diff options
| author | Satyam Sharma <ssatyam@cse.iitk.ac.in> | 2007-06-06 23:02:16 -0700 |
|---|---|---|
| committer | Chris Wright <chrisw@sous-sol.org> | 2007-06-11 11:36:54 -0700 |
| commit | d951c856912acfbb85eb33f59230c3019ef5dd55 (patch) | |
| tree | 504bca3dfe564fd37ab772dfc52e0d675bef2e5a | |
| parent | 02a074766a0a8d1afd26f476b73422c08e34cbc8 (diff) | |
[PATCH] BLUETOOTH: Fix locking in hci_sock_dev_event().
We presently use lock_sock() to acquire a lock on a socket in
hci_sock_dev_event(), but this goes BUG because lock_sock()
can sleep and we're already holding a read-write spinlock at
that point. So, we must use the non-sleeping BH version,
bh_lock_sock().
However, hci_sock_dev_event() is called from user context and
hence using simply bh_lock_sock() will deadlock against a
concurrent softirq that tries to acquire a lock on the same
socket. Hence, disabling BH's before acquiring the socket lock
and enable them afterwards, is the proper solution to fix
socket locking in hci_sock_dev_event().
Signed-off-by: Satyam Sharma <ssatyam@cse.iitk.ac.in>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | net/bluetooth/hci_sock.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/net/bluetooth/hci_sock.c b/net/bluetooth/hci_sock.c index 71f5cfbbebb8..2f6e1ea6a5cc 100644 --- a/net/bluetooth/hci_sock.c +++ b/net/bluetooth/hci_sock.c @@ -656,7 +656,8 @@ static int hci_sock_dev_event(struct notifier_block *this, unsigned long event, /* Detach sockets from device */ read_lock(&hci_sk_list.lock); sk_for_each(sk, node, &hci_sk_list.head) { - lock_sock(sk); + local_bh_disable(); + bh_lock_sock_nested(sk); if (hci_pi(sk)->hdev == hdev) { hci_pi(sk)->hdev = NULL; sk->sk_err = EPIPE; @@ -665,7 +666,8 @@ static int hci_sock_dev_event(struct notifier_block *this, unsigned long event, hci_dev_put(hdev); } - release_sock(sk); + bh_unlock_sock(sk); + local_bh_enable(); } read_unlock(&hci_sk_list.lock); } |