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 X-Spam-Level: X-Spam-Status: No, score=-3.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B0B61C47095 for ; Wed, 7 Oct 2020 12:44:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 59DD320872 for ; Wed, 7 Oct 2020 12:44:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=ziepe.ca header.i=@ziepe.ca header.b="L3Snl2lK" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728272AbgJGMoN (ORCPT ); Wed, 7 Oct 2020 08:44:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43530 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727927AbgJGMoM (ORCPT ); Wed, 7 Oct 2020 08:44:12 -0400 Received: from mail-qk1-x741.google.com (mail-qk1-x741.google.com [IPv6:2607:f8b0:4864:20::741]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5F6C6C061755 for ; Wed, 7 Oct 2020 05:44:12 -0700 (PDT) Received: by mail-qk1-x741.google.com with SMTP id w12so2447877qki.6 for ; Wed, 07 Oct 2020 05:44:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ziepe.ca; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=YHwK7fj40rs6RtWBfMsDdiNwOc6I5e7hiW0vaeAiWPE=; b=L3Snl2lKZ0Efotdw5H66ICtk7hAPeqPHl2yvT2hFObgLWAEy3EBTXL+OsvS8u/QndV Pj12VmdFi1Z+tf74AMThconTJmYhkFSDG8iZx1jlaA7Czeyr7poiFxBLjV1keUOmp1a1 r6jTl4FOE/mmJjXmQ3zxvk1dmo6U3QKzXB0dREWbZ5bVe5DnC2HmgHKbEjSJ6zySfOog R+kS8ezo1stmGnlupvsVnR3bPxmU38krpYm29D741/i3IkmlnAWe/GfJ9rN+yP8YE0dg cFJCTIqTz/UvPJG/mR+/5L+YhDdX7fqDJnzC1ZYlkGVtaAUiADgRS6KwWpAwdsPJXKnQ JC2g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=YHwK7fj40rs6RtWBfMsDdiNwOc6I5e7hiW0vaeAiWPE=; b=GQWyEUYUVUgnqL8Bd0QIpUn45QXsxpeFnK1bU1+87BCy7FLpOZ4DNdRiSP9wcj6QJd CrFcfFPGnsLoJf4Ran9WJWOQaHu++0x6RGGc7q6YYGrLWOEwD9jSJO7pxyLYs9kJLIR6 Dn7JNKoboLUo2DRr5qdl7w/znSlYaGavyD37iD31fWQplROthLI4pDnd1uHJQRnCMbZn K0CZETrO5MpxdxxuZyNBOMrnbnqKwOGh7St4V1eiMYfaJnMMCl0AQQWuukTSjeO2+cFJ pXFV3T1MTpe6tJxGAA21D2wiK5jCAIE+WTunWTvybyvyYrSQ+Hb8eLrPu2Si3ReIH7wn WN3g== X-Gm-Message-State: AOAM530D0nRBx8HCs9N3KmbwX2KRxLWA4ayTSn/7kCyiZ0VvnEjECv8V kt77nujywyS53f/xEe/v6Cst/g== X-Google-Smtp-Source: ABdhPJycqhqp8fRGIUb3jRYRy+8x/MiJ9pPbNPYQD1G3WrU7BU6Yp5GlTMFR/KPoICRs6eJqoSqkUQ== X-Received: by 2002:a05:620a:a90:: with SMTP id v16mr2505177qkg.226.1602074650939; Wed, 07 Oct 2020 05:44:10 -0700 (PDT) Received: from ziepe.ca (hlfxns017vw-156-34-48-30.dhcp-dynamic.fibreop.ns.bellaliant.net. [156.34.48.30]) by smtp.gmail.com with ESMTPSA id d37sm1423421qta.76.2020.10.07.05.44.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 07 Oct 2020 05:44:10 -0700 (PDT) Received: from jgg by mlx with local (Exim 4.94) (envelope-from ) id 1kQ8nh-000tZ6-KI; Wed, 07 Oct 2020 09:44:09 -0300 Date: Wed, 7 Oct 2020 09:44:09 -0300 From: Jason Gunthorpe To: Marek Szyprowski Cc: Daniel Vetter , DRI Development , LKML , Daniel Vetter , Andrew Morton , John Hubbard , =?utf-8?B?SsOpcsO0bWU=?= Glisse , Jan Kara , Dan Williams , Linux MM , Linux ARM , Pawel Osciak , Kyungmin Park , Tomasz Figa , Inki Dae , Joonyoung Shim , Seung-Woo Kim , linux-samsung-soc , "open list:DMA BUFFER SHARING FRAMEWORK" , Oded Gabbay Subject: Re: [PATCH 2/2] mm/frame-vec: use FOLL_LONGTERM Message-ID: <20201007124409.GN5177@ziepe.ca> References: <20201002175303.390363-1-daniel.vetter@ffwll.ch> <20201002175303.390363-2-daniel.vetter@ffwll.ch> <20201002180603.GL9916@ziepe.ca> <20201002233118.GM9916@ziepe.ca> <725819e9-4f07-3f04-08f8-b6180406b339@samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <725819e9-4f07-3f04-08f8-b6180406b339@samsung.