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ima: remove unnecessary i_mutex locking from ima_rdwr_violation_check() 

Before 2.6.39 inode->i_readcount was maintained by IMA. It was not atomic
and protected using spinlock. For 2.6.39, i_readcount was converted to
atomic and maintaining was moved VFS layer. Spinlock for some unclear
reason was replaced by i_mutex.

After analyzing the code, we came to conclusion that i_mutex locking is
unnecessary, especially when an IMA policy has not been defined.

This patch removes i_mutex locking from ima_rdwr_violation_check().

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
This commit is contained in:
Dmitry Kasatkin 2014-06-13 18:55:47 +03:00 committed by Mimi Zohar
parent b6b8a371f5
commit 2c50b96482
1 changed files with 0 additions and 4 deletions
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4
security/integrity/ima/ima_main.c
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@ -88,8 +88,6 @@ static void ima_rdwr_violation_check(struct file *file)
if (!S_ISREG(inode->i_mode) || !ima_initialized)
return;
mutex_lock(&inode->i_mutex); /* file metadata: permissions, xattr */
if (mode & FMODE_WRITE) {
if (atomic_read(&inode->i_readcount) && IS_IMA(inode)) {
struct integrity_iint_cache *iint;
@ -104,8 +102,6 @@ static void ima_rdwr_violation_check(struct file *file)
send_writers = true;
}
mutex_unlock(&inode->i_mutex);
if (!send_tomtou && !send_writers)
return;