Re: [PATCH 1/3] iio: dac: ad5592r: fix unbalanced mutex unlocks in ad5592r_read_raw()

From: Jonathan Cameron <jic23@kernel.org>
To: "Ardelean, Alexandru" <alexandru.Ardelean@analog.com>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-iio@vger.kernel.org" <linux-iio@vger.kernel.org>,
	"charles.stanhope@gmail.com" <charles.stanhope@gmail.com>
Subject: Re: [PATCH 1/3] iio: dac: ad5592r: fix unbalanced mutex unlocks in ad5592r_read_raw()
Date: Sun, 12 Jul 2020 12:16:59 +0100	[thread overview]
Message-ID: <20200712121659.1792a7dd@archlinux> (raw)
In-Reply-To: <872263d31269c590c34b46ccb6517ec26a330c18.camel@analog.com>

On Mon, 6 Jul 2020 16:36:09 +0000
"Ardelean, Alexandru" <alexandru.Ardelean@analog.com> wrote:

> On Mon, 2020-07-06 at 14:02 +0300, Alexandru Ardelean wrote:
> > [External]
> > 
> > There are 2 exit paths where the lock isn't held, but try to unlock the
> > mutex when exiting. In these places we should just return from the
> > function.
> > 
> > A neater approach would be to cleanup the ad5592r_read_raw(), but that
> > would make this patch more difficult to backport to stable versions.
> >   
> 
> I was a bit too hasty with this.
> Apologies.
> I'd like to add a tag here.
> 
> Reported-by: Charles Stanhope <charles.stanhope@gmail.com>
Applied to the fixes-togreg branch of iio.git.

I'll have to wait for this to trickle through to the togreg branch though
before I can do anything with the next two patches.  As ever, if I've
clearly lost them give me a poke!

Jonathan

> 
> > Fixes 56ca9db862bf3: ("iio: dac: Add support for the AD5592R/AD5593R
> > ADCs/DACs")
> > Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
> > ---
> >  drivers/iio/dac/ad5592r-base.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/iio/dac/ad5592r-base.c b/drivers/iio/dac/ad5592r-
> > base.c
> > index 5c4e5ff70380..cc4875660a69 100644
> > --- a/drivers/iio/dac/ad5592r-base.c
> > +++ b/drivers/iio/dac/ad5592r-base.c
> > @@ -413,7 +413,7 @@ static int ad5592r_read_raw(struct iio_dev *iio_dev,
> >  			s64 tmp = *val * (3767897513LL / 25LL);
> >  			*val = div_s64_rem(tmp, 1000000000LL, val2);
> >  
> > -			ret = IIO_VAL_INT_PLUS_MICRO;
> > +			return IIO_VAL_INT_PLUS_MICRO;
> >  		} else {
> >  			int mult;
> >  
> > @@ -444,7 +444,7 @@ static int ad5592r_read_raw(struct iio_dev *iio_dev,
> >  		ret =  IIO_VAL_INT;
> >  		break;
> >  	default:
> > -		ret = -EINVAL;
> > +		return -EINVAL;
> >  	}
> >  
> >  unlock:  