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>

1 files changed, 3 insertions, 10 deletions

diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index d3963de6003..da36d2c085a 100644
--- a/security/integrity/ima/ima_api.c
+++ b/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;
 }