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
12 * File: integrity_iint.c
13 * - implements the integrity hooks: integrity_inode_alloc,
14 * integrity_inode_free
15 * - cache integrity information associated with an inode
16 * using a rbtree tree.
18 #include <linux/slab.h>
19 #include <linux/module.h>
20 #include <linux/spinlock.h>
21 #include <linux/rbtree.h>
22 #include "integrity.h"
24 static struct rb_root integrity_iint_tree = RB_ROOT;
25 static DEFINE_SPINLOCK(integrity_iint_lock);
26 static struct kmem_cache *iint_cache __read_mostly;
31 * __integrity_iint_find - return the iint associated with an inode
33 static struct integrity_iint_cache *__integrity_iint_find(struct inode *inode)
35 struct integrity_iint_cache *iint;
36 struct rb_node *n = integrity_iint_tree.rb_node;
38 assert_spin_locked(&integrity_iint_lock);
41 iint = rb_entry(n, struct integrity_iint_cache, rb_node);
43 if (inode < iint->inode)
45 else if (inode > iint->inode)
57 * integrity_iint_find - return the iint associated with an inode
59 struct integrity_iint_cache *integrity_iint_find(struct inode *inode)
61 struct integrity_iint_cache *iint;
66 spin_lock(&integrity_iint_lock);
67 iint = __integrity_iint_find(inode);
68 spin_unlock(&integrity_iint_lock);
73 static void iint_free(struct integrity_iint_cache *iint)
77 kmem_cache_free(iint_cache, iint);
81 * integrity_inode_alloc - allocate an iint associated with an inode
82 * @inode: pointer to the inode
84 int integrity_inode_alloc(struct inode *inode)
87 struct rb_node *new_node, *parent = NULL;
88 struct integrity_iint_cache *new_iint, *test_iint;
91 new_iint = kmem_cache_alloc(iint_cache, GFP_NOFS);
95 new_iint->inode = inode;
96 new_node = &new_iint->rb_node;
98 mutex_lock(&inode->i_mutex); /* i_flags */
99 spin_lock(&integrity_iint_lock);
101 p = &integrity_iint_tree.rb_node;
104 test_iint = rb_entry(parent, struct integrity_iint_cache,
107 if (inode < test_iint->inode)
109 else if (inode > test_iint->inode)
115 inode->i_flags |= S_IMA;
116 rb_link_node(new_node, parent, p);
117 rb_insert_color(new_node, &integrity_iint_tree);
119 spin_unlock(&integrity_iint_lock);
120 mutex_unlock(&inode->i_mutex); /* i_flags */
124 spin_unlock(&integrity_iint_lock);
125 mutex_unlock(&inode->i_mutex); /* i_flags */
132 * integrity_inode_free - called on security_inode_free
133 * @inode: pointer to the inode
135 * Free the integrity information(iint) associated with an inode.
137 void integrity_inode_free(struct inode *inode)
139 struct integrity_iint_cache *iint;
144 spin_lock(&integrity_iint_lock);
145 iint = __integrity_iint_find(inode);
146 rb_erase(&iint->rb_node, &integrity_iint_tree);
147 spin_unlock(&integrity_iint_lock);
152 static void init_once(void *foo)
154 struct integrity_iint_cache *iint = foo;
156 memset(iint, 0, sizeof *iint);
159 mutex_init(&iint->mutex);
160 iint->evm_status = INTEGRITY_UNKNOWN;
163 static int __init integrity_iintcache_init(void)
166 kmem_cache_create("iint_cache", sizeof(struct integrity_iint_cache),
167 0, SLAB_PANIC, init_once);
168 iint_initialized = 1;
171 security_initcall(integrity_iintcache_init);