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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 98AD3C88E6E for ; Mon, 14 Sep 2026 15:40:25 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id D85E310E1D6; Mon, 14 Sep 2026 15:40:24 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="HfT6yU8H"; dkim-atps=neutral Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by gabe.freedesktop.org (Postfix) with ESMTPS id 9482D10E1D6 for ; Mon, 14 Sep 2026 15:40:23 +0000 (UTC) Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 97EF06025A; Mon, 14 Sep 2026 15:40:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7AAAD1F000FF; Mon, 14 Sep 2026 15:40:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789400422; bh=mBF6+D5851OP0+RBXASeBH5sGFKcTHTWtmvG0ev37TI=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=HfT6yU8HaojhFMvk9XASK5imu2bqOTKnurQmiy6//QQT9JnJ7A2OWp3WVyisKXRPv IHWD6mzbSvvf+AZtpY1n/Ir2562C0cezM64uGVgOAPtNBERHDGaZAwIenkhxf9Lp8n Ia3qK0dObEeCJSlRyG6Wq9BCJ96GbY1TSwp7JqDL5pCFwFcw2r1xRHU9R7J3iLDydA 5G3b/iDTN6aXJTbk1/tGhU4ZOH4IF6Glt83ooxLVwQwuyOOlFUZLs2gliARgvgUw1Z 4lTGTf8aXMaClZgcw6dPg08zoHhS8l29ysC7+MTm0m/utmYsbdoL1MynkbAJYB5XLt +T/mXIrITmMhg== From: sashiko-bot@kernel.org Subject: Re: [PATCH v2 01/40] mm/vma: fix mmap_prepare file handling, remove file_doesnt_need_get To: =?utf-8?b?TG9yZW56byBTdG9ha2VzIChBUk0p?= Cc: "Christian Borntraeger" , linux-scsi@vger.kernel.org, "Heiko Carstens" , linux-rdma@vger.kernel.org, "Marc Zyngier" , linux-s390@vger.kernel.org, selinux@vger.kernel.org, bpf@vger.kernel.org, "Oliver Upton" , "Vasily Gorbik" , linux-perf-users@vger.kernel.org, kvm@vger.kernel.org, linux-trace-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, "Alexander Gordeev" , kvmarm@lists.linux.dev In-Reply-To: <20260914-b4-mmap-prepare-vma-flag-sanify-v2-1-7d9781ed5361@kernel.org> References: <20260914-b4-mmap-prepare-vma-flag-sanify-v2-0-7d9781ed5361@kernel.org> <20260914-b4-mmap-prepare-vma-flag-sanify-v2-1-7d9781ed5361@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Mon, 14 Sep 2026 15:40:21 +0000 Message-Id: <20260914154021.7AAAD1F000FF@smtp.kernel.org> X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: sashiko-reviews@lists.linux.dev Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" > The map->file_doesnt_need_get flag is confusing and the existing > implementation has holes. >=20 > Drivers are permitted to change the owning file of a mapping. If they do > so, they are required to take a reference on that file. >=20 > The mmap() operation which ultimately invokes __mmap_region() is guarante= ed > to drop the refcount for the original file the mapping was made under, but > this is not true for the replaced file. >=20 > This has been addressed so far by tracking map->file_doesnt_need_get, whi= ch > is rather poorly named and unfortunately fails to correctly track whether > or not an additional put were needed in a number of cases. >=20 > Make life easier by removing this flag, and instead drop the reference for > [ ... ] > No in-tree driver is impacted by the incorrect implementation of this > currently (no driver that does this is mergeable for one), so this does n= ot > need to be a fix. >=20 > Signed-off-by: Lorenzo Stoakes (ARM) Sashiko has reviewed this patch and found no issues. It looks great! --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260914-b4-mmap-pr= epare-vma-flag-sanify-v2-0-7d9781ed5361@kernel.org?part=3D1