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>

3 files changed, 46 insertions, 86 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.
diff --git a/ipc/sem.c b/ipc/sem.c
index db161decb764..df98de290475 100644
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -835,28 +835,14 @@ out_free:
         return err;
 }
 
-struct sem_setbuf {
-        uid_t   uid;
-        gid_t   gid;
-        mode_t  mode;
-};
-
-static inline unsigned long copy_semid_from_user(struct sem_setbuf *out, void __user *buf, int version)
+static inline unsigned long
+copy_semid_from_user(struct semid64_ds *out, void __user *buf, int version)
 {
         switch(version) {
         case IPC_64:
-            {
-                struct semid64_ds tbuf;
-
-                if(copy_from_user(&tbuf, buf, sizeof(tbuf)))
+                if (copy_from_user(out, buf, sizeof(*out)))
                         return -EFAULT;
-
-                out->uid        = tbuf.sem_perm.uid;
-                out->gid        = tbuf.sem_perm.gid;
-                out->mode       = tbuf.sem_perm.mode;
-
                 return 0;
-            }
         case IPC_OLD:
             {
                 struct semid_ds tbuf_old;
@@ -864,9 +850,9 @@ static inline unsigned long copy_semid_from_user(struct sem_setbuf *out, void __
                 if(copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
                         return -EFAULT;
 
-                out->uid        = tbuf_old.sem_perm.uid;
-                out->gid        = tbuf_old.sem_perm.gid;
-                out->mode       = tbuf_old.sem_perm.mode;
+                out->sem_perm.uid       = tbuf_old.sem_perm.uid;
+                out->sem_perm.gid       = tbuf_old.sem_perm.gid;
+                out->sem_perm.mode      = tbuf_old.sem_perm.mode;
 
                 return 0;
             }
@@ -885,11 +871,11 @@ static int semctl_down(struct ipc_namespace *ns, int semid,
 {
         struct sem_array *sma;
         int err;
-        struct sem_setbuf uninitialized_var(setbuf);
+        struct semid64_ds semid64;
         struct kern_ipc_perm *ipcp;
 
         if(cmd == IPC_SET) {
-                if(copy_semid_from_user (&setbuf, arg.buf, version))
+                if (copy_semid_from_user(&semid64, arg.buf, version))
                         return -EFAULT;
         }
         down_write(&sem_ids(ns).rw_mutex);
@@ -906,7 +892,9 @@ static int semctl_down(struct ipc_namespace *ns, int semid,
                 goto out_unlock;