mtdchar: replace deprecated mmap hook with mmap_prepare, clean up
Replace the deprecated mmap callback with mmap_prepare.
Commit f5cf8f07423b ("mtd: Disable mtdchar mmap on MMU systems") commented
out the CONFIG_MMU part of this function back in 2012, so after ~14 years
it's probably reasonable to remove this altogether rather than updating
dead code.
Link: https://lkml.kernel.org/r/d036855c21962c58ace0eb24ecd6d973d77424fe.1774045440.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Acked-by: Richard Weinberger <richard@nod.at> Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexandre Torgue <alexandre.torgue@foss.st.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bodo Stroesser <bostroesser@gmail.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Clemens Ladisch <clemens@ladisch.de> Cc: David Hildenbrand <david@kernel.org> Cc: David Howells <dhowells@redhat.com> Cc: Dexuan Cui <decui@microsoft.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Long Li <longli@microsoft.com> Cc: Marc Dionne <marc.dionne@auristor.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Miquel Raynal <miquel.raynal@bootlin.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vignesh Raghavendra <vigneshr@ti.com> Cc: Wei Liu <wei.liu@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Currently drivers use vm_iomap_memory() as a simple helper function for
I/O remapping memory over a range starting at a specified physical address
over a specified length.
In order to utilise this from mmap_prepare, separate out the core logic
into __simple_ioremap_prep(), update vm_iomap_memory() to use it, and add
simple_ioremap_prepare() to do the same with a VMA descriptor object.
We also add MMAP_SIMPLE_IO_REMAP and relevant fields to the struct
mmap_action type to permit this operation also.
We use mmap_action_ioremap() to set up the actual I/O remap operation once
we have checked and figured out the parameters, which makes
simple_ioremap_prepare() easy to implement.
We then add mmap_action_simple_ioremap() to allow drivers to make use of
this mode.
We update the mmap_prepare documentation to describe this mode. Finally,
we update the VMA tests to reflect this change.
Link: https://lkml.kernel.org/r/a08ef1c4542202684da63bb37f459d5dbbeddd91.1774045440.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Reviewed-by: Suren Baghdasaryan <surenb@google.com> Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexandre Torgue <alexandre.torgue@foss.st.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bodo Stroesser <bostroesser@gmail.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Clemens Ladisch <clemens@ladisch.de> Cc: David Hildenbrand <david@kernel.org> Cc: David Howells <dhowells@redhat.com> Cc: Dexuan Cui <decui@microsoft.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Long Li <longli@microsoft.com> Cc: Marc Dionne <marc.dionne@auristor.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Miquel Raynal <miquel.raynal@bootlin.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Richard Weinberger <richard@nod.at> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Vignesh Raghavendra <vigneshr@ti.com> Cc: Wei Liu <wei.liu@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Commit 9d5403b1036c ("fs: convert most other generic_file_*mmap() users to
.mmap_prepare()") updated AFS to use the mmap_prepare callback in favour
of the deprecated mmap callback.
However, it did not account for the fact that mmap_prepare is called
pre-merge, and may then be merged, nor that mmap_prepare can fail to map
due to an out of memory error.
This change was therefore since reverted.
Both of those are cases in which we should not be incrementing a reference
count.
With the newly added vm_ops->mapped callback available, we can simply
defer this operation to that callback which is only invoked once the
mapping is successfully in place (but not yet visible to userspace as the
mmap and VMA write locks are held).
This allows us to once again reimplement the .mmap_prepare implementation
for this file system.
Therefore add afs_mapped() to implement this callback for AFS, and remove
the code doing so in afs_mmap_prepare().
Also update afs_vm_open(), afs_vm_close() and afs_vm_map_pages() to be
consistent in how the vnode is accessed.
Link: https://lkml.kernel.org/r/ad9a94350a9c7d2bdab79fc397ef0f64d3412d71.1774045440.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexandre Torgue <alexandre.torgue@foss.st.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bodo Stroesser <bostroesser@gmail.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Clemens Ladisch <clemens@ladisch.de> Cc: David Hildenbrand <david@kernel.org> Cc: David Howells <dhowells@redhat.com> Cc: Dexuan Cui <decui@microsoft.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Long Li <longli@microsoft.com> Cc: Marc Dionne <marc.dionne@auristor.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Miquel Raynal <miquel.raynal@bootlin.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Richard Weinberger <richard@nod.at> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vignesh Raghavendra <vigneshr@ti.com> Cc: Wei Liu <wei.liu@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Partially reverts commit 9d5403b1036c ("fs: convert most other
generic_file_*mmap() users to .mmap_prepare()").
This is because the .mmap invocation establishes a refcount, but
.mmap_prepare is called at a point where a merge or an allocation failure
might happen after the call, which would leak the refcount increment.
Functionality is being added to permit the use of .mmap_prepare in this
case, but in the interim, we need to fix this.
Link: https://lkml.kernel.org/r/08804c94e39d9102a3a8fbd12385e8aa079ba1d3.1774045440.git.ljs@kernel.org Fixes: 9d5403b1036c ("fs: convert most other generic_file_*mmap() users to .mmap_prepare()") Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexandre Torgue <alexandre.torgue@foss.st.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bodo Stroesser <bostroesser@gmail.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Clemens Ladisch <clemens@ladisch.de> Cc: David Hildenbrand <david@kernel.org> Cc: David Howells <dhowells@redhat.com> Cc: Dexuan Cui <decui@microsoft.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Long Li <longli@microsoft.com> Cc: Marc Dionne <marc.dionne@auristor.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Miquel Raynal <miquel.raynal@bootlin.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Richard Weinberger <richard@nod.at> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vignesh Raghavendra <vigneshr@ti.com> Cc: Vlastimil Babka (SUSE) <vbabka@kernel.org> Cc: Wei Liu <wei.liu@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Previously, when a driver needed to do something like establish a
reference count, it could do so in the mmap hook in the knowledge that the
mapping would succeed.
With the introduction of f_op->mmap_prepare this is no longer the case, as
it is invoked prior to actually establishing the mapping.
mmap_prepare is not appropriate for this kind of thing as it is called
before any merge might take place, and after which an error might occur
meaning resources could be leaked.
To take this into account, introduce a new vm_ops->mapped callback which
is invoked when the VMA is first mapped (though notably - not when it is
merged - which is correct and mirrors existing mmap/open/close behaviour).
We do better that vm_ops->open() here, as this callback can return an
error, at which point the VMA will be unmapped.
Note that vm_ops->mapped() is invoked after any mmap action is complete
(such as I/O remapping).
We intentionally do not expose the VMA at this point, exposing only the
fields that could be used, and an output parameter in case the operation
needs to update the vma->vm_private_data field.
In order to deal with stacked filesystems which invoke inner filesystem's
mmap() invocations, add __compat_vma_mapped() and invoke it on vfs_mmap()
(via compat_vma_mmap()) to ensure that the mapped callback is handled when
an mmap() caller invokes a nested filesystem's mmap_prepare() callback.
Update the mmap_prepare documentation to describe the mapped hook and make
it clear what its intended use is.
The vm_ops->mapped() call is handled by the mmap complete logic to ensure
the same code paths are handled by both the compatibility and VMA layers.
Additionally, update VMA userland test headers to reflect the change.
Link: https://lkml.kernel.org/r/4c5e98297eb0aae9565c564e1c296a112702f144.1774045440.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexandre Torgue <alexandre.torgue@foss.st.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bodo Stroesser <bostroesser@gmail.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Clemens Ladisch <clemens@ladisch.de> Cc: David Hildenbrand <david@kernel.org> Cc: David Howells <dhowells@redhat.com> Cc: Dexuan Cui <decui@microsoft.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Long Li <longli@microsoft.com> Cc: Marc Dionne <marc.dionne@auristor.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Miquel Raynal <miquel.raynal@bootlin.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Richard Weinberger <richard@nod.at> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vignesh Raghavendra <vigneshr@ti.com> Cc: Wei Liu <wei.liu@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm: have mmap_action_complete() handle the rmap lock and unmap
Rather than have the callers handle this both the rmap lock release and
unmapping the VMA on error, handle it within the mmap_action_complete()
logic where it makes sense to, being careful not to unlock twice.
This simplifies the logic and makes it harder to make mistake with this,
while retaining correct behaviour with regard to avoiding deadlocks.
Also replace the call_action_complete() function with a direct invocation
of mmap_action_complete() as the abstraction is no longer required.
Also update the VMA tests to reflect this change.
Link: https://lkml.kernel.org/r/8d1ee8ebd3542d006a47e8382fb80cf5b57ecf10.1774045440.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexandre Torgue <alexandre.torgue@foss.st.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bodo Stroesser <bostroesser@gmail.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Clemens Ladisch <clemens@ladisch.de> Cc: David Hildenbrand <david@kernel.org> Cc: David Howells <dhowells@redhat.com> Cc: Dexuan Cui <decui@microsoft.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Long Li <longli@microsoft.com> Cc: Marc Dionne <marc.dionne@auristor.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Miquel Raynal <miquel.raynal@bootlin.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Richard Weinberger <richard@nod.at> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vignesh Raghavendra <vigneshr@ti.com> Cc: Wei Liu <wei.liu@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
We don't need to reference this field, it's confusing as it duplicates
mmap_action->hide_from_rmap_until_complete, so thread the mmap_action
through to __mmap_new_vma() instead and use the same field consistently.
Link: https://lkml.kernel.org/r/42c3fbb701e361a17193ecda0d2dabcc326288a5.1774045440.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexandre Torgue <alexandre.torgue@foss.st.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bodo Stroesser <bostroesser@gmail.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Clemens Ladisch <clemens@ladisch.de> Cc: David Hildenbrand <david@kernel.org> Cc: David Howells <dhowells@redhat.com> Cc: Dexuan Cui <decui@microsoft.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Long Li <longli@microsoft.com> Cc: Marc Dionne <marc.dionne@auristor.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Miquel Raynal <miquel.raynal@bootlin.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Richard Weinberger <richard@nod.at> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vignesh Raghavendra <vigneshr@ti.com> Cc: Wei Liu <wei.liu@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm: switch the rmap lock held option off in compat layer
In the mmap_prepare compatibility layer, we don't need to hold the rmap
lock, as we are being called from an .mmap handler.
The .mmap_prepare hook, when invoked in the VMA logic, is called prior to
the VMA being instantiated, but the completion hook is called after the VMA
is linked into the maple tree, meaning rmap walkers can reach it.
The mmap hook does not link the VMA into the tree, so this cannot happen.
Therefore it's safe to simply disable this in the mmap_prepare
compatibility layer.
Also update VMA tests code to reflect current compatibility layer state.
[akpm@linux-foundation.org: fix comment typo, per Vlastimil] Link: https://lkml.kernel.org/r/dda74230d26a1fcd79a3efab61fa4101dd1cac64.1774045440.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexandre Torgue <alexandre.torgue@foss.st.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bodo Stroesser <bostroesser@gmail.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Clemens Ladisch <clemens@ladisch.de> Cc: David Hildenbrand <david@kernel.org> Cc: David Howells <dhowells@redhat.com> Cc: Dexuan Cui <decui@microsoft.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Long Li <longli@microsoft.com> Cc: Marc Dionne <marc.dionne@auristor.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Miquel Raynal <miquel.raynal@bootlin.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Richard Weinberger <richard@nod.at> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vignesh Raghavendra <vigneshr@ti.com> Cc: Wei Liu <wei.liu@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm: avoid deadlock when holding rmap on mmap_prepare error
Commit ac0a3fc9c07d ("mm: add ability to take further action in
vm_area_desc") added the ability for drivers to instruct mm to take actions
after the .mmap_prepare callback is complete.
To make life simpler and safer, this is done before the VMA/mmap write lock
is dropped but when the VMA is completely established.
So on error, we simply munmap() the VMA.
As part of this implementation, unfortunately a horrible hack had to be
implemented to support some questionable behaviour hugetlb relies upon -
that is that the file rmap lock is held until the operation is complete.
The implementation, for convenience, did this in mmap_action_finish() so
both the VMA and mmap_prepare compatibility layer paths would have this
correctly handled.
However, it turns out there is a mistake here - the rmap lock cannot be
held on munmap, as free_pgtables() -> unlink_file_vma_batch_add() ->
unlink_file_vma_batch_process() takes the file rmap lock.
We therefore currently have a deadlock issue that might arise.
Resolve this by leaving it to callers to handle the unmap.
The compatibility layer does not support this rmap behaviour, so we simply
have it unmap on error after calling mmap_action_complete().
