IPC/semaphores: consolidate SEM_STAT and IPC_STAT commands

These commands (SEM_STAT and IPC_STAT) are rather doing the same things
(only the meaning of the id given as input and the return value differ).
However, for the semaphores, they are handled in two different places (two
different functions).

This patch consolidates this for clarification by handling these both
commands in the same place in semctl_nolock().  It also removes one unused
parameter for this function.

Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net>
Cc: 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/sem.c b/ipc/sem.c
index 84c701f..7836edb 100644
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -617,8 +617,8 @@
 	}
 }
 
-static int semctl_nolock(struct ipc_namespace *ns, int semid, int semnum,
-		int cmd, int version, union semun arg)
+static int semctl_nolock(struct ipc_namespace *ns, int semid,
+			 int cmd, int version, union semun arg)
 {
 	int err = -EINVAL;
 	struct sem_array *sma;
@@ -657,14 +657,23 @@
 			return -EFAULT;
 		return (max_id < 0) ? 0: max_id;
 	}
+	case IPC_STAT:
 	case SEM_STAT:
 	{
 		struct semid64_ds tbuf;
 		int id;
 
-		sma = sem_lock(ns, semid);
-		if (IS_ERR(sma))
-			return PTR_ERR(sma);
+		if (cmd == SEM_STAT) {
+			sma = sem_lock(ns, semid);
+			if (IS_ERR(sma))
+				return PTR_ERR(sma);
+			id = sma->sem_perm.id;
+		} else {
+			sma = sem_lock_check(ns, semid);
+			if (IS_ERR(sma))
+				return PTR_ERR(sma);
+			id = 0;
+		}
 
 		err = -EACCES;
 		if (ipcperms (&sma->sem_perm, S_IRUGO))
@@ -674,8 +683,6 @@
 		if (err)
 			goto out_unlock;
 
-		id = sma->sem_perm.id;
-
 		memset(&tbuf, 0, sizeof(tbuf));
 
 		kernel_to_ipc64_perm(&sma->sem_perm, &tbuf.sem_perm);
@@ -810,19 +817,6 @@
 		err = 0;
 		goto out_unlock;
 	}
-	case IPC_STAT:
-	{
-		struct semid64_ds tbuf;
-		memset(&tbuf,0,sizeof(tbuf));
-		kernel_to_ipc64_perm(&sma->sem_perm, &tbuf.sem_perm);
-		tbuf.sem_otime  = sma->sem_otime;
-		tbuf.sem_ctime  = sma->sem_ctime;
-		tbuf.sem_nsems  = sma->sem_nsems;
-		sem_unlock(sma);
-		if (copy_semid_to_user (arg.buf, &tbuf, version))
-			return -EFAULT;
-		return 0;
-	}
 	/* GETVAL, GETPID, GETNCTN, GETZCNT, SETVAL: fall-through */
 	}
 	err = -EINVAL;
@@ -989,15 +983,15 @@
 	switch(cmd) {
 	case IPC_INFO:
 	case SEM_INFO:
+	case IPC_STAT:
 	case SEM_STAT:
-		err = semctl_nolock(ns,semid,semnum,cmd,version,arg);
+		err = semctl_nolock(ns, semid, cmd, version, arg);
 		return err;
 	case GETALL:
 	case GETVAL:
 	case GETPID:
 	case GETNCNT:
 	case GETZCNT:
-	case IPC_STAT:
 	case SETVAL:
 	case SETALL:
 		err = semctl_main(ns,semid,semnum,cmd,version,arg);