CVS commit: src/sys/kern

[Kamil Rytarowski]

Module Name:    src
Committed By:   kamil
Date:           Tue Jul  3 23:11:06 UTC 2018

Modified Files:
        src/sys/kern: kern_descrip.c

Log Message:
Avoid unportable signed integer left shift in fd_copy()

Detected with Kernel Undefined Behavior Sanitizer.

There were at least a single place reported, for consistency fix all the
left bit shift operations.
sys/kern/kern_descrip.c:1492:3, left shift of 1 by 31 places cannot be 
represented in type 'int'
sys/kern/kern_descrip.c:1493:28, left shift of 1 by 31 places cannot be 
represented in type 'int'

Reported by <Harry Pantazis>


To generate a diff of this commit:
cvs rdiff -u -r1.233 -r1.234 src/sys/kern/kern_descrip.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.


Modified files:

Index: src/sys/kern/kern_descrip.c
diff -u src/sys/kern/kern_descrip.c:1.233 src/sys/kern/kern_descrip.c:1.234
--- src/sys/kern/kern_descrip.c:1.233	Tue Jul  3 22:49:51 2018
+++ src/sys/kern/kern_descrip.c	Tue Jul  3 23:11:06 2018
@@ -1,4 +1,4 @@
-/*	$NetBSD: kern_descrip.c,v 1.233 2018/07/03 22:49:51 kamil Exp $	*/
+/*	$NetBSD: kern_descrip.c,v 1.234 2018/07/03 23:11:06 kamil Exp $	*/
 
 /*-
  * Copyright (c) 2008, 2009 The NetBSD Foundation, Inc.
@@ -70,7 +70,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_descrip.c,v 1.233 2018/07/03 22:49:51 kamil Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_descrip.c,v 1.234 2018/07/03 23:11:06 kamil Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -1489,13 +1489,13 @@ fd_copy(void)
 
 		/* Fix up bitmaps. */
 		j = i >> NDENTRYSHIFT;
-		KASSERT((newfdp->fd_lomap[j] & (1 << (i & NDENTRYMASK))) == 0);
-		newfdp->fd_lomap[j] |= 1 << (i & NDENTRYMASK);
+		KASSERT((newfdp->fd_lomap[j] & (1U << (i & NDENTRYMASK))) == 0);
+		newfdp->fd_lomap[j] |= 1U << (i & NDENTRYMASK);
 		if (__predict_false(newfdp->fd_lomap[j] == ~0)) {
 			KASSERT((newfdp->fd_himap[j >> NDENTRYSHIFT] &
-			    (1 << (j & NDENTRYMASK))) == 0);
+			    (1U << (j & NDENTRYMASK))) == 0);
 			newfdp->fd_himap[j >> NDENTRYSHIFT] |=
-			    1 << (j & NDENTRYMASK);
+			    1U << (j & NDENTRYMASK);
 		}
 		newlast = i;
 	}