On 10/10/17 10:41 AM, David Ahern wrote:
> @@ -988,16 +987,23 @@ ipv6_add_addr(struct inet6_dev *idev, const struct
> in6_addr *addr,
> goto out2;
> }
>
> - i6vi.i6vi_addr = *addr;
> - i6vi.i6vi_dev = idev;
> - rcu_read_unlock_bh();
> + /* validator notifier needs to be blocking;
> + * do not call in softirq context
> + */
> + if (!in_softirq()) {
> + struct in6_validator_info i6vi = {
> + .i6vi_addr = *addr,
> + .i6vi_dev = idev,
> + };
>
> - err = inet6addr_validator_notifier_call_chain(NETDEV_UP, &i6vi);
> + rcu_read_unlock_bh();
> + err = inet6addr_validator_notifier_call_chain(NETDEV_UP, &i6vi);
> + rcu_read_lock_bh();
>
> - rcu_read_lock_bh();
> - err = notifier_to_errno(err);
> - if (err)
> - goto out2;
> + err = notifier_to_errno(err);
> + if (err)
> + goto out2;
> + }
>
> spin_lock(&addrconf_hash_lock);
>
The rcu_read_unlock_bh needs to be done before the in_softirq check.
With the change below I get the RIF overload with IPv6 addresses and I
verified the validator is skipped for RAs.
$ ip -batch vlan-ipv6-addr-batch
Error: spectrum: Exceeded number of supported router interfaces.
Command failed vlan-ipv6-addr-batch:683
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 0bad4a800f73..d9c5b29a3b8b 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -988,6 +988,8 @@ ipv6_add_addr(struct inet6_dev *idev, const struct
in6_addr *addr,
goto out2;
}
+ rcu_read_unlock_bh();
+
/* validator notifier needs to be blocking;
* do not call in softirq context
*/
@@ -998,15 +1000,14 @@ ipv6_add_addr(struct inet6_dev *idev, const
struct in6_addr *addr,
.extack = extack,
};
- rcu_read_unlock_bh();
err = inet6addr_validator_notifier_call_chain(NETDEV_UP,
&i6vi);
- rcu_read_lock_bh();
-
err = notifier_to_errno(err);
if (err)
- goto out2;
+ goto out1;
}
+ rcu_read_lock_bh();
+
spin_lock(&addrconf_hash_lock);
/* Ignore adding duplicate addresses on an interface */
@@ -1079,7 +1080,7 @@ ipv6_add_addr(struct inet6_dev *idev, const struct
in6_addr *addr,
write_unlock(&idev->lock);
out2:
rcu_read_unlock_bh();
-
+out1:
if (likely(err == 0))
inet6addr_notifier_call_chain(NETDEV_UP, ifa);
else {
