[PATCH 4/5] include/linux/sem.h: make sysv_sem empty if SYSVIPC is disabled

[Manfred Spraul <manfred@colorfullife.com>]

For the sysvsem undo, each task struct contains a sysv_sem structure
with a pointer to the undo information.
This pointer is only necessary if sysvipc is enabled - thus
the pointer can be made conditional on CONFIG_SYSVIPC.

Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
---
 include/linux/sem.h |    9 +++++++--
 1 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/include/linux/sem.h b/include/linux/sem.h
index 4648426..10d6b22 100644
--- a/include/linux/sem.h
+++ b/include/linux/sem.h
@@ -96,16 +96,21 @@ struct sem_array {
 	int			complex_count;	/* pending complex operations */
 };
 
+#ifdef CONFIG_SYSVIPC
+
 struct sysv_sem {
 	struct sem_undo_list *undo_list;
 };
 
-#ifdef CONFIG_SYSVIPC
-
 extern int copy_semundo(unsigned long clone_flags, struct task_struct *tsk);
 extern void exit_sem(struct task_struct *tsk);
 
 #else
+
+struct sysv_sem {
+	/* empty */
+};
+
 static inline int copy_semundo(unsigned long clone_flags, struct task_struct *tsk)
 {
 	return 0;
-- 
1.7.6.4