Wake up a stopped task _after_ having marked the SIGCONT pending,

so that there isn't any window for running before the signal
handler has been invoced.

diff --git a/kernel/signal.c b/kernel/signal.c
index 63c16ac1a9fa92824abd67b5bc88bf4089ed39e6..a4d6618f77d06785f5cde986c28c4dfb0a722c44 100644 (file)
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -620,7 +620,6 @@ static void handle_stop_signal(int sig, struct task_struct *p)
                t = p;
                do {
                        rm_from_queue(SIG_KERNEL_STOP_MASK, &t->pending);
-                       wake_up_state(t, TASK_STOPPED);
                        
                        /*
                         * If there is a handler for SIGCONT, we must make
@@ -632,9 +631,13 @@ static void handle_stop_signal(int sig, struct task_struct *p)
                         * flag set, the thread will pause and acquire the
                         * siglock that we hold now and until we've queued
                         * the pending signal. 
+                        *
+                        * Wake up the stopped thread _after_ setting
+                        * TIF_SIGPENDING
                         */
                        if (!sigismember(&t->blocked, SIGCONT))
                                set_tsk_thread_flag(t, TIF_SIGPENDING);
+                       wake_up_state(t, TASK_STOPPED);
 
                        t = next_thread(t);
                } while (t != p);