From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexander Stein Date: Wed, 05 Sep 2018 10:06:55 +0000 Subject: Re: [PATCH] staging: most: video: fix registration of an empty comp core_component Message-Id: <1588498.TolbaFeo5X@ws-140106> List-Id: References: <20180905094605.14827-1-colin.king@canonical.com> In-Reply-To: <20180905094605.14827-1-colin.king@canonical.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Colin King Cc: Greg Kroah-Hartman , Christian Gromm , Abdun Nihaal , devel@driverdev.osuosl.org, kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org On Wednesday, September 5, 2018, 11:46:05 AM CEST Colin King wrote: > From: Colin Ian King > > Currently we have structrues comp (which is empty) and comp_info being > used to register and deregister the component. This mismatch in naming > occurred from a previous commit that renamed aim_info to comp. Fix this > to use consistent component naming in line with most/net, most/sound etc. > > This fixes the message two issues, one with a null empty name when > loading the module: > > [ 1485.269515] most_core: registered new core component (null) > > and an Oops when removing the module: > > [ 1485.277971] BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 > [ 1485.278648] PGD 0 P4D 0 > [ 1485.279253] Oops: 0002 [#2] SMP PTI > [ 1485.279847] CPU: 1 PID: 32629 Comm: modprobe Tainted: P D WC OE 4.18.0-8-generic #9 > [ 1485.280442] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015 > [ 1485.281040] RIP: 0010:most_deregister_component+0x3c/0x70 [most_core] > .. etc > > Fixes: 1b10a0316e2d ("staging: most: video: remove aim designators") > Signed-off-by: Colin Ian King > --- > drivers/staging/most/video/video.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/staging/most/video/video.c b/drivers/staging/most/video/video.c > index cf342eb58e10..ad7e28ab9a4f 100644 > --- a/drivers/staging/most/video/video.c > +++ b/drivers/staging/most/video/video.c > @@ -530,7 +530,7 @@ static int comp_disconnect_channel(struct most_interface *iface, > return 0; > } > > -static struct core_component comp_info = { > +static struct core_component comp = { > .name = "video", > .probe_channel = comp_probe_channel, > .disconnect_channel = comp_disconnect_channel, Doesn't it make more sense to move that variable defintion where currently the forward declaration is? This way you can't have 2 variables accidentally. You will need forward declarations for those two functions, but a mismatch here results in a linker error rather than a runtime NULL pointer access Best regards, Alexander