From: Zach Brown Date: Fri, 22 Jun 2007 22:14:46 +0000 (-0700) Subject: SCTP: lock_sock_nested in sctp_sock_migrate X-Git-Tag: v2.6.22-rc7~12^2~2^2 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=5131a184a3458d9ac47d9eba032cf4c4d3295afd;p=linux-2.6-omap-h63xx.git SCTP: lock_sock_nested in sctp_sock_migrate 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: [] sctp_sock_migrate+0x2e3/0x327 [sctp] but task is already holding lock: (sk_lock-AF_INET){--..}, at: [] sctp_accept+0xdf/0x1e3 [sctp] This patch tells lockdep that this locking is safe by using lock_sock_nested(). Signed-off-by: Zach Brown Signed-off-by: Vlad Yasevich --- diff --git a/net/sctp/socket.c b/net/sctp/socket.c index 2fc036699d4..67861a8f00c 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -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 * backlog processing on the old socket and new-packet processing * 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); /* If the association on the newsk is already closed before accept()