1 files changed, 55 insertions, 26 deletions

diff --git a/security/inode.c b/security/inode.c
index 43382ef8896e..81fb5d6dd33e 100644
--- a/security/inode.c
+++ b/security/inode.c
@@ -22,6 +22,8 @@
 #include <linux/lsm_hooks.h>
 #include <linux/magic.h>
 
+#include "lsm.h"
+
 static struct vfsmount *mount;
 static int mount_count;
 
@@ -70,7 +72,7 @@ static struct file_system_type fs_type = {
 	.owner =	THIS_MODULE,
 	.name =		"securityfs",
 	.init_fs_context = securityfs_init_fs_context,
-	.kill_sb =	kill_litter_super,
+	.kill_sb =	kill_anon_super,
 };
 
 /**
@@ -127,24 +129,19 @@ static struct dentry *securityfs_create_dentry(const char *name, umode_t mode,
 		parent = mount->mnt_root;
 	}
 
-	dir = d_inode(parent);
-
-	inode_lock(dir);
-	dentry = lookup_noperm(&QSTR(name), parent);
-	if (IS_ERR(dentry))
+	inode = new_inode(parent->d_sb);
+	if (unlikely(!inode)) {
+		dentry = ERR_PTR(-ENOMEM);
 		goto out;
-
-	if (d_really_is_positive(dentry)) {
-		error = -EEXIST;
-		goto out1;
 	}
 
-	inode = new_inode(dir->i_sb);
-	if (!inode) {
-		error = -ENOMEM;
-		goto out1;
-	}
+	dir = d_inode(parent);
 
+	dentry = simple_start_creating(parent, name);
+	if (IS_ERR(dentry)) {
+		iput(inode);
+		goto out;
+	}
 	inode->i_ino = get_next_ino();
 	inode->i_mode = mode;
 	simple_inode_init_ts(inode);
@@ -160,15 +157,11 @@ static struct dentry *securityfs_create_dentry(const char *name, umode_t mode,
 	} else {
 		inode->i_fop = fops;
 	}
-	d_instantiate(dentry, inode);
-	inode_unlock(dir);
-	return dentry;
+	d_make_persistent(dentry, inode);
+	simple_done_creating(dentry);
+	return dentry; // borrowed
 
-out1:
-	dput(dentry);
-	dentry = ERR_PTR(error);
 out:
-	inode_unlock(dir);
 	if (pinned)
 		simple_release_fs(&mount, &mount_count);
 	return dentry;
@@ -315,12 +308,49 @@ void securityfs_remove(struct dentry *dentry)
 EXPORT_SYMBOL_GPL(securityfs_remove);
 
 #ifdef CONFIG_SECURITY
+#include <linux/spinlock.h>
+
 static struct dentry *lsm_dentry;
+
 static ssize_t lsm_read(struct file *filp, char __user *buf, size_t count,
 			loff_t *ppos)
 {
-	return simple_read_from_buffer(buf, count, ppos, lsm_names,
-		strlen(lsm_names));
+	int i;
+	static char *str;
+	static size_t len;
+	static DEFINE_SPINLOCK(lock);
+
+	/* NOTE: we never free or modify the string once it is set */
+
+	if (unlikely(!str || !len)) {
+		char *str_tmp;
+		size_t len_tmp = 0;
+
+		for (i = 0; i < lsm_active_cnt; i++)
+			/* the '+ 1' accounts for either a comma or a NUL */
+			len_tmp += strlen(lsm_idlist[i]->name) + 1;
+
+		str_tmp = kmalloc(len_tmp, GFP_KERNEL);
+		if (!str_tmp)
+			return -ENOMEM;
+		str_tmp[0] = '\0';
+
+		for (i = 0; i < lsm_active_cnt; i++) {
+			if (i > 0)
+				strcat(str_tmp, ",");
+			strcat(str_tmp, lsm_idlist[i]->name);
+		}
+
+		spin_lock(&lock);
+		if (!str) {
+			str = str_tmp;
+			len = len_tmp - 1;
+		} else
+			kfree(str_tmp);
+		spin_unlock(&lock);
+	}
+
+	return simple_read_from_buffer(buf, count, ppos, str, len);
 }
 
 static const struct file_operations lsm_ops = {
@@ -329,7 +359,7 @@ static const struct file_operations lsm_ops = {
 };
 #endif
 
-static int __init securityfs_init(void)
+int __init securityfs_init(void)
 {
 	int retval;
 
@@ -348,4 +378,3 @@ static int __init securityfs_init(void)
 #endif
 	return 0;
 }
-core_initcall(securityfs_init);