svn commit: r266432 - stable/8/sys/kern

[Don Lewis]

Author: truckman
Date: Mon May 19 07:49:09 2014
New Revision: 266432
URL: http://svnweb.freebsd.org/changeset/base/266432

Log:
  MFC r265931
  
  Be even more paranoid about overflow.
  
  Requested by:   ache

Modified:
  stable/8/sys/kern/subr_rman.c
Directory Properties:
  stable/8/sys/   (props changed)
  stable/8/sys/kern/   (props changed)

Modified: stable/8/sys/kern/subr_rman.c
==============================================================================
--- stable/8/sys/kern/subr_rman.c	Mon May 19 07:46:03 2014	(r266431)
+++ stable/8/sys/kern/subr_rman.c	Mon May 19 07:49:09 2014	(r266432)
@@ -461,8 +461,8 @@ 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;
 	}
 
@@ -482,8 +482,8 @@ 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;
 		}