1*2a44cccdSAlexander LeidingerBuild the basesystem with code to zero caller-used register contents 2*2a44cccdSAlexander Leidingeron function return. 3*2a44cccdSAlexander LeidingerThis prevents leaking temporary values for side channel attacks. 4*2a44cccdSAlexander LeidingerAdditionally this reduces the number of usable ROP gadgets for attackers. 5