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

[Ahsan Hussain]

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@xxxxxxxxxx>
> 
> 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.
> 
> 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
>>