---

yaml
---
r: 86709
b: refs/heads/master
c: a6c0e1f
h: refs/heads/master
i:
  86707: 3ec53ec
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 966ea8c4b74aa6fde2d58c50a904619fd849ae93
+refs/heads/master: a6c0e1f71d37b89c883d636eca48a017c055c8c4

trunk/kernel/power/process.c

@@ -75,22 +75,15 @@ void refrigerator(void)
 	__set_current_state(save);
 }
 
-static void fake_signal_wake_up(struct task_struct *p, int resume)
+static void fake_signal_wake_up(struct task_struct *p)
 {
 	unsigned long flags;
 
 	spin_lock_irqsave(&p->sighand->siglock, flags);
-	signal_wake_up(p, resume);
+	signal_wake_up(p, 0);
 	spin_unlock_irqrestore(&p->sighand->siglock, flags);
 }
 
-static void send_fake_signal(struct task_struct *p)
-{
-	if (task_is_stopped(p))
-		force_sig_specific(SIGSTOP, p);
-	fake_signal_wake_up(p, task_is_stopped(p));
-}
-
 static int has_mm(struct task_struct *p)
 {
 	return (p->mm && !(p->flags & PF_BORROWED_MM));
@@ -121,7 +114,7 @@ static int freeze_task(struct task_struct *p, int with_mm_only)
 	if (freezing(p)) {
 		if (has_mm(p)) {
 			if (!signal_pending(p))
-				fake_signal_wake_up(p, 0);
+				fake_signal_wake_up(p);
 		} else {
 			if (with_mm_only)
 				ret = 0;
@@ -135,7 +128,7 @@ static int freeze_task(struct task_struct *p, int with_mm_only)
 		} else {
 			if (has_mm(p)) {
 				set_freeze_flag(p);
-				send_fake_signal(p);
+				fake_signal_wake_up(p);
 			} else {
 				if (with_mm_only) {
 					ret = 0;
@@ -182,15 +175,17 @@ static int try_to_freeze_tasks(int freeze_user_space)
 			if (frozen(p) || !freezeable(p))
 				continue;
 
-			if (task_is_traced(p) && frozen(p->parent)) {
-				cancel_freezing(p);
-				continue;
-			}
-
 			if (!freeze_task(p, freeze_user_space))
 				continue;
 
-			if (!freezer_should_skip(p))
+			/*
+			 * Now that we've done set_freeze_flag, don't
+			 * perturb a task in TASK_STOPPED or TASK_TRACED.
+			 * It is "frozen enough".  If the task does wake
+			 * up, it will immediately call try_to_freeze.
+			 */
+			if (!task_is_stopped_or_traced(p) &&
+			    !freezer_should_skip(p))
 				todo++;
 		} while_each_thread(g, p);
 		read_unlock(&tasklist_lock);

trunk/kernel/signal.c

@@ -1623,7 +1623,6 @@ static void ptrace_stop(int exit_code, int clear_code, siginfo_t *info)
 	/* Let the debugger run.  */
 	__set_current_state(TASK_TRACED);
 	spin_unlock_irq(&current->sighand->siglock);
-	try_to_freeze();
 	read_lock(&tasklist_lock);
 	if (!unlikely(killed) && may_ptrace_stop()) {
 		do_notify_parent_cldstop(current, CLD_TRAPPED);
@@ -1640,6 +1639,13 @@ static void ptrace_stop(int exit_code, int clear_code, siginfo_t *info)
 		read_unlock(&tasklist_lock);
 	}
 
+	/*
+	 * While in TASK_TRACED, we were considered "frozen enough".
+	 * Now that we woke up, it's crucial if we're supposed to be
+	 * frozen that we freeze now before running anything substantial.
+	 */
+	try_to_freeze();
+
 	/*
 	 * We are back.  Now reacquire the siglock before touching
 	 * last_siginfo, so that we are sure to have synchronized with
@@ -1757,9 +1763,15 @@ int get_signal_to_deliver(siginfo_t *info, struct k_sigaction *return_ka,
 	sigset_t *mask = &current->blocked;
 	int signr = 0;
 
+relock:
+	/*
+	 * We'll jump back here after any time we were stopped in TASK_STOPPED.
+	 * While in TASK_STOPPED, we were considered "frozen enough".
+	 * Now that we woke up, it's crucial if we're supposed to be
+	 * frozen that we freeze now before running anything substantial.
+	 */
 	try_to_freeze();
 
-relock:
 	spin_lock_irq(&current->sighand->siglock);
 	for (;;) {
 		struct k_sigaction *ka;