Fixed a nasty spinlock issue with wake_up_all that didn't get caught.

conts/test/main.c

@@ -36,6 +36,7 @@ int exit_test(void)
 
 	// l4_thread_switch(0);
 
+#if 0
 	/* Kill it */
 	printf("Killing Thread (%d).\n", ids.tid);
 	if ((ret = l4_thread_control(THREAD_DESTROY, &ids)) < 0)
@@ -43,7 +44,7 @@ int exit_test(void)
 	else
 		printf("Success: Killed Thread (%d)\n", ids.tid);
 
-	return 0;
+#endif
 
 #if 0
 	/* Wait on it */
@@ -53,9 +54,9 @@ int exit_test(void)
 	else
 		printf("Error. Wait on (%d) failed. err = %d\n",
 		       ids.tid, ret);
-	return 0;
 #endif
 
+	return 0;
 out_err:
 	BUG();
 }
@@ -70,7 +71,7 @@ int main(void)
 	exit_test();
 
 	/* Now quit to demo self-paging quit */
-	//l4_exit(0);
+	l4_exit(0);
 
 	/* Now quit by null pointer */
 	//	*((int *)0) = 5;

include/l4/lib/wait.h

@@ -59,7 +59,7 @@ do {								\
 		task_set_wqh(current, wqh, &wq);		\
 		(wqh)->sleepers++;				\
 		list_insert_tail(&wq.task_list, &(wqh)->task_list);\
-		/* printk("(%d) waiting...\n", current->tid);*/	\
+		/* printk("(%d) waiting...\n", current->tid); */ \
 		sched_prepare_sleep();				\
 		spin_unlock(&(wqh)->slock);			\
 		schedule();					\

src/api/thread.c

@@ -54,6 +54,54 @@ int thread_suspend(struct ktcb *task)
 	return thread_signal(task, TASK_SUSPENDING, TASK_INACTIVE);
 }
 
+static inline int TASK_IS_CHILD(struct ktcb *task)
+{
+	return (((task) != current) &&
+		((task)->pagerid == current->tid));
+}
+
+int thread_delete_children(void)
+{
+	struct ktcb *task, *n;
+
+	spin_lock(&curcont->ktcb_list.list_lock);
+	list_foreach_removable_struct(task, n,
+				      &curcont->ktcb_list.list,
+				      task_list) {
+		if (TASK_IS_CHILD(task)) {
+			spin_unlock(&curcont->ktcb_list.list_lock);
+			tcb_remove(task);
+			wake_up_all(&current->wqh_send, 0);
+			wake_up_all(&current->wqh_recv, 0);
+			BUG_ON(task->wqh_pager.sleepers > 0);
+			BUG_ON(task->state != TASK_INACTIVE);
+			tcb_delete(task);
+			spin_lock(&curcont->ktcb_list.list_lock);
+		}
+	}
+	spin_unlock(&curcont->ktcb_list.list_lock);
+	return 0;
+}
+
+int thread_suspend_children(void)
+{
+	struct ktcb *task, *n;
+
+	spin_lock(&curcont->ktcb_list.list_lock);
+	list_foreach_removable_struct(task, n,
+				      &curcont->ktcb_list.list,
+				      task_list) {
+		if (TASK_IS_CHILD(task)) {
+			spin_unlock(&curcont->ktcb_list.list_lock);
+			thread_suspend(task);
+			spin_lock(&curcont->ktcb_list.list_lock);
+		}
+	}
+	spin_unlock(&curcont->ktcb_list.list_lock);
+	return 0;
+
+}
+
 /*
  * Put them in TASK_DEAD so that a suspended exiting thread
  * does not run again if issued THREAD_RUN
@@ -61,20 +109,23 @@ int thread_suspend(struct ktcb *task)
 int thread_destroy(struct ktcb *task)
 {
 	if (task == current) {
-		if (current->tid == current->pagerid)
+		if (current->tid == current->pagerid) {
+			/* Suspend children */
+			thread_suspend_children();
+			thread_delete_children();
 			sched_exit_pager();
-		else
+		} else {
 			sched_suspend_sync();
+		}
 		return 0;
 	}
-
 	thread_suspend(task);
 
 	tcb_remove(task);
 
 	/* Wake up waiters */
-	wake_up_all(&current->wqh_send, 0);
-	wake_up_all(&current->wqh_recv, 0);
+	wake_up_all(&task->wqh_send, 0);
+	wake_up_all(&task->wqh_recv, 0);
 
 	BUG_ON(task->wqh_pager.sleepers > 0);
 	BUG_ON(task->state != TASK_INACTIVE);

src/arch/arm/exception.c

@@ -21,7 +21,7 @@
 #include INC_SUBARCH(mm.h)
 
 /* Abort debugging conditions */
-// #define DEBUG_ABORTS
+//#define DEBUG_ABORTS
 #if defined (DEBUG_ABORTS)
 #define dbg_abort(...)	dprintk(__VA_ARGS__)
 #else

src/generic/irq.c

@@ -74,11 +74,9 @@ void do_irq(void)
 		printk("Spurious or broken irq\n"); BUG();
 	}
 	irq_enable(irq_index);
-
 #if 0
 	/* Process any pending flags for currently runnable task */
 	if (!in_nested_irq_context()) {
-		/* This is buggy, races on prio_total */
 		if (in_user()) {
 			if (current->flags & TASK_SUSPENDING)
 				sched_suspend_async();

src/lib/wait.c

@@ -107,11 +107,11 @@ int wait_on(struct waitqueue_head *wqh)
 	return 0;
 }
 
-/* Wake up all - FIXME: this is buggy with double spin_unlock */
+/* Wake up all in the queue */
 void wake_up_all(struct waitqueue_head *wqh, unsigned int flags)
 {
-	BUG_ON(wqh->sleepers < 0);
 	spin_lock(&wqh->slock);
+	BUG_ON(wqh->sleepers < 0);
 	while (wqh->sleepers > 0) {
 		struct waitqueue *wq = link_to_struct(wqh->task_list.next,
 						  struct waitqueue,
@@ -130,6 +130,8 @@ void wake_up_all(struct waitqueue_head *wqh, unsigned int flags)
 			sched_resume_sync(sleeper);
 		else
 			sched_resume_async(sleeper);
+
+		spin_lock(&wqh->slock);
 	}
 	spin_unlock(&wqh->slock);
 }
@@ -150,7 +152,7 @@ void wake_up(struct waitqueue_head *wqh, unsigned int flags)
 		task_unset_wqh(sleeper);
 		if (flags & WAKEUP_INTERRUPT)
 			sleeper->flags |= TASK_INTERRUPTED;
-		// printk("(%d) Waking up (%d)\n", current->tid, sleeper->tid);
+		//printk("(%d) Waking up (%d)\n", current->tid, sleeper->tid);
 		spin_unlock(&wqh->slock);
 
 		if (flags & WAKEUP_SYNC)