From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792781045; b=dieaLxxt95PeoZf3Ch4AmnU2lci4k2tB8YoLE3fVvCESQFQBYZUr5JInAR6U2QoeW4h3 TX4mM/HKlt+3hwIBJ1jqusxSGOmq1iKuPwXU34Esqy6rcICNoewdXrUF54ItG5In2f228 pi7zY2K1Ov9lUi/dqHHG1QScGzo/6uFL8SVoHh8og5J5z/GaUZ2sdC8H+YZPbezpuYmBk eFgavxT/ytTfOSPxVyitA2Fd7A/kmn2/cfP/spM6ReyizpmIdMHAWv/Z2oI/nPjndpPXc d37Lpx3ft0yEONP2StK1eNDQEF33rNzJx+nNmGYYh5vo/GT8ka2w9myRSFfetL1OhcQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792781045; h=Received:DKIM-Signature:Date:To:From:Subject:Message-Id; bh=g5A1ri2GF8L9E68ZWCDKheCuHTXXyMzXD+47Nx1Mk0s=; b=dW0SHjzLA0sGsN3UO+bIv8Blof2U2O3h0qpWh2LFK2cl8MgTdPLaacy0DRPB/6RtYl5/ eZqKweO23gHk67ZCiQT7hmneSV5105d3ZszHsdQLUkUghiu6PM02Dv0iFLqQ8M4XIomDG WHFvdkZ/qGdq16Xv2WG3delZJmD1NiJ86sQFxeIfK1e2nqPc7QDi2vUr1Nmgs9YEBYx52 LPrRztSfEUIYzgcXZ78vc6ABtMVtk87ekG/vAbF9KurPAR2N8+ZXE6jk9XRIQhWD0bxNC RbH19xQpJeWp8lgiPrK0xy4SDviMpbQ0Ln//gLHpX7T7Lz4PTE24qBxDLu7n98H+UWw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linux-foundation.org header.i=@linux-foundation.org header.a=rsa-sha256 header.s=korg header.b="X+/iGQYy"; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 30AFC606A325; Fri, 23 Oct 2026 18:44:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux-foundation.org header.i=@linux-foundation.org header.a=rsa-sha256 header.s=korg header.b=X+/iGQYy Received: by smtp.kernel.org (Postfix) with ESMTPSA id CAA381F01825; Fri, 23 Oct 2026 18:44:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1792781044; bh=g5A1ri2GF8L9E68ZWCDKheCuHTXXyMzXD+47Nx1Mk0s=; h=Date:To:From:Subject; b=X+/iGQYyjOKoeFfE/tnGYUTonb5qKY5Lu94XURyjejnCreuIR6tuQp3berqM+iwQX WySzh/wLUYA9NNtNo20HVql4OCe8IzsM6ZvikbEVXoBWlrtCMbt5AXv6KkjM7EfFbP yOLO+v4oasoXLShxNbw3Y5bBP0c5cjOs7JlL8XPA= Date: Fri, 23 Oct 2026 11:44:04 -0700 To: mm-commits@vger.kernel.org,vbabka@kernel.org,surenb@google.com,stable@vger.kernel.org,sj@kernel.org,rppt@kernel.org,pfalcato@suse.de,mhocko@suse.com,ljs@kernel.org,liam@infradead.org,kees@kernel.org,jannh@google.com,dave@stgolabs.net,ccross@google.com,david@kernel.org,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-madvise-preserve-vma_softdirty_bit-when-changing-anonymous-names.patch added to mm-unstable branch Message-Id: <20261023184404.CAA381F01825@smtp.kernel.org> X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list The patch titled Subject: mm/madvise: preserve VMA_SOFTDIRTY_BIT when changing anonymous names has been added to the -mm mm-unstable branch. Its filename is mm-madvise-preserve-vma_softdirty_bit-when-changing-anonymous-names.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-madvise-preserve-vma_softdirty_bit-when-changing-anonymous-names.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via various branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there most days ------------------------------------------------------ From: "David Hildenbrand (Arm)" Subject: mm/madvise: preserve VMA_SOFTDIRTY_BIT when changing anonymous names Date: Fri, 23 Oct 2026 14:47:29 +0100 When changing the anonymous VMA name, madvise_update_vma() calls vma_modify_name() to possibly merge with adjacent VMAs. We don't call vma_modify_flags() and consequently don't obtain the new VMA flags. Later in the function we update the