diff -uNr 99-pre2.3/Documentation/Changes c2-3/Documentation/Changes
--- 99-pre2.3/Documentation/Changes	Fri Mar 17 09:40:08 2000
+++ c2-3/Documentation/Changes	Fri Mar 17 20:06:28 2000
@@ -73,8 +73,7 @@
 ===================
 
    To use System V shared memory, you have to mount the shm filesystem
-somewhere and put the mountpoint into /proc/sys/kernel/shmpath.
-Default is /var/shm.
+somewhere.
 
    <CTRL><ALT><DEL> now performs a cold reboot instead of a warm reboot
 for increased hardware compatibility.  If you want a warm reboot and
diff -uNr 99-pre2.3/ipc/shm.c c2-3/ipc/shm.c
--- 99-pre2.3/ipc/shm.c	Fri Mar 17 09:40:09 2000
+++ c2-3/ipc/shm.c	Fri Mar 17 20:04:48 2000
@@ -20,6 +20,13 @@
  *    can only be mounted one time.
  * 3) Read and write are not implemented (should they?)
  * 4) No special nodes are supported
+ *
+ * There are the following mount options:
+ * - nr_blocks (^= shmall) is the number of blocks of size PAGE_SIZE
+ *   we are allowed to allocate
+ * - nr_inodes (^= shmmni) is the number of files we are allowed to
+ *   allocate
+ * - mode is the mode for the root directory (default S_IRWXUGO | S_ISVTX)
  */
 
 #include <linux/config.h>
@@ -74,6 +81,7 @@
 			time_t			ctime;
 			pid_t			cpid;
 			pid_t			lpid;
+			int			unlinked;
 			int			nlen;
 			char			nm[0];
 		} shmem;
@@ -91,6 +99,7 @@
 #define shm_lprid	permap.shmem.lpid
 #define shm_namelen	permap.shmem.nlen
 #define shm_name	permap.shmem.nm
+#define shm_unlinked	permap.shmem.unlinked
 #define zsem		permap.zero.sema
 #define zero_list	permap.zero.list
 
@@ -111,6 +120,7 @@
 static void killseg_core(struct shmid_kernel *shp, int doacc);
 static void shm_open (struct vm_area_struct *shmd);
 static void shm_close (struct vm_area_struct *shmd);
+static void shm_remove_name(struct shmid_kernel *shp, int id);
 static struct page * shm_nopage(struct vm_area_struct *, unsigned long, int);
 static int shm_swapout(struct page *, struct file *);
 #ifdef CONFIG_PROC_FS
@@ -435,7 +445,7 @@
 				continue;
 			if (!(shp = shm_get (nr-2))) 
 				continue;
-			if (shp->shm_perm.mode & SHM_DEST)
+			if (shp->shm_unlinked)
 				continue;
 			if (filldir(dirent, shp->shm_name, shp->shm_namelen, nr, nr) < 0 )
 				break;;
@@ -464,7 +474,7 @@
 			continue;
 		if (!(shp = shm_lock(i)))
 			continue;
-		if (!(shp->shm_perm.mode & SHM_DEST) &&
+		if (!(shp->shm_unlinked) &&
 		    dent->d_name.len == shp->shm_namelen &&
 		    strncmp(dent->d_name.name, shp->shm_name, shp->shm_namelen) == 0)
 			goto found;
@@ -502,6 +512,7 @@
 	down (&shm_ids.sem);
 	if (!(shp = shm_lock (inode->i_ino)))
 		BUG();
+	shp->shm_unlinked = 1;
 	shp->shm_perm.mode |= SHM_DEST;
 	shp->shm_perm.key = IPC_PRIVATE; /* Do not find it any more */
 	shm_unlock (inode->i_ino);
@@ -633,16 +644,18 @@
 static inline struct shmid_kernel *newseg_alloc(int numpages, size_t namelen)
 {
 	struct shmid_kernel *shp;
+	pte_t		   **dir;
 
 	shp = (struct shmid_kernel *) kmalloc (sizeof (*shp) + namelen, GFP_KERNEL);
 	if (!shp)
-		return 0;
+		return ERR_PTR(-ENOMEM);
 
-	shp->shm_dir = shm_alloc (numpages);
-	if (!shp->shm_dir) {
+	dir = shm_alloc (numpages);
+	if (IS_ERR(dir)) {
 		kfree(shp);
-		return 0;
+		return ERR_PTR(PTR_ERR(dir));
 	}
+	shp->shm_dir    = dir;
 	shp->shm_npages = numpages;
 	shp->shm_nattch = 0;
 	shp->shm_namelen = namelen;
@@ -664,8 +677,8 @@
 	if (shm_tot + numpages >= shm_ctlall)
 		return -ENOSPC;
 
