Hello, n...@n0.is writes:
> Hi, > > as we've long talked and not really taken action on hardening builds > I've started working on an opt-in way as last discussed in > september 2016, modifying the gnu-build-system with a > #:hardening-flags keyword. > > For my testing purposes I will use > >> CFLAGS="-fPIE -fstack-protector-all -D_FORTIFY_SOURCE=2" > LDFLAGS="-Wl,-z,now -Wl,-z,relro" > > which is used by Gentoo, but adjustments (wether to opt-in or > opt-out) will be made. The flags I use (suggested by Debian Wiki[0]) are: CPPFLAGS=-D_FORTIFY_SOURCE=2 CFLAGS=-fstack-protector-strong CXXFLAGS=-fstack-protector-strong LDFLAGS=-Wl,-z,relro,-z,now,--as-needed Also, should we use retpoline flags for all native binaries? This article[1] suggests ``applying a software mitigation (e.g., Google's Retpoline) to the hypervisor, operating system kernel, system programs and libraries, and user applications''. I've sent a patch to do so when bootstraping GCC 7 itself[2] but no reply are received yet (maybe I should have open a new bug instead of changing the title of an old bug). [0]: https://wiki.debian.org/Hardening [1]: https://security.googleblog.com/2018/01/more-details-about-mitigations-for-cpu_4.html [2]: https://debbugs.gnu.org/cgi/bugreport.cgi?bug=30111
