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https://github.com/torvalds/linux
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54bb6552bd
ima wants to create an inode information struct (iint) when inodes are allocated. This means that at least the part of ima which does this allocation (the allocation is filled with information later) should before any inodes are created. To accomplish this we split the ima initialization routine placing the kmem cache allocator inside a security_initcall() function. Since this makes use of radix trees we also need to make sure that is initialized before security_initcall(). Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
147 lines
3.4 KiB
C
147 lines
3.4 KiB
C
/*
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* Copyright (C) 2008 IBM Corporation
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*
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* Authors:
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* Mimi Zohar <zohar@us.ibm.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation, version 2 of the
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* License.
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*
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* File: ima_iint.c
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* - implements the IMA hooks: ima_inode_alloc, ima_inode_free
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* - cache integrity information associated with an inode
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* using a radix tree.
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*/
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#include <linux/module.h>
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#include <linux/spinlock.h>
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#include <linux/radix-tree.h>
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#include "ima.h"
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RADIX_TREE(ima_iint_store, GFP_ATOMIC);
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DEFINE_SPINLOCK(ima_iint_lock);
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static struct kmem_cache *iint_cache __read_mostly;
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/* ima_iint_find_get - return the iint associated with an inode
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*
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* ima_iint_find_get gets a reference to the iint. Caller must
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* remember to put the iint reference.
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*/
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struct ima_iint_cache *ima_iint_find_get(struct inode *inode)
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{
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struct ima_iint_cache *iint;
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rcu_read_lock();
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iint = radix_tree_lookup(&ima_iint_store, (unsigned long)inode);
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if (!iint)
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goto out;
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kref_get(&iint->refcount);
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out:
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rcu_read_unlock();
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return iint;
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}
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/**
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* ima_inode_alloc - allocate an iint associated with an inode
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* @inode: pointer to the inode
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*/
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int ima_inode_alloc(struct inode *inode)
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{
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struct ima_iint_cache *iint = NULL;
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int rc = 0;
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iint = kmem_cache_alloc(iint_cache, GFP_NOFS);
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if (!iint)
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return -ENOMEM;
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rc = radix_tree_preload(GFP_NOFS);
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if (rc < 0)
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goto out;
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spin_lock(&ima_iint_lock);
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rc = radix_tree_insert(&ima_iint_store, (unsigned long)inode, iint);
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spin_unlock(&ima_iint_lock);
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out:
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if (rc < 0)
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kmem_cache_free(iint_cache, iint);
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radix_tree_preload_end();
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return rc;
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}
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/* iint_free - called when the iint refcount goes to zero */
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void iint_free(struct kref *kref)
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{
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struct ima_iint_cache *iint = container_of(kref, struct ima_iint_cache,
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refcount);
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iint->version = 0;
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iint->flags = 0UL;
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if (iint->readcount != 0) {
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printk(KERN_INFO "%s: readcount: %ld\n", __FUNCTION__,
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iint->readcount);
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iint->readcount = 0;
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}
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if (iint->writecount != 0) {
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printk(KERN_INFO "%s: writecount: %ld\n", __FUNCTION__,
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iint->writecount);
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iint->writecount = 0;
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}
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if (iint->opencount != 0) {
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printk(KERN_INFO "%s: opencount: %ld\n", __FUNCTION__,
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iint->opencount);
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iint->opencount = 0;
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}
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kref_set(&iint->refcount, 1);
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kmem_cache_free(iint_cache, iint);
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}
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void iint_rcu_free(struct rcu_head *rcu_head)
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{
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struct ima_iint_cache *iint = container_of(rcu_head,
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struct ima_iint_cache, rcu);
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kref_put(&iint->refcount, iint_free);
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}
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/**
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* ima_inode_free - called on security_inode_free
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* @inode: pointer to the inode
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*
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* Free the integrity information(iint) associated with an inode.
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*/
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void ima_inode_free(struct inode *inode)
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{
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struct ima_iint_cache *iint;
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spin_lock(&ima_iint_lock);
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iint = radix_tree_delete(&ima_iint_store, (unsigned long)inode);
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spin_unlock(&ima_iint_lock);
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if (iint)
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call_rcu(&iint->rcu, iint_rcu_free);
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}
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static void init_once(void *foo)
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{
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struct ima_iint_cache *iint = foo;
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memset(iint, 0, sizeof *iint);
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iint->version = 0;
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iint->flags = 0UL;
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mutex_init(&iint->mutex);
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iint->readcount = 0;
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iint->writecount = 0;
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iint->opencount = 0;
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kref_set(&iint->refcount, 1);
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}
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static int __init ima_iintcache_init(void)
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{
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iint_cache =
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kmem_cache_create("iint_cache", sizeof(struct ima_iint_cache), 0,
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SLAB_PANIC, init_once);
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return 0;
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}
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security_initcall(ima_iintcache_init);
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