[PATCH] xfrm: kill xfrm_dev_{state,policy}_flush_secctx_check()

[Tetsuo Handa]

Since xfrm_dev_{state,policy}_flush() are called from only NETDEV_DOWN and
NETDEV_UNREGISTER events, making xfrm_dev_{state,policy}_flush() no-op by
returning an error value from xfrm_dev_{state,policy}_flush_secctx_check()
is pointless. Especially, if xfrm_dev_{state,policy}_flush_secctx_check()
returned an error value upon NETDEV_UNREGISTER event, the system will hung
up with

  unregister_netdevice: waiting for $dev to become free. Usage count = $count

message because the reference to $dev acquired by
xfrm_dev_{state,policy}_add() cannot be released.

Signed-off-by: Tetsuo Handa <penguin-kernel at I-love.SAKURA.ne.jp>
---
 net/xfrm/xfrm_policy.c | 35 -----------------------------------
 net/xfrm/xfrm_state.c  | 33 ---------------------------------
 2 files changed, 68 deletions(-)

diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 62486f866975..f4df6491095f 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -1778,41 +1778,12 @@ xfrm_policy_flush_secctx_check(struct net *net, u8 type, bool task_valid)
 	}
 	return err;
 }
-
-static inline int xfrm_dev_policy_flush_secctx_check(struct net *net,
-						     struct net_device *dev,
-						     bool task_valid)
-{
-	struct xfrm_policy *pol;
-	int err = 0;
-
-	list_for_each_entry(pol, &net->xfrm.policy_all, walk.all) {
-		if (pol->walk.dead ||
-		    xfrm_policy_id2dir(pol->index) >= XFRM_POLICY_MAX ||
-		    pol->xdo.dev != dev)
-			continue;
-
-		err = security_xfrm_policy_delete(pol->security);
-		if (err) {
-			xfrm_audit_policy_delete(pol, 0, task_valid);
-			return err;
-		}
-	}
-	return err;
-}
 #else
 static inline int
 xfrm_policy_flush_secctx_check(struct net *net, u8 type, bool task_valid)
 {
 	return 0;
 }
-
-static inline int xfrm_dev_policy_flush_secctx_check(struct net *net,
-						     struct net_device *dev,
-						     bool task_valid)
-{
-	return 0;
-}
 #endif
 
 int xfrm_policy_flush(struct net *net, u8 type, bool task_valid)
@@ -1861,11 +1832,6 @@ int xfrm_dev_policy_flush(struct net *net, struct net_device *dev,
 	struct xfrm_policy *pol;
 
 	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
-
-	err = xfrm_dev_policy_flush_secctx_check(net, dev, task_valid);
-	if (err)
-		goto out;
-
 again:
 	list_for_each_entry(pol, &net->xfrm.policy_all, walk.all) {
 		if (pol->walk.dead)
@@ -1888,7 +1854,6 @@ int xfrm_dev_policy_flush(struct net *net, struct net_device *dev,
 		__xfrm_policy_inexact_flush(net);
 	else
 		err = -ESRCH;
-out:
 	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
 	return err;
 }
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index 98b362d51836..855778177558 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -881,41 +881,12 @@ xfrm_state_flush_secctx_check(struct net *net, u8 proto, bool task_valid)
 
 	return err;
 }
-
-static inline int
-xfrm_dev_state_flush_secctx_check(struct net *net, struct net_device *dev, bool task_valid)
-{
-	int i, err = 0;
-
-	for (i = 0; i <= net->xfrm.state_hmask; i++) {
-		struct xfrm_state *x;
-		struct xfrm_dev_offload *xso;
-
-		hlist_for_each_entry(x, net->xfrm.state_bydst+i, bydst) {
-			xso = &x->xso;
-
-			if (xso->dev == dev &&
-			   (err = security_xfrm_state_delete(x)) != 0) {
-				xfrm_audit_state_delete(x, 0, task_valid);
-				return err;
-			}
-		}
-	}
-
-	return err;
-}
 #else
 static inline int
 xfrm_state_flush_secctx_check(struct net *net, u8 proto, bool task_valid)
 {
 	return 0;
 }
-
-static inline int
-xfrm_dev_state_flush_secctx_check(struct net *net, struct net_device *dev, bool task_valid)
-{
-	return 0;
-}
 #endif
 
 int xfrm_state_flush(struct net *net, u8 proto, bool task_valid)
@@ -966,9 +937,6 @@ int xfrm_dev_state_flush(struct net *net, struct net_device *dev, bool task_vali
 	int i, err = 0, cnt = 0;
 
 	spin_lock_bh(&net->xfrm.xfrm_state_lock);
-	err = xfrm_dev_state_flush_secctx_check(net, dev, task_valid);
-	if (err)
-		goto out;
 
 	err = -ESRCH;
 	for (i = 0; i <= net->xfrm.state_hmask; i++) {
@@ -997,7 +965,6 @@ int xfrm_dev_state_flush(struct net *net, struct net_device *dev, bool task_vali
 	if (cnt)
 		err = 0;
 
-out:
 	spin_unlock_bh(&net->xfrm.xfrm_state_lock);
 
 	spin_lock_bh(&xfrm_state_dev_gc_lock);
-- 
2.47.3