On Fri, May 29, 2020 at 04:29:17PM -0700, David Miller wrote: > From: Peter Zijlstra <peterz@xxxxxxxxxxxxx> > Date: Fri, 29 May 2020 23:35:51 +0200 > > > ../arch/sparc/include/asm/percpu_64.h:7:24: warning: call-clobbered register used for global register variable > > register unsigned long __local_per_cpu_offset asm("g5"); > > The "-ffixed-g5" option on the command line tells gcc that we are > using 'g5' as a fixed register, so some part of your build isn't using > the: > > KBUILD_CFLAGS += -ffixed-g4 -ffixed-g5 -fcall-used-g7 -Wno-sign-compare > > from arch/sparc/Makefile for some reason. Thanks, that was the clue I needed. I think I see, what happens is that these headers end up in the VDSO build, and that doesn't have these CFLAGS, because userspace. Let me see what to do about that.