v4.19.13 snapshot.
diff --git a/arch/powerpc/include/asm/exec.h b/arch/powerpc/include/asm/exec.h
new file mode 100644
index 0000000..92cac48
--- /dev/null
+++ b/arch/powerpc/include/asm/exec.h
@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 1999 Cort Dougan <cort@cs.nmt.edu>
+ */
+#ifndef _ASM_POWERPC_EXEC_H
+#define _ASM_POWERPC_EXEC_H
+
+extern unsigned long arch_align_stack(unsigned long sp);
+
+#endif /* _ASM_POWERPC_EXEC_H */