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 251E936EA93 for ; Wed, 2 Sep 2026 19:22:03 +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=1788376924; cv=none; b=Yl4p0d83MvRMOKDcifrFFUTvuUEnBs0Zn0569A2eVg4wG+KknQ2t02OR7BMPpQMSDv34WG/xz4MpyxuqS+UJ3b2kkEQofafPnJdiiiLbhRuTcW/DY6VlR/iZyj1Zr6JoYWOssBF8W/c85HFEnLUdMS0PbVKVbsZSSzwtIvpYZxw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788376924; c=relaxed/simple; bh=M2q55CdYllZtJG47u/wLbkEmEsoBZ4BaKWuJ6WcZY/I=; h=Date:To:From:Subject:Message-Id; b=IA5QGbbGyeb9gRL/Ue7KIoFZbWFf6gr57bwbmpBCMiHHj1lZmz/x36ajAFwFiFVe81Ybc50+ltLXFbzYWs8atY/CxWnIwz4slHUDxTY8zh6FFAPlKwoA840zgRRSlRtC4cb8dct74hsxMpDuo1QCWQv4Z9vLViBhPkSFUzdJffA= 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=bhyWudt0; 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="bhyWudt0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EE2331F000E9; Wed, 2 Sep 2026 19:22:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1788376923; bh=dGRjj3UHJHcspCIur9sTfNbOoG3APZGjZGgdZ0PPWX8=; h=Date:To:From:Subject; b=bhyWudt0kG496GykKcaUhNzSvP2R0NUcTm6B/hCE/UXwyLgBblmrtMo0blkmj/zFM 1SRgJczj8NxCLFkhhOP4pYrGceL7AJ9B7iEIP/UTKS4UBoxbWfwh9q50UFpjB4cGrG a37gFtmysGMIevDqZv0+Opz56J5zBgVBTwDfKTGs= Date: Wed, 02 Sep 2026 12:22:02 -0700 To: mm-commits@vger.kernel.org,willy@infradead.org,vbabka@kernel.org,surenb@google.com,rppt@kernel.org,pfalcato@suse.de,mhocko@suse.com,liam@infradead.org,jannh@google.com,jack@suse.cz,hughd@google.com,gregkh@linuxfoundation.org,david@kernel.org,baolin.wang@linux.alibaba.com,arnd@arndb.de,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-new branch Message-Id: <20260902192202.EE2331F000E9@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-new 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-new branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Note, mm-new is a provisional staging ground for work-in-progress patches, and acceptance into mm-new is a notification for others take notice and to finish up reviews. Please do not hesitate to respond to review feedback and post updated versions to replace or incrementally fixup patches in mm-new. The mm-new branch of mm.git is not included in linux-next If a few days of testing in mm-new is successful, the patch will me moved into mm.git's mm-unstable branch, which is included in linux-next 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: Wed, 02 Sep 2026 19:00:22 +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/20260902-map-private-dev-zero-v1-5-a578c730cec7@kernel.org Signed-off-by: Lorenzo Stoakes (ARM) 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 Cc: Pedro Falcato Cc: Suren Baghdasaryan Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- tools/testing/vma/tests/mmap.c | 37 +++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) --- 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 +45,44 @@ static bool test_mmap_region_basic(void) return true; } +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); + struct file file = { + .f_op = &zero_fops, + }; + 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 mm-mremap-reset-unfaulted-vma-page-offset-for-mremap_dontunmap.patch mm-secretmem-properly-account-locked-pages.patch mm-huge_memory-bypass-thp-tuneables-for-huge-pfnmap-mappings.patch mm-mremap-account-mm-locked_vm-correctly-for-mremap_dontunmap.patch mm-vma-correctly-unaccount-on-mmap_prepare-failure.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