On 06/19/2014 01:01 PM, Greg KH wrote:
On Thu, Jun 19, 2014 at 09:15:36PM +0200, Daniel Vetter wrote:
On Thu, Jun 19, 2014 at 7:00 PM, Greg KH gregkh@linuxfoundation.org wrote:
BUG_ON(f1->context != f2->context);Nice, you just crashed the kernel, making it impossible to debug or recover :(
agreed, that should probably be 'if (WARN_ON(...)) return NULL;'
(but at least I wouldn't expect to hit that under console_lock so you should at least see the last N lines of the backtrace on the screen ;-))
Lots of devices don't have console screens :)
Aside: This is a pet peeve of mine and recently I've switched to rejecting all patch that have a BUG_ON, period.
Please do, I have been for a few years now as well for the same reasons you cite.
I'm actually concerned about this trend. Downgrading things to WARN_ON can allow a security bug in the kernel to continue to exist, for example, or make the error message disappear.
I am wondering if the right thing here isn't to have a user (command line?) settable policy as to how to proceed on an assert violation, instead of hardcoding it at compile time.
-hpa