On Tue 27-06-17 12:29:39, Andi Kleen wrote: > On Tue, Jun 27, 2017 at 09:11:28PM +0200, Jason A. Donenfeld wrote: [...] > > The bigger question, though, is the value of these checks in the first > > place. Has anybody written a coccinelle check to look into this > > statically? Has it historically been a useful thing for driver > > developers to have? Is it good defense in depth or is it overkill? At > > the very least, the original authors of kref thought a WARN_ON was > > warranted, which means probably a BUG_ON is a sensible fix, until > > somebody does the work of investigating these more careful questions. > > Right that's the question that should have been answered before > this patch. > > I don't think it was ever intended to be a defense, just as a hint > for driver developers. > > My suspicion is that they're mostly useless.
Completely agreed here! -- Michal Hocko SUSE Labs
