SSP_CFLAGS for kernel

Hi!

I set:

/etc/src.conf:
WITH_SSP=

/etc/make.conf:
SSP_CFLAGS=-fstack-protector-all
WITH_SSP_PORTS=yes


But in /usr/src/sys/conf/kern.mk:

...
#
# GCC SSP support
#
.if ${MK_SSP} != "no" && \
    ${MACHINE_CPUARCH} != "arm" && ${MACHINE_CPUARCH} != "mips"
CFLAGS+=	-fstack-protector
.endif
...


Is there should be some thing like in /usr/src/share/mk/bsd.sys.mk:

SSP_CFLAGS?=	-fstack-protector
CFLAGS+=	${SSP_CFLAGS}

???


PS: /usr/ports/UPDATING
"The default SSP_CLFAGS is -fstack-protector, but -fstack-protector-all"
should be:
"The default SSP_CFLAGS is -fstack-protector, but -fstack-protector-all"