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 421F2C98318 for ; Sat, 26 Sep 2026 10:41:50 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 4D7306B0099; Sat, 26 Sep 2026 06:41:49 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 4ABA76B009B; Sat, 26 Sep 2026 06:41:49 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 376D26B009D; Sat, 26 Sep 2026 06:41:49 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 158CB6B0099 for ; Sat, 26 Sep 2026 06:41:49 -0400 (EDT) Received: from smtpin04.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 99BD54082D for ; Sat, 26 Sep 2026 10:41:48 +0000 (UTC) X-FDA: 85255572696.04.DA8EBC8 Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf03.hostedemail.com (Postfix) with ESMTP id D5E8720004 for ; Sat, 26 Sep 2026 10:41:46 +0000 (UTC) Authentication-Results: imf03.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=FOsVDr1l; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf03.hostedemail.com: domain of ljs@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=ljs@kernel.org ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1790419306; b=IRgkGfaCHc6XfAUfm2MRDpuAGoIJdGQXxLT/4ZnrjYz1rfM8Ig7RV0GQzmfaCAHszXTxvG Lk/qjWU/N8ic9vb83dYGYTmINWncMQTodg6uIzM+D+RkpteubIGp39MC+R55+hg8SlEiId qfftUhZ5QA0XW1Ak10UgG1RF8/vw3vo= ARC-Authentication-Results: i=1; imf03.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=FOsVDr1l; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf03.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=1790419306; 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=7S7XXctTJTYqey2LHZ5itf+wJ0rIL+/9j15PCk6wOgnx+wBW6UMfdn8XtJgfeax3pctAwA XwE5XnCpPNoNRN0FBIeLqjI9VAwbKzG0G3/NLs/SOIdJcKc6rND4hMsQ7dytmKTdhOeMyX v0MuvVkVMkACGuLw51fBwcFV1z4W/4s= Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 3126C405DA; Sat, 26 Sep 2026 10:41:46 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id ABFB01F000FF; Sat, 26 Sep 2026 10:41:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790419306; bh=7INaOtP/gm2Q0CwFqGyhMMm+FXe4/enBYyOAMoEMKqg=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=FOsVDr1lPbdLbth/FdBj5KzXf0oIdA6hCu9mLssK1wFzaBK7SOzL2rFrbZQ8bHdFb +NRHHqxQudc2nRYJ1z6B2okgHcmH3Qa8RHn2nNuv+gzZORsamL5057k+nLTZvMks2H CQvk+OGjt0XOPqUwSaY/SaIaxC2RNRJyuugqLkgdUKOT1BZgeVZNC79AGrl60NU85U xozIGYhzxWRg56hAQEfbIaBWA8PZWVor0VpmS3L4B8+Dgbs2ThIn5DOPdbqsDUpJjy zWbmPHl6dHArcrZuIrxNf4gxZ1w0140QygSC+R/wcRCO2cVNCT7sZ/FMNZYhQh2lCs 5YMpWKbsnVYSQ== From: "Lorenzo Stoakes (ARM)" Date: Sat, 26 Sep 2026 11:41:10 +0100 Subject: [PATCH v3 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: <20260926-map-private-dev-zero-v3-5-d4781e84ccfc@kernel.org> References: <20260926-map-private-dev-zero-v3-0-d4781e84ccfc@kernel.org> In-Reply-To: <20260926-map-private-dev-zero-v3-0-d4781e84ccfc@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=owGbwMvMwCV2fu7ZrsZH9SKMp9WSGLK2L/ThnMwp/NdRf3l60KLN0u0+J8QnJbIkff2y9ehr/ qNu7dLdHaUsDGJcDLJiiizPv4jvDxIJm9d5wd8NZg4rE8gQBi5OAZjIzXiG/9nudyI6qi5MLnc9 UZecrdL263/01u7jldNfqDkUzHU8uIWR4WzMwkTmt7nexn/yZ6asiFzVbydhudHvRFBUX8SlTav FOQE= X-Developer-Key: i=ljs@kernel.org; a=openpgp; fpr=E7F417BF5214569E89D04F46CF9DCD8A81E27F14 X-Rspamd-Server: rspam06 X-Stat-Signature: ybotapih9bi7z1gr88s95n1j9hjab5hn X-Rspam-User: X-Rspamd-Queue-Id: D5E8720004 X-HE-Tag: 1790419306-984557 X-HE-Meta: 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 L1kFNBqG 10x1Xc4ITlZwIMDmPeJdK5vZCWqaD2q4WP0NDYzfK2XVtD0XSIsd8hQVPrH+/nZjourZJIGL2x7sVk0HrdkX6ooVLQq19+dWIRwVWmWO3C+5Pj7dk5ldBOb0gCNaskagovPsRwH/TywmoNnX1eHcxmzMPlTyuSs1YhV+zLdtyQcFTXwNbUal92KNpwYee2c7S5tnBmUjfg/GUtx8YVu3rA33/gvQ2ExrDlKoSTbUX6I1yOIAYO6chabWN1t9Cgh2jskxOs72MTrj0/Mq10YQdUUQOYVb1wzFB6mSX 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