On Thu, Jan 25, 2018 at 04:21:51PM +0100, Jiri Slaby wrote: > > The same reason it was applied upstream, it fixes a reported > > issue. > > > > Does that mean that all UBSAN overflow error reports are not valid > > because of how we build the kernel? > > IMO yes, because with the option, signed overflow is not undefined. > > In the long term, it would be nice to get rid of *all* signed integer > overflows and kill the compiler option from Makefile. Therefore the > fixes are indeed very valid in upstream. I actually think the option is unconditionally good. Undefined behaviour in a language is bad. Sadly C has lots of it, but any reduction we can have we must take.