* 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.
+ * using a rbtree tree.
*/
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/spinlock.h>
-#include <linux/radix-tree.h>
+#include <linux/rbtree.h>
#include "ima.h"
-RADIX_TREE(ima_iint_store, GFP_ATOMIC);
-DEFINE_SPINLOCK(ima_iint_lock);
+static struct rb_root ima_iint_tree = RB_ROOT;
+static DEFINE_SPINLOCK(ima_iint_lock);
static struct kmem_cache *iint_cache __read_mostly;
int iint_initialized = 0;
-/* 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.
+/*
+ * __ima_iint_find - return the iint associated with an inode
*/
-struct ima_iint_cache *ima_iint_find_get(struct inode *inode)
+static struct ima_iint_cache *__ima_iint_find(struct inode *inode)
{
struct ima_iint_cache *iint;
+ struct rb_node *n = ima_iint_tree.rb_node;
+
+ assert_spin_locked(&ima_iint_lock);
+
+ while (n) {
+ iint = rb_entry(n, struct ima_iint_cache, rb_node);
+
+ if (inode < iint->inode)
+ n = n->rb_left;
+ else if (inode > iint->inode)
+ n = n->rb_right;
+ else
+ break;
+ }
+ if (!n)
+ return NULL;
- 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;
}
-/**
- * ima_inode_alloc - allocate an iint associated with an inode
- * @inode: pointer to the inode
+/*
+ * ima_iint_find - return the iint associated with an inode
*/
-int ima_inode_alloc(struct inode *inode)
+struct ima_iint_cache *ima_iint_find(struct inode *inode)
{
- struct ima_iint_cache *iint = NULL;
- int rc = 0;
-
- iint = kmem_cache_alloc(iint_cache, GFP_NOFS);
- if (!iint)
- return -ENOMEM;
+ struct ima_iint_cache *iint;
- rc = radix_tree_preload(GFP_NOFS);
- if (rc < 0)
- goto out;
+ if (!IS_IMA(inode))
+ return NULL;
spin_lock(&ima_iint_lock);
- rc = radix_tree_insert(&ima_iint_store, (unsigned long)inode, iint);
+ iint = __ima_iint_find(inode);
spin_unlock(&ima_iint_lock);
- radix_tree_preload_end();
-out:
- if (rc < 0)
- kmem_cache_free(iint_cache, iint);
- return rc;
+ return iint;
}
-/* iint_free - called when the iint refcount goes to zero */
-void iint_free(struct kref *kref)
+static void iint_free(struct ima_iint_cache *iint)
{
- 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", __func__,
- iint->readcount);
- iint->readcount = 0;
- }
- if (iint->writecount != 0) {
- printk(KERN_INFO "%s: writecount: %ld\n", __func__,
- iint->writecount);
- iint->writecount = 0;
- }
- if (iint->opencount != 0) {
- printk(KERN_INFO "%s: opencount: %ld\n", __func__,
- iint->opencount);
- iint->opencount = 0;
- }
- kref_init(&iint->refcount);
kmem_cache_free(iint_cache, iint);
}
-void iint_rcu_free(struct rcu_head *rcu_head)
+/**
+ * ima_inode_alloc - allocate an iint associated with an inode
+ * @inode: pointer to the inode
+ */
+int ima_inode_alloc(struct inode *inode)
{
- struct ima_iint_cache *iint = container_of(rcu_head,
- struct ima_iint_cache, rcu);
- kref_put(&iint->refcount, iint_free);
+ struct rb_node **p;
+ struct rb_node *new_node, *parent = NULL;
+ struct ima_iint_cache *new_iint, *test_iint;
+ int rc;
+
+ new_iint = kmem_cache_alloc(iint_cache, GFP_NOFS);
+ if (!new_iint)
+ return -ENOMEM;
+
+ new_iint->inode = inode;
+ new_node = &new_iint->rb_node;
+
+ mutex_lock(&inode->i_mutex); /* i_flags */
+ spin_lock(&ima_iint_lock);
+
+ p = &ima_iint_tree.rb_node;
+ while (*p) {
+ parent = *p;
+ test_iint = rb_entry(parent, struct ima_iint_cache, rb_node);
+
+ rc = -EEXIST;
+ if (inode < test_iint->inode)
+ p = &(*p)->rb_left;
+ else if (inode > test_iint->inode)
+ p = &(*p)->rb_right;
+ else
+ goto out_err;
+ }
+
+ inode->i_flags |= S_IMA;
+ rb_link_node(new_node, parent, p);
+ rb_insert_color(new_node, &ima_iint_tree);
+
+ spin_unlock(&ima_iint_lock);
+ mutex_unlock(&inode->i_mutex); /* i_flags */
+
+ return 0;
+out_err:
+ spin_unlock(&ima_iint_lock);
+ mutex_unlock(&inode->i_mutex); /* i_flags */
+ iint_free(new_iint);
+
+ return rc;
}
/**
{
struct ima_iint_cache *iint;
+ if (inode->i_readcount)
+ printk(KERN_INFO "%s: readcount: %u\n", __func__, inode->i_readcount);
+
+ inode->i_readcount = 0;
+
+ if (!IS_IMA(inode))
+ return;
+
spin_lock(&ima_iint_lock);
- iint = radix_tree_delete(&ima_iint_store, (unsigned long)inode);
+ iint = __ima_iint_find(inode);
+ rb_erase(&iint->rb_node, &ima_iint_tree);
spin_unlock(&ima_iint_lock);
- if (iint)
- call_rcu(&iint->rcu, iint_rcu_free);
+
+ iint_free(iint);
}
static void init_once(void *foo)
iint->version = 0;
iint->flags = 0UL;
mutex_init(&iint->mutex);
- iint->readcount = 0;
- iint->writecount = 0;
- iint->opencount = 0;
- kref_init(&iint->refcount);
}
static int __init ima_iintcache_init(void)
git://bbs.cooldavid.org / net-next-2.6.git / blobdiff