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| author | Robert Varga <nite@hq.alert.sk> | 2009-09-15 23:49:21 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-04-01 15:52:19 -0700 |
| commit | 7224283df47b5ff9f309371b60030f07037cd51e (patch) | |
| tree | 575c190a6cd5eb6bdfa2720f94512aca87f75b1e /net | |
| parent | f02363178930a9fb73c88f88c3c347d27d62a082 (diff) | |
| download | lwn-7224283df47b5ff9f309371b60030f07037cd51e.tar.gz lwn-7224283df47b5ff9f309371b60030f07037cd51e.zip | |
tcp: fix CONFIG_TCP_MD5SIG + CONFIG_PREEMPT timer BUG()
commit 657e9649e745b06675aa5063c84430986cdc3afa upstream.
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>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/tcp_minisocks.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c index f976fc57892c..6d108fbcb7c2 100644 --- a/net/ipv4/tcp_minisocks.c +++ b/net/ipv4/tcp_minisocks.c @@ -362,7 +362,7 @@ 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 } |