From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 93DB13A2E3F for ; Sat, 3 Oct 2026 22:38:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791067121; cv=none; b=tb1ubuQlEvEvCZDBk1FTs2NpvpH06CjClu4kS/N+6egjC+JmJeVbsaYOVK72KBxLd6ZxrGCgn1yEPCfBop9zJr/Nx+vs5qFNO8O8nnZ9Dk4943zXZ9ZvCjmj3+e0G+VYG4Q76NOBw0+4NYs8rwv4yO1Z+Zwla5uusGszloMXAa8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791067121; c=relaxed/simple; bh=vYROmt+gxZ/Aj+ToMLH5Ju0nsx4a1RpprFtbg4nv40c=; h=Date:To:From:Subject:Message-Id; b=fiBgdN2IW27rKJfqZ2PHpx4FRyxcW4LD1N3rRW+0z5OXv+Ndje9nMdFlJzvziht2vD7jOw/E7pHQMMXwwvF6Aql/lAuLH74ngSVJ4znga88H1+QaPp/GTBFBB+J0sYAtYM0kSERYNmu9J0iWDlDceKKFrRrQjrdIXQ2RxL4OKxQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=w2EhQ/qd; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="w2EhQ/qd" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6A9A41F0089D; Sat, 3 Oct 2026 22:38:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1791067119; bh=lrpXN+S7+7lBeBvOdyva9vLB/F3qaCfzKrz8wT4+ebY=; h=Date:To:From:Subject; b=w2EhQ/qdLwY/ObxWCTvneUYTC6JofDzlblWg4/FQi+GrAooZMuWgH0m59abx6ktQ6 d/tu4Uuu1UmPs/10z2y/JGkJT0bjHFPHbL7vLYhjt6ZaWqTv8+x0jeeG5t13CvBfQU ipzlO8wU86lbXOYnZO7hfw/jxzf6MTFcxmIHgSQY= Date: Sat, 03 Oct 2026 15:38:39 -0700 To: mm-commits@vger.kernel.org,ljs@kernel.org,akpm@linux-foundation.org From: Andrew Morton Subject: [to-be-updated] mm-vma-add-vma_is_kernel_owned-predicates.patch removed from -mm tree Message-Id: <20261003223839.6A9A41F0089D@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: mm/vma: add vma[_flags]_is_kernel_owned() predicates has been removed from the -mm tree. Its filename was mm-vma-add-vma_is_kernel_owned-predicates.patch This patch was dropped because an updated version will be issued ------------------------------------------------------ From: "Lorenzo Stoakes (ARM)" Subject: mm/vma: add vma[_flags]_is_kernel_owned() predicates Date: Thu, 17 Sep 2026 17:22:24 +0100 Rather than referring to VMA flags with uncertain meaning, add a new predicate that explicitly describes what possession of the VMA_PFNMAP_BIT or VMA_MIXEDMAP_BIT flags mean, and then refer to that function for determining VMA mergeability. Either flag means the contents of the mapping are owned by the kernel, usually a driver, rather than by the core mm: the memory may be MMIO, kernel-allocated pages or even ordinary pages the driver maps itself, but the core must not populate, reclaim, migrate, copy-on-write or merge the range on its own initiative. We initially also include VMA_IO_BIT here, as by implication, these must be kernel-owned. (mlock() also sets VMA_IO_BIT transiently on ordinary VMAs while locking them, which is addressed later in this series.) However the intent is to in future remove this, as no mapping should be marked as an I/O mapping without also being marked with VMA_PFNMAP_BIT. This forms the basis of further work intended to improve how we express VMA properties such as this. Also update the VMA userland tests to reflect the change. No