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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 051F8C76188 for ; Fri, 19 Jul 2019 04:39:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D3BE62077C for ; Fri, 19 Jul 2019 04:39:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563511164; bh=J8yg1JMnlCbaWL6cdq7le4aMJLf01ArsHpijP5jmHeI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=gJ5V9oMbuQgIK2bpGa1ef3PZRmsM85WBIPSEeyzjZFUes55gRs0TmYd5h8e0sCb84 Lh/fzT6OFwDG7/BR9hX+cRJT+M/OVKVAZvx7DCSUSWc9vms/v66CC0Lz5VH+/lKNBi HdPk6dqvJXPpiE7fBcuSWXMcobHOmilqIxgJxqts= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727124AbfGSD6t (ORCPT ); Thu, 18 Jul 2019 23:58:49 -0400 Received: from mail.kernel.org ([198.145.29.99]:58158 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727016AbfGSD6q (ORCPT ); Thu, 18 Jul 2019 23:58:46 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7064D21873; Fri, 19 Jul 2019 03:58:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563508726; bh=J8yg1JMnlCbaWL6cdq7le4aMJLf01ArsHpijP5jmHeI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UNUSlW4LxU7CDYItQ9E9EPQk7r2o+O8PTuEOLFOYtfy8bNNIlRycrlIPdhgePMEq5 I8dsbW46pbhBP+ZmqUveEjwjx9/GwS4kHF5s3lMoluv6OXiqCZkV2ubM07br55MFE3 Qeofr3/vy0HUwG1GDgOjmON793B33uvP/22Iqi30= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: David Riley , Gerd Hoffmann , Sasha Levin , dri-devel@lists.freedesktop.org, virtualization@lists.linux-foundation.org Subject: [PATCH AUTOSEL 5.2 054/171] drm/virtio: Add memory barriers for capset cache. Date: Thu, 18 Jul 2019 23:54:45 -0400 Message-Id: <20190719035643.14300-54-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190719035643.14300-1-sashal@kernel.org> References: <20190719035643.14300-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: David Riley [ Upstream commit 9ff3a5c88e1f1ab17a31402b96d45abe14aab9d7 ] After data is copied to the cache entry, atomic_set is used indicate that the data is the entry is valid without appropriate memory barriers. Similarly the read side was missing the corresponding memory barriers. Signed-off-by: David Riley Link: http://patchwork.freedesktop.org/patch/msgid/20190610211810.253227-5-davidriley@chromium.org Signed-off-by: Gerd Hoffmann Signed-off-by: Sasha Levin --- drivers/gpu/drm/virtio/virtgpu_ioctl.c | 3 +++ drivers/gpu/drm/virtio/virtgpu_vq.c | 2 ++ 2 files changed, 5 insertions(+) diff --git a/drivers/gpu/drm/virtio/virtgpu_ioctl.c b/drivers/gpu/drm/virtio/virtgpu_ioctl.c index 949a264985fc..19fbffd0f7a3 100644 --- a/drivers/gpu/drm/virtio/virtgpu_ioctl.c +++ b/drivers/gpu/drm/virtio/virtgpu_ioctl.c @@ -542,6 +542,9 @@ static int virtio_gpu_get_caps_ioctl(struct drm_device *dev, if (!ret) return -EBUSY; + /* is_valid check must proceed before copy of the cache entry. */ + smp_rmb(); + ptr = cache_ent->caps_cache; copy_exit: diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c index 5bb0f0a084e9..a7684f9c80db 100644 --- a/drivers/gpu/drm/virtio/virtgpu_vq.c +++ b/drivers/gpu/drm/virtio/virtgpu_vq.c @@ -583,6 +583,8 @@ static void virtio_gpu_cmd_capset_cb(struct virtio_gpu_device *vgdev, cache_ent->id == le32_to_cpu(cmd->capset_id)) { memcpy(cache_ent->caps_cache, resp->capset_data, cache_ent->size); + /* Copy must occur before is_valid is signalled. */ + smp_wmb(); atomic_set(&cache_ent->is_valid, 1); break; } -- 2.20.1