From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-186.mta1.migadu.com (out-186.mta1.migadu.com [95.215.58.186]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B48E33D6CD0 for ; Tue, 14 Apr 2026 11:24:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.186 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776165863; cv=none; b=LEFDMSV3GJM+o4QKO3e7KQSZwh5A9xBDq+dW3RySOcwI4AtK4fntYgAXJyXC9aCygc8ENW2q5Sd90azLj3sTZRXMgtIiEZi5bX197CYiBoPbFOfWrmMkkBiZp5sCUHC0H31GD+jQQ1+vFuRf5sNHpHNML8zZVy5JxzRu5vF5/MQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776165863; c=relaxed/simple; bh=0XKwPrVsLYqMkdidCVFKYLqUJ4c4EfyJ1ob1+L0+szc=; h=From:To:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=g3bK0jHTI7X790rwfrKwF95Od9vPMhSA7S4y8b3htX5Z/Sxvu7V1hAWG3hJIFrGK2QndEL1sZZxRpqui6qzIxkQMNlIWzHJR7cKIuh9qaELGg7aU7+jCiZeX3tf62zET3jbate2mzo3G0xDqmKmL4zXfduUxPE0gl+wN4q7QNW0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=xI+6m4mw; arc=none smtp.client-ip=95.215.58.186 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="xI+6m4mw" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1776165859; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=9yPm78UqHyZkm1QqrS3WLRW2slYckpyvj6iqSa7dJaU=; b=xI+6m4mw4iR24mWikEbqUbtnMYM5+ZpcfMM5M6FbhOQ4Uufl8H2/De2LPdo8YObnMU+8Ud 8Z2Ami6lZae5H3ObtR+5Ex8+w/cyMVqW7NSK4cZ7tjfp+iKINoDXYnJqAchxvk38DA+ZxR 9EAsw2MiFlpnwzkFoGHnYiv6jAeT5rI= From: KaFai Wan To: edumazet@google.com, ncardwell@google.com, kuniyu@google.com, davem@davemloft.net, dsahern@kernel.org, kuba@kernel.org, pabeni@redhat.com, horms@kernel.org, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev, eddyz87@gmail.com, memxor@gmail.com, song@kernel.org, yonghong.song@linux.dev, jolsa@kernel.org, shuah@kernel.org, kafai.wan@linux.dev, sdf@fomichev.me, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: [PATCH bpf-next 2/2] selftests/bpf: Cover TCP_NODELAY in hdr opt callback Date: Tue, 14 Apr 2026 19:23:10 +0800 Message-ID: <20260414112310.1285783-3-kafai.wan@linux.dev> In-Reply-To: <20260414112310.1285783-1-kafai.wan@linux.dev> References: <20260414112310.1285783-1-kafai.wan@linux.dev> Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT Add a sockops test program that enables BPF_SOCK_OPS_WRITE_HDR_OPT_CB_FLAG on connection setup and calls bpf_setsockopt(TCP_NODELAY) from BPF_SOCK_OPS_HDR_OPT_LEN_CB. Exercise the connection by sending data after the socket is established. Before the fix, this setup can recurse through tcp_push_pending_frames() and bpf_skops_hdr_opt_len() until the kernel hits a stack guard page. After the fix, the connection continues to make forward progress and the data exchange completes. Signed-off-by: KaFai Wan --- .../bpf/prog_tests/tcp_hdr_options.c | 34 +++++++++++++++++++ .../bpf/progs/test_misc_tcp_hdr_options.c | 18 ++++++++++ 2 files changed, 52 insertions(+) diff --git a/tools/testing/selftests/bpf/prog_tests/tcp_hdr_options.c b/tools/testing/selftests/bpf/prog_tests/tcp_hdr_options.c index 56685fc03c7e..f361f9c7bf59 100644 --- a/tools/testing/selftests/bpf/prog_tests/tcp_hdr_options.c +++ b/tools/testing/selftests/bpf/prog_tests/tcp_hdr_options.c @@ -513,6 +513,39 @@ static void misc(void) bpf_link__destroy(link); } +static void hdr_sockopt(void) +{ + const char send_msg[] = "MISC!!!"; + char recv_msg[sizeof(send_msg)]; + const unsigned int nr_data = 2; + struct bpf_link *link; + struct sk_fds sk_fds; + int i, ret; + + link = bpf_program__attach_cgroup(misc_skel->progs.misc_hdr_sockopt, cg_fd); + if (!ASSERT_OK_PTR(link, "attach_cgroup(misc_hdr_sockopt)")) + return; + + if (sk_fds_connect(&sk_fds, false)) { + bpf_link__destroy(link); + return; + } + + for (i = 0; i < nr_data; i++) { + ret = send(sk_fds.active_fd, send_msg, sizeof(send_msg), 0); + if (!ASSERT_EQ(ret, sizeof(send_msg), "send(msg)")) + goto check_linum; + + ret = read(sk_fds.passive_fd, recv_msg, sizeof(recv_msg)); + if (!ASSERT_EQ(ret, sizeof(send_msg), "read(msg)")) + goto check_linum; + } + +check_linum: + sk_fds_close(&sk_fds); + bpf_link__destroy(link); +} + struct test { const char *desc; void (*run)(void); @@ -526,6 +559,7 @@ static struct test tests[] = { DEF_TEST(fastopen_estab), DEF_TEST(fin), DEF_TEST(misc), + DEF_TEST(hdr_sockopt), }; void test_tcp_hdr_options(void) diff --git a/tools/testing/selftests/bpf/progs/test_misc_tcp_hdr_options.c b/tools/testing/selftests/bpf/progs/test_misc_tcp_hdr_options.c index d487153a839d..e1dc7246193e 100644 --- a/tools/testing/selftests/bpf/progs/test_misc_tcp_hdr_options.c +++ b/tools/testing/selftests/bpf/progs/test_misc_tcp_hdr_options.c @@ -326,4 +326,22 @@ int misc_estab(struct bpf_sock_ops *skops) return CG_OK; } +SEC("sockops") +int misc_hdr_sockopt(struct bpf_sock_ops *skops) +{ + int true_val = 1; + + switch (skops->op) { + case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB: + case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB: + set_hdr_cb_flags(skops, 0); + break; + case BPF_SOCK_OPS_HDR_OPT_LEN_CB: + bpf_setsockopt(skops, SOL_TCP, TCP_NODELAY, &true_val, sizeof(true_val)); + break; + } + + return 0; +} + char _license[] SEC("license") = "GPL"; -- 2.43.0