lkml.org 
[lkml]   [2012]   [Mar]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v2 05/11] ima: allocating iint improvements
Date
From: Dmitry Kasatkin <dmitry.kasatkin@intel.com>

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: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
---
include/linux/integrity.h | 7 +++--
security/integrity/iint.c | 45 +++++++++++++++---------------------
security/integrity/ima/ima_main.c | 13 +++-------
3 files changed, 27 insertions(+), 38 deletions(-)
diff --git a/include/linux/integrity.h b/include/linux/integrity.h
index a0c4125..66c5fe9 100644
--- a/include/linux/integrity.h
+++ b/include/linux/integrity.h
@@ -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)
diff --git a/security/integrity/iint.c b/security/integrity/iint.c
index e600986..c91a436 100644
--- a/security/integrity/iint.c
+++ b/security/integrity/iint.c
@@ -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;
}

/**
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index fba2f7b..9fe0597 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -145,19 +145,14 @@ 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;
--
1.7.6.5


\
 
 \ /
  Last update: 2012-03-01 20:19    [from the cache]
©2003-2014 Jasper Spaans. Advertise on this site