linux-kernel - Re: [PATCH] tvp7002: use devm_kzalloc() instead of kzalloc()

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 03 Jan 2013 14:32:50 +0100
From:	Laurent Pinchart <laurent.pinchart@...asonboard.com>
To:	davinci-linux-open-source@...ux.davincidsp.com
Cc:	Mauro Carvalho Chehab <mchehab@...radead.org>,
	Hans Verkuil <hans.verkuil@...co.com>,
	LKML <linux-kernel@...r.kernel.org>,
	LMML <linux-media@...r.kernel.org>
Subject: Re: [PATCH] tvp7002: use devm_kzalloc() instead of kzalloc()

On Thursday 03 January 2013 14:31:20 Laurent Pinchart wrote:
> On Thursday 03 January 2013 18:52:42 Lad, Prabhakar wrote:
> > I2C drivers can use devm_kzalloc() too in their .probe() methods. Doing so
> > simplifies their clean up paths.
> > 
> > Signed-off-by: Lad, Prabhakar <prabhakar.lad@...com>
> > Signed-off-by: Manjunath Hadli <manjunath.hadli@...com>
> > ---
> > 
> >  drivers/media/i2c/tvp7002.c |   10 ++--------
> >  1 files changed, 2 insertions(+), 8 deletions(-)
> > 
> > diff --git a/drivers/media/i2c/tvp7002.c b/drivers/media/i2c/tvp7002.c
> > index fb6a5b5..2d4c86e 100644
> > --- a/drivers/media/i2c/tvp7002.c
> > +++ b/drivers/media/i2c/tvp7002.c
> > @@ -1036,7 +1036,7 @@ static int tvp7002_probe(struct i2c_client *c, const
> > struct i2c_device_id *id) return -ENODEV;
> > 
> >  	}
> > 
> > -	device = kzalloc(sizeof(struct tvp7002), GFP_KERNEL);
> > +	device = devm_kzalloc(&c->dev, sizeof(struct tvp7002), GFP_KERNEL);
> > 
> >  	if (!device)
> >  	
> >  		return -ENOMEM;
> > 
> > @@ -1088,17 +1088,12 @@ static int tvp7002_probe(struct i2c_client *c,
> > const struct i2c_device_id *id) V4L2_CID_GAIN, 0, 255, 1, 0);
> > 
> >  	sd->ctrl_handler = &device->hdl;
> >  	if (device->hdl.error) {
> > 
> > -		int err = device->hdl.error;
> > -
> > 
> >  		v4l2_ctrl_handler_free(&device->hdl);
> > 
> > -		kfree(device);
> > -		return err;
> > +		return device->hdl.error;
> 
> At this point device->hdl as been freed (or rather uninitialized, as the
> structure is not dynamically allocated by the control framework), so device-
> >hdl.error is undefined. That's why you need the local err variable.

And this comment holds true for the other patches in this series.

> >
> >  	}
> >  	v4l2_ctrl_handler_setup(&device->hdl);
> >  
> >  found_error:
> > -	if (error < 0)
> > -		kfree(device);
> 
> You can remove the found_error label and return errors directly instead of
> using goto's.
> 
> >  	return error;
> 
> And this can then be turned into return 0.
> 
> >  }
> > 
> > @@ -1120,7 +1115,6 @@ static int tvp7002_remove(struct i2c_client *c)
> > 
> >  	v4l2_device_unregister_subdev(sd);
> >  	v4l2_ctrl_handler_free(&device->hdl);
> > 
> > -	kfree(device);
> > 
> >  	return 0;
> >  
> >  }

-- 
Regards,

Laurent Pinchart

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/