VMA flags to the stale new_vma_flags we obtained before. This can result in us losing the VMA_SOFTDIRTY_BIT flag set on a VMA we just merged with. There is no need to update the VMA flags at all, so just exit early. This skips calling khugepaged_enter_vma(), but since the flags didn't change this is fine. [ljs@kernel.org: minor edit of commit message, rebased] Link: https://lore.kernel.org/20261023-fix-vma-atomic-v1-3-8ff4fae1fc85@kernel.org Fixes: 9a10064f5625 ("mm: add a field to store names for private anonymous memory") Signed-off-by: David Hildenbrand (Arm) Signed-off-by: Lorenzo Stoakes (ARM) Signed-off-by: Andrew Morton Reviewed-by: Lorenzo Stoakes (ARM) Cc: Liam R. Howlett Cc: Vlastimil Babka Cc: Mike Rapoport Cc: Suren Baghdasaryan Cc: Michal Hocko Cc: Jann Horn Cc: Pedro Falcato Cc: Davidlohr Bueso Cc: SJ Park Cc: Kees Cook Cc: Colin Cross Cc: --- mm/madvise.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/mm/madvise.c~mm-madvise-preserve-vma_softdirty_bit-when-changing-anonymous-names +++ a/mm/madvise.c @@ -177,6 +177,9 @@ static int madvise_update_vma(vm_flags_t /* vm_flags is protected by the mmap_lock held in write mode. */ vma_start_write(vma); + if (set_new_anon_name) + return replace_anon_vma_name(vma, anon_name); + vma_overwrite_flags(vma, new_vma_flags); /* * If the vma become good for khugepaged to scan, @@ -186,9 +189,6 @@ static int madvise_update_vma(vm_flags_t if (vma_flags_test(&new_vma_flags, VMA_HUGEPAGE_BIT)) khugepaged_enter_vma(vma, vma_flags_to_legacy(new_vma_flags)); - if (set_new_anon_name) - return replace_anon_vma_name(vma, anon_name); - return 0; } _ Patches currently in -mm which might be from david@kernel.org are mm-fix-address-wraparound-when-scanning-large-folio-ptes.patch mm-hugetlb-fix-use-after-free-in-hugetlb_mfill_atomic_pte.patch mm-hugetlb-tolerate-uffd-bits-set-without-uffd-for-prot_none-ptes.patch mm-hugetlb-tolerate-uffd_wp-markers-outside-uffd-wp-vmas.patch mm-mremap-fix-calling-fixup_hugetlb_reservations-on-the-wrong-vma.patch arm64-mm-move-__check_safe_pte_update-fix.patch mm-sparse-move-mem_section-init-to-sparse_extreme_init.patch mm-sparse-refactor-sparse_sections_init.patch mm-sparse-move-initialization-of-section-metadata-to-sparse_metadata_init.patch mm-sparse-rename-and-cleanup-sparse_init_nid.patch mm-sparse-cleanup-sparse_init_one_section.patch mm-sparse-rename-__highest_present_section_nr-to-__highest_used_section_nr.patch mm-sparse-remove-pfn_in_present_section.patch mm-sparse-move-__highest_used_section_nr-handling.patch scripts-gdb-mmpy-remove-fallbacks-for-section_has_mem_map-and-section_is_early.patch mm-sparse-remove-section_marked_present.patch mm-sparse-remove-flags-parameter-from-sparse_init_one_section.patch fs-proc-page-clarify-comment-in-get_max_dump_pfn.patch mm-memory_hotplug-drop-config_have_arch_pfn_valid-handling-from-pfn_to_online_page.patch vmcoreinfo-export-section_has_mem_map.patch mm-disallow-ioremaping-ordinary-ram-in-generic_access_phys.patch mm-userfaultfd-only-allocate-anon_vma-in-cow-mappings.patch mm-hugetlb-disable-pmd-sharing-for-uffd-missing-mode.patch mm-vma-write-lock-source-vma-before-duplicating-it-in-__split_vma.patch mm-madvise-preserve-vma_softdirty_bit-when-changing-anonymous-names.patch