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Date: Sun, 19 Feb 2012 12:48:20 +1100
From: NeilBrown <neilb@suse.de>
To: Dan Carpenter <dan.carpenter@oracle.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: w1: Fix w1_bq27000
Message-ID: <20120219124820.4a8989f0@notabene.brown>
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On Sat, 18 Feb 2012 23:51:25 +0300 Dan Carpenter <dan.carpenter@oracle.com>
wrote:

> Hello NeilBrown,
>=20
> This is a semi-automatic email about new static checker warnings.
>=20
> The patch 9f3519d2ed26: "w1: Fix w1_bq27000" from Feb 15, 2012, leads=20
> to the following Smatch complaint:
>=20
> drivers/w1/slaves/w1_bq27000.c:48 w1_bq27000_read()
> 	 warn: variable dereferenced before check 'dev' (see line 46)
>=20
> drivers/w1/slaves/w1_bq27000.c
>     45		u8 val;
>     46		struct w1_slave *sl =3D container_of(dev->parent, struct w1_slave=
, dev);
>                                                    ^^^^^^^^^^^
> New dereference.
>=20
>     47=09
>     48		if (!dev)
>                      ^^^
> Old check.
>=20
>     49			return 0;
>     50=09
>=20
> regards,
> dan carpenter

Thanks..
I suspect we should just remove the
   if (!dev)
       return

I should probably get rid of w1_bq27000_write as it is totally unused, and I
need to hold a lock in w1_bq27000_read or I can get really bad things
happening if two threads try to rad the status at the same time.

Ho hum.

Thanks,
NeilBrown

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