linux.git/mm/migrate_device.c, branch v6.9

mm: convert page_try_share_anon_rmap() to folio_try_share_anon_rmap_[pte|pmd]()

2023-12-29T19:58:56+00:00

Let's convert it like we converted all the other rmap functions.  Don't
introduce folio_try_share_anon_rmap_ptes() for now, as we don't have a
user that wants rmap batching in sight.  Pretty easy to add later.

All users are easy to convert -- only ksm.c doesn't use folios yet but
that is left for future work -- so let's just do it in a single shot.

While at it, turn the BUG_ON into a WARN_ON_ONCE.

Note that page_try_share_anon_rmap() so far didn't care about pte/pmd
mappings (no compound parameter).  We're changing that so we can perform
better sanity checks and make the code actually more readable/consistent. 
For example, __folio_rmap_sanity_checks() will make sure that a PMD range
actually falls completely into the folio.

Link: https://lkml.kernel.org/r/20231220224504.646757-39-david@redhat.com
Signed-off-by: David Hildenbrand 
Cc: Hugh Dickins 
Cc: Matthew Wilcox (Oracle) 
Cc: Muchun Song 
Cc: Muchun Song 
Cc: Peter Xu 
Cc: Ryan Roberts 
Cc: Yin Fengwei 
Signed-off-by: Andrew Morton

mm/migrate_device: page_remove_rmap() -> folio_remove_rmap_pte()

2023-12-29T19:58:54+00:00

Let's convert migrate_vma_collect_pmd().  While at it, perform more folio
conversion.

Link: https://lkml.kernel.org/r/20231220224504.646757-30-david@redhat.com
Signed-off-by: David Hildenbrand 
Cc: Hugh Dickins 
Cc: Matthew Wilcox (Oracle) 
Cc: Muchun Song 
Cc: Muchun Song 
Cc: Peter Xu 
Cc: Ryan Roberts 
Cc: Yin Fengwei 
Signed-off-by: Andrew Morton

mm: convert migrate_vma_insert_page() to use a folio

2023-12-29T19:58:26+00:00

Replaces five calls to compound_head() with one.

Link: https://lkml.kernel.org/r/20231211162214.2146080-8-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) 
Reviewed-by: David Hildenbrand 
Reviewed-by: Alistair Popple 
Signed-off-by: Andrew Morton

Merge tag 'x86_shstk_for_6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2023-08-31T19:20:12+00:00

Pull x86 shadow stack support from Dave Hansen:
 "This is the long awaited x86 shadow stack support, part of Intel's
  Control-flow Enforcement Technology (CET).

  CET consists of two related security features: shadow stacks and
  indirect branch tracking. This series implements just the shadow stack
  part of this feature, and just for userspace.

  The main use case for shadow stack is providing protection against
  return oriented programming attacks. It works by maintaining a
  secondary (shadow) stack using a special memory type that has
  protections against modification. When executing a CALL instruction,
  the processor pushes the return address to both the normal stack and
  to the special permission shadow stack. Upon RET, the processor pops
  the shadow stack copy and compares it to the normal stack copy.

  For more information, refer to the links below for the earlier
  versions of this patch set"

Link: https://lore.kernel.org/lkml/20220130211838.8382-1-rick.p.edgecombe@intel.com/
Link: https://lore.kernel.org/lkml/20230613001108.3040476-1-rick.p.edgecombe@intel.com/

* tag 'x86_shstk_for_6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (47 commits)
  x86/shstk: Change order of __user in type
  x86/ibt: Convert IBT selftest to asm
  x86/shstk: Don't retry vm_munmap() on -EINTR
  x86/kbuild: Fix Documentation/ reference
  x86/shstk: Move arch detail comment out of core mm
  x86/shstk: Add ARCH_SHSTK_STATUS
  x86/shstk: Add ARCH_SHSTK_UNLOCK
  x86: Add PTRACE interface for shadow stack
  selftests/x86: Add shadow stack test
  x86/cpufeatures: Enable CET CR4 bit for shadow stack
  x86/shstk: Wire in shadow stack interface
  x86: Expose thread features in /proc/$PID/status
  x86/shstk: Support WRSS for userspace
  x86/shstk: Introduce map_shadow_stack syscall
  x86/shstk: Check that signal frame is shadow stack mem
  x86/shstk: Check that SSP is aligned on sigreturn
  x86/shstk: Handle signals for shadow stack
  x86/shstk: Introduce routines modifying shstk
  x86/shstk: Handle thread shadow stack
  x86/shstk: Add user-mode shadow stack support
  ...

merge mm-hotfixes-stable into mm-stable to pick up depended-upon changes

2023-08-21T21:26:20+00:00

mm: enable page walking API to lock vmas during the walk

2023-08-21T20:07:20+00:00

walk_page_range() and friends often operate under write-locked mmap_lock. 
With introduction of vma locks, the vmas have to be locked as well during
such walks to prevent concurrent page faults in these areas.  Add an
additional member to mm_walk_ops to indicate locking requirements for the
walk.

