From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 8CD68C79FA1 for ; Tue, 8 Sep 2026 11:25:10 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 83D116B009B; Tue, 8 Sep 2026 07:25:07 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 79F7A6B009D; Tue, 8 Sep 2026 07:25:07 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 68E346B009E; Tue, 8 Sep 2026 07:25:07 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 471366B009B for ; Tue, 8 Sep 2026 07:25:07 -0400 (EDT) Received: from smtpin27.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 93D5C160500 for ; Tue, 8 Sep 2026 11:25:06 +0000 (UTC) X-FDA: 85190363412.27.DD40224 Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf16.hostedemail.com (Postfix) with ESMTP id C7BCC180005 for ; Tue, 8 Sep 2026 11:25:04 +0000 (UTC) Authentication-Results: imf16.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=MCMynEAK; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf16.hostedemail.com: domain of ljs@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=ljs@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1788866704; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=7INaOtP/gm2Q0CwFqGyhMMm+FXe4/enBYyOAMoEMKqg=; b=kNKyhNS37tyzfnS5+22OCw3eryfg9sVAwRI2sWdnk/NLAoD4rlvyItKN81aJYSaIwlQ6bP kxJOF5YukKm8uKRBkqhU8OPjk//ysnciQro0G/rCy0o+Rq6yxvupSM2UljLW3wb/k3l2TR BeM10PwZL4NFcJMRzU+SJnzR11PcH6A= ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1788866704; b=j8syJsGQUvHnmTOcZ49La6yA5EQLlWLFP08QzfSK3EAqdU9i356IPyXuKYJMbfRqXFGxKq ocGLlKNWV0SIJeTgeJfc7OQ4ditv4W6QPitoNqJHh8Ge1QZfCZBvwuZDN+Joch1E9tQJoG MnNHcRnWEmE/3RTz86Gts4LPqxaIBLQ= ARC-Authentication-Results: i=1; imf16.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=MCMynEAK; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf16.hostedemail.com: domain of ljs@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=ljs@kernel.org Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 1AEF743F72; Tue, 8 Sep 2026 11:25:04 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 84AD51F00ACA; Tue, 8 Sep 2026 11:24:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788866704; bh=7INaOtP/gm2Q0CwFqGyhMMm+FXe4/enBYyOAMoEMKqg=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=MCMynEAKWBBtZhM3TavPM2jvsMzLi/wfyDztSX3NadK30N7sH/KYNxbJTPna0++4M lE5/YW5SRBTlhkna4Lws5EybILgPvC0mz3bRN3o/XuXaHJSrijVmszq4RtwnMsPVBk tOxdnuRIffeKcofQSiJ2BFhlxP7re6LrwYSQqSruLSMCYgIi7gSFC1fU3mWxbSwn4C 2U+Gg1vY0dCzE7kFhijpKTkoX/Y/4vufVgfmUDopjMu7NmDgrK2ifxh9J+NzmNpcQz W22w2Kx727HvIXnbGmnxss/iKzUM2ixk4xg/yUsDdYwCClDW/MQzaRRQij+TWvnTyd xTbP10Rd5uwfA== From: "Lorenzo Stoakes (ARM)" Date: Tue, 08 Sep 2026 12:23:42 +0100 Subject: [PATCH v2 5/6] tools/testing/vma: add test to assert MAP_PRIVATE-/dev/zero is anon MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260908-map-private-dev-zero-v2-5-acc7b5625305@kernel.org> References: <20260908-map-private-dev-zero-v2-0-acc7b5625305@kernel.org> In-Reply-To: <20260908-map-private-dev-zero-v2-0-acc7b5625305@kernel.org> To: Arnd Bergmann , Greg Kroah-Hartman , Andrew Morton , "Liam R. Howlett" , Vlastimil Babka , Jann Horn , Pedro Falcato , David Hildenbrand , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Hugh Dickins , Baolin Wang , "Matthew Wilcox (Oracle)" , Jan Kara Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kselftest@vger.kernel.org, "Lorenzo Stoakes (ARM)" X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=openpgp-sha256; l=1881; i=ljs@kernel.org; h=from:subject:message-id; bh=MuW0MgECKFqsgKYanDvHZ2zzAEiQ7iCtWQ9chN/jOZY=; b=owGbwMvMwCV2fu7ZrsZH9SKMp9WSGLLmfyg80KuTMs9Z7srfjee93Bu2eq+dea5h49YnP6/36 a5/o1EQ3FHKwiDGxSArpsjy/Iv4/iCRsHmdF/zdYOawMoEMYeDiFICJyGQzMhzsOGP3+heLprbt OzWrS8qzdvEn8PpYXC9/MOmUscrVH5sY/udIy2aduTOvet7fSVJMds/c3ydt2yGZ4hOf4VAdVFu zjAEA X-Developer-Key: i=ljs@kernel.org; a=openpgp; fpr=E7F417BF5214569E89D04F46CF9DCD8A81E27F14 X-Rspam-User: X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: C7BCC180005 X-Stat-Signature: q14swndfbpk48zh7y86nixtegxr8hbjx X-HE-Tag: 1788866704-29858 X-HE-Meta: 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 vxofKVzg A2FOhFk6j7wQResILgTdoCU2ZWKnEhKTlv4ZBQugIh23b1srIWTk8kokgMUKzOs5Xj+2h072/D4fHl1ICG4kzwTV2rO3GwwfDnBG93J34b1nfEmqw6WFsALLtNOBdM9A50AdwrMjViEI0CacttAVwKRupQoLEJXbPmsUViuTFfrc5fblvq4KDuZX6qvdu7+vdYygevKbWW1thR6CYGRhcOdKYEtmdc1BoyP3INz0URYAhi+BCpPCAp380p25FJeBilClC+FwS/8uVMt5fbBv6x/yi7jTksPHf8G2W Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: 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. Acked-by: David Hildenbrand (Arm) Signed-off-by: Lorenzo Stoakes (ARM) --- tools/testing/vma/tests/mmap.c | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) diff --git a/tools/testing/vma/tests/mmap.c b/tools/testing/vma/tests/mmap.c index c85bc000d1cb..fa73faff2262 100644 --- a/tools/testing/vma/tests/mmap.c +++ b/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); } -- 2.55.0