From patchwork Mon Jun 30 11:52:47 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Jiri Slaby X-Patchwork-Id: 32706 Return-Path: X-Original-To: linaro@patches.linaro.org Delivered-To: linaro@patches.linaro.org Received: from mail-oa0-f70.google.com (mail-oa0-f70.google.com [209.85.219.70]) by ip-10-151-82-157.ec2.internal (Postfix) with ESMTPS id E6D51203F4 for ; Mon, 30 Jun 2014 12:44:15 +0000 (UTC) Received: by mail-oa0-f70.google.com with SMTP id m1sf52625227oag.9 for ; Mon, 30 Jun 2014 05:44:15 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:delivered-to:from:to:cc:subject:date:message-id :in-reply-to:references:in-reply-to:references:mime-version:sender :precedence:list-id:x-original-sender :x-original-authentication-results:mailing-list:list-post:list-help :list-archive:list-unsubscribe:content-type :content-transfer-encoding; bh=bUThNcXvZg2Yh8kwncEd7jAx/CcvgHHRS2pwqw2/FUs=; b=STskKnHKU5L/QlWqlm+kZ3HoY5gs8fZMkl+HVJ5ma0iNUd2bm0NgfspRem6vpgKQmD Uahsv8W/XdEPApldT1gQMXPDEceiJmjeZOg31RZ+cFmyC9kTWpynmWV5r0X4HQtPHG5n 0niBGLkzSTzfAoToq921g0uVo1J6aw1BbNdduGK1ECRgZmudwVGe5OKhEvH0/s8IGFVR c0ibiBnylJcUxEL1soVryer2MGn1JknsIWEAhLAX5g72qzp4Jp5wIwnW9lW7eGg8ELmB wakDixDnFIzAbf5rv0dbxXDHvgxkl7mo88XnhYngKCBnpoSKKoVH5nRxGi89XvB76khU AjSQ== X-Gm-Message-State: ALoCoQng+FZlCR2meDT9ID5AlQ1n/ZHOsoRlk5vLsq81D/q8O+P1Q6HgyEy39OLM05Ck+yku6MT7 X-Received: by 10.182.45.161 with SMTP id o1mr15343311obm.2.1404132255456; Mon, 30 Jun 2014 05:44:15 -0700 (PDT) X-BeenThere: patchwork-forward@linaro.org Received: by 10.140.51.3 with SMTP id t3ls1310746qga.82.gmail; Mon, 30 Jun 2014 05:44:15 -0700 (PDT) X-Received: by 10.52.27.133 with SMTP id t5mr32317068vdg.9.1404132255385; Mon, 30 Jun 2014 05:44:15 -0700 (PDT) Received: from mail-ve0-f172.google.com (mail-ve0-f172.google.com [209.85.128.172]) by mx.google.com with ESMTPS id k14si8220768vdg.49.2014.06.30.05.44.15 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Mon, 30 Jun 2014 05:44:15 -0700 (PDT) Received-SPF: pass (google.com: domain of patch+caf_=patchwork-forward=linaro.org@linaro.org designates 209.85.128.172 as permitted sender) client-ip=209.85.128.172; Received: by mail-ve0-f172.google.com with SMTP id jz11so8050296veb.31 for ; Mon, 30 Jun 2014 05:44:15 -0700 (PDT) X-Received: by 10.52.88.44 with SMTP id bd12mr33743vdb.86.1404132255310; Mon, 30 Jun 2014 05:44:15 -0700 (PDT) X-Forwarded-To: patchwork-forward@linaro.org X-Forwarded-For: patch@linaro.org patchwork-forward@linaro.org Delivered-To: patch@linaro.org Received: by 10.221.37.5 with SMTP id tc5csp135306vcb; Mon, 30 Jun 2014 05:44:14 -0700 (PDT) X-Received: by 10.66.169.136 with SMTP id ae8mr51817492pac.14.1404132254589; Mon, 30 Jun 2014 05:44:14 -0700 (PDT) Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id sx5si23030745pab.126.2014.06.30.05.44.13; Mon, 30 Jun 2014 05:44:14 -0700 (PDT) Received-SPF: none (google.com: linux-kernel-owner@vger.kernel.org does not designate permitted sender hosts) client-ip=209.132.180.67; Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756193AbaF3MoJ (ORCPT + 27 others); Mon, 30 Jun 2014 08:44:09 -0400 Received: from ip4-83-240-18-248.cust.nbox.cz ([83.240.18.248]:53045 "EHLO ip4-83-240-18-248.cust.nbox.