svn commit: r265931 - head/sys/kern

[Don Lewis]

Author: truckman
Date: Mon May 12 20:22:42 2014
New Revision: 265931
URL: http://svnweb.freebsd.org/changeset/base/265931

Log:
  Be even more paranoid about overflow.
  
  Requested by:	ache

Modified:
  head/sys/kern/subr_rman.c

Modified: head/sys/kern/subr_rman.c
==============================================================================
--- head/sys/kern/subr_rman.c	Mon May 12 20:19:40 2014	(r265930)
+++ head/sys/kern/subr_rman.c	Mon May 12 20:22:42 2014	(r265931)
@@ -466,8 +466,8 @@ rman_reserve_resource_bound(struct rman 
 	}
 
 	amask = (1ul << RF_ALIGNMENT(flags)) - 1;
-	if (start + amask < start) {
-		DPRINTF(("start+amask wrapped around\n"));
+	if (start > ULONG_MAX - amask) {
+		DPRINTF(("start+amask would wrap around\n"));
 		goto out;
 	}
 
@@ -487,8 +487,8 @@ rman_reserve_resource_bound(struct rman 
 			    s->r_start, end));
 			break;
 		}
-		if (s->r_start + amask < s->r_start) {
-			DPRINTF(("s->r_start (%#lx) + amask (%#lx) wrapped\n",
+		if (s->r_start > ULONG_MAX - amask) {
+			DPRINTF(("s->r_start (%#lx) + amask (%#lx) too large\n",
 			    s->r_start, amask));
 			break;
 		}