2.5.40: undefined reference to `errno'

[Duncan Sands <baldrick@wanadoo.fr>]

        ld -m elf_i386 -e stext -T arch/i386/vmlinux.lds.s arch/i386/kernel/head.o arch/i386/kernel/init_task.o  init/built-in.o --start-group  arch/i386/kernel/built-in.o  arch/i386/mm/built-in.o  arch/i386/mach-generic/built-in.o kernel/built-in.o mm/built-in.o fs/built-in.o ipc/built-in.o security/built-in.o  lib/lib.a  arch/i386/lib/lib.a  drivers/built-in.o  sound/built-in.o  arch/i386/pci/built-in.o  net/built-in.o --end-group  -o .tmp_vmlinux
init/built-in.o: In function `init':
init/built-in.o(.text+0xf1): undefined reference to `errno'
init/built-in.o(.text+0x124): undefined reference to `errno'
init/built-in.o(.text+0x136): undefined reference to `errno'
init/built-in.o(.text+0x163): undefined reference to `errno'
init/built-in.o(.text+0x17d): undefined reference to `errno'
init/built-in.o(.text+0x192): more undefined references to `errno' follow
make[1]: *** [.tmp_vmlinux] Error 1