forge/linux-pinenote
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

SCTP: lock_sock_nested in sctp_sock_migrate

Browse source 
sctp_sock_migrate() grabs the socket lock on a newly allocated socket while
holding the socket lock on an old socket.  lockdep worries that this might
be a recursive lock attempt.

 task/3026 is trying to acquire lock:
  (sk_lock-AF_INET){--..}, at: [<ffffffff88105b8c>] sctp_sock_migrate+0x2e3/0x327 [sctp]
 but task is already holding lock:
  (sk_lock-AF_INET){--..}, at: [<ffffffff8810891f>] sctp_accept+0xdf/0x1e3 [sctp]

This patch tells lockdep that this locking is safe by using
lock_sock_nested().

Signed-off-by: Zach Brown <zach.brown@oracle.com>
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
This commit is contained in:
Zach Brown 2007-06-22 15:14:46 -07:00 • committed by Vlad Yasevich
commit 5131a184a3
1 changed files with 4 additions and 1 deletions
Download patch file Download diff file Expand all files Collapse all files

5
net/sctp/socket.c
View file

@ -6123,8 +6123,11 @@ static void sctp_sock_migrate(struct sock *oldsk, struct sock *newsk,
* queued to the backlog. This prevents a potential race between * queued to the backlog. This prevents a potential race between
* backlog processing on the old socket and new-packet processing * backlog processing on the old socket and new-packet processing
* on the new socket. * on the new socket.
*
* The caller has just allocated newsk so we can guarantee that other
* paths won't try to lock it and then oldsk.
*/ */
sctp_lock_sock(newsk); lock_sock_nested(newsk, SINGLE_DEPTH_NESTING);
sctp_assoc_migrate(assoc, newsk); sctp_assoc_migrate(assoc, newsk);
/* If the association on the newsk is already closed before accept() /* If the association on the newsk is already closed before accept()