Poky proposes some default security flags to be used at build time (see Yocto Mega Manual).

A discussion has been led in the mailing list and finally the flags were added in this commit.

But when migrating to Poky 2.1/krogoth, the flags were removed in this commit.

We should consider re-enabling the security flags.

Also, some overrides in meta-agl/meta-agl-distro/conf/distro/poky-agl.conf may not be required anymore:

# required overrides, upstreamed but not merged yet:
# http://lists.openembedded.org/pipermail/openembedded-devel/2016-June/107727.html
#SECURITY_CFLAGS_pn-llvm3.3 = "${SECURITY_NO_PIE_CFLAGS}"
SECURITY_STRINGFORMAT_pn-gpm = ""
SECURITY_CFLAGS_pn-libdbus-c++ = ""
SECURITY_LDFLAGS_pn-libdbus-c++ = ""