mohammed EL Kadiri <med08elkadiri@gmail.com>
Cc: David Hildenbrand <david@kernel.org>

David Hildenbrand (2):
  mm/ksm: simplify break_ksm() to not rely on VM_FAULT_WRITE
  mm/ksm: fix KSM COW breaking with userfaultfd-wp via
    FAULT_FLAG_UNSHARE

Lance Yang (1):
  mm/ksm: fix userfaultfd protection during merge and unmerge

 mm/ksm.c | 39 +++++++++++++++++++++------------------
 1 file changed, 21 insertions(+), 18 deletions(-)

-- 
2.49.0