Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934643AbZLKXb3 (ORCPT ); Fri, 11 Dec 2009 18:31:29 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S934369AbZLKX3i (ORCPT ); Fri, 11 Dec 2009 18:29:38 -0500 Received: from kroah.org ([198.145.64.141]:50466 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934445AbZLKX33 (ORCPT ); Fri, 11 Dec 2009 18:29:29 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Alan Cox , Greg Kroah-Hartman Subject: [PATCH 46/58] tty: isicom: fix deadlock on shutdown Date: Fri, 11 Dec 2009 15:28:30 -0800 Message-Id: <1260574122-10676-46-git-send-email-gregkh@suse.de> X-Mailer: git-send-email 1.6.5.3 In-Reply-To: <20091211232805.GA10652@kroah.com> References: <20091211232805.GA10652@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2007 Lines: 63 From: Alan Cox Alexander Strakh reported KERNEL_VERSION: 2.6.31 DESCRIBE: Driver drivers/char/isicom.c might sleep in atomic context, because it calls tty_port_xmit_buf under spin_lock. ./drivers/char/isicom.c: 1307 static void isicom_hangup(struct tty_struct *tty) 1308 { ... 1315 spin_lock_irqsave(&port->card->card_lock, flags); 1316 isicom_shutdown_port(port); ... Path to might_sleep macro from isicom_hangup: 1. isicom_hangup calls spin_lock_irqsave (drivers/char/isicom.c:1315) and then calls isicom_shutdown_port. 2. isiscom_shutdown_port calls tty_port_free_xmit_buf at drivers/char/isicom.c:906 3. tty_port_free_xmit_buf calls mutex_lock at drivers/char/tty_port:48 Found by Linux Driver Verification Project. Reported-by: Alexander Strakh Signed-off-by: Alan Cox Signed-off-by: Greg Kroah-Hartman --- drivers/char/isicom.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/drivers/char/isicom.c b/drivers/char/isicom.c index 1e91c30..300d5bd 100644 --- a/drivers/char/isicom.c +++ b/drivers/char/isicom.c @@ -887,7 +887,6 @@ static void isicom_shutdown_port(struct isi_port *port) { struct isi_board *card = port->card; - tty_port_free_xmit_buf(&port->port); if (--card->count < 0) { pr_dbg("isicom_shutdown_port: bad board(0x%lx) count %d.\n", card->base, card->count); @@ -927,6 +926,7 @@ static void isicom_shutdown(struct tty_port *port) outw(card->port_status, card->base + 0x02); isicom_shutdown_port(ip); spin_unlock_irqrestore(&card->card_lock, flags); + tty_port_free_xmit_buf(port); } static void isicom_close(struct tty_struct *tty, struct file *filp) -- 1.6.5.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/