Re: [PATCH 1/1] hwmon: (ina2xx) initialize mutex before locking

[Guenter Roeck <linux@roeck-us.net>]

On Mon, Apr 16, 2018 at 10:48:03PM +0500, Ahsan Hussain wrote:
> 
> 
> On 04/16/2018 10:28 PM, Guenter Roeck wrote:
> > On Mon, Apr 16, 2018 at 10:08:19PM +0500, Ahsan Hussain wrote:
> >>
> >> Upstream commit
> >>
> >> 8d008c0c ("hwmon: (ina2xx) Make calibration register value fixed")
> >>
> > This doesn't have to be on separate lines; as written, it just causes
> > confusion.
> > 
> Will do in my next email.
> >> makes ina2xx_set_shunt() call mutex_lock on an un-initialized mutex.
> >> Initialize it prior so we don't get a NULL pointer dereference error
> >>
> >> Signed-off-by: Ahsan Hussain <ahsan_hussain@mentor.com>
> > 
> > Good find, but your patch is corrupted to the point where any attenpt to
> > fix it up on my side failed. Please resend without corruption, and please
> > provide a Fixes: line.
> Appologies. This must be Thunderbird, I've been trying to coax into
> doing otherwise. Will send the corrected patch shortly.

Best is to set up and use git send-email. Anyway, you can see the result
of the corruption at https://patchwork.kernel.org/patch/10343535/;
it appears that patchwork doesn't understand your patch either.

Guenter

> > 
> > Thanks,
> > Guenter
> > 
> >> ---
> >>  drivers/hwmon/ina2xx.c | 4 ++--
> >>  1 file changed, 2 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/drivers/hwmon/ina2xx.c b/drivers/hwmon/ina2xx.c
> >> index a629f7c..1304f01 100644
> >> --- a/drivers/hwmon/ina2xx.c
> >> +++ b/drivers/hwmon/ina2xx.c
> >> @@ -457,6 +457,8 @@ static int ina2xx_probe(struct i2c_client *client,
> >>  			val = INA2XX_RSHUNT_DEFAULT;
> >>  	}
> >>  +	mutex_init(&data->config_lock);
> >> +
> >>  	ina2xx_set_shunt(data, val);
> >>   	ina2xx_regmap_config.max_register = data->config->registers;
> >> @@ -473,8 +475,6 @@ static int ina2xx_probe(struct i2c_client *client,
> >>  		return -ENODEV;
> >>  	}
> >>  -	mutex_init(&data->config_lock);
> >> -
> >>  	data->groups[group++] = &ina2xx_group;
> >>  	if (id->driver_data == ina226)
> >>  		data->groups[group++] = &ina226_group;
> >> -- 
> >> 2.7.4
> >>