Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756106AbbGFWrE (ORCPT ); Mon, 6 Jul 2015 18:47:04 -0400 Received: from v094114.home.net.pl ([79.96.170.134]:52865 "HELO v094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1754873AbbGFWqz (ORCPT ); Mon, 6 Jul 2015 18:46:55 -0400 From: "Rafael J. Wysocki" To: Felipe Balbi Cc: linux-pm@vger.kernel.org, Tony Lindgren , Linux OMAP Mailing List , Linux ARM Kernel Mailing List , Linux Kernel Mailing List , Tony Lindgren Subject: Re: [PATCH] base: power: wakeirq: don't leak dev->power.wakeirq Date: Tue, 07 Jul 2015 01:13:21 +0200 Message-ID: <2783932.o7RC7vMDHB@vostro.rjw.lan> User-Agent: KMail/4.11.5 (Linux/4.1.0-rc5+; KDE/4.11.5; x86_64; ; ) In-Reply-To: <1436205678-31640-1-git-send-email-balbi@ti.com> References: <1436205678-31640-1-git-send-email-balbi@ti.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4154 Lines: 159 On Monday, July 06, 2015 01:01:18 PM Felipe Balbi wrote: > on a first call to dev_pm_attach_wake_irq(), if it > fails, it will leave dev->power.wakeirq set to a > dangling pointer. Instead, let's clear it to make > sure a subsequent call to dev_pm_attach_wake_irq() > has chance to succeed. > > Cc: Tony Lindgren > Signed-off-by: Felipe Balbi > --- > drivers/base/power/wakeirq.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > > diff --git a/drivers/base/power/wakeirq.c b/drivers/base/power/wakeirq.c > index 7470004ca810..394d250a1ad8 100644 > --- a/drivers/base/power/wakeirq.c > +++ b/drivers/base/power/wakeirq.c > @@ -50,9 +50,16 @@ static int dev_pm_attach_wake_irq(struct device *dev, int irq, > > err = device_wakeup_attach_irq(dev, wirq); > if (err) > - return err; > + goto err_cleanup; > > return 0; > + > +err_cleanup: > + spin_lock_irqsave(&dev->power.lock, flags); > + dev->power.wakeirq = NULL; > + spin_unlock_irqrestore(&dev->power.lock, flags); > + > + return err; > } Too many labels for me and the fact that acquiring of the lock again in the error patch doesn't look good. However, we can do the entire device_wakeup_attach_irq() under the lock (after removing the locking from it), because we're its only caller. So what about the below instead (build-tested only)? Rafael --- drivers/base/power/wakeirq.c | 12 +++++------- drivers/base/power/wakeup.c | 31 ++++++++++--------------------- 2 files changed, 15 insertions(+), 28 deletions(-) Index: linux-pm/drivers/base/power/wakeirq.c =================================================================== --- linux-pm.orig/drivers/base/power/wakeirq.c +++ linux-pm/drivers/base/power/wakeirq.c @@ -45,14 +45,12 @@ static int dev_pm_attach_wake_irq(struct return -EEXIST; } - dev->power.wakeirq = wirq; - spin_unlock_irqrestore(&dev->power.lock, flags); - err = device_wakeup_attach_irq(dev, wirq); - if (err) - return err; + if (!err) + dev->power.wakeirq = wirq; - return 0; + spin_unlock_irqrestore(&dev->power.lock, flags); + return err; } /** @@ -105,10 +103,10 @@ void dev_pm_clear_wake_irq(struct device return; spin_lock_irqsave(&dev->power.lock, flags); + device_wakeup_detach_irq(dev); dev->power.wakeirq = NULL; spin_unlock_irqrestore(&dev->power.lock, flags); - device_wakeup_detach_irq(dev); if (wirq->dedicated_irq) free_irq(wirq->irq, wirq); kfree(wirq); Index: linux-pm/drivers/base/power/wakeup.c =================================================================== --- linux-pm.orig/drivers/base/power/wakeup.c +++ linux-pm/drivers/base/power/wakeup.c @@ -281,32 +281,25 @@ EXPORT_SYMBOL_GPL(device_wakeup_enable); * Attach a device wakeirq to the wakeup source so the device * wake IRQ can be configured automatically for suspend and * resume. + * + * Call under the device's power.lock lock. */ int device_wakeup_attach_irq(struct device *dev, struct wake_irq *wakeirq) { struct wakeup_source *ws; - int ret = 0; - spin_lock_irq(&dev->power.lock); ws = dev->power.wakeup; if (!ws) { dev_err(dev, "forgot to call call device_init_wakeup?\n"); - ret = -EINVAL; - goto unlock; + return -EINVAL; } - if (ws->wakeirq) { - ret = -EEXIST; - goto unlock; - } + if (ws->wakeirq) + return -EEXIST; ws->wakeirq = wakeirq; - -unlock: - spin_unlock_irq(&dev->power.lock); - - return ret; + return 0; } /** @@ -314,20 +307,16 @@ unlock: * @dev: Device to handle * * Removes a device wakeirq from the wakeup source. + * + * Call under the device's power.lock lock. */ void device_wakeup_detach_irq(struct device *dev) { struct wakeup_source *ws; - spin_lock_irq(&dev->power.lock); ws = dev->power.wakeup; - if (!ws) - goto unlock; - - ws->wakeirq = NULL; - -unlock: - spin_unlock_irq(&dev->power.lock); + if (ws) + ws->wakeirq = NULL; } /** -- 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/