<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/tools/testing/vma/tests, branch master</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>mm: remove VMA_IO_BIT check in vma[_flags]_is_mm_managed()</title>
<updated>2026-10-24T08:56:17+00:00</updated>
<author>
<name>Lorenzo Stoakes (ARM)</name>
<email>ljs@kernel.org</email>
</author>
<published>2026-10-13T15:05:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=88d77002e1a133c5d0071b2e7c738c5ab8aa1115'/>
<id>88d77002e1a133c5d0071b2e7c738c5ab8aa1115</id>
<content type='text'>
We have now made it such that every driver which sets VMA_IO_BIT marks it
as not mm-managed.

However, vma_flags_is_mm_managed() still checks for VMA_IO_BIT and, if
set, treats the mapping as not mm-managed. This was previously required to
handle drivers which set VMA_IO_BIT but none of the other flags which
identify a mapping as not mm-managed.

We have now established that a driver which sets VMA_IO_BIT must also set
one of those flags, so the VMA_IO_BIT check is redundant.

So remove the VMA_IO_BIT check in vma_flags_is_mm_managed() and update
mmap_validate_vma_flags() to use vma_flags_is_mm_managed() rather than
open-coding the VMA_PFNMAP_BIT, VMA_MIXEDMAP_BIT check.

This change means that vma[_flags]_can_merge() doesn't check VMA_IO_BIT any
longer (which is now redundant) as it calls vma_flags_is_mm_managed().

Now that the predicate means precisely VMA_PFNMAP_BIT or VMA_MIXEDMAP_BIT,
also use it at the other sites which open-code that pair, so the intent is
stated rather than the flags, with no functional change:

zap_special_vma_range() only zaps mappings which are not mm-managed, as
drivers use it to tear down ranges they established themselves.

The mprotect() arch PFN modification check applies to mappings not managed
by core mm, which may map PFNs without struct pages.

NUMA balancing skips VM_MIXEDMAP mappings having already excluded VM_IO
and VM_PFNMAP mappings via vma_migratable(), so it skips exactly the
mappings not managed by core mm - say so.

Finally, update the VMA userland merge 'special' flag tests to no longer
assert that VMA_IO_BIT prevents merge as VMA_PFNMAP_BIT, VMA_MIXEDMAP_BIT
now suffices.

Link: https://lore.kernel.org/20261013-b4-mmap-prepare-vma-flag-sanify-v6-26-1aa3c9b139f9@kernel.org
Signed-off-by: Lorenzo Stoakes (ARM) &lt;ljs@kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Acked-by: David Hildenbrand (Arm) &lt;david@kernel.org&gt;
Cc: Liam R. Howlett &lt;liam@infradead.org&gt;
Cc: Vlastimil Babka &lt;vbabka@kernel.org&gt;
Cc: Jann Horn &lt;jannh@google.com&gt;
Cc: Pedro Falcato &lt;pfalcato@suse.de&gt;
Cc: Mike Rapoport &lt;rppt@kernel.org&gt;
Cc: Suren Baghdasaryan &lt;surenb@google.com&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Jonathan Corbet &lt;corbet@lwn.net&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: Dennis Dalessandro &lt;dennis.dalessandro@cornelisnetworks.com&gt;
Cc: Jason Gunthorpe &lt;jgg@ziepe.ca&gt;
Cc: Leon Romanovsky &lt;leon@kernel.org&gt;
Cc: Paul Moore &lt;paul@paul-moore.com&gt;
Cc: Stephen Smalley &lt;stephen.smalley.work@gmail.com&gt;
Cc: Jaroslav Kysela &lt;perex@perex.cz&gt;
Cc: Takashi Iwai &lt;tiwai@suse.com&gt;
Cc: Alexei Starovoitov &lt;ast@kernel.org&gt;
Cc: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Cc: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Cc: Eduard Zingerman &lt;eddyz87@gmail.com&gt;
Cc: Kumar Kartikeya Dwivedi &lt;memxor@gmail.com&gt;
Cc: Zi Yan &lt;ziy@nvidia.com&gt;
Cc: Baolin Wang &lt;baolin.wang@linux.alibaba.com&gt;
Cc: Nico Pache &lt;nico.pache@linux.dev&gt;
Cc: Ryan Roberts &lt;ryan.roberts@arm.com&gt;
Cc: Dev Jain &lt;dev.jain@arm.com&gt;
Cc: Barry Song &lt;baohua@kernel.org&gt;
Cc: Lance Yang &lt;lance.yang@linux.dev&gt;
Cc: Usama Arif &lt;usama.arif@linux.dev&gt;
Cc: Kiryl Shutsemau &lt;kas@kernel.org&gt;
Cc: Doug Gilbert &lt;dgilbert@interlog.com&gt;
Cc: James Bottomley &lt;james.bottomley@hansenpartnership.com&gt;
Cc: Martin K. Petersen &lt;mkp@kernel.org&gt;
Cc: Simona Vetter &lt;simona@ffwll.ch&gt;
Cc: Helge Deller &lt;deller@gmx.de&gt;
Cc: Sebastian Reichel &lt;sre@kernel.org&gt;
Cc: John Hubbard &lt;jhubbard@nvidia.com&gt;
Cc: Peter Xu &lt;peterx@redhat.com&gt;
Cc: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@kernel.org&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Cc: Arnaldo Carvalho de Melo &lt;acme@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Rik van Riel &lt;riel@surriel.com&gt;
Cc: Harry Yoo &lt;harry@kernel.org&gt;
Cc: Juri Lelli &lt;juri.lelli@redhat.com&gt;
Cc: Vincent Guittot &lt;vincent.guittot@linaro.org&gt;
Cc: Maarten Lankhorst &lt;maarten.lankhorst@linux.intel.com&gt;
Cc: Maxime Ripard &lt;mripard@kernel.org&gt;
Cc: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Cc: David Airlie &lt;airlied@gmail.com&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Cc: Aneesh Kumar K.V &lt;aneesh.kumar@kernel.org&gt;
Cc: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Muchun Song &lt;muchun.song@linux.dev&gt;
Cc: Oscar Salvador &lt;osalvador@suse.de&gt;
Cc: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Cc: Jan Kara &lt;jack@suse.cz&gt;
Cc: Marc Zyngier &lt;maz@kernel.org&gt;
Cc: Oliver Upton &lt;oupton@kernel.org&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Madhavan Srinivasan &lt;maddy@linux.ibm.com&gt;
Cc: Anup Patel &lt;anup@brainfault.org&gt;
Cc: Paul Walmsley &lt;pjw@kernel.org&gt;
Cc: Palmer Dabbelt &lt;palmer@dabbelt.com&gt;
Cc: Albert Ou &lt;aou@eecs.berkeley.edu&gt;
Cc: Christian Borntraeger &lt;borntraeger@linux.ibm.com&gt;
Cc: Janosch Frank &lt;frankja@linux.ibm.com&gt;
Cc: Claudio Imbrenda &lt;imbrenda@linux.ibm.com&gt;
Cc: Alexander Gordeev &lt;agordeev@linux.ibm.com&gt;
Cc: Gerald Schaefer &lt;gerald.schaefer@linux.ibm.com&gt;
Cc: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Cc: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Cc: David S. Miller &lt;davem@davemloft.net&gt;
Cc: Andreas Larsson &lt;andreas@gaisler.com&gt;
Cc: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Cc: Christian Brauner &lt;brauner@kernel.org&gt;
Cc: Matthew Brost &lt;matthew.brost@intel.com&gt;
Cc: Joshua Hahn &lt;joshua.hahnjy@gmail.com&gt;
Cc: Rakie Kim &lt;rakie.kim@sk.com&gt;
Cc: Byungchul Park &lt;byungchul@sk.com&gt;
Cc: Gregory Price &lt;gourry@gourry.net&gt;
Cc: Ying Huang &lt;ying.huang@linux.alibaba.com&gt;
Cc: Alistair Popple &lt;apopple@nvidia.com&gt;
Cc: Chris Li &lt;chrisl@kernel.org&gt;
Cc: Kairui Song &lt;kasong@tencent.com&gt;
Cc: Kemeng Shi &lt;shikemeng@huaweicloud.com&gt;
Cc: Nhat Pham &lt;nphamcs@gmail.com&gt;
Cc: Baoquan He &lt;baoquan.he@linux.dev&gt;
Cc: Youngjun Park &lt;youngjun.park@lge.com&gt;
Cc: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Cc: Qi Zheng &lt;qi.zheng@linux.dev&gt;
Cc: Shakeel Butt &lt;shakeel.butt@linux.dev&gt;
Cc: Axel Rasmussen &lt;axelrasmussen@google.com&gt;
Cc: Yuanchu Xie &lt;yuanchu@google.com&gt;
Cc: Wei Xu &lt;weixugc@google.com&gt;
Cc: Chengming Zhou &lt;chengming.zhou@linux.dev&gt;
Cc: Michal Hocko &lt;mhocko@kernel.org&gt;
Cc: Miklos Szeredi &lt;miklos@szeredi.hu&gt;
Cc: Xu Xin &lt;xu.xin@linux.dev&gt;
Cc: Ihor Solodrai &lt;ihor.solodrai@linux.dev&gt;
Cc: Bert Karwatzki &lt;spasswolf@web.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
We have now made it such that every driver which sets VMA_IO_BIT marks it
as not mm-managed.

However, vma_flags_is_mm_managed() still checks for VMA_IO_BIT and, if
set, treats the mapping as not mm-managed. This was previously required to
handle drivers which set VMA_IO_BIT but none of the other flags which
identify a mapping as not mm-managed.

We have now established that a driver which sets VMA_IO_BIT must also set
one of those flags, so the VMA_IO_BIT check is redundant.

So remove the VMA_IO_BIT check in vma_flags_is_mm_managed() and update
mmap_validate_vma_flags() to use vma_flags_is_mm_managed() rather than
open-coding the VMA_PFNMAP_BIT, VMA_MIXEDMAP_BIT check.