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Oct 07, 2020 at 02:33:56PM +0200, Marek Szyprowski wrote: > Well, it was in vb2_get_vma() function, but now I see that it has been > lost in fb639eb39154 and 6690c8c78c74 some time ago... There is no guarentee that holding a get on the file says anthing about the VMA. This needed to check that the file was some special kind of file that promised the VMA layout and file lifetime are connected. Also, cloning a VMA outside the mm world is just really bad. That would screw up many assumptions the drivers make. If it is all obsolete I say we hide it behind a default n config symbol and taint the kernel if anything uses it. Add a big comment above the follow_pfn to warn others away from this code. Jason 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 X-Spam-Level: X-Spam-Status: No, score=-4.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9A1C8C4363D for ; Wed, 7 Oct 2020 12:45:28 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D9ACA20789 for ; Wed, 7 Oct 2020 12:45:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="SLjYdG56"; dkim=fail reason="signature verification failed" (2048-bit key) header.d=ziepe.ca header.i=@ziepe.ca header.b="L3Snl2lK" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D9ACA20789 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ziepe.ca Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=sXoi0BxfZwCOUNZzUbDwZUduuqbgCXWXierpUHKPCH8=; b=SLjYdG56wpTRGg3wnt1Yu3hlR Oo0uAXnnvBTKh+2CsjN9dtOExS1yXY2Acw/A6JPz49Yp67IF0fqbge/GTpn5S/zqa56UKZCrlAZYB Hm5svWwILKQVt6WHAb3i6pbr/f7I3+wEXvCMAgIZpRxg0GpnXh4A6jIB97Cm50DD0zVOvjGipb/wA NXJ1S+4WSlqHExlqeb5mq0h4hf3OCNiW537HqGJeFVvLXpz/muQVsUrTVSxTHJIfaqWFox28PT7Sh 3EsLSRxqFNOJmhFTHiqbqwFVXFOy7yellLLt5A4fxiRM6JxdpkFV4BtqTbNp4VqVoEoyR8deeF5MB 2LVdf2WLA==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kQ8nn-00023I-Fp; Wed, 07 Oct 2020 12:44:15 +0000 Received: from mail-qk1-x741.google.com ([2607:f8b0:4864:20::741]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kQ8nk-000224-VI for linux-arm-kernel@lists.infradead.org; Wed, 07 Oct 2020 12:44:14 +0000 Received: by mail-qk1-x741.google.com with SMTP id c62so2483870qke.1 for ; Wed, 07 Oct 2020 05:44:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ziepe.ca; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=YHwK7fj40rs6RtWBfMsDdiNwOc6I5e7hiW0vaeAiWPE=; b=L3Snl2lKZ0Efotdw5H66ICtk7hAPeqPHl2yvT2hFObgLWAEy3EBTXL+OsvS8u/QndV Pj12VmdFi1Z+tf74AMThconTJmYhkFSDG8iZx1jlaA7Czeyr7poiFxBLjV1keUOmp1a1 r6jTl4FOE/mmJjXmQ3zxvk1dmo6U3QKzXB0dREWbZ5bVe5DnC2HmgHKbEjSJ6zySfOog R+kS8ezo1stmGnlupvsVnR3bPxmU38krpYm29D741/i3IkmlnAWe/GfJ9rN+yP8YE0dg cFJCTIqTz/UvPJG/mR+/5L+YhDdX7fqDJnzC1ZYlkGVtaAUiADgRS6KwWpAwdsPJXKnQ JC2g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=YHwK7fj40rs6RtWBfMsDdiNwOc6I5e7hiW0vaeAiWPE=; b=tJRUcSeck3AjqA2adOQoeWI4MyBiaadtrM2z55GTyuWL6CrO1I/K2GPxkpgDqNhQ1a mE4f2zP/L/GNkzNFWF/ctWxCuhKls8DQnbDL1FuwD/yKfIBWzkWTzb4p7n5pe5sKhjpP rv78AsBdPyq2FHTm+sucEWfmUMzMIBZNU6nvo9/k1WE7icdw0dBNy/b3TAVpiz6+uuaw evlvQXfGVghB8cU5TeFZa29TWPaxTtMiHJjxnz0fhds3Pje2UrezK9zwr7vqesg4KAep CCidey/Xj16ZSEokr3pPfSVdzOA28HXZJKETVEMTT+5A5LMZTUyjw8UjhqMhiL0unKo4 Pnqw== X-Gm-Message-State: AOAM5313J/gRjMvvYyi4LB/hcF0kk1U6pJ9+aoaMqIlFJZn7STQcrNbr ukzRGM/ikNTdozubJx5JnJygjA== X-Google-Smtp-Source: ABdhPJycqhqp8fRGIUb3jRYRy+8x/MiJ9pPbNPYQD1G3WrU7BU6Yp5GlTMFR/KPoICRs6eJqoSqkUQ== X-Received: by 2002:a05:620a:a90:: with SMTP id v16mr2505177qkg.226.1602074650939; Wed, 07 Oct 2020 05:44:10 -0700 (PDT) Received: from ziepe.ca (hlfxns017vw-156-34-48-30.dhcp-dynamic.fibreop.ns.bellaliant.net. [156.34.48.30]) by smtp.gmail.com with ESMTPSA id d37sm1423421qta.76.2020.10.07.05.44.