diff -Naurp linux-2.6.0-test9-mm4.orig/fs/proc/generic.c linux-2.6.0-test9-mm4.new/fs/proc/generic.c
--- linux-2.6.0-test9-mm4.orig/fs/proc/generic.c	2003-10-25 13:44:56.000000000 -0500
+++ linux-2.6.0-test9-mm4.new/fs/proc/generic.c	2003-11-21 14:47:00.000000000 -0600
@@ -260,6 +260,7 @@ static int xlate_proc_name(const char *n
 	int			len;
 
 	de = &proc_root;
+	lock_kernel();
 	while (1) {
 		next = strchr(cp, '/');
 		if (!next)
@@ -270,10 +271,13 @@ static int xlate_proc_name(const char *n
 			if (proc_match(len, cp, de))
 				break;
 		}
-		if (!de)
+		if (!de) {
+			unlock_kernel();
 			return -ENOENT;
+		}
 		cp += len + 1;
 	}
+	unlock_kernel();
 	*residual = cp;
 	*ret = de;
 	return 0;
@@ -462,6 +466,7 @@ static int proc_register(struct proc_dir
 	if (i < 0)
 		return -EAGAIN;
 	dp->low_ino = i;
+	lock_kernel(); /* needed to protect against concurrent registration */
 	dp->next = dir->subdir;
 	dp->parent = dir;
 	dir->subdir = dp;
@@ -480,6 +485,7 @@ static int proc_register(struct proc_dir
 		if (dp->proc_iops == NULL)
 			dp->proc_iops = &proc_file_inode_operations;
 	}
+	unlock_kernel();
 	return 0;
 }
 
@@ -507,7 +513,6 @@ static void proc_kill_inodes(struct proc
 		if (PDE(inode) != de)
 			continue;
 		fops = filp->f_op;
-		filp->f_op = NULL;
 		fops_put(fops);
 	}
 	file_list_unlock();
@@ -643,6 +648,7 @@ void remove_proc_entry(const char *name,
 	if (!parent && xlate_proc_name(name, &parent, &fn) != 0)
 		goto out;
 	len = strlen(fn);
+	lock_kernel();
 	for (p = &parent->subdir; *p; p=&(*p)->next ) {
 		if (!proc_match(len, fn, *p))
 			continue;
@@ -664,6 +670,7 @@ void remove_proc_entry(const char *name,
 		}
 		break;
 	}
+	unlock_kernel();
 out:
 	return;
 }