Re: [PATCHv2] [media] af0933: Don't go past arrays

[Mauro Carvalho Chehab <mchehab@osg.samsung.com>]

Em Wed, 05 Nov 2014 04:44:22 +0200
Antti Palosaari <crope@iki.fi> escreveu:

> Acked-by: Antti Palosaari <crope@iki.fi>
> Reviewed-by: Antti Palosaari <crope@iki.fi>
> 
> anyhow, I think these branches could never taken in real life.

Yes, probably this never happens with current code.

> But as a 
> killing warnings and potential future changes I am pretty fine!

The main goal is to kill warnings, but it also prevents future
mistakes. It is a way better to have a warning printed than
to go past the buffer and get random errors.

Regards,
Mauro

> 
> regards
> Antti
> 
> On 11/04/2014 10:35 PM, Mauro Carvalho Chehab wrote:
> > Fixes the following sparse warnings:
> > 	drivers/media/dvb-frontends/af9033.c:295 af9033_init() error: buffer overflow 'clock_adc_lut' 11 <= 11
> > 	drivers/media/dvb-frontends/af9033.c:300 af9033_init() error: buffer overflow 'clock_adc_lut' 11 <= 11
> > 	drivers/media/dvb-frontends/af9033.c:584 af9033_set_frontend() error: buffer overflow 'coeff_lut' 3 <= 3
> > 	drivers/media/dvb-frontends/af9033.c:595 af9033_set_frontend() error: buffer overflow 'clock_adc_lut' 11 <= 11
> >
> > Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
> >
> > -
> > v2: Only changed the patch subject, as it fixes occurrences on 3
> >      different arrays.
> >
> > diff --git a/drivers/media/dvb-frontends/af9033.c b/drivers/media/dvb-frontends/af9033.c
> > index c17e34fd0fb4..82ce47bdf5dc 100644
> > --- a/drivers/media/dvb-frontends/af9033.c
> > +++ b/drivers/media/dvb-frontends/af9033.c
> > @@ -291,6 +291,12 @@ static int af9033_init(struct dvb_frontend *fe)
> >   		if (clock_adc_lut[i].clock == dev->cfg.clock)
> >   			break;
> >   	}
> > +	if (i == ARRAY_SIZE(clock_adc_lut)) {
> > +		dev_err(&dev->client->dev,
> > +			"Couldn't find ADC config for clock=%d\n",
> > +			dev->cfg.clock);
> > +		goto err;
> > +	}
> >
> >   	adc_cw = af9033_div(dev, clock_adc_lut[i].adc, 1000000ul, 19ul);
> >   	buf[0] = (adc_cw >>  0) & 0xff;
> > @@ -580,7 +586,15 @@ static int af9033_set_frontend(struct dvb_frontend *fe)
> >   				break;
> >   			}
> >   		}
> > -		ret =  af9033_wr_regs(dev, 0x800001,
> > +		if (i == ARRAY_SIZE(coeff_lut)) {
> > +			dev_err(&dev->client->dev,
> > +				"Couldn't find LUT config for clock=%d\n",
> > +				dev->cfg.clock);
> > +			ret = -EINVAL;
> > +			goto err;
> > +		}
> > +
> > +		ret = af9033_wr_regs(dev, 0x800001,
> >   				coeff_lut[i].val, sizeof(coeff_lut[i].val));
> >   	}
> >
> > @@ -592,6 +606,13 @@ static int af9033_set_frontend(struct dvb_frontend *fe)
> >   			if (clock_adc_lut[i].clock == dev->cfg.clock)
> >   				break;
> >   		}
> > +		if (i == ARRAY_SIZE(clock_adc_lut)) {
> > +			dev_err(&dev->client->dev,
> > +				"Couldn't find ADC clock for clock=%d\n",
> > +				dev->cfg.clock);
> > +			ret = -EINVAL;
> > +			goto err;
> > +		}
> >   		adc_freq = clock_adc_lut[i].adc;
> >
> >   		/* get used IF frequency */
> >
>