Module Name: src
Committed By: riastradh
Date: Thu Dec 22 13:54:57 UTC 2022
Modified Files:
src/sys/net: route.c
Log Message:
route(4): Work around deadlock in rt_free wait path.
PR kern/56844
XXX pullup-8
XXX pullup-9
XXX pullup-10
To generate a diff of this commit:
cvs rdiff -u -r1.235 -r1.236 src/sys/net/route.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/net/route.c
diff -u src/sys/net/route.c:1.235 src/sys/net/route.c:1.236
--- src/sys/net/route.c:1.235 Fri Nov 25 08:39:32 2022
+++ src/sys/net/route.c Thu Dec 22 13:54:57 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: route.c,v 1.235 2022/11/25 08:39:32 knakahara Exp $ */
+/* $NetBSD: route.c,v 1.236 2022/12/22 13:54:57 riastradh Exp $ */
/*-
* Copyright (c) 1998, 2008 The NetBSD Foundation, Inc.
@@ -97,7 +97,7 @@
#endif
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: route.c,v 1.235 2022/11/25 08:39:32 knakahara Exp $");
+__KERNEL_RCSID(0, "$NetBSD: route.c,v 1.236 2022/12/22 13:54:57 riastradh Exp $");
#include <sys/param.h>
#ifdef RTFLUSH_DEBUG
@@ -642,8 +642,17 @@ static bool
rt_wait_ok(void)
{
+ /*
+ * This originally returned !cpu_softintr_p(), but that doesn't
+ * work: the caller may hold a lock (probably softnet lock)
+ * that a softint is waiting for, in which case waiting here
+ * would cause a deadlock. See https://gnats.netbsd.org/56844
+ * for details. For now, until the locking paths are sorted
+ * out, we just disable the waiting option altogether and
+ * always defer to workqueue.
+ */
KASSERT(!cpu_intr_p());
- return !cpu_softintr_p();
+ return false;
}
void
