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-rw-r--r--include/net/sock.h20
-rw-r--r--net/core/sock.c97
2 files changed, 98 insertions, 19 deletions
diff --git a/include/net/sock.h b/include/net/sock.h
index 0969fb6..324b3ea 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -44,6 +44,7 @@
#include <linux/timer.h>
#include <linux/cache.h>
#include <linux/module.h>
+#include <linux/lockdep.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h> /* struct sk_buff */
#include <linux/security.h>
@@ -78,18 +79,17 @@ typedef struct {
spinlock_t slock;
struct sock_iocb *owner;
wait_queue_head_t wq;
+ /*
+ * We express the mutex-alike socket_lock semantics
+ * to the lock validator by explicitly managing
+ * the slock as a lock variant (in addition to
+ * the slock itself):
+ */
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ struct lockdep_map dep_map;
+#endif
} socket_lock_t;
-extern struct lock_class_key af_family_keys[AF_MAX];
-
-#define sock_lock_init(__sk) \
-do { spin_lock_init(&((__sk)->sk_lock.slock)); \
- lockdep_set_class(&(__sk)->sk_lock.slock, \
- af_family_keys + (__sk)->sk_family); \
- (__sk)->sk_lock.owner = NULL; \
- init_waitqueue_head(&((__sk)->sk_lock.wq)); \
-} while(0)
-
struct sock;
struct proto;
diff --git a/net/core/sock.c b/net/core/sock.c
index 0b4d5d2..51fcfbc 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -133,7 +133,42 @@
* Each address family might have different locking rules, so we have
* one slock key per address family:
*/
-struct lock_class_key af_family_keys[AF_MAX];
+static struct lock_class_key af_family_keys[AF_MAX];
+static struct lock_class_key af_family_slock_keys[AF_MAX];
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+/*
+ * Make lock validator output more readable. (we pre-construct these
+ * strings build-time, so that runtime initialization of socket
+ * locks is fast):
+ */
+static const char *af_family_key_strings[AF_MAX+1] = {
+ "sk_lock-AF_UNSPEC", "sk_lock-AF_UNIX" , "sk_lock-AF_INET" ,
+ "sk_lock-AF_AX25" , "sk_lock-AF_IPX" , "sk_lock-AF_APPLETALK",
+ "sk_lock-AF_NETROM", "sk_lock-AF_BRIDGE" , "sk_lock-AF_ATMPVC" ,
+ "sk_lock-AF_X25" , "sk_lock-AF_INET6" , "sk_lock-AF_ROSE" ,
+ "sk_lock-AF_DECnet", "sk_lock-AF_NETBEUI" , "sk_lock-AF_SECURITY" ,
+ "sk_lock-AF_KEY" , "sk_lock-AF_NETLINK" , "sk_lock-AF_PACKET" ,
+ "sk_lock-AF_ASH" , "sk_lock-AF_ECONET" , "sk_lock-AF_ATMSVC" ,
+ "sk_lock-21" , "sk_lock-AF_SNA" , "sk_lock-AF_IRDA" ,
+ "sk_lock-AF_PPPOX" , "sk_lock-AF_WANPIPE" , "sk_lock-AF_LLC" ,
+ "sk_lock-27" , "sk_lock-28" , "sk_lock-29" ,
+ "sk_lock-AF_TIPC" , "sk_lock-AF_BLUETOOTH", "sk_lock-AF_MAX"
+};
+static const char *af_family_slock_key_strings[AF_MAX+1] = {
+ "slock-AF_UNSPEC", "slock-AF_UNIX" , "slock-AF_INET" ,
+ "slock-AF_AX25" , "slock-AF_IPX" , "slock-AF_APPLETALK",
+ "slock-AF_NETROM", "slock-AF_BRIDGE" , "slock-AF_ATMPVC" ,
+ "slock-AF_X25" , "slock-AF_INET6" , "slock-AF_ROSE" ,
