IMA: clean up the IMA counts updating code

We currently have a lot of duplicated code around ima file counts.  Clean
that all up.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Eric Paris 2009-12-04 15:48:00 -05:00 committed by Al Viro
parent 9353384ec8
commit e0d5bd2aec
2 changed files with 70 additions and 49 deletions

View File

@ -97,7 +97,6 @@ static inline unsigned long ima_hash_key(u8 *digest)
/* iint cache flags */
#define IMA_MEASURED 1
#define IMA_IINT_DUMP_STACK 512
/* integrity data associated with an inode */
struct ima_iint_cache {

View File

@ -13,8 +13,8 @@
* License.
*
* File: ima_main.c
* implements the IMA hooks: ima_bprm_check, ima_file_mmap,
* and ima_path_check.
* implements the IMA hooks: ima_bprm_check, ima_file_mmap,
* and ima_path_check.
*/
#include <linux/module.h>
#include <linux/file.h>
@ -35,6 +35,69 @@ static int __init hash_setup(char *str)
}
__setup("ima_hash=", hash_setup);
/*
* Update the counts given an fmode_t
*/
static void ima_inc_counts(struct ima_iint_cache *iint, fmode_t mode)
{
BUG_ON(!mutex_is_locked(&iint->mutex));
iint->opencount++;
if ((mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ)
iint->readcount++;
if (mode & FMODE_WRITE)
iint->writecount++;
}
/*
* Update the counts given open flags instead of fmode
*/
static void ima_inc_counts_flags(struct ima_iint_cache *iint, int flags)
{
ima_inc_counts(iint, (__force fmode_t)((flags+1) & O_ACCMODE));
}
/*
* Decrement ima counts
*/
static void ima_dec_counts(struct ima_iint_cache *iint, struct inode *inode,
fmode_t mode)
{
BUG_ON(!mutex_is_locked(&iint->mutex));
iint->opencount--;
if ((mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ)
iint->readcount--;
if (mode & FMODE_WRITE) {
iint->writecount--;
if (iint->writecount == 0) {
if (iint->version != inode->i_version)
iint->flags &= ~IMA_MEASURED;
}
}
if ((iint->opencount < 0) ||
(iint->readcount < 0) ||
(iint->writecount < 0)) {
static int dumped;
if (dumped)
return;
dumped = 1;
printk(KERN_INFO "%s: open/free imbalance (r:%ld w:%ld o:%ld)\n",
__FUNCTION__, iint->readcount, iint->writecount,
iint->opencount);
dump_stack();
}
}
static void ima_dec_counts_flags(struct ima_iint_cache *iint,
struct inode *inode, int flags)
{
ima_dec_counts(iint, inode, (__force fmode_t)((flags+1) & O_ACCMODE));
}
/**
* ima_file_free - called on __fput()
* @file: pointer to file structure being freed
@ -54,29 +117,7 @@ void ima_file_free(struct file *file)
return;
mutex_lock(&iint->mutex);
if (iint->opencount <= 0) {
printk(KERN_INFO
"%s: %s open/free imbalance (r:%ld w:%ld o:%ld f:%ld)\n",
__FUNCTION__, file->f_dentry->d_name.name,
iint->readcount, iint->writecount,
iint->opencount, atomic_long_read(&file->f_count));
if (!(iint->flags & IMA_IINT_DUMP_STACK)) {
dump_stack();
iint->flags |= IMA_IINT_DUMP_STACK;
}
}
iint->opencount--;
if ((file->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ)
iint->readcount--;
if (file->f_mode & FMODE_WRITE) {
iint->writecount--;
if (iint->writecount == 0) {
if (iint->version != inode->i_version)
iint->flags &= ~IMA_MEASURED;
}
}
ima_dec_counts(iint, inode, file->f_mode);
mutex_unlock(&iint->mutex);
kref_put(&iint->refcount, iint_free);
}
@ -116,8 +157,7 @@ static int get_path_measurement(struct ima_iint_cache *iint, struct file *file,
{
int rc = 0;
iint->opencount++;
iint->readcount++;
ima_inc_counts(iint, file->f_mode);
rc = ima_collect_measurement(iint, file);
if (!rc)
@ -125,15 +165,6 @@ static int get_path_measurement(struct ima_iint_cache *iint, struct file *file,
return rc;
}
static void ima_update_counts(struct ima_iint_cache *iint, int mask)
{
iint->opencount++;
if ((mask & MAY_WRITE) || (mask == 0))
iint->writecount++;
else if (mask & (MAY_READ | MAY_EXEC))
iint->readcount++;
}
/**
* ima_path_check - based on policy, collect/store measurement.
* @path: contains a pointer to the path to be measured
@ -167,7 +198,7 @@ int ima_path_check(struct path *path, int mask, int update_counts)
mutex_lock(&iint->mutex);
if (update_counts)
ima_update_counts(iint, mask);
ima_inc_counts_flags(iint, mask);
rc = ima_must_measure(iint, inode, MAY_READ, PATH_CHECK);
if (rc < 0)
@ -260,11 +291,7 @@ void ima_counts_put(struct path *path, int mask)
return;
mutex_lock(&iint->mutex);
iint->opencount--;
if ((mask & MAY_WRITE) || (mask == 0))
iint->writecount--;
else if (mask & (MAY_READ | MAY_EXEC))
iint->readcount--;
ima_dec_counts_flags(iint, inode, mask);
mutex_unlock(&iint->mutex);
kref_put(&iint->refcount, iint_free);
@ -290,12 +317,7 @@ void ima_counts_get(struct file *file)
if (!iint)
return;
mutex_lock(&iint->mutex);
iint->opencount++;
if ((file->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ)
iint->readcount++;
if (file->f_mode & FMODE_WRITE)
iint->writecount++;
ima_inc_counts(iint, file->f_mode);
mutex_unlock(&iint->mutex);
kref_put(&iint->refcount, iint_free);