This change means that vma[_flags]_can_merge() doesn't check VMA_IO_BIT any
longer (which is now redundant) as it calls vma_flags_is_mm_managed().

Now that the predicate means precisely VMA_PFNMAP_BIT or VMA_MIXEDMAP_BIT,
also use it at the other sites which open-code that pair, so the intent is
stated rather than the flags, with no functional change:

zap_special_vma_range() only zaps mappings which are not mm-managed, as
drivers use it to tear down ranges they established themselves.

The mprotect() arch PFN modification check applies to mappings not managed
by core mm, which may map PFNs without struct pages.

NUMA balancing skips VM_MIXEDMAP mappings having already excluded VM_IO
and VM_PFNMAP mappings via vma_migratable(), so it skips exactly the
mappings not managed by core mm - say so.

Finally, update the VMA userland merge 'special' flag tests to no longer
assert that VMA_IO_BIT prevents merge as VMA_PFNMAP_BIT, VMA_MIXEDMAP_BIT
now suffices.

Link: https://lore.kernel.org/20261013-b4-mmap-prepare-vma-flag-sanify-v6-26-1aa3c9b139f9@kernel.org
Signed-off-by: Lorenzo Stoakes (ARM) &lt;ljs@kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Acked-by: David Hildenbrand (Arm) &lt;david@kernel.org&gt;
Cc: Liam R. Howlett &lt;liam@infradead.org&gt;
Cc: Vlastimil Babka &lt;vbabka@kernel.org&gt;
Cc: Jann Horn &lt;jannh@google.com&gt;
Cc: Pedro Falcato &lt;pfalcato@suse.de&gt;
Cc: Mike Rapoport &lt;rppt@kernel.org&gt;
Cc: Suren Baghdasaryan &lt;surenb@google.com&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Jonathan Corbet &lt;corbet@lwn.net&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: Dennis Dalessandro &lt;dennis.dalessandro@cornelisnetworks.com&gt;
Cc: Jason Gunthorpe &lt;jgg@ziepe.ca&gt;
Cc: Leon Romanovsky &lt;leon@kernel.org&gt;
Cc: Paul Moore &lt;paul@paul-moore.com&gt;
Cc: Stephen Smalley &lt;stephen.smalley.work@gmail.com&gt;
Cc: Jaroslav Kysela &lt;perex@perex.cz&gt;
Cc: Takashi Iwai &lt;tiwai@suse.com&gt;
Cc: Alexei Starovoitov &lt;ast@kernel.org&gt;
Cc: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Cc: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Cc: Eduard Zingerman &lt;eddyz87@gmail.com&gt;
Cc: Kumar Kartikeya Dwivedi &lt;memxor@gmail.com&gt;
Cc: Zi Yan &lt;ziy@nvidia.com&gt;
Cc: Baolin Wang &lt;baolin.wang@linux.alibaba.com&gt;
Cc: Nico Pache &lt;nico.pache@linux.dev&gt;
Cc: Ryan Roberts &lt;ryan.roberts@arm.com&gt;
Cc: Dev Jain &lt;dev.jain@arm.com&gt;
Cc: Barry Song &lt;baohua@kernel.org&gt;
Cc: Lance Yang &lt;lance.yang@linux.dev&gt;
Cc: Usama Arif &lt;usama.arif@linux.dev&gt;
Cc: Kiryl Shutsemau &lt;kas@kernel.org&gt;
Cc: Doug Gilbert &lt;dgilbert@interlog.com&gt;
Cc: James Bottomley &lt;james.bottomley@hansenpartnership.com&gt;
Cc: Martin K. Petersen &lt;mkp@kernel.org&gt;
Cc: Simona Vetter &lt;simona@ffwll.ch&gt;
Cc: Helge Deller &lt;deller@gmx.de&gt;
Cc: Sebastian Reichel &lt;sre@kernel.org&gt;
Cc: John Hubbard &lt;jhubbard@nvidia.com&gt;
Cc: Peter Xu &lt;peterx@redhat.com&gt;
Cc: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@kernel.org&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Cc: Arnaldo Carvalho de Melo &lt;acme@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Rik van Riel &lt;riel@surriel.com&gt;
Cc: Harry Yoo &lt;harry@kernel.org&gt;
Cc: Juri Lelli &lt;juri.lelli@redhat.com&gt;
Cc: Vincent Guittot &lt;vincent.guittot@linaro.org&gt;
Cc: Maarten Lankhorst &lt;maarten.lankhorst@linux.intel.com&gt;
Cc: Maxime Ripard &lt;mripard@kernel.org&gt;
Cc: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Cc: David Airlie &lt;airlied@gmail.com&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Cc: Aneesh Kumar K.V &lt;aneesh.kumar@kernel.org&gt;
Cc: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Muchun Song &lt;muchun.song@linux.dev&gt;
Cc: Oscar Salvador &lt;osalvador@suse.de&gt;
Cc: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Cc: Jan Kara &lt;jack@suse.cz&gt;
Cc: Marc Zyngier &lt;maz@kernel.org&gt;
Cc: Oliver Upton &lt;oupton@kernel.org&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Madhavan Srinivasan &lt;maddy@linux.ibm.com&gt;
Cc: Anup Patel &lt;anup@brainfault.org&gt;
Cc: Paul Walmsley &lt;pjw@kernel.org&gt;
Cc: Palmer Dabbelt &lt;palmer@dabbelt.com&gt;
Cc: Albert Ou &lt;aou@eecs.berkeley.edu&gt;
Cc: Christian Borntraeger &lt;borntraeger@linux.ibm.com&gt;
Cc: Janosch Frank &lt;frankja@linux.ibm.com&gt;
Cc: Claudio Imbrenda &lt;imbrenda@linux.ibm.com&gt;
Cc: Alexander Gordeev &lt;agordeev@linux.ibm.com&gt;
Cc: Gerald Schaefer &lt;gerald.schaefer@linux.ibm.com&gt;
Cc: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Cc: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Cc: David S. Miller &lt;davem@davemloft.net&gt;
Cc: Andreas Larsson &lt;andreas@gaisler.com&gt;
Cc: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Cc: Christian Brauner &lt;brauner@kernel.org&gt;
Cc: Matthew Brost &lt;matthew.brost@intel.com&gt;
Cc: Joshua Hahn &lt;joshua.hahnjy@gmail.com&gt;
Cc: Rakie Kim &lt;rakie.kim@sk.com&gt;
Cc: Byungchul Park &lt;byungchul@sk.com&gt;
Cc: Gregory Price &lt;gourry@gourry.net&gt;
Cc: Ying Huang &lt;ying.huang@linux.alibaba.com&gt;
Cc: Alistair Popple &lt;apopple@nvidia.com&gt;
Cc: Chris Li &lt;chrisl@kernel.org&gt;
Cc: Kairui Song &lt;kasong@tencent.com&gt;
Cc: Kemeng Shi &lt;shikemeng@huaweicloud.com&gt;
Cc: Nhat Pham &lt;nphamcs@gmail.com&gt;
Cc: Baoquan He &lt;baoquan.he@linux.dev&gt;
Cc: Youngjun Park &lt;youngjun.park@lge.com&gt;
Cc: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Cc: Qi Zheng &lt;qi.zheng@linux.dev&gt;
Cc: Shakeel Butt &lt;shakeel.butt@linux.dev&gt;
Cc: Axel Rasmussen &lt;axelrasmussen@google.com&gt;
Cc: Yuanchu Xie &lt;yuanchu@google.com&gt;
Cc: Wei Xu &lt;weixugc@google.com&gt;
Cc: Chengming Zhou &lt;chengming.zhou@linux.dev&gt;
Cc: Michal Hocko &lt;mhocko@kernel.org&gt;
Cc: Miklos Szeredi &lt;miklos@szeredi.hu&gt;
Cc: Xu Xin &lt;xu.xin@linux.dev&gt;
Cc: Ihor Solodrai &lt;ihor.solodrai@linux.dev&gt;
Cc: Bert Karwatzki &lt;spasswolf@web.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tools/testing/vma: cover hole filling through __mmap_region()</title>
<updated>2026-10-09T05:55:03+00:00</updated>
<author>
<name>Tianyi Chen</name>
<email>hi@tychen.cc</email>
</author>
<published>2026-09-08T09:55:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=c32fddc0a01da9627789cd5cb3add00b75081da6'/>
<id>c32fddc0a01da9627789cd5cb3add00b75081da6</id>
<content type='text'>
The mmap tests extend existing mappings one neighbor at a time, while
merge tests construct merge state directly.  Neither exercises filling a
hole between compatible mappings through the mmap setup and completion
path.

Fill a gap through __mmap_region() and require both neighbors to merge
into one VMA.  Repeat with only the new mapping's execute permission set
and require three separate VMAs.  Check boundaries, permissions, page
offsets, map_count and cleanup.

Link: https://lore.kernel.org/178886112560.138404.17741948638665342936.vma-v2@tychen.cc
Signed-off-by: Tianyi Chen &lt;hi@tychen.cc&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Reviewed-by: Lorenzo Stoakes (ARM) &lt;ljs@kernel.org&gt;
Assisted-by: Codex:GPT-6
Cc: Jann Horn &lt;jannh@google.com&gt;
Cc: Liam R. Howlett &lt;liam@infradead.org&gt;
Cc: Pedro Falcato &lt;pfalcato@suse.de&gt;
Cc: Vlastimil Babka &lt;vbabka@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The mmap tests extend existing mappings one neighbor at a time, while
merge tests construct merge state directly.  Neither exercises filling a
hole between compatible mappings through the mmap setup and completion
path.

Fill a gap through __mmap_region() and require both neighbors to merge
into one VMA.  Repeat with only the new mapping's execute permission set
and require three separate VMAs.  Check boundaries, permissions, page
offsets, map_count and cleanup.

