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 26676C5CFCF for ; Wed, 12 Aug 2026 17:18:05 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id D6E1D6B02D2; Wed, 12 Aug 2026 13:18:03 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D45B16B02D3; Wed, 12 Aug 2026 13:18:03 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C5B476B02D4; Wed, 12 Aug 2026 13:18:03 -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 9B90D6B02D2 for ; Wed, 12 Aug 2026 13:18:03 -0400 (EDT) Received: from smtpin13.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 209991603FE for ; Wed, 12 Aug 2026 17:18:03 +0000 (UTC) X-FDA: 85093275246.13.D4F74FF Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf22.hostedemail.com (Postfix) with ESMTP id 504A2C000D for ; Wed, 12 Aug 2026 17:18:01 +0000 (UTC) Authentication-Results: imf22.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=PqOPKr1U; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf22.hostedemail.com: domain of david@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=david@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1786555081; 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=ORVjW2+uzGEZ3P9C+o+jbVG9nyuLf1KgGswOIiDbPpU=; b=LxCy05bMQYz4wfDCY4LBKLefH5et+R/HRoN1jvHdAqjFace8I9m/Qt+XrNf+fO62LfJ9/p YwFZvNJ0iKz8leM63YM5soCwbv8HonD8KpZuF5BKrnqFD1ngZgEvAysFiFHp97nkn9fg8E wgb2rrISvaJL36jfdLp9MmsoOwSCd5E= ARC-Authentication-Results: i=1; imf22.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=PqOPKr1U; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf22.hostedemail.com: domain of david@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=david@kernel.org ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1786555081; b=x3lmTwj7UQ896hEexJfx7JQWkrH3uBBe+mD1exvlvYyK1kGUcW/a+2coNkhcSNFT8ZZRrP QWYN/8vYPmitUl0AaSaYWrWAam5CDKz7e08RDlLDKaxSRJ84b6oel76f0ZiqLgoJJ1Yl3d ZPGS015rHcTEXAR5vGqJC7ijqnCNHp0= Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 5FC9540317; Wed, 12 Aug 2026 17:18:00 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B6AFE1F000E9; Wed, 12 Aug 2026 17:17:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1786555080; bh=ORVjW2+uzGEZ3P9C+o+jbVG9nyuLf1KgGswOIiDbPpU=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=PqOPKr1U5/Zq/Agb3zTnII31kLHupSik1RfSnUbFYYJxc/LOWQA5OndnLSlUrwPNe TYSzKj9S+0Qdc2Q1gyaM4kyDT9CQBarGPj+5FLHb/JsSWspuQ8Pfc5iIUUiZ7+MXA1 16JtkYXjjCOcDhxarJebImOL+ify/0dGzPawerSv91sViOfv2uYxFsF3632WBw9LMW is9aol95hYPNTHbXpseyT308oBoiSv1xSoEYR4GY5olBVeew0/AFjSHvgeC616xXK3 zyED/ApTUhikIHDO1E9ansj2GKB5DZX6f0KX38OwbwEGfQusq4zozJXxxC6phj9ODs l1WxGP9jFFnlw== Message-ID: <5d1a35d2-8541-44d5-8958-1efa9773d7bb@kernel.org> Date: Wed, 12 Aug 2026 19:17:39 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 19/20] tools/testing/vma: add test to assert MAP_PRIVATE-/dev/zero is anon To: "Lorenzo Stoakes (ARM)" , Andrew Morton , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Jann Horn , Pedro Falcato , "Matthew Wilcox (Oracle)" , Jan Kara , Miaohe Lin , Naoya Horiguchi , Rik van Riel , Harry Yoo , Lance Yang , Kees Cook , Zi Yan , Baolin Wang , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Usama Arif , Matthew Brost , Joshua Hahn , Rakie Kim , Byungchul Park , Gregory Price , Ying Huang , Alistair Popple , Peter Xu , Xu Xin , Chengming Zhou , Arnd Bergmann , Greg Kroah-Hartman , Christian Borntraeger , Janosch Frank , Claudio Imbrenda , Alexander Gordeev , Gerald Schaefer , Heiko Carstens , Vasily Gorbik , Sven Schnelle , Alex Deucher , =?UTF-8?Q?Christian_K=C3=B6nig?