NetLabel: convert the unlabeled accept flag to use RCU
Currently the NetLabel unlabeled packet accept flag is an atomic type and it
is checked for every non-NetLabel packet which comes into the system but rarely
ever changed. This patch changes this flag to a normal integer and protects it
with RCU locking.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
index a1d4ae5..07283e1 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -47,7 +47,8 @@
#include "netlabel_unlabeled.h"
/* Accept unlabeled packets flag */
-static atomic_t netlabel_unlabel_accept_flg = ATOMIC_INIT(0);
+static DEFINE_SPINLOCK(netlabel_unlabel_acceptflg_lock);
+static u8 netlabel_unlabel_acceptflg = 0;
/* NetLabel Generic NETLINK CIPSOv4 family */
static struct genl_family netlbl_unlabel_gnl_family = {
@@ -82,8 +83,12 @@
struct audit_buffer *audit_buf;
u8 old_val;
- old_val = atomic_read(&netlabel_unlabel_accept_flg);
- atomic_set(&netlabel_unlabel_accept_flg, value);
+ rcu_read_lock();
+ old_val = netlabel_unlabel_acceptflg;
+ spin_lock(&netlabel_unlabel_acceptflg_lock);
+ netlabel_unlabel_acceptflg = value;
+ spin_unlock(&netlabel_unlabel_acceptflg_lock);
+ rcu_read_unlock();
audit_buf = netlbl_audit_start_common(AUDIT_MAC_UNLBL_ALLOW,
audit_info);
@@ -148,9 +153,11 @@
goto list_failure;
}
+ rcu_read_lock();
ret_val = nla_put_u8(ans_skb,
NLBL_UNLABEL_A_ACPTFLG,
- atomic_read(&netlabel_unlabel_accept_flg));
+ netlabel_unlabel_acceptflg);
+ rcu_read_unlock();
if (ret_val != 0)
goto list_failure;
@@ -236,10 +243,17 @@
*/
int netlbl_unlabel_getattr(struct netlbl_lsm_secattr *secattr)
{
- if (atomic_read(&netlabel_unlabel_accept_flg) == 1)
- return netlbl_secattr_init(secattr);
+ int ret_val;
- return -ENOMSG;
+ rcu_read_lock();
+ if (netlabel_unlabel_acceptflg == 1) {
+ netlbl_secattr_init(secattr);
+ ret_val = 0;
+ } else
+ ret_val = -ENOMSG;
+ rcu_read_unlock();
+
+ return ret_val;
}
/**
