[MPTCP] Re: [MPTCP][PATCH v2 mptcp-next 2/5] mptcp: simplify mptcp_pm_nl_add_addr_send_ack debug log

[MPTCP] Re: [MPTCP][PATCH v2 mptcp-next 2/5] mptcp: simplify mptcp_pm_nl_add_addr_send_ack debug log

[Mat Martineau]

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On Thu, 14 Jan 2021, Geliang Tang wrote:

> Print out the debug log of mptcp_pm_nl_add_addr_send_ack in a single line
> when more than one mptcp_addr_signal_status are set.
>
> Signed-off-by: Geliang Tang <geliangtang(a)gmail.com>
> ---
> net/mptcp/pm_netlink.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
> index ed4231efa822..8f4bd2457a97 100644
> --- a/net/mptcp/pm_netlink.c
> +++ b/net/mptcp/pm_netlink.c
> @@ -500,13 +500,15 @@ void mptcp_pm_nl_add_addr_send_ack(struct mptcp_sock *msk)
> 	subflow = list_first_entry_or_null(&msk->conn_list, typeof(*subflow), node);
> 	if (subflow) {
> 		struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
> +		char buf[32] = { 0 };
> 		u8 add_addr;
>
> 		spin_unlock_bh(&msk->pm.lock);
> 		if (mptcp_pm_should_add_signal_ipv6(msk))
> -			pr_debug("send ack for add_addr6");
> +			strcat(buf, "[ipv6]");
> 		if (mptcp_pm_should_add_signal_port(msk))
> -			pr_debug("send ack for add_addr_port");
> +			strcat(buf, "[port]");
> +		pr_debug("send ack for add_addr %s", buf);

pr_debug() calls can be compiled out or involve dynamic debug, so it's 
better to avoid using a buffer on the stack and strcat() like this when 
building the debug output.

>
> 		lock_sock(ssk);
> 		tcp_send_ack(ssk);
> -- 
> 2.29.2

--
Mat Martineau
Intel