Messages in this thread Patch in this message | | | Date | Fri, 09 Oct 2009 16:34:41 -0700 | From | Greg KH <> | Subject | [patch 30/37] tcp: fix CONFIG_TCP_MD5SIG + CONFIG_PREEMPT timer BUG() |
| |
2.6.31-stable review patch. If anyone has any objections, please let us know.
------------------ From: Robert Varga <nite@hq.alert.sk>
[ Upstream commit 657e9649e745b06675aa5063c84430986cdc3afa ]
I have recently came across a preemption imbalance detected by:
<4>huh, entered ffffffff80644630 with preempt_count 00000102, exited with 00000101? <0>------------[ cut here ]------------ <2>kernel BUG at /usr/src/linux/kernel/timer.c:664! <0>invalid opcode: 0000 [1] PREEMPT SMP
with ffffffff80644630 being inet_twdr_hangman().
This appeared after I enabled CONFIG_TCP_MD5SIG and played with it a bit, so I looked at what might have caused it.
One thing that struck me as strange is tcp_twsk_destructor(), as it calls tcp_put_md5sig_pool() -- which entails a put_cpu(), causing the detected imbalance. Found on 2.6.23.9, but 2.6.31 is affected as well, as far as I can tell.
Signed-off-by: Robert Varga <nite@hq.alert.sk> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> --- net/ipv4/tcp_minisocks.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/net/ipv4/tcp_minisocks.c +++ b/net/ipv4/tcp_minisocks.c @@ -363,7 +363,7 @@ void tcp_twsk_destructor(struct sock *sk #ifdef CONFIG_TCP_MD5SIG struct tcp_timewait_sock *twsk = tcp_twsk(sk); if (twsk->tw_md5_keylen) - tcp_put_md5sig_pool(); + tcp_free_md5sig_pool(); #endif }
| |