Link: https://lore.kernel.org/178886112560.138404.17741948638665342936.vma-v2@tychen.cc
Signed-off-by: Tianyi Chen &lt;hi@tychen.cc&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Reviewed-by: Lorenzo Stoakes (ARM) &lt;ljs@kernel.org&gt;
Assisted-by: Codex:GPT-6
Cc: Jann Horn &lt;jannh@google.com&gt;
Cc: Liam R. Howlett &lt;liam@infradead.org&gt;
Cc: Pedro Falcato &lt;pfalcato@suse.de&gt;
Cc: Vlastimil Babka &lt;vbabka@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tools/testing/vma: add test to assert MAP_PRIVATE-/dev/zero is anon</title>
<updated>2026-10-09T05:55:01+00:00</updated>
<author>
<name>Lorenzo Stoakes (ARM)</name>
<email>ljs@kernel.org</email>
</author>
<published>2026-09-26T10:41:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=9a1d31e5a6f3a2989a9afba7a0bc68e7a595604e'/>
<id>9a1d31e5a6f3a2989a9afba7a0bc68e7a595604e</id>
<content type='text'>
Now we've made MAP_PRIVATE-mapped /dev/zero mappings truly anonymous, add a
VMA userland test to assert that this is the case and everything is as we
would expect for an anonymous mapping.

Link: https://lore.kernel.org/20260926-map-private-dev-zero-v3-5-d4781e84ccfc@kernel.org
Signed-off-by: Lorenzo Stoakes (ARM) &lt;ljs@kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Acked-by: David Hildenbrand (Arm) &lt;david@kernel.org&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: Liam R. Howlett &lt;liam@infradead.org&gt;
Cc: Vlastimil Babka &lt;vbabka@kernel.org&gt;
Cc: Jann Horn &lt;jannh@google.com&gt;
Cc: Pedro Falcato &lt;pfalcato@suse.de&gt;
Cc: Mike Rapoport &lt;rppt@kernel.org&gt;
Cc: Suren Baghdasaryan &lt;surenb@google.com&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Hugh Dickins &lt;hughd@google.com&gt;
Cc: Baolin Wang &lt;baolin.wang@linux.alibaba.com&gt;
Cc: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Cc: Jan Kara &lt;jack@suse.cz&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Now we've made MAP_PRIVATE-mapped /dev/zero mappings truly anonymous, add a
VMA userland test to assert that this is the case and everything is as we
would expect for an anonymous mapping.

Link: https://lore.kernel.org/20260926-map-private-dev-zero-v3-5-d4781e84ccfc@kernel.org
Signed-off-by: Lorenzo Stoakes (ARM) &lt;ljs@kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Acked-by: David Hildenbrand (Arm) &lt;david@kernel.org&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: Liam R. Howlett &lt;liam@infradead.org&gt;
Cc: Vlastimil Babka &lt;vbabka@kernel.org&gt;
Cc: Jann Horn &lt;jannh@google.com&gt;
Cc: Pedro Falcato &lt;pfalcato@suse.de&gt;
Cc: Mike Rapoport &lt;rppt@kernel.org&gt;
Cc: Suren Baghdasaryan &lt;surenb@google.com&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Hugh Dickins &lt;hughd@google.com&gt;
Cc: Baolin Wang &lt;baolin.wang@linux.alibaba.com&gt;
Cc: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Cc: Jan Kara &lt;jack@suse.cz&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm/mremap: fix locked_vm leak from MREMAP_DONTUNMAP self-merge</title>
<updated>2026-10-06T23:44:17+00:00</updated>
<author>
<name>Lorenzo Stoakes (ARM)</name>
<email>ljs@kernel.org</email>
</author>
<published>2026-09-30T18:47:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=838bb60dc21553e32df90f2f3bac5b905376e7aa'/>
<id>838bb60dc21553e32df90f2f3bac5b905376e7aa</id>
<content type='text'>
Patch series "mm/mremap: fix two issues with MREMAP_DONTUNMAP", v2.

The MREMAP_DONTUNMAP feature is highly unusual in that it permits mremap()
operations that keep the original VMA in place.

Historically this has led to a lot of bugs where non-obvious interactions
occur between existing mremap() operations and the original VMA.

Commit 397432cab17b ("mm/mremap: account mm-&gt;locked_vm correctly for
MREMAP_DONTUNMAP") fixed an accidentally introduced bug around
mm-&gt;locked_vm accounting, but this wasn't the only issue.

And thus history repeats itself, as it turns out that mm-&gt;locked_vm
accounting is broken by MREMAP_DONTUNMAP yet again by two further cases,
and has been broken ever since the feature was introduced.

Both relate to the fact that VMA_LOCKED_BIT is cleared on the source VMA
(it has to be as all page tables are moved):

1. If an unfaulted VMA_LOCKONFAULT_BIT anonymous VMA self-merges it
   clears the VMA_LOCKED_BIT flag and permanently leaks mm-&gt;locked_vm
   pages.

2. If a partial mremap() is performed on a locked VMA there is a leak equal
   to the number of pages not copied.

(Both for MREMAP_DONTUNMAP operations only)

Both issues can be fixed by treating the source range as distinct from the
destination range, which is the definition of what MREMAP_DONTUNMAP does
so is appropriate.

In case 1, simply disallow the self-merge, keeping adjacent source and
destination VMAs distinct.

In case 2, split the source range ahead of time if the VMA is mlock()'d,
so accounting is always correct.

Both changes were tested locally and confirmed to fix the issues.

For the purposes of a backport, the fixes are kept distinct, a follow-up
series can add self-tests.


This patch (of 2):

The MREMAP_DONTUNMAP feature is highly unusual in that it permits mremap()
operations that keep the original VMA in place.

Historically this has led to a lot of bugs where non-obvious interactions
occur between existing mremap() operations and the original VMA.

Fix another of these - self-merge.

Self-merge occurs when a VMA is moved in front of or behind itself and the
attributes of the VMA permit such a merge.

Practically this can only happen for unfaulted anonymous VMAs due to the
page offset equality requirement for merge:

                           |------------|
                           |            |
                           |            v
        |...........||-----------||...........|
        |           || unfaulted ||           |
        |...........||-----------||...........|
              ^            |
              |            |
              |------------|

This becomes problematic if the VMA is configured by the user to
mlock-on-fault, i.e. the VMA_LOCKED_BIT, VMA_LOCKONFAULT_BIT VMA flags are
set.

MREMAP_DONTUNMAP clears mlock flags for the source VMA and maintains them
for the destination VMA.

Self-merge makes this impossible (there is only one VMA) and incorrectly
clears the destination VMA's mlock flags.

This causes a leak in mm-&gt;locked_vm as clearing this flag does not
decrement the counter and the VMA no longer has VMA_LOCKED_BIT set so it
is not decremented on unmap.

Resolve this by simply disallowing a self-merge in this case - the source
and destination VMAs are kept distinct and then are able to have distinct
mlock() flags.

Update dontunmap_complete() to make the now-redundant self-merge check a
VM_WARN_ON_ONCE() instead to guard against future regressions.

Also update the VMA userland tests to reflect the change.

Link: https://lore.kernel.org/20260930-fix-dontunmap-partial-self-merge-v2-0-f388985a0f0a@kernel.org
Link: https://lore.kernel.org/20260930-fix-dontunmap-partial-self-merge-v2-1-f388985a0f0a@kernel.org
Fixes: e346b3813067 ("mm/mremap: add MREMAP_DONTUNMAP to mremap()")
Signed-off-by: Lorenzo Stoakes (ARM) &lt;ljs@kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Reviewed-by: Pedro Falcato &lt;pfalcato@suse.de&gt;
Acked-by: Kiryl Shutsemau (Meta) &lt;kas@kernel.org&gt;
Reviewed-by: Jose A. Perez de Azpillaga &lt;azpijr@gmail.com&gt;
Tested-by: Anirudh Srinivasan &lt;asrinivasan@oss.tenstorrent.com&gt;
Cc: Liam R. Howlett &lt;liam@infradead.org&gt;
Cc: Vlastimil Babka &lt;vbabka@kernel.org&gt;
Cc: Jann Horn &lt;jannh@google.com&gt;
Cc: Brian Geffon &lt;bgeffon@google.com&gt;
Cc: Minchan Kim &lt;minchan@kernel.org&gt;
Cc: &lt;stable@vger.kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Patch series "mm/mremap: fix two issues with MREMAP_DONTUNMAP", v2.

The MREMAP_DONTUNMAP feature is highly unusual in that it permits mremap()
operations that keep the original VMA in place.

Historically this has led to a lot of bugs where non-obvious interactions
occur between existing mremap() operations and the original VMA.

Commit 397432cab17b ("mm/mremap: account mm-&gt;locked_vm correctly for
MREMAP_DONTUNMAP") fixed an accidentally introduced bug around
mm-&gt;locked_vm accounting, but this wasn't the only issue.

And thus history repeats itself, as it turns out that mm-&gt;locked_vm
accounting is broken by MREMAP_DONTUNMAP yet again by two further cases,
and has been broken ever since the feature was introduced.

Both relate to the fact that VMA_LOCKED_BIT is cleared on the source VMA
(it has to be as all page tables are moved):

1. If an unfaulted VMA_LOCKONFAULT_BIT anonymous VMA self-merges it
   clears the VMA_LOCKED_BIT flag and permanently leaks mm-&gt;locked_vm
   pages.

2. If a partial mremap() is performed on a locked VMA there is a leak equal
   to the number of pages not copied.

(Both for MREMAP_DONTUNMAP operations only)

Both issues can be fixed by treating the source range as distinct from the
destination range, which is the definition of what MREMAP_DONTUNMAP does
so is appropriate.

In case 1, simply disallow the self-merge, keeping adjacent source and
destination VMAs distinct.

In case 2, split the source range ahead of time if the VMA is mlock()'d,
so accounting is always correct.

Both changes were tested locally and confirmed to fix the issues.

For the purposes of a backport, the fixes are kept distinct, a follow-up
series can add self-tests.


This patch (of 2):

The MREMAP_DONTUNMAP feature is highly unusual in that it permits mremap()
operations that keep the original VMA in place.

Historically this has led to a lot of bugs where non-obvious interactions
occur between existing mremap() operations and the original VMA.

