integrity: add measured_pcrs field to integrity cache

To keep track of which measurements have been extended to which PCRs, this
patch defines a new integrity_iint_cache field named measured_pcrs. This
field is a bitmask of the PCRs measured. Each bit corresponds to a PCR
index. For example, bit 10 corresponds to PCR 10.

Signed-off-by: Eric Richter <erichte@linux.vnet.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

security/integrity/iint.c

@@ -79,6 +79,7 @@ static void iint_free(struct integrity_iint_cache *iint)
 	iint->ima_bprm_status = INTEGRITY_UNKNOWN;
 	iint->ima_read_status = INTEGRITY_UNKNOWN;
 	iint->evm_status = INTEGRITY_UNKNOWN;
+	iint->measured_pcrs = 0;
 	kmem_cache_free(iint_cache, iint);
 }
 
@@ -159,6 +160,7 @@ static void init_once(void *foo)
 	iint->ima_bprm_status = INTEGRITY_UNKNOWN;
 	iint->ima_read_status = INTEGRITY_UNKNOWN;
 	iint->evm_status = INTEGRITY_UNKNOWN;
+	iint->measured_pcrs = 0;
 }
 
 static int __init integrity_iintcache_init(void)

security/integrity/integrity.h

@@ -103,6 +103,7 @@ struct integrity_iint_cache {
 	struct inode *inode;	/* back pointer to inode in question */
 	u64 version;		/* track inode changes */
 	unsigned long flags;
+	unsigned long measured_pcrs;
 	enum integrity_status ima_file_status:4;
 	enum integrity_status ima_mmap_status:4;
 	enum integrity_status ima_bprm_status:4;