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 07 Oct 2020 05:44:10 -0700 (PDT) Received: from jgg by mlx with local (Exim 4.94) (envelope-from ) id 1kQ8nh-000tZ6-KI; Wed, 07 Oct 2020 09:44:09 -0300 Date: Wed, 7 Oct 2020 09:44:09 -0300 From: Jason Gunthorpe To: Marek Szyprowski Subject: Re: [PATCH 2/2] mm/frame-vec: use FOLL_LONGTERM Message-ID: <20201007124409.GN5177@ziepe.ca> References: <20201002175303.390363-1-daniel.vetter@ffwll.ch> <20201002175303.390363-2-daniel.vetter@ffwll.ch> <20201002180603.GL9916@ziepe.ca> <20201002233118.GM9916@ziepe.ca> <725819e9-4f07-3f04-08f8-b6180406b339@samsung.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <725819e9-4f07-3f04-08f8-b6180406b339@samsung.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201007_084413_346507_F1CCDF01 X-CRM114-Status: GOOD ( 14.14 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Oded Gabbay , Inki Dae , linux-samsung-soc , Jan Kara , Joonyoung Shim , Pawel Osciak , Daniel Vetter , Seung-Woo Kim , LKML , DRI Development , Tomasz Figa , Kyungmin Park , Linux MM , =?utf-8?B?SsOpcsO0bWU=?= Glisse , John Hubbard , Daniel Vetter , Andrew Morton , Dan Williams , Linux ARM , "open list:DMA BUFFER SHARING FRAMEWORK" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Oct 07, 2020 at 02:33:56PM +0200, Marek Szyprowski wrote: > Well, it was in vb2_get_vma() function, but now I see that it has been > lost in fb639eb39154 and 6690c8c78c74 some time ago... There is no guarentee that holding a get on the file says anthing about the VMA. This needed to check that the file was some special kind of file that promised the VMA layout and file lifetime are connected. Also, cloning a VMA outside the mm world is just really bad. That would screw up many assumptions the drivers make. If it is all obsolete I say we hide it behind a default n config symbol and taint the kernel if anything uses it. Add a big comment above the follow_pfn to warn others away from this code. Jason _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel 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 X-Spam-Level: X-Spam-Status: No, score=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B88C4C41604 for ; Wed, 7 Oct 2020 15:40:06 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 4567D216C4 for ; Wed, 7 Oct 2020 15:40:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=ziepe.ca header.i=@ziepe.ca header.b="L3Snl2lK" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4567D216C4 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ziepe.ca Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id ED81B6E930; Wed, 7 Oct 2020 15:39:48 +0000 (UTC) Received: from mail-qk1-x741.google.com (mail-qk1-x741.google.com [IPv6:2607:f8b0:4864:20::741]) by gabe.freedesktop.org (Postfix) with ESMTPS id BED1089319 for ; Wed, 7 Oct 2020 12:44:11 +0000 (UTC) Received: by mail-qk1-x741.google.com with SMTP id y198so2489569qka.0 for ; Wed, 07 Oct 2020 