compiling MTD error

[truename]

Hello,
     My armlinux kernel version is 2.4.18 rmk6. MTD source code
is downloaded form CVS and added to kernel tree using patch.sh.When I compiled the kernel compiler reported info as follow:

drivers/mtd/mtdlink.o:In function 'put_mtd_device':
/home/linux/drivers/mtd/mtdcore.c:225:undefined reference 'BUG_ON'
drivers/mtd/mtdlink.o:In function 'mtdblock_writesect':
/home/linux/drivers/mtd/mtdblock.c:251:undefined reference to 'unlikely'
drivers/mtd/mtdlink.o:In function 'mtd_blktrans_thread':
/home/linux/drivers/mtd/mtd/mtd_blkdevs-24.c:180:undefined reference to 'BUG_ON'
     I have used grep searching the kernel tree ,but can not find  where
defined 'BUG_ON' and 'unlikely'.
Thanks.
Gavin