The change ensures that page walks which prevent concurrent page faults
by write-locking mmap_lock, operate correctly after introduction of
per-vma locks.  With per-vma locks page faults can be handled under vma
lock without taking mmap_lock at all, so write locking mmap_lock would
not stop them.  The change ensures vmas are properly locked during such
walks.

A sample issue this solves is do_mbind() performing queue_pages_range()
to queue pages for migration.  Without this change a concurrent page
can be faulted into the area and be left out of migration.

Link: https://lkml.kernel.org/r/20230804152724.3090321-2-surenb@google.com
Signed-off-by: Suren Baghdasaryan 
Suggested-by: Linus Torvalds 
Suggested-by: Jann Horn 
Cc: David Hildenbrand 
Cc: Davidlohr Bueso 
Cc: Hugh Dickins 
Cc: Johannes Weiner 
Cc: Laurent Dufour 
Cc: Liam Howlett 
Cc: Matthew Wilcox (Oracle) 
Cc: Michal Hocko 
Cc: Michel Lespinasse 
Cc: Peter Xu 
Cc: Vlastimil Babka 
Cc: 
Signed-off-by: Andrew Morton

mmu_notifiers: don't invalidate secondary TLBs as part of mmu_notifier_invalidate_range_end()

2023-08-18T17:12:41+00:00

Secondary TLBs are now invalidated from the architecture specific TLB
invalidation functions.  Therefore there is no need to explicitly notify
or invalidate as part of the range end functions.  This means we can
remove mmu_notifier_invalidate_range_end_only() and some of the
ptep_*_notify() functions.

Link: https://lkml.kernel.org/r/90d749d03cbab256ca0edeb5287069599566d783.1690292440.git-series.apopple@nvidia.com
Signed-off-by: Alistair Popple 
Reviewed-by: Jason Gunthorpe 
Cc: Andrew Donnellan 
Cc: Catalin Marinas 
Cc: Chaitanya Kumar Borah 
Cc: Frederic Barrat 
Cc: Jason Gunthorpe 
Cc: John Hubbard 
Cc: Kevin Tian 
Cc: Michael Ellerman 
Cc: Nicholas Piggin 
Cc: Nicolin Chen 
Cc: Robin Murphy 
Cc: Sean Christopherson 
Cc: SeongJae Park 
Cc: Tvrtko Ursulin 
Cc: Will Deacon 
Cc: Zhi Wang 
Signed-off-by: Andrew Morton

mm/migrate_device: try to handle swapcache pages

2023-08-18T17:12:09+00:00

Migrating file pages and swapcache pages into device memory is not
supported.  Try to get rid of the swap cache, and if successful, go ahead
as with other anonymous pages.

Link: https://lkml.kernel.org/r/20230607172944.11713-1-mpenttil@redhat.com
Signed-off-by: Mika Penttilä 
Reviewed-by: "Huang, Ying" 
Reviewed-by: Alistair Popple 
Cc: John Hubbard 
Cc: Ralph Campbell 
Signed-off-by: Andrew Morton

mm: Make pte_mkwrite() take a VMA

2023-07-11T21:12:15+00:00

The x86 Shadow stack feature includes a new type of memory called shadow
stack. This shadow stack memory has some unusual properties, which requires
some core mm changes to function properly.

One of these unusual properties is that shadow stack memory is writable,
but only in limited ways. These limits are applied via a specific PTE
bit combination. Nevertheless, the memory is writable, and core mm code
will need to apply the writable permissions in the typical paths that
call pte_mkwrite(). Future patches will make pte_mkwrite() take a VMA, so
that the x86 implementation of it can know whether to create regular
writable or shadow stack mappings.

But there are a couple of challenges to this. Modifying the signatures of
each arch pte_mkwrite() implementation would be error prone because some
are generated with macros and would need to be re-implemented. Also, some
pte_mkwrite() callers operate on kernel memory without a VMA.

So this can be done in a three step process. First pte_mkwrite() can be
renamed to pte_mkwrite_novma() in each arch, with a generic pte_mkwrite()
added that just calls pte_mkwrite_novma(). Next callers without a VMA can
be moved to pte_mkwrite_novma(). And lastly, pte_mkwrite() and all callers
can be changed to take/pass a VMA.

Previous work pte_mkwrite() renamed pte_mkwrite_novma() and converted
callers that don't have a VMA were to use pte_mkwrite_novma(). So now
change pte_mkwrite() to take a VMA and change the remaining callers to
pass a VMA. Apply the same changes for pmd_mkwrite().

No functional change.

Suggested-by: David Hildenbrand 
Signed-off-by: Rick Edgecombe 
Signed-off-by: Dave Hansen 
Reviewed-by: Mike Rapoport (IBM) 
Acked-by: David Hildenbrand 
Link: https://lore.kernel.org/all/20230613001108.3040476-4-rick.p.edgecombe%40intel.com

mm: remove references to pagevec

2023-06-23T23:59:30+00:00

Most of these should just refer to the LRU cache rather than the data
structure used to implement the LRU cache.

Link: https://lkml.kernel.org/r/20230621164557.3510324-13-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) 
Signed-off-by: Andrew Morton