From: Jakub Kicinski <kuba@kernel.org>
To: Maxim Mikityanskiy <maximmi@nvidia.com>
Cc: "David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Paolo Abeni <pabeni@redhat.com>,
Boris Pismenny <borisp@nvidia.com>,
Saeed Mahameed <saeedm@nvidia.com>,
Tariq Toukan <tariqt@nvidia.com>,
John Fastabend <john.fastabend@gmail.com>,
Gal Pressman <gal@nvidia.com>, <netdev@vger.kernel.org>
Subject: Re: [PATCH net-next] net/tls: Use RCU API to access tls_ctx->netdev
Date: Mon, 1 Aug 2022 12:44:19 -0700 [thread overview]
Message-ID: <20220801124419.4aaffcac@kernel.org> (raw)
In-Reply-To: <20220801080053.21849-1-maximmi@nvidia.com>
On Mon, 1 Aug 2022 11:00:53 +0300 Maxim Mikityanskiy wrote:
> Currently, tls_device_down synchronizes with tls_device_resync_rx using
> RCU, however, the pointer to netdev is stored using WRITE_ONCE and
> loaded using READ_ONCE.
>
> Although such approach is technically correct (rcu_dereference is
> essentially a READ_ONCE, and rcu_assign_pointer uses WRITE_ONCE to store
> NULL), using special RCU helpers for pointers is more valid, as it
> includes additional checks and might change the implementation
> transparently to the callers.
>
> Mark the netdev pointer as __rcu and use the correct RCU helpers to
> access it. For non-concurrent access pass the right conditions that
> guarantee safe access (locks taken, refcount value). Also use the
> correct helper in mlx5e, where even READ_ONCE was missing.
Oops, looks like we also got some new sparse warnings from this:
2 new warnings in drivers/net/bonding/bond_main.c
1 new warning in drivers/net/ethernet/chelsio/inline_crypto/ch_ktls/chcr_ktls.c
next prev parent reply other threads:[~2022-08-01 19:44 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-01 8:00 [PATCH net-next] net/tls: Use RCU API to access tls_ctx->netdev Maxim Mikityanskiy
2022-08-01 19:42 ` Jakub Kicinski
2022-08-02 12:03 ` Maxim Mikityanskiy
2022-08-02 15:37 ` Jakub Kicinski
2022-08-03 9:33 ` Maxim Mikityanskiy
2022-08-03 14:49 ` Jakub Kicinski
2022-08-03 16:34 ` Paul E. McKenney
2022-08-04 8:08 ` Maxim Mikityanskiy
2022-08-04 16:18 ` Jakub Kicinski
2022-08-05 10:59 ` Maxim Mikityanskiy
2022-08-04 18:40 ` Paul E. McKenney
2022-08-05 10:59 ` Maxim Mikityanskiy
2022-08-01 19:44 ` Jakub Kicinski [this message]
2022-08-02 12:07 ` Maxim Mikityanskiy
2022-08-02 15:38 ` Jakub Kicinski
2022-08-02 16:26 ` kernel test robot
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