functional change intended. Link: https://lore.kernel.org/20260917-b4-mmap-prepare-vma-flag-sanify-v3-15-4583d8a23bca@kernel.org Signed-off-by: Lorenzo Stoakes (ARM) Signed-off-by: Andrew Morton Reviewed-by: Zi Yan Cc: Albert Ou Cc: Alexander Gordeev Cc: Alexei Starovoitov Cc: Alistair Popple Cc: Al Viro Cc: Andreas Larsson Cc: Andrii Nakryiko Cc: "Aneesh Kumar K.V" Cc: Anup Patel Cc: Arnaldo Carvalho de Melo Cc: Arnd Bergmann Cc: Axel Rasmussen Cc: Baolin Wang Cc: Baoquan He Cc: Barry Song Cc: "Borislav Petkov (AMD)" Cc: Byungchul Park Cc: Catalin Marinas Cc: Chengming Zhou Cc: Chris Li Cc: Christian Borntraeger Cc: Christian Brauner Cc: Claudio Imbrenda Cc: Dave Airlie Cc: Dave Hansen Cc: David Hildenbrand Cc: David S. Miller Cc: Dennis Dalessandro Cc: Dev Jain Cc: Doug Gilbert Cc: Eduard Zingerman Cc: Emil Tsalapatis Cc: Gerald Schaefer Cc: Greg Kroah-Hartman Cc: Gregory Price Cc: Harry Yoo Cc: Heiko Carstens Cc: Helge Deller Cc: "Huang, Ying" Cc: Ingo Molnar Cc: James Bottomley Cc: Jan Kara Cc: Jann Horn Cc: Janosch Frank Cc: Jaroslav Kysela Cc: Jason Gunthorpe Cc: Jaya Kumar Cc: Johannes Weiner Cc: John Hubbard Cc: Jonathan Corbet Cc: Joshua Hahn Cc: Juri Lelli Cc: Kairui Song Cc: Kemeng Shi Cc: Kiryl Shutsemau Cc: Kumar Kartikeya Dwivedi Cc: Lance Yang Cc: Leon Romanovsky Cc: Liam R. Howlett Cc: Maarten Lankhorst Cc: Madhavan Srinivasan Cc: Marc Rutland Cc: Marc Zyngier Cc: "Masami Hiramatsu (Google)" Cc: Matthew Brost Cc: Matthew Wilcox (Oracle) Cc: Maxime Ripard Cc: Michal Hocko Cc: Michal Hocko Cc: Mike Rapoport Cc: Miklos Szeredi Cc: Muchun Song Cc: Namhyung kim Cc: Nhat Pham Cc: Nicholas Piggin Cc: Oleg Nesterov Cc: Oscar Salvador Cc: Palmer Dabbelt Cc: Paul Moore Cc: Pedro Falcato Cc: Peter Xu Cc: Peter Zijlstra Cc: Rakie Kim Cc: Rik van Riel Cc: Ryan Roberts Cc: Sebastian Reichel Cc: Shakeel Butt Cc: Stephen Smalley Cc: Suren Baghdasaryan Cc: Takashi Iwai (SUSE) Cc: Takashi Iwai Cc: Thomas Zimemrmann Cc: Vasily Gorbik Cc: Vincent Guittot Cc: Vlastimil Babka Cc: Wei Xu Cc: Will Deacon Cc: Yuanchu Xie --- include/linux/mm.h | 56 +++++++++++++++++++++++++++++- tools/testing/vma/include/dup.h | 29 +++++++++++++++ 2 files changed, 83 insertions(+), 2 deletions(-) --- a/include/linux/mm.h~mm-vma-add-vma_is_kernel_owned-predicates +++ a/include/linux/mm.h @@ -1614,6 +1614,44 @@ static inline bool vma_is_shared_maywrit } /** + * vma_flags_is_kernel_owned() - Do the specified VMA flags indicate that the + * contents of the VMA are owned by the kernel rather than the core mm? + * @flags: The VMA flags to test. + * + * A kernel-owned mapping is one whose contents are established and controlled + * by the kernel, typically a driver, rather than by the core mm's fault and + * rmap machinery. + * + * The mapping may be memory-mapped I/O, kernel-allocated pages or ordinary + * pages the owner has chosen to map itself (shmem via a PFN map, for instance). + * + * In all cases the core mm must not populate, reclaim, migrate, copy-on-write + * or merge it of its own