ipc: unify the syscalls code
This patch introduces a change into the sys_msgget(), sys_semget() and
sys_shmget() routines: they now share a common code, which is better for
maintainability.
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.c b/ipc/util.c
index 2a20587..03b8879 100644
--- a/ipc/util.c
+++ b/ipc/util.c
@@ -197,7 +197,7 @@
* If key is found ipc contains its ipc structure
*/
-struct kern_ipc_perm *ipc_findkey(struct ipc_ids *ids, key_t key)
+static struct kern_ipc_perm *ipc_findkey(struct ipc_ids *ids, key_t key)
{
struct kern_ipc_perm *ipc;
int next_id;
@@ -301,6 +301,105 @@
}
/**
+ * ipcget_new - create a new ipc object
+ * @ns: namespace
+ * @ids: identifer set
+ * @ops: the actual creation routine to call
+ * @params: its parameters
+ *
+ * This routine is called sys_msgget, sys_semget() and sys_shmget() when
+ * the key is IPC_PRIVATE
+ */
+int ipcget_new(struct ipc_namespace *ns, struct ipc_ids *ids,
+ struct ipc_ops *ops, struct ipc_params *params)
+{
+ int err;
+
+ err = idr_pre_get(&ids->ipcs_idr, GFP_KERNEL);
+
+ if (!err)
+ return -ENOMEM;
+
+ mutex_lock(&ids->mutex);
+ err = ops->getnew(ns, params);
+ mutex_unlock(&ids->mutex);
+
+ return err;
+}
+
+/**
+ * ipc_check_perms - check security and permissions for an IPC
+ * @ipcp: ipc permission set
+ * @ids: identifer set
+ * @ops: the actual security routine to call
+ * @params: its parameters
+ */
+static int ipc_check_perms(struct kern_ipc_perm *ipcp, struct ipc_ops *ops,
+ struct ipc_params *params)
+{
+ int err;
+
+ if (ipcperms(ipcp, params->flg))
+ err = -EACCES;
+ else {
+ err = ops->associate(ipcp, params->flg);
+ if (!err)
+ err = ipcp->id;
+ }
+
+ return err;
+}
+
+/**
+ * ipcget_public - get an ipc object or create a new one
+ * @ns: namespace
+ * @ids: identifer set
+ * @ops: the actual creation routine to call
+ * @params: its parameters
+ *
+ * This routine is called sys_msgget, sys_semget() and sys_shmget() when
+ * the key is not IPC_PRIVATE
+ */
+int ipcget_public(struct ipc_namespace *ns, struct ipc_ids *ids,
+ struct ipc_ops *ops, struct ipc_params *params)
+{
+ struct kern_ipc_perm *ipcp;
+ int flg = params->flg;
+ int err;
+
+ err = idr_pre_get(&ids->ipcs_idr, GFP_KERNEL);
+
+ mutex_lock(&ids->mutex);
+ ipcp = ipc_findkey(ids, params->key);
+ if (ipcp == NULL) {
+ /* key not used */
+ if (!(flg & IPC_CREAT))
+ err = -ENOENT;
+ else if (!err)
+ err = -ENOMEM;
+ else
+ err = ops->getnew(ns, params);
+ } else {
+ /* ipc object has been locked by ipc_findkey() */
+
+ if (flg & IPC_CREAT && flg & IPC_EXCL)
+ err = -EEXIST;
+ else {
+ err = 0;
+ if (ops->more_checks)
+ err = ops->more_checks(ipcp, params);
+ if (!err)
+ err = ipc_check_perms(ipcp, ops, params);
+ }
+ ipc_unlock(ipcp);
+ }
+ mutex_unlock(&ids->mutex);
+
+ return err;
+}
+
+
+/**
* ipc_rmid - remove an IPC identifier
* @ids: identifier set
* @id: ipc perm structure containing the identifier to remove