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=-18.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham 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 565C1C5519F for ; Fri, 27 Nov 2020 16:43:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 22764221F7 for ; Fri, 27 Nov 2020 16:43:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ffwll.ch header.i=@ffwll.ch header.b="UdfuUiyL" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731924AbgK0QmV (ORCPT ); Fri, 27 Nov 2020 11:42:21 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54078 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731896AbgK0QmU (ORCPT ); Fri, 27 Nov 2020 11:42:20 -0500 Received: from mail-wr1-x442.google.com (mail-wr1-x442.google.com [IPv6:2a00:1450:4864:20::442]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BAF55C061A04 for ; Fri, 27 Nov 2020 08:42:17 -0800 (PST) Received: by mail-wr1-x442.google.com with SMTP id 64so6184890wra.11 for ; Fri, 27 Nov 2020 08:42:17 -0800 (PST) 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=BPpebch13YhiVnp0IIh0dviRE5BWGvg35r91rkcoUQ8=; b=UdfuUiyL9zVaZNoEd7CmWhkKrdsSAuB1DVT5XHR7CrlA5nhTEWInYppse02PjPc4Yi DkuS7B3q4Hio3DsYDg2teg7Ek0grF7iXH0QJVpnAt2UFzSQvjdPZloVznrc9uuKp5tQx CYqnHkdUS14/phlJoRVmiyHTnRlL9+CubKHZI= 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=BPpebch13YhiVnp0IIh0dviRE5BWGvg35r91rkcoUQ8=; b=XzlwYOptQmZ+/MhYgVjH1s0YG2pSw9U+pmJxm/dIQ8hZ/F7Ai03EHR7gXtak1y5nAu Ut9/lg98Hs2P/ZWaw3okYbCH1ihGxHhBsm5iHD+DeCzZaAW6f5T4G0L8JocsqjBELIvb rTRxxS+dvzBbok3t6+om7UVzKn+B7PLfV4NbFS2umvvo99T3M25wDAw9o/ZydAkDLniI CPolD9LNY1yJH3UdpYCkI235EA5xiO3RtWH8O8nIjkbqD96RJoJGfDGza2fBjnobV8R+ Bt9+NzIChKVfQM0nJutlUP+x0UTsvijIPmcYgQe3dxlZnX7BXeaNCVyw2z7dvTopBAEp 7odg== X-Gm-Message-State: AOAM532z7yoHxElFCZx2Le26oOnmNbzuZg8t+FfQ0wmWgnYz8LwTJtGK L+O+2e7YqUa9ilSV/OaZBwr3Jg== X-Google-Smtp-Source: ABdhPJwltLkH2puoMeVCFF2UXvWx72I/GcJQreeDtvjC+4zw+NslU71KlUliAfGBAX9PdM/7rkM8Ag== X-Received: by 2002:adf:fd0d:: with SMTP id e13mr11431089wrr.85.1606495336488; Fri, 27 Nov 2020 08:42:16 -0800 (PST) Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id q12sm14859078wrx.86.2020.11.27.08.42.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 27 Nov 2020 08:42:15 -0800 (PST) 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, Daniel Vetter , Tomasz Figa , 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 , Laurent Dufour , Vlastimil Babka , Daniel Jordan , Michel Lespinasse Subject: [PATCH v7 14/17] media/videobuf1|2: Mark follow_pfn usage as unsafe Date: Fri, 27 Nov 2020 17:41:28 +0100 Message-Id: <20201127164131.2244124-15-daniel.vetter@ffwll.ch> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201127164131.2244124-1-daniel.vetter@ffwll.ch> References: <20201127164131.2244124-1-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-samsung-soc@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"). Acked-by: Tomasz Figa 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 a0e65481a201..1a82ec13ea00 100644 --- a/drivers/media/common/videobuf2/frame_vector.c +++ b/drivers/media/common/videobuf2/frame_vector.c @@ -70,7 +70,7 @@ 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; -- 2.29.2