Fix another of these - self-merge.

Self-merge occurs when a VMA is moved in front of or behind itself and the
attributes of the VMA permit such a merge.

Practically this can only happen for unfaulted anonymous VMAs due to the
page offset equality requirement for merge:

                           |------------|
                           |            |
                           |            v
        |...........||-----------||...........|
        |           || unfaulted ||           |
        |...........||-----------||...........|
              ^            |
              |            |
              |------------|

This becomes problematic if the VMA is configured by the user to
mlock-on-fault, i.e. the VMA_LOCKED_BIT, VMA_LOCKONFAULT_BIT VMA flags are
set.

MREMAP_DONTUNMAP clears mlock flags for the source VMA and maintains them
for the destination VMA.

Self-merge makes this impossible (there is only one VMA) and incorrectly
clears the destination VMA's mlock flags.

This causes a leak in mm-&gt;locked_vm as clearing this flag does not
decrement the counter and the VMA no longer has VMA_LOCKED_BIT set so it
is not decremented on unmap.

Resolve this by simply disallowing a self-merge in this case - the source
and destination VMAs are kept distinct and then are able to have distinct
mlock() flags.

Update dontunmap_complete() to make the now-redundant self-merge check a
VM_WARN_ON_ONCE() instead to guard against future regressions.

Also update the VMA userland tests to reflect the change.

Link: https://lore.kernel.org/20260930-fix-dontunmap-partial-self-merge-v2-0-f388985a0f0a@kernel.org
Link: https://lore.kernel.org/20260930-fix-dontunmap-partial-self-merge-v2-1-f388985a0f0a@kernel.org
Fixes: e346b3813067 ("mm/mremap: add MREMAP_DONTUNMAP to mremap()")
Signed-off-by: Lorenzo Stoakes (ARM) &lt;ljs@kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Reviewed-by: Pedro Falcato &lt;pfalcato@suse.de&gt;
Acked-by: Kiryl Shutsemau (Meta) &lt;kas@kernel.org&gt;
Reviewed-by: Jose A. Perez de Azpillaga &lt;azpijr@gmail.com&gt;
Tested-by: Anirudh Srinivasan &lt;asrinivasan@oss.tenstorrent.com&gt;
Cc: Liam R. Howlett &lt;liam@infradead.org&gt;
Cc: Vlastimil Babka &lt;vbabka@kernel.org&gt;
Cc: Jann Horn &lt;jannh@google.com&gt;
Cc: Brian Geffon &lt;bgeffon@google.com&gt;
Cc: Minchan Kim &lt;minchan@kernel.org&gt;
Cc: &lt;stable@vger.kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tools/testing/vma: expand VMA merge tests to assert anon pgoff</title>
<updated>2026-08-25T01:42:53+00:00</updated>
<author>
<name>Lorenzo Stoakes (ARM)</name>
<email>ljs@kernel.org</email>
</author>
<published>2026-08-13T17:32:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=6b7460ad1af8b10cc6b629649979d9d0d844046e'/>
<id>6b7460ad1af8b10cc6b629649979d9d0d844046e</id>
<content type='text'>
Now we have introduced the VMA anonymous page offset attribute and update
it when VMAs are manipulated, update VMA merge tests to assert that the
anonymous page offset is as expected.

Also update instances where we could use vma_start_pgoff() to do so.

Link: https://lore.kernel.org/20260813-b4-scalable-cow-virt-pgoff-v5-15-c21581c0c3c8@kernel.org
Signed-off-by: Lorenzo Stoakes (ARM) &lt;ljs@kernel.org&gt;
Acked-by: David Hildenbrand (Arm) &lt;david@kernel.org&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Alexander Deucher &lt;alexander.deucher@amd.com&gt;
Cc: Alexander Gordeev &lt;agordeev@linux.ibm.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Alistair Popple &lt;apopple@nvidia.com&gt;
Cc: Arnaldo Carvalho de Melo &lt;acme@kernel.org&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Baolin Wang &lt;baolin.wang@linux.alibaba.com&gt;
Cc: Baoquan He &lt;baoquan.he@linux.dev&gt;
Cc: Barry Song &lt;baohua@kernel.org&gt;
Cc: Boris Brezillon &lt;boris.brezillon@collabora.com&gt;
Cc: Byungchul Park &lt;byungchul@sk.com&gt;
Cc: Chengming Zhou &lt;chengming.zhou@linux.dev&gt;
Cc: Chris Li &lt;chrisl@kernel.org&gt;
Cc: Christan König &lt;christian.koenig@amd.com&gt;
Cc: Christian Borntraeger &lt;borntraeger@linux.ibm.com&gt;
Cc: Claudio Imbrenda &lt;imbrenda@linux.ibm.com&gt;
Cc: Dave Airlie &lt;airlied@gmail.com&gt;
Cc: Dev Jain &lt;dev.jain@arm.com&gt;
Cc: Gerald Schaefer &lt;gerald.schaefer@linux.ibm.com&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: Gregory Price (Meta) &lt;gourry@gourry.net&gt;
Cc: Harry Yoo &lt;harry@kernel.org&gt;
Cc: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Cc: Huang Ray &lt;Ray.Huang@amd.com&gt;
Cc: "Huang, Ying" &lt;ying.huang@linux.alibaba.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: James Clark &lt;james.clark@linaro.org&gt;
Cc: Jan Kara &lt;jack@suse.cz&gt;
Cc: Jann Horn &lt;jannh@google.com&gt;
Cc: Janosch Frank &lt;frankja@linux.ibm.com&gt;
Cc: Jason Gunthorpe &lt;jgg@ziepe.ca&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: John Hubbard &lt;jhubbard@nvidia.com&gt;
Cc: Joshua Hahn &lt;joshua.hahnjy@gmail.com&gt;
Cc: Kairui Song &lt;kasong@tencent.com&gt;
Cc: Kees Cook &lt;kees@kernel.org&gt;
Cc: Kemeng Shi &lt;shikemeng@huaweicloud.com&gt;
Cc: Lance Yang &lt;lance.yang@linux.dev&gt;
Cc: Liam R. Howlett &lt;liam@infradead.org&gt;
Cc: Liviu Dudau &lt;liviu.dudau@arm.com&gt;
Cc: Maarten Lankhorst &lt;maarten.lankhorst@linux.intel.com&gt;
Cc: Marc Rutland &lt;mark.rutland@arm.com&gt;
Cc: "Masami Hiramatsu (Google)" &lt;mhiramat@kernel.org&gt;
Cc: Matthew Auld &lt;matthew.auld@intel.com&gt;
Cc: Matthew Brost &lt;matthew.brost@intel.com&gt;
Cc: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Cc: Maxime Ripard &lt;mripard@kernel.org&gt;
Cc: Miaohe Lin &lt;linmiaohe@huawei.com&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Mike Rapoport &lt;rppt@kernel.org&gt;
Cc: Muchun Song &lt;muchun.song@linux.dev&gt;
Cc: Namhyung kim &lt;namhyung@kernel.org&gt;
Cc: Naoya Horiguchi &lt;nao.horiguchi@gmail.com&gt;
Cc: Nhat Pham &lt;nphamcs@gmail.com&gt;
Cc: Nico Pache &lt;npache@redhat.com&gt;
Cc: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: Oscar Salvador &lt;osalvador@suse.de&gt;
Cc: Pedro Falcato &lt;pfalcato@suse.de&gt;
Cc: Peter Xu &lt;peterx@redhat.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Rakie Kim &lt;rakie.kim@sk.com&gt;
Cc: Rik van Riel &lt;riel@surriel.com&gt;
Cc: Rodrigo Vivi &lt;rodrigo.vivi@intel.com&gt;
Cc: Ryan Roberts &lt;ryan.roberts@arm.com&gt;
Cc: Steven Price &lt;steven.price@arm.com&gt;
Cc: Suren Baghdasaryan &lt;surenb@google.com&gt;
Cc: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Cc: Thomas Hellström &lt;thomas.hellstrom@linux.intel.com&gt;
Cc: Thomas Zimemrmann &lt;tzimmermann@suse.de&gt;
Cc: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Cc: Vlastimil Babka &lt;vbabka@kernel.org&gt;
Cc: xu xin &lt;xu.xin16@zte.com.cn&gt;
Cc: Zi Yan &lt;ziy@nvidia.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Now we have introduced the VMA anonymous page offset attribute and update
it when VMAs are manipulated, update VMA merge tests to assert that the
anonymous page offset is as expected.

Also update instances where we could use vma_start_pgoff() to do so.

