tcp: tcp_get_info() should fetch socket fields once (fad9dfef) · Commits · 戴 / test

tcp_get_info() can be called without holding socket lock, so any socket fields can change under us. Use READ_ONCE() to fetch sk_pacing_rate and sk_max_pacing_rate Fixes: ("tcp: add pacing_rate information into tcp_info") Signed-off-by:

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

David S. Miller <davem@davemloft.net>

net/ipv4/tcp.c

+6 −4

Original line number	Diff line number	Diff line
		@@ -2595,6 +2595,7 @@ void tcp_get_info(const struct sock sk, struct tcp_info info)
		const struct tcp_sock *tp = tcp_sk(sk);
		const struct inet_connection_sock *icsk = inet_csk(sk);
		u32 now = tcp_time_stamp;
		u32 rate;

		memset(info, 0, sizeof(*info));

		@@ -2655,10 +2656,11 @@ void tcp_get_info(const struct sock sk, struct tcp_info info)

		info->tcpi_total_retrans = tp->total_retrans;

		info->tcpi_pacing_rate = sk->sk_pacing_rate != ~0U ?
		sk->sk_pacing_rate : ~0ULL;
		info->tcpi_max_pacing_rate = sk->sk_max_pacing_rate != ~0U ?
		sk->sk_max_pacing_rate : ~0ULL;
		rate = READ_ONCE(sk->sk_pacing_rate);
		info->tcpi_pacing_rate = rate != ~0U ? rate : ~0ULL;

		rate = READ_ONCE(sk->sk_max_pacing_rate);
		info->tcpi_max_pacing_rate = rate != ~0U ? rate : ~0ULL;
		}
		EXPORT_SYMBOL_GPL(tcp_get_info);

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