I met a requirements, the executable binary must pass the checking by https://github.com/slimm609/checksec.sh,

so I enabled following build configurations for my toolchain gcc:

_D_FORTIFY_SOURCE=2  -Wl,-z,relro,-z,now -fstack-protector-all 

but it didn't output any warning msgs during the compiling, while it showed properly warning msg when i use host gcc build.

below were my build logs:
=====================================

jason@linux-server:~/tmp/test$ 
jason@linux-server:~/tmp/test$ /opt/buildroot-gcc463/usr/bin/mipsel-buildroot-linux-uclibc-gcc -Wall -O2 -D_FORTIFY_SOURCE=2  -Wl,-z,relro,-z,now -fstack-protector-all -fpie -pie test.c -o testjason 

there were no any warning output.

While in host x86 gcc:
jason@linux-server:~/tmp/test$ 
jason@linux-server:~/tmp/test$ gcc  -Wall -O2 -D_FORTIFY_SOURCE=2  -Wl,-z,relro,-z,now -fstack-protector-all -fpie -pie test.c -o testjason 
In file included from /usr/include/string.h:640:0,
                 from test.c:2:
In function ‘memcpy’,
    inlined from ‘main’ at test.c:28:8:
/usr/include/x86_64-linux-gnu/bits/string3.h:51:3: warning: call to __builtin___memcpy_chk will always overflow destination buffer [enabled by default]
   return __builtin___memcpy_chk (__dest, __src, __len, __bos0 (__dest));
   ^
In function ‘memset’,
    inlined from ‘main’ at test.c:35:8:
/usr/include/x86_64-linux-gnu/bits/string3.h:84:3: warning: call to __builtin___memset_chk will always overflow destination buffer [enabled by default]
   return __builtin___memset_chk (__dest, __ch, __len, __bos0 (__dest));
   ^
jason@linux-server:~/tmp/test$ 
=======================================


for build toolchain, I enabled libssp only in package/gcc/gcc.mk file:

HOST_GCC_COMMON_CONF_OPT = \
        --target=$(GNU_TARGET_NAME) \
        --with-sysroot=$(STAGING_DIR) \
        --disable-__cxa_atexit \
        --with-gnu-ld \
        --enable-libssp \
        --disable-multilib \
        --with-gmp=$(HOST_DIR)/usr \
        --with-mpfr=$(HOST_DIR)/usr