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, 29 insertions, 47 deletions

diff --git a/ipc/sem.c b/ipc/sem.c
index f92a2565d12..6af226af0b9 100644
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -97,7 +97,7 @@
 
 static struct ipc_ids init_sem_ids;
 
-static int newary(struct ipc_namespace *, key_t, int, int);
+static int newary(struct ipc_namespace *, struct ipc_params *);
 static void freeary(struct ipc_namespace *, struct sem_array *);
 #ifdef CONFIG_PROC_FS
 static int sysvipc_sem_proc_show(struct seq_file *s, void *it);
@@ -214,12 +214,15 @@ static inline void sem_rmid(struct ipc_namespace *ns, struct sem_array *s)
  */
 #define IN_WAKEUP       1
 
-static int newary (struct ipc_namespace *ns, key_t key, int nsems, int semflg)
+static int newary(struct ipc_namespace *ns, struct ipc_params *params)
 {
         int id;
         int retval;
         struct sem_array *sma;
         int size;
+        key_t key = params->key;
+        int nsems = params->u.nsems;
+        int semflg = params->flg;
 
         if (!nsems)
                 return -EINVAL;
@@ -263,61 +266,40 @@ static int newary (struct ipc_namespace *ns, key_t key, int nsems, int semflg)
         return sma->sem_perm.id;
 }
 
-asmlinkage long sys_semget (key_t key, int nsems, int semflg)
+
+static inline int sem_security(void *sma, int semflg)
+{
+        return security_sem_associate((struct sem_array *) sma, semflg);
+}
+
+static inline int sem_more_checks(void *sma, struct ipc_params *params)
+{
+        if (params->u.nsems > ((struct sem_array *)sma)->sem_nsems)
+                return -EINVAL;
+
+        return 0;
+}
+
+asmlinkage long sys_semget(key_t key, int nsems, int semflg)
 {
-        int err;
-        struct sem_array *sma;
         struct ipc_namespace *ns;
+        struct ipc_ops sem_ops;
+        struct ipc_params sem_params;
 
         ns = current->nsproxy->ipc_ns;
 
         if (nsems < 0 || nsems > ns->sc_semmsl)
                 return -EINVAL;
 
-        err = idr_pre_get(&sem_ids(ns).ipcs_idr, GFP_KERNEL);
+        sem_ops.getnew = newary;
+        sem_ops.associate = sem_security;
+        sem_ops.more_checks = sem_more_checks;
 
-        if (key == IPC_PRIVATE) {
-                if (!err)
-                        err = -ENOMEM;
-                else {
-                        mutex_lock(&sem_ids(ns).mutex);
-                        err = newary(ns, key, nsems, semflg);
-                        mutex_unlock(&sem_ids(ns).mutex);
-                }
-        } else {
-                mutex_lock(&sem_ids(ns).mutex);
-                sma = (struct sem_array *) ipc_findkey(&sem_ids(ns), key);
-                if (sma == NULL) {
-                        /* key not used */
-                        if (!(semflg & IPC_CREAT))
-                                err = -ENOENT;
-                        else if (!err)
-                                err = -ENOMEM;
-                        else
-                                err = newary(ns, key, nsems, semflg);
-                } else {
-                        /* sma has been locked by ipc_findkey() */
-
-                        if (semflg & IPC_CREAT && semflg & IPC_EXCL)
-                                err = -EEXIST;
-                        else {
-                                if (nsems > sma->sem_nsems)
-                                        err = -EINVAL;
-                                else if (ipcperms(&sma->sem_perm, semflg))
-                                        err = -EACCES;
-                                else {
-                                        err = security_sem_associate(sma,
-                                                                semflg);
-                                        if (!err)
-                                                err = sma->sem_perm.id;
-                                }
-                        }
-                        sem_unlock(sma);
-                }
-                mutex_unlock(&sem_ids(ns).mutex);
-        }
+        sem_params.key = key;
+        sem_params.flg = semflg;
+        sem_params.u.nsems = nsems;
 
-        return err;
+        return ipcget(ns, &sem_ids(ns), &sem_ops, &sem_params);
 }
 
 /* Manage the doubly linked list sma->sem_pending as a FIFO: