ipc: fix wrong comments

This patch fixes the wrong / obsolete comments in the ipc code.  Also adds
a missing lock around ipc_get_maxid() in shm_get_stat().

Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/ipc/util.h b/ipc/util.h
index 76f8a79..99414a3 100644
--- a/ipc/util.h
+++ b/ipc/util.h
@@ -54,7 +54,7 @@
  * the calls to sys_msgget(), sys_semget(), sys_shmget()
  *      . routine to call to create a new ipc object. Can be one of newque,
  *        newary, newseg
- *      . routine to call to call to check permissions for a new ipc object.
+ *      . routine to call to check permissions for a new ipc object.
  *        Can be one of security_msg_associate, security_sem_associate,
  *        security_shm_associate
  *      . routine to call for an extra check if needed
@@ -88,7 +88,8 @@
 /* must be called with both locks acquired. */
 void ipc_rmid(struct ipc_ids *, struct kern_ipc_perm *);
 
-int ipcperms (struct kern_ipc_perm *ipcp, short flg);
+/* must be called with ipcp locked */
+int ipcperms(struct kern_ipc_perm *ipcp, short flg);
 
 /* for rare, potentially huge allocations.
  * both function can sleep
@@ -131,6 +132,9 @@
 	return SEQ_MULTIPLIER * seq + id;
 }
 
+/*
+ * Must be called with ipcp locked
+ */
 static inline int ipc_checkid(struct ipc_ids *ids, struct kern_ipc_perm *ipcp,
 				int uid)
 {
@@ -168,6 +172,16 @@
 	return out;
 }
 
+/**
+ * ipcget - Common sys_*get() code
+ * @ns : namsepace
+ * @ids : IPC identifier set
+ * @ops : operations to be called on ipc object creation, permission checks
+ *        and further checks
+ * @params : the parameters needed by the previous operations.
+ *
+ * Common routine called by sys_msgget(), sys_semget() and sys_shmget().
+ */
 static inline int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids,
 			struct ipc_ops *ops, struct ipc_params *params)
 {