In the VMA implementation, we only perform the unmap after the rmap lock is
dropped.
This resolves the issue by ensuring the rmap lock is always dropped when
the unmap occurs.
Link: https://lkml.kernel.org/r/d44248be9da68258b07c2c59d4e73485ee0ca943.1774045440.git.ljs@kernel.org Fixes: ac0a3fc9c07d ("mm: add ability to take further action in vm_area_desc") Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexandre Torgue <alexandre.torgue@foss.st.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bodo Stroesser <bostroesser@gmail.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Clemens Ladisch <clemens@ladisch.de> Cc: David Hildenbrand <david@kernel.org> Cc: David Howells <dhowells@redhat.com> Cc: Dexuan Cui <decui@microsoft.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Long Li <longli@microsoft.com> Cc: Marc Dionne <marc.dionne@auristor.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Miquel Raynal <miquel.raynal@bootlin.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Richard Weinberger <richard@nod.at> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vignesh Raghavendra <vigneshr@ti.com> Cc: Vlastimil Babka (SUSE) <vbabka@kernel.org> Cc: Wei Liu <wei.liu@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm: add documentation for the mmap_prepare file operation callback
This documentation makes it easier for a driver/file system implementer to
correctly use this callback.
It covers the fundamentals, whilst intentionally leaving the less lovely
possible actions one might take undocumented (for instance - the
success_hook, error_hook fields in mmap_action).
The document also covers the new VMA flags implementation which is the
only one which will work correctly with mmap_prepare.
Link: https://lkml.kernel.org/r/3aebf918c213fa2aecf00a31a444119b5bdd7801.1774045440.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexandre Torgue <alexandre.torgue@foss.st.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bodo Stroesser <bostroesser@gmail.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Clemens Ladisch <clemens@ladisch.de> Cc: David Hildenbrand <david@kernel.org> Cc: David Howells <dhowells@redhat.com> Cc: Dexuan Cui <decui@microsoft.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Long Li <longli@microsoft.com> Cc: Marc Dionne <marc.dionne@auristor.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Miquel Raynal <miquel.raynal@bootlin.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Richard Weinberger <richard@nod.at> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vignesh Raghavendra <vigneshr@ti.com> Cc: Wei Liu <wei.liu@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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) <ljs@kernel.org> Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexandre Torgue <alexandre.torgue@foss.st.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bodo Stroesser <bostroesser@gmail.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Clemens Ladisch <clemens@ladisch.de> Cc: David Hildenbrand <david@kernel.org> Cc: David Howells <dhowells@redhat.com> Cc: Dexuan Cui <decui@microsoft.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Long Li <longli@microsoft.com> Cc: Marc Dionne <marc.dionne@auristor.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Miquel Raynal <miquel.raynal@bootlin.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Richard Weinberger <richard@nod.at> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vignesh Raghavendra <vigneshr@ti.com> Cc: Wei Liu <wei.liu@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
We have implemented flag mask comparisons of the form:
if ((vm_flags & (VM_FOO|VM_BAR|VM_BAZ) == VM_FOO) { ... }
Like-for-like in the code using a bitwise-and mask via vma_flags_and() and
using vma_flags_same() to ensure the final result equals only the required
flag value.
This is fine but confusing, make things clearer by instead explicitly
excluding undesired flags and including the desired one via tests of the
form:
if (vma_flags_test(&flags, VMA_FOO_BIT) &&
!vma_flags_test_any(&flags, VMA_BAR_BIT, VMA_BAZ_BIT)) { ... }
Which makes it easier to understand what is going on.
No functional change intended.
Link: https://lkml.kernel.org/r/d395c5dd837a9864f5efcec42175910afbe3ce73.1774034900.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Suggested-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Kees Cook <kees@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Ondrej Mosnacek <omosnace@redhat.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Moore <paul@paul-moore.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Stephen Smalley <stephen.smalley.work@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Will Deacon <will@kernel.org> Cc: xu xin <xu.xin16@zte.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm/vma: convert __mmap_region() to use vma_flags_t
Update the mmap() implementation logic implemented in __mmap_region() and
functions invoked by it. The mmap_region() function converts its input
vm_flags_t parameter to a vma_flags_t value which it then passes to
__mmap_region() which uses the vma_flags_t value consistently from then
on.
As part of the change, we convert map_deny_write_exec() to using
vma_flags_t (it was incorrectly using unsigned long before), and place it
in vma.h, as it is only used internal to mm.
With this change, we eliminate the legacy is_shared_maywrite_vm_flags()
helper function which is now no longer required.
We are also able to update the MMAP_STATE() and VMG_MMAP_STATE() macros to
use the vma_flags_t value.
Finally, we update the VMA tests to reflect the change.
Link: https://lkml.kernel.org/r/1fc33a404c962f02da778da100387cc19bd62153.1774034900.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Kees Cook <kees@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Ondrej Mosnacek <omosnace@redhat.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Moore <paul@paul-moore.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Stephen Smalley <stephen.smalley.work@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Will Deacon <will@kernel.org> Cc: xu xin <xu.xin16@zte.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm/vma: convert vma_modify_flags[_uffd]() to use vma_flags_t
Update the vma_modify_flags() and vma_modify_flags_uffd() functions to
accept a vma_flags_t parameter rather than a vm_flags_t one, and propagate
the changes as needed to implement this change.
Also add vma_flags_reset_once() in replacement of vm_flags_reset_once(). We
still need to be careful here because we need to avoid tearing, so maintain
the assumption that the first system word set of flags are the only ones
that require protection from tearing, and retain this functionality.
We can copy the remainder of VMA flags above 64 bits normally. But
hopefully by the time that happens, we will have replaced the logic that
requires these WRITE_ONCE()'s with something else.
We also replace instances of vm_flags_reset() with a simple write of VMA
flags. We are no longer perform a number of checks, most notable of all the
VMA flags asserts becase:
1. We might be operating on a VMA that is not yet added to the tree.
2. We might be operating on a VMA that is now detached.
3. Really in all but core code, you should be using vma_desc_xxx().
4. Other VMA fields are manipulated with no such checks.
5. It'd be egregious to have to add variants of flag functions just to
account for cases such as the above, especially when we don't do so for
other VMA fields. Drivers are the problematic cases and why it was
especially important (and also for debug as VMA locks were introduced),
the mmap_prepare work is solving this generally.
Additionally, we can fairly safely assume by this point the soft dirty
flags are being set correctly, so it's reasonable to drop this also.
Finally, update the VMA tests to reflect this.
Link: https://lkml.kernel.org/r/51afbb2b8c3681003cc7926647e37335d793836e.1774034900.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Kees Cook <kees@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Ondrej Mosnacek <omosnace@redhat.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Moore <paul@paul-moore.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Stephen Smalley <stephen.smalley.work@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Will Deacon <will@kernel.org> Cc: xu xin <xu.xin16@zte.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm/vma: convert as much as we can in mm/vma.c to vma_flags_t
Now we have established a good foundation for vm_flags_t to vma_flags_t
changes, update mm/vma.c to utilise vma_flags_t wherever possible.
We are able to convert VM_STARTGAP_FLAGS entirely as this is only used in
mm/vma.c, and to account for the fact we can't use VM_NONE to make life
easier, place the definition of this within existing #ifdef's to be
cleaner.
Generally the remaining changes are mechanical.
Also update the VMA tests to reflect the changes.
Link: https://lkml.kernel.org/r/5fdeaf8af9a12c2a5d68497495f52fa627d05a5b.1774034900.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Kees Cook <kees@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Ondrej Mosnacek <omosnace@redhat.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Moore <paul@paul-moore.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Stephen Smalley <stephen.smalley.work@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Will Deacon <will@kernel.org> Cc: xu xin <xu.xin16@zte.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Introduce a helper function and helper macro to easily clear a VMA's flags
using the new vma_flags_t vma->flags field:
* vma_clear_flags_mask() - Clears all of the flags in a specified mask in
the VMA's flags field.
* vma_clear_flags() - Clears all of the specified individual VMA flag bits
in a VMA's flags field.
Also update the VMA tests to reflect the change.
Link: https://lkml.kernel.org/r/9bd15da35c2c90e7441265adf01b5c2d3b5c6d41.1774034900.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Kees Cook <kees@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Ondrej Mosnacek <omosnace@redhat.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Moore <paul@paul-moore.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Stephen Smalley <stephen.smalley.work@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Will Deacon <will@kernel.org> Cc: xu xin <xu.xin16@zte.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In order to be able to do this, we need to change VM_DATA_DEFAULT_FLAGS
and friends and update the architecture-specific definitions also.
We then have to update some KSM logic to handle VMA flags, and introduce
VMA_STACK_FLAGS to define the vma_flags_t equivalent of VM_STACK_FLAGS.
We also introduce two helper functions for use during the time we are
converting legacy flags to vma_flags_t values - vma_flags_to_legacy() and
legacy_to_vma_flags().
This enables us to iteratively make changes to break these changes up into
separate parts.
We use these explicitly here to keep VM_STACK_FLAGS around for certain
users which need to maintain the legacy vm_flags_t values for the time
being.
We are no longer able to rely on the simple VM_xxx being set to zero if
the feature is not enabled, so in the case of VM_DROPPABLE we introduce
VMA_DROPPABLE as the vma_flags_t equivalent, which is set to
EMPTY_VMA_FLAGS if the droppable flag is not available.
While we're here, we make the description of do_brk_flags() into a kdoc
comment, as it almost was already.
We use vma_flags_to_legacy() to not need to update the vm_get_page_prot()
logic as this time.
Note that in create_init_stack_vma() we have to replace the BUILD_BUG_ON()
with a VM_WARN_ON_ONCE() as the tested values are no longer build time
available.
We also update mprotect_fixup() to use VMA flags where possible, though we
have to live with a little duplication between vm_flags_t and vma_flags_t
values for the time being until further conversions are made.
While we're here, update VM_SPECIAL to be defined in terms of
VMA_SPECIAL_FLAGS now we have vma_flags_to_legacy().
Finally, we update the VMA tests to reflect these changes.
Link: https://lkml.kernel.org/r/d02e3e45d9a33d7904b149f5604904089fd640ae.1774034900.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Acked-by: Paul Moore <paul@paul-moore.com> [SELinux] Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Kees Cook <kees@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Ondrej Mosnacek <omosnace@redhat.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Stephen Smalley <stephen.smalley.work@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Will Deacon <will@kernel.org> Cc: xu xin <xu.xin16@zte.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
tools/testing/vma: test vma_flags_count,vma[_flags]_test_single_mask
Update the VMA tests to assert that vma_flags_count() behaves as expected,
as well as vma_flags_test_single_mask() and vma_test_single_mask().
For the test functions we can simply update the existing vma_test(), et
al. test to also test the single_mask variants.
We also add some explicit testing of an empty VMA flag to this test to
ensure this is handled properly.
In order to test vma_flags_count() we simply take an existing set of flags
and gradually remove flags ensuring the count remains as expected
throughout.
We also update the vma[_flags]_test_all() tests to make clear the
semantics that we expect vma[_flags]_test_all(..., EMPTY_VMA_FLAGS) to
return true, as trivially, all flags of none are always set in VMA flags.
Link: https://lkml.kernel.org/r/4af95d559cd2af0ba3388de1e1386b9f94c0e009.1774034900.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Kees Cook <kees@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Ondrej Mosnacek <omosnace@redhat.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Moore <paul@paul-moore.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Stephen Smalley <stephen.smalley.work@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Vlastimil Babka (SUSE) <vbabka@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Will Deacon <will@kernel.org> Cc: xu xin <xu.xin16@zte.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm: introduce vma_flags_count() and vma[_flags]_test_single_mask()
vma_flags_count() determines how many bits are set in VMA flags, using
bitmap_weight().
vma_flags_test_single_mask() determines if a vma_flags_t set of flags
contains a single flag specified as another vma_flags_t value, or if the
sought flag mask is empty, it is defined to return false.
This is useful when we want to declare a VMA flag as optionally a single
flag in a mask or empty depending on kernel configuration.
This allows us to have VM_NONE-like semantics when checking whether the
flag is set.
In a subsequent patch, we introduce the use of VMA_DROPPABLE of type
vma_flags_t using precisely these semantics.
It would be actively confusing to use vma_flags_test_any_single_mask() for
this (and vma_flags_test_all_mask() is not correct to use here, as it
trivially returns true when tested against an empty vma flags mask).
