From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 7 Mar 2018 07:13:51 -0800 From: Greg Kroah-Hartman To: Florian Schmaus Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH] driver-core: Log the BUG() causing driver Message-ID: <20180307151351.GA1598@kroah.com> References: <20180307094902.20316-1-flo@geekplace.eu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180307094902.20316-1-flo@geekplace.eu> User-Agent: Mutt/1.9.4 (2018-02-28) X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On Wed, Mar 07, 2018 at 10:49:02AM +0100, Florian Schmaus wrote: > I triggerd the BUG_ON(), which was added in > f48f3febb2cbfd0f2ecee7690835ba745c1034a4, when booting a domU Xen > domain. How? > Since there was no contextual information logged, I needed to > attach kgdb to determine the culprit (the wmi-bmof driver in my case). > > Signed-off-by: Florian Schmaus > --- > drivers/base/driver.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/drivers/base/driver.c b/drivers/base/driver.c > index ba912558a510..55f8db41df2b 100644 > --- a/drivers/base/driver.c > +++ b/drivers/base/driver.c > @@ -148,7 +148,11 @@ int driver_register(struct device_driver *drv) > int ret; > struct device_driver *other; > > - BUG_ON(!drv->bus->p); > + if (!drv->bus->p) { > + printk(KERN_ERR "Driver '%s' was unable to register bus_type\n", > + drv->name); > + BUG(); > + } We could just log the error and return with an error, that would be nicer, right? Crashing the system isn't usually a good idea, even at boot time :) thanks, greg k-h