[src/trunk]: src/sys/dev/ata don't touch the queue structure in ata_queue_act...

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

details:   https://anonhg.NetBSD.org/src/rev/27e94dd9898e
branches:  trunk
changeset: 836807:27e94dd9898e
user:      jdolecek <jdolecek%NetBSD.org@localhost>
date:      Wed Nov 07 17:05:54 2018 +0000

description:
don't touch the queue structure in ata_queue_active() if atabus is already
detached from the channel

fixes panic on null pointer derefence during shutdown reported privately
by Launey Thomas

diffstat:

 sys/dev/ata/ata_subr.c |  7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)

diffs (28 lines):

diff -r 4808a672708f -r 27e94dd9898e sys/dev/ata/ata_subr.c
--- a/sys/dev/ata/ata_subr.c    Wed Nov 07 09:59:12 2018 +0000
+++ b/sys/dev/ata/ata_subr.c    Wed Nov 07 17:05:54 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: ata_subr.c,v 1.7 2018/10/22 20:13:47 jdolecek Exp $    */
+/*     $NetBSD: ata_subr.c,v 1.8 2018/11/07 17:05:54 jdolecek Exp $    */
 
 /*
  * Copyright (c) 1998, 2001 Manuel Bouyer.  All rights reserved.
@@ -25,7 +25,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: ata_subr.c,v 1.7 2018/10/22 20:13:47 jdolecek Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ata_subr.c,v 1.8 2018/11/07 17:05:54 jdolecek Exp $");
 
 #include "opt_ata.h"
 
@@ -364,6 +364,9 @@
 {
        struct ata_queue *chq = chp->ch_queue;
 
+       if (chp->ch_flags & ATACH_DETACHED)
+               return 0;
+
        return chq->active_xfers_used;
 }