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 ED6DE47F779 for ; Thu, 6 Aug 2026 23:29:16 +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=1786058958; cv=none; b=MJGrd2HSYvkti7I5fTUeTyT3mNiBk+jIgVlcYXKORXFDTDx/rmtxXO8lmZFngjbsQmwuIdkY6E5t0zVCmC+P4NW3D1gaQ/d/8up6BQFXlVKop0oQEO+Ex3j/iXU7apWrdvSKaaAmeVD9QWNtJFJ/vmKT+339VbQnWPZnSdZ2/Qc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786058958; c=relaxed/simple; bh=aitpMqyN5es0NOVPppgzvgU7qnLznI1+VCT6iHswtKs=; h=Date:To:From:Subject:Message-Id; b=AePaAmyCnInwWrgsYPNrs+z7d4i/fPiWpF/oDf9TTRbEyqhE2ix39I01jwsjz7mkOYqG/XJFzbZWhcJVKRw0Wbghk8b1eFLayEqHYd8q3dFwPcB0BHsuTQAjsbu220lfHirkkd7t7YdKkluFzLUg3hKL6xF465PaG1wMeo7VKhs= 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=udvG8RaA; 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="udvG8RaA" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C1DCE1F000E9; Thu, 6 Aug 2026 23:29:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1786058956; bh=ob096L34z7hGvjkwQRiTbenwiHB6Vvsn9l05lJdoyPs=; h=Date:To:From:Subject; b=udvG8RaAnHCAGkB+6DORRQJN3KczDoXxed5Uu1bg9zCbAquy8FuLqgNB+U2XGsDWz f23eVYi9Y0oWi8I4Ed0PS8+77fy2pJGVtjG0s+3f3qvduG6/LGiYK3rHFs5zdKBxyh +jYwovb8RmsFcMcFb1d+9QzfAyp0KjCu/iOsmgvo= Date: Thu, 06 Aug 2026 16:29:16 -0700 To: mm-commits@vger.kernel.org,ljs@kernel.org,akpm@linux-foundation.org From: Andrew Morton Subject: + tools-testing-vma-add-test-to-assert-map_private-dev-zero-is-anon.patch added to mm-unstable branch Message-Id: <20260806232916.C1DCE1F000E9@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: tools/testing/vma: add test to assert MAP_PRIVATE-/dev/zero is anon has been added to the -mm mm-unstable branch. Its filename is tools-testing-vma-add-test-to-assert-map_private-dev-zero-is-anon.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/tools-testing-vma-add-test-to-assert-map_private-dev-zero-is-anon.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: "Lorenzo Stoakes (ARM)" Subject: tools/testing/vma: add test to assert MAP_PRIVATE-/dev/zero is anon Date: Thu, 06 Aug 2026 21:21:44 +0100 Now we've made MAP_PRIVATE-mapped /dev/zero mappings truly anonymous, add a VMA userland test to assert that this is the case and everything is as we would expect for an anonymous mapping. Link: https://lore.kernel.org/20260806-b4-scalable-cow-virt-pgoff-v4-19-ab318a350404@kernel.org Signed-off-by: Lorenzo Stoakes (ARM) Cc: Adrian Hunter Cc: Alexander Deucher Cc: Alexander Gordeev Cc: Alexander Shishkin Cc: Alistair Popple Cc: Arnaldo Carvalho de Melo Cc: Arnd Bergmann Cc: Baolin Wang Cc: Baoquan He Cc: Barry Song Cc: Boris Brezillon Cc: Byungchul Park Cc: Chengming Zhou Cc: Chris Li Cc: Christan König Cc: Christian Borntraeger Cc: Claudio Imbrenda Cc: Dave Airlie Cc: David Hildenbrand (Arm) Cc: Dev Jain Cc: Gerald Schaefer Cc: Greg Kroah-Hartman Cc: Gregory Price (Meta) Cc: Harry Yoo Cc: Heiko Carstens Cc: Huang Ray Cc: "Huang, Ying" Cc: Ian Rogers Cc: Ingo Molnar Cc: James Clark Cc: Jan Kara Cc: Jann Horn Cc: Janosch Frank Cc: Jason Gunthorpe Cc: Jiri Olsa Cc: John Hubbard Cc: Joshua Hahn Cc: Kairui Song Cc: Kees Cook Cc: Kemeng Shi Cc: Lance Yang Cc: Liam R. Howlett Cc: Liviu Dudau Cc: Maarten Lankhorst Cc: Marc Rutland Cc: "Masami Hiramatsu (Google)" Cc: Matthew Auld Cc: Matthew Brost Cc: Matthew Wilcox (Oracle) Cc: Maxime Ripard Cc: Miaohe Lin Cc: Michal Hocko Cc: Mike Rapoport Cc: Muchun Song Cc: Namhyung kim Cc: Naoya Horiguchi Cc: Nhat Pham Cc: Nico Pache Cc: Oleg Nesterov Cc: Oscar Salvador Cc: Pedro Falcato Cc: Peter Xu Cc: Peter Zijlstra Cc: Rakie Kim Cc: Rik van Riel Cc: Rodrigo Vivi Cc: Ryan Roberts Cc: Steven Price Cc: Suren Baghdasaryan Cc: Sven Schnelle Cc: Cc: Thomas Hellström Cc: Thomas Zimemrmann Cc: Vasily Gorbik Cc: Vlastimil Babka Cc: Xu Xin Cc: Zi Yan Signed-off-by: Andrew Morton --- tools/testing/vma/include/dup.h | 1 tools/testing/vma/tests/mmap.c | 50 ++++++++++++++++++++++++++++++ 2 files changed, 51 insertions(+) --- a/tools/testing/vma/include/dup.h~tools-testing-vma-add-test-to-assert-map_private-dev-zero-is-anon +++ a/tools/testing/vma/include/dup.h @@ -20,6 +20,7 @@ struct task_struct *get_current(void); #define MAJOR(dev) ((unsigned int) ((dev) >> MINORBITS)) #define MINOR(dev) ((unsigned int) ((dev) & MINORMASK)) +#define MKDEV(ma, mi) (((ma) << MINORBITS) | (mi)) #define S_IFMT 00170000 #define S_IFCHR 0020000 --- a/tools/testing/vma/tests/mmap.c~tools-testing-vma-add-test-to-assert-map_private-dev-zero-is-anon +++ a/tools/testing/vma/tests/mmap.c @@ -45,7 +45,57 @@ static bool test_mmap_region_basic(void) return true; } +static int dummy_mmap_prepare(struct vm_area_desc *desc) +{ + return 0; +} + +static bool test_pure_anon_dev_zero(void) +{ + const vma_flags_t vma_flags = mk_vma_flags(VMA_READ_BIT, VMA_WRITE_BIT, + VMA_MAYREAD_BIT, VMA_MAYWRITE_BIT); + const struct file_operations f_op = { + .mmap_prepare = dummy_mmap_prepare, + }; + struct inode inode = { + .i_mode = S_IFCHR, + .i_rdev = MKDEV(MEM_MAJOR, DEVZERO_MINOR), + }; + struct file file = { + .f_inode = &inode, + .f_op = &f_op, + }; + struct mm_struct mm = {}; + struct vm_area_struct *vma; + unsigned long addr; + VMA_ITERATOR(vmi, &mm, 0); + + current->mm = &mm; + + /* + * Map a MAP_PRIVATE-/dev/zero mapping at address 0x300000 with a page + * offset of 0x10, which we expect to be reset to the anonymous page + * offset. + */ + addr = __mmap_region(&file, 0x300000, 0x3000, vma_flags, 0x10, NULL); + ASSERT_EQ(addr, 0x300000); + + /* Assert that it truly is an anonymous mapping. */ + vma = vma_lookup(&mm, addr); + ASSERT_NE(vma, NULL); + ASSERT_TRUE(vma_is_anonymous(vma)); + ASSERT_EQ(vma->vm_file, NULL); + ASSERT_EQ(vma->vm_private_data, NULL); + /* Expect anonymous page offsets. */ + ASSERT_EQ(vma->vm_pgoff, 0x300); + ASSERT_EQ(vma_start_anon_pgoff(vma), 0x300); + + cleanup_mm(&mm, &vmi); + return true; +} + static void run_mmap_tests(int *num_tests, int *num_fail) { TEST(mmap_region_basic); + TEST(pure_anon_dev_zero); } _ Patches currently in -mm which might be from ljs@kernel.org are x86-mm-pat-acquire-init_mm-write-lock-on-collapse-to-avoid-uaf.patch x86-mm-pat-acquire-init_mm-read-lock-on-attribute-change-to-avoid-uaf.patch x86-mm-pat-allocate-split-page-tables-as-kernel-page-tables.patch mm-introduce-vma_flags_can_grow-and-vma_can_grow.patch mm-vma-update-do_mmap-to-use-vma_flags_t.patch mm-convert-__get_unmapped_area-to-use-vma_flags_t.patch mm-update-generic_get_unmapped_area-to-use-vma_flags_t.patch mm-prefer-mm-def_vma_flags-in-mm-logic.patch mm-vma-convert-vm_pgprot_modify-to-use-vma_flags_t-and-rename.patch mm-vma-rename-vma_get_page_prot-to-vma_flags_to_page_prot.patch mm-introduce-vma_get_page_prot-and-use-it.patch mm-vma-update-create_init_stack_vma-to-use-vma_flags_t.patch mm-vma-convert-miscellaneous-uses-of-vma-flags-in-core-mm.patch mm-mlock-convert-mlock-code-to-use-vma_flags_t.patch mm-mprotect-convert-mprotect-code-to-use-vma_flags_t.patch mm-mremap-convert-mremap-code-to-use-vma_flags_t.patch mm-mseal-remove-superfluous-comments-fix-confusion-around-mm.patch mm-mseal-limit-scope-of-mseal-address-zero-to-address-zero.patch mm-mseal-remove-further-superfluous-comments-do_mseal.patch mm-vma-introduce-vma-anon-page-offset-field-and-add-helpers.patch mm-provide-vma_is_cow_mapping-and-remove-is_cow_mapping.patch mm-introduce-linear_anon_page_index.patch mm-abstract-vma_address-and-introduce-vma_anon_address.patch mm-update-print_bad_page_map-to-show-anon-index-if-appropriate.patch mm-introduce-and-use-vma_filebacked_address.patch mm-vma-fix-self-merge-check-in-copy_vma.patch tools-testing-vma-add-tests-for-copy_vma-self-merge.patch mm-propagate-vma-anonymous-page-offset-on-map-remap-split-merge.patch mm-rmap-track-whether-the-page-vma-mapped-pgoff-is-anonymous.patch mm-clean-up-vma_address_end.patch mm-huge_memory-update-remove_migration_pmd-to-accept-a-folio.patch mm-migrate-calculate-large-folio-page-index-using-pfn.patch mm-rmap-use-anon-pgoff-to-track-map_private-file-backed-anon-folios.patch tools-testing-vma-expand-vma-merge-tests-to-assert-anon-pgoff.patch tools-testing-selftests-mm-test-anonymous-page-offset-merge-behaviour.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-add-some-missing-includes-to-mm-local-headers.patch