[PATCH 02/11] ipc: introduce ipc object locking helpers

From: Davidlohr Bueso
Date: Wed May 15 2013 - 21:09:29 EST


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

Signed-off-by: Davidlohr Bueso <davidlohr.bueso@xxxxxx>
---
ipc/util.h | 20 +++++++++++++++-----
1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/ipc/util.h b/ipc/util.h
index 2b0bdd5..da65e8a 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,
--
1.7.11.7

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