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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1DB80C433FE for ; Wed, 23 Nov 2022 16:27:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236692AbiKWQ1C (ORCPT ); Wed, 23 Nov 2022 11:27:02 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51504 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238511AbiKWQ0w (ORCPT ); Wed, 23 Nov 2022 11:26:52 -0500 Received: from mail-qk1-x729.google.com (mail-qk1-x729.google.com [IPv6:2607:f8b0:4864:20::729]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C56328F3EF for ; Wed, 23 Nov 2022 08:26:51 -0800 (PST) Received: by mail-qk1-x729.google.com with SMTP id v8so12755122qkg.12 for ; Wed, 23 Nov 2022 08:26:51 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ziepe.ca; s=google; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date:from:to :cc:subject:date:message-id:reply-to; bh=MVWe1KbwH32KSdOuQUG2Cu353SfSlMLZuLamaD0dXtw=; b=Np4/bmkbkzbftxGu4Xfe3xPQnjtFBVjVs43hK0IMuIqj9d2b1aoHPdKTK7d9Ke8toz vOgB2vyRSUHIOeOu08dhDULtwQ5j+Nbp3OXGGHP8uw0vYLcrZi8vWive1qZKcSt9hoRV jFsR4rVjQqfhTeGYX8ZG5pyjJ3Eg2qkFKwYOYV1JnyWVyaKQd5Rmsk3g9LEj/9JeMwHW amUNSpUWJBWWt+UHDSHxKcCBFghFqojIUB4o8Z7v5GEjrMyNSaiD1O7YOJziZes7RGDa +2zg/YESx8k6j6m/4J/9pN9kTb9ioXiCa5Zk1vAlP3lGUhhmojae4twzM8At5SJfTPkR FaYw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=MVWe1KbwH32KSdOuQUG2Cu353SfSlMLZuLamaD0dXtw=; b=jbvUC0Dyy+UQjelwMX0EbDrIqe7hwkHbsOQBTNon8q74zsGvcLlyVJ3ny5Ky2Ntxd0 p1YNIUEVuAUILOcICqmzPY177Y5Ru1ghy4ud87NOQAk7KnUWyrmQRw5dx1vA5NQrThOb DeCRWgE5bBDD5ok2mU2/vMeJpklYW36m5Kg1AbMN1rsNNyZraP7WfwxHVVBFu7J4ahAc i0S3i8TRj/6sMzLOT6e2DKBeMnNAWbLljt9tQcspn4AbKP3iQPP0j9A1vghi/JObJGTp Mpd47bULCSnbtLnYLR93n4shYEbK8PM6eTudKm755IrGJoXKWhfsfFoaS7ww2J7T5jhj Vutg== X-Gm-Message-State: ANoB5pmzCihBbL90epSoMADbikIAJT5V+FtJAFKNDUgqxi3IAK9UUs2z N9Gs6JrmyOKFSnXn/RoWIGjIhOmwg6IenA== X-Google-Smtp-Source: AA0mqf4OyB3Ehnx6E7JWKWLmbM/ehJ6uXDD6TAq7u3b6JJ9+PO7nvAjKFynqi4t74Jyi+NjK8gQVJQ== X-Received: by 2002:a05:620a:2795:b0:6ec:51cd:c376 with SMTP id g21-20020a05620a279500b006ec51cdc376mr22947878qkp.300.1669220810961; Wed, 23 Nov 2022 08:26:50 -0800 (PST) Received: from ziepe.ca (hlfxns017vw-47-55-122-23.dhcp-dynamic.fibreop.ns.bellaliant.net. [47.55.122.23]) by smtp.gmail.com with ESMTPSA id q25-20020a05620a2a5900b006ee7923c187sm12521991qkp.42.2022.11.23.08.26.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 23 Nov 2022 08:26:50 -0800 (PST) Received: from jgg by wakko with local (Exim 4.95) (envelope-from ) id 1oxsaH-00AONK-SY; Wed, 23 Nov 2022 12:26:49 -0400 Date: Wed, 23 Nov 2022 12:26:49 -0400 From: Jason Gunthorpe To: Christian =?utf-8?B?S8O2bmln?= Cc: Daniel Vetter , DRI Development , Intel Graphics Development , Thomas Zimmermann , Suren Baghdasaryan , Matthew Wilcox , John Stultz , Daniel Vetter , Sumit Semwal , linux-media@vger.kernel.org, linaro-mm-sig@lists.linaro.org Subject: Re: [Linaro-mm-sig] Re: [PATCH] dma-buf: Require VM_PFNMAP vma for mmap Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org On Wed, Nov 23, 2022 at 04:15:05PM +0100, Christian König wrote: > I have not the slightest idea how people got this impression, but I have > heard it so many time from so many different sources that there must be some > common cause to this. Is the maybe some book or tutorial how to sophisticate > break the kernel or something like this? > > Anyway as far as I can see only correct approach would be to use an MMU > notifier or more high level hmm_range_fault()+seq number. It already uses a mmu notifier, this is why I have no idea what the page ref is doing.. Jason