diff -uNr 99-pre5/ipc/shm.c c5/ipc/shm.c
--- 99-pre5/ipc/shm.c	Sat Apr 15 19:14:55 2000
+++ c5/ipc/shm.c	Wed Apr 19 19:05:52 2000
@@ -1715,12 +1715,13 @@
 	d_instantiate(filp->f_dentry, inp);
 
 	/*
-	 * Copy over /dev/zero dev/ino for benefit of procfs. Use
+	 * Copy over dev/ino for benefit of procfs. Use
 	 * ino to indicate seperate mappings.
 	 */
-	filp->f_dentry->d_inode->i_dev = fzero->f_dentry->d_inode->i_dev;
+	filp->f_dentry->d_inode->i_dev = shm_sb->s_dev;
 	filp->f_dentry->d_inode->i_ino = (unsigned long)shp;
-	fput(fzero);	/* release /dev/zero file */
+	if (fzero)
+		fput(fzero);	/* release /dev/zero file */
 	return(filp);
 }
 
diff -uNr 99-pre5/mm/mmap.c c5/mm/mmap.c
--- 99-pre5/mm/mmap.c	Fri Mar 24 18:48:50 2000
+++ c5/mm/mmap.c	Wed Apr 19 19:06:09 2000
@@ -220,8 +220,7 @@
 		default:
 			return -EINVAL;
 		}
-	} else if ((flags & MAP_TYPE) != MAP_PRIVATE)
-		return -EINVAL;
+	}
 
 	/* Obtain the address to map to. we verify (or select) it and ensure
 	 * that it represents a valid section of the address space.
@@ -269,8 +268,11 @@
 			if (!(file->f_mode & FMODE_WRITE))
 				vma->vm_flags &= ~(VM_MAYWRITE | VM_SHARED);
 		}
-	} else
+	} else {
 		vma->vm_flags |= VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC;
+		if (flags & MAP_SHARED)
+			vma->vm_flags |= VM_SHARED | VM_MAYSHARE;
+	}
 	vma->vm_page_prot = protection_map[vma->vm_flags & 0x0f];
 	vma->vm_ops = NULL;
 	vma->vm_pgoff = pgoff;
@@ -316,6 +318,8 @@
 			atomic_inc(&file->f_dentry->d_inode->i_writecount);
 		if (error)
 			goto unmap_and_free_vma;
+	} else if (flags & MAP_SHARED) {
+		error = map_zero_setup (vma);
 	}
 
 	/*