Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759725Ab2FGGBc (ORCPT ); Thu, 7 Jun 2012 02:01:32 -0400 Received: from mail-qa0-f74.google.com ([209.85.216.74]:60536 "EHLO mail-qa0-f74.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750703Ab2FGGBb (ORCPT ); Thu, 7 Jun 2012 02:01:31 -0400 From: Ben Chan To: Greg Kroah-Hartman Cc: devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org, Ben Chan , Sage Ahn Subject: [PATCH] staging: gdm72xx: Fix spinlock recursion on gdm_usb_send_complete Date: Wed, 6 Jun 2012 23:01:26 -0700 Message-Id: <1339048886-11956-1-git-send-email-benchan@chromium.org> X-Mailer: git-send-email 1.7.7.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2473 Lines: 88 This patch fixes a spinlock recursion bug on several call sites of gdm_usb_send_complete by not calling spin_lock_irqsave on urb->context->tx_cxt->lock when the lock has already been acquired. Signed-off-by: Ben Chan Cc: Sage Ahn --- drivers/staging/gdm72xx/gdm_usb.c | 24 ++++++++++++++++++------ 1 files changed, 18 insertions(+), 6 deletions(-) diff --git a/drivers/staging/gdm72xx/gdm_usb.c b/drivers/staging/gdm72xx/gdm_usb.c index 1e9dc0d..a362e0c 100644 --- a/drivers/staging/gdm72xx/gdm_usb.c +++ b/drivers/staging/gdm72xx/gdm_usb.c @@ -270,7 +270,7 @@ static void release_usb(struct usbwm_dev *udev) } } -static void gdm_usb_send_complete(struct urb *urb) +static void gdm_usb_send_complete_impl(struct urb *urb, bool need_lock) { struct usb_tx *t = urb->context; struct tx_cxt *tx = t->tx_cxt; @@ -282,7 +282,8 @@ static void gdm_usb_send_complete(struct urb *urb) if (urb->status == -ECONNRESET) return; - spin_lock_irqsave(&tx->lock, flags); + if (need_lock) + spin_lock_irqsave(&tx->lock, flags); if (t->callback) t->callback(t->cb_data); @@ -296,7 +297,18 @@ static void gdm_usb_send_complete(struct urb *urb) else free_tx_struct(t); - spin_unlock_irqrestore(&tx->lock, flags); + if (need_lock) + spin_unlock_irqrestore(&tx->lock, flags); +} + +static void gdm_usb_send_complete(struct urb *urb) +{ + gdm_usb_send_complete_impl(urb, true); +} + +static void gdm_usb_send_complete_no_lock(struct urb *urb) +{ + gdm_usb_send_complete_impl(urb, false); } static int gdm_usb_send(void *priv_dev, void *data, int len, @@ -411,7 +423,7 @@ out: send_fail: t->callback = NULL; - gdm_usb_send_complete(t->urb); + gdm_usb_send_complete_no_lock(t->urb); spin_unlock_irqrestore(&tx->lock, flags); return ret; } @@ -540,7 +552,7 @@ static void do_pm_control(struct work_struct *work) if (ret) { t->callback = NULL; - gdm_usb_send_complete(t->urb); + gdm_usb_send_complete_no_lock(t->urb); } } } @@ -742,7 +754,7 @@ static int k_mode_thread(void *arg) if (ret) { t->callback = NULL; - gdm_usb_send_complete(t->urb); + gdm_usb_send_complete_no_lock(t->urb); } } -- 1.7.7.3 -- 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/