Hi Malcolm,
Quoting Malcolm Priestley <tvboxspy@xxxxxxxxx>:
Hi
On 18/05/17 20:09, Gustavo A. R. Silva wrote:
Hello everybody,
While looking into Coverity ID 1226934 I ran into the following
piece of code at drivers/media/usb/dvb-usb-v2/lmedm04.c:205
205static int lme2510_stream_restart(struct dvb_usb_device *d)
206{
207 struct lme2510_state *st = d->priv;
208 u8 all_pids[] = LME_ALL_PIDS;
209 u8 stream_on[] = LME_ST_ON_W;
210 int ret;
211 u8 rbuff[1];
212 if (st->pid_off)
213 ret = lme2510_usb_talk(d, all_pids, sizeof(all_pids),
214 rbuff, sizeof(rbuff));
215 /*Restart Stream Command*/
216 ret = lme2510_usb_talk(d, stream_on, sizeof(stream_on),
217 rbuff, sizeof(rbuff));
218 return ret;
219}
It is a mistake it should have been ORed ad in |= as
lme2510_usb_talk only returns three states.
I see now. The idea is to code something similar to the following
piece of code in the same file:
242
243 ret |= lme2510_usb_talk(d, pid_buff ,
244 sizeof(pid_buff) , rbuf, sizeof(rbuf));
245
246 if (st->stream_on)
247 ret |= lme2510_stream_restart(d);
248
249 return ret;
right?
So in this case, the following patch would properly fix the bug:
index 924adfd..3ab1754 100644
--- a/drivers/media/usb/dvb-usb-v2/lmedm04.c
+++ b/drivers/media/usb/dvb-usb-v2/lmedm04.c
@@ -207,13 +207,14 @@ static int lme2510_stream_restart(struct
dvb_usb_device *d)
struct lme2510_state *st = d->priv;
u8 all_pids[] = LME_ALL_PIDS;
u8 stream_on[] = LME_ST_ON_W;
- int ret;
+ int ret = 0;
u8 rbuff[1];
+
if (st->pid_off)
ret = lme2510_usb_talk(d, all_pids, sizeof(all_pids),
rbuff, sizeof(rbuff));
/*Restart Stream Command*/
- ret = lme2510_usb_talk(d, stream_on, sizeof(stream_on),
+ ret |= lme2510_usb_talk(d, stream_on, sizeof(stream_on),
rbuff, sizeof(rbuff));
return ret;
}
What do you think?
So if an error is in the running it will be returned to user.
The first of your patches is better and more or less the same, the
second would break driver, restart is not an else condition.
Thank you for the clarification.
--
Gustavo A. R. Silva
