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authorHerbert Xu <herbert@gondor.apana.org.au>2008-12-29 23:04:08 -0800
committerDavid S. Miller <davem@davemloft.net>2008-12-29 23:04:08 -0800
commiteb4dea5853046727bfbb579f0c9a8cae7369f7c6 (patch)
tree79e18d6284494ab63a890885b0eecce9431a9597 /net
parent0f23174aa8c1aa7a2a6050a72a60d290ef9ee578 (diff)
downloadlinux-2.6.34-ux500-eb4dea5853046727bfbb579f0c9a8cae7369f7c6.tar.gz
net: Fix percpu counters deadlock
When we converted the protocol atomic counters such as the orphan count and the total socket count deadlocks were introduced due to the mismatch in BH status of the spots that used the percpu counter operations. Based on the diagnosis and patch by Peter Zijlstra, this patch fixes these issues by disabling BH where we may be in process context. Reported-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Tested-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/dccp/proto.c3
-rw-r--r--net/ipv4/inet_connection_sock.c4
-rw-r--r--net/ipv4/proc.c13
-rw-r--r--net/ipv4/tcp.c3
-rw-r--r--net/ipv4/tcp_ipv4.c3
-rw-r--r--net/ipv6/tcp_ipv6.c3
6 files changed, 21 insertions, 8 deletions
diff --git a/net/dccp/proto.c b/net/dccp/proto.c
index d5c2bacb713..1747ccae8e8 100644
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -964,7 +964,6 @@ adjudge_to_death:
state = sk->sk_state;
sock_hold(sk);
sock_orphan(sk);
- percpu_counter_inc(sk->sk_prot->orphan_count);
/*
* It is the last release_sock in its life. It will remove backlog.
@@ -978,6 +977,8 @@ adjudge_to_death:
bh_lock_sock(sk);
WARN_ON(sock_owned_by_user(sk));
+ percpu_counter_inc(sk->sk_prot->orphan_count);
+
/* Have we already been destroyed by a softirq or backlog? */
if (state != DCCP_CLOSED && sk->sk_state == DCCP_CLOSED)
goto out;
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index c7cda1ca8e6..f26ab38680d 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -633,8 +633,6 @@ void inet_csk_listen_stop(struct sock *sk)
acc_req = req->dl_next;
- percpu_counter_inc(sk->sk_prot->orphan_count);
-
local_bh_disable();
bh_lock_sock(child);
WARN_ON(sock_owned_by_user(child));
@@ -644,6 +642,8 @@ void inet_csk_listen_stop(struct sock *sk)
sock_orphan(child);
+ percpu_counter_inc(sk->sk_prot->orphan_count);
+
inet_csk_destroy_sock(child);
bh_unlock_sock(child);
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index 614958b7c27..eb62e58bff7 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -38,6 +38,7 @@
#include <net/tcp.h>
#include <net/udp.h>
#include <net/udplite.h>
+#include <linux/bottom_half.h>
#include <linux/inetdevice.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
@@ -50,13 +51,17 @@
static int sockstat_seq_show(struct seq_file *seq, void *v)
{
struct net *net = seq->private;
+ int orphans, sockets;
+
+ local_bh_disable();
+ orphans = percpu_counter_sum_positive(&tcp_orphan_count),
+ sockets = percpu_counter_sum_positive(&tcp_sockets_allocated),
+ local_bh_enable();
socket_seq_show(seq);
seq_printf(seq, "TCP: inuse %d orphan %d tw %d alloc %d mem %d\n",
- sock_prot_inuse_get(net, &tcp_prot),
- (int)percpu_counter_sum_positive(&tcp_orphan_count),
- tcp_death_row.tw_count,
- (int)percpu_counter_sum_positive(&tcp_sockets_allocated),
+ sock_prot_inuse_get(net, &tcp_prot), orphans,
+ tcp_death_row.tw_count, sockets,
atomic_read(&tcp_memory_allocated));
seq_printf(seq, "UDP: inuse %d mem %d\n",
sock_prot_inuse_get(net, &udp_prot),
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 1f3d52946b3..f28acf11fc6 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1836,7 +1836,6 @@ adjudge_to_death:
state = sk->sk_state;
sock_hold(sk);
sock_orphan(sk);
- percpu_counter_inc(sk->sk_prot->orphan_count);
/* It is the last release_sock in its life. It will remove backlog. */
release_sock(sk);
@@ -1849,6 +1848,8 @@ adjudge_to_death:
bh_lock_sock(sk);
WARN_ON(sock_owned_by_user(sk));
+ percpu_counter_inc(sk->sk_prot->orphan_count);
+
/* Have we already been destroyed by a softirq or backlog? */
if (state != TCP_CLOSE && sk->sk_state == TCP_CLOSE)
goto out;
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 10172487921..9d839fa9331 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -51,6 +51,7 @@
*/
+#include <linux/bottom_half.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/module.h>
@@ -1797,7 +1798,9 @@ static int tcp_v4_init_sock(struct sock *sk)
sk->sk_sndbuf = sysctl_tcp_wmem[1];
sk->sk_rcvbuf = sysctl_tcp_rmem[1];
+ local_bh_disable();
percpu_counter_inc(&tcp_sockets_allocated);
+ local_bh_enable();
return 0;
}
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 8702b06cb60..e8b8337a831 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -23,6 +23,7 @@
* 2 of the License, or (at your option) any later version.
*/
+#include <linux/bottom_half.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/types.h>
@@ -1830,7 +1831,9 @@ static int tcp_v6_init_sock(struct sock *sk)
sk->sk_sndbuf = sysctl_tcp_wmem[1];
sk->sk_rcvbuf = sysctl_tcp_rmem[1];
+ local_bh_disable();
percpu_counter_inc(&tcp_sockets_allocated);
+ local_bh_enable();
return 0;
}