Link: https://lore.kernel.org/20260813-b4-scalable-cow-virt-pgoff-v5-15-c21581c0c3c8@kernel.org
Signed-off-by: Lorenzo Stoakes (ARM) &lt;ljs@kernel.org&gt;
Acked-by: David Hildenbrand (Arm) &lt;david@kernel.org&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Alexander Deucher &lt;alexander.deucher@amd.com&gt;
Cc: Alexander Gordeev &lt;agordeev@linux.ibm.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Alistair Popple &lt;apopple@nvidia.com&gt;
Cc: Arnaldo Carvalho de Melo &lt;acme@kernel.org&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Baolin Wang &lt;baolin.wang@linux.alibaba.com&gt;
Cc: Baoquan He &lt;baoquan.he@linux.dev&gt;
Cc: Barry Song &lt;baohua@kernel.org&gt;
Cc: Boris Brezillon &lt;boris.brezillon@collabora.com&gt;
Cc: Byungchul Park &lt;byungchul@sk.com&gt;
Cc: Chengming Zhou &lt;chengming.zhou@linux.dev&gt;
Cc: Chris Li &lt;chrisl@kernel.org&gt;
Cc: Christan König &lt;christian.koenig@amd.com&gt;
Cc: Christian Borntraeger &lt;borntraeger@linux.ibm.com&gt;
Cc: Claudio Imbrenda &lt;imbrenda@linux.ibm.com&gt;
Cc: Dave Airlie &lt;airlied@gmail.com&gt;
Cc: Dev Jain &lt;dev.jain@arm.com&gt;
Cc: Gerald Schaefer &lt;gerald.schaefer@linux.ibm.com&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: Gregory Price (Meta) &lt;gourry@gourry.net&gt;
Cc: Harry Yoo &lt;harry@kernel.org&gt;
Cc: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Cc: Huang Ray &lt;Ray.Huang@amd.com&gt;
Cc: "Huang, Ying" &lt;ying.huang@linux.alibaba.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: James Clark &lt;james.clark@linaro.org&gt;
Cc: Jan Kara &lt;jack@suse.cz&gt;
Cc: Jann Horn &lt;jannh@google.com&gt;
Cc: Janosch Frank &lt;frankja@linux.ibm.com&gt;
Cc: Jason Gunthorpe &lt;jgg@ziepe.ca&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: John Hubbard &lt;jhubbard@nvidia.com&gt;
Cc: Joshua Hahn &lt;joshua.hahnjy@gmail.com&gt;
Cc: Kairui Song &lt;kasong@tencent.com&gt;
Cc: Kees Cook &lt;kees@kernel.org&gt;
Cc: Kemeng Shi &lt;shikemeng@huaweicloud.com&gt;
Cc: Lance Yang &lt;lance.yang@linux.dev&gt;
Cc: Liam R. Howlett &lt;liam@infradead.org&gt;
Cc: Liviu Dudau &lt;liviu.dudau@arm.com&gt;
Cc: Maarten Lankhorst &lt;maarten.lankhorst@linux.intel.com&gt;
Cc: Marc Rutland &lt;mark.rutland@arm.com&gt;
Cc: "Masami Hiramatsu (Google)" &lt;mhiramat@kernel.org&gt;
Cc: Matthew Auld &lt;matthew.auld@intel.com&gt;
Cc: Matthew Brost &lt;matthew.brost@intel.com&gt;
Cc: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Cc: Maxime Ripard &lt;mripard@kernel.org&gt;
Cc: Miaohe Lin &lt;linmiaohe@huawei.com&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Mike Rapoport &lt;rppt@kernel.org&gt;
Cc: Muchun Song &lt;muchun.song@linux.dev&gt;
Cc: Namhyung kim &lt;namhyung@kernel.org&gt;
Cc: Naoya Horiguchi &lt;nao.horiguchi@gmail.com&gt;
Cc: Nhat Pham &lt;nphamcs@gmail.com&gt;
Cc: Nico Pache &lt;npache@redhat.com&gt;
Cc: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: Oscar Salvador &lt;osalvador@suse.de&gt;
Cc: Pedro Falcato &lt;pfalcato@suse.de&gt;
Cc: Peter Xu &lt;peterx@redhat.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Rakie Kim &lt;rakie.kim@sk.com&gt;
Cc: Rik van Riel &lt;riel@surriel.com&gt;
Cc: Rodrigo Vivi &lt;rodrigo.vivi@intel.com&gt;
Cc: Ryan Roberts &lt;ryan.roberts@arm.com&gt;
Cc: Steven Price &lt;steven.price@arm.com&gt;
Cc: Suren Baghdasaryan &lt;surenb@google.com&gt;
Cc: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Cc: Thomas Hellström &lt;thomas.hellstrom@linux.intel.com&gt;
Cc: Thomas Zimemrmann &lt;tzimmermann@suse.de&gt;
Cc: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Cc: Vlastimil Babka &lt;vbabka@kernel.org&gt;
Cc: xu xin &lt;xu.xin16@zte.com.cn&gt;
Cc: Zi Yan &lt;ziy@nvidia.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: propagate VMA anonymous page offset on map, remap, split + merge</title>
<updated>2026-08-25T01:42:52+00:00</updated>
<author>
<name>Lorenzo Stoakes (ARM)</name>
<email>ljs@kernel.org</email>
</author>
<published>2026-08-13T17:32:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=6a993c7fbc3e99431e148eb261c9b2e38525fce4'/>
<id>6a993c7fbc3e99431e148eb261c9b2e38525fce4</id>
<content type='text'>
We must correctly update VMA anonymous page offset state on all VMA
operations that would result in it changing, with special attention given
to remapping.

We cover most cases by simply updating vma_set_range() to do so (with a
new anonymous page offset parameter), but also notably must update the
merging and mapping logic to propagate this parameter correctly.

The remap logic remains the same - we may update the anonymous page offset
if the VMA is unfaulted, but now this applies to MAP_PRIVATE file-backed
mappings too, so we update the code to reflect this.

Note that we use __linear_anon_page_index() upon remap as the VMA may be
shared, in order that we update the field consistently regardless of VMA
type.

Similarly, pass through anon page offset to the merge logic, updating the
vma_merge_struct struct to propagate it, and also use
__linear_anon_page_index() to obtain the anonymous page index so it can be
safely used for both shared and MAP_PRIVATE file-backed mappings.

In copy_vma(), the anonymous page offset is updated regardless of whether
the mapping is a CoW mapping or not.  This is both to keep the anonymous
page offset consistent even for non-CoW mappings (it is set so should at
least remain correct) and makes the logic cleaner.

A self-merge however remains permitted only for mappings which can have a
populated vma-&gt;anon_vma and do not require alignment on a separate file
offset - that is pure anonymous VMAs, so only set can_self_merge if
vma_is_anonymous().

Finally, we update insert_vm_struct() to correctly set the anonymous page
offset on insertion of a VMA.

We simply ensure state is correctly propagated here, so no functional
changes are intended.

Also update VMA userland tests to reflect this change.

Link: https://lore.kernel.org/20260813-b4-scalable-cow-virt-pgoff-v5-9-c21581c0c3c8@kernel.org
Signed-off-by: Lorenzo Stoakes (ARM) &lt;ljs@kernel.org&gt;
Acked-by: David Hildenbrand (Arm) &lt;david@kernel.org&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Alexander Deucher &lt;alexander.deucher@amd.com&gt;
Cc: Alexander Gordeev &lt;agordeev@linux.ibm.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Alistair Popple &lt;apopple@nvidia.com&gt;
Cc: Arnaldo Carvalho de Melo &lt;acme@kernel.org&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Baolin Wang &lt;baolin.wang@linux.alibaba.com&gt;
Cc: Baoquan He &lt;baoquan.he@linux.dev&gt;
Cc: Barry Song &lt;baohua@kernel.org&gt;
Cc: Boris Brezillon &lt;boris.brezillon@collabora.com&gt;
Cc: Byungchul Park &lt;byungchul@sk.com&gt;
Cc: Chengming Zhou &lt;chengming.zhou@linux.dev&gt;
Cc: Chris Li &lt;chrisl@kernel.org&gt;
Cc: Christan König &lt;christian.koenig@amd.com&gt;
Cc: Christian Borntraeger &lt;borntraeger@linux.ibm.com&gt;
Cc: Claudio Imbrenda &lt;imbrenda@linux.ibm.com&gt;
Cc: Dave Airlie &lt;airlied@gmail.com&gt;
Cc: Dev Jain &lt;dev.jain@arm.com&gt;
Cc: Gerald Schaefer &lt;gerald.schaefer@linux.ibm.com&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: Gregory Price (Meta) &lt;gourry@gourry.net&gt;
Cc: Harry Yoo &lt;harry@kernel.org&gt;
Cc: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Cc: Huang Ray &lt;Ray.Huang@amd.com&gt;
Cc: "Huang, Ying" &lt;ying.huang@linux.alibaba.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: James Clark &lt;james.clark@linaro.org&gt;
Cc: Jan Kara &lt;jack@suse.cz&gt;
Cc: Jann Horn &lt;jannh@google.com&gt;
Cc: Janosch Frank &lt;frankja@linux.ibm.com&gt;
Cc: Jason Gunthorpe &lt;jgg@ziepe.ca&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: John Hubbard &lt;jhubbard@nvidia.com&gt;
Cc: Joshua Hahn &lt;joshua.hahnjy@gmail.com&gt;
Cc: Kairui Song &lt;kasong@tencent.com&gt;
Cc: Kees Cook &lt;kees@kernel.org&gt;
Cc: Kemeng Shi &lt;shikemeng@huaweicloud.com&gt;
Cc: Lance Yang &lt;lance.yang@linux.dev&gt;
Cc: Liam R. Howlett &lt;liam@infradead.org&gt;
Cc: Liviu Dudau &lt;liviu.dudau@arm.com&gt;
Cc: Maarten Lankhorst &lt;maarten.lankhorst@linux.intel.com&gt;
Cc: Marc Rutland &lt;mark.rutland@arm.com&gt;
Cc: "Masami Hiramatsu (Google)" &lt;mhiramat@kernel.org&gt;
Cc: Matthew Auld &lt;matthew.auld@intel.com&gt;
Cc: Matthew Brost &lt;matthew.brost@intel.com&gt;
Cc: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Cc: Maxime Ripard &lt;mripard@kernel.org&gt;
Cc: Miaohe Lin &lt;linmiaohe@huawei.com&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Mike Rapoport &lt;rppt@kernel.org&gt;
Cc: Muchun Song &lt;muchun.song@linux.dev&gt;
Cc: Namhyung kim &lt;namhyung@kernel.org&gt;
Cc: Naoya Horiguchi &lt;nao.horiguchi@gmail.com&gt;
Cc: Nhat Pham &lt;nphamcs@gmail.com&gt;
Cc: Nico Pache &lt;npache@redhat.com&gt;
Cc: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: Oscar Salvador &lt;osalvador@suse.de&gt;
Cc: Pedro Falcato &lt;pfalcato@suse.de&gt;
Cc: Peter Xu &lt;peterx@redhat.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Rakie Kim &lt;rakie.kim@sk.com&gt;
Cc: Rik van Riel &lt;riel@surriel.com&gt;
Cc: Rodrigo Vivi &lt;rodrigo.vivi@intel.com&gt;
Cc: Ryan Roberts &lt;ryan.roberts@arm.com&gt;
Cc: Steven Price &lt;steven.price@arm.com&gt;
Cc: Suren Baghdasaryan &lt;surenb@google.com&gt;
Cc: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Cc: Thomas Hellström &lt;thomas.hellstrom@linux.intel.com&gt;
Cc: Thomas Zimemrmann &lt;tzimmermann@suse.de&gt;
Cc: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Cc: Vlastimil Babka &lt;vbabka@kernel.org&gt;
Cc: xu xin &lt;xu.xin16@zte.com.cn&gt;
Cc: Zi Yan &lt;ziy@nvidia.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
We must correctly update VMA anonymous page offset state on all VMA
operations that would result in it changing, with special attention given
to remapping.