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754910AbaF3MbH (ORCPT ); Mon, 30 Jun 2014 08:31:07 -0400 Received: from ku by ip4-83-240-18-248.cust.nbox.cz with local (Exim 4.80.1) (envelope-from ) id 1X1a9I-0000sZ-7I; Mon, 30 Jun 2014 13:53:28 +0200 From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Felipe Balbi , Jiri Slaby Subject: [PATCH 3.12 146/181] bluetooth: hci_ldisc: fix deadlock condition Date: Mon, 30 Jun 2014 13:52:47 +0200 Message-Id: X-Mailer: git-send-email 2.0.0 In-Reply-To: <61844d8e25eb8899b0836afa9796fa239db80f1f.1404128997.git.jslaby@suse.cz> References: <61844d8e25eb8899b0836afa9796fa239db80f1f.1404128997.git.jslaby@suse.cz> In-Reply-To: References: MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org Precedence: list List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-Removed-Original-Auth: Dkim didn't pass. X-Original-Sender: linux-kernel-owner@vger.kernel.org X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of patch+caf_=patchwork-forward=linaro.org@linaro.org designates 209.85.128.172 as permitted sender) smtp.mail=patch+caf_=patchwork-forward=linaro.org@linaro.org Mailing-list: list patchwork-forward@linaro.org; contact patchwork-forward+owners@linaro.org X-Google-Group-Id: 836684582541 List-Post: , List-Help: , List-Archive: List-Unsubscribe: , From: Felipe Balbi 3.12-stable review patch. If anyone has any objections, please let me know. =============== commit da64c27d3c93ee9f89956b9de86c4127eb244494 upstream. LDISCs shouldn't call tty->ops->write() from within ->write_wakeup(). ->write_wakeup() is called with port lock taken and IRQs disabled, tty->ops->write() will try to acquire the same port lock and we will deadlock. Acked-by: Marcel Holtmann Reviewed-by: Peter Hurley Reported-by: Huang Shijie Signed-off-by: Felipe Balbi Tested-by: Andreas Bießmann Signed-off-by: Jiri Slaby --- drivers/bluetooth/hci_ldisc.c | 24 +++++++++++++++++++----- drivers/bluetooth/hci_uart.h | 1 + 2 files changed, 20 insertions(+), 5 deletions(-) diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c index bc68a440d432..c4d2f0e48685 100644 --- a/drivers/bluetooth/hci_ldisc.c +++ b/drivers/bluetooth/hci_ldisc.c @@ -118,10 +118,6 @@ static inline struct sk_buff *hci_uart_dequeue(struct hci_uart *hu) int hci_uart_tx_wakeup(struct hci_uart *hu) { - struct tty_struct *tty = hu->tty; - struct hci_dev *hdev = hu->hdev; - struct sk_buff *skb; - if (test_and_set_bit(HCI_UART_SENDING, &hu->tx_state)) { set_bit(HCI_UART_TX_WAKEUP, &hu->tx_state); return 0; @@ -129,6 +125,22 @@ int hci_uart_tx_wakeup(struct hci_uart *hu) BT_DBG(""); + schedule_work(&hu->write_work); + + return 0; +} + +static void hci_uart_write_work(struct work_struct *work) +{ + struct hci_uart *hu = container_of(work, struct hci_uart, write_work); + struct tty_struct *tty = hu->tty; + struct hci_dev *hdev = hu->hdev; + struct sk_buff *skb; + + /* REVISIT: should we cope with bad skbs or ->write() returning + * and error value ? + */ + restart: clear_bit(HCI_UART_TX_WAKEUP, &hu->tx_state); @@ -153,7 +165,6 @@ restart: goto restart; clear_bit(HCI_UART_SENDING, &hu->tx_state); - return 0; } static void hci_uart_init_work(struct work_struct *work) @@ -289,6 +300,7 @@ static int hci_uart_tty_open(struct tty_struct *tty) tty->receive_room = 65536; INIT_WORK(&hu->init_ready, hci_uart_init_work); + INIT_WORK(&hu->write_work, hci_uart_write_work); spin_lock_init(&hu->rx_lock); @@ -326,6 +338,8 @@ static void hci_uart_tty_close(struct tty_struct *tty) if (hdev) hci_uart_close(hdev); + cancel_work_sync(&hu->write_work); + if (test_and_clear_bit(HCI_UART_PROTO_SET, &hu->flags)) { if (hdev) { if (test_bit(HCI_UART_REGISTERED, &hu->flags)) diff --git a/drivers/bluetooth/hci_uart.h b/drivers/bluetooth/hci_uart.h index fffa61ff5cb1..12df101ca942 100644 --- a/drivers/bluetooth/hci_uart.h +++ b/drivers/bluetooth/hci_uart.h @@ -68,6 +68,7 @@ struct hci_uart { unsigned long hdev_flags; struct work_struct init_ready; + struct work_struct write_work; struct hci_uart_proto *proto; void *priv;