kernel/linux.git/tools, branch v6.18.37

testing/selftests/mm: add soft-dirty merge self-test

2026-06-27T10:06:49+00:00

commit c7ba92bcfea34f6b4afc744c3b65c8f7420fefe0 upstream. Assert that we correctly merge VMAs containing VM_SOFTDIRTY flags now that we correctly handle these as sticky. In order to do so, we have to account for the fact the pagemap interface checks soft dirty PTEs and additionally that newly merged VMAs are marked VM_SOFTDIRTY. We do this by using use unfaulted anon VMAs, establishing one and clearing references on that one, before establishing another and merging the two before checking that soft-dirty is propagated as expected. We check that this functions correctly with mremap() and mprotect() as sample cases, because VMA merge of adjacent newly mapped VMAs will automatically be made soft-dirty due to existing logic which does so. We are therefore exercising other means of merging VMAs. Link: https://lkml.kernel.org/r/d5a0f735783fb4f30a604f570ede02ccc5e29be9.1763399675.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes Cc: Andrey Vagin Cc: David Hildenbrand (Red Hat) Cc: Jann Horn Cc: Liam Howlett Cc: Michal Hocko Cc: Mike Rapoport Cc: Pedro Falcato Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Cyrill Gorcunov Signed-off-by: Andrew Morton Signed-off-by: Ahmed Elaidy Signed-off-by: Greg Kroah-Hartman

mm: propagate VM_SOFTDIRTY on merge

2026-06-27T10:06:49+00:00

commit 6707915e030a3258868355f989b80140c1a45bbe upstream. Patch series "make VM_SOFTDIRTY a sticky VMA flag", v2. Currently we set VM_SOFTDIRTY when a new mapping is set up (whether by establishing a new VMA, or via merge) as implemented in __mmap_complete() and do_brk_flags(). However, when performing a merge of existing mappings such as when performing mprotect(), we may lose the VM_SOFTDIRTY flag. Now we have the concept of making VMA flags 'sticky', that is that they both don't prevent merge and, importantly, are propagated to merged VMAs, this seems a sensible alternative to the existing special-casing of VM_SOFTDIRTY. We additionally add a self-test that demonstrates that this logic behaves as expected. This patch (of 2): Currently we set VM_SOFTDIRTY when a new mapping is set up (whether by establishing a new VMA, or via merge) as implemented in __mmap_complete() and do_brk_flags(). However, when performing a merge of existing mappings such as when performing mprotect(), we may lose the VM_SOFTDIRTY flag. This is because currently we simply ignore VM_SOFTDIRTY for the purposes of merge, so one VMA may possess the flag and another not, and whichever happens to be the target VMA will be the one upon which the merge is performed which may or may not have VM_SOFTDIRTY set. Now we have the concept of 'sticky' VMA flags, let's make VM_SOFTDIRTY one which solves this issue. Additionally update VMA userland tests to propagate changes. [akpm@linux-foundation.org: update comments, per Lorenzo] Link: https://lkml.kernel.org/r/0019e0b8-ee1e-4359-b5ee-94225cbe5588@lucifer.local Link: https://lkml.kernel.org/r/cover.1763399675.git.ljs@kernel.org Link: https://lkml.kernel.org/r/955478b5170715c895d1ef3b7f68e0cd77f76868.1763399675.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes Suggested-by: Vlastimil Babka Acked-by: David Hildenbrand (Red Hat) Reviewed-by: Pedro Falcato Acked-by: Andrey Vagin Reviewed-by: Vlastimil Babka Acked-by: Cyrill Gorcunov Cc: Jann Horn Cc: Liam Howlett Cc: Michal Hocko Cc: Mike Rapoport Cc: Suren Baghdasaryan Signed-off-by: Andrew Morton Signed-off-by: Ahmed Elaidy Fixes: 34228d473efe ("mm: ignore VM_SOFTDIRTY on VMA merging") Signed-off-by: Greg Kroah-Hartman