We cover most cases by simply updating vma_set_range() to do so (with a
new anonymous page offset parameter), but also notably must update the
merging and mapping logic to propagate this parameter correctly.

The remap logic remains the same - we may update the anonymous page offset
if the VMA is unfaulted, but now this applies to MAP_PRIVATE file-backed
mappings too, so we update the code to reflect this.

Note that we use __linear_anon_page_index() upon remap as the VMA may be
shared, in order that we update the field consistently regardless of VMA
type.

Similarly, pass through anon page offset to the merge logic, updating the
vma_merge_struct struct to propagate it, and also use
__linear_anon_page_index() to obtain the anonymous page index so it can be
safely used for both shared and MAP_PRIVATE file-backed mappings.

In copy_vma(), the anonymous page offset is updated regardless of whether
the mapping is a CoW mapping or not.  This is both to keep the anonymous
page offset consistent even for non-CoW mappings (it is set so should at
least remain correct) and makes the logic cleaner.

A self-merge however remains permitted only for mappings which can have a
populated vma-&gt;anon_vma and do not require alignment on a separate file
offset - that is pure anonymous VMAs, so only set can_self_merge if
vma_is_anonymous().

Finally, we update insert_vm_struct() to correctly set the anonymous page
offset on insertion of a VMA.

We simply ensure state is correctly propagated here, so no functional
changes are intended.

Also update VMA userland tests to reflect this change.

Link: https://lore.kernel.org/20260813-b4-scalable-cow-virt-pgoff-v5-9-c21581c0c3c8@kernel.org
Signed-off-by: Lorenzo Stoakes (ARM) &lt;ljs@kernel.org&gt;
Acked-by: David Hildenbrand (Arm) &lt;david@kernel.org&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Alexander Deucher &lt;alexander.deucher@amd.com&gt;
Cc: Alexander Gordeev &lt;agordeev@linux.ibm.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Alistair Popple &lt;apopple@nvidia.com&gt;
Cc: Arnaldo Carvalho de Melo &lt;acme@kernel.org&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Baolin Wang &lt;baolin.wang@linux.alibaba.com&gt;
Cc: Baoquan He &lt;baoquan.he@linux.dev&gt;
Cc: Barry Song &lt;baohua@kernel.org&gt;
Cc: Boris Brezillon &lt;boris.brezillon@collabora.com&gt;
Cc: Byungchul Park &lt;byungchul@sk.com&gt;
Cc: Chengming Zhou &lt;chengming.zhou@linux.dev&gt;
Cc: Chris Li &lt;chrisl@kernel.org&gt;
Cc: Christan König &lt;christian.koenig@amd.com&gt;
Cc: Christian Borntraeger &lt;borntraeger@linux.ibm.com&gt;
Cc: Claudio Imbrenda &lt;imbrenda@linux.ibm.com&gt;
Cc: Dave Airlie &lt;airlied@gmail.com&gt;
Cc: Dev Jain &lt;dev.jain@arm.com&gt;
Cc: Gerald Schaefer &lt;gerald.schaefer@linux.ibm.com&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: Gregory Price (Meta) &lt;gourry@gourry.net&gt;
Cc: Harry Yoo &lt;harry@kernel.org&gt;
Cc: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Cc: Huang Ray &lt;Ray.Huang@amd.com&gt;
Cc: "Huang, Ying" &lt;ying.huang@linux.alibaba.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: James Clark &lt;james.clark@linaro.org&gt;
Cc: Jan Kara &lt;jack@suse.cz&gt;
Cc: Jann Horn &lt;jannh@google.com&gt;
Cc: Janosch Frank &lt;frankja@linux.ibm.com&gt;
Cc: Jason Gunthorpe &lt;jgg@ziepe.ca&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: John Hubbard &lt;jhubbard@nvidia.com&gt;
Cc: Joshua Hahn &lt;joshua.hahnjy@gmail.com&gt;
Cc: Kairui Song &lt;kasong@tencent.com&gt;
Cc: Kees Cook &lt;kees@kernel.org&gt;
Cc: Kemeng Shi &lt;shikemeng@huaweicloud.com&gt;
Cc: Lance Yang &lt;lance.yang@linux.dev&gt;
Cc: Liam R. Howlett &lt;liam@infradead.org&gt;
Cc: Liviu Dudau &lt;liviu.dudau@arm.com&gt;
Cc: Maarten Lankhorst &lt;maarten.lankhorst@linux.intel.com&gt;
Cc: Marc Rutland &lt;mark.rutland@arm.com&gt;
Cc: "Masami Hiramatsu (Google)" &lt;mhiramat@kernel.org&gt;
Cc: Matthew Auld &lt;matthew.auld@intel.com&gt;
Cc: Matthew Brost &lt;matthew.brost@intel.com&gt;
Cc: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Cc: Maxime Ripard &lt;mripard@kernel.org&gt;
Cc: Miaohe Lin &lt;linmiaohe@huawei.com&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Mike Rapoport &lt;rppt@kernel.org&gt;
Cc: Muchun Song &lt;muchun.song@linux.dev&gt;
Cc: Namhyung kim &lt;namhyung@kernel.org&gt;
Cc: Naoya Horiguchi &lt;nao.horiguchi@gmail.com&gt;
Cc: Nhat Pham &lt;nphamcs@gmail.com&gt;
Cc: Nico Pache &lt;npache@redhat.com&gt;
Cc: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: Oscar Salvador &lt;osalvador@suse.de&gt;
Cc: Pedro Falcato &lt;pfalcato@suse.de&gt;
Cc: Peter Xu &lt;peterx@redhat.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Rakie Kim &lt;rakie.kim@sk.com&gt;
Cc: Rik van Riel &lt;riel@surriel.com&gt;
Cc: Rodrigo Vivi &lt;rodrigo.vivi@intel.com&gt;
Cc: Ryan Roberts &lt;ryan.roberts@arm.com&gt;
Cc: Steven Price &lt;steven.price@arm.com&gt;
Cc: Suren Baghdasaryan &lt;surenb@google.com&gt;
Cc: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Cc: Thomas Hellström &lt;thomas.hellstrom@linux.intel.com&gt;
Cc: Thomas Zimemrmann &lt;tzimmermann@suse.de&gt;
Cc: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Cc: Vlastimil Babka &lt;vbabka@kernel.org&gt;
Cc: xu xin &lt;xu.xin16@zte.com.cn&gt;
Cc: Zi Yan &lt;ziy@nvidia.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tools/testing/vma: add tests for copy_vma() self-merge</title>
<updated>2026-08-25T01:42:51+00:00</updated>
<author>
<name>Lorenzo Stoakes (ARM)</name>
<email>ljs@kernel.org</email>
</author>
<published>2026-08-13T17:32:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=746b9e0a4777e8e883d70b4292a6c3d8c435712c'/>
<id>746b9e0a4777e8e883d70b4292a6c3d8c435712c</id>
<content type='text'>
Assert that a VMA can be moved backwards, forwards and between a preceding
VMA and its old self.

In the cases in which the VMA merges only with itself expect that to be
achieved by expanding its old self, so assert that these function
correctly.

However in the case of a merge between a preceding VMA and itself the
original VMA is removed, so assert that the preceding VMA replaces the one
passed in as vmap and the merge is as expected.

