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authorIngo Molnar <mingo@elte.hu>2006-07-03 00:25:12 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-07-03 15:27:07 -0700
commita09785a2414afb261d9f719d544742af4300df22 (patch)
treea9fcbd82e9610cb77e7a2e1338ab901876dbcea8
parentda21f24dd73954c2ed0cd39a698e2c9916c05d71 (diff)
downloadlinux-a09785a2414afb261d9f719d544742af4300df22.tar.bz2
[PATCH] lockdep: annotate af_unix locking
Teach special (recursive) locking code to the lock validator. Also splits af_unix's sk_receive_queue.lock class from the other networking skb-queue locks. Has no effect on non-lockdep kernels. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--include/net/af_unix.h3
-rw-r--r--net/unix/af_unix.c12
2 files changed, 14 insertions, 1 deletions
diff --git a/include/net/af_unix.h b/include/net/af_unix.h
index 5ba72d95280c..2fec827c8801 100644
--- a/include/net/af_unix.h
+++ b/include/net/af_unix.h
@@ -67,6 +67,9 @@ struct unix_skb_parms {
#define unix_state_rlock(s) spin_lock(&unix_sk(s)->lock)
#define unix_state_runlock(s) spin_unlock(&unix_sk(s)->lock)
#define unix_state_wlock(s) spin_lock(&unix_sk(s)->lock)
+#define unix_state_wlock_nested(s) \
+ spin_lock_nested(&unix_sk(s)->lock, \
+ SINGLE_DEPTH_NESTING)
#define unix_state_wunlock(s) spin_unlock(&unix_sk(s)->lock)
#ifdef __KERNEL__
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index aca650109425..e9a287bc3142 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -565,6 +565,14 @@ static struct proto unix_proto = {
.obj_size = sizeof(struct unix_sock),
};
+/*
+ * AF_UNIX sockets do not interact with hardware, hence they
+ * dont trigger interrupts - so it's safe for them to have
+ * bh-unsafe locking for their sk_receive_queue.lock. Split off
+ * this special lock-class by reinitializing the spinlock key:
+ */
+static struct lock_class_key af_unix_sk_receive_queue_lock_key;
+
static struct sock * unix_create1(struct socket *sock)
{
struct sock *sk = NULL;
@@ -580,6 +588,8 @@ static struct sock * unix_create1(struct socket *sock)
atomic_inc(&unix_nr_socks);
sock_init_data(sock,sk);
+ lockdep_set_class(&sk->sk_receive_queue.lock,
+ &af_unix_sk_receive_queue_lock_key);
sk->sk_write_space = unix_write_space;
sk->sk_max_ack_backlog = sysctl_unix_max_dgram_qlen;
@@ -1045,7 +1055,7 @@ restart:
goto out_unlock;
}
- unix_state_wlock(sk);
+ unix_state_wlock_nested(sk);
if (sk->sk_state != st) {
unix_state_wunlock(sk);