accord. + * + * Pages mapped this way are not necessarily reference counted or map counted. + * + * Returns: true if the flags indicate a kernel-owned mapping. + */ +static inline bool vma_flags_is_kernel_owned(const vma_flags_t *flags) +{ + return vma_flags_test_any(flags, VMA_PFNMAP_BIT, VMA_MIXEDMAP_BIT, + VMA_IO_BIT); +} + +/** + * vma_is_kernel_owned() - Are the contents of @vma owned by the kernel? + * @vma: The VMA to test. + * + * See vma_flags_is_kernel_owned() for a description of this property. + * + * Returns: true if the VMA is kernel-owned. + */ +static inline bool vma_is_kernel_owned(const struct vm_area_struct *vma) +{ + return vma_flags_is_kernel_owned(&vma->flags); +} + +/** * vma_flags_can_merge() - Do the specified VMA flags permit the VMA to be * merged with another? * @flags: The VMA flags to test. @@ -1621,7 +1659,23 @@ static inline bool vma_is_shared_maywrit */ static inline bool vma_flags_can_merge(const vma_flags_t *flags) { - return !vma_flags_test_any_mask(flags, VMA_SPECIAL_FLAGS); + /* + * VMA merging assumes that a VMA's flags and fields completely describe + * its state. + * + * However, kernel-owned mappings may have established state upon mapping + * not embodied in any attribute of the VMA. + * + * Additionally, private (CoW) PFN maps encode the source PFN of the + * range in vma->vm_pgoff, which may otherwise cause spurious merges. + */ + if (vma_flags_is_kernel_owned(flags)) + return false; + /* VMA explicitly marked as being unmergeable. */ + if (vma_flags_test(flags, VMA_DONTEXPAND_BIT)) + return false; + + return true; } /** --- a/tools/testing/vma/include/dup.h~mm-vma-add-vma_is_kernel_owned-predicates +++ a/tools/testing/vma/include/dup.h @@ -1665,7 +1665,34 @@ static inline bool file_is_dev_zero(cons return file && file->f_op == &zero_fops; } +static inline bool vma_flags_is_kernel_owned(const vma_flags_t *flags) +{ + return vma_flags_test_any(flags, VMA_PFNMAP_BIT, VMA_MIXEDMAP_BIT, + VMA_IO_BIT); +} + +static inline bool vma_is_kernel_owned(const struct vm_area_struct *vma) +{ + return vma_flags_is_kernel_owned(&vma->flags); +} + static inline bool vma_flags_can_merge(const vma_flags_t *flags) { - return !vma_flags_test_any_mask(flags, VMA_SPECIAL_FLAGS); + /* + * VMA merging assumes that a VMA's flags and fields completely describe + * its state. + * + * However, kernel-owned mappings may have established state upon mapping + * not embodied in any attribute of the VMA. + * + * Additionally, private (CoW) PFN maps encode the source PFN of the + * range in vma->vm_pgoff, which may otherwise cause spurious merges. + */ + if (vma_flags_is_kernel_owned(flags)) + return false; + /* VMA explicitly marked as being unmergeable. */ + if (vma_flags_test(flags, VMA_DONTEXPAND_BIT)) + return false; + + return true; } _ Patches currently in -mm which might be from ljs@kernel.org are mm-mremap-fix-locked_vm-leak-from-mremap_dontunmap-self-merge.patch mm-mremap-fix-locked_vm-leak-by-splitting-vma-for-mremap_dontunmap.patch