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=-5.8 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 1AD51C433E6 for ; Wed, 17 Mar 2021 08:05:06 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 59D4F64F8F for ; Wed, 17 Mar 2021 08:05:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 59D4F64F8F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ffwll.ch Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id B8FAF6B0071; Wed, 17 Mar 2021 04:05:04 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B061F6B0073; Wed, 17 Mar 2021 04:05:04 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 958636B0075; Wed, 17 Mar 2021 04:05:04 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0056.hostedemail.com [216.40.44.56]) by kanga.kvack.org (Postfix) with ESMTP id 753AC6B0071 for ; Wed, 17 Mar 2021 04:05:04 -0400 (EDT) Received: from smtpin27.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 36E24180AD82F for ; Wed, 17 Mar 2021 08:05:04 +0000 (UTC) X-FDA: 77928630528.27.2E7732B Received: from mail-oi1-f171.google.com (mail-oi1-f171.google.com [209.85.167.171]) by imf01.hostedemail.com (Postfix) with ESMTP id 6BA3C200039A for ; Wed, 17 Mar 2021 08:05:03 +0000 (UTC) Received: by mail-oi1-f171.google.com with SMTP id u6so33605827oic.2 for ; Wed, 17 Mar 2021 01:05:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=EI5qglqxsKAU/W0ZKYTsFSvZf8l0B/oXcoORkaxMSD8=; b=fb1VA654QtgBN7yjx24Vbsgr8qILHcsfU8IERmXJmGaXai7ib/t/sz/A2+trz33o9V +jZ2x+KTzIoXu9ur15pcoOP0mcety3wwVzOYYhW2IDGTduuc/R5KdINLJaadqXnV3Anw TPbRuol5s8uvpHLE2zkBMQ0iFY8Iob2xpapBI= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=EI5qglqxsKAU/W0ZKYTsFSvZf8l0B/oXcoORkaxMSD8=; b=HNfu0/ly40mTf/RBHZnanxlVtn99mJgFToC5mOztaapxbTAxi4/1Kfdz/q2JGUSWbP A6RZBh+l/hMS9BG3mHTR/1PxohVTL48KJoD8wpk18Nkhj8OZGgJt8YlaIc7fMfyp4Ofe NXo2eXoid7+ikdP+/mfAZ5xqRLiNiJVnXRC2AnMKTPLR6W/uNPpzWqtJkVpc6cnWv7Pf xSn/MBb6LecDTY+U/GWbDb4eejT8UOCEnrK0vHhwqIV0SVQd2swq/IoHg0uP99SeWC+r z8ZGPdbL7gH8e4275lDR8UHgTXRIR3Xt5Ar/wI4h0ANqo5pIE73J5qLbRtDsUBljDYiC Af9g== X-Gm-Message-State: AOAM532PyypLa+LT+fyWTnDda57Rnytyfy2GUy+cSkH++zFTnmKr8alN KgSsrMcMp5FapT5ppGCq4cQ7z+XbuKyR8Mto6MsHBA== X-Google-Smtp-Source: ABdhPJwZYNnRwoTd/kuED1Yfh8EqOUzOIuqMpTc+matmHqjzLk6Tn4x3yBWT0QFOmmnBuxIzgcZ9JwEdKsAutEEaYeo= X-Received: by 2002:aca:4188:: with SMTP id o130mr1878713oia.101.1615968301447; Wed, 17 Mar 2021 01:05:01 -0700 (PDT) MIME-Version: 1.0 References: <20210316153303.3216674-1-daniel.vetter@ffwll.ch> <20210316153303.3216674-3-daniel.vetter@ffwll.ch> <20210316154549.GA60450@infradead.org> <20210317072248.GA284559@infradead.org> In-Reply-To: <20210317072248.GA284559@infradead.org> From: Daniel Vetter Date: Wed, 17 Mar 2021 09:04:50 +0100 Message-ID: Subject: Re: [PATCH 2/3] media/videobuf1|2: Mark follow_pfn usage as unsafe To: Christoph Hellwig Cc: DRI Development , LKML , KVM list , Linux MM , Linux ARM , linux-samsung-soc , "open list:DMA BUFFER SHARING FRAMEWORK" , Tomasz Figa , Hans Verkuil , Daniel Vetter , Jason Gunthorpe , Kees Cook , Dan Williams , Andrew Morton , John Hubbard , "J??r??me Glisse" , Jan Kara , Pawel Osciak , Marek Szyprowski , Kyungmin Park , Laurent Dufour , Vlastimil Babka , Daniel Jordan , Michel Lespinasse Content-Type: text/plain; charset="UTF-8" X-Stat-Signature: xk4qprxfcyg1xqnct335pef1qjgjpxdb X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: 6BA3C200039A Received-SPF: none (ffwll.ch>: No applicable sender policy available) receiver=imf01; identity=mailfrom; envelope-from=""; helo=mail-oi1-f171.google.com; client-ip=209.85.167.171 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1615968303-306096 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Mar 17, 2021 at 8:22 AM Christoph Hellwig wrote: > On Tue, Mar 16, 2021 at 04:52:44PM +0100, Daniel Vetter wrote: > > My understanding is mostly, but with some objections. And I kinda > > don't want to let this die in a bikeshed and then not getting rid of > > follow_pfn as a result. There's enough people who acked this, and the > > full removal got some nack from Mauro iirc. > > Hmm, ok I must have missed that. I defintively prefer your series over > doing nothing, but killing the dead horse ASAP would be even better. I have a bunch of slow-burner things I need to fix in this area of driver mmaps vs get_user_/follow_ conflicts anyway, I'll add a note to put the horse out of it's misery in due time. We have a few problems still where things might get pinned or used where it really shouldn't be. Can I count that as an ack on the series? You've touched this quite a bit recently. Thanks, Daniel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch