I've just tried to upgrade from 3.17.7-hardened-r1.
I've opened a bug for it here:
https://bugs.gentoo.org/show_bug.cgi?id=535976
I'm not convinced it's a grsec/PaX problem. But I'm curious if anybody else had a bad experience with a patched 3.18.1 kernel recently.
I've slipped into 2015 pretty smoothly running 3.17.7-hardened-r1 for the past two weeks now.
Thx & happy new year: Dw.