VDSO64_SYMBOL
rp = VDSO64_SYMBOL(current, sigtramp_rt);
rp = VDSO64_SYMBOL(current, restart_syscall);
regs_set_return_ip(regs, VDSO64_SYMBOL(tsk->mm->context.vdso, sigtramp_rt64));
nip == VDSO64_SYMBOL(current->mm->context.vdso, sigtramp_rt64))