From: Eric Paris <eparis@redhat.com>
To: linux-kernel@vger.kernel.org,
linux-security-module@vger.kernel.org,
linux-fsdevel@vger.kernel.org
Cc: hch@infradead.org, zohar@us.ibm.com, warthog9@kernel.org,
david@fromorbit.com, jmorris@namei.org, kyle@mcmartin.ca,
hpa@zytor.com, akpm@linux-foundation.org,
torvalds@linux-foundation.org, mingo@elte.hu, eparis@redhat.com,
viro@zeniv.linux.org.uk
Subject: [PATCH 3/6] IMA: use unsigned int instead of long for counters
Date: Tue, 19 Oct 2010 18:58:26 -0400 [thread overview]
Message-ID: <20101019225826.12396.52631.stgit@paris.rdu.redhat.com> (raw)
In-Reply-To: <20101019225813.12396.2564.stgit@paris.rdu.redhat.com>
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>
---
include/linux/fs.h | 4 ++--
security/integrity/ima/ima_iint.c | 4 ++--
security/integrity/ima/ima_main.c | 15 ++++++++++-----
3 files changed, 14 insertions(+), 9 deletions(-)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 593bb4d..8f46e5b 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -778,8 +778,8 @@ struct inode {
#endif
#ifdef CONFIG_IMA
/* all protected by i_mutex */
- long i_readers; /* struct files open RO */
- long i_writers; /* struct files open WR */
+ unsigned int i_readers; /* struct files open RO */
+ unsigned int i_writers; /* struct files open WR */
#endif
#ifdef CONFIG_FS_POSIX_ACL
struct posix_acl *i_acl;
diff --git a/security/integrity/ima/ima_iint.c b/security/integrity/ima/ima_iint.c
index 2dc32d6..d327840 100644
--- a/security/integrity/ima/ima_iint.c
+++ b/security/integrity/ima/ima_iint.c
@@ -76,9 +76,9 @@ out:
void ima_check_counters(struct inode *inode)
{
if (inode->i_readers)
- printk(KERN_INFO "%s: readcount: %ld\n", __func__, inode->i_readers);
+ printk(KERN_INFO "%s: readcount: %u\n", __func__, inode->i_readers);
if (inode->i_writers)
- printk(KERN_INFO "%s: writers: %ld\n", __func__, inode->i_writers);
+ printk(KERN_INFO "%s: writers: %u\n", __func__, inode->i_writers);
inode->i_readers = 0;
inode->i_writers = 0;
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 92235a0..68ecb43 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -181,12 +181,19 @@ static void ima_dec_counts(struct ima_iint_cache *iint, struct inode *inode,
struct file *file)
{
mode_t mode = file->f_mode;
+ bool dump = false;
+
BUG_ON(!mutex_is_locked(&iint->mutex));
BUG_ON(!mutex_is_locked(&inode->i_mutex));
- if ((mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ)
+ if ((mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ) {
+ if (unlikely(inode->i_readers == 0))
+ dump = true;
inode->i_readers--;
+ }
if (mode & FMODE_WRITE) {
+ if (unlikely(inode->i_writers == 0))
+ dump = true;
inode->i_writers--;
if (inode->i_writers == 0) {
if (iint->version != inode->i_version)
@@ -194,10 +201,8 @@ static void ima_dec_counts(struct ima_iint_cache *iint, struct inode *inode,
}
}
- if (((inode->i_readers < 0) ||
- (inode->i_writers < 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__, inode->i_readers, inode->i_writers);
dump_stack();
}
next prev parent reply other threads:[~2010-10-19 22:59 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-10-19 22:58 [PATCH 1/6] IMA: move read/write counters into struct inode Eric Paris
2010-10-19 22:58 ` [PATCH 2/6] IMA: drop the inode opencount since it isn't needed for operation Eric Paris
2010-10-19 22:58 ` Eric Paris [this message]
2010-10-19 22:58 ` [PATCH 4/6] IMA: only allocate iint when needed Eric Paris
2010-10-20 3:53 ` Al Viro
2010-10-19 22:58 ` [PATCH 5/6] IMA: use rbtree instead of radix tree for inode information cache Eric Paris
2010-10-19 23:17 ` Dave Chinner
2010-10-20 11:31 ` Peter Zijlstra
2010-10-20 22:05 ` Dave Chinner
2010-10-20 22:22 ` Linus Torvalds
2010-10-20 22:47 ` Trond Myklebust
2010-10-21 0:58 ` Linus Torvalds
2010-10-21 2:17 ` Dave Chinner
2010-10-19 22:58 ` [PATCH 6/6] IMA: use i_writecount rather than a private counter Eric Paris
2010-10-20 0:25 ` [PATCH 1/6] IMA: move read/write counters into struct inode Linus Torvalds
2010-10-23 3:01 ` Eric Paris
2010-10-24 6:52 ` Mimi Zohar
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