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, 14 insertions, 27 deletions

diff --git a/ipc/shm.c b/ipc/shm.c
index 65a44bcc4ac..5e296b04bd6 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -511,28 +511,14 @@ static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_
         }
 }
 
-struct shm_setbuf {
-        uid_t   uid;
-        gid_t   gid;
-        mode_t  mode;
-};      
-
-static inline unsigned long copy_shmid_from_user(struct shm_setbuf *out, void __user *buf, int version)
+static inline unsigned long
+copy_shmid_from_user(struct shmid64_ds *out, void __user *buf, int version)
 {
         switch(version) {
         case IPC_64:
-            {
-                struct shmid64_ds tbuf;
-
-                if (copy_from_user(&tbuf, buf, sizeof(tbuf)))
+                if (copy_from_user(out, buf, sizeof(*out)))
                         return -EFAULT;
-
-                out->uid        = tbuf.shm_perm.uid;
-                out->gid        = tbuf.shm_perm.gid;
-                out->mode       = tbuf.shm_perm.mode;
-
                 return 0;
-            }
         case IPC_OLD:
             {
                 struct shmid_ds tbuf_old;
@@ -540,9 +526,9 @@ static inline unsigned long copy_shmid_from_user(struct shm_setbuf *out, void __
                 if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
                         return -EFAULT;
 
-                out->uid        = tbuf_old.shm_perm.uid;
-                out->gid        = tbuf_old.shm_perm.gid;
-                out->mode       = tbuf_old.shm_perm.mode;
+                out->shm_perm.uid       = tbuf_old.shm_perm.uid;
+                out->shm_perm.gid       = tbuf_old.shm_perm.gid;
+                out->shm_perm.mode      = tbuf_old.shm_perm.mode;
 
                 return 0;
             }
@@ -625,12 +611,12 @@ static int shmctl_down(struct ipc_namespace *ns, int shmid, int cmd,
                        struct shmid_ds __user *buf, int version)
 {
         struct kern_ipc_perm *ipcp;
-        struct shm_setbuf setbuf;
+        struct shmid64_ds shmid64;
         struct shmid_kernel *shp;
         int err;
 
         if (cmd == IPC_SET) {
-                if (copy_shmid_from_user(&setbuf, buf, version))
+                if (copy_shmid_from_user(&shmid64, buf, version))
                         return -EFAULT;
         }
 
@@ -648,8 +634,9 @@ static int shmctl_down(struct ipc_namespace *ns, int shmid, int cmd,
                 goto out_unlock;
 
         if (cmd == IPC_SET) {
-                err = audit_ipc_set_perm(0, setbuf.uid,
-                                         setbuf.gid, setbuf.mode);
+                err = audit_ipc_set_perm(0, shmid64.shm_perm.uid,
+                                         shmid64.shm_perm.gid,
+                                         shmid64.shm_perm.mode);
                 if (err)
                         goto out_unlock;
         }
@@ -669,10 +656,10 @@ static int shmctl_down(struct ipc_namespace *ns, int shmid, int cmd,
                 do_shm_rmid(ns, ipcp);
                 goto out_up;
         case IPC_SET:
-                ipcp->uid = setbuf.uid;
-                ipcp->gid = setbuf.gid;
+                ipcp->uid = shmid64.shm_perm.uid;
+                ipcp->gid = shmid64.shm_perm.gid;
                 ipcp->mode = (ipcp->mode & ~S_IRWXUGO)
-                        | (setbuf.mode & S_IRWXUGO);
+                        | (shmid64.shm_perm.mode & S_IRWXUGO);
                 shp->shm_ctim = get_seconds();
                 break;
         default: