2 files changed, 12 insertions, 3 deletions

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 5aaf23e43f1d..92f52abd3515 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -1351,6 +1351,7 @@ static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock,
 
         if (NULL == siocb->scm)
                 siocb->scm = &tmp_scm;
+        wait_for_unix_gc();
         err = scm_send(sock, msg, siocb->scm);
         if (err < 0)
                 return err;
@@ -1501,6 +1502,7 @@ static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
 
         if (NULL == siocb->scm)
                 siocb->scm = &tmp_scm;
+        wait_for_unix_gc();
         err = scm_send(sock, msg, siocb->scm);
         if (err < 0)
                 return err;
diff --git a/net/unix/garbage.c b/net/unix/garbage.c
index 5a0061d6b9bc..19c17e4a0c8b 100644
--- a/net/unix/garbage.c
+++ b/net/unix/garbage.c
@@ -80,6 +80,7 @@
 #include <linux/file.h>
 #include <linux/proc_fs.h>
 #include <linux/mutex.h>
+#include <linux/wait.h>
 
 #include <net/sock.h>
 #include <net/af_unix.h>
@@ -91,6 +92,7 @@
 static LIST_HEAD(gc_inflight_list);
 static LIST_HEAD(gc_candidates);
 static DEFINE_SPINLOCK(unix_gc_lock);
+static DECLARE_WAIT_QUEUE_HEAD(unix_gc_wait);
 
 unsigned int unix_tot_inflight;
 
@@ -266,12 +268,16 @@ static void inc_inflight_move_tail(struct unix_sock *u)
                 list_move_tail(&u->link, &gc_candidates);
 }
 
-/* The external entry point: unix_gc() */
+static bool gc_in_progress = false;
 
-void unix_gc(void)
+void wait_for_unix_gc(void)
 {
-        static bool gc_in_progress = false;
+        wait_event(unix_gc_wait, gc_in_progress == false);
+}
 
+/* The external entry point: unix_gc() */
+void unix_gc(void)
+{
         struct unix_sock *u;
         struct unix_sock *next;
         struct sk_buff_head hitlist;
@@ -376,6 +382,7 @@ void unix_gc(void)
         /* All candidates should have been detached by now. */
         BUG_ON(!list_empty(&gc_candidates));
         gc_in_progress = false;
+        wake_up(&unix_gc_wait);
 
  out:
         spin_unlock(&unix_gc_lock);