kernelソースを利用するportsをリストアップしてみました。
kernelを更新したら以下の中でインストールされている物があれば再起動前に合わせて更新することをおすすめします。
audio/aureal-kmod audio/oss chinese/big5width chinese/telnet comms/hso-kmod comms/ib-kmod comms/uarduno comms/uhso-kmod comms/umcs7840 devel/linux_kdump devel/linux-js devel/linuxthreads emulators/kqemu-kmod emulators/kqemu-kmod-devel emulators/parallels-tools emulators/rtc emulators/virtualbox-ose emulators/virtualbox-ose-additions emulators/virtualbox-ose-kmod emulators/virtualbox-ose-kmod-legacy emulators/virtualbox-ose-legacy emulators/vmware-guestd4 emulators/vmware-guestd5 emulators/vmware-guestd6 graphics/kix-kmod graphics/plasma-kmod misc/dahdi-kmod multimedia/cuse4bsd-kmod multimedia/cx88 multimedia/linux_dvbwrapper-kmod multimedia/linux_v4l2wrapper-kmod multimedia/ptx-kmod multimedia/pvr250 multimedia/pvrxxx multimedia/pwcbsd multimedia/sms1xxx-kmod net-mgmt/ng_ipacct net/acx100 net/asterisk-oh323 net/bwi-firmware-kmod net/bwn-firmware-kmod net/click net/iet net/ipvs net/ipw-firmware net/ipw-firmware-kmod net/iwi-firmware net/mpd4 net/mpd5 net/ng_car net/ng_daphne net/openafs net/skyfish net/skystar2 net/ttbudget print/acroreadwrapper security/quantis security/quantis-kmod sysutils/biosfont sysutils/cciss_vol_status sysutils/devcpu sysutils/fusefs-kmod sysutils/fusefs-sshfs sysutils/graid5 sysutils/lsof sysutils/mono-kmod sysutils/pefs-kmod sysutils/pmap sysutils/scprotect sysutils/uhidd sysutils/vordog textproc/gxditview x11-drivers/input-wacom