[src/trunk]: src/sys/kern initialize wc_unused to 0, to avoid writing uniniti...

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

details:   https://anonhg.NetBSD.org/src/rev/33eddad22bde
branches:  trunk
changeset: 1022729:33eddad22bde
user:      chs <chs%NetBSD.org@localhost>
date:      Tue Aug 03 20:25:43 2021 +0000

description:
initialize wc_unused to 0, to avoid writing uninitialized memory to disk.
detected by KMSAN.

diffstat:

 sys/kern/vfs_wapbl.c |  6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diffs (34 lines):

diff -r f56e6fa91815 -r 33eddad22bde sys/kern/vfs_wapbl.c
--- a/sys/kern/vfs_wapbl.c      Tue Aug 03 20:22:15 2021 +0000
+++ b/sys/kern/vfs_wapbl.c      Tue Aug 03 20:25:43 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: vfs_wapbl.c,v 1.108 2020/04/12 17:02:52 jdolecek Exp $ */
+/*     $NetBSD: vfs_wapbl.c,v 1.109 2021/08/03 20:25:43 chs Exp $      */
 
 /*-
  * Copyright (c) 2003, 2008, 2009 The NetBSD Foundation, Inc.
@@ -36,7 +36,7 @@
 #define WAPBL_INTERNAL
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vfs_wapbl.c,v 1.108 2020/04/12 17:02:52 jdolecek Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vfs_wapbl.c,v 1.109 2021/08/03 20:25:43 chs Exp $");
 
 #include <sys/param.h>
 #include <sys/bitops.h>
@@ -2559,6 +2559,7 @@
                wc->wc_type = WAPBL_WC_BLOCKS;
                wc->wc_len = blocklen;
                wc->wc_blkcount = 0;
+               wc->wc_unused = 0;
                while (bp && (wc->wc_blkcount < wl->wl_brperjblock)) {
                        /*
                         * Make sure all the physical block numbers are up to
@@ -2647,6 +2648,7 @@
                wc->wc_type = WAPBL_WC_REVOCATIONS;
                wc->wc_len = blocklen;
                wc->wc_blkcount = 0;
+               wc->wc_unused = 0;
                while (wd && (wc->wc_blkcount < wl->wl_brperjblock)) {
                        wc->wc_blocks[wc->wc_blkcount].wc_daddr =
                            wd->wd_blkno;