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 7B8043C3F6B for ; Sun, 27 Sep 2026 21:48:05 +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=1790545687; cv=none; b=K0CfNfl6vBKe8Yi9wau/QKF9SR4KaeKmcvMjxJBaKnSdw3r168Onfdepkz3piaBfWZXKocfvcon2DK2tG4VNfBMpTtYmFXyeAI2in9KL9xi6oUFtiTUEWGcy7h0H2XJc/mcrG/ksNXzvnjyUJxXuIGNv59+U2Co2Mjae6W+34h8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790545687; c=relaxed/simple; bh=FvjvCJmFOnYATSNTf4xlsLDXPcK+DoM1FCc7aZE96MQ=; h=Date:To:From:Subject:Message-Id; b=LgT9W7HAP8fFv5GDNysH2nof0KGftYq+uRX4o+b6g5px/048yhaNtYBiLQnRTDwZbVYdegO+AbXAwMW8Zv+JuaLDSrcfE7nBGGDa0FhaDwRRUZswijswrH/D7OVRB7pYHlRPl24jQJMAwHyaw37XTXcTBjxNqLbjoomg+44TeTo= 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=YGPzlXS+; 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="YGPzlXS+" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E52821F00893; Sun, 27 Sep 2026 21:48:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1790545685; bh=s6R0vzbMfATBlA8I93aPLxbnzC54HNeViWeCX0JvcsU=; h=Date:To:From:Subject; b=YGPzlXS+LNhSbKdfDni4tDsx8UXpPcydBo5YF3UemfVNW1BiEMn7kkjSrIHPxadOe hkEMdOh3Hq293Q9WUo9Dysi8fd30+SpC9gj4BUQemlGVPyO8Sf3m0If9Rj9FL5WMnJ 2vneSLjHkqbf2TOoZ5/fdBqp+ovo8j8uVN3W1nFE= Date: Sun, 27 Sep 2026 14:48:04 -0700 To: mm-commits@vger.kernel.org,ljs@kernel.org,akpm@linux-foundation.org From: Andrew Morton Subject: [to-be-updated] mm-implement-file_is_dev_zero-to-uniquely-identify-dev-zero.patch removed from -mm tree Message-Id: <20260927214804.E52821F00893@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: implement file_is_dev_zero() to uniquely identify /dev/zero has been removed from the -mm tree. Its filename was mm-implement-file_is_dev_zero-to-uniquely-identify-dev-zero.patch This patch was dropped because an updated version will be issued ------------------------------------------------------ From: "Lorenzo Stoakes (ARM)" Subject: mm: implement file_is_dev_zero() to uniquely identify /dev/zero Date: Tue, 08 Sep 2026 12:23:39 +0100 To lay the foundation for a future change that converts MAP_PRIVATE-/dev/zero mappings to be truly anonymous, add the ability to uniquely identify these mappings. With the memory character device now part of mm/ this is trivially achievable through a file_is_dev_zero() predicate that simply tests that the file operation hooks are zero_fops. Also update userland VMA tests to expose file_is_dev_zero() and provide a stub zero_fops for testing. Link: https://lore.kernel.org/20260908-map-private-dev-zero-v2-2-acc7b5625305@kernel.org Signed-off-by: Lorenzo Stoakes (ARM) Signed-off-by: Andrew Morton Acked-by: David Hildenbrand (Arm) Cc: Arnd Bergmann Cc: Baolin Wang Cc: Greg Kroah-Hartman Cc: Hugh Dickins Cc: Jan Kara Cc: Jann Horn Cc: Liam R. Howlett Cc: Matthew Wilcox (Oracle) Cc: Michal Hocko Cc: Mike Rapoport (Microsoft) Cc: Pedro Falcato Cc: Suren Baghdasaryan Cc: Vlastimil Babka --- mm/char-mem.c | 13 +++++++++++++ mm/internal.h | 3 +++ tools/testing/vma/include/dup.h | 7 +++++++ tools/testing/vma/shared.c | 9 +++++++++ 4 files changed, 32 insertions(+) --- a/mm/char-mem.c~mm-implement-file_is_dev_zero-to-uniquely-identify-dev-zero +++ a/mm/char-mem.c @@ -31,6 +31,8 @@ #include #include +#include "internal.h" + #define DEVMEM_MINOR 1 #define DEVPORT_MINOR 4 @@ -707,6 +709,17 @@ static const struct memdev { #endif }; +/** + * file_is_dev_zero() - is the specified @file associated with the /dev/zero + * driver? + * @file: File to test. + * Returns: true if it is, false otherwise. + */ +bool file_is_dev_zero(const struct file *file) +{ + return file && file->f_op == &zero_fops; +} + static int memory_open(struct inode *inode, struct file *filp) { int minor; --- a/mm/internal.h~mm-implement-file_is_dev_zero-to-uniquely-identify-dev-zero +++ a/mm/internal.h @@ -1638,4 +1638,7 @@ static inline bool can_spin_trylock(void return true; } +/* char-mem.c */ +bool file_is_dev_zero(const struct file *file); + #endif /* __MM_INTERNAL_H */ --- a/tools/testing/vma/include/dup.h~mm-implement-file_is_dev_zero-to-uniquely-identify-dev-zero +++ a/tools/testing/vma/include/dup.h @@ -1641,3 +1641,10 @@ static inline pgoff_t linear_anon_page_i return pgoff; } + +extern const struct file_operations zero_fops; + +static inline bool file_is_dev_zero(const struct file *file) +{ + return file && file->f_op == &zero_fops; +} --- a/tools/testing/vma/shared.c~mm-implement-file_is_dev_zero-to-uniquely-identify-dev-zero +++ a/tools/testing/vma/shared.c @@ -12,6 +12,15 @@ const struct vm_operations_struct vma_du struct anon_vma dummy_anon_vma; struct task_struct __current; +static int mmap_zero_prepare(struct vm_area_desc *desc) +{ + return 0; +} + +const struct file_operations zero_fops = { + .mmap_prepare = mmap_zero_prepare, +}; + struct vm_area_struct *alloc_vma(struct mm_struct *mm, unsigned long start, unsigned long end, pgoff_t pgoff, vma_flags_t vma_flags) _ 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 mm-vmpressure-remove-window-size-todo.patch tools-testing-selftests-mm-add-missing-gitignore-entries.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-fix-mmap_prepare-file-handling-remove-file_doesnt_need_get.patch mm-vma-introduce-and-use-vma_can_merge.patch mm-consistently-validate-vma-state-after-mmap-hooks.patch mm-vma-ensure-mmap_prepare-doesnt-set-actions-on-a-mergeable-vma.patch mm-make-map_kernel_pages_-internal-and-unexported.patch mm-vma-tidy-up-map-kernel-pages-enum-values.patch mm-add-mmap-action-for-discontiguous-kernel-page-mapping.patch docs-filesystems-update-mmap_prepare-docs-for-discontig-kernel-pgs.patch drivers-usb-mon-update-to-use-mmap_prepare-map-kernel-pages.patch infiniband-update-hfi1-to-use-remap_vmalloc_range.patch selinux-reject-writable-opens-of-policy-file-drop-mmap-shared-write-check.patch alsa-pcm-use-vm_insert_page-to-map-pcm-status-page.patch bpf-arena-mark-arena_map_mmap-mappings-vm_mixedmap.patch mm-vma-add-vma_is_kernel_owned-predicates.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