Link: https://lore.kernel.org/20260813-b4-scalable-cow-virt-pgoff-v5-8-c21581c0c3c8@kernel.org
Signed-off-by: Lorenzo Stoakes (ARM) &lt;ljs@kernel.org&gt;
Acked-by: David Hildenbrand (Arm) &lt;david@kernel.org&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Alexander Deucher &lt;alexander.deucher@amd.com&gt;
Cc: Alexander Gordeev &lt;agordeev@linux.ibm.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Alistair Popple &lt;apopple@nvidia.com&gt;
Cc: Arnaldo Carvalho de Melo &lt;acme@kernel.org&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Baolin Wang &lt;baolin.wang@linux.alibaba.com&gt;
Cc: Baoquan He &lt;baoquan.he@linux.dev&gt;
Cc: Barry Song &lt;baohua@kernel.org&gt;
Cc: Boris Brezillon &lt;boris.brezillon@collabora.com&gt;
Cc: Byungchul Park &lt;byungchul@sk.com&gt;
Cc: Chengming Zhou &lt;chengming.zhou@linux.dev&gt;
Cc: Chris Li &lt;chrisl@kernel.org&gt;
Cc: Christan König &lt;christian.koenig@amd.com&gt;
Cc: Christian Borntraeger &lt;borntraeger@linux.ibm.com&gt;
Cc: Claudio Imbrenda &lt;imbrenda@linux.ibm.com&gt;
Cc: Dave Airlie &lt;airlied@gmail.com&gt;
Cc: Dev Jain &lt;dev.jain@arm.com&gt;
Cc: Gerald Schaefer &lt;gerald.schaefer@linux.ibm.com&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: Gregory Price (Meta) &lt;gourry@gourry.net&gt;
Cc: Harry Yoo &lt;harry@kernel.org&gt;
Cc: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Cc: Huang Ray &lt;Ray.Huang@amd.com&gt;
Cc: "Huang, Ying" &lt;ying.huang@linux.alibaba.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: James Clark &lt;james.clark@linaro.org&gt;
Cc: Jan Kara &lt;jack@suse.cz&gt;
Cc: Jann Horn &lt;jannh@google.com&gt;
Cc: Janosch Frank &lt;frankja@linux.ibm.com&gt;
Cc: Jason Gunthorpe &lt;jgg@ziepe.ca&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: John Hubbard &lt;jhubbard@nvidia.com&gt;
Cc: Joshua Hahn &lt;joshua.hahnjy@gmail.com&gt;
Cc: Kairui Song &lt;kasong@tencent.com&gt;
Cc: Kees Cook &lt;kees@kernel.org&gt;
Cc: Kemeng Shi &lt;shikemeng@huaweicloud.com&gt;
Cc: Lance Yang &lt;lance.yang@linux.dev&gt;
Cc: Liam R. Howlett &lt;liam@infradead.org&gt;
Cc: Liviu Dudau &lt;liviu.dudau@arm.com&gt;
Cc: Maarten Lankhorst &lt;maarten.lankhorst@linux.intel.com&gt;
Cc: Marc Rutland &lt;mark.rutland@arm.com&gt;
Cc: "Masami Hiramatsu (Google)" &lt;mhiramat@kernel.org&gt;
Cc: Matthew Auld &lt;matthew.auld@intel.com&gt;
Cc: Matthew Brost &lt;matthew.brost@intel.com&gt;
Cc: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Cc: Maxime Ripard &lt;mripard@kernel.org&gt;
Cc: Miaohe Lin &lt;linmiaohe@huawei.com&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Mike Rapoport &lt;rppt@kernel.org&gt;
Cc: Muchun Song &lt;muchun.song@linux.dev&gt;
Cc: Namhyung kim &lt;namhyung@kernel.org&gt;
Cc: Naoya Horiguchi &lt;nao.horiguchi@gmail.com&gt;
Cc: Nhat Pham &lt;nphamcs@gmail.com&gt;
Cc: Nico Pache &lt;npache@redhat.com&gt;
Cc: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: Oscar Salvador &lt;osalvador@suse.de&gt;
Cc: Pedro Falcato &lt;pfalcato@suse.de&gt;
Cc: Peter Xu &lt;peterx@redhat.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Rakie Kim &lt;rakie.kim@sk.com&gt;
Cc: Rik van Riel &lt;riel@surriel.com&gt;
Cc: Rodrigo Vivi &lt;rodrigo.vivi@intel.com&gt;
Cc: Ryan Roberts &lt;ryan.roberts@arm.com&gt;
Cc: Steven Price &lt;steven.price@arm.com&gt;
Cc: Suren Baghdasaryan &lt;surenb@google.com&gt;
Cc: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Cc: Thomas Hellström &lt;thomas.hellstrom@linux.intel.com&gt;
Cc: Thomas Zimemrmann &lt;tzimmermann@suse.de&gt;
Cc: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Cc: Vlastimil Babka &lt;vbabka@kernel.org&gt;
Cc: xu xin &lt;xu.xin16@zte.com.cn&gt;
Cc: Zi Yan &lt;ziy@nvidia.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Assert that a VMA can be moved backwards, forwards and between a preceding
VMA and its old self.

In the cases in which the VMA merges only with itself expect that to be
achieved by expanding its old self, so assert that these function
correctly.

However in the case of a merge between a preceding VMA and itself the
original VMA is removed, so assert that the preceding VMA replaces the one
passed in as vmap and the merge is as expected.

Link: https://lore.kernel.org/20260813-b4-scalable-cow-virt-pgoff-v5-8-c21581c0c3c8@kernel.org
Signed-off-by: Lorenzo Stoakes (ARM) &lt;ljs@kernel.org&gt;
Acked-by: David Hildenbrand (Arm) &lt;david@kernel.org&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Alexander Deucher &lt;alexander.deucher@amd.com&gt;
Cc: Alexander Gordeev &lt;agordeev@linux.ibm.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Alistair Popple &lt;apopple@nvidia.com&gt;
Cc: Arnaldo Carvalho de Melo &lt;acme@kernel.org&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Baolin Wang &lt;baolin.wang@linux.alibaba.com&gt;
Cc: Baoquan He &lt;baoquan.he@linux.dev&gt;
Cc: Barry Song &lt;baohua@kernel.org&gt;
Cc: Boris Brezillon &lt;boris.brezillon@collabora.com&gt;
Cc: Byungchul Park &lt;byungchul@sk.com&gt;
Cc: Chengming Zhou &lt;chengming.zhou@linux.dev&gt;
Cc: Chris Li &lt;chrisl@kernel.org&gt;
Cc: Christan König &lt;christian.koenig@amd.com&gt;
Cc: Christian Borntraeger &lt;borntraeger@linux.ibm.com&gt;
Cc: Claudio Imbrenda &lt;imbrenda@linux.ibm.com&gt;
Cc: Dave Airlie &lt;airlied@gmail.com&gt;
Cc: Dev Jain &lt;dev.jain@arm.com&gt;
Cc: Gerald Schaefer &lt;gerald.schaefer@linux.ibm.com&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: Gregory Price (Meta) &lt;gourry@gourry.net&gt;
Cc: Harry Yoo &lt;harry@kernel.org&gt;
Cc: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Cc: Huang Ray &lt;Ray.Huang@amd.com&gt;
Cc: "Huang, Ying" &lt;ying.huang@linux.alibaba.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: James Clark &lt;james.clark@linaro.org&gt;
Cc: Jan Kara &lt;jack@suse.cz&gt;
Cc: Jann Horn &lt;jannh@google.com&gt;
Cc: Janosch Frank &lt;frankja@linux.ibm.com&gt;
Cc: Jason Gunthorpe &lt;jgg@ziepe.ca&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: John Hubbard &lt;jhubbard@nvidia.com&gt;
Cc: Joshua Hahn &lt;joshua.hahnjy@gmail.com&gt;
Cc: Kairui Song &lt;kasong@tencent.com&gt;
Cc: Kees Cook &lt;kees@kernel.org&gt;
Cc: Kemeng Shi &lt;shikemeng@huaweicloud.com&gt;
Cc: Lance Yang &lt;lance.yang@linux.dev&gt;
Cc: Liam R. Howlett &lt;liam@infradead.org&gt;
Cc: Liviu Dudau &lt;liviu.dudau@arm.com&gt;
Cc: Maarten Lankhorst &lt;maarten.lankhorst@linux.intel.com&gt;
Cc: Marc Rutland &lt;mark.rutland@arm.com&gt;
Cc: "Masami Hiramatsu (Google)" &lt;mhiramat@kernel.org&gt;
Cc: Matthew Auld &lt;matthew.auld@intel.com&gt;
Cc: Matthew Brost &lt;matthew.brost@intel.com&gt;
Cc: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Cc: Maxime Ripard &lt;mripard@kernel.org&gt;
Cc: Miaohe Lin &lt;linmiaohe@huawei.com&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Mike Rapoport &lt;rppt@kernel.org&gt;
Cc: Muchun Song &lt;muchun.song@linux.dev&gt;
Cc: Namhyung kim &lt;namhyung@kernel.org&gt;
Cc: Naoya Horiguchi &lt;nao.horiguchi@gmail.com&gt;
Cc: Nhat Pham &lt;nphamcs@gmail.com&gt;
Cc: Nico Pache &lt;npache@redhat.com&gt;
Cc: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: Oscar Salvador &lt;osalvador@suse.de&gt;
Cc: Pedro Falcato &lt;pfalcato@suse.de&gt;
Cc: Peter Xu &lt;peterx@redhat.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Rakie Kim &lt;rakie.kim@sk.com&gt;
Cc: Rik van Riel &lt;riel@surriel.com&gt;
Cc: Rodrigo Vivi &lt;rodrigo.vivi@intel.com&gt;
Cc: Ryan Roberts &lt;ryan.roberts@arm.com&gt;
Cc: Steven Price &lt;steven.price@arm.com&gt;
Cc: Suren Baghdasaryan &lt;surenb@google.com&gt;
Cc: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Cc: Thomas Hellström &lt;thomas.hellstrom@linux.intel.com&gt;
Cc: Thomas Zimemrmann &lt;tzimmermann@suse.de&gt;
Cc: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Cc: Vlastimil Babka &lt;vbabka@kernel.org&gt;
Cc: xu xin &lt;xu.xin16@zte.com.cn&gt;
Cc: Zi Yan &lt;ziy@nvidia.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm/vma: update vma_shrink() to not pass start, pgoff parameters</title>
<updated>2026-08-05T02:19:03+00:00</updated>
<author>
<name>Lorenzo Stoakes</name>
<email>ljs@kernel.org</email>
</author>
<published>2026-07-10T20:17:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=6387563e6ecdbd81d138525214475e66967801ab'/>
<id>6387563e6ecdbd81d138525214475e66967801ab</id>
<content type='text'>
vma_shrink() is only used by relocate_vma_down() to shrink the tail of a
VMA. Therefore neither the start nor the pgoff parameters make any sense.

It seemed we were passing the pgoff parameter solely to satisfy
vma_set_range()'s requirement for pgoff being specified.

Since vma_set_range() is now isolated to vma.c, we can simply introduce
__vma_set_range() which sets only vma-&gt;vm_[start, end], and invoke this
instead, removing start and pgoff from vma_shrink() altogether.

No functional change intended.

Link: https://lore.kernel.org/20260710-b4-pre-scalable-cow-v2-26-2a5aa403d977@kernel.org
Signed-off-by: Lorenzo Stoakes &lt;ljs@kernel.org&gt;
Reviewed-by: Pedro Falcato &lt;pfalcato@suse.de&gt;
Reviewed-by: Gregory Price &lt;gourry@gourry.net&gt;
Reviewed-by: Vlastimil Babka (SUSE) &lt;vbabka@kernel.org&gt;
Cc: Ackerley Tng &lt;ackerleytng@google.com&gt;
Cc: David Hildenbrand (Arm) &lt;david@kernel.org&gt;
Cc: Kai Huang &lt;kai.huang@intel.com&gt;
Cc: Marek Szyprowski &lt;m.szyprowski@samsung.com&gt;
Cc: SJ Park &lt;sj@kernel.org&gt;
Cc: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Cc: Liam R. Howlett (Oracle) &lt;liam@infradead.org&gt;
Cc: Zi Yan &lt;ziy@nvidia.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
vma_shrink() is only used by relocate_vma_down() to shrink the tail of a
VMA. Therefore neither the start nor the pgoff parameters make any sense.

