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From: Eric Dumazet <edumazet@google.com>
To: Jason Xing <kerneljasonxing@gmail.com>
Cc: dsahern@kernel.org, matttbe@kernel.org, martineau@kernel.org,
	 geliang@kernel.org, kuba@kernel.org, pabeni@redhat.com,
	davem@davemloft.net,  mptcp@lists.linux.dev,
	netdev@vger.kernel.org,  Jason Xing <kernelxing@tencent.com>
Subject: Re: [PATCH net-next 2/2] tcp: annotate a data-race around sysctl_tcp_wmem[0]
Date: Fri, 8 Mar 2024 13:51:35 +0100	[thread overview]
Message-ID: <CANn89iLtRYt6U+q_VHb_3Vj2ydmnwsSon4uwPX3+yTJDgoDenQ@mail.gmail.com> (raw)
In-Reply-To: <20240308112504.29099-3-kerneljasonxing@gmail.com>

On Fri, Mar 8, 2024 at 12:25 PM Jason Xing <kerneljasonxing@gmail.com> wrote:
>
> From: Jason Xing <kernelxing@tencent.com>
>
> When reading wmem[0], it could be changed concurrently without
> READ_ONCE() protection. So add one annotation here.
>
> Signed-off-by: Jason Xing <kernelxing@tencent.com>
> ---
>  net/ipv4/tcp.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
> index c5b83875411a..e3904c006e63 100644
> --- a/net/ipv4/tcp.c
> +++ b/net/ipv4/tcp.c
> @@ -975,7 +975,7 @@ int tcp_wmem_schedule(struct sock *sk, int copy)
>          * Use whatever is left in sk->sk_forward_alloc and tcp_wmem[0]
>          * to guarantee some progress.
>          */
> -       left = sock_net(sk)->ipv4.sysctl_tcp_wmem[0] - sk->sk_wmem_queued;
> +       left = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_wmem[0]) - sk->sk_wmem_queued;

SGTM, you could have split the long line...

Reviewed-by: Eric Dumazet <edumazet@google.com>

  reply	other threads:[~2024-03-08 12:51 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-03-08 11:25 [PATCH net-next 0/2] annotate data-races around sysctl_tcp_wmem[0] Jason Xing
2024-03-08 11:25 ` [PATCH net-next 1/2] mptcp: annotate a data-race " Jason Xing
2024-03-08 12:54   ` Eric Dumazet
2024-03-08 20:26   ` Mat Martineau
2024-03-08 11:25 ` [PATCH net-next 2/2] tcp: " Jason Xing
2024-03-08 12:51   ` Eric Dumazet [this message]
2024-03-11 19:39 ` [PATCH net-next 0/2] annotate data-races " patchwork-bot+netdevbpf

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