IPC: get rid of the use *_setbuf structure.

All IPCs make use of an intermetiate *_setbuf structure to handle the IPC_SET
command.  This is not really needed and, moreover, it complicates a little bit
the code.

This patch gets rid of the use of it and uses directly the semid64_ds/
msgid64_ds/shmid64_ds structure.

In addition of removing one struture declaration, it also simplifies and
improves a little bit the common 64-bits path.

Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net>
Acked-by: Serge Hallyn <serue@us.ibm.com>
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>

1 files changed, 18 insertions, 33 deletions

diff --git a/ipc/msg.c b/ipc/msg.c
index 9d868b3d3329..80375bf43d7b 100644
--- a/ipc/msg.c
+++ b/ipc/msg.c
@@ -388,31 +388,14 @@ copy_msqid_to_user(void __user *buf, struct msqid64_ds *in, int version)
 	}
 }
 
-struct msq_setbuf {
-	unsigned long	qbytes;
-	uid_t		uid;
-	gid_t		gid;
-	mode_t		mode;
-};
-
 static inline unsigned long
-copy_msqid_from_user(struct msq_setbuf *out, void __user *buf, int version)
+copy_msqid_from_user(struct msqid64_ds *out, void __user *buf, int version)
 {
 	switch(version) {
 	case IPC_64:
-	{
-		struct msqid64_ds tbuf;
-
-		if (copy_from_user(&tbuf, buf, sizeof(tbuf)))
+		if (copy_from_user(out, buf, sizeof(*out)))
 			return -EFAULT;
-
-		out->qbytes		= tbuf.msg_qbytes;
-		out->uid		= tbuf.msg_perm.uid;
-		out->gid		= tbuf.msg_perm.gid;
-		out->mode		= tbuf.msg_perm.mode;
-
 		return 0;
-	}
 	case IPC_OLD:
 	{
 		struct msqid_ds tbuf_old;
@@ -420,14 +403,14 @@ copy_msqid_from_user(struct msq_setbuf *out, void __user *buf, int version)
 		if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
 			return -EFAULT;
 
-		out->uid		= tbuf_old.msg_perm.uid;
-		out->gid		= tbuf_old.msg_perm.gid;
-		out->mode		= tbuf_old.msg_perm.mode;
+		out->msg_perm.uid      	= tbuf_old.msg_perm.uid;
+		out->msg_perm.gid      	= tbuf_old.msg_perm.gid;
+		out->msg_perm.mode     	= tbuf_old.msg_perm.mode;
 
 		if (tbuf_old.msg_qbytes == 0)
-			out->qbytes	= tbuf_old.msg_lqbytes;
+			out->msg_qbytes	= tbuf_old.msg_lqbytes;
 		else
-			out->qbytes	= tbuf_old.msg_qbytes;
+			out->msg_qbytes	= tbuf_old.msg_qbytes;
 
 		return 0;
 	}
@@ -445,12 +428,12 @@ static int msgctl_down(struct ipc_namespace *ns, int msqid, int cmd,
 		       struct msqid_ds __user *buf, int version)
 {
 	struct kern_ipc_perm *ipcp;
-	struct msq_setbuf setbuf;
+	struct msqid64_ds msqid64;
 	struct msg_queue *msq;
 	int err;
 
 	if (cmd == IPC_SET) {
-		if (copy_msqid_from_user(&setbuf, buf, version))
+		if (copy_msqid_from_user(&msqid64, buf, version))
 			return -EFAULT;
 	}
 
@@ -468,8 +451,10 @@ static int msgctl_down(struct ipc_namespace *ns, int msqid, int cmd,
 		goto out_unlock;
 
 	if (cmd == IPC_SET) {
-		err = audit_ipc_set_perm(setbuf.qbytes, setbuf.uid, setbuf.gid,
-					 setbuf.mode);
+		err = audit_ipc_set_perm(msqid64.msg_qbytes,
+					 msqid64.msg_perm.uid,
+					 msqid64.msg_perm.gid,
+					 msqid64.msg_perm.mode);
 		if (err)
 			goto out_unlock;
 	}
@@ -491,18 +476,18 @@ static int msgctl_down(struct ipc_namespace *ns, int msqid, int cmd,
 		freeque(ns, ipcp);
 		goto out_up;
 	case IPC_SET:
-		if (setbuf.qbytes > ns->msg_ctlmnb &&
+		if (msqid64.msg_qbytes > ns->msg_ctlmnb &&
 		    !capable(CAP_SYS_RESOURCE)) {
 			err = -EPERM;
 			goto out_unlock;
 		}
 
-		msq->q_qbytes = setbuf.qbytes;
+		msq->q_qbytes = msqid64.msg_qbytes;
 
-		ipcp->uid = setbuf.uid;
-		ipcp->gid = setbuf.gid;
+		ipcp->uid = msqid64.msg_perm.uid;
+		ipcp->gid = msqid64.msg_perm.gid;
 		ipcp->mode = (ipcp->mode & ~S_IRWXUGO) |
-			     (S_IRWXUGO & setbuf.mode);
+			     (S_IRWXUGO & msqid64.msg_perm.mode);
 		msq->q_ctime = get_seconds();
 		/* sleeping receivers might be excluded by
 		 * stricter permissions.