ipc: move atomic_set() to where it is needed

Only after ipc_addid() has succeeded will refcounting be used, so move initialization into ipc_addid() and remove from open-coded *_alloc() routines. Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Kees Cook <[email protected]> Signed-off-by: Manfred Spraul <[email protected]> Cc: Davidlohr Bueso <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
beyond2002 · Jul 12, 2017 · 3d3653f · 3d3653f
1 parent 51c23b7
commit 3d3653f
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Showing 4 changed files with 1 addition and 5 deletions.
diff --git a/ipc/msg.c b/ipc/msg.c
@@ -117,8 +117,6 @@ static struct msg_queue *msg_alloc(void)
 	if (unlikely(!msq))
 		return NULL;
 
-	atomic_set(&msq->q_perm.refcount, 1);
-
 	return msq;
 }
 

diff --git a/ipc/sem.c b/ipc/sem.c
@@ -465,7 +465,6 @@ static struct sem_array *sem_alloc(size_t nsems)
 		return NULL;
 
 	memset(sma, 0, size);
-	atomic_set(&sma->sem_perm.refcount, 1);
 
 	return sma;
 }

diff --git a/ipc/shm.c b/ipc/shm.c
@@ -526,8 +526,6 @@ static struct shmid_kernel *shm_alloc(void)
 	if (unlikely(!shp))
 		return NULL;
 
-	atomic_set(&shp->shm_perm.refcount, 1);
-
 	return shp;
 }
 

diff --git a/ipc/util.c b/ipc/util.c
@@ -232,6 +232,7 @@ int ipc_addid(struct ipc_ids *ids, struct kern_ipc_perm *new, int size)
 
 	idr_preload(GFP_KERNEL);
 
+	atomic_set(&new->refcount, 1);
 	spin_lock_init(&new->lock);
 	new->deleted = false;
 	rcu_read_lock();