p_cansignal
error = p_cansignal(td, p, sig);
error = p_cansignal(td, p, sig);
error1 = p_cansignal(td, p2, rk->rk_sig);
err = p_cansignal(arg->td, p, arg->sig);
error = p_cansignal(td, p, signum);
error = p_cansignal(td, p, uap->signum);
error = p_cansignal(td, p, signum);
error = p_cansignal(td, p, uap->sig);
error = p_cansignal(td, p, uap->sig);
int p_cansignal(struct thread *td, struct proc *p, int signum);