[PATCH 2.6.24-rc3-mm1 2/3] IPC/semaphores: consolidate SEM_STAT and IPC_STAT commands

[pierre.peiffer@bull.net]

[-- Attachment #1: ipc_sem_consolidate_stat_cmd.patch --]
[-- Type: text/plain, Size: 2898 bytes --]

From: Pierre Peiffer <pierre.peiffer@bull.net>

These both 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 semctl_nolock(). It also removes one unused parameter for
this function.

Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net>
---

 ipc/sem.c |   38 ++++++++++++++++----------------------
 1 file changed, 16 insertions(+), 22 deletions(-)

Index: b/ipc/sem.c
===================================================================
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -599,8 +599,8 @@ static unsigned long copy_semid_to_user(
 	}
 }
 
-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;
@@ -639,14 +639,23 @@ static int semctl_nolock(struct ipc_name
 			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))
@@ -656,8 +665,6 @@ static int semctl_nolock(struct ipc_name
 		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);
@@ -792,19 +799,6 @@ static int semctl_main(struct ipc_namesp
 		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;
@@ -971,15 +965,15 @@ asmlinkage long sys_semctl (int semid, i
 	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);

-- 
Pierre Peiffer