[src/trunk]: src/sys/kern Avoid Undefined Behavior in pr_item_notouch_get()

[kamil <kamil%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/13b000f9fa42
branches:  trunk
changeset: 833628:13b000f9fa42
user:      kamil <kamil%NetBSD.org@localhost>
date:      Wed Jul 04 01:42:37 2018 +0000

description:
Avoid Undefined Behavior in pr_item_notouch_get()

Change the type of left shifted integer from signed to unsigned.

sys/kern/subr_pool.c:274:13, left shift of 1 by 31 places cannot be represented in type 'int'

Detected with Kernel Undefined Behavior Sanitizer.

Reported by <Harry Pantazis>

diffstat:

 sys/kern/subr_pool.c |  6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

diffs (27 lines):

diff -r f314f2ff2167 -r 13b000f9fa42 sys/kern/subr_pool.c
--- a/sys/kern/subr_pool.c      Wed Jul 04 01:17:32 2018 +0000
+++ b/sys/kern/subr_pool.c      Wed Jul 04 01:42:37 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: subr_pool.c,v 1.221 2018/01/12 18:54:37 para Exp $     */
+/*     $NetBSD: subr_pool.c,v 1.222 2018/07/04 01:42:37 kamil Exp $    */
 
 /*-
  * Copyright (c) 1997, 1999, 2000, 2002, 2007, 2008, 2010, 2014, 2015
@@ -33,7 +33,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_pool.c,v 1.221 2018/01/12 18:54:37 para Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_pool.c,v 1.222 2018/07/04 01:42:37 kamil Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_ddb.h"
@@ -271,7 +271,7 @@
 
                        bit--;
                        idx = (i * BITMAP_SIZE) + bit;
-                       mask = 1 << bit;
+                       mask = 1U << bit;
                        KASSERT((bitmap[i] & mask) != 0);
                        bitmap[i] &= ~mask;
                        break;