mm: introduce copy-on-fork VMAs and make VM_MAYBE_GUARD one

2026-06-27T10:06:49+00:00

commit ab04b530e7e8bd5cf9fb0c1ad20e0deee8f569ec upstream. Gather all the VMA flags whose presence implies that page tables must be copied on fork into a single bitmap - VM_COPY_ON_FORK - and use this rather than specifying individual flags in vma_needs_copy(). We also add VM_MAYBE_GUARD to this list, as it being set on a VMA implies that there may be metadata contained in the page tables (that is - guard markers) which would will not and cannot be propagated upon fork. This was already being done manually previously in vma_needs_copy(), but this makes it very explicit, alongside VM_PFNMAP, VM_MIXEDMAP and VM_UFFD_WP all of which imply the same. Note that VM_STICKY flags ought generally to be marked VM_COPY_ON_FORK too - because equally a flag being VM_STICKY indicates that the VMA contains metadat that is not propagated by being faulted in - i.e. that the VMA metadata does not fully describe the VMA alone, and thus we must propagate whatever metadata there is on a fork. However, for maximum flexibility, we do not make this necessarily the case here. Link: https://lkml.kernel.org/r/5d41b24e7bc622cda0af92b6d558d7f4c0d1bc8c.1763460113.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes Reviewed-by: Pedro Falcato Reviewed-by: Vlastimil Babka Acked-by: David Hildenbrand (Red Hat) Cc: Andrei Vagin Cc: Baolin Wang Cc: Barry Song Cc: Dev Jain Cc: Jann Horn Cc: Jonathan Corbet Cc: Lance Yang Cc: Liam Howlett Cc: "Masami Hiramatsu (Google)" Cc: Mathieu Desnoyers Cc: Michal Hocko Cc: Mike Rapoport Cc: Nico Pache Cc: Ryan Roberts Cc: Steven Rostedt Cc: Suren Baghdasaryan Cc: Zi Yan Signed-off-by: Andrew Morton Signed-off-by: Ahmed Elaidy Signed-off-by: Greg Kroah-Hartman

mm: implement sticky VMA flags

2026-06-27T10:06:49+00:00

commit 64212ba02e66e705cabce188453ba4e61e9d7325 upstream. It is useful to be able to designate that certain flags are 'sticky', that is, if two VMAs are merged one with a flag of this nature and one without, the merged VMA sets this flag. As a result we ignore these flags for the purposes of determining VMA flag differences between VMAs being considered for merge. This patch therefore updates the VMA merge logic to perform this action, with flags possessing this property being described in the VM_STICKY bitmap. Those flags which ought to be ignored for the purposes of VMA merge are described in the VM_IGNORE_MERGE bitmap, which the VMA merge logic is also updated to use. As part of this change we place VM_SOFTDIRTY in VM_IGNORE_MERGE as it already had this behaviour, alongside VM_STICKY as sticky flags by implication must not disallow merge. Ultimately it seems that we should make VM_SOFTDIRTY a sticky flag in its own right, but this change is out of scope for this series. The only sticky flag designated as such is VM_MAYBE_GUARD, so as a result of this change, once the VMA flag is set upon guard region installation, VMAs with guard ranges will now not have their merge behaviour impacted as a result and can be freely merged with other VMAs without VM_MAYBE_GUARD set. Also update the comments for vma_modify_flags() to directly reference sticky flags now we have established the concept. We also update the VMA userland tests to account for the changes. Link: https://lkml.kernel.org/r/22ad5269f7669d62afb42ce0c79bad70b994c58d.1763460113.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes Reviewed-by: Pedro Falcato Reviewed-by: Vlastimil Babka Cc: Andrei Vagin Cc: Baolin Wang Cc: Barry Song Cc: David Hildenbrand (Red Hat) Cc: Dev Jain Cc: Jann Horn Cc: Jonathan Corbet Cc: Lance Yang Cc: Liam Howlett Cc: "Masami Hiramatsu (Google)" Cc: Mathieu Desnoyers Cc: Michal Hocko Cc: Mike Rapoport Cc: Nico Pache Cc: Ryan Roberts Cc: Steven Rostedt Cc: Suren Baghdasaryan Cc: Zi Yan Signed-off-by: Andrew Morton Signed-off-by: Ahmed Elaidy Signed-off-by: Greg Kroah-Hartman

