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Commit fafc4e1e authored by Hannes Frederic Sowa's avatar Hannes Frederic Sowa Committed by David S. Miller
Browse files

sock: tigthen lockdep checks for sock_owned_by_user 



sock_owned_by_user should not be used without socket lock held. It seems
to be a common practice to check .owned before lock reclassification, so
provide a little help to abstract this check away.

Cc: linux-cifs@vger.kernel.org
Cc: linux-bluetooth@vger.kernel.org
Cc: linux-nfs@vger.kernel.org
Signed-off-by: default avatarHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 18b46810

fs/cifs/connect.c

+2 −2
Original line number Diff line number Diff line
@@ -2918,7 +2918,7 @@ static inline void 
cifs_reclassify_socket4(struct socket *sock)

{

	struct sock *sk = sock->sk;

	BUG_ON(sock_owned_by_user(sk));

	BUG_ON(!sock_allow_reclassification(sk));

	sock_lock_init_class_and_name(sk, "slock-AF_INET-CIFS",

		&cifs_slock_key[0], "sk_lock-AF_INET-CIFS", &cifs_key[0]);

}
@@ -2927,7 +2927,7 @@ static inline void 
cifs_reclassify_socket6(struct socket *sock)

{

	struct sock *sk = sock->sk;

	BUG_ON(sock_owned_by_user(sk));

	BUG_ON(!sock_allow_reclassification(sk));

	sock_lock_init_class_and_name(sk, "slock-AF_INET6-CIFS",

		&cifs_slock_key[1], "sk_lock-AF_INET6-CIFS", &cifs_key[1]);

}

include/net/sock.h

+29 −15
Original line number Diff line number Diff line
@@ -1316,21 +1316,6 @@ static inline void sk_wmem_free_skb(struct sock *sk, struct sk_buff *skb) 
	__kfree_skb(skb);

}



/* Used by processes to "lock" a socket state, so that

 * interrupts and bottom half handlers won't change it

 * from under us. It essentially blocks any incoming

 * packets, so that we won't get any new data or any

 * packets that change the state of the socket.

 *

 * While locked, BH processing will add new packets to

 * the backlog queue.  This queue is processed by the

 * owner of the socket lock right before it is released.

 *

 * Since ~2.3.5 it is also exclusive sleep lock serializing

 * accesses from user process context.

 */

#define sock_owned_by_user(sk)	((sk)->sk_lock.owned)



static inline void sock_release_ownership(struct sock *sk)

{

	if (sk->sk_lock.owned) {
@@ -1403,6 +1388,35 @@ static inline void unlock_sock_fast(struct sock *sk, bool slow) 
		spin_unlock_bh(&sk->sk_lock.slock);

}



/* Used by processes to "lock" a socket state, so that

 * interrupts and bottom half handlers won't change it

 * from under us. It essentially blocks any incoming

 * packets, so that we won't get any new data or any

 * packets that change the state of the socket.

 *

 * While locked, BH processing will add new packets to

 * the backlog queue.  This queue is processed by the

 * owner of the socket lock right before it is released.

 *

 * Since ~2.3.5 it is also exclusive sleep lock serializing

 * accesses from user process context.

 */



static inline bool sock_owned_by_user(const struct sock *sk)

{

#ifdef CONFIG_LOCKDEP

	WARN_ON(!lockdep_sock_is_held(sk));

#endif

	return sk->sk_lock.owned;

}



/* no reclassification while locks are held */

static inline bool sock_allow_reclassification(const struct sock *csk)

{

	struct sock *sk = (struct sock *)csk;



	return !sk->sk_lock.owned && !spin_is_locked(&sk->sk_lock.slock);

}



struct sock *sk_alloc(struct net *net, int family, gfp_t priority,

		      struct proto *prot, int kern);

net/bluetooth/af_bluetooth.c

+1 −1
Original line number Diff line number Diff line
@@ -65,7 +65,7 @@ static const char *const bt_slock_key_strings[BT_MAX_PROTO] = { 
void bt_sock_reclassify_lock(struct sock *sk, int proto)

{

	BUG_ON(!sk);

	BUG_ON(sock_owned_by_user(sk));

	BUG_ON(!sock_allow_reclassification(sk));



	sock_lock_init_class_and_name(sk,

			bt_slock_key_strings[proto], &bt_slock_key[proto],

net/llc/llc_proc.c

+1 −1
Original line number Diff line number Diff line
@@ -195,7 +195,7 @@ static int llc_seq_core_show(struct seq_file *seq, void *v) 
		   timer_pending(&llc->pf_cycle_timer.timer),

		   timer_pending(&llc->rej_sent_timer.timer),

		   timer_pending(&llc->busy_state_timer.timer),

		   !!sk->sk_backlog.tail, !!sock_owned_by_user(sk));

		   !!sk->sk_backlog.tail, !!sk->sk_lock.owned);

out:

	return 0;

}

net/sunrpc/svcsock.c

+1 −2
Original line number Diff line number Diff line
@@ -85,8 +85,7 @@ static void svc_reclassify_socket(struct socket *sock) 
{

	struct sock *sk = sock->sk;



	WARN_ON_ONCE(sock_owned_by_user(sk));

	if (sock_owned_by_user(sk))

	if (WARN_ON_ONCE(!sock_allow_reclassification(sk)))

		return;



	switch (sk->sk_family) {