From: Davidlohr Bueso <davidlohr.bueso@hp.com>
Date: Mon, 8 Jul 2013 23:01:10 +0000 (-0700)
Subject: ipc: introduce ipc object locking helpers
X-Git-Tag: firefly_0821_release~6453^2~508
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=9f7b399c9dbc71bd09d5b45242a6fb8fbf2650a3;p=firefly-linux-kernel-4.4.55.git

ipc: introduce ipc object locking helpers

commit 1ca7003ab41152d673d9e359632283d05294f3d6 upstream.

Simple helpers around the (kern_ipc_perm *)->lock spinlock.

Signed-off-by: Davidlohr Bueso <davidlohr.bueso@hp.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/ipc/util.h b/ipc/util.h
index 2b0bdd5d92ce..da65e8afb8f4 100644
--- a/ipc/util.h
+++ b/ipc/util.h
@@ -159,23 +159,33 @@ static inline int ipc_checkid(struct kern_ipc_perm *ipcp, int uid)
 	return uid / SEQ_MULTIPLIER != ipcp->seq;
 }
 
-static inline void ipc_lock_by_ptr(struct kern_ipc_perm *perm)
+static inline void ipc_lock_object(struct kern_ipc_perm *perm)
 {
-	rcu_read_lock();
 	spin_lock(&perm->lock);
 }
 
-static inline void ipc_unlock(struct kern_ipc_perm *perm)
+static inline void ipc_unlock_object(struct kern_ipc_perm *perm)
 {
 	spin_unlock(&perm->lock);
-	rcu_read_unlock();
 }
 
-static inline void ipc_lock_object(struct kern_ipc_perm *perm)
+static inline void ipc_assert_locked_object(struct kern_ipc_perm *perm)
 {
+	assert_spin_locked(&perm->lock);
+}
+
+static inline void ipc_lock_by_ptr(struct kern_ipc_perm *perm)
+{
+	rcu_read_lock();
 	spin_lock(&perm->lock);
 }
 
+static inline void ipc_unlock(struct kern_ipc_perm *perm)
+{
+	spin_unlock(&perm->lock);
+	rcu_read_unlock();
+}
+
 struct kern_ipc_perm *ipc_lock_check(struct ipc_ids *ids, int id);
 struct kern_ipc_perm *ipc_obtain_object_check(struct ipc_ids *ids, int id);
 int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids,