Function ptrace 

#[unsafe(no_mangle)]
pub unsafe extern "C" fn ptrace(request: c_int, ...) -> c_int

Non-POSIX, see https://www.man7.org/linux/man-pages/man2/ptrace.2.html.

Provides a means by which one process (the “tracer”) may observe and control the execution of another process (the “tracee”), and examine and change the tracee’s memory and registers.

The __valist argument represents 3 arguments in this order:

• pid
• *addr
• *data

Currently only implemented on x86_64.