From patchwork Fri Nov 27 16:41:28 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Daniel Vetter X-Patchwork-Id: 69459 Received: from vger.kernel.org ([23.128.96.18]) by www.linuxtv.org with esmtp (Exim 4.92) (envelope-from ) id 1kigqD-00Cqiq-FI; Fri, 27 Nov 2020 16:43:26 +0000 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732032AbgK0Qmf (ORCPT + 1 other); Fri, 27 Nov 2020 11:42:35 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54074 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731892AbgK0QmS (ORCPT ); Fri, 27 Nov 2020 11:42:18 -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 BA94DC0617A7 for ; Fri, 27 Nov 2020 08:42:17 -0800 (PST) Received: by mail-wr1-x442.google.com with SMTP id z7so6207509wrn.3 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=pGsPGDSGw8jpxW0QTLvDG7CJ7nhliufzps6IHQXsyiZUWCnPckdd136V3Zap/yB3E1 bGssGQUkYztVZpmunw6A9BhmreCiCg5fBVk0ULXdStQBus5JPFPc+Whr1ajmH/l91q8z mcJTjFBPLWcoF9bIB8zdwNbTHY6Sg6SPHgiX1JZHMHInx+UNJwnWTjohSoqtqnWFAD8r QrOUZo1ieeludbLH4soePj5w0Vn/u4TrTUnsfpAT4P2iRkY/dvNDZFXOuoEGmld+OTV6 n93mmqF0VQJSdRjMO1hBY4SqzUMAOvr9RtgzCzEHmltZLCOPYTz/SZQhEtwqOcXyj5o4 r1gg== X-Gm-Message-State: AOAM532JnWOoptSXdfvxl44+MAZt3M+KIK1etl8Lgwth77m3Pqdw4dAz nUvBKea8IFOn3EfH4MUS+egH3A== 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?b?SsOpcsO0bWUgR2xpc3Nl?= , 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 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-LSpam-Score: -2.5 (--) X-LSpam-Report: No, score=-2.5 required=5.0 tests=BAYES_00=-1.9,DKIM_SIGNED=0.1,DKIM_VALID=-0.1,DKIM_VALID_AU=-0.1,HEADER_FROM_DIFFERENT_DOMAINS=0.5,MAILING_LIST_MULTI=-1 autolearn=ham autolearn_force=no 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 Acked-by: Hans Verkuil --- 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;