On 07/11/2018 09:07 AM, Yu-cheng Yu wrote: >> Why do we need to disallow this? AFAICT the worst that can happen is >> that a process wrecks itself, so what? > Agree. I will remove the patch. No so quick. :) We still need to find out a way to handle things that ask for an mprotect() which is incompatible with shadow stacks. PROT_READ without PROT_WRITE comes to mind. We also need to be careful that we don't copy-on-write/copy-on-access pages which fault on PROT_NONE. I *think* it'll get done correctly but we have to be sure. BTW, where are all the selftests for this code? We're slowly building up a list of pathological things that need to get tested. I don't think this can or should get merged before we have selftests.