GCC 9 Looks Set To Remove Intel MPX Support

Last year we reported on GCC deprecating Intel Memory Protection Extensions (MPX) and now it looks like with GCC 9 they will be dropping the support entirely.

Intel Memory Protection Extensions is a security feature present since Skylake for checking pointer references at run-time to avoid buffer overflows. Intel MPX support was plumbed through the Linux stack in recent years, but the GCC support has fallen a bit apart. Developers from the likes of Red Hat and SUSE are more interested now in dropping the code to reduce the maintenance burden although Intel developers have contributed patches from time-to-time.

Martin Liška of SUSE today sent out a patch to remove MPX support while keeping the relevant MPX options present but as no operation.

The GCC 8 code is branched for the GCC 8.1 release next week while GCC 9.0 is on master for new feature development and will debut next year with MPX support removed unless there is a push to revive this seemingly seldom used security feature.