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ima: remove unnecessary call to ima_must_measure

The original ima_must_measure() function based its results on cached
iint information, which required an iint be allocated for all files.
Currently, an iint is allocated only for files in policy.  As a result,
for those files in policy, ima_must_measure() is now called twice: once
to determine if the inode is in the measurement policy and, the second
time, to determine if it needs to be measured/re-measured.

The second call to ima_must_measure() unnecessarily checks to see if
the file is in policy. As we already know the file is in policy, this
patch removes the second unnecessary call to ima_must_measure(), removes
the vestige iint parameter, and just checks the iint directly to determine
if the inode has been measured or needs to be measured/re-measured.

Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: Eric Paris <eparis@redhat.com>
master
Mimi Zohar 11 years ago
parent
commit
1adace9bb0
  1. 3
      security/integrity/ima/ima.h
  2. 13
      security/integrity/ima/ima_api.c
  3. 6
      security/integrity/ima/ima_main.c

3
security/integrity/ima/ima.h

@ -110,8 +110,7 @@ struct ima_iint_cache {
};
/* LIM API function definitions */
int ima_must_measure(struct ima_iint_cache *iint, struct inode *inode,
int mask, int function);
int ima_must_measure(struct inode *inode, int mask, int function);
int ima_collect_measurement(struct ima_iint_cache *iint, struct file *file);
void ima_store_measurement(struct ima_iint_cache *iint, struct file *file,
const unsigned char *filename);

13
security/integrity/ima/ima_api.c

@ -105,20 +105,13 @@ err_out:
* mask: contains the permission mask
* fsmagic: hex value
*
* Must be called with iint->mutex held.
*
* Return 0 to measure. Return 1 if already measured.
* For matching a DONT_MEASURE policy, no policy, or other
* error, return an error code.
* Return 0 to measure. For matching a DONT_MEASURE policy, no policy,
* or other error, return an error code.
*/
int ima_must_measure(struct ima_iint_cache *iint, struct inode *inode,
int mask, int function)
int ima_must_measure(struct inode *inode, int mask, int function)
{
int must_measure;
if (iint && iint->flags & IMA_MEASURED)
return 1;
must_measure = ima_match_policy(inode, function, mask);
return must_measure ? 0 : -EACCES;
}

6
security/integrity/ima/ima_main.c

@ -65,7 +65,7 @@ static void ima_rdwr_violation_check(struct file *file)
goto out;
}
rc = ima_must_measure(NULL, inode, MAY_READ, FILE_CHECK);
rc = ima_must_measure(inode, MAY_READ, FILE_CHECK);
if (rc < 0)
goto out;
@ -127,7 +127,7 @@ static int process_measurement(struct file *file, const unsigned char *filename,
if (!ima_initialized || !S_ISREG(inode->i_mode))
return 0;
rc = ima_must_measure(NULL, inode, mask, function);
rc = ima_must_measure(inode, mask, function);
if (rc != 0)
return rc;
retry:
@ -141,7 +141,7 @@ retry:
mutex_lock(&iint->mutex);
rc = ima_must_measure(iint, inode, mask, function);
rc = iint->flags & IMA_MEASURED ? 1 : 0;
if (rc != 0)
goto out;

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