From patchwork Tue Mar 16 15:33:02 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Daniel Vetter X-Patchwork-Id: 403654 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=-18.8 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 950D8C433DB for ; Tue, 16 Mar 2021 15:34:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6FDFD650F4 for ; Tue, 16 Mar 2021 15:34:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238088AbhCPPdu (ORCPT ); Tue, 16 Mar 2021 11:33:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36886 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238101AbhCPPdQ (ORCPT ); Tue, 16 Mar 2021 11:33:16 -0400 Received: from mail-wm1-x334.google.com (mail-wm1-x334.google.com [IPv6:2a00:1450:4864:20::334]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BE49EC061763 for ; Tue, 16 Mar 2021 08:33:15 -0700 (PDT) Received: by mail-wm1-x334.google.com with SMTP id f22-20020a7bc8d60000b029010c024a1407so1709332wml.2 for ; Tue, 16 Mar 2021 08:33:15 -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=tAmsDn5BdzFpIsfSDcu5mIHmvLYc/wJQn0BecfxLgl0=; b=ME4sGumFgKYUCqwSU9ZCBXBRBDOTgxTwFtahv+NVAVJHr+fD8AUrznH+V7FRtA8gOj B+CFMjnx7WbKUqyhiMCsTbXLvmFggAn1SQaPCFAka4KTPpVgwdX/WNFBVl3rpTLAziJj STDnUtNyyxJvOuElf8oAxewCR7SdYgUMXzeAE= 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=tAmsDn5BdzFpIsfSDcu5mIHmvLYc/wJQn0BecfxLgl0=; b=W1KehDz2RDuV9WOnAncz/vLNmi+2Mfz+YU1lKV9RYdXn3E2qvOkwHHtwm0wjyVSOBs smp0fm5Pn/OkaVvKWJDDc7B6q93bL1gmgnLARQmNqlEgzE1syv2lvDDQydpkq98EIOwL NcH6lnnmQHOGHGQtIXEI63+QcCcjBnyn8hlq8ik5q1/LUCkRTtPyhlp2mr+jd3kW9TG2 kgIwi2VyR/OPEfuuURRlvCL6XgSR19brHQWeMn56aIfsDxd4Ve4Lgw2yyWk4P/UaJgoj 78VGV0v0vmlPZof6Nu4hooHtJBiLFtZOvEZ0p+/MTxqP+qbCjLT1v00msI304KBuPRF6 0f8Q== X-Gm-Message-State: AOAM530kiFNIRcodI5g5IH1RDbFgm11MLtzb2OAeN8DciIp7d0032qd5 /bMApKYpR/I6uflVzisMtQ54gA== X-Google-Smtp-Source: ABdhPJxdFzaSGBW2sfC8QBc+tMQBXV96M89NWylJdwfCrwV7xrFzVSLG4KZ9deIsLAWFmFnloMhjFw== X-Received: by 2002:a05:600c:4a06:: with SMTP id c6mr209965wmp.35.1615908794565; Tue, 16 Mar 2021 08:33:14 -0700 (PDT) Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id h22sm3985078wmb.36.2021.03.16.08.33.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 16 Mar 2021 08:33:14 -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, Daniel Vetter , Tomasz Figa , Hans Verkuil , Daniel Vetter , Jason Gunthorpe , Kees Cook , Dan Williams , Andrew Morton , John Hubbard , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Jan Kara , Pawel Osciak , Marek Szyprowski , Kyungmin Park , Laurent Dufour , Vlastimil Babka , Daniel Jordan , Michel Lespinasse Subject: [PATCH 2/3] media/videobuf1|2: Mark follow_pfn usage as unsafe Date: Tue, 16 Mar 2021 16:33:02 +0100 Message-Id: <20210316153303.3216674-3-daniel.vetter@ffwll.ch> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210316153303.3216674-1-daniel.vetter@ffwll.ch> References: <20210316153303.3216674-1-daniel.vetter@ffwll.ch> MIME-Version: 1.0 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 Acked-by: Hans Verkuil 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;