[PATCH 2.6.24-rc8-mm1 06/15] IPC: get rid of the use *_setbuf structure.

[pierre.peiffer-6ktuUTfB/bM@public.gmane.org]

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[-- Type: text/plain, Size: 8774 bytes --]

From: Pierre Peiffer <pierre.peiffer-6ktuUTfB/bM@public.gmane.org>

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

This patch get 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.
Moreover, this will simplify the code for handling the IPC_SETALL
command provided in the next patch.

Signed-off-by: Pierre Peiffer <pierre.peiffer-6ktuUTfB/bM@public.gmane.org>
Acked-by: Serge Hallyn <serue-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
---

 ipc/msg.c |   51 ++++++++++++++++++---------------------------------
 ipc/sem.c |   40 ++++++++++++++--------------------------
 ipc/shm.c |   41 ++++++++++++++---------------------------
 3 files changed, 46 insertions(+), 86 deletions(-)

Index: b/ipc/msg.c
===================================================================
--- a/ipc/msg.c
+++ b/ipc/msg.c
@@ -351,31 +351,14 @@ copy_msqid_to_user(void __user *buf, str
 	}
 }
 
-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;
@@ -383,14 +366,14 @@ copy_msqid_from_user(struct msq_setbuf *
 		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;
 	}
@@ -408,12 +391,12 @@ static int msgctl_down(struct ipc_namesp
 		       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;
 	}
 
@@ -431,8 +414,10 @@ static int msgctl_down(struct ipc_namesp
 		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;
 	}
@@ -454,18 +439,18 @@ static int msgctl_down(struct ipc_namesp
 		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.
Index: b/ipc/sem.c
===================================================================
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -837,28 +837,14 @@ 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;
@@ -866,9 +852,9 @@ static inline unsigned long copy_semid_f
 		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;
 	    }
@@ -887,11 +873,11 @@ static int semctl_down(struct ipc_namesp
 {
 	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);
@@ -908,7 +894,9 @@ static int semctl_down(struct ipc_namesp
 		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, semid64.sem_perm.uid,
+					 semid64.sem_perm.gid,
+					 semid64.sem_perm.mode);
 		if (err)
 			goto out_unlock;
 	}
@@ -927,10 +915,10 @@ static int semctl_down(struct ipc_namesp
 		freeary(ns, ipcp);
 		goto out_up;
 	case IPC_SET:
-		ipcp->uid = setbuf.uid;
-		ipcp->gid = setbuf.gid;
+		ipcp->uid = semid64.sem_perm.uid;
+		ipcp->gid = semid64.sem_perm.gid;
 		ipcp->mode = (ipcp->mode & ~S_IRWXUGO)
-				| (setbuf.mode & S_IRWXUGO);
+				| (semid64.sem_perm.mode & S_IRWXUGO);
 		sma->sem_ctime = get_seconds();
 		break;
 	default:
Index: b/ipc/shm.c
===================================================================
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -520,28 +520,14 @@ static inline unsigned long copy_shmid_t
 	}
 }
 
-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;
@@ -549,9 +535,9 @@ static inline unsigned long copy_shmid_f
 		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;
 	    }
@@ -634,12 +620,12 @@ static int shmctl_down(struct ipc_namesp
 		       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;
 	}
 
@@ -657,8 +643,9 @@ static int shmctl_down(struct ipc_namesp
 		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;
 	}
@@ -678,10 +665,10 @@ static int shmctl_down(struct ipc_namesp
 		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:

-- 
Pierre Peiffer