The patch titled lockdep: annotate sk_lock nesting in AF_BLUETOOTH has been added to the -mm tree. Its filename is lockdep-annotate-sk_lock-nesting-in-af_bluetooth-v2.patch See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find out what to do about this ------------------------------------------------------ Subject: lockdep: annotate sk_lock nesting in AF_BLUETOOTH From: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> ============================================= [ INFO: possible recursive locking detected ] 2.6.18-1.2726.fc6 #1 --------------------------------------------- hidd/2271 is trying to acquire lock: (sk_lock-AF_BLUETOOTH){--..}, at: [<f8d16241>] bt_accept_dequeue+0x26/0xc6 [bluetooth] but task is already holding lock: (sk_lock-AF_BLUETOOTH){--..}, at: [<f8bce088>] l2cap_sock_accept+0x41/0x11e [l2cap] other info that might help us debug this: 1 lock held by hidd/2271: #0: (sk_lock-AF_BLUETOOTH){--..}, at: [<f8bce088>] l2cap_sock_accept+0x41/0x11e [l2cap] stack backtrace: [<c04051ed>] show_trace_log_lvl+0x58/0x16a [<c04057fa>] show_trace+0xd/0x10 [<c0405913>] dump_stack+0x19/0x1b [<c043b7dc>] __lock_acquire+0x6ea/0x90d [<c043bf70>] lock_acquire+0x4b/0x6b [<c05b203b>] lock_sock+0xac/0xbc [<f8d16241>] bt_accept_dequeue+0x26/0xc6 [bluetooth] [<f8bce129>] l2cap_sock_accept+0xe2/0x11e [l2cap] [<c05b142e>] sys_accept+0xd8/0x179 [<c05b1576>] sys_socketcall+0xa7/0x186 [<c0403fb7>] syscall_call+0x7/0xb classical case of nesting; bt_accept_dequeue() locks the children of the object locked by l2cap_sock_accept(). Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> Acked-by: Marcel Holtmann <marcel@xxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxx> --- include/net/sock.h | 8 +++++++- net/bluetooth/l2cap.c | 4 ++-- net/core/sock.c | 6 +++--- 3 files changed, 12 insertions(+), 6 deletions(-) diff -puN include/net/sock.h~lockdep-annotate-sk_lock-nesting-in-af_bluetooth-v2 include/net/sock.h --- a/include/net/sock.h~lockdep-annotate-sk_lock-nesting-in-af_bluetooth-v2 +++ a/include/net/sock.h @@ -745,7 +745,13 @@ static inline int sk_stream_wmem_schedul */ #define sock_owned_by_user(sk) ((sk)->sk_lock.owner) -extern void FASTCALL(lock_sock(struct sock *sk)); +extern void FASTCALL(lock_sock_nested(struct sock *sk, int subclass)); + +static inline void lock_sock(struct sock *sk) +{ + lock_sock_nested(sk, 0); +} + extern void FASTCALL(release_sock(struct sock *sk)); /* BH context may only use the following locking interface. */ diff -puN net/bluetooth/l2cap.c~lockdep-annotate-sk_lock-nesting-in-af_bluetooth-v2 net/bluetooth/l2cap.c --- a/net/bluetooth/l2cap.c~lockdep-annotate-sk_lock-nesting-in-af_bluetooth-v2 +++ a/net/bluetooth/l2cap.c @@ -770,7 +770,7 @@ static int l2cap_sock_accept(struct sock long timeo; int err = 0; - lock_sock(sk); + lock_sock_nested(sk, SINGLE_DEPTH_NESTING); if (sk->sk_state != BT_LISTEN) { err = -EBADFD; @@ -792,7 +792,7 @@ static int l2cap_sock_accept(struct sock release_sock(sk); timeo = schedule_timeout(timeo); - lock_sock(sk); + lock_sock_nested(sk, SINGLE_DEPTH_NESTING); if (sk->sk_state != BT_LISTEN) { err = -EBADFD; diff -puN net/core/sock.c~lockdep-annotate-sk_lock-nesting-in-af_bluetooth-v2 net/core/sock.c --- a/net/core/sock.c~lockdep-annotate-sk_lock-nesting-in-af_bluetooth-v2 +++ a/net/core/sock.c @@ -1527,7 +1527,7 @@ void sock_init_data(struct socket *sock, atomic_set(&sk->sk_refcnt, 1); } -void fastcall lock_sock(struct sock *sk) +void fastcall lock_sock_nested(struct sock *sk, int subclass) { might_sleep(); spin_lock_bh(&sk->sk_lock.slock); @@ -1538,11 +1538,11 @@ void fastcall lock_sock(struct sock *sk) /* * The sk_lock has mutex_lock() semantics here: */ - mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_); + mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_); local_bh_enable(); } -EXPORT_SYMBOL(lock_sock); +EXPORT_SYMBOL(lock_sock_nested); void fastcall release_sock(struct sock *sk) { _ Patches currently in -mm which might be from a.p.zijlstra@xxxxxxxxx are bonding-lockdep-annotation.patch lockdep-annotate-sk_lock-nesting-in-af_bluetooth-v2.patch grab-swap-token-reordered.patch new-scheme-to-preempt-swap-token.patch new-scheme-to-preempt-swap-token-tidy.patch lockdep-annotate-nfs-nfsd-in-kernel-sockets.patch lockdep-annotate-nfs-nfsd-in-kernel-sockets-tidy.patch lockdep-fix-ide-proc-interaction.patch tty-signal-tty-locking.patch tty-signal-tty-locking-3270-fix.patch do_task_stat-dont-take-tty_mutex.patch do_acct_process-dont-take-tty_mutex.patch sys_unshare-remove-a-broken-clone_sighand-code.patch remove-the-old-bd_mutex-lockdep-annotation.patch new-bd_mutex-lockdep-annotation.patch remove-lock_key-approach-to-managing-nested-bd_mutex-locks.patch simplify-some-aspects-of-bd_mutex-nesting.patch use-mutex_lock_nested-for-bd_mutex-to-avoid-lockdep-warning.patch avoid-lockdep-warning-in-md.patch lockdep-annotate-nfsd4-recover-code.patch - To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html