We introduce vma_flags_count() to be able to assert that the compared flag
mask is singular or empty, checked when CONFIG_DEBUG_VM is enabled.
Also update the VMA tests as part of this change.
Link: https://lkml.kernel.org/r/cd778dd02b9f2a01eb54d25a49dea8ec2ddf7753.1774034900.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Kees Cook <kees@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Ondrej Mosnacek <omosnace@redhat.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Moore <paul@paul-moore.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Stephen Smalley <stephen.smalley.work@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Will Deacon <will@kernel.org> Cc: xu xin <xu.xin16@zte.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
tools/testing/vma: update VMA flag tests to test vma_test[_any_mask]()
Update the existing test logic to assert that vma_test(), vma_test_any()
and vma_test_any_mask() (implicitly tested via vma_test_any()) are
functioning correctly.
We already have tests for other variants like this, so it's simply a
matter of expanding those tests to also include tests for the VMA-specific
helpers.
Link: https://lkml.kernel.org/r/dea3e97c6c3dd86f1a3f1a0703241b03f6e3a33f.1774034900.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Kees Cook <kees@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Ondrej Mosnacek <omosnace@redhat.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Moore <paul@paul-moore.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Stephen Smalley <stephen.smalley.work@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Vlastimil Babka (SUSE) <vbabka@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Will Deacon <will@kernel.org> Cc: xu xin <xu.xin16@zte.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm/vma: introduce vma_test[_any[_mask]](), and make inlining consistent
Introduce helper functions and macros to make it convenient to test flags
and flag masks for VMAs, specifically:
* vma_test() - determine if a single VMA flag is set in a VMA.
* vma_test_any_mask() - determine if any flags in a vma_flags_t value are
set in a VMA.
* vma_test_any() - Helper macro to test if any of specific flags are set.
Also, there are a mix of 'inline's and '__always_inline's in VMA helper
function declarations, update to consistently use __always_inline.
Finally, update the VMA tests to reflect the changes.
Link: https://lkml.kernel.org/r/be1d71f08307d747a82232cbd8664a88c0f41419.1774034900.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Kees Cook <kees@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Ondrej Mosnacek <omosnace@redhat.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Moore <paul@paul-moore.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Stephen Smalley <stephen.smalley.work@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Will Deacon <will@kernel.org> Cc: xu xin <xu.xin16@zte.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
While we are still converting VMA flags from vma_flags_t to vm_flags_t,
introduce helpers to convert between the two to allow for iterative
development without having to 'change the world' in a single commit'.
Also update VMA flags tests to reflect the change.
Finally, refresh vma_flags_overwrite_word(),
vma_flag_overwrite_word_once(), vma_flags_set_word() and
vma_flags_clear_word() in the VMA tests to reflect current kernel
implementations - this should make no functional difference, but keeps the
logic consistent between the two.
Link: https://lkml.kernel.org/r/d3569470dbb3ae79134ca7c3eb3fc4df7086e874.1774034900.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Kees Cook <kees@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Ondrej Mosnacek <omosnace@redhat.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Moore <paul@paul-moore.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Stephen Smalley <stephen.smalley.work@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Will Deacon <will@kernel.org> Cc: xu xin <xu.xin16@zte.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Add helpers to determine if two sets of VMA flags are precisely the same,
that is - that every flag set one is set in another, and neither contain
any flags not set in the other.
We also introduce vma_flags_same_pair() for cases where we want to compare
two sets of VMA flags which are both non-const values.
Also update the VMA tests to reflect the change, we already implicitly
test that this functions correctly having used it for testing purposes
previously.
Link: https://lkml.kernel.org/r/4f764bf619e77205837c7c819b62139ef6337ca3.1774034900.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Kees Cook <kees@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Ondrej Mosnacek <omosnace@redhat.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Moore <paul@paul-moore.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Stephen Smalley <stephen.smalley.work@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Will Deacon <will@kernel.org> Cc: xu xin <xu.xin16@zte.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm: unexport vm_brk_flags() and eliminate vm_flags parameter
This function is only used by elf_load(), and that is a static function
that doesn't need an exported symbol to invoke an internal function, so
un-EXPORT_SYMBOLS() it.
Also, the vm_flags parameter is unnecessary, as we only ever set VM_EXEC,
so simply make this parameter a boolean.
While we're here, clean up the mm.h definitions for the various vm_xxx()
helpers so we actually specify parameter names and elide the redundant
extern's.
Link: https://lkml.kernel.org/r/7bada48ddf3f9dbd3e6c4fc50ec2f4de97706f52.1774034900.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Kees Cook <kees@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Ondrej Mosnacek <omosnace@redhat.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Moore <paul@paul-moore.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Stephen Smalley <stephen.smalley.work@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Will Deacon <will@kernel.org> Cc: xu xin <xu.xin16@zte.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In order to be able to efficiently combine VMA flag masks with additional
VMA flag bits we need to extend the concept introduced in mk_vma_flags()
and __mk_vma_flags() by allowing the specification of a VMA flag mask to
append VMA flag bits to.
Update __mk_vma_flags() to allow for this and update mk_vma_flags()
accordingly, and also provide append_vma_flags() to allow for the caller
to specify which VMA flags mask to append to.
Finally, update the VMA flags tests to reflect the change.
Link: https://lkml.kernel.org/r/9f928cd4688270002f2c0c3777fcc9b49cc7a8ea.1774034900.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Kees Cook <kees@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Ondrej Mosnacek <omosnace@redhat.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Moore <paul@paul-moore.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Stephen Smalley <stephen.smalley.work@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Will Deacon <will@kernel.org> Cc: xu xin <xu.xin16@zte.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The VMA tests are incorrectly referencing NUM_VMA_FLAGS, which doesn't
exist, rather they should reference NUM_VMA_FLAG_BITS.
Additionally, remove the custom-written implementation of __mk_vma_flags()
as this means we are not testing the code as present in the kernel, rather
add the actual __mk_vma_flags() to dup.h and add #ifdef's to handle
declarations differently depending on NUM_VMA_FLAG_BITS.
Link: https://lkml.kernel.org/r/b19c63af3d5efdfe712bf5d5f89368a5360a60f7.1774034900.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Kees Cook <kees@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Ondrej Mosnacek <omosnace@redhat.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Moore <paul@paul-moore.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Stephen Smalley <stephen.smalley.work@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Vlastimil Babka (SUSE) <vbabka@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Will Deacon <will@kernel.org> Cc: xu xin <xu.xin16@zte.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
tools/testing/vma: convert bulk of test code to vma_flags_t
Convert the test code to utilise vma_flags_t as opposed to the deprecate
vm_flags_t as much as possible.
As part of this change, add VMA_STICKY_FLAGS and VMA_SPECIAL_FLAGS as
early versions of what these defines will look like in the kernel logic
once this logic is implemented.
Link: https://lkml.kernel.org/r/df90efe29300bd899989f695be4ae3adc901a828.1774034900.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Kees Cook <kees@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Ondrej Mosnacek <omosnace@redhat.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Moore <paul@paul-moore.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Stephen Smalley <stephen.smalley.work@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Vlastimil Babka (SUSE) <vbabka@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Will Deacon <will@kernel.org> Cc: xu xin <xu.xin16@zte.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In order to utilise the new vma_flags_t type, we currently place it in
union with legacy vm_flags fields of type vm_flags_t to make the
transition smoother.
Add vma_flags_t union entries for mm->def_flags and vmg->vm_flags -
mm->def_vma_flags and vmg->vma_flags respectively.
Once the conversion is complete, these will be replaced with vma_flags_t
entries alone.
Also update the VMA tests to reflect the change.
Link: https://lkml.kernel.org/r/d507d542c089ba132e9da53f2ff7f80ca117c3b4.1774034900.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Kees Cook <kees@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Ondrej Mosnacek <omosnace@redhat.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Moore <paul@paul-moore.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Stephen Smalley <stephen.smalley.work@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Will Deacon <will@kernel.org> Cc: xu xin <xu.xin16@zte.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In additional to the added tests, in order to make testing easier, add
vma_flags_same_mask() and vma_flags_same() for testing only. If/when
these are required in kernel code, they can be moved over.
Also add ASSERT_FLAGS_[NOT_]SAME[_MASK](), ASSERT_FLAGS_[NON]EMPTY() test
helpers to make asserting flag state easier and more convenient.
Link: https://lkml.kernel.org/r/471ce7ceb1d32e5fc9c0660966b9eacdf899b4d1.1774034900.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Kees Cook <kees@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Ondrej Mosnacek <omosnace@redhat.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Moore <paul@paul-moore.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Stephen Smalley <stephen.smalley.work@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Vlastimil Babka (SUSE) <vbabka@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Will Deacon <will@kernel.org> Cc: xu xin <xu.xin16@zte.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "mm/vma: convert vm_flags_t to vma_flags_t in vma code", v4.
This series converts a lot of the existing use of the legacy vm_flags_t
data type to the new vma_flags_t type which replaces it.
In order to do so it adds a number of additional helpers:
* vma_flags_empty() - Determines whether a vma_flags_t value has no bits
set.
* vma_flags_and() - Performs a bitwise AND between two vma_flags_t values.
* vma_flags_diff_pair() - Determines which flags are not shared between a
pair of VMA flags (typically non-constant values)
* append_vma_flags() - Similar to mk_vma_flags(), but allows a vma_flags_t
value to be specified (typically a constant value) which will be copied
and appended to to create a new vma_flags_t value, with additional flags
specified to append to it.
* vma_flags_same() - Determines if a vma_flags_t value is exactly equal to
a set of VMA flags.
* vma_flags_same_mask() - Determines if a vma_flags_t value is eactly equal
to another vma_flags_t value (typically constant).
* vma_flags_same_pair() - Determines if a pair of vma_flags_t values are
exactly equal to one another (typically both non-constant).
* vma_flags_to_legacy() - Converts a vma_flags_t value to a vm_flags_t
value, used to enable more iterative introduction of the use of
vma_flags_t.
* legacy_to_vma_flags() - Converts a vm_flags_t value to a vma_flags-t
value, for the same purpose.
* vma_flags_test_single_mask() - Tests whether a vma_flags_t value contain
the single flag specified in an input vma_flags_t flag mask, or if that
flag mask is empty, is defined to return false. Useful for
config-predicated VMA flag mask defines.
* vma_test() - Tests whether a VMA's flags contain a specific singular VMA
flag.
* vma_test_any() - Tests whether a VMA's flags contain any of a set of VMA
flags.
* vma_test_any_mask() - Tests whether a VMA's flags contain any of the
flags specified in another, typically constant, vma_flags_t value.
* vma_test_single_mask() - Tests whether a VMA's flags contain the single
flag specified in an input vma_flags_t flag mask, or if that flag mask is
empty, is defined to return false. Useful for config-predicated VMA flag
mask defines.
* vma_clear_flags() - Clears a specific set of VMA flags from a vma_flags_t
value.
* vma_clear_flags_mask() - Clears those flag set in a vma_flags_t value
(typically constant) from a (typically not constant) vma_flags_t value.
The series mostly focuses on the the VMA specific code, especially that
contained in mm/vma.c and mm/vma.h.
It updates both brk() and mmap() logic to utils vma_flags_t values as much
as is practiaclly possible at this point, changing surrounding logic to be
able to do so.
It also updates the vma_modify_xxx() functions where they interact with VMA
flags directly to use vm_flags_t values where possible.
There is extensive testing added in the VMA userland tests to assert that
all of these new VMA flag functions work correctly.
This patch (of 25):
Firstly, add the ability to determine if VMA flags are empty, that is no
flags are set in a vma_flags_t value.
Next, add the ability to obtain the equivalent of the bitwise and of two
vma_flags_t values, via vma_flags_and_mask().
Next, add the ability to obtain the difference between two sets of VMA
flags, that is the equivalent to the exclusive bitwise OR of the two sets
of flags, via vma_flags_diff_pair().
vma_flags_xxx_mask() typically operates on a pointer to a vma_flags_t
value, which is assumed to be an lvalue of some kind (such as a field in a
struct or a stack variable) and an rvalue of some kind (typically a
constant set of VMA flags obtained e.g. via mk_vma_flags() or
equivalent).
However vma_flags_diff_pair() is intended to operate on two lvalues, so
use the _pair() suffix to make this clear.
Finally, update VMA userland tests to add these helpers.
We also port bitmap_xor() and __bitmap_xor() to the tools/ headers and
source to allow the tests to work with vma_flags_diff_pair().