drivers-char-mem-mmap-readonly-map_shared-dev-zero-correctly.patch mm-vmpressure-remove-window-size-todo.patch tools-testing-selftests-mm-add-missing-gitignore-entries.patch mm-move-drivers-char-memc-to-mm-char-memc.patch mm-implement-file_is_dev_zero-to-uniquely-identify-dev-zero.patch mm-vma-only-permit-map_private-dev-zero-to-be-mapped-anonymous.patch mm-vma-make-map_private-mapped-dev-zero-mappings-truly-anonymous.patch tools-testing-vma-add-test-to-assert-map_private-dev-zero-is-anon.patch tools-testing-selftests-mm-add-map_private-dev-zero-merge-tests.patch mm-madvise-swap-in-cowd-map_private-file-mappings-on-madv_willneed.patch mm-khugepaged-deposit-a-newly-allocated-page-table-on-collapse.patch mm-enable-mmu_gather_rcu_table_free-for-most-2-level-architectures.patch mm-enable-mmu_gather_rcu_table_free-for-mmu-riscv.patch mm-enable-mmu_gather_rcu_table_free-for-mmu-arm.patch mm-enable-mmu_gather_rcu_table_free-for-arc-microblaze-xtensa.patch mm-enable-mmu_gather_rcu_table_free-for-sparc64.patch mm-enable-mmu_gather_rcu_table_free-for-m68k-coldfire.patch mm-enable-mmu_gather_rcu_table_free-for-sh-x2.patch mm-enable-mmu_gather_rcu_table_free-for-m68k-motorola.patch mm-enable-mmu_gather_rcu_table_free-for-sparc32.patch mm-userland-pgtable-freeing-is-rcu-safe-now-remove-leftover-bits.patch mm-change-the-contract-for-free_pgtables-update-docs.patch mm-vma-only-allow-mmap-to-clear-vma_maywrite_bit-if-kernel-owned.patch mm-vma-add-and-use-vma__is_fixed_mapping.patch scsi-sg-convert-mmap-hook-to-mmap_prepare-and-rework.patch fbdev-defio-assert-fbinfo_virtfb-drop-vm_io-add-vm_mixedmap.patch hsi-cmt_speech-convert-mmap-hook-to-mmap_prepare-refactor.patch mm-gup-error-out-early-on-vma_mayread_bit-vmas.patch uprobes-remove-vm_io-set-vm_mixedmap-for-mapped-kernel-pages.patch mm-mlock-clear-vma_locked_mask-over-mmap-callback.patch mm-mlock-eliminate-weird-vma_io_bit-abuse-and-simplify.patch mm-vma-enforce-that-only-kernel-owned-mappings-may-set-vma_io_bit.patch mm-remove-vma_io_bit-check-in-vma_is_kernel_owned.patch mm-remove-hugetlb_inlineh.patch mm-rename-is_vm_hugetlb_page-to-vma_is_hugetlb.patch mm-drop-some-redundant-checks-around-hugetlb-vmas.patch mm-madvise-update-is_valid_guard_vma-to-use-vma_can_merge.patch mm-vma-introduce-vma_is_persistent.patch mm-uffd-use-predicates-for-userfaultfd-checks.patch mm-madvise-use-predicates-for-madvise-madv_dofork.patch mm-eliminate-vma_special_flags-usage-when-hugetlb-explicitly-tested.patch mm-eliminate-vma_special_flags-check-in-lru_gen_look_around.patch mm-avoid-use-of-vma_special_flags-in-migrate_vma_setup.patch mm-eliminate-vm_special-vma_special_flags.patch fuse-dax-do-not-set-vm_mixedmap.patch mm-huge_memory-remove-vma_is_special_huge.patch mm-vma-introduce-and-use-vma_can_gup.patch mm-vma-const-ify-vma_assert_stabilised-and-associated-functions.patch mm-implement-and-use-vma_has_anon_rmap-silence-kcsan.patch mm-update-comments-to-refer-to-anon-rmap-rather-than-anon_vma.patch mm-vma-dont-remove-vma-from-rmap-if-pgoff-unchanged.patch