patch-2.2.15 linux/ipc/sem.c

• Lines: 96
• Date: Fri Apr 21 12:47:01 2000
• Orig file: v2.2.14/ipc/sem.c
• Orig date: Tue Jan 4 21:19:03 2000

diff -u --new-file --recursive --exclude-from ../../exclude v2.2.14/ipc/sem.c linux/ipc/sem.c
@@ -282,7 +282,7 @@
         for (q = sma->sem_pending; q; q = q->next) {
                         
                 if (q->status == 1)
-                        return; /* wait for other process */
+			continue; /* this one was woken up before */
 
                 error = try_atomic_semop(sma, q->sops, q->nsops,
                                          q->undo, q->pid, q->alter);
@@ -521,16 +521,14 @@
 		break;
 	case IPC_SET:
 		buf = arg.buf;
-		err = copy_from_user (&tbuf, buf, sizeof (*buf));
-		if (err)
-			err = -EFAULT;
+		err = -EFAULT;
+		if(copy_from_user (&tbuf, buf, sizeof (*buf)))
+			goto out;
 		break;
 	}
 
 	err = -EIDRM;
-	if (semary[id] == IPC_UNUSED || semary[id] == IPC_NOID)
-		goto out;
-	if (sma->sem_perm.seq != (unsigned int) semid / SEMMNI)
+	if ((sma != semary[id]) || (sma->sem_perm.seq != (unsigned int) semid / SEMMNI))
 		goto out;
 
 	switch (cmd) {
@@ -540,8 +538,9 @@
 			goto out;
 		for (i = 0; i < sma->sem_nsems; i++)
 			sem_io[i] = sma->sem_base[i].semval;
+		err = -EFAULT;
 		if (copy_to_user (array, sem_io, nsems*sizeof(ushort)))
-			err = -EFAULT;
+			goto out;
 		break;
 	case SETVAL:
 		err = -EACCES;
@@ -575,8 +574,9 @@
 		tbuf.sem_otime  = sma->sem_otime;
 		tbuf.sem_ctime  = sma->sem_ctime;
 		tbuf.sem_nsems  = sma->sem_nsems;
+		err = -EFAULT;
 		if (copy_to_user (buf, &tbuf, sizeof(*buf)))
-			err = -EFAULT;
+			goto out;
 		break;
 	case SETALL:
 		err = -EACCES;
@@ -601,6 +601,25 @@
 	return err;
 }
 
+
+static struct sem_undo* freeundos(struct sem_undo* un)
+{
+	struct sem_undo* u;
+	struct sem_undo** up;
+
+	for (up = &current->semundo;(u=*up);up=&u->proc_next) {
+		if(un==u) {
+			un=u->proc_next;
+			*up=un;
+			kfree(u);
+			return un;
+		}
+	}
+	printk ("freeundos undo list error id=%d\n", un->semid);
+	return un->proc_next;
+}
+
+
 asmlinkage int sys_semop (int semid, struct sembuf *tsops, unsigned nsops)
 {
 	int id, size, error = -EINVAL;
@@ -647,9 +666,15 @@
 		/* Make sure we have an undo structure
 		 * for this process and this semaphore set.
 		 */
-		for (un = current->semundo; un; un = un->proc_next)
-			if (un->semid == semid)
+		un = current->semundo;
+		while(un != NULL) {
+			if(un->semid==semid)
 				break;
+			if(un->semid==-1)
+				un=freeundos(un);
+			else
+			un=un->proc_next;
+		}
 		if (!un) {
 			size = sizeof(struct sem_undo) + sizeof(short)*sma->sem_nsems;
 			un = (struct sem_undo *) kmalloc(size, GFP_ATOMIC);