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;
62 spin_lock(&ima_iint_lock);
63 iint = __ima_iint_find(inode);
64 spin_unlock(&ima_iint_lock);
69 static void iint_free(struct ima_iint_cache *iint)
73 kmem_cache_free(iint_cache, iint);
77 * ima_inode_alloc - allocate an iint associated with an inode
78 * @inode: pointer to the inode
80 int ima_inode_alloc(struct inode *inode)
83 struct rb_node *new_node, *parent = NULL;
84 struct ima_iint_cache *new_iint, *test_iint;
87 new_iint = kmem_cache_alloc(iint_cache, GFP_NOFS);
91 new_iint->inode = inode;
92 new_node = &new_iint->rb_node;
94 spin_lock(&ima_iint_lock);
96 p = &ima_iint_tree.rb_node;
99 test_iint = rb_entry(parent, struct ima_iint_cache, rb_node);
102 if (inode < test_iint->inode)
104 else if (inode > test_iint->inode)
110 rb_link_node(new_node, parent, p);
111 rb_insert_color(new_node, &ima_iint_tree);
113 spin_unlock(&ima_iint_lock);
117 spin_unlock(&ima_iint_lock);
124 * ima_inode_free - called on security_inode_free
125 * @inode: pointer to the inode
127 * Free the integrity information(iint) associated with an inode.
129 void ima_inode_free(struct inode *inode)
131 struct ima_iint_cache *iint;
133 if (inode->i_readcount)
134 printk(KERN_INFO "%s: readcount: %u\n", __func__, inode->i_readcount);
136 inode->i_readcount = 0;
138 spin_lock(&ima_iint_lock);
139 iint = __ima_iint_find(inode);
141 rb_erase(&iint->rb_node, &ima_iint_tree);
142 spin_unlock(&ima_iint_lock);
150 static void init_once(void *foo)
152 struct ima_iint_cache *iint = foo;
154 memset(iint, 0, sizeof *iint);
157 mutex_init(&iint->mutex);
160 static int __init ima_iintcache_init(void)
163 kmem_cache_create("iint_cache", sizeof(struct ima_iint_cache), 0,
164 SLAB_PANIC, init_once);
165 iint_initialized = 1;
168 security_initcall(ima_iintcache_init);