Link: https://lkml.kernel.org/r/cover.1774034900.git.ljs@kernel.org Link: https://lkml.kernel.org/r/53ab55b7da91425775e42c03177498ad6de88ef4.1774034900.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Kees Cook <kees@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Ondrej Mosnacek <omosnace@redhat.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Moore <paul@paul-moore.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Stephen Smalley <stephen.smalley.work@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Will Deacon <will@kernel.org> Cc: xu xin <xu.xin16@zte.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Previously we stored the end of the current VMA in curr_end, and then upon
iterating to the next VMA updated curr_start to curr_end to advance to the
next VMA.
However, this doesn't take into account the fact that a VMA might be
updated due to a merge by vma_modify_flags(), which can result in curr_end
being stale and thus, upon setting curr_start to curr_end, ending up with
an incorrect curr_start on the next iteration.
Resolve the issue by setting curr_end to vma->vm_end unconditionally to
ensure this value remains updated should this occur.
While we're here, eliminate this entire class of bug by simply setting
const curr_[start/end] to be clamped to the input range and VMAs, which
also happens to simplify the logic.
Link: https://lkml.kernel.org/r/20260327173104.322405-1-ljs@kernel.org Fixes: 6c2da14ae1e0 ("mm/mseal: rework mseal apply logic") Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Reported-by: Antonius <antonius@bluedragonsec.com> Closes: https://lore.kernel.org/linux-mm/CAK8a0jwWGj9-SgFk0yKFh7i8jMkwKm5b0ao9=kmXWjO54veX2g@mail.gmail.com/ Suggested-by: David Hildenbrand (ARM) <david@kernel.org> Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Reviewed-by: Pedro Falcato <pfalcato@suse.de> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Jann Horn <jannh@google.com> Cc: Jeff Xu <jeffxu@chromium.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Max Boone [Wed, 25 Mar 2026 09:59:16 +0000 (10:59 +0100)]
mm/pagewalk: fix race between concurrent split and refault
The splitting of a PUD entry in walk_pud_range() can race with a
concurrent thread refaulting the PUD leaf entry causing it to try walking
a PMD range that has disappeared.
An example and reproduction of this is to try reading numa_maps of a
process while VFIO-PCI is setting up DMA (specifically the
vfio_pin_pages_remote call) on a large BAR for that process.
Fix this by validating the PUD entry in walk_pmd_range() using a stable
snapshot (pudp_get()). If the PUD is not present or is a leaf, retry the
walk via ACTION_AGAIN instead of descending further. This mirrors the
retry logic in walk_pte_range(), which lets walk_pmd_range() retry if the
PTE is not being got by pte_offset_map_lock().
Link: https://lkml.kernel.org/r/20260325-pagewalk-check-pmd-refault-v2-1-707bff33bc60@akamai.com Fixes: f9e54c3a2f5b ("vfio/pci: implement huge_fault support") Co-developed-by: David Hildenbrand (Arm) <david@kernel.org> Signed-off-by: David Hildenbrand (Arm) <david@kernel.org> Signed-off-by: Max Boone <mboone@akamai.com> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm/memory: fix PMD/PUD checks in follow_pfnmap_start()
follow_pfnmap_start() suffers from two problems:
(1) We are not re-fetching the pmd/pud after taking the PTL
Therefore, we are not properly stabilizing what the lock actually
protects. If there is concurrent zapping, we would indicate to the
caller that we found an entry, however, that entry might already have
been invalidated, or contain a different PFN after taking the lock.
Properly use pmdp_get() / pudp_get() after taking the lock.
(2) pmd_leaf() / pud_leaf() are not well defined on non-present entries
pmd_leaf()/pud_leaf() could wrongly trigger on non-present entries.
There is no real guarantee that pmd_leaf()/pud_leaf() returns something
reasonable on non-present entries. Most architectures indeed either
perform a present check or make it work by smart use of flags.
However, for example loongarch checks the _PAGE_HUGE flag in pmd_leaf(),
and always sets the _PAGE_HUGE flag in __swp_entry_to_pmd(). Whereby
pmd_trans_huge() explicitly checks pmd_present(), pmd_leaf() does not do
that.
Let's check pmd_present()/pud_present() before assuming "the is a present
PMD leaf" when spotting pmd_leaf()/pud_leaf(), like other page table
handling code that traverses user page tables does.
Given that non-present PMD entries are likely rare in VM_IO|VM_PFNMAP, (1)
is likely more relevant than (2). It is questionable how often (1) would
actually trigger, but let's CC stable to be sure.
This was found by code inspection.
Link: https://lkml.kernel.org/r/20260323-follow_pfnmap_fix-v1-1-5b0ec10872b3@kernel.org Fixes: 6da8e9634bb7 ("mm: new follow_pfnmap API") Signed-off-by: David Hildenbrand (Arm) <david@kernel.org> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Peter Xu <peterx@redhat.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Josh Law [Sat, 21 Mar 2026 17:54:26 +0000 (10:54 -0700)]
mm/damon/sysfs: check contexts->nr in repeat_call_fn
damon_sysfs_repeat_call_fn() calls damon_sysfs_upd_tuned_intervals(),
damon_sysfs_upd_schemes_stats(), and
damon_sysfs_upd_schemes_effective_quotas() without checking contexts->nr.
If nr_contexts is set to 0 via sysfs while DAMON is running, these
functions dereference contexts_arr[0] and cause a NULL pointer
dereference. Add the missing check.
For example, the issue can be reproduced using DAMON sysfs interface and
DAMON user-space tool (damo) [1] like below.
Josh Law [Sat, 21 Mar 2026 17:54:25 +0000 (10:54 -0700)]
mm/damon/sysfs: check contexts->nr before accessing contexts_arr[0]
Multiple sysfs command paths dereference contexts_arr[0] without first
verifying that kdamond->contexts->nr == 1. A user can set nr_contexts to
0 via sysfs while DAMON is running, causing NULL pointer dereferences.
In more detail, the issue can be triggered by privileged users like
below.
First, start DAMON and make contexts directory empty
(kdamond->contexts->nr == 0).
Then, each of below commands will cause the NULL pointer dereference.
# echo update_schemes_stats > state
# echo update_schemes_tried_regions > state
# echo update_schemes_tried_bytes > state
# echo update_schemes_effective_quotas > state
# echo update_tuned_intervals > state
Guard all commands (except OFF) at the entry point of
damon_sysfs_handle_cmd().
Link: https://lkml.kernel.org/r/20260321175427.86000-3-sj@kernel.org Fixes: 0ac32b8affb5 ("mm/damon/sysfs: support DAMOS stats") Signed-off-by: Josh Law <objecting@objecting.org> Reviewed-by: SeongJae Park <sj@kernel.org> Signed-off-by: SeongJae Park <sj@kernel.org> Cc: <stable@vger.kernel.org> [5.18+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Josh Law [Sat, 21 Mar 2026 17:54:24 +0000 (10:54 -0700)]
mm/damon/sysfs: fix param_ctx leak on damon_sysfs_new_test_ctx() failure
Patch series "mm/damon/sysfs: fix memory leak and NULL dereference
issues", v4.
DAMON_SYSFS can leak memory under allocation failure, and do NULL pointer
dereference when a privileged user make wrong sequences of control. Fix
those.
This patch (of 3):
When damon_sysfs_new_test_ctx() fails in damon_sysfs_commit_input(),
param_ctx is leaked because the early return skips the cleanup at the out
label. Destroy param_ctx before returning.
Alexandre Ghiti [Fri, 20 Mar 2026 05:05:59 +0000 (06:05 +0100)]
mm/swap: fix swap cache memcg accounting
The swap readahead path was recently refactored and while doing this, the
order between the charging of the folio in the memcg and the addition of
the folio in the swap cache was inverted.
Since the accounting of the folio is done while adding the folio to the
swap cache and the folio is not charged in the memcg yet, the accounting
is then done at the node level, which is wrong.
Fix this by charging the folio in the memcg before adding it to the swap cache.
Link: https://lkml.kernel.org/r/20260320050601.1833108-1-alex@ghiti.fr Fixes: 2732acda82c9 ("mm, swap: use swap cache as the swap in synchronize layer") Signed-off-by: Alexandre Ghiti <alex@ghiti.fr> Acked-by: Kairui Song <kasong@tencent.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Nhat Pham <nphamcs@gmail.com> Acked-by: Chris Li <chrisl@kernel.org> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Baoquan He <bhe@redhat.com> Cc: Barry Song <baohua@kernel.org> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Jinjiang Tu [Thu, 19 Mar 2026 01:25:41 +0000 (09:25 +0800)]
mm/huge_memory: fix folio isn't locked in softleaf_to_folio()
On arm64 server, we found folio that get from migration entry isn't locked
in softleaf_to_folio(). This issue triggers when mTHP splitting and
zap_nonpresent_ptes() races, and the root cause is lack of memory barrier
in softleaf_to_folio(). The race is as follows:
CPU0 CPU1
deferred_split_scan() zap_nonpresent_ptes()
lock folio
split_folio()
unmap_folio()
change ptes to migration entries
__split_folio_to_order() softleaf_to_folio()
set flags(including PG_locked) for tail pages folio = pfn_folio(softleaf_to_pfn(entry))
smp_wmb() VM_WARN_ON_ONCE(!folio_test_locked(folio))
prep_compound_page() for tail pages
In __split_folio_to_order(), smp_wmb() guarantees page flags of tail pages
are visible before the tail page becomes non-compound. smp_wmb() should
be paired with smp_rmb() in softleaf_to_folio(), which is missed. As a
result, if zap_nonpresent_ptes() accesses migration entry that stores tail
pfn, softleaf_to_folio() may see the updated compound_head of tail page
before page->flags.
This issue will trigger VM_WARN_ON_ONCE() in pfn_swap_entry_folio()
because of the race between folio split and zap_nonpresent_ptes()
leading to a folio incorrectly undergoing modification without a folio
lock being held.
This is a BUG_ON() before commit 93976a20345b ("mm: eliminate further
swapops predicates"), which in merged in v6.19-rc1.
To fix it, add missing smp_rmb() if the softleaf entry is migration entry
in softleaf_to_folio() and softleaf_to_page().
[tujinjiang@huawei.com: update function name and comments] Link: https://lkml.kernel.org/r/20260321075214.3305564-1-tujinjiang@huawei.com Link: https://lkml.kernel.org/r/20260319012541.4158561-1-tujinjiang@huawei.com Fixes: e9b61f19858a ("thp: reintroduce split_huge_page()") Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Cc: Barry Song <baohua@kernel.org> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nanyong Sun <sunnanyong@huawei.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Zi Yan [Mon, 23 Mar 2026 16:37:17 +0000 (12:37 -0400)]
selftests/mm: add folio_split() and filemap_get_entry() race test
The added folio_split_race_test is a modified C port of the race condition
test from [1]. The test creates shmem huge pages, where the main thread
punches holes in the shmem to cause folio_split() in the kernel and a set
of 16 threads reads the shmem to cause filemap_get_entry() in the kernel.
filemap_get_entry() reads the folio and xarray split by folio_split()
locklessly. The original test[2] is written in rust and uses memfd (shmem
backed). This C port uses shmem directly and use a single process.
Note: the initial rust to C conversion is done by Cursor.
Link: https://lore.kernel.org/all/CAKNNEtw5_kZomhkugedKMPOG-sxs5Q5OLumWJdiWXv+C9Yct0w@mail.gmail.com/ Link: https://github.com/dfinity/thp-madv-remove-test Link: https://lkml.kernel.org/r/20260323163717.184107-1-ziy@nvidia.com Co-developed-by: Bas van Dijk <bas@dfinity.org> Signed-off-by: Bas van Dijk <bas@dfinity.org> Co-developed-by: Adam Bratschi-Kaye <adam.bratschikaye@dfinity.org> Signed-off-by: Adam Bratschi-Kaye <adam.bratschikaye@dfinity.org> Signed-off-by: Zi Yan <ziy@nvidia.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Dev Jain <dev.jain@arm.com> Cc: Hugh Dickins <hughd@google.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nico Pache <npache@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Ye Liu [Mon, 23 Mar 2026 09:03:04 +0000 (17:03 +0800)]
mm: remove unused page_is_file_lru() function
The page_is_file_lru() wrapper function is no longer used. The kernel has
moved to folio-based APIs, and all callers should use folio_is_file_lru()
instead.
Remove the obsolete page-based wrapper function.
