请教一个undefined reference to错误

[wang@server linux-2.6.8.1.hyl]$ make

make[1]: "arch/i386/kernel/asm-offsets.s"是最新的。

CHK include/linux/compile.h

GEN .version

CHK include/linux/compile.h

UPD include/linux/compile.h

CC init/version.o

LD init/built-in.o

LD .tmp_vmlinux1

net/built-in.o(.init.text+0xcc5): In function `sock_ioctl':

net/socket.c:902: undefined reference to `__skb_cb_too_small_for_tcp'

make: *** [.tmp_vmlinux1] 错误 1

[wang@server linux-2.6.8.1.hyl]$


打了一个补丁之后结果出现上述错误，让我迷惑不解的是net/socket.c:902 里面没有涉
及到__skb_cb_too_small_for_tcp，而__skb_cb_too_small_for_tcp是在tcp.c中定义的
，已经写了extern void __skb_cb_too_small_for_tcp(int, int);

上网查说是是编译链接错误，但是哪里错了么？一点头绪都没有，各位大大能否给个提示，3x

ps：
__skb_cb_too_small_for_tcp这个函数的定义请见
[URL="http://www.gelato.unsw.edu.au/lxr/ident?i=__skb_cb_too_small_for_tcp"]http://www.gelato.unsw.edu.au/lxr/id..._small_for_tcp[/COLOR][/URL]