-	if (!(shp = newseg_alloc(numpages, namelen ? namelen : SHM_FMT_LEN + 1)))
-		return -ENOMEM;
+	if (IS_ERR(shp = newseg_alloc(numpages, namelen ? namelen : SHM_FMT_LEN + 1)))
+		return PTR_ERR(shp);
 	id = ipc_addid(&shm_ids, &shp->shm_perm, shm_ctlmni+1);
 	if(id == -1) {
 		shm_free(shp->shm_dir,numpages);
@@ -680,6 +693,7 @@
 	shp->shm_atim = shp->shm_dtim = 0;
 	shp->shm_ctim = CURRENT_TIME;
 	shp->id = shm_buildid(id,shp->shm_perm.seq);
+	shp->shm_unlinked = 0;
 	if (namelen != 0) {
 		shp->shm_namelen = namelen;
 		memcpy (shp->shm_name, name, namelen);		  
@@ -1002,16 +1016,30 @@
 	}
 	case IPC_RMID:
 	{
-		char name[SHM_FMT_LEN+1];
-		if ((shmid % SEQ_MULTIPLIER)== zero_id)
-			return -EINVAL;
-		sprintf (name, SHM_FMT, shmid);
+		/*
+		 * A shmat() on an RMID segment is legal in older
+		 * Linux and if we change it apps break...
+		 *
+		 * Instead we set a destroyed flag, and then blow the
+		 * name away when the usage hits zero.
+		 */
+
 		lock_kernel();
-		err = do_unlink (name, dget(shm_sb->s_root));
+		if ((shmid % SEQ_MULTIPLIER) == zero_id)
+			return -EINVAL;
+		shp = shm_lock(shmid);
+		if(shp==NULL)
+			return -EINVAL;
+		if(shm_checkid(shp,shmid)!=0) {
+			shm_unlock(shmid);
+			return -EIDRM;
+		}
+
+		shp->shm_perm.mode |= SHM_DEST;
+		shp->shm_perm.key = IPC_PRIVATE; /* Do not find it any more */
+		shm_remove_name (shp, shmid);
 		unlock_kernel();
-		if (err == -ENOENT)
-			err = -EINVAL;
-		return err;
+		return 0;
 	}
 
 	case IPC_SET:
@@ -1109,10 +1137,8 @@
 	sprintf (name, SHM_FMT, shmid); 
 	lock_kernel();
 	file = filp_open(name, O_RDWR, 0, dget(shm_sb->s_root));
-	if (IS_ERR (file)) {
-		unlock_kernel();
+	if (IS_ERR (file))
 		goto bad_file;
-	}
 	*raddr = do_mmap (file, addr, file->f_dentry->d_inode->i_size,
 			  (shmflg & SHM_RDONLY ? PROT_READ :
 			   PROT_READ | PROT_WRITE), flags, 0);
@@ -1125,6 +1151,7 @@
 	return err;
 
 bad_file:
+	unlock_kernel();
 	if ((err = PTR_ERR(file)) == -ENOENT)
 		return -EINVAL;
 	return err;
@@ -1137,6 +1164,24 @@
 }
 
 /*
+ * Remove a name. Must be called with lock_kernel and the shmid
+ * locked. Will unlock the shmid.
+ */
+ 
+static void shm_remove_name(struct shmid_kernel *shp, int id)
+{
+	char name[SHM_FMT_LEN+1];
+
+	if(!(shp->shm_nattch == 0 && shp->shm_perm.mode & SHM_DEST)) {
+		shm_unlock(id);
+		return;
+	}
+	sprintf (name, SHM_FMT, id);
+	shm_unlock(id);
+	do_unlink (name, dget(shm_sb->s_root));
+}
+
+/*
  * remove the attach descriptor shmd.
  * free memory for segment if it is marked destroyed.
  * The descriptor has already been removed from the current->mm->mmap list
@@ -1147,13 +1192,15 @@
 	int id = shmd->vm_file->f_dentry->d_inode->i_ino;
 	struct shmid_kernel *shp;
 
+	lock_kernel();
 	/* remove from the list of attaches of the shm segment */
 	if(!(shp = shm_lock(id)))
 		BUG();
 	shp->shm_lprid = current->pid;
 	shp->shm_dtim = CURRENT_TIME;
 	shp->shm_nattch--;
-	shm_unlock(id);
+	shm_remove_name(shp, id);
+	unlock_kernel();
 }
 
 /*
@@ -1458,8 +1505,8 @@
 			continue;
 		shp = shm_lock(i);
 		if(shp!=NULL) {
-#define SMALL_STRING "%10d %10d  %4o %10u %5u %5u  %5d %5u %5u %5u %5u %10lu %10lu %10lu %.*s\n"
-#define BIG_STRING   "%10d %10d  %4o %21u %5u %5u  %5d %5u %5u %5u %5u %10lu %10lu %10lu %.*s\n"
+#define SMALL_STRING "%10d %10d  %4o %10u %5u %5u  %5d %5u %5u %5u %5u %10lu %10lu %10lu %.*s%s\n"
+#define BIG_STRING   "%10d %10d  %4o %21u %5u %5u  %5d %5u %5u %5u %5u %10lu %10lu %10lu %.*s%s\n"
 			char *format;
 
 			if (sizeof(size_t) <= sizeof(int))
@@ -1482,7 +1529,8 @@
 				shp->shm_dtim,
 				shp->shm_ctim,
 				shp->shm_namelen,
-				shp->shm_name);
+				shp->shm_name,
+				shp->shm_unlinked ? " (deleted)" : "");
 			shm_unlock(i);
 
 			pos += len;
@@ -1571,8 +1619,8 @@
 
 	if (!vm_enough_memory((vma->vm_end - vma->vm_start) >> PAGE_SHIFT))
 		return -ENOMEM;
-	if (!(shp = newseg_alloc((vma->vm_end - vma->vm_start) / PAGE_SIZE, 0)))
-		return -ENOMEM;
+	if (IS_ERR(shp = newseg_alloc((vma->vm_end - vma->vm_start) / PAGE_SIZE, 0)))
+		return PTR_ERR(shp);
 	if ((filp = file_setup(vma->vm_file, shp)) == 0) {
 		killseg_core(shp, 0);
 		return -ENOMEM;