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 7AD7CC76188 for ; Fri, 19 Jul 2019 04:26:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4A9242173B for ; Fri, 19 Jul 2019 04:26:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563510368; bh=FCsMAB1Le3dbb95jMq3Ii7C9GcLfcQ3xoI0XX/azHDM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=NZ31tLKjF6NPECXF2JbJTafKxx9TC2YqKsbcKVh/9uZ7l5B3GIVY8AJuJKalOw5ds 1cTCpKnTkPOCOpOui1eaJjHsy0tneiMgi3oy6Np0KKFZLr757x0yijKrxfy5my95+3 /4RnE08rODX7Sg9BKuzqBaxTrLas3G3xun7hv388= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733130AbfGSEIf (ORCPT ); Fri, 19 Jul 2019 00:08:35 -0400 Received: from mail.kernel.org ([198.145.29.99]:42844 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727046AbfGSEIa (ORCPT ); Fri, 19 Jul 2019 00:08:30 -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 0B6AB218A4; Fri, 19 Jul 2019 04:08:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563509309; bh=FCsMAB1Le3dbb95jMq3Ii7C9GcLfcQ3xoI0XX/azHDM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=RLqkxekKC0vfF+OEkKHdwwvrkbCOGEMK6nJWp6DEifl1TY+prHnJ928PRVTQyiLwG eLTill5aWOSDx+TMHCoj3wVo5YZUdVuVDzuGVfAjlxzS3dLLBi/56KXkfwFnzINBSy Ty30lEpYcpiXNAmkKgvaF3fcIbpB7o8Mq+2Zudm8= 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 4.19 027/101] drm/virtio: Add memory barriers for capset cache. Date: Fri, 19 Jul 2019 00:06:18 -0400 Message-Id: <20190719040732.17285-27-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190719040732.17285-1-sashal@kernel.org> References: <20190719040732.17285-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 7bdf6f0e58a5..8d2f5ded86d6 100644 --- a/drivers/gpu/drm/virtio/virtgpu_ioctl.c +++ b/drivers/gpu/drm/virtio/virtgpu_ioctl.c @@ -528,6 +528,9 @@ 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 020070d483d3..c8a581b1f4c4 100644 --- a/drivers/gpu/drm/virtio/virtgpu_vq.c +++ b/drivers/gpu/drm/virtio/virtgpu_vq.c @@ -588,6 +588,8 @@ 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