+ "slock-AF_DECnet", "slock-AF_NETBEUI" , "slock-AF_SECURITY" ,
+ "slock-AF_KEY" , "slock-AF_NETLINK" , "slock-AF_PACKET" ,
+ "slock-AF_ASH" , "slock-AF_ECONET" , "slock-AF_ATMSVC" ,
+ "slock-21" , "slock-AF_SNA" , "slock-AF_IRDA" ,
+ "slock-AF_PPPOX" , "slock-AF_WANPIPE" , "slock-AF_LLC" ,
+ "slock-27" , "slock-28" , "slock-29" ,
+ "slock-AF_TIPC" , "slock-AF_BLUETOOTH", "slock-AF_MAX"
+};
+#endif
/*
* sk_callback_lock locking rules are per-address-family,
@@ -249,9 +284,16 @@ int sk_receive_skb(struct sock *sk, struct sk_buff *skb)
skb->dev = NULL;
bh_lock_sock(sk);
- if (!sock_owned_by_user(sk))
+ if (!sock_owned_by_user(sk)) {
+ /*
+ * trylock + unlock semantics:
+ */
+ mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);
+
rc = sk->sk_backlog_rcv(sk, skb);
- else
+
+ mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
+ } else
sk_add_backlog(sk, skb);
bh_unlock_sock(sk);
out:
@@ -761,6 +803,33 @@ lenout:
return 0;
}
+/*
+ * Initialize an sk_lock.
+ *
+ * (We also register the sk_lock with the lock validator.)
+ */
+static void inline sock_lock_init(struct sock *sk)
+{
+ spin_lock_init(&sk->sk_lock.slock);
+ sk->sk_lock.owner = NULL;
+ init_waitqueue_head(&sk->sk_lock.wq);
+ /*
+ * Make sure we are not reinitializing a held lock:
+ */
+ debug_check_no_locks_freed((void *)&sk->sk_lock, sizeof(sk->sk_lock));
+
+ /*
+ * Mark both the sk_lock and the sk_lock.slock as a
+ * per-address-family lock class:
+ */
+ lockdep_set_class_and_name(&sk->sk_lock.slock,
+ af_family_slock_keys + sk->sk_family,
+ af_family_slock_key_strings[sk->sk_family]);
+ lockdep_init_map(&sk->sk_lock.dep_map,
+ af_family_key_strings[sk->sk_family],
+ af_family_keys + sk->sk_family);
+}
+
/**
* sk_alloc - All socket objects are allocated here
* @family: protocol family
@@ -1465,24 +1534,34 @@ void sock_init_data(struct socket *sock, struct sock *sk)
void fastcall lock_sock(struct sock *sk)
{
might_sleep();
- spin_lock_bh(&(sk->sk_lock.slock));
+ spin_lock_bh(&sk->sk_lock.slock);
if (sk->sk_lock.owner)
__lock_sock(sk);
sk->sk_lock.owner = (void *)1;
- spin_unlock_bh(&(sk->sk_lock.slock));
+ spin_unlock(&sk->sk_lock.slock);
+ /*
+ * The sk_lock has mutex_lock() semantics here:
+ */
+ mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_);
+ local_bh_enable();
}
EXPORT_SYMBOL(lock_sock);
void fastcall release_sock(struct sock *sk)
{
- spin_lock_bh(&(sk->sk_lock.slock));
+ /*
+ * The sk_lock has mutex_unlock() semantics:
+ */
+ mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
+
+ spin_lock_bh(&sk->sk_lock.slock);
if (sk->sk_backlog.tail)
__release_sock(sk);
sk->sk_lock.owner = NULL;
- if (waitqueue_active(&(sk->sk_lock.wq)))
- wake_up(&(sk->sk_lock.wq));
- spin_unlock_bh(&(sk->sk_lock.slock));
+ if (waitqueue_active(&sk->sk_lock.wq))
+ wake_up(&sk->sk_lock.wq);
+ spin_unlock_bh(&sk->sk_lock.slock);
}
EXPORT_SYMBOL(release_sock);
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