diff --git a/include/linux/taskstats_kern.h b/include/linux/taskstats_kern.h
index 6642240..6562a20 100644
--- a/include/linux/taskstats_kern.h
+++ b/include/linux/taskstats_kern.h
@@ -23,28 +23,26 @@
 
 static inline void taskstats_tgid_init(struct signal_struct *sig)
 {
-	spin_lock_init(&sig->stats_lock);
 	sig->stats = NULL;
 }
 
-static inline void taskstats_tgid_alloc(struct signal_struct *sig)
+static inline void taskstats_tgid_alloc(struct task_struct *tsk)
 {
+	struct signal_struct *sig = tsk->signal;
 	struct taskstats *stats;
-	unsigned long flags;
 
 	if (sig->stats != NULL)
 		return;
 
+	/* No problem if kmem_cache_zalloc() fails */
 	stats = kmem_cache_zalloc(taskstats_cache, SLAB_KERNEL);
-	if (!stats)
-		return;
 
-	spin_lock_irqsave(&sig->stats_lock, flags);
+	spin_lock_irq(&tsk->sighand->siglock);
 	if (!sig->stats) {
 		sig->stats = stats;
 		stats = NULL;
 	}
-	spin_unlock_irqrestore(&sig->stats_lock, flags);
+	spin_unlock_irq(&tsk->sighand->siglock);
 
 	if (stats)
 		kmem_cache_free(taskstats_cache, stats);
@@ -59,7 +57,6 @@
 extern void taskstats_exit_alloc(struct taskstats **, unsigned int *);
 extern void taskstats_exit_send(struct task_struct *, struct taskstats *, int, unsigned int);
 extern void taskstats_init_early(void);
-extern void taskstats_tgid_alloc(struct signal_struct *);
 #else
 static inline void taskstats_exit_alloc(struct taskstats **ptidstats, unsigned int *mycpu)
 {}
@@ -71,7 +68,7 @@
 {}
 static inline void taskstats_tgid_init(struct signal_struct *sig)
 {}
-static inline void taskstats_tgid_alloc(struct signal_struct *sig)
+static inline void taskstats_tgid_alloc(struct task_struct *tsk)
 {}
 static inline void taskstats_tgid_free(struct signal_struct *sig)
 {}