Link: https://lkml.kernel.org/r/20260323090305.798057-1-ye.liu@linux.dev Signed-off-by: Ye Liu <liuye@kylinos.cn> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Kexin Sun [Sat, 21 Mar 2026 10:57:04 +0000 (18:57 +0800)]
drivers/base/memory: fix stale reference to memory_block_add_nid()
The function memory_block_add_nid() was renamed to
memory_block_add_nid_early() by commit 0a947c14e48c ("drivers/base: move
memory_block_add_nid() into the caller"). Update the stale reference in
add_memory_block().
Assisted-by: unnamed:deepseek-v3.2 coccinelle Link: https://lkml.kernel.org/r/20260321105704.6093-1-kexinsun@smail.nju.edu.cn Signed-off-by: Kexin Sun <kexinsun@smail.nju.edu.cn> Reviewed-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed by: Donet Tom <donettom@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm/page_alloc: don't increase highatomic reserve after pcp alloc
Higher order GFP_ATOMIC allocations can be served through a PCP list with
ALLOC_HIGHATOMIC set. Such an allocation can e.g. happen if a zone is
between the low and min watermarks, and get_page_from_freelist is retried
after the alloc_flags are relaxed.
The call to reserve_highatomic_pageblock() after such a PCP allocation
will result in an increase every single time: the page from the
(unmovable) PCP list will never have migrate type MIGRATE_HIGHATOMIC,
since MIGRATE_HIGHATOMIC pages do not appear on the unmovable PCP list.
So a new pageblock is converted to MIGRATE_HIGHATOMIC.
Eventually that leads to the maximum of 1% of the zone being used up by
(often mostly free) MIGRATE_HIGHATOMIC pageblocks, for no good reason.
Since this space is not available for normal allocations, this wastes
memory and will push things in to reclaim too soon.
This was observed on a system that ran a test with bursts of memory
activity, paired with GFP_ATOMIC SLUB activity. These would lead to a new
slab being allocated with GFP_ATOMIC, sometimes hitting the
get_page_from_freelist retry path by being below the low watermark. While
the frequency of those allocations was low, it kept adding up over time,
and the number of MIGRATE_ATOMIC pageblocks kept increasing.
If a higher order atomic allocation can be served by the unmovable PCP
list, there is probably no need yet to extend the reserves. So, move the
check and possible extension of the highatomic reserves to the buddy case
only, and do not refill the PCP list for ALLOC_HIGHATOMIC if it's empty.
This way, the PCP list is tried for ALLOC_HIGHATOMIC for a fast atomic
allocation. But it will immediately fall back to rmqueue_buddy() if it's
empty. In rmqueue_buddy(), the MIGRATE_HIGHATOMIC buddy lists are tried
first (as before), and the reserves are extended only if that fails.
With this change, the test was stable. Highatomic reserves were built up,
but to a normal level. No highatomic failures were seen.
This is similar to the patch proposed in [1] by Zhiguo Jiang, but
re-arranged a bit.
Link: https://lkml.kernel.org/r/20260320173426.1831267-1-fvdl@google.com Link: https://lore.kernel.org/all/20231122013925.1507-1-justinjiang@vivo.com/ Fixes: 44042b449872 ("mm/page_alloc: allow high-order pages to be stored on the per-cpu lists") Signed-off-by: Zhiguo Jiang <justinjiang@vivo.com> Signed-off-by: Frank van der Linden <fvdl@google.com> Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Cc: Brendan Jackman <jackmanb@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Zhiguo Jiang <justinjiang@vivo.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Bing Jiao [Sat, 21 Mar 2026 03:34:13 +0000 (03:34 +0000)]
mm/memcontrol: fix reclaim_options leak in try_charge_memcg()
In try_charge_memcg(), the 'reclaim_options' variable is initialized once
at the start of the function. However, the function contains a retry
loop. If reclaim_options were modified during an iteration (e.g., by
encountering a memsw limit), the modified state would persist into
subsequent retries.
This leads to incorrect reclaim behavior. Specifically,
MEMCG_RECLAIM_MAY_SWAP is cleared when the combined memcg->memsw limit is
reached. After reclaimation attempts, a subsequent retry may successfully
charge memcg->memsw but fail on the memcg->memory charge. In this case,
swapping should be permitted, but the carried-over state prevents it.
This issue was identified during code reading of try_charge_memcg() while
analyzing memsw limit behavior in tiered-memory systems; no production
failures have been reported yet.
Fix by moving the initialization of 'reclaim_options' inside the retry
loop, ensuring a clean state for every reclaim attempt.
Link: https://lkml.kernel.org/r/20260321033500.2558070-1-bingjiao@google.com Fixes: 6539cc053869 ("mm: memcontrol: fold mem_cgroup_do_charge()") Signed-off-by: Bing Jiao <bingjiao@google.com> Reviewed-by: Yosry Ahmed <yosry@kernel.org> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Baoquan He <bhe@redhat.com> Cc: Barry Song <baohua@kernel.org> Cc: Chris Li <chrisl@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Kairui Song <kasong@tencent.com> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Wei Xu <weixugc@google.com> Cc: Yuanchu Xie <yuanchu@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Baolin Wang [Sat, 21 Mar 2026 06:42:54 +0000 (14:42 +0800)]
mm: change to return bool for the MMU notifier's young flag check
The MMU notifier young flag check related functions only return whether
the young flag was set. Change the return type to bool to make the
intention clearer.
Link: https://lkml.kernel.org/r/a9ad3fe938002d87358e7bfca264f753ab602561.1774075004.git.baolin.wang@linux.alibaba.com Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Baolin Wang [Sat, 21 Mar 2026 06:42:53 +0000 (14:42 +0800)]
mm: change to return bool for pudp_test_and_clear_young()
The pudp_test_and_clear_young() is used to clear the young flag, returning
whether the young flag was set for this PUD entry. Change the return type
to bool to make the intention clearer.
Link: https://lkml.kernel.org/r/2c56fe52c1bf9404145274d7e91d4a65060f6c7c.1774075004.git.baolin.wang@linux.alibaba.com Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Baolin Wang [Sat, 21 Mar 2026 06:42:52 +0000 (14:42 +0800)]
mm: change to return bool for pmdp_clear_flush_young()
The pmdp_clear_flush_young() is used to clear the young flag and flush the
TLB, returning whether the young flag was set for this PMD entry. Change
the return type to bool to make the intention clearer.
Link: https://lkml.kernel.org/r/a668b9a974c0d675e7a41f6973bcbe3336e8b373.1774075004.git.baolin.wang@linux.alibaba.com Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Baolin Wang [Sat, 21 Mar 2026 06:42:51 +0000 (14:42 +0800)]
mm: change to return bool for pmdp_test_and_clear_young()
Callers use pmdp_test_and_clear_young() to clear the young flag and check
whether it was set for this PMD entry. Change the return type to bool to
make the intention clearer.
Link: https://lkml.kernel.org/r/f1d31307a13365d3d0fed5809727dcc2dd59631b.1774075004.git.baolin.wang@linux.alibaba.com Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Baolin Wang [Sat, 21 Mar 2026 06:42:50 +0000 (14:42 +0800)]
mm: change to return bool for ptep_clear_flush_young()/clear_flush_young_ptes()
The ptep_clear_flush_young() and clear_flush_young_ptes() are used to
clear the young flag and flush the TLB, returning whether the young flag
was set. Change the return type to bool to make the intention clearer.
Link: https://lkml.kernel.org/r/24af5144b96103631594501f77d4525f2475c1be.1774075004.git.baolin.wang@linux.alibaba.com Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Baolin Wang [Sat, 21 Mar 2026 06:42:49 +0000 (14:42 +0800)]
mm: change to return bool for ptep_test_and_clear_young()
Patch series "change young flag check functions to return bool", v2.
This is a cleanup patchset to change all young flag check functions to
return bool, as discussed with David in the previous thread[1]. Since
callers only care about whether the young flag was set, returning bool
makes the intention clearer. No functional changes intended.
This patch (of 6):
Callers use ptep_test_and_clear_young() to clear the young flag and check
whether it was set. Change the return type to bool to make the intention
clearer.
Kexin Sun [Sat, 21 Mar 2026 10:58:14 +0000 (18:58 +0800)]
mm: update outdated comments for removed scan_swap_map_slots()
The function scan_swap_map_slots() was removed in commit 0ff67f990bd4
("mm, swap: remove swap slot cache").
The three comments referencing it simply noted that ->flags can be updated
non-atomically by scan_swap_map_slots() to justify a data_race()
annotation. Since the function no longer exists, drop the parenthetical
reference while keeping the data_race() justification intact: ->flags can
still be updated non-atomically by other paths (e.g., swapoff clearing
SWP_WRITEOK).
Assisted-by: unnamed:deepseek-v3.2 coccinelle Link: https://lkml.kernel.org/r/20260321105814.7053-1-kexinsun@smail.nju.edu.cn Signed-off-by: Kexin Sun <kexinsun@smail.nju.edu.cn> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Baoquan He <bhe@redhat.com> Cc: Barry Song <baohua@kernel.org> Cc: Chris Li <chrisl@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Julia Lawall <julia.lawall@inria.fr> Cc: Kairui Song <kasong@tencent.com> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Wei Xu <weixugc@google.com> Cc: Yuanchu Xie <yuanchu@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Kexin Sun [Sat, 21 Mar 2026 10:58:20 +0000 (18:58 +0800)]
mm: vmalloc: update outdated comment for renamed vread()
The function vread() was renamed to vread_iter() in commit 4c91c07c93bb
("mm: vmalloc: convert vread() to vread_iter()"), converting from a
buffer-based to an iterator-based interface.
Update the kdoc of vread_iter() to reflect the new interface: replace
references to @buf with @iter, drop the stale "kernel's buffer"
requirement, and update the self-reference from vread() to vread_iter().
Also update the stale vread() reference in pstore's ram_core.c.
Assisted-by: unnamed:deepseek-v3.2 coccinelle Link: https://lkml.kernel.org/r/20260321105820.7134-1-kexinsun@smail.nju.edu.cn Signed-off-by: Kexin Sun <kexinsun@smail.nju.edu.cn> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: "Guilherme G. Piccoli" <gpiccoli@igalia.com> Cc: Julia Lawall <julia.lawall@inria.fr> Cc: Kees Cook <kees@kernel.org> Cc: Tony Luck <tony.luck@intel.com> Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Kaitao Cheng [Sat, 21 Mar 2026 12:08:47 +0000 (20:08 +0800)]
mm: mark early-init static variables with __meminitdata
Static variables defined inside __meminit functions should also be marked
with __meminitdata, so that their storage is placed in the .init.data
section and reclaimed with free_initmem(), thereby reducing permanent .bss
memory usage when CONFIG_MEMORY_HOTPLUG is disabled.
Link: https://lkml.kernel.org/r/20260321120847.8159-1-pilgrimtao@gmail.com Signed-off-by: Kaitao Cheng <chengkaitao@kylinos.cn> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: David Hildenbrand <david@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Shigeru Yoshida [Sat, 21 Mar 2026 13:29:11 +0000 (22:29 +0900)]
mm/zsmalloc: copy KMSAN metadata in zs_page_migrate()
zs_page_migrate() uses copy_page() to copy the contents of a zspage page
during migration. However, copy_page() is not instrumented by KMSAN, so
the shadow and origin metadata of the destination page are not updated.
As a result, subsequent accesses to the migrated page are reported as
use-after-free by KMSAN, despite the data being correctly copied.
Add a kmsan_copy_page_meta() call after copy_page() to propagate the KMSAN
metadata to the new page, matching what copy_highpage() does internally.
Link: https://lkml.kernel.org/r/20260321132912.93434-1-syoshida@redhat.com Fixes: afb2d666d025 ("zsmalloc: use copy_page for full page copy") Signed-off-by: Shigeru Yoshida <syoshida@redhat.com> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Mark-PK Tsai <mark-pk.tsai@mediatek.com> Cc: Minchan Kim <minchan@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Hubert Mazur [Fri, 20 Mar 2026 07:57:23 +0000 (07:57 +0000)]
mm/execmem: make the populate and alloc atomic
When a block of memory is requested from the execmem manager it tries to
find a suitable fragment by traversing the free_areas. In case there is
no such block, a new memory area is added to the free_areas and then
allocated to the caller by traversing the free_area tree again.
The above operations of allocation and tree traversal are not atomic hence
another request may consume this newly allocated memory block which
results in the allocation failure for the original request. Such
occurrence can be spotted on devices running the 6.18 kernel during the
parallel modules loading.
To mitigate such resource races execute the cache population and
allocation operations under one mutex lock.
