From patchwork Fri May 8 12:31:14 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 226286 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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham 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 9EF14C38A2A for ; Fri, 8 May 2020 12:39:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8089A2495F for ; Fri, 8 May 2020 12:39:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588941569; bh=kmNmrZ1d3mohTWvPW42p/d2bF0lo3g+Sq23zNkUFmSA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=DKJpMk+EgZ9LAxWx/woIe5KvFli6hZeVNd6CHzYGr8WsWP371etbRYhr5T6ALRSMe uarv7qpxnXarTSYbYlkzUnQWAEhvPiYGPNKo96m/txV/M8llIT/1zbDh5CG/y68jFe m/j3G0l2FvhxXCfDcAr2+ABiUG85rJfka22b1k1Q= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728580AbgEHMj1 (ORCPT ); Fri, 8 May 2020 08:39:27 -0400 Received: from mail.kernel.org ([198.145.29.99]:58778 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728578AbgEHMj1 (ORCPT ); Fri, 8 May 2020 08:39:27 -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 DDD5121835; Fri, 8 May 2020 12:39:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588941566; bh=kmNmrZ1d3mohTWvPW42p/d2bF0lo3g+Sq23zNkUFmSA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=prINQpetDZVL+YEmbGCDr5ITlTmpdwmIEaUO1bLOoGHG8i/cr4wJvcOZ0Fd+QpBja 56lLQSvVpjM/3fhSOoeHfGfnkUWZwPMo93C6S4MZJjubAr/W6tf7rm3QliCXyC4TpG vTsJoTARDYBSAujcf1NHAmj+yFsLDXHkh81rvufU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mohamad Haj Yahia , Saeed Mahameed , "David S. Miller" Subject: [PATCH 4.4 083/312] net/mlx5: Fix potential deadlock in command mode change Date: Fri, 8 May 2020 14:31:14 +0200 Message-Id: <20200508123130.387555764@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200508123124.574959822@linuxfoundation.org> References: <20200508123124.574959822@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Mohamad Haj Yahia commit 9cba4ebcf374c3772f6eb61f2d065294b2451b49 upstream. Call command completion handler in case of timeout when working in interrupts mode. Avoid flushing the commands workqueue after acquiring the semaphores to prevent a potential deadlock. Fixes: e126ba97dba9 ('mlx5: Add driver for Mellanox Connect-IB adapters') Signed-off-by: Mohamad Haj Yahia Signed-off-by: Saeed Mahameed Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/mellanox/mlx5/core/cmd.c | 79 ++++++++++---------------- 1 file changed, 33 insertions(+), 46 deletions(-) --- a/drivers/net/ethernet/mellanox/mlx5/core/cmd.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/cmd.c @@ -750,13 +750,13 @@ static int wait_func(struct mlx5_core_de if (cmd->mode == CMD_MODE_POLLING) { wait_for_completion(&ent->done); - err = ent->ret; - } else { - if (!wait_for_completion_timeout(&ent->done, timeout)) - err = -ETIMEDOUT; - else - err = 0; + } else if (!wait_for_completion_timeout(&ent->done, timeout)) { + ent->ret = -ETIMEDOUT; + mlx5_cmd_comp_handler(dev, 1UL << ent->idx); } + + err = ent->ret; + if (err == -ETIMEDOUT) { mlx5_core_warn(dev, "%s(0x%x) timeout. Will cause a leak of a command resource\n", mlx5_command_str(msg_to_opcode(ent->in)), @@ -817,28 +817,26 @@ static int mlx5_cmd_invoke(struct mlx5_c goto out_free; } - if (!callback) { - err = wait_func(dev, ent); - if (err == -ETIMEDOUT) - goto out; - - ds = ent->ts2 - ent->ts1; - op = be16_to_cpu(((struct mlx5_inbox_hdr *)in->first.data)->opcode); - if (op < ARRAY_SIZE(cmd->stats)) { - stats = &cmd->stats[op]; - spin_lock_irq(&stats->lock); - stats->sum += ds; - ++stats->n; - spin_unlock_irq(&stats->lock); - } - mlx5_core_dbg_mask(dev, 1 << MLX5_CMD_TIME, - "fw exec time for %s is %lld nsec\n", - mlx5_command_str(op), ds); - *status = ent->status; - free_cmd(ent); - } + if (callback) + goto out; - return err; + err = wait_func(dev, ent); + if (err == -ETIMEDOUT) + goto out_free; + + ds = ent->ts2 - ent->ts1; + op = be16_to_cpu(((struct mlx5_inbox_hdr *)in->first.data)->opcode); + if (op < ARRAY_SIZE(cmd->stats)) { + stats = &cmd->stats[op]; + spin_lock_irq(&stats->lock); + stats->sum += ds; + ++stats->n; + spin_unlock_irq(&stats->lock); + } + mlx5_core_dbg_mask(dev, 1 << MLX5_CMD_TIME, + "fw exec time for %s is %lld nsec\n", + mlx5_command_str(op), ds); + *status = ent->status; out_free: free_cmd(ent); @@ -1230,41 +1228,30 @@ err_dbg: return err; } -void mlx5_cmd_use_events(struct mlx5_core_dev *dev) +static void mlx5_cmd_change_mod(struct mlx5_core_dev *dev, int mode) { struct mlx5_cmd *cmd = &dev->cmd; int i; for (i = 0; i < cmd->max_reg_cmds; i++) down(&cmd->sem); - down(&cmd->pages_sem); - flush_workqueue(cmd->wq); - - cmd->mode = CMD_MODE_EVENTS; + cmd->mode = mode; up(&cmd->pages_sem); for (i = 0; i < cmd->max_reg_cmds; i++) up(&cmd->sem); } -void mlx5_cmd_use_polling(struct mlx5_core_dev *dev) +void mlx5_cmd_use_events(struct mlx5_core_dev *dev) { - struct mlx5_cmd *cmd = &dev->cmd; - int i; - - for (i = 0; i < cmd->max_reg_cmds; i++) - down(&cmd->sem); - - down(&cmd->pages_sem); - - flush_workqueue(cmd->wq); - cmd->mode = CMD_MODE_POLLING; + mlx5_cmd_change_mod(dev, CMD_MODE_EVENTS); +} - up(&cmd->pages_sem); - for (i = 0; i < cmd->max_reg_cmds; i++) - up(&cmd->sem); +void mlx5_cmd_use_polling(struct mlx5_core_dev *dev) +{ + mlx5_cmd_change_mod(dev, CMD_MODE_POLLING); } static void free_msg(struct mlx5_core_dev *dev, struct mlx5_cmd_msg *msg)