2 * Copyright (C) 2008 IBM Corporation
5 * Mimi Zohar <zohar@us.ibm.com>
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License as
9 * published by the Free Software Foundation, version 2 of the
13 * - implements the IMA hooks: ima_inode_alloc, ima_inode_free
14 * - cache integrity information associated with an inode
15 * using a rbtree tree.
17 #include <linux/slab.h>
18 #include <linux/module.h>
19 #include <linux/spinlock.h>
20 #include <linux/rbtree.h>
23 static struct rb_root ima_iint_tree = RB_ROOT;
24 static DEFINE_SPINLOCK(ima_iint_lock);
25 static struct kmem_cache *iint_cache __read_mostly;
27 int iint_initialized = 0;
30 * __ima_iint_find - return the iint associated with an inode
32 static struct ima_iint_cache *__ima_iint_find(struct inode *inode)
34 struct ima_iint_cache *iint;
35 struct rb_node *n = ima_iint_tree.rb_node;
37 assert_spin_locked(&ima_iint_lock);
40 iint = rb_entry(n, struct ima_iint_cache, rb_node);
42 if (inode < iint->inode)
44 else if (inode > iint->inode)
56 * ima_iint_find - return the iint associated with an inode
58 struct ima_iint_cache *ima_iint_find(struct inode *inode)
60 struct ima_iint_cache *iint;
65 spin_lock(&ima_iint_lock);
66 iint = __ima_iint_find(inode);
67 spin_unlock(&ima_iint_lock);
72 static void iint_free(struct ima_iint_cache *iint)
76 kmem_cache_free(iint_cache, iint);
80 * ima_inode_alloc - allocate an iint associated with an inode
81 * @inode: pointer to the inode
83 int ima_inode_alloc(struct inode *inode)
86 struct rb_node *new_node, *parent = NULL;
87 struct ima_iint_cache *new_iint, *test_iint;
90 new_iint = kmem_cache_alloc(iint_cache, GFP_NOFS);
94 new_iint->inode = inode;
95 new_node = &new_iint->rb_node;
97 mutex_lock(&inode->i_mutex); /* i_flags */
98 spin_lock(&ima_iint_lock);
100 p = &ima_iint_tree.rb_node;
103 test_iint = rb_entry(parent, struct ima_iint_cache, rb_node);
106 if (inode < test_iint->inode)
108 else if (inode > test_iint->inode)
114 inode->i_flags |= S_IMA;
115 rb_link_node(new_node, parent, p);
116 rb_insert_color(new_node, &ima_iint_tree);
118 spin_unlock(&ima_iint_lock);
119 mutex_unlock(&inode->i_mutex); /* i_flags */
123 spin_unlock(&ima_iint_lock);
124 mutex_unlock(&inode->i_mutex); /* i_flags */
131 * ima_inode_free - called on security_inode_free
132 * @inode: pointer to the inode
134 * Free the integrity information(iint) associated with an inode.
136 void ima_inode_free(struct inode *inode)
138 struct ima_iint_cache *iint;
143 spin_lock(&ima_iint_lock);
144 iint = __ima_iint_find(inode);
145 rb_erase(&iint->rb_node, &ima_iint_tree);
146 spin_unlock(&ima_iint_lock);
151 static void init_once(void *foo)
153 struct ima_iint_cache *iint = foo;
155 memset(iint, 0, sizeof *iint);
158 mutex_init(&iint->mutex);
161 static int __init ima_iintcache_init(void)
164 kmem_cache_create("iint_cache", sizeof(struct ima_iint_cache), 0,
165 SLAB_PANIC, init_once);
166 iint_initialized = 1;
169 security_initcall(ima_iintcache_init);