https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69624
--- Comment #9 from Jiri Slaby <jirislaby at gmail dot com> --- (In reply to Dmitry Vyukov from comment #8) > First of all, are you sure that r12 is not 0 before the call? Yes. > Deference of 0xdffffc0000000000 is how KASAN reacts on NULL deref, it does > shadow check before the memory accesses. If original address is NULL, the > shadow check will go to 0xdffffc0000000000. I see such GPFs quite > frequently, so that's what I would assume first. I know, I thought so first too. But later, I debugged that to a gcc bug :). > If you just switched to gcc6, then it can be some latent bug (undefined > behavior), which started to fire with a new compiler. W/ CONFIG_KCOV=n (i.e. no -fsanitize-coverage), it works, apparently.