It seemed we were passing the pgoff parameter solely to satisfy
vma_set_range()'s requirement for pgoff being specified.

Since vma_set_range() is now isolated to vma.c, we can simply introduce
__vma_set_range() which sets only vma-&gt;vm_[start, end], and invoke this
instead, removing start and pgoff from vma_shrink() altogether.

No functional change intended.

Link: https://lore.kernel.org/20260710-b4-pre-scalable-cow-v2-26-2a5aa403d977@kernel.org
Signed-off-by: Lorenzo Stoakes &lt;ljs@kernel.org&gt;
Reviewed-by: Pedro Falcato &lt;pfalcato@suse.de&gt;
Reviewed-by: Gregory Price &lt;gourry@gourry.net&gt;
Reviewed-by: Vlastimil Babka (SUSE) &lt;vbabka@kernel.org&gt;
Cc: Ackerley Tng &lt;ackerleytng@google.com&gt;
Cc: David Hildenbrand (Arm) &lt;david@kernel.org&gt;
Cc: Kai Huang &lt;kai.huang@intel.com&gt;
Cc: Marek Szyprowski &lt;m.szyprowski@samsung.com&gt;
Cc: SJ Park &lt;sj@kernel.org&gt;
Cc: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Cc: Liam R. Howlett (Oracle) &lt;liam@infradead.org&gt;
Cc: Zi Yan &lt;ziy@nvidia.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tools/testing/vma: use vma_start_pgoff() in merge tests</title>
<updated>2026-08-05T02:18:56+00:00</updated>
<author>
<name>Lorenzo Stoakes</name>
<email>ljs@kernel.org</email>
</author>
<published>2026-07-10T20:16:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=3542bc07f44fd80689c6a7bc0363f02707f194c9'/>
<id>3542bc07f44fd80689c6a7bc0363f02707f194c9</id>
<content type='text'>
Now we have the vma_start_pgoff() helper, update the merge tests to make
use of it for consistency.

No functional change intended.

Link: https://lore.kernel.org/20260710-b4-pre-scalable-cow-v2-3-2a5aa403d977@kernel.org
Signed-off-by: Lorenzo Stoakes &lt;ljs@kernel.org&gt;
Reviewed-by: Pedro Falcato &lt;pfalcato@suse.de&gt;
Reviewed-by: Gregory Price &lt;gourry@gourry.net&gt;
Reviewed-by: Vlastimil Babka (SUSE) &lt;vbabka@kernel.org&gt;
Reviewed-by: Liam R. Howlett (Oracle) &lt;liam@infradead.org&gt;
Reviewed-by: Zi Yan &lt;ziy@nvidia.com&gt;
Cc: Ackerley Tng &lt;ackerleytng@google.com&gt;
Cc: David Hildenbrand (Arm) &lt;david@kernel.org&gt;
Cc: Kai Huang &lt;kai.huang@intel.com&gt;
Cc: Marek Szyprowski &lt;m.szyprowski@samsung.com&gt;
Cc: SJ Park &lt;sj@kernel.org&gt;
Cc: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Now we have the vma_start_pgoff() helper, update the merge tests to make
use of it for consistency.

No functional change intended.

Link: https://lore.kernel.org/20260710-b4-pre-scalable-cow-v2-3-2a5aa403d977@kernel.org
Signed-off-by: Lorenzo Stoakes &lt;ljs@kernel.org&gt;
Reviewed-by: Pedro Falcato &lt;pfalcato@suse.de&gt;
Reviewed-by: Gregory Price &lt;gourry@gourry.net&gt;
Reviewed-by: Vlastimil Babka (SUSE) &lt;vbabka@kernel.org&gt;
Reviewed-by: Liam R. Howlett (Oracle) &lt;liam@infradead.org&gt;
Reviewed-by: Zi Yan &lt;ziy@nvidia.com&gt;
Cc: Ackerley Tng &lt;ackerleytng@google.com&gt;
Cc: David Hildenbrand (Arm) &lt;david@kernel.org&gt;
Cc: Kai Huang &lt;kai.huang@intel.com&gt;
Cc: Marek Szyprowski &lt;m.szyprowski@samsung.com&gt;
Cc: SJ Park &lt;sj@kernel.org&gt;
Cc: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm/vma: convert __mmap_region() to use vma_flags_t</title>
<updated>2026-04-05T20:53:41+00:00</updated>
<author>
<name>Lorenzo Stoakes (Oracle)</name>
<email>ljs@kernel.org</email>
</author>
<published>2026-03-20T19:38:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=90cb921c4d7bf92854344d3e76561f48784c613e'/>
<id>90cb921c4d7bf92854344d3e76561f48784c613e</id>
<content type='text'>
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) &lt;ljs@kernel.org&gt;
Acked-by: Vlastimil Babka (SUSE) &lt;vbabka@kernel.org&gt;
Cc: Albert Ou &lt;aou@eecs.berkeley.edu&gt;
Cc: Alexander Gordeev &lt;agordeev@linux.ibm.com&gt;
Cc: Alexandre Ghiti &lt;alex@ghiti.fr&gt;
Cc: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Cc: Anton Ivanov &lt;anton.ivanov@cambridgegreys.com&gt;
Cc: "Borislav Petkov (AMD)" &lt;bp@alien8.de&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Chengming Zhou &lt;chengming.zhou@linux.dev&gt;
Cc: Christian Borntraeger &lt;borntraeger@linux.ibm.com&gt;
Cc: Christian Brauner &lt;brauner@kernel.org&gt;
Cc: David Hildenbrand &lt;david@kernel.org&gt;
Cc: Dinh Nguyen &lt;dinguyen@kernel.org&gt;
Cc: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Cc: Huacai Chen &lt;chenhuacai@kernel.org&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Jan Kara &lt;jack@suse.cz&gt;
Cc: Jann Horn &lt;jannh@google.com&gt;
Cc: Johannes Berg &lt;johannes@sipsolutions.net&gt;
Cc: Kees Cook &lt;kees@kernel.org&gt;
Cc: Liam Howlett &lt;liam.howlett@oracle.com&gt;
Cc: Madhavan Srinivasan &lt;maddy@linux.ibm.com&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Mike Rapoport &lt;rppt@kernel.org&gt;
Cc: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Cc: Ondrej Mosnacek &lt;omosnace@redhat.com&gt;
Cc: Palmer Dabbelt &lt;palmer@dabbelt.com&gt;
Cc: Paul Moore &lt;paul@paul-moore.com&gt;
Cc: Pedro Falcato &lt;pfalcato@suse.de&gt;
Cc: Richard Weinberger &lt;richard@nod.at&gt;
Cc: Russell King &lt;linux@armlinux.org.uk&gt;
Cc: Stephen Smalley &lt;stephen.smalley.work@gmail.com&gt;
Cc: Suren Baghdasaryan &lt;surenb@google.com&gt;
Cc: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Cc: Thomas Bogendoerfer &lt;tsbogend@alpha.franken.de&gt;
Cc: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Cc: Vineet Gupta &lt;vgupta@kernel.org&gt;
Cc: WANG Xuerui &lt;kernel@xen0n.name&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Cc: xu xin &lt;xu.xin16@zte.com.cn&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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) &lt;ljs@kernel.org&gt;
Acked-by: Vlastimil Babka (SUSE) &lt;vbabka@kernel.org&gt;
Cc: Albert Ou &lt;aou@eecs.berkeley.edu&gt;
Cc: Alexander Gordeev &lt;agordeev@linux.ibm.com&gt;
Cc: Alexandre Ghiti &lt;alex@ghiti.fr&gt;
Cc: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Cc: Anton Ivanov &lt;anton.ivanov@cambridgegreys.com&gt;
Cc: "Borislav Petkov (AMD)" &lt;bp@alien8.de&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Chengming Zhou &lt;chengming.zhou@linux.dev&gt;
Cc: Christian Borntraeger &lt;borntraeger@linux.ibm.com&gt;
Cc: Christian Brauner &lt;brauner@kernel.org&gt;
Cc: David Hildenbrand &lt;david@kernel.org&gt;
Cc: Dinh Nguyen &lt;dinguyen@kernel.org&gt;
Cc: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Cc: Huacai Chen &lt;chenhuacai@kernel.org&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Jan Kara &lt;jack@suse.cz&gt;
Cc: Jann Horn &lt;jannh@google.com&gt;
Cc: Johannes Berg &lt;johannes@sipsolutions.net&gt;
Cc: Kees Cook &lt;kees@kernel.org&gt;
Cc: Liam Howlett &lt;liam.howlett@oracle.com&gt;
Cc: Madhavan Srinivasan &lt;maddy@linux.ibm.com&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Mike Rapoport &lt;rppt@kernel.org&gt;
Cc: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Cc: Ondrej Mosnacek &lt;omosnace@redhat.com&gt;
Cc: Palmer Dabbelt &lt;palmer@dabbelt.com&gt;
Cc: Paul Moore &lt;paul@paul-moore.com&gt;
Cc: Pedro Falcato &lt;pfalcato@suse.de&gt;
Cc: Richard Weinberger &lt;richard@nod.at&gt;
Cc: Russell King &lt;linux@armlinux.org.uk&gt;
Cc: Stephen Smalley &lt;stephen.smalley.work@gmail.com&gt;
Cc: Suren Baghdasaryan &lt;surenb@google.com&gt;
Cc: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Cc: Thomas Bogendoerfer &lt;tsbogend@alpha.franken.de&gt;
Cc: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Cc: Vineet Gupta &lt;vgupta@kernel.org&gt;
Cc: WANG Xuerui &lt;kernel@xen0n.name&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Cc: xu xin &lt;xu.xin16@zte.com.cn&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
