commit 497f32337073a2da102c49a53779097b5394711b
author Eric Paris <eparis@redhat.com> Mon Oct 25 14:41:32 2010 -0400
committer Linus Torvalds <torvalds@linux-foundation.org> Tue Oct 26 11:37:18 2010 -0700
tree 203cbcd3f9462737d872e24fb2c847ce9a69de45
parent b575156dafef208415ff0842c392733d16d4ccf1

IMA: use unsigned int instead of long for counters

Currently IMA uses 2 longs in struct inode.  To save space (and as it
seems impossible to overflow 32 bits) we switch these to unsigned int.
The switch to unsigned does require slightly different checks for
underflow, but it isn't complex.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

security/integrity/ima/ima.h

diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index 3d70108..000d13a 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -106,8 +106,8 @@
 	unsigned long flags;
 	u8 digest[IMA_DIGEST_SIZE];
 	struct mutex mutex;	/* protects: version, flags, digest */
-	long readcount;		/* measured files readcount */
-	long writecount;	/* measured files writecount */
+	unsigned int readcount;	/* measured files readcount */
+	unsigned int writecount;/* measured files writecount */
 	struct kref refcount;	/* ima_iint_cache reference count */
 };
 

security/integrity/ima/ima_iint.c

diff --git a/security/integrity/ima/ima_iint.c b/security/integrity/ima/ima_iint.c
index 8e64313..db71a13 100644
--- a/security/integrity/ima/ima_iint.c
+++ b/security/integrity/ima/ima_iint.c
@@ -125,12 +125,12 @@
 	iint->version = 0;
 	iint->flags = 0UL;
 	if (iint->readcount != 0) {
-		printk(KERN_INFO "%s: readcount: %ld\n", __func__,
+		printk(KERN_INFO "%s: readcount: %u\n", __func__,
 		       iint->readcount);
 		iint->readcount = 0;
 	}
 	if (iint->writecount != 0) {
-		printk(KERN_INFO "%s: writecount: %ld\n", __func__,
+		printk(KERN_INFO "%s: writecount: %u\n", __func__,
 		       iint->writecount);
 		iint->writecount = 0;
 	}

security/integrity/ima/ima_main.c

diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 995bd1b..5a1bf3d 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -178,11 +178,18 @@
 			   struct file *file)
 {
 	mode_t mode = file->f_mode;
+	bool dump = false;
+
 	BUG_ON(!mutex_is_locked(&iint->mutex));
 
-	if ((mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ)
+	if ((mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ) {
+		if (unlikely(iint->readcount == 0))
+			dump = true;
 		iint->readcount--;
+	}
 	if (mode & FMODE_WRITE) {
+		if (unlikely(iint->writecount == 0))
+			dump = true;
 		iint->writecount--;
 		if (iint->writecount == 0) {
 			if (iint->version != inode->i_version)
@@ -190,10 +197,8 @@
 		}
 	}
 
-	if (((iint->readcount < 0) ||
-	     (iint->writecount < 0)) &&
-	    !ima_limit_imbalance(file)) {
-		printk(KERN_INFO "%s: open/free imbalance (r:%ld w:%ld)\n",
+	if (dump && !ima_limit_imbalance(file)) {
+		printk(KERN_INFO "%s: open/free imbalance (r:%u w:%u)\n",
 		       __func__, iint->readcount, iint->writecount);
 		dump_stack();
 	}