[src/trunk]: src/sys/arch/arm/cortex Avoid undefined behaviour. Detected by ...

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

details:   https://anonhg.NetBSD.org/src/rev/7f5dab40036d
branches:  trunk
changeset: 935884:7f5dab40036d
user:      skrll <skrll%NetBSD.org@localhost>
date:      Sun Jul 12 13:33:44 2020 +0000

description:
Avoid undefined behaviour.  Detected by KUBSAN.

diffstat:

 sys/arch/arm/cortex/gic.c |  12 ++++++------
 1 files changed, 6 insertions(+), 6 deletions(-)

diffs (34 lines):

diff -r 72bd3dc6c9ba -r 7f5dab40036d sys/arch/arm/cortex/gic.c
--- a/sys/arch/arm/cortex/gic.c Sun Jul 12 13:12:17 2020 +0000
+++ b/sys/arch/arm/cortex/gic.c Sun Jul 12 13:33:44 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: gic.c,v 1.39 2020/04/13 12:14:04 jmcneill Exp $        */
+/*     $NetBSD: gic.c,v 1.40 2020/07/12 13:33:44 skrll Exp $   */
 /*-
  * Copyright (c) 2012 The NetBSD Foundation, Inc.
  * All rights reserved.
@@ -34,7 +34,7 @@
 #define _INTR_PRIVATE
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: gic.c,v 1.39 2020/04/13 12:14:04 jmcneill Exp $");
+__KERNEL_RCSID(0, "$NetBSD: gic.c,v 1.40 2020/07/12 13:33:44 skrll Exp $");
 
 #include <sys/param.h>
 #include <sys/bus.h>
@@ -430,11 +430,11 @@
                 * There are 16 irqs per CFG register.  10=EDGE 00=LEVEL
                 */
                uint32_t new_cfg = cfg;
-               uint32_t old_cfg = (cfg >> twopair_shift) & 3;
-               if (is->is_type == IST_LEVEL && (old_cfg & 2) != 0) {
-                       new_cfg &= ~(3 << twopair_shift);
+               uint32_t old_cfg = (cfg >> twopair_shift) & __BITS(1, 0);
+               if (is->is_type == IST_LEVEL && (old_cfg & __BIT(1)) != 0) {
+                       new_cfg &= ~(__BITS(1, 0) << twopair_shift);
                } else if (is->is_type == IST_EDGE && (old_cfg & 2) == 0) {
-                       new_cfg |= 2 << twopair_shift;
+                       new_cfg |= __BIT(1) << twopair_shift;
                }
                if (new_cfg != cfg) {
                        gicd_write(sc, cfg_reg, new_cfg);