OPAL_ALIGN_PAD_AMOUNT: safely allow passing zero byte alignment

Signed-off-by: Joseph Schuchart <schuchart@hlrs.de>
(cherry picked from commit 67baec6)

Author: devreal

opal/include/opal/align.h

@@ -5,7 +5,7 @@
  * Copyright (c) 2004-2005 The University of Tennessee and The University
  *                         of Tennessee Research Foundation.  All rights
  *                         reserved.
- * Copyright (c) 2004-2005 High Performance Computing Center Stuttgart,
+ * Copyright (c) 2004-2020 High Performance Computing Center Stuttgart,
  *                         University of Stuttgart.  All rights reserved.
  * Copyright (c) 2004-2005 The Regents of the University of California.
  *                         All rights reserved.
@@ -22,11 +22,11 @@
 #ifndef OPAL_ALIGN_H
 #define OPAL_ALIGN_H
 
-#define OPAL_DOWN_ALIGN(x, a, t)     ((x) & ~(((t)(a) -1)))
-#define OPAL_DOWN_ALIGN_PTR(x, a, t) ((t) OPAL_DOWN_ALIGN((uintptr_t) x, a, uintptr_t))
-#define OPAL_ALIGN(x, a, t)          (((x) + ((t)(a) -1)) & ~(((t)(a) -1)))
-#define OPAL_ALIGN_PTR(x, a, t)      ((t) OPAL_ALIGN((uintptr_t) x, a, uintptr_t))
-#define OPAL_ALIGN_PAD_AMOUNT(x, s)  ((~((uintptr_t)(x)) + 1) & ((uintptr_t)(s) -1))
+#define OPAL_DOWN_ALIGN(x,a,t)       ((x) & ~(((t)(a)-1)))
+#define OPAL_DOWN_ALIGN_PTR(x,a,t)   ((t)OPAL_DOWN_ALIGN((uintptr_t)x, a, uintptr_t))
+#define OPAL_ALIGN(x,a,t)            (((x)+((t)(a)-1)) & ~(((t)(a)-1)))
+#define OPAL_ALIGN_PTR(x,a,t)        ((t)OPAL_ALIGN((uintptr_t)x, a, uintptr_t))
+#define OPAL_ALIGN_PAD_AMOUNT(x,s)   ((~((uintptr_t)(x))+1) & ((uintptr_t)(s)+(!(uintptr_t)(s))-1))
 
 #if __STDC_VERSION__ >= 201101L
 #    include <stddef.h>