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authorDmitry Kasatkin <dmitry.kasatkin@intel.com>2011-10-19 13:04:40 +0400
committerMimi Zohar <zohar@linux.vnet.ibm.com>2012-09-07 22:57:45 +0400
commitbf2276d10ce58ff44ab8857266a6718024496af6 (patch)
tree7be39c026fd30856248f68c964d0f1e2ae703c25
parent07f6a79415d7d502ee0c7d02ace6594a7be7429a (diff)
downloadlinux-bf2276d10ce58ff44ab8857266a6718024496af6.tar.xz
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: Dmitry Kasatkin <dmitry.kasatkin@intel.com> Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
-rw-r--r--include/linux/integrity.h7
-rw-r--r--security/integrity/iint.c45
-rw-r--r--security/integrity/ima/ima_main.c13
3 files changed, 27 insertions, 38 deletions
diff --git a/include/linux/integrity.h b/include/linux/integrity.h
index a0c41256cb92..66c5fe9550a5 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 e600986aa49f..c91a436e13ac 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 6eb28d47e74b..df6521296051 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -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;