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 8C789C4363A for ; Mon, 26 Oct 2020 10:59:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4FD362225C for ; Mon, 26 Oct 2020 10:59:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ffwll.ch header.i=@ffwll.ch header.b="BE6oxOGm" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1772822AbgJZK6m (ORCPT ); Mon, 26 Oct 2020 06:58:42 -0400 Received: from mail-wr1-f67.google.com ([209.85.221.67]:41191 "EHLO mail-wr1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1772795AbgJZK6k (ORCPT ); Mon, 26 Oct 2020 06:58:40 -0400 Received: by mail-wr1-f67.google.com with SMTP id s9so11842939wro.8 for ; Mon, 26 Oct 2020 03:58:39 -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=fFEiUvLl06c3j38++d5NzLL6L7leWWZ4E8u91rYq/3A=; b=BE6oxOGm6LpmFehTBcLW4JPuAVn0ztXRRhPFdKmp1PBfZHMfOH6ZZMUim7N+RidGFG 0CE8UiBULFscc13H0ar8GrDLO4yJ1P0bnnkFlnldicZz6vS1PSOwsA2+DLJdMtAv2h85 Tg25hld8e9Oy330GCD/SQEbTeh0mowIk6eEfA= 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=fFEiUvLl06c3j38++d5NzLL6L7leWWZ4E8u91rYq/3A=; b=esPnso5D9NK1h0bG+krPSWLOGF0HRbF9tiBqNennILw+E7A8vGly/cDgklc7QvIpSH phkma1MEtbBC43/TMOt0sso4LgJ8g2XYB0bi/0DfI1ktG94l8S4/nIMZy4+ZHQiNHGyr 6L4Djb7i3y8AezgIYB1QV2CLzJGo1oO+8UNOARv2erbwtRr9UQCKo6GRiSAHqGtnfmCU YSYplw7JXR9qPLxwTfJa4yIlyslWK4CcMn7MJnvCkDZMVv9HLHtLNBihiNFOFAo5YM07 zKyOodduvxc6MszhLY3q4C7WV/J4lk/xWbQiqE+MhSWUBrkLFE50+PT17JVx4GyLnb2F 5dgw== X-Gm-Message-State: AOAM533kZBXr1WMxcY45XYjuX+yTH4cIoXrgbjIe4zEbJ57GLMMB1eV2 5YBQj510AoI1WRpcSfFRKPuHlU8dFx1Zs8z9 X-Google-Smtp-Source: ABdhPJyJPBqr4xzE4feUIHJFFKeriugShRo0uGRtLd+TVzcLzKKWgkZaYccYEU5/Oo10Zk0lMDMkEw== X-Received: by 2002:a05:6000:12c9:: with SMTP id l9mr16792055wrx.309.1603709918272; Mon, 26 Oct 2020 03:58:38 -0700 (PDT) Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id w83sm21165156wmg.48.2020.10.26.03.58.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 26 Oct 2020 03:58:37 -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 Subject: [PATCH v4 09/15] media/videbuf1|2: Mark follow_pfn usage as unsafe Date: Mon, 26 Oct 2020 11:58:12 +0100 Message-Id: <20201026105818.2585306-10-daniel.vetter@ffwll.ch> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201026105818.2585306-1-daniel.vetter@ffwll.ch> References: <20201026105818.2585306-1-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: kvm@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