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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: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
hifive-unleashed-5.1
Hannes Frederic Sowa 2016-04-08 15:11:27 +02:00 committed by David S. Miller
parent 18b46810eb
commit fafc4e1ea1
6 changed files with 35 additions and 23 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
fs/cifs/connect.c
View File

@ -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]);
}

44
include/net/sock.h
View File

@ -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);

2
net/bluetooth/af_bluetooth.c
View File

@ -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],

2
net/llc/llc_proc.c
View File

@ -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;
}

3
net/sunrpc/svcsock.c
View File

@ -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) {

3
net/sunrpc/xprtsock.c
View File

@ -1880,8 +1880,7 @@ static inline void xs_reclassify_socket6(struct socket *sock)
static inline void xs_reclassify_socket(int family, struct socket *sock)
{
WARN_ON_ONCE(sock_owned_by_user(sock->sk));
if (sock_owned_by_user(sock->sk))
if (WARN_ON_ONCE(!sock_allow_reclassification(sock->sk)))
return;
switch (family) {