From: Herbert Xu <herbert@gondor.apana.org.au>
To: Ingo Molnar <mingo@elte.hu>
Cc: davem@redhat.com, linux-kernel@vger.kernel.org,
netdev@vger.kernel.org,
YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Subject: Re: [lock validator] inet6_destroy_sock(): soft-safe -> soft-unsafe lock dependency
Date: Wed, 1 Feb 2006 21:42:14 +1100 [thread overview]
Message-ID: <20060201104214.GA9085@gondor.apana.org.au> (raw)
In-Reply-To: <20060131212432.GA18812@elte.hu>
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On Tue, Jan 31, 2006 at 10:24:32PM +0100, Ingo Molnar wrote:
>
> [<c04de9e8>] _write_lock+0x8/0x10
> [<c0499015>] inet6_destroy_sock+0x25/0x100
> [<c04b8672>] tcp_v6_destroy_sock+0x12/0x20
> [<c046bbda>] inet_csk_destroy_sock+0x4a/0x150
> [<c047625c>] tcp_rcv_state_process+0xd4c/0xdd0
> [<c047d8e9>] tcp_v4_do_rcv+0xa9/0x340
> [<c047eabb>] tcp_v4_rcv+0x8eb/0x9d0
OK this is definitely broken. We should never touch the dst lock in
softirq context. Since inet6_destroy_sock may be called from that
context due to the asynchronous nature of sockets, we can't take the
lock there.
In fact this sk_dst_reset is totally redundant since all IPv6 sockets
use inet_sock_destruct as their socket destructor which always cleans
up the dst anyway. So the solution is to simply remove the call.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Cheers,
--
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
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diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -369,12 +369,6 @@ int inet6_destroy_sock(struct sock *sk)
struct sk_buff *skb;
struct ipv6_txoptions *opt;
- /*
- * Release destination entry
- */
-
- sk_dst_reset(sk);
-
/* Release rx options */
if ((skb = xchg(&np->pktoptions, NULL)) != NULL)
next prev parent reply other threads:[~2006-02-01 10:42 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-01-27 0:18 [lock validator] net/ipv4/fib_hash.c: illegal {enabled-softirqs} -> {used-in-softirq} usage? Ingo Molnar
2006-01-27 1:41 ` Herbert Xu
2006-01-28 15:22 ` [lock validator] inet6_destroy_sock(): soft-safe -> soft-unsafe lock dependency Ingo Molnar
2006-01-28 15:44 ` Ingo Molnar
2006-01-31 10:27 ` Herbert Xu
2006-01-31 10:43 ` David S. Miller
2006-01-31 11:21 ` Ingo Molnar
2006-02-01 13:32 ` Ingo Molnar
2006-02-01 20:26 ` Herbert Xu
2006-02-02 7:46 ` Ingo Molnar
2006-02-02 8:48 ` Herbert Xu
2006-02-02 9:04 ` David S. Miller
2006-02-02 10:54 ` Ingo Molnar
2006-02-02 11:27 ` Ingo Molnar
2006-02-02 12:19 ` Herbert Xu
2006-02-02 12:17 ` Herbert Xu
2006-02-02 13:54 ` Ingo Molnar
2006-01-31 21:24 ` Ingo Molnar
2006-01-31 22:06 ` Herbert Xu
2006-02-01 10:42 ` Herbert Xu [this message]
2006-02-01 11:13 ` Ingo Molnar
2006-02-03 1:01 ` David S. Miller
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