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From: Tony Lindgren <tony@atomide.com>
To: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Felipe Balbi <balbi@ti.com>,
	linux-pm@vger.kernel.org,
	Linux OMAP Mailing List <linux-omap@vger.kernel.org>,
	Linux ARM Kernel Mailing List
	<linux-arm-kernel@lists.infradead.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] base: power: wakeirq: don't leak dev->power.wakeirq
Date: Tue, 7 Jul 2015 00:40:53 -0700	[thread overview]
Message-ID: <20150707074053.GO10705@atomide.com> (raw)
In-Reply-To: <2783932.o7RC7vMDHB@vostro.rjw.lan>

* Rafael J. Wysocki <rjw@rjwysocki.net> [150706 15:49]:
> 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 <tmlind@atomide.com>
> > Signed-off-by: Felipe Balbi <balbi@ti.com>
> > ---
> >  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)?

Nice, still works for me and simplifies things:

Tested-by: Tony Lindgren <tony@atomide.com>

WARNING: multiple messages have this Message-ID (diff)
From: tony@atomide.com (Tony Lindgren)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] base: power: wakeirq: don't leak dev->power.wakeirq
Date: Tue, 7 Jul 2015 00:40:53 -0700	[thread overview]
Message-ID: <20150707074053.GO10705@atomide.com> (raw)
In-Reply-To: <2783932.o7RC7vMDHB@vostro.rjw.lan>

* Rafael J. Wysocki <rjw@rjwysocki.net> [150706 15:49]:
> 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 <tmlind@atomide.com>
> > Signed-off-by: Felipe Balbi <balbi@ti.com>
> > ---
> >  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)?

Nice, still works for me and simplifies things:

Tested-by: Tony Lindgren <tony@atomide.com>

  reply	other threads:[~2015-07-07  7:40 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-07-06 18:01 [PATCH] base: power: wakeirq: don't leak dev->power.wakeirq Felipe Balbi
2015-07-06 18:01 ` Felipe Balbi
2015-07-06 18:01 ` Felipe Balbi
     [not found] ` <CAOf5uwnj=0m99E96k-+AYu68yE_UnX1WVU-=6y7OvJnfXKh8+g@mail.gmail.com>
2015-07-06 18:09   ` Felipe Balbi
2015-07-06 18:09     ` Felipe Balbi
2015-07-06 18:09     ` Felipe Balbi
2015-07-07  4:17     ` Michael Trimarchi
2015-07-07  4:17       ` Michael Trimarchi
2015-07-06 23:13 ` Rafael J. Wysocki
2015-07-06 23:13   ` Rafael J. Wysocki
2015-07-07  7:40   ` Tony Lindgren [this message]
2015-07-07  7:40     ` Tony Lindgren
2015-07-07  8:11     ` Felipe Balbi
2015-07-07  8:11       ` Felipe Balbi
2015-07-07  8:11       ` Felipe Balbi
2015-07-07 11:11       ` Rafael J. Wysocki
2015-07-07 11:11         ` Rafael J. Wysocki

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