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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,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 A0E0FC433FF for ; Mon, 29 Jul 2019 20:09:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 672402064C for ; Mon, 29 Jul 2019 20:09:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564430993; bh=ZGWD3sUV9uHaEwmTx4a0VLY6cZXDAmvPWcFM/D4w6YY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=jpBHlAWqUvEUwMcOvLRvTPLcqRkInRlbwF88XvjnxDdmVJUWmLIIUUBDngeE3vx27 IoV01JsEYQZbHsHkLd8235SQSU04f69P/Zt1UwBVghomX9pg2cgmvMdaYIdYTrxlcy nyBJLghrYXjs2nkhIrgk06iESwX+xa9bdQm1X83E= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730405AbfG2UJw (ORCPT ); Mon, 29 Jul 2019 16:09:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:50064 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729794AbfG2Tfn (ORCPT ); Mon, 29 Jul 2019 15:35:43 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id CCA3A217D4; Mon, 29 Jul 2019 19:35:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564428943; bh=ZGWD3sUV9uHaEwmTx4a0VLY6cZXDAmvPWcFM/D4w6YY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=V5i5i2i0fEWv/G/6K3NhQdsdlqW7iUTehHXyDkQAEUN7mlDEp4vQ/3WX31LTae1rd GBWOlwDt9TgpKIRA0+OHiAeU/wHfBxMWx8bTqxncsGpmrTM2iDs3DZJ5Wfg8i5+Brq 5GRuUdybzOft9wInMXPWSKZY6Sza/QLrNaHpfSbM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, David Riley , Gerd Hoffmann , Sasha Levin Subject: [PATCH 4.14 236/293] drm/virtio: Add memory barriers for capset cache. Date: Mon, 29 Jul 2019 21:22:07 +0200 Message-Id: <20190729190842.535102914@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190729190820.321094988@linuxfoundation.org> References: <20190729190820.321094988@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [ 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 ed9c443bb8a1..40cc2f6707cf 100644 --- a/drivers/gpu/drm/virtio/virtgpu_ioctl.c +++ b/drivers/gpu/drm/virtio/virtgpu_ioctl.c @@ -523,6 +523,9 @@ static int virtio_gpu_get_caps_ioctl(struct drm_device *dev, ret = wait_event_timeout(vgdev->resp_wq, atomic_read(&cache_ent->is_valid), 5 * HZ); + /* 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 26a2da1f712d..21c2de81f3e3 100644 --- a/drivers/gpu/drm/virtio/virtgpu_vq.c +++ b/drivers/gpu/drm/virtio/virtgpu_vq.c @@ -585,6 +585,8 @@ 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