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=-12.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 38C17C64E6A for ; Wed, 21 Oct 2020 08:58:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CB6EE223C6 for ; Wed, 21 Oct 2020 08:58:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ffwll.ch header.i=@ffwll.ch header.b="K873XhCK" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2441226AbgJUI6Y (ORCPT ); Wed, 21 Oct 2020 04:58:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41430 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2502353AbgJUI5T (ORCPT ); Wed, 21 Oct 2020 04:57:19 -0400 Received: from mail-wr1-x444.google.com (mail-wr1-x444.google.com [IPv6:2a00:1450:4864:20::444]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 65B82C0613D6 for ; Wed, 21 Oct 2020 01:57:18 -0700 (PDT) Received: by mail-wr1-x444.google.com with SMTP id x7so2156112wrl.3 for ; Wed, 21 Oct 2020 01:57:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=62xo6Yc+okj8E3g2nExt24JkphJyecIdIYx1MX/KcgQ=; b=K873XhCKhky8xYu7l9PH0L4vvRQ8W4kOqwGB7em4FSZU/FH2w3o/Fs6+QECyRAghOu 8q8OodzeuuFUxMzw/vVk1/yMCBxwVGl1BeYckPl4pNsKxDrGH6PmKMHuJ2X/ASVVgbzy 2gMkhgZs8aQVpZ+fDa84ImMGzU1FdBr7OgsW4= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=62xo6Yc+okj8E3g2nExt24JkphJyecIdIYx1MX/KcgQ=; b=E9rIIdrfsAlzjXWivgAqXplyUBZNe3CFoTi0WGXuez43yWN1R5MDTl9EuJw1UWVzEa uwxK4pQGeTndkq/+F0YNgbHlLM63+QotqeobH1UjPDnetZJbXIbQWKBl2DlNRRZctXui 8DGa2pOe7rrLGHgqKdmaZBiwAQsTIAuc7Wyi++DlhPVlBQ2eMKdswfY6gtePGs9M1Sk0 sh1y5VDJlRJhpcNd86RcTHGOsIVvdhU0tIPZUsm4QTHM1P+/OfXlAGlW0iTahXY4bzc7 LIIjG2QIkShFOQxG119mhLt1uOipFV0jVxyZK94ORUyJ3GfNGDqcUtCtGWsZ2TdpNX5u py6w== X-Gm-Message-State: AOAM530Ro9oNGWUPpUmaDLw2Uqm3dd+9tlxodIeD7JOjFDhXEvPFYHNA 5c0PvGewpcq6WOVwSEGlaSSoeA== X-Google-Smtp-Source: ABdhPJxBj+/fddzStMvRlNb0kPGellflBixkVVFjchw9D6JBYyFT9T4kixhMP79NqV0iv84nhiR1VA== X-Received: by 2002:a5d:480a:: with SMTP id l10mr3285006wrq.238.1603270637190; Wed, 21 Oct 2020 01:57:17 -0700 (PDT) Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id q8sm2675939wro.32.2020.10.21.01.57.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 21 Oct 2020 01:57:16 -0700 (PDT) From: Daniel Vetter To: DRI Development , LKML Cc: kvm@vger.kernel.org, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, linux-media@vger.kernel.org, linux-s390@vger.kernel.org, Daniel Vetter , Daniel Vetter , Jason Gunthorpe , Kees Cook , Dan Williams , Andrew Morton , John Hubbard , =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= , Jan Kara , Pawel Osciak , Marek Szyprowski , Kyungmin Park , Tomasz Figa , Laurent Dufour , Vlastimil Babka , Daniel Jordan , Michel Lespinasse , Daniel Vetter Subject: [PATCH v3 10/16] media/videbuf1|2: Mark follow_pfn usage as unsafe Date: Wed, 21 Oct 2020 10:56:49 +0200 Message-Id: <20201021085655.1192025-11-daniel.vetter@ffwll.ch> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201021085655.1192025-1-daniel.vetter@ffwll.ch> References: <20201021085655.1192025-1-daniel.vetter@ffwll.ch> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org The media model assumes that buffers are all preallocated, so that when a media pipeline is running we never miss a deadline because the buffers aren't allocated or available. This means we cannot fix the v4l follow_pfn usage through mmu_notifier, without breaking how this all works. The only real fix is to deprecate userptr support for VM_IO | VM_PFNMAP mappings and tell everyone to cut over to dma-buf memory sharing for zerocopy. userptr for normal memory will keep working as-is, this only affects the zerocopy userptr usage enabled in 50ac952d2263 ("[media] videobuf2-dma-sg: Support io userptr operations on io memory"). Signed-off-by: Daniel Vetter Cc: Jason Gunthorpe Cc: Kees Cook Cc: Dan Williams Cc: Andrew Morton Cc: John Hubbard Cc: Jérôme Glisse Cc: Jan Kara Cc: Dan Williams Cc: linux-mm@kvack.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-samsung-soc@vger.kernel.org Cc: linux-media@vger.kernel.org Cc: Pawel Osciak Cc: Marek Szyprowski Cc: Kyungmin Park Cc: Tomasz Figa Cc: Laurent Dufour Cc: Vlastimil Babka Cc: Daniel Jordan Cc: Michel Lespinasse Signed-off-by: Daniel Vetter -- v3: - Reference the commit that enabled the zerocopy userptr use case to make it abundandtly clear that this patch only affects that, and not normal memory userptr. The old commit message already explained that normal memory userptr is unaffected, but I guess that was not clear enough. --- drivers/media/common/videobuf2/frame_vector.c | 2 +- drivers/media/v4l2-core/videobuf-dma-contig.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/media/common/videobuf2/frame_vector.c b/drivers/media/common/videobuf2/frame_vector.c index 6590987c14bd..e630494da65c 100644 --- a/drivers/media/common/videobuf2/frame_vector.c +++ b/drivers/media/common/videobuf2/frame_vector.c @@ -69,7 +69,7 @@ int get_vaddr_frames(unsigned long start, unsigned int nr_frames, break; while (ret < nr_frames && start + PAGE_SIZE <= vma->vm_end) { - err = follow_pfn(vma, start, &nums[ret]); + err = unsafe_follow_pfn(vma, start, &nums[ret]); if (err) { if (ret == 0) ret = err; diff --git a/drivers/media/v4l2-core/videobuf-dma-contig.c b/drivers/media/v4l2-core/videobuf-dma-contig.c index 52312ce2ba05..821c4a76ab96 100644 --- a/drivers/media/v4l2-core/videobuf-dma-contig.c +++ b/drivers/media/v4l2-core/videobuf-dma-contig.c @@ -183,7 +183,7 @@ static int videobuf_dma_contig_user_get(struct videobuf_dma_contig_memory *mem, user_address = untagged_baddr; while (pages_done < (mem->size >> PAGE_SHIFT)) { - ret = follow_pfn(vma, user_address, &this_pfn); + ret = unsafe_follow_pfn(vma, user_address, &this_pfn); if (ret) break; -- 2.28.0