If we set TIF_SIGPENDING for SIGCONT, we have to wake up any sleeping

tasks (even if we don't otherwise need to wake anything up), since
otherwise later signals would see that signals are already pending and
wouldn't cause wakeups.

kernel/signal.c

@@ -619,6 +619,7 @@ static void handle_stop_signal(int sig, struct task_struct *p)
 		rm_from_queue(SIG_KERNEL_STOP_MASK, &p->signal->shared_pending);
 		t = p;
 		do {
+			unsigned int state;
 			rm_from_queue(SIG_KERNEL_STOP_MASK, &t->pending);
 			
 			/*
@@ -635,9 +636,12 @@ static void handle_stop_signal(int sig, struct task_struct *p)
 			 * Wake up the stopped thread _after_ setting
 			 * TIF_SIGPENDING
 			 */
-			if (!sigismember(&t->blocked, SIGCONT))
+			state = TASK_STOPPED;
+			if (!sigismember(&t->blocked, SIGCONT)) {
 				set_tsk_thread_flag(t, TIF_SIGPENDING);
-			wake_up_state(t, TASK_STOPPED);
+				state |= TASK_INTERRUPTIBLE;
+			}
+			wake_up_state(t, state);
 
 			t = next_thread(t);
 		} while (t != p);