Liew Rui Yan [Fri, 20 Mar 2026 05:24:28 +0000 (13:24 +0800)]
Docs/mm/damon: document min_nr_regions constraint and rationale
The current DAMON implementation requires 'min_nr_regions' to be at least
3. However, this constraint is not explicitly documented in the
admin-guide documents, nor is its design rationale explained in the design
document.
Add a section in design.rst to explain the rationale: the virtual address
space monitoring design needs to handle at least three regions to
accommodate two large unmapped areas. While this is specific to 'vaddr',
DAMON currently enforces it across all operation sets for consistency.
Also update reclaim.rst and lru_sort.rst by adding cross-references to
this constraint within their respective 'min_nr_regions' parameter
description sections, ensuring users are aware of the lower bound.
This change is motivated from a recent discussion [1].
Add a kernel-doc-like comment to damos_commit_dests() documenting its
allocation failure contract: on -ENOMEM, the destination structure is left
in a partially torn-down state that is safe to deallocate via
damon_destroy_scheme(), but must not be reused for further commits.
This was unclear from the code alone and led to a separate patch [1]
attempting to reset nr_dests on failure. Make the intended usage explicit
so future readers do not repeat the confusion.
Leno Hou [Wed, 18 Mar 2026 16:30:49 +0000 (00:30 +0800)]
mm/mglru: fix cgroup OOM during MGLRU state switching
When the Multi-Gen LRU (MGLRU) state is toggled dynamically, a race
condition exists between the state switching and the memory reclaim path.
This can lead to unexpected cgroup OOM kills, even when plenty of
reclaimable memory is available.
Problem Description
==================
The issue arises from a "reclaim vacuum" during the transition.
1. When disabling MGLRU, lru_gen_change_state() sets lrugen->enabled to
false before the pages are drained from MGLRU lists back to traditional
LRU lists.
2. Concurrent reclaimers in shrink_lruvec() see lrugen->enabled as false
and skip the MGLRU path.
3. However, these pages might not have reached the traditional LRU lists
yet, or the changes are not yet visible to all CPUs due to a lack
of synchronization.
4. get_scan_count() subsequently finds traditional LRU lists empty,
concludes there is no reclaimable memory, and triggers an OOM kill.
A similar race can occur during enablement, where the reclaimer sees the
new state but the MGLRU lists haven't been populated via fill_evictable()
yet.
Solution
========
Introduce a 'switching' state (`lru_switch`) to bridge the transition.
When transitioning, the system enters this intermediate state where
the reclaimer is forced to attempt both MGLRU and traditional reclaim
paths sequentially. This ensures that folios remain visible to at least
one reclaim mechanism until the transition is fully materialized across
all CPUs.
Race & Mitigation
================
A race window exists between checking the 'draining' state and performing
the actual list operations. For instance, a reclaimer might observe the
draining state as false just before it changes, leading to a suboptimal
reclaim path decision.
However, this impact is effectively mitigated by the kernel's reclaim
retry mechanism (e.g., in do_try_to_free_pages). If a reclaimer pass fails
to find eligible folios due to a state transition race, subsequent retries
in the loop will observe the updated state and correctly direct the scan
to the appropriate LRU lists. This ensures the transient inconsistency
does not escalate into a terminal OOM kill.
This effectively reduce the race window that previously triggered OOMs
under high memory pressure.
This fix has been verified on v7.0.0-rc1; dynamic toggling of MGLRU
functions correctly without triggering unexpected OOM kills.
Link: https://lkml.kernel.org/r/20260319-b4-switch-mglru-v2-v5-1-8898491e5f17@gmail.com Signed-off-by: Leno Hou <lenohou@gmail.com> Acked-by: Yafang Shao <laoar.shao@gmail.com> Reviewed-by: Barry Song <baohua@kernel.org> Reviewed-by: Axel Rasmussen <axelrasmussen@google.com> Cc: Yuanchu Xie <yuanchu@google.com> Cc: Wei Xu <weixugc@google.com> Cc: Jialing Wang <wjl.linux@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Kairui Song <ryncsn@gmail.com> Cc: Bingfang Guo <bfguo@icloud.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
teawater [Thu, 19 Mar 2026 06:59:24 +0000 (14:59 +0800)]
zsmalloc: return -EBUSY for zspage migration lock contention
movable_operations::migrate_page() should return an appropriate error code
for temporary migration failures so the migration core can handle them
correctly.
zs_page_migrate() currently returns -EINVAL when zspage_write_trylock()
fails. That path reflects transient lock contention, not invalid input,
so -EINVAL is clearly wrong.
However, -EAGAIN is also inappropriate here: the zspage's reader-lock
owner may hold the lock for an unbounded duration due to slow
decompression or reader-lock owner preemption. Since migration retries
are bounded by NR_MAX_MIGRATE_PAGES_RETRY and performed with virtually no
delay between attempts, there is no guarantee the lock will be released in
time for a retry to succeed. -EAGAIN implies "try again soon", which does
not hold in this case.
Return -EBUSY instead, which more accurately conveys that the resource is
occupied and migration cannot proceed at this time.
Link: https://lkml.kernel.org/r/20260319065924.69337-1-hui.zhu@linux.dev Signed-off-by: teawater <zhuhui@kylinos.cn> Acked-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm: introduce CONFIG_NUMA_MIGRATION and simplify CONFIG_MIGRATION
CONFIG_MEMORY_HOTREMOVE, CONFIG_COMPACTION and CONFIG_CMA all select
CONFIG_MIGRATION, because they require it to work (users).
Only CONFIG_NUMA_BALANCING and CONFIG_BALLOON_MIGRATION depend on
CONFIG_MIGRATION. CONFIG_BALLOON_MIGRATION is not an actual user, but an
implementation of migration support, so the dependency is correct
(CONFIG_BALLOON_MIGRATION does not make any sense without
CONFIG_MIGRATION).
However, kconfig-language.rst clearly states "In general use select only
for non-visible symbols". So far CONFIG_MIGRATION is user-visible ...
and the dependencies rather confusing.
The whole reason why CONFIG_MIGRATION is user-visible is because of
CONFIG_NUMA: some users might want CONFIG_NUMA but not page migration
support.
Let's clean all that up by introducing a dedicated CONFIG_NUMA_MIGRATION
config option for that purpose only. Make CONFIG_NUMA_BALANCING that so
far depended on CONFIG_NUMA && CONFIG_MIGRATION to depend on
CONFIG_MIGRATION instead. CONFIG_NUMA_MIGRATION will depend on
CONFIG_NUMA && CONFIG_MMU.
CONFIG_NUMA_MIGRATION is user-visible and will default to "y". We use
that default so new configs will automatically enable it, just like it was
the case with CONFIG_MIGRATION. The downside is that some configs that
used to have CONFIG_MIGRATION=n might get it re-enabled by
CONFIG_NUMA_MIGRATION=y, which shouldn't be a problem.
CONFIG_MIGRATION is now a non-visible config option. Any code that select
CONFIG_MIGRATION (as before) must depend directly or indirectly on
CONFIG_MMU.
CONFIG_NUMA_MIGRATION is responsible for any NUMA migration code, which is
mempolicy migration code, memory-tiering code, and move_pages() code in
migrate.c. CONFIG_NUMA_BALANCING uses its functionality.
Note that this implies that with CONFIG_NUMA_MIGRATION=n, move_pages()
will not be available even though CONFIG_MIGRATION=y, which is an expected
change.
In migrate.c, we can remove the CONFIG_NUMA check as both
CONFIG_NUMA_MIGRATION and CONFIG_NUMA_BALANCING depend on it.
With this change, CONFIG_MIGRATION is an internal config, all users of
migration selects CONFIG_MIGRATION, and only CONFIG_BALLOON_MIGRATION
depends on it.
Link: https://lkml.kernel.org/r/20260319-config_migration-v1-2-42270124966f@kernel.org Signed-off-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Acked-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Alistair Popple <apopple@nvidia.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Byungchul Park <byungchul@sk.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Gregory Price <gourry@gourry.net> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "mm: remove CONFIG_ARCH_ENABLE_MEMORY_HOTREMOVE and cleanup
CONFIG_MIGRATION".
While working on memory hotplug code cleanups, I realized that
CONFIG_ARCH_ENABLE_MEMORY_HOTREMOVE is not really required anymore.
Changing that revealed some rather nasty looking CONFIG_MIGRATION
handling.
Let's clean that up by introducing a dedicated CONFIG_NUMA_MIGRATION
option and reducing the dependencies that CONFIG_MIGRATION has.
This patch (of 2):
All architectures that select CONFIG_ARCH_ENABLE_MEMORY_HOTREMOVE also
select CONFIG_ARCH_ENABLE_MEMORY_HOTPLUG. So we can just remove
CONFIG_ARCH_ENABLE_MEMORY_HOTREMOVE.
For CONFIG_MIGRATION, make it depend on CONFIG_MEMORY_HOTREMOVE instead,
and make CONFIG_MEMORY_HOTREMOVE select CONFIG_MIGRATION (just like
CONFIG_CMA and CONFIG_COMPACTION already do).
We'll clean up CONFIG_MIGRATION next.
Link: https://lkml.kernel.org/r/20260319-config_migration-v1-0-42270124966f@kernel.org Link: https://lkml.kernel.org/r/20260319-config_migration-v1-1-42270124966f@kernel.org Signed-off-by: David Hildenbrand (Arm) <david@kernel.org> Acked-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Reviewed-by: Joshua Hahn <joshua.hahnjy@gmail.com> Reviewed-by: Gregory Price <gourry@gourry.net> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Alistair Popple <apopple@nvidia.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Byungchul Park <byungchul@sk.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm/sparse: move memory hotplug bits to sparse-vmemmap.c
Let's move all memory hoptplug related code to sparse-vmemmap.c.
We only have to expose sparse_index_init(). While at it, drop the
definition of sparse_index_init() for !CONFIG_SPARSEMEM, which is unused,
and place the declaration in internal.h.
Link: https://lkml.kernel.org/r/20260320-sparsemem_cleanups-v2-15-096addc8800d@kernel.org Signed-off-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: Wei Xu <weixugc@google.com> Cc: Yuanchu Xie <yuanchu@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm/sparse: move sparse_init_one_section() to internal.h
While at it, convert the BUG_ON to a VM_WARN_ON_ONCE, avoid long lines,
and merge sparse_encode_mem_map() into its only caller
sparse_init_one_section().
Clarify the comment a bit, pointing at page_to_pfn().
[david@kernel.org: s/VM_WARN_ON/VM_WARN_ON_ONCE/] Link: https://lkml.kernel.org/r/6b04c1a1-74e7-42e8-8523-a40802e5dacc@kernel.org Link: https://lkml.kernel.org/r/20260320-sparsemem_cleanups-v2-13-096addc8800d@kernel.org Signed-off-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: Wei Xu <weixugc@google.com> Cc: Yuanchu Xie <yuanchu@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm/sparse: drop set_section_nid() from sparse_add_section()
CONFIG_MEMORY_HOTPLUG is CONFIG_SPARSEMEM_VMEMMAP-only. And
CONFIG_SPARSEMEM_VMEMMAP implies that NODE_NOT_IN_PAGE_FLAGS cannot be
set: see include/linux/page-flags-layout.h
...
#elif defined(CONFIG_SPARSEMEM_VMEMMAP)
#error "Vmemmap: No space for nodes field in page flags"
...
Which implies that the node is always stored in page flags and
NODE_NOT_IN_PAGE_FLAGS cannot be set. Therefore, set_section_nid() is a
NOP on CONFIG_SPARSEMEM_VMEMMAP.
So let's remove the set_section_nid() call to prepare for moving
CONFIG_MEMORY_HOTPLUG to mm/sparse-vmemmap.c
Link: https://lkml.kernel.org/r/20260320-sparsemem_cleanups-v2-12-096addc8800d@kernel.org Signed-off-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: Wei Xu <weixugc@google.com> Cc: Yuanchu Xie <yuanchu@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In 2008, we added through commit 48c906823f39 ("memory hotplug: allocate
usemap on the section with pgdat") quite some complexity to try allocating
memory for the "usemap" (storing pageblock information per memory section)
for a memory section close to the memory of the "pgdat" of the node.
The goal was to make memory hotunplug of boot memory more likely to
succeed. That commit also added some checks for circular dependencies
between two memory sections, whereby two memory sections would contain
each others usemap, turning both boot memory sections un-removable.
However, in 2010, commit a4322e1bad91 ("sparsemem: Put usemap for one node
together") started allocating the usemap for multiple memory sections on
the same node in one chunk, effectively grouping all usemap allocations of
the same node in a single memblock allocation.
