Re: Fatal page fault in cbq_enqueue()

[christos%astron.com@localhost (Christos Zoulas)]

In article <20170127111545.GB9450@slave.private>,
Paul Ripke  <stix%stix.id.au@localhost> wrote:
>Still happening, although not as often. Maybe the hot weather helps...
>
>I've got a core this time, on amd64 7.0_STABLE as of 2016-10-12.

How about this? At least you'll not crash....

christos

Index: altq_classq.h
===================================================================
RCS file: /cvsroot/src/sys/altq/altq_classq.h,v
retrieving revision 1.7
diff -u -u -r1.7 altq_classq.h
--- altq_classq.h	12 Oct 2006 19:59:08 -0000	1.7
+++ altq_classq.h	27 Jan 2017 18:10:12 -0000
@@ -108,9 +108,9 @@
 {
 	struct mbuf  *m, *m0;
 
-	if ((m = qtail(q)) == NULL)
+	if ((m = qtail(q)) == NULL || (m0 = m->m_nextpkt) == NULL)
 		return (NULL);
-	if ((m0 = m->m_nextpkt) != m)
+	if (m0 != m)
 		m->m_nextpkt = m0->m_nextpkt;
 	else
 		qtail(q) = NULL;