diff options
| -rw-r--r-- | include/net/af_unix.h | 1 | ||||
| -rw-r--r-- | net/unix/af_unix.c | 2 | ||||
| -rw-r--r-- | net/unix/garbage.c | 20 |
3 files changed, 18 insertions, 5 deletions
diff --git a/include/net/af_unix.h b/include/net/af_unix.h index 7311b77edfc7..872ff2a50372 100644 --- a/include/net/af_unix.h +++ b/include/net/af_unix.h @@ -67,6 +67,7 @@ struct unix_skb_parms { struct scm_stat { atomic_t nr_fds; + unsigned long nr_unix_fds; }; #define UNIXCB(skb) (*(struct unix_skb_parms *)&((skb)->cb)) diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index 142d210b5b03..ed16d5f66df8 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -1719,12 +1719,12 @@ static int unix_accept(struct socket *sock, struct socket *newsock, int flags, } tsk = skb->sk; - unix_update_edges(unix_sk(tsk)); skb_free_datagram(sk, skb); wake_up_interruptible(&unix_sk(sk)->peer_wait); /* attach accepted sock to socket */ unix_state_lock(tsk); + unix_update_edges(unix_sk(tsk)); newsock->state = SS_CONNECTED; unix_sock_inherit_flags(sock, newsock); sock_graft(tsk, newsock); diff --git a/net/unix/garbage.c b/net/unix/garbage.c index 12a4ec27e0d4..95240a59808f 100644 --- a/net/unix/garbage.c +++ b/net/unix/garbage.c @@ -209,6 +209,7 @@ void unix_add_edges(struct scm_fp_list *fpl, struct unix_sock *receiver) unix_add_edge(fpl, edge); } while (i < fpl->count_unix); + receiver->scm_stat.nr_unix_fds += fpl->count_unix; WRITE_ONCE(unix_tot_inflight, unix_tot_inflight + fpl->count_unix); out: WRITE_ONCE(fpl->user->unix_inflight, fpl->user->unix_inflight + fpl->count); @@ -222,6 +223,7 @@ out: void unix_del_edges(struct scm_fp_list *fpl) { + struct unix_sock *receiver; int i = 0; spin_lock(&unix_gc_lock); @@ -235,6 +237,8 @@ void unix_del_edges(struct scm_fp_list *fpl) unix_del_edge(fpl, edge); } while (i < fpl->count_unix); + receiver = fpl->edges[0].successor; + receiver->scm_stat.nr_unix_fds -= fpl->count_unix; WRITE_ONCE(unix_tot_inflight, unix_tot_inflight - fpl->count_unix); out: WRITE_ONCE(fpl->user->unix_inflight, fpl->user->unix_inflight - fpl->count); @@ -246,10 +250,18 @@ out: void unix_update_edges(struct unix_sock *receiver) { - spin_lock(&unix_gc_lock); - unix_update_graph(unix_sk(receiver->listener)->vertex); - receiver->listener = NULL; - spin_unlock(&unix_gc_lock); + /* nr_unix_fds is only updated under unix_state_lock(). + * If it's 0 here, the embryo socket is not part of the + * inflight graph, and GC will not see it, so no lock needed. + */ + if (!receiver->scm_stat.nr_unix_fds) { + receiver->listener = NULL; + } else { + spin_lock(&unix_gc_lock); + unix_update_graph(unix_sk(receiver->listener)->vertex); + receiver->listener = NULL; + spin_unlock(&unix_gc_lock); + } } int unix_prepare_fpl(struct scm_fp_list *fpl) |