= , David Airlie , Simona Vetter , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , Boris Brezillon , Steven Price , Liviu Dudau , Huang Rui , Matthew Auld , =?UTF-8?Q?Thomas_Hellstr=C3=B6m?= , Rodrigo Vivi , Masami Hiramatsu , Oleg Nesterov , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , James Clark , Jason Gunthorpe , John Hubbard , Muchun Song , Oscar Salvador , Chris Li , Kairui Song , Kemeng Shi , Nhat Pham , Baoquan He , Youngjun Park Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kselftest@vger.kernel.org, kvm@vger.kernel.org, linux-s390@vger.kernel.org, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, intel-xe@lists.freedesktop.org, linux-perf-users@vger.kernel.org, linux-trace-kernel@vger.kernel.org References: <20260806-b4-scalable-cow-virt-pgoff-v4-0-ab318a350404@kernel.org> <20260806-b4-scalable-cow-virt-pgoff-v4-19-ab318a350404@kernel.org> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit X-Stat-Signature: pn4534xhekm6q9o5fkbo5fshqf41ijm8 X-Rspamd-Queue-Id: 504A2C000D X-Rspamd-Server: rspam03 X-Rspam-User: X-HE-Tag: 1786555081-42763 X-HE-Meta: U2FsdGVkX1+sbeEFU/uycn1p2zGfIst0e8FIzs8725ioG8dqa1Q09vuI8qShFoWUKp4sVVye7GScKWUetVSQCHriJdvqXPonTg8zBU+V0euKvH/J/JH9ajsxAoP2wikRpKCmYMDHVyRr7RWL/Da4qoWvAg4xL6FHNVLA1cysGLqBx4wYwRjrC5jiJGv1Z4Wo9RTWUywEkQ5ZLh5ulVP3/xDtDvgtoVY5kSEyR00PHaCtvczzDdthfWV3ma+SMOBEHbCYbWm3HpALOXrLaGpLvM4uhp6FlEJJlO6akCsWCYdvff3IQqE3+NZB/9zenJy4loPHDvGPIwiOcH/ABip6+XZJEZkwSCGiM/P8ajgI3FEqW+XkNClL8+OenXBbfo0gdwT8affzglfHvRzLvKKRw0Y1YMc2FV/5e18CNL+RLV/km7zxsVFlHp4xK2WNZeOaORUJmKcxW+W8Hm3+TXPaJbtamS7zoKF6KLJ3YC1/4J/zHjFkrtCtihUFaPp8d5r539iArXzWdPcLO4bKoRhds7S+1ofDAHQ3xSrDUv9SNCpg+IhEpDJGo14l91SXH4eSP27C4tWaME5egL6tDmZSJWeT+E0jA5h1Jqep3Hcp3pVUPuQeuYOGdDggIvmdvK0mOJDGTU2WBiMN3jdLpigpGuvWz2pDK6tAvo2bvPELQvVw7yO3evrOamSXemAAMaAXSAq1111PQe4CnXTfbTfXGt/0gfoyr+HWv9sT3ZtmN+YH5+GDZMP3Jrdes/k2Z0sBTP4KMDxgwqyEudV8L/763N0E4LnzNynp+t7+EHZHpPRphPol760G3lwfXmgVip8kjeiW4YwFJNLCXLkKZEA8oa9uCRLfPlrv6Pd36ATNitvIf4Mt1x6HVCKh4v4xnbVIBD8M8jJ31tixq/B24g+JeKD//LzVHfR+OzA9eZIYf8z0UeP8Wh7JxAb7HHrqTmJyeIRiGlAeFjtho5UYRVQ u7WZKgq7 N+vAfpG2uniFJE3BBmABH7m3ClSN0zhG+L9HbNupgCjAZEW4OkpbmqnMvgoDhqsN/oPLf88HjiJvNhEUaw7SvftH7GebgCU2DsU4kFdJKJPl5Ic3njbLE5PhklLTE7MMKBbnP2nx3R2IIOZXtD6mxiiuJAi0mQOzsSMQkbU0sJuyMOyV25SPtTzkDcrmzz+o9hbmW+jJJ9GDvDaXDP0BsXE9arFpe2cniMBSS1sc8K9UgGwK9YuKMRZMLcj5WezU2ZMRTo94oqtCYBHerhICuifa7AcocnjXLV+/g5agVZk1W4TztZClGIu/tSkMq3SPHr27x3Zq6gjNH0rSvXY31mx9ysi54kz+AgDMyj2Wy76DqskrbqoEccJrMSzK+zM0faGF+c07CxAnftuaTha3UmuRodA== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: > +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); > + When we go with a zero_vm_ops this gets a bit simpler (see schloppedi-schlop). > + 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); Yes, that looks good to me. Acked-by: David Hildenbrand (Arm) -- Cheers, David