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authorDenis V. Lunev <den@openvz.org>2008-08-23 04:43:33 -0700
committerDavid S. Miller <davem@davemloft.net>2008-08-23 04:43:33 -0700
commitfdc0bde90a689b9145f2b6f271c03f4c99d09667 (patch)
treef29db0a155cee7349f20862d0e1601a5696979df /net/ipv4/icmp.c
parentf6e0b239a2657ea8cb67f0d83d0bfdbfd19a481b (diff)
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.c22
1 files changed, 14 insertions, 8 deletions
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index 860558633b2..55c355e6323 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;
/*