Added child utcb initialisation to fork call implementation in libposix.

tasks/libl4/include/l4lib/utcb.h

@@ -7,4 +7,6 @@
 #include <l4lib/types.h>
 #include <l4lib/arch/utcb.h>
 
+int utcb_init(void);
+
 #endif /* __UTCB_H__ */

tasks/libl4/src/init.c

@@ -75,7 +75,8 @@ static void *l4_utcb_page(void)
 
 /*
  * Initialises a non-pager task's shared memory utcb page
- * using posix semantics.
+ * using posix semantics. Used during task initialisation
+ * and by child tasks after a fork.
  */
 int utcb_init(void)
 {

tasks/libposix/fork.c

@@ -39,8 +39,11 @@ int fork(void)
 		errno = -ret;
 		return -1;
 	}
-	/* else return value */
-	return ret;
 
+	/* If we're a child, we need to initialise the utcb page */
+	if (ret == 0)
+		utcb_init();
+
+	return ret;
 }