Isn't this ability basically already provided via ptrace? The tracer can mutate syscall arguments, mutate syscall return values, or even block syscalls. The pri

Isn't this ability basically already provided via ptrace? The tracer can mutate syscall arguments, mutate syscall return values, or even block syscalls. The primitives ptrace provides should be sufficient to implement something like this. That's basically how strace is implemented anyways.