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 751403B14AB for ; Sat, 3 Oct 2026 22:39:06 +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=1791067148; cv=none; b=ZygAsZTqtc0ZeuctRxIH/M7Ro47jopqA+o5cqoIwt3FuIe8ilVp9vbUkCLM0NCJJcZHD19Ont2lRk9eGzQ1DUBuOA+WX2TfyMa5dnFvOWFRXKiXDx4iqRiB+vyehZFQassWDEVUFDMZj+cAAm2Vkfy7SIH1ndQ71XB1uSmmsRAc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791067148; c=relaxed/simple; bh=DwpxhLk2VIbcxmgG3O/hFiHyDNZ+P2vsH5CO6WiKWH8=; h=Date:To:From:Subject:Message-Id; b=M3eyYSO54ff4mO7hMQbbvbu+A3eSIZ28++xdVRESWcJSjNlehUZopwttVjLKNuNZTl/ZZ95eTBCANirV6y1zRKe7vGTv754n+yLbVtNg2ByTPa0O2i4UgVGpyvqGHqbPKuxycIi0iX33gBmTsyGdalpvWr7qP1E0kzG8QAzn0/0= 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=R2VKKFz3; 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="R2VKKFz3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4A29E1F0089C; Sat, 3 Oct 2026 22:39:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1791067146; bh=x2UJP9JWSORWq1gJpugnfhZRFg+a3gKVMiRbwvN9E68=; h=Date:To:From:Subject; b=R2VKKFz3P48T8KAq/3vrdmgai4WaG28jpMM2kFWiJBO4b4MTE4AdUfh45NsORdJ8U Z7ew3jtlCetFOZG59VOtsVVXC2Hlth+ozVhCHbaFLtvXVEx7nyf6LnX9ARegu3WUrH x5hYvMLoQ5+LbtWb4yOxC9vM61FJAgnUZMWnV3VQ= Date: Sat, 03 Oct 2026 15:39:05 -0700 To: mm-commits@vger.kernel.org,ljs@kernel.org,akpm@linux-foundation.org From: Andrew Morton Subject: [to-be-updated] mm-vma-introduce-vma_is_persistent.patch removed from -mm tree Message-Id: <20261003223906.4A29E1F0089C@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: introduce vma[_flags]_is_persistent() has been removed from the -mm tree. Its filename was mm-vma-introduce-vma_is_persistent.patch This patch was dropped because an updated version will be issued ------------------------------------------------------ From: "Lorenzo Stoakes (ARM)" Subject: mm/vma: introduce vma[_flags]_is_persistent() Date: Thu, 17 Sep 2026 17:22:40 +0100 Introduce vma[_flags]_is_persistent() for the purposes of identifying mappings that are persistent in the sense that bytes to the mapping stay there, and bytes read from the mapping are the same unless changed by actions taken by userland. Kernel-owned mappings do not fall into this category, as their owner may change the contents without the user having initiated it, and nor of course does memory-mapped I/O. We exclude fixed mappings as these are singled out as being unmergeable and so cannot be guaranteed to persist user data. hugetlb mappings are fixed mappings, but their contents are entirely the user's, so they are explicitly carved out as persistent, as the MADV_DODUMP check already does. It excludes droppable mappings, which by their nature are ephemeral. Use this functionality to update the madvise MADV_DODUMP check to test for persistence rather than open-coding this. This replaces the VM_SPECIAL check which means it no longer checks for VMA_IO_BIT, however this is safe as we have established the invariant that only kernel-owned mappings may set VMA_IO_BIT, so we implicitly include these. No functional change intended. Link: https://lore.kernel.org/20260917-b4-mmap-prepare-vma-flag-sanify-v3-31-4583d8a23bca@kernel.org Signed-off-by: Lorenzo Stoakes (ARM) Signed-off-by: Andrew Morton Acked-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 | 44 +++++++++++++++++++++++++++++++++++++++++++ mm/madvise.c | 4 +-- 2 files changed, 46 insertions(+), 2 deletions(-) --- a/include/linux/mm.h~mm-vma-introduce-vma_is_persistent +++ a/include/linux/mm.h @@ -1743,6 +1743,50 @@ static inline bool vma_can_merge(const s } /** + * vma_flags_is_persistent() - Do the specified VMA flags imply that the VMA + * contains persistent data? + * @flags: The VMA flags to test. + * + * Persistent in the sense that - if you write bytes to the mapping - do they + * stay written? + * + * If the kernel or a device could write to the memory independently of + * userland, or the kernel could arbitrarily discard it, then it is not + * persistent. + * + * Returns: true if the flags imply this VMA is persistent, otherwise false. + */ +static inline bool vma_flags_is_persistent(const vma_flags_t *flags) +{ + /* hugetlb is a fixed mapping, but its contents are the user's own. */ + if (vma_flags_is_hugetlb(flags)) + return true; + /* + * MMIO mappings may not store what is written and may be changed by the + * device. Kernel-owned and fixed mappings may be changed by their owner + * without the user having initiated it. + */ + if (vma_flags_is_kernel_owned(flags) || + vma_flags_is_fixed_mapping(flags)) + return false; + /* Droppable memory is discardable by definition. */ + return !vma_flags_test_single_mask(flags, VMA_DROPPABLE); +} + +/** + * vma_is_persistent() - Does the VMA contain persistent data? + * @vma: The VMA to test. + * + * See vma_flags_is_persistent() for details. + * + * Returns: true if the VMA is persistent, otherwise false. + */ +static inline bool vma_is_persistent(const struct vm_area_struct *vma) +{ + return vma_flags_is_persistent(&vma->flags); +} + +/** * vma_kernel_pagesize - Default page size granularity for this VMA. * @vma: The user mapping. * --- a/mm/madvise.c~mm-vma-introduce-vma_is_persistent +++ a/mm/madvise.c @@ -1585,8 +1585,8 @@ static int madvise_vma_behavior(struct m new_flags |= VM_DONTDUMP; break; case MADV_DODUMP: - if ((!vma_is_hugetlb(vma) && (new_flags & VM_SPECIAL)) || - (new_flags & VM_DROPPABLE)) + /* Non-persistent memory cannot be dumped. */ + if (!vma_is_persistent(vma)) return -EINVAL; new_flags &= ~VM_DONTDUMP; break; _ 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-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