Re: [PATCH v4 2/4] RDMA/rxe: Add net namespace support for IPv4/IPv6 sockets

["yanjun.zhu" <yanjun.zhu@linux.dev>]

On 3/9/26 11:54 AM, David Ahern wrote:
> On 3/8/26 5:35 PM, Zhu Yanjun wrote:
>> diff --git a/drivers/infiniband/sw/rxe/rxe_ns.c b/drivers/infiniband/sw/rxe/rxe_ns.c
>> new file mode 100644
>> index 000000000000..6fe056c81ef3
>> --- /dev/null
>> +++ b/drivers/infiniband/sw/rxe/rxe_ns.c
>> @@ -0,0 +1,136 @@
>> +// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
>> +/*
>> + * Copyright (c) 2016 Mellanox Technologies Ltd. All rights reserved.
>> + * Copyright (c) 2015 System Fabric Works, Inc. All rights reserved.
> 
> neither of those copyrights are relevant here.
> 
> 
> 
>> +static void rxe_ns_exit(struct net *net)
>> +{
>> +	/* called when the network namespace is removed
>> +	 */
>> +	struct rxe_ns_sock *ns_sk = net_generic(net, rxe_pernet_id);
>> +	struct sock *sk;
>> +
>> +	sk = rcu_dereference(ns_sk->rxe_sk4);
> 
> [  323.527911] =============================
> [  323.527915] WARNING: suspicious RCU usage
> [  323.527918] 7.0.0-rc1-debug+ #3 Tainted: G        W
> [  323.527922] -----------------------------
> [  323.527925] drivers/infiniband/sw/rxe/rxe_ns.c:49 suspicious
> rcu_dereference_check() usage!
> [  323.527929]
> 
>> +	if (sk) {
>> +		rcu_assign_pointer(ns_sk->rxe_sk4, NULL);
>> +		udp_tunnel_sock_release(sk->sk_socket);
>> +	}
>> +
>> +#if IS_ENABLED(CONFIG_IPV6)
>> +	sk = rcu_dereference(ns_sk->rxe_sk6);
> 
> [  323.528243] =============================
> [  323.528245] WARNING: suspicious RCU usage
> [  323.528248] 7.0.0-rc1-debug+ #3 Tainted: G        W
> [  323.528251] -----------------------------
> [  323.528253] drivers/infiniband/sw/rxe/rxe_ns.c:56 suspicious
> rcu_dereference_check() usage!
> 
> 
> you should always run tests with a debug kernel that has kmemleak and
> lock debugging enabled.
> 
> 
>> +#else /* IPV6 */
>> +
>> +struct sock *rxe_ns_pernet_sk6(struct net *net)
>> +{
>> +	return NULL;
>> +}
>> +
>> +void rxe_ns_pernet_set_sk6(struct net *net, struct sock *sk)
>> +{
>> +}
> 
> This branch is typically done as an inline in the header file.
> 
> 

Got it. All the above problems are fixed in the latest commit.

Zhu Yanjun