diff --git a/net/unix/garbage.c b/net/unix/garbage.c index 12e2ddaf887f..d45d5366115a 100644 --- a/net/unix/garbage.c +++ b/net/unix/garbage.c @@ -192,8 +192,11 @@ void wait_for_unix_gc(void) { /* If number of inflight sockets is insane, * force a garbage collect right now. + * Paired with the WRITE_ONCE() in unix_inflight(), + * unix_notinflight() and gc_in_progress(). */ - if (unix_tot_inflight > UNIX_INFLIGHT_TRIGGER_GC && !gc_in_progress) + if (READ_ONCE(unix_tot_inflight) > UNIX_INFLIGHT_TRIGGER_GC && + !READ_ONCE(gc_in_progress)) unix_gc(); wait_event(unix_gc_wait, gc_in_progress == false); } @@ -213,7 +216,9 @@ void unix_gc(void) if (gc_in_progress) goto out; - gc_in_progress = true; + /* Paired with READ_ONCE() in wait_for_unix_gc(). */ + WRITE_ONCE(gc_in_progress, true); + /* First, select candidates for garbage collection. Only * in-flight sockets are considered, and from those only ones * which don't have any external reference. @@ -299,7 +304,10 @@ void unix_gc(void) /* All candidates should have been detached by now. */ BUG_ON(!list_empty(&gc_candidates)); - gc_in_progress = false; + + /* Paired with READ_ONCE() in wait_for_unix_gc(). */ + WRITE_ONCE(gc_in_progress, false); + wake_up(&unix_gc_wait); out: diff --git a/net/unix/scm.c b/net/unix/scm.c index 8c40f2b32392..ce700b22ecce 100644 --- a/net/unix/scm.c +++ b/net/unix/scm.c @@ -59,7 +59,8 @@ void unix_inflight(struct user_struct *user, struct file *fp) } else { BUG_ON(list_empty(&u->link)); } - unix_tot_inflight++; + /* Paired with READ_ONCE() in wait_for_unix_gc() */ + WRITE_ONCE(unix_tot_inflight, unix_tot_inflight + 1); } user->unix_inflight++; spin_unlock(&unix_gc_lock); @@ -79,7 +80,8 @@ void unix_notinflight(struct user_struct *user, struct file *fp) if (atomic_long_dec_and_test(&u->inflight)) list_del_init(&u->link); - unix_tot_inflight--; + /* Paired with READ_ONCE() in wait_for_unix_gc() */ + WRITE_ONCE(unix_tot_inflight, unix_tot_inflight - 1); } user->unix_inflight--; spin_unlock(&unix_gc_lock);