Prevents the process from execveing to a different process, such as bash.
Hooks all exec* functions, as well as system and popen and the not-yet-available execveat.
Disallows the execution of execve and execveat system calls.
Also disallows all system calls we don't know exist (e.g. if new ones are added).
Also disallows all wrong-architecture syscalls (e.g. compatibility mode).
$ LD_PRELOAD=$PWD/no_execve.so sh
$ ps
$ echo $?
159