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>

1 files changed, 42 insertions, 1 deletions

diff --git a/ipc/util.h b/ipc/util.h
index c9063267d4f8..30b2a6d7cbed 100644
--- a/ipc/util.h
+++ b/ipc/util.h
@@ -35,6 +35,35 @@ struct ipc_ids {
         struct idr ipcs_idr;
 };
 
+/*
+ * Structure that holds the parameters needed by the ipc operations
+ * (see after)
+ */
+struct ipc_params {
+        key_t key;
+        int flg;
+        union {
+                size_t size;    /* for shared memories */
+                int nsems;      /* for semaphores */
+        } u;                    /* holds the getnew() specific param */
+};
+
+/*
+ * Structure that holds some ipc operations. This structure is used to unify
+ * the calls to sys_msgget(), sys_semget(), sys_shmget()
+ *      . routine to call to create a new ipc object. Can be one of newque,
+ *        newary, newseg
+ *      . routine to call to call to check permissions for a new ipc object.
+ *        Can be one of security_msg_associate, security_sem_associate,
+ *        security_shm_associate
+ *      . routine to call for an extra check if needed
+ */
+struct ipc_ops {
+        int (*getnew) (struct ipc_namespace *, struct ipc_params *);
+        int (*associate) (void *, int);
+        int (*more_checks) (void *, struct ipc_params *);
+};
+
 struct seq_file;
 
 void ipc_init_ids(struct ipc_ids *);
@@ -50,7 +79,6 @@ void __init ipc_init_proc_interface(const char *path, const char *header,
 #define IPC_SHM_IDS     2
 
 /* must be called with ids->mutex acquired.*/
-struct kern_ipc_perm *ipc_findkey(struct ipc_ids *ids, key_t key);
 int ipc_addid(struct ipc_ids *, struct kern_ipc_perm *, int);
 int ipc_get_maxid(struct ipc_ids *);
 
@@ -95,5 +123,18 @@ int ipc_parse_version (int *cmd);
 extern void free_msg(struct msg_msg *msg);
 extern struct msg_msg *load_msg(const void __user *src, int len);
 extern int store_msg(void __user *dest, struct msg_msg *msg, int len);
+extern int ipcget_new(struct ipc_namespace *, struct ipc_ids *,
+                        struct ipc_ops *, struct ipc_params *);
+extern int ipcget_public(struct ipc_namespace *, struct ipc_ids *,
+                        struct ipc_ops *, struct ipc_params *);
+
+static inline int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids,
+                        struct ipc_ops *ops, struct ipc_params *params)
+{
+        if (params->key == IPC_PRIVATE)
+                return ipcget_new(ns, ids, ops, params);
+        else
+                return ipcget_public(ns, ids, ops, params);
+}
 
 #endif