drivers/isdn/vmlinux-obj.o: In function `isdn_ppp_ioctl':
drivers/isdn/vmlinux-obj.o(.text+0xe64e): undefined reference to `sk_chk_filter'
drivers/isdn/vmlinux-obj.o: In function `isdn_ppp_push_higher':
drivers/isdn/vmlinux-obj.o(.text+0xf2e5): undefined reference to `sk_run_filter'
drivers/isdn/vmlinux-obj.o(.text+0xf32d): undefined reference to `sk_run_filter'
drivers/isdn/vmlinux-obj.o: In function `isdn_ppp_xmit':
drivers/isdn/vmlinux-obj.o(.text+0xf729): undefined reference to `sk_run_filter'
drivers/isdn/vmlinux-obj.o(.text+0xf78e): undefined reference to `sk_run_filter'
drivers/isdn/vmlinux-obj.o: In function `isdn_ppp_autodial_filter':
drivers/isdn/vmlinux-obj.o(.text+0xfcba): undefined reference to `sk_run_filter'
drivers/isdn/vmlinux-obj.o(.text+0xfce4): more undefined references to `sk_run_f
ilter' follow
make: *** [vmlinux] Error 1