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=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 0E283C43381 for ; Mon, 18 Mar 2019 09:29:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CF42F2075C for ; Mon, 18 Mar 2019 09:29:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1552901374; bh=ucODM53MYhIx0yQbjAVYzFivSWf09l9qxNPDe8C15D8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=sIxatRIUI/GIaWTK6ju7ZQMPzpOLFqbUK4TJ4tgg1M0xG7ZMnuFH6yLIei18A6arm ZcATiCbncC8LiLNSczzukGzGq8g9ZjoTRj//U4piW3A1hdbmNgvdRMskRYnG7x/JLg y54xWG5xjRaC/PUIDQ/B7n091AyBcdy71Hkr51WI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728247AbfCRJ3d (ORCPT ); Mon, 18 Mar 2019 05:29:33 -0400 Received: from mail.kernel.org ([198.145.29.99]:35888 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728236AbfCRJ33 (ORCPT ); Mon, 18 Mar 2019 05:29:29 -0400 Received: from localhost (5356596B.cm-6-7b.dynamic.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 AA12B2075C; Mon, 18 Mar 2019 09:29:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1552901368; bh=ucODM53MYhIx0yQbjAVYzFivSWf09l9qxNPDe8C15D8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=dOzQle62A4If1Skxy1erXnHYrsjwYX9piU5w15HyNPQ4pM/LXtC3qyWhuaIvy3R6u mdrHqDlkO54/pWyWHI/lcnrTkBeD1WSkAN1HncWKcGULx/63d23IjXaREgibmfJfFn 2ekzK/sLclKxEWDyfr0pvhXstdi6VB3edvpsSQwI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jack Morgenstein , Tariq Toukan , "David S. Miller" Subject: [PATCH 4.20 24/52] net/mlx4_core: Fix locking in SRIOV mode when switching between events and polling Date: Mon, 18 Mar 2019 10:25:11 +0100 Message-Id: <20190318083846.314312550@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190318083843.398913295@linuxfoundation.org> References: <20190318083843.398913295@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore 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 4.20-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jack Morgenstein [ Upstream commit c07d27927f2f2e96fcd27bb9fb330c9ea65612d0 ] In procedures mlx4_cmd_use_events() and mlx4_cmd_use_polling(), we need to guarantee that there are no FW commands in progress on the comm channel (for VFs) or wrapped FW commands (on the PF) when SRIOV is active. We do this by also taking the slave_cmd_mutex when SRIOV is active. This is especially important when switching from event to polling, since we free the command-context array during the switch. If there are FW commands in progress (e.g., waiting for a completion event), the completion event handler will access freed memory. Since the decision to use comm_wait or comm_poll is taken before grabbing the event_sem/poll_sem in mlx4_comm_cmd_wait/poll, we must take the slave_cmd_mutex as well (to guarantee that the decision to use events or polling and the call to the appropriate cmd function are atomic). Fixes: a7e1f04905e5 ("net/mlx4_core: Fix deadlock when switching between polling and event fw commands") Signed-off-by: Jack Morgenstein Signed-off-by: Tariq Toukan Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/mellanox/mlx4/cmd.c | 8 ++++++++ 1 file changed, 8 insertions(+) --- a/drivers/net/ethernet/mellanox/mlx4/cmd.c +++ b/drivers/net/ethernet/mellanox/mlx4/cmd.c @@ -2645,6 +2645,8 @@ int mlx4_cmd_use_events(struct mlx4_dev if (!priv->cmd.context) return -ENOMEM; + if (mlx4_is_mfunc(dev)) + mutex_lock(&priv->cmd.slave_cmd_mutex); down_write(&priv->cmd.switch_sem); for (i = 0; i < priv->cmd.max_cmds; ++i) { priv->cmd.context[i].token = i; @@ -2670,6 +2672,8 @@ int mlx4_cmd_use_events(struct mlx4_dev down(&priv->cmd.poll_sem); priv->cmd.use_events = 1; up_write(&priv->cmd.switch_sem); + if (mlx4_is_mfunc(dev)) + mutex_unlock(&priv->cmd.slave_cmd_mutex); return err; } @@ -2682,6 +2686,8 @@ void mlx4_cmd_use_polling(struct mlx4_de struct mlx4_priv *priv = mlx4_priv(dev); int i; + if (mlx4_is_mfunc(dev)) + mutex_lock(&priv->cmd.slave_cmd_mutex); down_write(&priv->cmd.switch_sem); priv->cmd.use_events = 0; @@ -2693,6 +2699,8 @@ void mlx4_cmd_use_polling(struct mlx4_de up(&priv->cmd.poll_sem); up_write(&priv->cmd.switch_sem); + if (mlx4_is_mfunc(dev)) + mutex_unlock(&priv->cmd.slave_cmd_mutex); } struct mlx4_cmd_mailbox *mlx4_alloc_cmd_mailbox(struct mlx4_dev *dev)