We don't really give guarantees about memory hotunplug of boot memory, and
with the change in 2010, it is impossible in practice to get any circular
dependencies.
So let's simply remove this complexity.
Link: https://lkml.kernel.org/r/20260320-sparsemem_cleanups-v2-10-096addc8800d@kernel.org Signed-off-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: Wei Xu <weixugc@google.com> Cc: Yuanchu Xie <yuanchu@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
section_deactivate() applies to CONFIG_SPARSEMEM_VMEMMAP only. So we can
just use pfn_to_page() (after making sure we have the start PFN of the
section), and remove sparse_decode_mem_map().
Link: https://lkml.kernel.org/r/20260320-sparsemem_cleanups-v2-9-096addc8800d@kernel.org Signed-off-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: Wei Xu <weixugc@google.com> Cc: Yuanchu Xie <yuanchu@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm/bootmem_info: avoid using sparse_decode_mem_map()
With SPARSEMEM_VMEMMAP, we can just do a pfn_to_page(). It is not super
clear whether the start_pfn is properly aligned ... so let's just make
sure it is properly aligned to the start of the section.
We will soon might try to remove the bootmem info completely, for now,
just keep it working as is.
Link: https://lkml.kernel.org/r/20260320-sparsemem_cleanups-v2-8-096addc8800d@kernel.org Signed-off-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: Wei Xu <weixugc@google.com> Cc: Yuanchu Xie <yuanchu@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm/bootmem_info: remove handling for !CONFIG_SPARSEMEM_VMEMMAP
It is not immediately obvious that CONFIG_HAVE_BOOTMEM_INFO_NODE is only
selected from CONFIG_MEMORY_HOTREMOVE, which itself depends on
CONFIG_MEMORY_HOTPLUG that ... depends on CONFIG_SPARSEMEM_VMEMMAP.
Let's remove the !CONFIG_SPARSEMEM_VMEMMAP leftovers that are dead code.
Link: https://lkml.kernel.org/r/20260320-sparsemem_cleanups-v2-7-096addc8800d@kernel.org Signed-off-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: Wei Xu <weixugc@google.com> Cc: Yuanchu Xie <yuanchu@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm/Kconfig: make CONFIG_MEMORY_HOTPLUG depend on CONFIG_SPARSEMEM_VMEMMAP
Ever since commit f8f03eb5f0f9 ("mm: stop making SPARSEMEM_VMEMMAP
user-selectable"), an architecture that supports CONFIG_SPARSEMEM_VMEMMAP
(by selecting SPARSEMEM_VMEMMAP_ENABLE) can no longer enable
CONFIG_SPARSEMEM without CONFIG_SPARSEMEM_VMEMMAP.
Right now, CONFIG_MEMORY_HOTPLUG is guarded by CONFIG_SPARSEMEM.
However, CONFIG_ARCH_ENABLE_MEMORY_HOTPLUG is only enabled by
* arm64: which selects SPARSEMEM_VMEMMAP_ENABLE
* loongarch: which selects SPARSEMEM_VMEMMAP_ENABLE
* powerpc (64bit): which selects SPARSEMEM_VMEMMAP_ENABLE
* riscv (64bit): which selects SPARSEMEM_VMEMMAP_ENABLE
* s390 with SPARSEMEM: which selects SPARSEMEM_VMEMMAP_ENABLE
* x86 (64bit): which selects SPARSEMEM_VMEMMAP_ENABLE
So, we can make CONFIG_MEMORY_HOTPLUG depend on CONFIG_SPARSEMEM_VMEMMAP
without affecting any setups.
Link: https://lkml.kernel.org/r/20260320-sparsemem_cleanups-v2-4-096addc8800d@kernel.org Signed-off-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: Wei Xu <weixugc@google.com> Cc: Yuanchu Xie <yuanchu@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm/sparse: remove WARN_ONs from (online|offline)_mem_sections()
We do not allow offlining of memory with memory holes, and always hotplug
memory without holes.
Consequently, we cannot end up onlining or offlining memory sections that
have holes (including invalid sections). That's also why these WARN_ONs
never fired.
Let's remove the WARN_ONs along with the TODO regarding double-checking. Link: https://lkml.kernel.org/r/20260320-sparsemem_cleanups-v2-3-096addc8800d@kernel.org Signed-off-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: Wei Xu <weixugc@google.com> Cc: Yuanchu Xie <yuanchu@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm/memory_hotplug: fix possible race in scan_movable_pages()
Patch series "mm: memory hot(un)plug and SPARSEMEM cleanups", v2.
Some cleanups around memory hot(un)plug and SPARSEMEM. In essence, we can
limit CONFIG_MEMORY_HOTPLUG to CONFIG_SPARSEMEM_VMEMMAP, remove some dead
code, and move all the hotplug bits over to mm/sparse-vmemmap.c.
Some further/related cleanups around other unnecessary code (memory hole
handling and complicated usemap allocation).
I have some further sparse.c cleanups lying around, and I'm planning on
getting rid of bootmem_info.c entirely.
This patch (of 15):
If a hugetlb folio gets freed while we are in scan_movable_pages(),
folio_nr_pages() could return 0, resulting in or'ing "0 - 1 = -1" to the
PFN, resulting in PFN = -1. We're not holding any locks or references
that would prevent that.
for_each_valid_pfn() would then search for the next valid PFN, and could
return a PFN that is outside of the range of the original requested range.
do_migrate_page() would then try to migrate quite a big range, which is
certainly undesirable.
To fix it, simply test for valid folio_nr_pages() values. While at it, as
PageHuge() really just does a page_folio() internally, we can just use
folio_test_hugetlb() on the folio directly.
scan_movable_pages() is expected to be fast, and we try to avoid taking
locks or grabbing references. We cannot use folio_try_get() as that does
not work for free hugetlb folios. We could grab the hugetlb_lock, but
that just adds complexity.
The race is unlikely to trigger in practice, so we won't be CCing stable.
Link: https://lkml.kernel.org/r/20260320-sparsemem_cleanups-v2-0-096addc8800d@kernel.org Link: https://lkml.kernel.org/r/20260320-sparsemem_cleanups-v2-1-096addc8800d@kernel.org Fixes: 16540dae959d ("mm/hugetlb: mm/memory_hotplug: use a folio in scan_movable_pages()") Signed-off-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: Wei Xu <weixugc@google.com> Cc: Yuanchu Xie <yuanchu@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Chen Ni [Wed, 18 Mar 2026 04:38:49 +0000 (12:38 +0800)]
mm/swapfile: remove duplicate include of swap_table.h
Remove duplicate inclusion of swap_table.h in swapfile.c to clean up
redundant code.
Link: https://lkml.kernel.org/r/20260318043849.399266-1-nichen@iscas.ac.cn Signed-off-by: Chen Ni <nichen@iscas.ac.cn> Reviewed-by: SeongJae Park <sj@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Barry Song <baohua@kernel.org> Cc: Chris Li <chrisl@kernel.org> Cc: Kairui Song <kasong@tencent.com> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Nhat Pham <nphamcs@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Asier Gutierrez [Wed, 18 Mar 2026 03:53:47 +0000 (20:53 -0700)]
Docs/mm/damon/design: document DAMON actions when TRANSPARENT_HUGEPAGE is off
MADV_HUGEPAGE and MADV_NOHUGEPAGE are guarded and they are not available
when compiling the kernel without TRANSPARENT_HUGEPAGE option. The DAMON
behaviour is to silently fail [1] in when DAMOS_HUGEPAGE or
DAMOS_NOHUGEPAGE are used, but TRANSPARENT_HUGEPAGE is disabled. Update
the DAMON documentation to reflect this behaviour.
scan_slots_for_writeback() and scan_slots_for_recompress() work in a "best
effort" fashion, if they cannot allocate memory for a new pp-slot
candidate they just return and post-processing selects slots that were
successfully scanned thus far. scan_slots functions never return errors
and their callers never check the return status, so convert them to return
void.
Link: https://lkml.kernel.org/r/20260317032349.753645-1-senozhatsky@chromium.org Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org> Reviewed-by: SeongJae Park <sj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Liew Rui Yan [Sun, 15 Mar 2026 16:29:44 +0000 (09:29 -0700)]
Docs/mm/damon: document exclusivity of special-purpose modules
Add a section in design.rst to explain that DAMON special-purpose kernel
modules (LRU_SORT, RECLAIM, STAT) run in an exclusive manner and return
-EBUSY if another is already running.
Update lru_sort.rst, reclaim.rst and stat.rst by adding cross-references
to this exclusivity rule at the end of their respective Example sections.
This change is motivated from another discussion [1].
Link: https://lkml.kernel.org/r/20260315162945.80994-1-sj@kernel.org Link: https://lore.kernel.org/damon/20260314002119.79742-1-sj@kernel.org/T/#t Signed-off-by: Liew Rui Yan <aethernet65535@gmail.com> Reviewed-by: SeongJae Park <sj@kernel.org> Signed-off-by: SeongJae Park <sj@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Shuah Khan <skhan@linuxfoundation.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When read_from_bdev_async() fails to chain bio, for instance fails to
allocate request or bio, we need to propagate the error condition so that
upper layer is aware of it. zram already does that by setting
BLK_STS_IOERR ->bi_status, but only for sync reads. Change async read
path to return its error status so that async errors are also handled.
Link: https://lkml.kernel.org/r/20260316015354.114465-1-senozhatsky@chromium.org Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org> Suggested-by: Brian Geffon <bgeffon@google.com> Acked-by: Brian Geffon <bgeffon@google.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Richard Chang <richardycc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Calling `LZ4_loadDict()` repeatedly in Zram causes significant overhead
due to its internal dictionary pre-processing. This commit introduces a
template stream mechanism to pre-process the dictionary only once when the
dictionary is initially set or modified. It then efficiently copies this
state for subsequent compressions.
Verification Test Items:
Test Platform: android16-6.12
1. Collect Anonymous Page Dataset
1) Apply the following patch:
static bool zram_meta_alloc(struct zram *zram, u64 disksize)
if (!huge_class_size)
- huge_class_size = zs_huge_class_size(zram->mem_pool);
+ huge_class_size = 0;
2）Install multiple apps and monkey testing until SwapFree is close to 0.
3）Execute the following command to export data:
dd if=/dev/block/zram0 of=/data/samples/zram_dump.img bs=4K
2. Train Dictionary
Since LZ4 does not have a dedicated dictionary training tool, the zstd
tool can be used for training[1]. The command is as follows:
zstd --train /data/samples/* --split=4096 --maxdict=64KB -o /vendor/etc/dict_data
3. Test Code
adb shell "dd if=/data/samples/zram_dump.img of=/dev/test_pattern bs=4096 count=131072 conv=fsync"
adb shell "swapoff /dev/block/zram0"
adb shell "echo 1 > /sys/block/zram0/reset"
adb shell "echo lz4 > /sys/block/zram0/comp_algorithm"
adb shell "echo dict=/vendor/etc/dict_data > /sys/block/zram0/algorithm_params"
adb shell "echo 6G > /sys/block/zram0/disksize"
echo "Start Compression"
adb shell "taskset 80 dd if=/dev/test_pattern of=/dev/block/zram0 bs=4096 count=131072 conv=fsync"
echo.
echo "Start Decompression"
adb shell "taskset 80 dd if=/dev/block/zram0 of=/dev/output_result bs=4096 count=131072 conv=fsync"
echo "mm_stat:"
adb shell "cat /sys/block/zram0/mm_stat"
echo.
Note: To ensure stable test results, it is best to lock the CPU frequency
before executing the test.
LZ4 supports dictionaries up to 64KB. Below are the test results for
compression rates at various dictionary sizes:
dict_size base patch
4 KB 156M/s 219M/s
8 KB 136M/s 217M/s
16KB 98M/s 214M/s
32KB 66M/s 225M/s
64KB 38M/s 224M/s
When an LZ4 compression dictionary is enabled, compression speed is
negatively impacted by the dictionary's size; larger dictionaries result
in slower compression. This patch eliminates the influence of dictionary
size on compression speed, ensuring consistent performance regardless of
dictionary scale.
Nico Pache [Wed, 25 Mar 2026 11:40:22 +0000 (05:40 -0600)]
mm/khugepaged: unify khugepaged and madv_collapse with collapse_single_pmd()
The khugepaged daemon and madvise_collapse have two different
implementations that do almost the same thing. Create collapse_single_pmd
to increase code reuse and create an entry point to these two users.
