The Object Size Checking (-D_FORTIFY_SOURCE=*) functionality provides
wrappers around functions suspectible to buffer overflows. While
independent from Stack Smashing Protection (-fstack-protector*), they
are often used and implemented together.
While GCC also provides an implementation in libssp, it is completely
broken (CVE-2016-4973, RHBZ#1324759) and seemingly unfixable, as there
is no reliable way for a preprocessor macro to trigger a link flag.
Therefore, adding this here is necessary to make it work.
Note that this does require building gcc with --disable-libssp and
gcc_cv_libc_provides_ssp=yes.
Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>
3e8fc7d9f2