Subject: Re: [PATCH V3 3/7] Drivers: hv: vmbus: add APIs to send/recv hvsock packet and get the r/w-ability

From: Dan Carpenter <[email-masked]>
Date: Thu, 23 Jul 2015 13:24:50 +0300

On Thu, Jul 23, 2015 at 01:10:57PM +0300, Dan Carpenter wrote:
> In this specific case, writing it as "if (ret != 0)" caused the bug.  If
> we had written it as "if (ret) return ret;" then there are no zeroes so
> wouldn't have been any temptation to return the zero instead of the ret.

I did a search to see if returning the zero instead of the ret was a
common mistake and it seems like it might be.  I did:

grep 'if (ret != 0)' drivers/   -r -A1 -n | grep "return 0;" | perl -ne 's/.c-(\d+)-/.c:$1/; print'

drivers/gpu/drm/nouveau/nouveau_display.c:111                   return 0;
drivers/regulator/wm8400-regulator.c:47         return 0;
drivers/platform/x86/dell-laptop.c:859          return 0;
drivers/media/dvb-frontends/dibx000_common.c:213                                return 0;
drivers/media/dvb-frontends/dibx000_common.c:217                                return 0;
drivers/media/dvb-frontends/dibx000_common.c:235                                return 0;
drivers/media/dvb-frontends/dibx000_common.c:239                                return 0;
drivers/hv/channel.c:898                return 0;
drivers/hv/channel.c:944                return 0;

A bunch of those look suspicious but I don't know the subsystems well
enough to be sure.  Can you check the last two?

regards,
dan carpenter