Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

1 files changed, 204 insertions, 0 deletions

diff --git a/security/integrity/ima/ima_iint.c b/security/integrity/ima/ima_iint.c
new file mode 100644
index 000000000000..ec79f1ee992c
--- /dev/null
+++ b/security/integrity/ima/ima_iint.c
@@ -0,0 +1,204 @@
+/*
+ * Copyright (C) 2008 IBM Corporation
+ *
+ * Authors:
+ * Mimi Zohar <zohar@us.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, version 2 of the
+ * License.
+ *
+ * File: ima_iint.c
+ * 	- implements the IMA hooks: ima_inode_alloc, ima_inode_free
+ *	- cache integrity information associated with an inode
+ *	  using a radix tree.
+ */
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/radix-tree.h>
+#include "ima.h"
+
+#define ima_iint_delete ima_inode_free
+
+RADIX_TREE(ima_iint_store, GFP_ATOMIC);
+DEFINE_SPINLOCK(ima_iint_lock);
+
+static struct kmem_cache *iint_cache __read_mostly;
+
+/* ima_iint_find_get - return the iint associated with an inode
+ *
+ * ima_iint_find_get gets a reference to the iint. Caller must
+ * remember to put the iint reference.
+ */
+struct ima_iint_cache *ima_iint_find_get(struct inode *inode)
+{
+	struct ima_iint_cache *iint;
+
+	rcu_read_lock();
+	iint = radix_tree_lookup(&ima_iint_store, (unsigned long)inode);
+	if (!iint)
+		goto out;
+	kref_get(&iint->refcount);
+out:
+	rcu_read_unlock();
+	return iint;
+}
+
+/* Allocate memory for the iint associated with the inode
+ * from the iint_cache slab, initialize the iint, and
+ * insert it into the radix tree.
+ *
+ * On success return a pointer to the iint; on failure return NULL.
+ */
+struct ima_iint_cache *ima_iint_insert(struct inode *inode)
+{
+	struct ima_iint_cache *iint = NULL;
+	int rc = 0;
+
+	if (!ima_initialized)
+		return iint;
+	iint = kmem_cache_alloc(iint_cache, GFP_KERNEL);
+	if (!iint)
+		return iint;
+
+	rc = radix_tree_preload(GFP_KERNEL);
+	if (rc < 0)
+		goto out;
+
+	spin_lock(&ima_iint_lock);
+	rc = radix_tree_insert(&ima_iint_store, (unsigned long)inode, iint);
+	spin_unlock(&ima_iint_lock);
+out:
+	if (rc < 0) {
+		kmem_cache_free(iint_cache, iint);
+		if (rc == -EEXIST) {
+			spin_lock(&ima_iint_lock);
+			iint = radix_tree_lookup(&ima_iint_store,
+						 (unsigned long)inode);
+			spin_unlock(&ima_iint_lock);
+		} else
+			iint = NULL;
+	}
+	radix_tree_preload_end();
+	return iint;
+}
+
+/**
+ * ima_inode_alloc - allocate an iint associated with an inode
+ * @inode: pointer to the inode
+ *
+ * Return 0 on success, 1 on failure.
+ */
+int ima_inode_alloc(struct inode *inode)
+{
+	struct ima_iint_cache *iint;
+
+	if (!ima_initialized)
+		return 0;
+
+	iint = ima_iint_insert(inode);
+	if (!iint)
+		return 1;
+	return 0;
+}
+
+/* ima_iint_find_insert_get - get the iint associated with an inode
+ *
+ * Most insertions are done at inode_alloc, except those allocated
+ * before late_initcall. When the iint does not exist, allocate it,
+ * initialize and insert it, and increment the iint refcount.
+ *
+ * (Can't initialize at security_initcall before any inodes are
+ * allocated, got to wait at least until proc_init.)
+ *
+ *  Return the iint.
+ */
+struct ima_iint_cache *ima_iint_find_insert_get(struct inode *inode)
+{
+	struct ima_iint_cache *iint = NULL;
+
+	iint = ima_iint_find_get(inode);
+	if (iint)
+		return iint;
+
+	iint = ima_iint_insert(inode);
+	if (iint)
+		kref_get(&iint->refcount);
+
+	return iint;
+}
+EXPORT_SYMBOL_GPL(ima_iint_find_insert_get);
+
+/* iint_free - called when the iint refcount goes to zero */
+void iint_free(struct kref *kref)
+{
+	struct ima_iint_cache *iint = container_of(kref, struct ima_iint_cache,
+						   refcount);
+	iint->version = 0;
+	iint->flags = 0UL;
+	if (iint->readcount != 0) {
+		printk(KERN_INFO "%s: readcount: %ld\n", __FUNCTION__,
+		       iint->readcount);
+		iint->readcount = 0;
+	}
+	if (iint->writecount != 0) {
+		printk(KERN_INFO "%s: writecount: %ld\n", __FUNCTION__,
+		       iint->writecount);
+		iint->writecount = 0;
+	}
+	if (iint->opencount != 0) {
+		printk(KERN_INFO "%s: opencount: %ld\n", __FUNCTION__,
+		       iint->opencount);
+		iint->opencount = 0;
+	}
+	kref_set(&iint->refcount, 1);
+	kmem_cache_free(iint_cache, iint);
+}
+
+void iint_rcu_free(struct rcu_head *rcu_head)
+{
+	struct ima_iint_cache *iint = container_of(rcu_head,
+						   struct ima_iint_cache, rcu);
+	kref_put(&iint->refcount, iint_free);
+}
+
+/**
+ * ima_iint_delete - called on integrity_inode_free
+ * @inode: pointer to the inode
+ *
+ * Free the integrity information(iint) associated with an inode.
+ */
+void ima_iint_delete(struct inode *inode)
+{
+	struct ima_iint_cache *iint;
+
+	if (!ima_initialized)
+		return;
+	spin_lock(&ima_iint_lock);
+	iint = radix_tree_delete(&ima_iint_store, (unsigned long)inode);
+	spin_unlock(&ima_iint_lock);
+	if (iint)
+		call_rcu(&iint->rcu, iint_rcu_free);
+}
+
+static void init_once(void *foo)
+{
+	struct ima_iint_cache *iint = foo;
+
+	memset(iint, 0, sizeof *iint);
+	iint->version = 0;
+	iint->flags = 0UL;
+	mutex_init(&iint->mutex);
+	iint->readcount = 0;
+	iint->writecount = 0;
+	iint->opencount = 0;
+	kref_set(&iint->refcount, 1);
+}
+
+void ima_iintcache_init(void)
+{
+	iint_cache =
+	    kmem_cache_create("iint_cache", sizeof(struct ima_iint_cache), 0,
+			      SLAB_PANIC, init_once);
+}