05:44:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ziepe.ca; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=YHwK7fj40rs6RtWBfMsDdiNwOc6I5e7hiW0vaeAiWPE=; b=L3Snl2lKZ0Efotdw5H66ICtk7hAPeqPHl2yvT2hFObgLWAEy3EBTXL+OsvS8u/QndV Pj12VmdFi1Z+tf74AMThconTJmYhkFSDG8iZx1jlaA7Czeyr7poiFxBLjV1keUOmp1a1 r6jTl4FOE/mmJjXmQ3zxvk1dmo6U3QKzXB0dREWbZ5bVe5DnC2HmgHKbEjSJ6zySfOog R+kS8ezo1stmGnlupvsVnR3bPxmU38krpYm29D741/i3IkmlnAWe/GfJ9rN+yP8YE0dg cFJCTIqTz/UvPJG/mR+/5L+YhDdX7fqDJnzC1ZYlkGVtaAUiADgRS6KwWpAwdsPJXKnQ JC2g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=YHwK7fj40rs6RtWBfMsDdiNwOc6I5e7hiW0vaeAiWPE=; b=gCDAeuzdjow5xgNTGRibpqDQeP+YUleJrF5k4xpsqz+lP/OapEMs6o4Uy751kHuXu/ XTha+/qVXg2OrDgDT6YE1DttIh+eTxrptz0wGNUJ2We6BQ0mi2Q+vdn/i9CbVcEB+wRu AbhL5SxhuCd5kwnLEuOVb4Gt0rTMkyxJBCH09/uPf9Zf42SQ17yhw5C5CkwTFbh9h90k HrDpHMP92S3KYJ/9P2+Q6mWPaML4leM8Yg77zD8SWuoWsxg5etXbvZVSWuAPGQcsXZx2 OYIqk7ejuHtfc8IA8XqZINatO6ntZOgNDV1Kvx2vcw/ALtdS3SQLuK63PJX8xF+ugsdh tzrA== X-Gm-Message-State: AOAM531wtWF8+Tq02/CYt63vi4MYo7/nyBWhaXKbWFn9/cPMy3kTej5E EFtBDbVmYAP33dvksZPQ+E5OEg== X-Google-Smtp-Source: ABdhPJycqhqp8fRGIUb3jRYRy+8x/MiJ9pPbNPYQD1G3WrU7BU6Yp5GlTMFR/KPoICRs6eJqoSqkUQ== X-Received: by 2002:a05:620a:a90:: with SMTP id v16mr2505177qkg.226.1602074650939; Wed, 07 Oct 2020 05:44:10 -0700 (PDT) Received: from ziepe.ca (hlfxns017vw-156-34-48-30.dhcp-dynamic.fibreop.ns.bellaliant.net. [156.34.48.30]) by smtp.gmail.com with ESMTPSA id d37sm1423421qta.76.2020.10.07.05.44.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 07 Oct 2020 05:44:10 -0700 (PDT) Received: from jgg by mlx with local (Exim 4.94) (envelope-from ) id 1kQ8nh-000tZ6-KI; Wed, 07 Oct 2020 09:44:09 -0300 Date: Wed, 7 Oct 2020 09:44:09 -0300 From: Jason Gunthorpe To: Marek Szyprowski Subject: Re: [PATCH 2/2] mm/frame-vec: use FOLL_LONGTERM Message-ID: <20201007124409.GN5177@ziepe.ca> References: <20201002175303.390363-1-daniel.vetter@ffwll.ch> <20201002175303.390363-2-daniel.vetter@ffwll.ch> <20201002180603.GL9916@ziepe.ca> <20201002233118.GM9916@ziepe.ca> <725819e9-4f07-3f04-08f8-b6180406b339@samsung.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <725819e9-4f07-3f04-08f8-b6180406b339@samsung.com> X-Mailman-Approved-At: Wed, 07 Oct 2020 15:39:39 +0000 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: , Cc: linux-samsung-soc , Jan Kara , Joonyoung Shim , Pawel Osciak , Daniel Vetter , Seung-Woo Kim , LKML , DRI Development , Tomasz Figa , Kyungmin Park , Linux MM , =?utf-8?B?SsOpcsO0bWU=?= Glisse , John Hubbard , Daniel Vetter , Andrew Morton , Dan Williams , Linux ARM , "open list:DMA BUFFER SHARING FRAMEWORK" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Wed, Oct 07, 2020 at 02:33:56PM +0200, Marek Szyprowski wrote: > Well, it was in vb2_get_vma() function, but now I see that it has been > lost in fb639eb39154 and 6690c8c78c74 some time ago... There is no guarentee that holding a get on the file says anthing about the VMA. This needed to check that the file was some special kind of file that promised the VMA layout and file lifetime are connected. Also, cloning a VMA outside the mm world is just really bad. That would screw up many assumptions the drivers make. If it is all obsolete I say we hide it behind a default n config symbol and taint the kernel if anything uses it. Add a big comment above the follow_pfn to warn others away from this code. Jason _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel