linux-stable.git/tools/testing/vma/include, branch v7.0.4

mm: various small mmap_prepare cleanups

2026-05-07T04:14:15+00:00

[ Upstream commit 3e4bb2706817710d9461394da8b75be79981586b ]

Patch series "mm: expand mmap_prepare functionality and usage", v4.

This series expands the mmap_prepare functionality, which is intended to
replace the deprecated f_op->mmap hook which has been the source of bugs
and security issues for some time.

This series starts with some cleanup of existing mmap_prepare logic, then
adds documentation for the mmap_prepare call to make it easier for
filesystem and driver writers to understand how it works.

It then importantly adds a vm_ops->mapped hook, a key feature that was
missing from mmap_prepare previously - this is invoked when a driver which
specifies mmap_prepare has successfully been mapped but not merged with
another VMA.

mmap_prepare is invoked prior to a merge being attempted, so you cannot
manipulate state such as reference counts as if it were a new mapping.

The vm_ops->mapped hook allows a driver to perform tasks required at this
stage, and provides symmetry against subsequent vm_ops->open,close calls.

The series uses this to correct the afs implementation which wrongly
manipulated reference count at mmap_prepare time.

It then adds an mmap_prepare equivalent of vm_iomap_memory() -
mmap_action_simple_ioremap(), then uses this to update a number of drivers.

It then splits out the mmap_prepare compatibility layer (which allows for
invocation of mmap_prepare hooks in an mmap() hook) in such a way as to
allow for more incremental implementation of mmap_prepare hooks.

It then uses this to extend mmap_prepare usage in drivers.

Finally it adds an mmap_prepare equivalent of vm_map_pages(), which lays
the foundation for future work which will extend mmap_prepare to DMA
coherent mappings.

This patch (of 21):

Rather than passing arbitrary fields, pass a vm_area_desc pointer to mmap
prepare functions to mmap prepare, and an action and vma pointer to mmap
complete in order to put all the action-specific logic in the function
actually doing the work.

Additionally, allow mmap prepare functions to return an error so we can
error out as soon as possible if there is something logically incorrect in
the input.

Update remap_pfn_range_prepare() to properly check the input range for the
CoW case.

Also remove io_remap_pfn_range_complete(), as we can simply set up the
fields correctly in io_remap_pfn_range_prepare() and use
remap_pfn_range_complete() for this.

While we're here, make remap_pfn_range_prepare_vma() a little neater, and
pass mmap_action directly to call_action_complete().

Then, update compat_vma_mmap() to perform its logic directly, as
__compat_vma_map() is not used by anything so we don't need to export it.

Also update compat_vma_mmap() to use vfs_mmap_prepare() rather than
calling the mmap_prepare op directly.

Finally, update the VMA userland tests to reflect the changes.

Link: https://lkml.kernel.org/r/cover.1774045440.git.ljs@kernel.org
Link: https://lkml.kernel.org/r/99f408e4694f44ab12bdc55fe0bd9685d3bd1117.1774045440.git.ljs@kernel.org
Signed-off-by: Lorenzo Stoakes (Oracle) 
Acked-by: Vlastimil Babka (SUSE) 
Cc: Alexander Shishkin 
Cc: Alexandre Torgue 
Cc: Al Viro 
Cc: Arnd Bergmann 
Cc: Bodo Stroesser 
Cc: Christian Brauner 
Cc: Clemens Ladisch 
Cc: David Hildenbrand 
Cc: David Howells 
Cc: Dexuan Cui 
Cc: Greg Kroah-Hartman 
Cc: Haiyang Zhang 
Cc: Jan Kara 
Cc: Jann Horn 
Cc: Jonathan Corbet 
Cc: K. Y. Srinivasan 
Cc: Liam Howlett 
Cc: Long Li 
Cc: Marc Dionne 
Cc: "Martin K. Petersen" 
Cc: Maxime Coquelin 
Cc: Michal Hocko 
Cc: Mike Rapoport 
Cc: Miquel Raynal 
Cc: Pedro Falcato 
Cc: Richard Weinberger 
Cc: Ryan Roberts 
Cc: Suren Baghdasaryan 
Cc: Vignesh Raghavendra 
Cc: Wei Liu 
Signed-off-by: Andrew Morton 
Stable-dep-of: f96e1d5f15b7 ("mm: avoid deadlock when holding rmap on mmap_prepare error")
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

mm: prevent droppable mappings from being locked

2026-05-07T04:13:44+00:00

commit d239462787b072c78eb19fc1f155c3d411256282 upstream.