mm: update vma_modify_flags() to handle residual flags, document

2026-06-27T10:06:49+00:00

commit 9119d6c2095bb20292cb9812dd70d37f17e3bd37 upstream. The vma_modify_*() family of functions each either perform splits, a merge or no changes at all in preparation for the requested modification to occur. When doing so for a VMA flags change, we currently don't account for any flags which may remain (for instance, VM_SOFTDIRTY) despite the requested change in the case that a merge succeeded. This is made more important by subsequent patches which will introduce the concept of sticky VMA flags which rely on this behaviour. This patch fixes this by passing the VMA flags parameter as a pointer and updating it accordingly on merge and updating callers to accommodate for this. Additionally, while we are here, we add kdocs for each of the vma_modify_*() functions, as the fact that the requested modification is not performed is confusing so it is useful to make this abundantly clear. We also update the VMA userland tests to account for this change. Link: https://lkml.kernel.org/r/23b5b549b0eaefb2922625626e58c2a352f3e93c.1763460113.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes Reviewed-by: Pedro Falcato Reviewed-by: Vlastimil Babka Cc: Andrei Vagin Cc: Baolin Wang Cc: Barry Song Cc: David Hildenbrand (Red Hat) Cc: Dev Jain Cc: Jann Horn Cc: Jonathan Corbet Cc: Lance Yang Cc: Liam Howlett Cc: "Masami Hiramatsu (Google)" Cc: Mathieu Desnoyers Cc: Michal Hocko Cc: Mike Rapoport Cc: Nico Pache Cc: Ryan Roberts Cc: Steven Rostedt Cc: Suren Baghdasaryan Cc: Zi Yan Signed-off-by: Andrew Morton Signed-off-by: Ahmed Elaidy Signed-off-by: Greg Kroah-Hartman

mm: introduce VM_MAYBE_GUARD and make visible in /proc/$pid/smaps

2026-06-27T10:06:48+00:00

commit 5dba5cc2e0ffa76f2f6c8922a04469dc9602c396 upstream. Patch series "introduce VM_MAYBE_GUARD and make it sticky", v4. Currently, guard regions are not visible to users except through /proc/$pid/pagemap, with no explicit visibility at the VMA level. This makes the feature less useful, as it isn't entirely apparent which VMAs may have these entries present, especially when performing actions which walk through memory regions such as those performed by CRIU. This series addresses this issue by introducing the VM_MAYBE_GUARD flag which fulfils this role, updating the smaps logic to display an entry for these. The semantics of this flag are that a guard region MAY be present if set (we cannot be sure, as we can't efficiently track whether an MADV_GUARD_REMOVE finally removes all the guard regions in a VMA) - but if not set the VMA definitely does NOT have any guard regions present. It's problematic to establish this flag without further action, because that means that VMAs with guard regions in them become non-mergeable with adjacent VMAs for no especially good reason. To work around this, this series also introduces the concept of 'sticky' VMA flags - that is flags which: a. if set in one VMA and not in another still permit those VMAs to be merged (if otherwise compatible). b. When they are merged, the resultant VMA must have the flag set. The VMA logic is updated to propagate these flags correctly. Additionally, VM_MAYBE_GUARD being an explicit VMA flag allows us to solve an issue with file-backed guard regions - previously these established an anon_vma object for file-backed mappings solely to have vma_needs_copy() correctly propagate guard region mappings to child processes. We introduce a new flag alias VM_COPY_ON_FORK (which currently only specifies VM_MAYBE_GUARD) and update vma_needs_copy() to check explicitly for this flag and to copy page tables if it is present, which resolves this issue. Additionally, we add the ability for allow-listed VMA flags to be atomically writable with only mmap/VMA read locks held. The only flag we allow so far is VM_MAYBE_GUARD, which we carefully ensure does not cause any races by being allowed to do so. This allows us to maintain guard region installation as a read-locked operation and not endure the overhead of obtaining a write lock here. Finally we introduce extensive VMA userland tests to assert that the sticky VMA logic behaves correctly as well as guard region self tests to assert that smaps visibility is correctly implemented. This patch (of 9): Currently, if a user needs to determine if guard regions are present in a range, they have to scan all VMAs (or have knowledge of which ones might have guard regions). Since commit 8e2f2aeb8b48 ("fs/proc/task_mmu: add guard region bit to pagemap") and the related commit a516403787e0 ("fs/proc: extend the PAGEMAP_SCAN ioctl to report guard regions"), users can use either /proc/$pid/pagemap or the PAGEMAP_SCAN functionality to perform this operation at a virtual address level. This is not ideal, and it gives no visibility at a /proc/$pid/smaps level that guard regions exist in ranges. This patch remedies the situation by establishing a new VMA flag, VM_MAYBE_GUARD, to indicate that a VMA may contain guard regions (it is uncertain because we cannot reasonably determine whether a MADV_GUARD_REMOVE call has removed all of the guard regions in a VMA, and additionally VMAs may change across merge/split). We utilise 0x800 for this flag which makes it available to 32-bit architectures also, a flag that was previously used by VM_DENYWRITE, which was removed in commit 8d0920bde5eb ("mm: remove VM_DENYWRITE") and hasn't bee reused yet. We also update the smaps logic and documentation to identify these VMAs. Another major use of this functionality is that we can use it to identify that we ought to copy page tables on fork. We do not actually implement usage of this flag in mm/madvise.c yet as we need to allow some VMA flags to be applied atomically under mmap/VMA read lock in order to avoid the need to acquire a write lock for this purpose. Link: https://lkml.kernel.org/r/cover.1763460113.git.ljs@kernel.org Link: https://lkml.kernel.org/r/cf8ef821eba29b6c5b5e138fffe95d6dcabdedb9.1763460113.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes Reviewed-by: Pedro Falcato Reviewed-by: Vlastimil Babka Acked-by: David Hildenbrand (Red Hat) Reviewed-by: Lance Yang Cc: Andrei Vagin Cc: Baolin Wang Cc: Barry Song Cc: Dev Jain Cc: Jann Horn Cc: Jonathan Corbet Cc: Liam Howlett Cc: "Masami Hiramatsu (Google)" Cc: Mathieu Desnoyers Cc: Michal Hocko Cc: Mike Rapoport Cc: Nico Pache Cc: Ryan Roberts Cc: Steven Rostedt Cc: Suren Baghdasaryan Cc: Zi Yan Signed-off-by: Andrew Morton Signed-off-by: Ahmed Elaidy Signed-off-by: Greg Kroah-Hartman

