$ make
[...]
  CHK     include/linux/version.h
  CHK     include/linux/utsrelease.h
  CALL    scripts/checksyscalls.sh
  CHK     include/linux/compile.h
  VDSOSYM arch/x86/vdso/vdso32-int80-syms.lds
  VDSOSYM arch/x86/vdso/vdso32-sysenter-syms.lds
  VDSOSYM arch/x86/vdso/vdso32-syms.lds
  LD      arch/x86/vdso/built-in.o
  LD      vmlinux.o
  MODPOST vmlinux.o
WARNING: modpost: Found 10 section mismatch(es).
To see full details build your kernel with:
'make CONFIG_DEBUG_SECTION_MISMATCH=y'
  GEN     .version
  CHK     include/linux/compile.h
  UPD     include/linux/compile.h
  CC      init/version.o
  LD      init/built-in.o
  LD      .tmp_vmlinux1
kernel/built-in.o: In function `timespec_add_ns':
/data/Scratch/scm/linux-2.6-git/include/linux/time.h:178: undefined reference to `__umoddi3'
/data/Scratch/scm/linux-2.6-git/include/linux/time.h:178: undefined reference to `__udivdi3'
/data/Scratch/scm/linux-2.6-git/include/linux/time.h:178: undefined reference to `__umoddi3'
/data/Scratch/scm/linux-2.6-git/include/linux/time.h:178: undefined reference to `__udivdi3'
kernel/built-in.o: In function `timespec_add_ns':
/data/Scratch/scm/linux-2.6-git/kernel/time/timekeeping.c:277: undefined reference to `__udivdi3'
kernel/built-in.o: In function `timespec_add_ns':
/data/Scratch/scm/linux-2.6-git/include/linux/time.h:178: undefined reference to `__umoddi3'
/data/Scratch/scm/linux-2.6-git/include/linux/time.h:178: undefined reference to `__udivdi3'
/data/Scratch/scm/linux-2.6-git/include/linux/time.h:178: undefined reference to `__umoddi3'
/data/Scratch/scm/linux-2.6-git/include/linux/time.h:178: undefined reference to `__udivdi3'
/data/Scratch/scm/linux-2.6-git/include/linux/time.h:178: undefined reference to `__umoddi3'
/data/Scratch/scm/linux-2.6-git/include/linux/time.h:178: undefined reference to `__udivdi3'
kernel/built-in.o: In function `timespec_add_ns':
/data/Scratch/scm/linux-2.6-git/kernel/time/timekeeping.c:131: undefined reference to `__udivdi3'
/data/Scratch/scm/linux-2.6-git/kernel/time/timekeeping.c:239: undefined reference to `__udivdi3'
make: *** [.tmp_vmlinux1] Error 1