Module Name: src
Committed By: riastradh
Date: Sun Mar 13 21:32:27 UTC 2022
Modified Files:
src/sys/net: if_tun.c
Log Message:
tun(4): Reduce lock from IPL_NET to IPL_SOFTNET.
This is never taken from hardware interrupt handlers any more, as far
as I can tell -- only SOFTINT_NET soft interrupt handlers.
This avoids trying to take an adaptive lock, proc_lock, in fownsignal
while holding a spin lock. Unfortunately, it doesn't entirely fix the
problem -- proc_lock is at IPL_NONE, and is held across some not
entirely trivial computations like allocating a new pid table. So it
would really be better if we had some way to deliver SIGIO without
taking proc_lock.
Reported-by: syzbot+3dd54993d3e92e697...@syzkaller.appspotmail.com
Reported-by: syzbot+aca29415f2f0bf23f...@syzkaller.appspotmail.com
To generate a diff of this commit:
cvs rdiff -u -r1.167 -r1.168 src/sys/net/if_tun.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/if_tun.c
diff -u src/sys/net/if_tun.c:1.167 src/sys/net/if_tun.c:1.168
--- src/sys/net/if_tun.c:1.167 Sun Mar 13 21:32:15 2022
+++ src/sys/net/if_tun.c Sun Mar 13 21:32:27 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: if_tun.c,v 1.167 2022/03/13 21:32:15 riastradh Exp $ */
+/* $NetBSD: if_tun.c,v 1.168 2022/03/13 21:32:27 riastradh Exp $ */
/*
* Copyright (c) 1988, Julian Onions <j...@cs.nott.ac.uk>
@@ -19,7 +19,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_tun.c,v 1.167 2022/03/13 21:32:15 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_tun.c,v 1.168 2022/03/13 21:32:27 riastradh Exp $");
#ifdef _KERNEL_OPT
#include "opt_inet.h"
@@ -216,7 +216,7 @@ tun_init(struct tun_softc *tp, int unit)
{
tp->tun_unit = unit;
- mutex_init(&tp->tun_lock, MUTEX_DEFAULT, IPL_NET);
+ mutex_init(&tp->tun_lock, MUTEX_DEFAULT, IPL_SOFTNET);
cv_init(&tp->tun_cv, "tunread");
selinit(&tp->tun_rsel);
selinit(&tp->tun_wsel);
