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-rw-r--r--ipc/shm.c29
-rw-r--r--ipc/util.c36
-rw-r--r--ipc/util.h1
3 files changed, 23 insertions, 43 deletions
diff --git a/ipc/shm.c b/ipc/shm.c
index a413ddf74dac..4c7ae625d996 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -180,16 +180,33 @@ static inline struct shmid_kernel *shm_obtain_object_check(struct ipc_namespace
*/
static inline struct shmid_kernel *shm_lock(struct ipc_namespace *ns, int id)
{
- struct kern_ipc_perm *ipcp = ipc_lock(&shm_ids(ns), id);
+ struct kern_ipc_perm *ipcp;
+
+ rcu_read_lock();
+ ipcp = ipc_obtain_object_idr(&shm_ids(ns), id);
+ if (IS_ERR(ipcp))
+ goto err;
+ ipc_lock_object(ipcp);
+ /*
+ * ipc_rmid() may have already freed the ID while ipc_lock_object()
+ * was spinning: here verify that the structure is still valid.
+ * Upon races with RMID, return -EIDRM, thus indicating that
+ * the ID points to a removed identifier.
+ */
+ if (ipc_valid_object(ipcp)) {
+ /* return a locked ipc object upon success */
+ return container_of(ipcp, struct shmid_kernel, shm_perm);
+ }
+
+ ipc_unlock_object(ipcp);
+err:
+ rcu_read_unlock();
/*
* Callers of shm_lock() must validate the status of the returned ipc
- * object pointer (as returned by ipc_lock()), and error out as
- * appropriate.
+ * object pointer and error out as appropriate.
*/
- if (IS_ERR(ipcp))
- return (void *)ipcp;
- return container_of(ipcp, struct shmid_kernel, shm_perm);
+ return (void *)ipcp;
}
static inline void shm_lock_by_ptr(struct shmid_kernel *ipcp)
diff --git a/ipc/util.c b/ipc/util.c
index dcb437095cbd..bd1863b6ed39 100644
--- a/ipc/util.c
+++ b/ipc/util.c
@@ -589,42 +589,6 @@ struct kern_ipc_perm *ipc_obtain_object_idr(struct ipc_ids *ids, int id)
}
/**
- * ipc_lock - lock an ipc structure without rwsem held
- * @ids: ipc identifier set
- * @id: ipc id to look for
- *
- * Look for an id in the ipc ids idr and lock the associated ipc object.
- *
- * The ipc object is locked on successful exit.
- */
-struct kern_ipc_perm *ipc_lock(struct ipc_ids *ids, int id)
-{
- struct kern_ipc_perm *out;
-
- rcu_read_lock();
- out = ipc_obtain_object_idr(ids, id);
- if (IS_ERR(out))
- goto err;
-
- spin_lock(&out->lock);
-
- /*
- * ipc_rmid() may have already freed the ID while ipc_lock()
- * was spinning: here verify that the structure is still valid.
- * Upon races with RMID, return -EIDRM, thus indicating that
- * the ID points to a removed identifier.
- */
- if (ipc_valid_object(out))
- return out;
-
- spin_unlock(&out->lock);
- out = ERR_PTR(-EIDRM);
-err:
- rcu_read_unlock();
- return out;
-}
-
-/**
* ipc_obtain_object_check
* @ids: ipc identifier set
* @id: ipc id to look for
diff --git a/ipc/util.h b/ipc/util.h
index fcf81425ae98..e3c47b21db93 100644
--- a/ipc/util.h
+++ b/ipc/util.h
@@ -142,7 +142,6 @@ int ipc_rcu_getref(struct kern_ipc_perm *ptr);
void ipc_rcu_putref(struct kern_ipc_perm *ptr,
void (*func)(struct rcu_head *head));
-struct kern_ipc_perm *ipc_lock(struct ipc_ids *, int);
struct kern_ipc_perm *ipc_obtain_object_idr(struct ipc_ids *ids, int id);
void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out);