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Commit bf2276d1 authored by Dmitry Kasatkin's avatar Dmitry Kasatkin Committed by Mimi Zohar
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ima: allocating iint improvements 



With IMA-appraisal's removal of the iint mutex and taking the i_mutex
instead, allocating the iint becomes a lot simplier, as we don't need
to be concerned with two processes racing to allocate the iint. This
patch cleans up and improves performance for allocating the iint.

- removed redundant double i_mutex locking
- combined iint allocation with tree search

Changelog v2:
- removed the rwlock/read_lock changes from this patch

Signed-off-by: default avatarDmitry Kasatkin <dmitry.kasatkin@intel.com>
Signed-off-by: default avatarMimi Zohar <zohar@us.ibm.com>
parent 07f6a794

include/linux/integrity.h

+4 −3
Original line number Diff line number Diff line
@@ -22,13 +22,14 @@ enum integrity_status { 


/* List of EVM protected security xattrs */

#ifdef CONFIG_INTEGRITY

extern int integrity_inode_alloc(struct inode *inode);

extern struct integrity_iint_cache *integrity_inode_get(struct inode *inode);

extern void integrity_inode_free(struct inode *inode);



#else

static inline int integrity_inode_alloc(struct inode *inode)

static inline struct integrity_iint_cache *

				integrity_inode_get(struct inode *inode)

{

	return 0;

	return NULL;

}



static inline void integrity_inode_free(struct inode *inode)

security/integrity/iint.c

+19 −26
Original line number Diff line number Diff line
@@ -80,24 +80,26 @@ static void iint_free(struct integrity_iint_cache *iint) 
}



/**

 * integrity_inode_alloc - allocate an iint associated with an inode

 * integrity_inode_get - find or allocate an iint associated with an inode

 * @inode: pointer to the inode

 * @return: allocated iint

 *

 * Caller must lock i_mutex

 */

int integrity_inode_alloc(struct inode *inode)

struct integrity_iint_cache *integrity_inode_get(struct inode *inode)

{

	struct rb_node **p;

	struct rb_node *new_node, *parent = NULL;

	struct integrity_iint_cache *new_iint, *test_iint;

	int rc;

	struct rb_node *node, *parent = NULL;

	struct integrity_iint_cache *iint, *test_iint;



	new_iint = kmem_cache_alloc(iint_cache, GFP_NOFS);

	if (!new_iint)

		return -ENOMEM;

	iint = integrity_iint_find(inode);

	if (iint)

		return iint;



	new_iint->inode = inode;

	new_node = &new_iint->rb_node;

	iint = kmem_cache_alloc(iint_cache, GFP_NOFS);

	if (!iint)

		return NULL;



	mutex_lock(&inode->i_mutex);	/* i_flags */

	spin_lock(&integrity_iint_lock);



	p = &integrity_iint_tree.rb_node;
@@ -105,29 +107,20 @@ int integrity_inode_alloc(struct inode *inode) 
		parent = *p;

		test_iint = rb_entry(parent, struct integrity_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;

			p = &(*p)->rb_right;

	}



	iint->inode = inode;

	node = &iint->rb_node;

	inode->i_flags |= S_IMA;

	rb_link_node(new_node, parent, p);

	rb_insert_color(new_node, &integrity_iint_tree);

	rb_link_node(node, parent, p);

	rb_insert_color(node, &integrity_iint_tree);



	spin_unlock(&integrity_iint_lock);

	mutex_unlock(&inode->i_mutex);	/* i_flags */



	return 0;

out_err:

	spin_unlock(&integrity_iint_lock);

	mutex_unlock(&inode->i_mutex);	/* i_flags */

	iint_free(new_iint);



	return rc;

	return iint;

}



/**

security/integrity/ima/ima_main.c

+4 −9
Original line number Diff line number Diff line
@@ -162,19 +162,14 @@ static int process_measurement(struct file *file, const unsigned char *filename, 
	if (!action)

		return 0;



retry:

	iint = integrity_iint_find(inode);

	if (!iint) {

		rc = integrity_inode_alloc(inode);

		if (!rc || rc == -EEXIST)

			goto retry;

		return rc;

	}



	must_appraise = action & IMA_APPRAISE;



	mutex_lock(&inode->i_mutex);



	iint = integrity_inode_get(inode);

	if (!iint)

		goto out;



	/* Determine if already appraised/measured based on bitmask

	 * (IMA_MEASURE, IMA_MEASURED, IMA_APPRAISE, IMA_APPRAISED) */

	iint->flags |= action;