* [PATCH] remove leftover rcu_read_unlock calls from __mkroute_output
@ 2010-10-08 0:48 Dimitris Michailidis
2010-10-08 4:47 ` Eric Dumazet
0 siblings, 1 reply; 3+ messages in thread
From: Dimitris Michailidis @ 2010-10-08 0:48 UTC (permalink / raw)
To: eric.dumazet, netdev
Commit "fib: RCU conversion of fib_lookup()" removed rcu_read_lock() from
__mkroute_output but left a couple of calls to rcu_read_unlock() in there.
This causes lockdep to complain that the rcu_read_unlock() call in
__ip_route_output_key causes a lock inbalance and quickly crashes the
kernel. The below fixes this for me.
Signed-off-by: Dimitris Michailidis <dm@chelsio.com>
---
net/ipv4/route.c | 6 ++----
1 files changed, 2 insertions(+), 4 deletions(-)
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 7864d0c..3888f6b 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2396,12 +2396,10 @@ static int __mkroute_output(struct rtable **result,
rth = dst_alloc(&ipv4_dst_ops);
- if (!rth) {
- rcu_read_unlock();
+ if (!rth)
return -ENOBUFS;
- }
+
in_dev_hold(in_dev);
- rcu_read_unlock();
rth->idev = in_dev;
atomic_set(&rth->dst.__refcnt, 1);
--
1.5.4
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] remove leftover rcu_read_unlock calls from __mkroute_output
2010-10-08 0:48 [PATCH] remove leftover rcu_read_unlock calls from __mkroute_output Dimitris Michailidis
@ 2010-10-08 4:47 ` Eric Dumazet
2010-10-08 17:51 ` David Miller
0 siblings, 1 reply; 3+ messages in thread
From: Eric Dumazet @ 2010-10-08 4:47 UTC (permalink / raw)
To: Dimitris Michailidis; +Cc: netdev
Le jeudi 07 octobre 2010 à 17:48 -0700, Dimitris Michailidis a écrit :
> Commit "fib: RCU conversion of fib_lookup()" removed rcu_read_lock() from
> __mkroute_output but left a couple of calls to rcu_read_unlock() in there.
> This causes lockdep to complain that the rcu_read_unlock() call in
> __ip_route_output_key causes a lock inbalance and quickly crashes the
> kernel. The below fixes this for me.
>
> Signed-off-by: Dimitris Michailidis <dm@chelsio.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Thanks Dimitris !
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] remove leftover rcu_read_unlock calls from __mkroute_output
2010-10-08 4:47 ` Eric Dumazet
@ 2010-10-08 17:51 ` David Miller
0 siblings, 0 replies; 3+ messages in thread
From: David Miller @ 2010-10-08 17:51 UTC (permalink / raw)
To: eric.dumazet; +Cc: dm, netdev
From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Fri, 08 Oct 2010 06:47:58 +0200
> Le jeudi 07 octobre 2010 à 17:48 -0700, Dimitris Michailidis a écrit :
>> Commit "fib: RCU conversion of fib_lookup()" removed rcu_read_lock() from
>> __mkroute_output but left a couple of calls to rcu_read_unlock() in there.
>> This causes lockdep to complain that the rcu_read_unlock() call in
>> __ip_route_output_key causes a lock inbalance and quickly crashes the
>> kernel. The below fixes this for me.
>>
>> Signed-off-by: Dimitris Michailidis <dm@chelsio.com>
>
> Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Applied, thanks everyone.
^ permalink raw reply [flat|nested] 3+ messages in thread
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2010-10-08 0:48 [PATCH] remove leftover rcu_read_unlock calls from __mkroute_output Dimitris Michailidis
2010-10-08 4:47 ` Eric Dumazet
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