Droppable mappings must not be lockable.  There is a check for VMAs with
VM_DROPPABLE set in mlock_fixup() along with checks for other types of
unlockable VMAs which ensures this when calling mlock()/mlock2().

For mlockall(MCL_FUTURE), the check for unlockable VMAs is different.  In
apply_mlockall_flags(), if the flags parameter has MCL_FUTURE set, the
current task's mm's default VMA flag field mm->def_flags has VM_LOCKED
applied to it.  VM_LOCKONFAULT is also applied if MCL_ONFAULT is also set.
When these flags are set as default in this manner they are cleared in
__mmap_complete() for new mappings that do not support mlock.  A check for
VM_DROPPABLE in __mmap_complete() is missing resulting in droppable
mappings created with VM_LOCKED set.  To fix this and reduce that chance
of similar bugs in the future, introduce and use vma_supports_mlock().

Link: https://lkml.kernel.org/r/20260310155821.17869-1-anthony.yznaga@oracle.com
Fixes: 9651fcedf7b9 ("mm: add MAP_DROPPABLE for designating always lazily freeable mappings")
Signed-off-by: Anthony Yznaga 
Suggested-by: David Hildenbrand 
Acked-by: David Hildenbrand (Arm) 
Reviewed-by: Pedro Falcato 
Reviewed-by: Lorenzo Stoakes (Oracle) 
Tested-by: Lorenzo Stoakes (Oracle) 
Cc: Jann Horn 
Cc: Jason A. Donenfeld 
Cc: Liam Howlett 
Cc: Michal Hocko 
Cc: Mike Rapoport 
Cc: Shuah Khan 
Cc: Suren Baghdasaryan 
Cc: Vlastimil Babka 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

tools/testing/vma: add VMA userland tests for VMA flag functions

2026-02-12T23:42:59+00:00

Now we have the capability to test the new helpers for the bitmap VMA
flags in userland, do so.

We also update the Makefile such that both VMA (and while we're here)
mm_struct flag sizes can be customised on build.  We default to 128-bit to
enable testing of flags above word size even on 64-bit systems.

We add userland tests to ensure that we do not regress VMA flag behaviour
with the introduction when using bitmap VMA flags, nor accidentally
introduce unexpected results due to for instance higher bit values not
being correctly cleared/set.

As part of this change, make __mk_vma_flags() a custom function so we can
handle specifying invalid VMA bits.  This is purposeful so we can have the
VMA tests work at lower and higher number of VMA flags without having to
duplicate code too much.

Link: https://lkml.kernel.org/r/7fe6afe9c8c61e4d3cfc9a2d50a5d24da8528e68.1769097829.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes 
Reviewed-by: Liam R. Howlett 
Cc: Baolin Wang 
Cc: Barry Song 
Cc: David Hildenbrand 
Cc: Dev Jain 
Cc: Jason Gunthorpe 
Cc: Suren Baghdasaryan 
Cc: Vlastimil Babka 
Cc: Zi Yan 
Cc: Damien Le Moal 
Cc: "Darrick J. Wong" 
Cc: Jarkko Sakkinen 
Cc: Yury Norov 
Cc: Chris Mason 
Cc: Pedro Falcato 
Signed-off-by: Andrew Morton

tools/testing/vma: separate out vma_internal.h into logical headers

2026-02-12T23:42:59+00:00

The vma_internal.h file is becoming entirely unmanageable.  It combines
duplicated kernel implementation logic that needs to be kept in-sync with
the kernel, stubbed out declarations that we simply ignore for testing
purposes and custom logic added to aid testing.

If we separate each of the three things into separate headers it makes
things far more manageable, so do so:

* include/stubs.h  contains the stubbed declarations,
* include/dup.h    contains the duplicated kernel declarations, and
* include/custom.h contains declarations customised for testing.

[lorenzo.stoakes@oracle.com: avoid a duplicate struct define]
  Link: https://lkml.kernel.org/r/1e032732-61c3-485c-9aa7-6a09016fefc1@lucifer.local
Link: https://lkml.kernel.org/r/dd57baf5b5986cb96a167150ac712cbe804b63ee.1769097829.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes 
Reviewed-by: Liam R. Howlett 
Cc: Baolin Wang 
Cc: Barry Song 
Cc: David Hildenbrand 
Cc: Dev Jain 
Cc: Jason Gunthorpe 
Cc: Suren Baghdasaryan 
Cc: Vlastimil Babka 
Cc: Zi Yan 
Cc: Damien Le Moal 
Cc: "Darrick J. Wong" 
Cc: Jarkko Sakkinen 
Cc: Yury Norov 
Cc: Chris Mason 
Cc: Pedro Falcato 
Signed-off-by: Andrew Morton