* Rick Edgecombe: > + /* Only support enabling/disabling one feature at a time. */ > + if (hweight_long(features) > 1) > + return -EINVAL; This means we'll soon need three extra system calls for x86-64 process start: SHSTK, IBT, and switching off vsyscall emulation. (The latter does not need any special CPU support.) Maybe we can do something else instead to make the strace output a little bit cleaner? Thanks, Florian