diff options
author | Denis V. Lunev <den@openvz.org> | 2008-08-23 11:43:33 (GMT) |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2008-08-23 11:43:33 (GMT) |
commit | fdc0bde90a689b9145f2b6f271c03f4c99d09667 (patch) | |
tree | f29db0a155cee7349f20862d0e1601a5696979df /net/ipv4/icmp.c | |
parent | f6e0b239a2657ea8cb67f0d83d0bfdbfd19a481b (diff) | |
download | linux-fdc0bde90a689b9145f2b6f271c03f4c99d09667.tar.xz |
icmp: icmp_sk() should not use smp_processor_id() in preemptible code
Pass namespace into icmp_xmit_lock, obtain socket inside and return
it as a result for caller.
Thanks Alexey Dobryan for this report:
Steps to reproduce:
CONFIG_PREEMPT=y
CONFIG_DEBUG_PREEMPT=y
tracepath <something>
BUG: using smp_processor_id() in preemptible [00000000] code: tracepath/3205
caller is icmp_sk+0x15/0x30
Pid: 3205, comm: tracepath Not tainted 2.6.27-rc4 #1
Call Trace:
[<ffffffff8031af14>] debug_smp_processor_id+0xe4/0xf0
[<ffffffff80409405>] icmp_sk+0x15/0x30
[<ffffffff8040a17b>] icmp_send+0x4b/0x3f0
[<ffffffff8025a415>] ? trace_hardirqs_on_caller+0xd5/0x160
[<ffffffff8025a4ad>] ? trace_hardirqs_on+0xd/0x10
[<ffffffff8023a475>] ? local_bh_enable_ip+0x95/0x110
[<ffffffff804285b9>] ? _spin_unlock_bh+0x39/0x40
[<ffffffff8025a26c>] ? mark_held_locks+0x4c/0x90
[<ffffffff8025a4ad>] ? trace_hardirqs_on+0xd/0x10
[<ffffffff8025a415>] ? trace_hardirqs_on_caller+0xd5/0x160
[<ffffffff803e91b4>] ip_fragment+0x8d4/0x900
[<ffffffff803e7030>] ? ip_finish_output2+0x0/0x290
[<ffffffff803e91e0>] ? ip_finish_output+0x0/0x60
[<ffffffff803e6650>] ? dst_output+0x0/0x10
[<ffffffff803e922c>] ip_finish_output+0x4c/0x60
[<ffffffff803e92e3>] ip_output+0xa3/0xf0
[<ffffffff803e68d0>] ip_local_out+0x20/0x30
[<ffffffff803e753f>] ip_push_pending_frames+0x27f/0x400
[<ffffffff80406313>] udp_push_pending_frames+0x233/0x3d0
[<ffffffff804067d1>] udp_sendmsg+0x321/0x6f0
[<ffffffff8040d155>] inet_sendmsg+0x45/0x80
[<ffffffff803b967f>] sock_sendmsg+0xdf/0x110
[<ffffffff8024a100>] ? autoremove_wake_function+0x0/0x40
[<ffffffff80257ce5>] ? validate_chain+0x415/0x1010
[<ffffffff8027dc10>] ? __do_fault+0x140/0x450
[<ffffffff802597d0>] ? __lock_acquire+0x260/0x590
[<ffffffff803b9e55>] ? sockfd_lookup_light+0x45/0x80
[<ffffffff803ba50a>] sys_sendto+0xea/0x120
[<ffffffff80428e42>] ? _spin_unlock_irqrestore+0x42/0x80
[<ffffffff803134bc>] ? __up_read+0x4c/0xb0
[<ffffffff8024e0c6>] ? up_read+0x26/0x30
[<ffffffff8020b8bb>] system_call_fastpath+0x16/0x1b
icmp6_sk() is similar.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/icmp.c')
-rw-r--r-- | net/ipv4/icmp.c | 22 |
1 files changed, 14 insertions, 8 deletions
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c index 8605586..55c355e 100644 --- a/net/ipv4/icmp.c +++ b/net/ipv4/icmp.c @@ -204,18 +204,22 @@ static struct sock *icmp_sk(struct net *net) return net->ipv4.icmp_sk[smp_processor_id()]; } -static inline int icmp_xmit_lock(struct sock *sk) +static inline struct sock *icmp_xmit_lock(struct net *net) { + struct sock *sk; + local_bh_disable(); + sk = icmp_sk(net); + if (unlikely(!spin_trylock(&sk->sk_lock.slock))) { /* This can happen if the output path signals a * dst_link_failure() for an outgoing ICMP packet. */ local_bh_enable(); - return 1; + return NULL; } - return 0; + return sk; } static inline void icmp_xmit_unlock(struct sock *sk) @@ -354,15 +358,17 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb) struct ipcm_cookie ipc; struct rtable *rt = skb->rtable; struct net *net = dev_net(rt->u.dst.dev); - struct sock *sk = icmp_sk(net); - struct inet_sock *inet = inet_sk(sk); + struct sock *sk; + struct inet_sock *inet; __be32 daddr; if (ip_options_echo(&icmp_param->replyopts, skb)) return; - if (icmp_xmit_lock(sk)) + sk = icmp_xmit_lock(net); + if (sk == NULL) return; + inet = inet_sk(sk); icmp_param->data.icmph.checksum = 0; @@ -419,7 +425,6 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info) if (!rt) goto out; net = dev_net(rt->u.dst.dev); - sk = icmp_sk(net); /* * Find the original header. It is expected to be valid, of course. @@ -483,7 +488,8 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info) } } - if (icmp_xmit_lock(sk)) + sk = icmp_xmit_lock(net); + if (sk == NULL) return; /* |