selftests: mptcp: add test for extra_subflows underflow on userspace PM

2026-06-19T11:44:06+00:00

commit 06fd2bec7aebf393288e4b78924482fe170caabc upstream. Add a test to verify that when userspace PM fails to create a subflow (e.g. using an unreachable address), the extra_subflows counter is not decremented below zero. Fixes: 77e4b94a3de6 ("mptcp: update userspace pm infos") Cc: stable@vger.kernel.org Signed-off-by: Tao Cui Reviewed-by: Matthieu Baerts (NGI0) Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20260602-net-mptcp-misc-fixes-7-1-rc7-v2-6-856831229976@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

tracing/probes: Point the error offset correctly for eprobe argument error

2026-06-19T11:44:03+00:00

commit 85e0f27dd1396307913ffc5745b0c05137e9beac upstream. Fix to point the error offset correctly for eprobe argument error. In the cleanup commit 1b8b0cd754cd ("tracing/probes: Move event parameter fetching code to common parser"), due to incorrect backward compatibility aimed at conforming to the test specifications, the error location was set to 0 when a non-existent formal parameter was specified for Eprobe. However, this should be corrected in both the test and the implementation to point correct error position. Link: https://lore.kernel.org/all/177967567399.209006.1451571244515632097.stgit@devnote2/ Fixes: 1b8b0cd754cd ("tracing/probes: Move event parameter fetching code to common parser") Cc: stable@vger.kernel.org Signed-off-by: Masami Hiramatsu (Google) Reviewed-by: Steven Rostedt Signed-off-by: Greg Kroah-Hartman

verification/rvgen: Fix ltl2k writing True as a literal

2026-06-19T11:43:57+00:00

[ Upstream commit df996599cc69a9b74ff437c67751cf8a61f62e39 ] The rvgen parser for LTL stores literal true values in the python representation (capitalised True), this doesn't build in C. The Literal class should already handle this case but ASTNode skips its strigification method and converts the value (true/false) directly. Fix by delegating ASTNode stringification to the Literal and Variable classes instead of bypassing them. Fixes: 97ffa4ce6ab32 ("verification/rvgen: Add support for linear temporal logic") Reviewed-by: Nam Cao Link: https://lore.kernel.org/r/20260514152055.229162-8-gmonaco@redhat.com Signed-off-by: Gabriele Monaco Signed-off-by: Sasha Levin

verification/rvgen: Fix options shared among commands

2026-06-19T11:43:57+00:00

[ Upstream commit 5f845ad706c0b394ae274e9a930044f78bef782e ] After rvgen was refactored to use subparsers, the common options (-a and -D) were left in the main parser. This meant that they needed to be called /before/ the subcommand and using them without subcommand was allowed. This is not the original intent. rvgen -D "some description" container -n name Define the options as parent in the subparsers to allow them to be used from both subcommands together with other options. rvgen container -n name -D "some description" Fixes: 5270a0e3041c ("verification/dot2k: Replace is_container() hack with subparsers") Reviewed-by: Nam Cao Link: https://lore.kernel.org/r/20260514152055.229162-7-gmonaco@redhat.com Signed-off-by: Gabriele Monaco Signed-off-by: Sasha Levin