_FORTIFY_SOURCE=3 performance
Posted: Jan 05, 2023, 16:28So early last year I finished implemented everything needed for a fully working _FORTIFY_SOURCE=3 so that disrtributions can use it out of the box. OpenSUSE adopted it almost immediately and Gentoo started the work of adding it to their hardened profile. I proposed to make it the default for Fedora 38 after some tests but people quoted to me this blog post that some guy wrote, telling me that there’s a performance issue. Since my explanations and clarifications in the Fedora wiki or on the Fedora devel list is not sufficient (the feature was approved but the “_FORTIFY_SOURCE=3 has performance overhead” claims don’t seem to stop), here’s a blog post for a blog post, stating conclusively that the performance issue is theoretical and overstated, the guy didn’t know what he was talking about when he wrote it.
That guy is working on a clarification blog post of his own, describing in some more detail why the concern is overblown but he has to jump through editorial hoops of a multi-billion dollar corporation that pays his salary, so his apology to me is going to take a while. Whenever he gets to publish his work, I’ll link it here so that it’s two blog posts against one. Take that!