//go:nosplit
func syscall_dup2child(old, new uintptr) (val, err uintptr) {
	val, err = syscall2(&libc_dup2, old, new)
	return
}

//go:linkname syscall_execve syscall.execve
//go:nosplit
func syscall_execve(path, argv, envp uintptr) (err uintptr) {
	_, err = syscall3(&libc_execve, path, argv, envp)
	return
}

// like exit, but must not split stack, for fork.
//

//go:nosplit
//go:linkname syscall_dup2
func syscall_dup2(oldfd, newfd uintptr) (val, err uintptr) {
	return syscall_fcntl(oldfd, _F_DUP2FD, newfd)
}

//go:nosplit
//go:linkname syscall_execve
//go:cgo_unsafe_args
func syscall_execve(path, argv, envp uintptr) (err uintptr) {
	call := libcall{
		fn:   uintptr(unsafe.Pointer(&libc_execve)),
		n:    3,
		args: uintptr(unsafe.Pointer(&path)),
	}