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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 04D9AC433FE for ; Fri, 10 Dec 2021 13:14:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241616AbhLJNR6 (ORCPT ); Fri, 10 Dec 2021 08:17:58 -0500 Received: from szxga01-in.huawei.com ([45.249.212.187]:15724 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233989AbhLJNRz (ORCPT ); Fri, 10 Dec 2021 08:17:55 -0500 Received: from kwepemi100009.china.huawei.com (unknown [172.30.72.54]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4J9WWK4tBQzZdVx; Fri, 10 Dec 2021 21:11:25 +0800 (CST) Received: from kwepemm600016.china.huawei.com (7.193.23.20) by kwepemi100009.china.huawei.com (7.221.188.242) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.20; Fri, 10 Dec 2021 21:14:19 +0800 Received: from localhost.localdomain (10.67.165.24) by kwepemm600016.china.huawei.com (7.193.23.20) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.20; Fri, 10 Dec 2021 21:14:18 +0800 From: Guangbin Huang To: , , CC: , , , , Subject: [PATCH net 2/2] net: hns3: fix race condition in debugfs Date: Fri, 10 Dec 2021 21:09:34 +0800 Message-ID: <20211210130934.36278-3-huangguangbin2@huawei.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20211210130934.36278-1-huangguangbin2@huawei.com> References: <20211210130934.36278-1-huangguangbin2@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.67.165.24] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To kwepemm600016.china.huawei.com (7.193.23.20) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Yufeng Mo When multiple threads concurrently access the debugfs content, data and pointer exceptions may occur. Therefore, mutex lock protection is added for debugfs. Fixes: 5e69ea7ee2a6 ("net: hns3: refactor the debugfs process") Signed-off-by: Yufeng Mo Signed-off-by: Guangbin Huang --- drivers/net/ethernet/hisilicon/hns3/hnae3.h | 2 ++ .../ethernet/hisilicon/hns3/hns3_debugfs.c | 20 +++++++++++++------ 2 files changed, 16 insertions(+), 6 deletions(-) diff --git a/drivers/net/ethernet/hisilicon/hns3/hnae3.h b/drivers/net/ethernet/hisilicon/hns3/hnae3.h index 3f7a9a4c59d5..63f5abcc6bf4 100644 --- a/drivers/net/ethernet/hisilicon/hns3/hnae3.h +++ b/drivers/net/ethernet/hisilicon/hns3/hnae3.h @@ -839,6 +839,8 @@ struct hnae3_handle { u8 netdev_flags; struct dentry *hnae3_dbgfs; + /* protects concurrent contention between debugfs commands */ + struct mutex dbgfs_lock; /* Network interface message level enabled bits */ u32 msg_enable; diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_debugfs.c b/drivers/net/ethernet/hisilicon/hns3/hns3_debugfs.c index 081295bff765..c381f8af67f0 100644 --- a/drivers/net/ethernet/hisilicon/hns3/hns3_debugfs.c +++ b/drivers/net/ethernet/hisilicon/hns3/hns3_debugfs.c @@ -1226,6 +1226,7 @@ static ssize_t hns3_dbg_read(struct file *filp, char __user *buffer, if (ret) return ret; + mutex_lock(&handle->dbgfs_lock); save_buf = &hns3_dbg_cmd[index].buf; if (!test_bit(HNS3_NIC_STATE_INITED, &priv->state) || @@ -1238,15 +1239,15 @@ static ssize_t hns3_dbg_read(struct file *filp, char __user *buffer, read_buf = *save_buf; } else { read_buf = kvzalloc(hns3_dbg_cmd[index].buf_len, GFP_KERNEL); - if (!read_buf) - return -ENOMEM; + if (!read_buf) { + ret = -ENOMEM; + goto out; + } /* save the buffer addr until the last read operation */ *save_buf = read_buf; - } - /* get data ready for the first time to read */ - if (!*ppos) { + /* get data ready for the first time to read */ ret = hns3_dbg_read_cmd(dbg_data, hns3_dbg_cmd[index].cmd, read_buf, hns3_dbg_cmd[index].buf_len); if (ret) @@ -1255,8 +1256,10 @@ static ssize_t hns3_dbg_read(struct file *filp, char __user *buffer, size = simple_read_from_buffer(buffer, count, ppos, read_buf, strlen(read_buf)); - if (size > 0) + if (size > 0) { + mutex_unlock(&handle->dbgfs_lock); return size; + } out: /* free the buffer for the last read operation */ @@ -1265,6 +1268,7 @@ static ssize_t hns3_dbg_read(struct file *filp, char __user *buffer, *save_buf = NULL; } + mutex_unlock(&handle->dbgfs_lock); return ret; } @@ -1337,6 +1341,8 @@ int hns3_dbg_init(struct hnae3_handle *handle) debugfs_create_dir(hns3_dbg_dentry[i].name, handle->hnae3_dbgfs); + mutex_init(&handle->dbgfs_lock); + for (i = 0; i < ARRAY_SIZE(hns3_dbg_cmd); i++) { if ((hns3_dbg_cmd[i].cmd == HNAE3_DBG_CMD_TM_NODES && ae_dev->dev_version <= HNAE3_DEVICE_VERSION_V2) || @@ -1363,6 +1369,7 @@ int hns3_dbg_init(struct hnae3_handle *handle) return 0; out: + mutex_destroy(&handle->dbgfs_lock); debugfs_remove_recursive(handle->hnae3_dbgfs); handle->hnae3_dbgfs = NULL; return ret; @@ -1378,6 +1385,7 @@ void hns3_dbg_uninit(struct hnae3_handle *handle) hns3_dbg_cmd[i].buf = NULL; } + mutex_destroy(&handle->dbgfs_lock); debugfs_remove_recursive(handle->hnae3_dbgfs); handle->hnae3_dbgfs = NULL; } -- 2.33.0