Refactor madvise_collapse and collapse_scan_mm_slot to use the new
collapse_single_pmd function. To help reduce confusion around the
mmap_locked variable, we rename mmap_locked to lock_dropped in the
collapse_scan_mm_slot() function, and remove the redundant mmap_locked in
madvise_collapse(); this further unifies the code readiblity. the
SCAN_PTE_MAPPED_HUGEPAGE enum is no longer reachable in the
madvise_collapse() function, so we drop it from the list of "continuing"
enums.
This introduces a minor behavioral change that is most likely an
undiscovered bug. The current implementation of khugepaged tests
collapse_test_exit_or_disable() before calling collapse_pte_mapped_thp,
but we weren't doing it in the madvise_collapse case. By unifying these
two callers madvise_collapse now also performs this check. We also modify
the return value to be SCAN_ANY_PROCESS which properly indicates that this
process is no longer valid to operate on.
By moving the madvise_collapse writeback-retry logic into the helper
function we can also avoid having to revalidate the VMA.
We guard the khugepaged_pages_collapsed variable to ensure its only
incremented for khugepaged.
As requested we also convert a VM_BUG_ON to a VM_WARN_ON.
Link: https://lkml.kernel.org/r/20260325114022.444081-6-npache@redhat.com Signed-off-by: Nico Pache <npache@redhat.com> Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Reviewed-by: Lance Yang <lance.yang@linux.dev> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Barry Song <baohua@kernel.org> Cc: Brendan Jackman <jackmanb@google.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David Rientjes <rientjes@google.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Gregory Price <gourry@gourry.net> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nanyong Sun <sunnanyong@huawei.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Peter Xu <peterx@redhat.com> Cc: Rafael Aquini <raquini@redhat.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shivank Garg <shivankg@amd.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Takashi Iwai (SUSE) <tiwai@suse.de> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Usama Arif <usamaarif642@gmail.com> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Will Deacon <will@kernel.org> Cc: Yang Shi <yang@os.amperecomputing.com> Cc: Zach O'Keefe <zokeefe@google.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Nico Pache [Wed, 25 Mar 2026 11:40:21 +0000 (05:40 -0600)]
mm/khugepaged: rename hpage_collapse_* to collapse_*
The hpage_collapse functions describe functions used by madvise_collapse
and khugepaged. remove the unnecessary hpage prefix to shorten the
function name.
Link: https://lkml.kernel.org/r/20260325114022.444081-5-npache@redhat.com Signed-off-by: Nico Pache <npache@redhat.com> Reviewed-by: Dev Jain <dev.jain@arm.com> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Lance Yang <lance.yang@linux.dev> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Barry Song <baohua@kernel.org> Cc: Brendan Jackman <jackmanb@google.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David Rientjes <rientjes@google.com> Cc: Gregory Price <gourry@gourry.net> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nanyong Sun <sunnanyong@huawei.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Peter Xu <peterx@redhat.com> Cc: Rafael Aquini <raquini@redhat.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shivank Garg <shivankg@amd.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Takashi Iwai (SUSE) <tiwai@suse.de> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Usama Arif <usamaarif642@gmail.com> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Cc: Yang Shi <yang@os.amperecomputing.com> Cc: Zach O'Keefe <zokeefe@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Nico Pache [Wed, 25 Mar 2026 11:40:20 +0000 (05:40 -0600)]
mm/khugepaged: define KHUGEPAGED_MAX_PTES_LIMIT as HPAGE_PMD_NR - 1
The value (HPAGE_PMD_NR - 1) is used often in the khugepaged code to
signify the limit of the max_ptes_* values. Add a define for this to
increase code readability and reuse.
Link: https://lkml.kernel.org/r/20260325114022.444081-4-npache@redhat.com Signed-off-by: Nico Pache <npache@redhat.com> Acked-by: Pedro Falcato <pfalcato@suse.de> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Suggested-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Barry Song <baohua@kernel.org> Cc: Brendan Jackman <jackmanb@google.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David Rientjes <rientjes@google.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Gregory Price <gourry@gourry.net> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nanyong Sun <sunnanyong@huawei.com> Cc: Peter Xu <peterx@redhat.com> Cc: Rafael Aquini <raquini@redhat.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shivank Garg <shivankg@amd.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Takashi Iwai (SUSE) <tiwai@suse.de> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Usama Arif <usamaarif642@gmail.com> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Will Deacon <will@kernel.org> Cc: Yang Shi <yang@os.amperecomputing.com> Cc: Zach O'Keefe <zokeefe@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Nico Pache [Wed, 25 Mar 2026 11:40:19 +0000 (05:40 -0600)]
mm: introduce is_pmd_order helper
In order to add mTHP support to khugepaged, we will often be checking if a
given order is (or is not) a PMD order. Some places in the kernel already
use this check, so lets create a simple helper function to keep the code
clean and readable.
Link: https://lkml.kernel.org/r/20260325114022.444081-3-npache@redhat.com Signed-off-by: Nico Pache <npache@redhat.com> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Dev Jain <dev.jain@arm.com> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Lance Yang <lance.yang@linux.dev> Reviewed-by: Barry Song <baohua@kernel.org> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Pedro Falcato <pfalcato@suse.de> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Suggested-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Brendan Jackman <jackmanb@google.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David Rientjes <rientjes@google.com> Cc: Gregory Price <gourry@gourry.net> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nanyong Sun <sunnanyong@huawei.com> Cc: Peter Xu <peterx@redhat.com> Cc: Rafael Aquini <raquini@redhat.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shivank Garg <shivankg@amd.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Takashi Iwai (SUSE) <tiwai@suse.de> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Usama Arif <usamaarif642@gmail.com> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Cc: Yang Shi <yang@os.amperecomputing.com> Cc: Zach O'Keefe <zokeefe@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Nico Pache [Wed, 25 Mar 2026 11:40:18 +0000 (05:40 -0600)]
mm: consolidate anonymous folio PTE mapping into helpers
Patch series "mm: khugepaged cleanups and mTHP prerequisites", v4.
The following series contains cleanups and prerequisites for my work on
khugepaged mTHP support [1]. These have been separated out to ease
review.
The first patch in the series refactors the page fault folio to pte
mapping and follows a similar convention as defined by
map_anon_folio_pmd_(no)pf(). This not only cleans up the current
implementation of do_anonymous_page(), but will allow for reuse later in
the khugepaged mTHP implementation.
The second patch adds a small is_pmd_order() helper to check if an order
is the PMD order. This check is open-coded in a number of places. This
patch aims to clean this up and will be used more in the khugepaged mTHP
work. The third patch also adds a small DEFINE for (HPAGE_PMD_NR - 1)
which is used often across the khugepaged code.
The fourth and fifth patch come from the khugepaged mTHP patchset [1].
These two patches include the rename of function prefixes, and the
unification of khugepaged and madvise_collapse via a new
collapse_single_pmd function.
Patch 1: refactor do_anonymous_page into map_anon_folio_pte_(no)pf
Patch 2: add is_pmd_order helper
Patch 3: Add define for (HPAGE_PMD_NR - 1)
Patch 4: Refactor/rename hpage_collapse
Patch 5: Refactoring to combine madvise_collapse and khugepaged
A big thanks to everyone that has reviewed, tested, and participated in
the development process.
This patch (of 5):
The anonymous page fault handler in do_anonymous_page() open-codes the
sequence to map a newly allocated anonymous folio at the PTE level:
- construct the PTE entry
- add rmap
- add to LRU
- set the PTEs
- update the MMU cache.
Introduce two helpers to consolidate this duplicated logic, mirroring the
existing map_anon_folio_pmd_nopf() pattern for PMD-level mappings:
map_anon_folio_pte_nopf(): constructs the PTE entry, takes folio
references, adds anon rmap and LRU. This function also handles the
uffd_wp that can occur in the pf variant. The future khugepaged mTHP code
calls this to handle mapping the new collapsed mTHP to its folio.
map_anon_folio_pte_pf(): extends the nopf variant to handle MM_ANONPAGES
counter updates, and mTHP fault allocation statistics for the page fault
path.
The zero-page read path in do_anonymous_page() is also untangled from the
shared setpte label, since it does not allocate a folio and should not
share the same mapping sequence as the write path. We can now leave
nr_pages undeclared at the function intialization, and use the single page
update_mmu_cache function to handle the zero page update.
This refactoring will also help reduce code duplication between
mm/memory.c and mm/khugepaged.c, and provides a clean API for PTE-level
anonymous folio mapping that can be reused by future callers (like
khugpeaged mTHP support)
Link: https://lkml.kernel.org/r/20260325114022.444081-1-npache@redhat.com Link: https://lkml.kernel.org/r/20260325114022.444081-2-npache@redhat.com Link: https://lore.kernel.org/all/20260122192841.128719-1-npache@redhat.com Signed-off-by: Nico Pache <npache@redhat.com> Suggested-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Reviewed-by: Dev Jain <dev.jain@arm.com> Reviewed-by: Lance Yang <lance.yang@linux.dev> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Brendan Jackman <jackmanb@google.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David Rientjes <rientjes@google.com> Cc: Gregory Price <gourry@gourry.net> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nanyong Sun <sunnanyong@huawei.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Peter Xu <peterx@redhat.com> Cc: Rafael Aquini <raquini@redhat.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shivank Garg <shivankg@amd.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Takashi Iwai (SUSE) <tiwai@suse.de> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Usama Arif <usamaarif642@gmail.com> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Will Deacon <will@kernel.org> Cc: Yang Shi <yang@os.amperecomputing.com> Cc: Zach O'Keefe <zokeefe@google.com> Cc: Zi Yan <ziy@nvidia.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In mfill_atomic_hugetlb(), linear_page_index() is used to calculate the
page index for hugetlb_fault_mutex_hash(). However, linear_page_index()
returns the index in PAGE_SIZE units, while hugetlb_fault_mutex_hash()
expects the index in huge page units. This mismatch means that different
addresses within the same huge page can produce different hash values,
leading to the use of different mutexes for the same huge page. This can
cause races between faulting threads, which can corrupt the reservation
map and trigger the BUG_ON in resv_map_release().
Fix this by introducing hugetlb_linear_page_index(), which returns the
page index in huge page granularity, and using it in place of
linear_page_index().
Link: https://lkml.kernel.org/r/20260310110526.335749-1-jianhuizzzzz@gmail.com Fixes: a08c7193e4f1 ("mm/filemap: remove hugetlb special casing in filemap.c") Signed-off-by: Jianhui Zhou <jianhuizzzzz@gmail.com> Reported-by: syzbot+f525fd79634858f478e7@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=f525fd79634858f478e7 Acked-by: SeongJae Park <sj@kernel.org> Reviewed-by: David Hildenbrand (Arm) <david@kernel.org> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Jane Chu <jane.chu@oracle.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: JonasZhou <JonasZhou@zhaoxin.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Xu <peterx@redhat.com> Cc: SeongJae Park <sj@kernel.org> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
SeongJae Park [Wed, 11 Mar 2026 05:29:26 +0000 (22:29 -0700)]
mm/damon/lru_sort: respect addr_unit on default monitoring region setup
In the past, damon_set_region_biggest_system_ram_default(), which is the
core function for setting the default monitoring target region of
DAMON_LRU_SORT, didn't support addr_unit. Hence DAMON_LRU_SORT was
silently ignoring the user input for addr_unit when the user doesn't
explicitly set the monitoring target regions, and therefore the default
target region is being used. No real problem from that ignorance was
reported so far. But, the implicit rule is only making things confusing.
Also, the default target region setup function is updated to support
addr_unit. Hence there is no reason to keep ignoring it. Respect the
user-passed addr_unit for the default target monitoring region use case.
SeongJae Park [Wed, 11 Mar 2026 05:29:25 +0000 (22:29 -0700)]
mm/damon/reclaim: respect addr_unit on default monitoring region setup
In the past, damon_set_region_biggest_system_ram_default(), which is the
core function for setting the default monitoring target region of
DAMON_RECLAIM, didn't support addr_unit. Hence DAMON_RECLAIM was silently
ignoring the user input for addr_unit when the user doesn't explicitly set
the monitoring target regions, and therefore the default target region is
being used. No real problem from that ignorance was reported so far.
But, the implicit rule is only making things confusing. Also, the default
target region setup function is updated to support addr_unit. Hence there
is no reason to keep ignoring it. Respect the user-passed addr_unit for
the default target monitoring region use case.
projects / thirdparty / linux.git / log
