From patchwork Thu Mar 4 15:24:50 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tetsuo Handa X-Patchwork-Id: 12116483 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 37E8BC4332D for ; Thu, 4 Mar 2021 15:27:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1DC4564FAA for ; Thu, 4 Mar 2021 15:27:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234510AbhCDP0p (ORCPT ); Thu, 4 Mar 2021 10:26:45 -0500 Received: from www262.sakura.ne.jp ([202.181.97.72]:61856 "EHLO www262.sakura.ne.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233113AbhCDP0Q (ORCPT ); Thu, 4 Mar 2021 10:26:16 -0500 Received: from fsav302.sakura.ne.jp (fsav302.sakura.ne.jp [153.120.85.133]) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTP id 124FP2pi030926; Fri, 5 Mar 2021 00:25:03 +0900 (JST) (envelope-from penguin-kernel@I-love.SAKURA.ne.jp) Received: from www262.sakura.ne.jp (202.181.97.72) by fsav302.sakura.ne.jp (F-Secure/fsigk_smtp/550/fsav302.sakura.ne.jp); Fri, 05 Mar 2021 00:25:02 +0900 (JST) X-Virus-Status: clean(F-Secure/fsigk_smtp/550/fsav302.sakura.ne.jp) Received: from localhost.localdomain (M106072142033.v4.enabler.ne.jp [106.72.142.33]) (authenticated bits=0) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTPSA id 124FOtn7030882 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Fri, 5 Mar 2021 00:25:02 +0900 (JST) (envelope-from penguin-kernel@I-love.SAKURA.ne.jp) From: Tetsuo Handa To: Valentina Manea , Shuah Khan , Greg Kroah-Hartman Cc: Arnd Bergmann , linux-usb@vger.kernel.org, Tetsuo Handa Subject: [PATCH v4 07/12] usb: usbip: preallocate kernel threads for consistent attach operation Date: Fri, 5 Mar 2021 00:24:50 +0900 Message-Id: <20210304152455.3685-8-penguin-kernel@I-love.SAKURA.ne.jp> X-Mailer: git-send-email 2.18.4 In-Reply-To: <20210304152455.3685-1-penguin-kernel@I-love.SAKURA.ne.jp> References: <20210304152455.3685-1-penguin-kernel@I-love.SAKURA.ne.jp> Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org All usbip modules are doing (1) socket lookup for ud->tcp_socket (2) kthread_create() for ud->tcp_{tx,rx} (3) get_task_struct() on ud->tcp_{tx,rx} if kthread_create() succeeded (4) wake_up_process() on ud->tcp_{tx,rx} if kthread_create() succeeded where (1) (2) (3) can be grouped as a common function. Since we can't overwrite ud->tcp_socket and ud->tcp_{tx,rx} without checking ud->status, define usbip_thread_info for holding temporary resources and introduce usbip_prepare_threads()/usbip_unprepare_threads() which respectively allocates/frees these temporary resources. (4) is done by usbip_prepare_threads() callers after checking ud->status. Tested-by: syzbot Signed-off-by: Tetsuo Handa --- drivers/usb/usbip/usbip_common.c | 50 ++++++++++++++++++++++++++++++++ drivers/usb/usbip/usbip_common.h | 12 ++++++++ 2 files changed, 62 insertions(+) diff --git a/drivers/usb/usbip/usbip_common.c b/drivers/usb/usbip/usbip_common.c index 2ab99244bc31..9f677c5a74e8 100644 --- a/drivers/usb/usbip/usbip_common.c +++ b/drivers/usb/usbip/usbip_common.c @@ -748,6 +748,56 @@ int usbip_recv_xbuff(struct usbip_device *ud, struct urb *urb) } EXPORT_SYMBOL_GPL(usbip_recv_xbuff); +int usbip_prepare_threads(struct usbip_thread_info *uti, + struct usbip_device *ud, int sockfd, + int (*tx_fn)(void *data), const char *tx_name, + int (*rx_fn)(void *data), const char *rx_name) +{ + int err; + struct socket *socket; + struct task_struct *tx; + struct task_struct *rx; + + /* Extract socket from fd. */ + socket = sockfd_lookup(sockfd, &err); + if (!socket) + return -EINVAL; + /* Create threads for this socket. */ + rx = kthread_create(rx_fn, ud, rx_name); + if (IS_ERR(rx)) { + err = PTR_ERR(rx); + goto out_socket; + } + tx = kthread_create(tx_fn, ud, tx_name); + if (IS_ERR(tx)) { + err = PTR_ERR(tx); + goto out_rx; + } + uti->tcp_socket = socket; + get_task_struct(rx); + uti->tcp_rx = rx; + get_task_struct(tx); + uti->tcp_tx = tx; + return 0; + out_rx: + kthread_stop(rx); + out_socket: + sockfd_put(socket); + return err; +} +EXPORT_SYMBOL_GPL(usbip_prepare_threads); + +void usbip_unprepare_threads(struct usbip_thread_info *uti) +{ + kthread_stop_put(uti->tcp_tx); + uti->tcp_tx = NULL; + kthread_stop_put(uti->tcp_rx); + uti->tcp_rx = NULL; + sockfd_put(uti->tcp_socket); + uti->tcp_socket = NULL; +} +EXPORT_SYMBOL_GPL(usbip_unprepare_threads); + static int __init usbip_core_init(void) { return usbip_init_eh(); diff --git a/drivers/usb/usbip/usbip_common.h b/drivers/usb/usbip/usbip_common.h index 6e2a80b1633d..6e5394dba2ec 100644 --- a/drivers/usb/usbip/usbip_common.h +++ b/drivers/usb/usbip/usbip_common.h @@ -316,6 +316,18 @@ void usbip_header_correct_endian(struct usbip_header *pdu, int send); struct usbip_iso_packet_descriptor* usbip_alloc_iso_desc_pdu(struct urb *urb, ssize_t *bufflen); +struct usbip_thread_info { + struct socket *tcp_socket; + struct task_struct *tcp_tx; + struct task_struct *tcp_rx; +}; + +int usbip_prepare_threads(struct usbip_thread_info *uti, + struct usbip_device *ud, int sockfd, + int (*tx_fn)(void *data), const char *tx_name, + int (*rx_fn)(void *data), const char *rx_name); +void usbip_unprepare_threads(struct usbip_thread_info *uti); + /* some members of urb must be substituted before. */ int usbip_recv_iso(struct usbip_device *ud, struct urb *urb); void usbip_pad_iso(struct usbip_device *ud, struct urb *urb);