From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-182.mta0.migadu.com (out-182.mta0.migadu.com [91.218.175.182]) (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 F37712BD5A8 for ; Thu, 12 Mar 2026 07:26:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773300367; cv=none; b=dx9aYEEq8w6WMFaas5G2silVUNFTmBgYyMtFz0a1EAEDvXv+pdPu3IARwAbmPGen+oDsGmVN4a5OmTCtSt/KhERJ45uJb0uyeV9bwlsWpBpGNesve/lyWRyS4505x2JBhih0YvadbhJmly8gAXrJww4yfCJ17IOKN0CJ59cs1Ug= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773300367; c=relaxed/simple; bh=OyUkZW+xDkqR8cfyu8NdoZsHWfNlfPEk6iBKWvt28fY=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=kOzEyM9ix8TlyHittvpLoz41GZz/k9p4rMyG/cubZa4Q2nXlxdt/SJDGgydat2ER7hFFfIQ1zw8WZm4UzW8TuRcIpqXlj+hi3AmsGnE/w0bcQzeyj5DJOPXeiww8ldcJPRF6+kW5HLnctSaxAyRFbaYwIVLwc81iTJsrYv6Y6Fk= 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=jS9R1ZdV; arc=none smtp.client-ip=91.218.175.182 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="jS9R1ZdV" 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=1773300362; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=5UFGjeC6UydJCvXkg1Dj1jw+Nq0p5HrafCwwFZ8Izu4=; b=jS9R1ZdVYPrCF4BXDMXSRthDYskWq3XZl29XC732R7pNsMdj082hcfuXYSGCYndMcpPPnL 5IgBZxHfHDzD6Y04nh0J9eQBaWDxG+vmwPuU4L2kiYde5U52IYWGhN11eQLk+Uk363QEUf ICOKcWlUXWD9lL5OxVV3E15RpjA3gic= From: Jiayuan Chen To: bpf@vger.kernel.org Cc: Jiayuan Chen , Jiayuan Chen , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Eduard Zingerman , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Shuah Khan , Ihor Solodrai , Jakub Sitnicki , linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH bpf v1] selftests/bpf: Fix sockmap_multi_channels reliability Date: Thu, 12 Mar 2026 15:25:44 +0800 Message-ID: <20260312072549.6766-1-jiayuan.chen@linux.dev> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT From: Jiayuan Chen Previously I added a FIONREAD test for sockmap, but it can occasionally fail in CI [1]. The test sends 10 bytes in two segments (2 + 8). For UDP, FIONREAD only reports the length of the first datagram, not the total queued data. The original code used recv_timeout() expecting all 10 bytes, but under high system load, the second datagram may not yet be processed by the protocol stack, so recv would only return the first 2-byte datagram, causing a size mismatch failure. Fix this by receiving exactly the expected bytes (matching FIONREAD) in the first recv. The remaining datagram is then consumed in a second recv block, which is only reachable for UDP since TCP's expected already equals sizeof(buf). Test: ./test_progs -a sockmap_basic 410/1 sockmap_basic/sockmap create_update_free:OK ... Summary: 1/35 PASSED, 0 SKIPPED, 0 FAILED [1] https://github.com/kernel-patches/bpf/actions/runs/22919385910/job/66515395423 Cc: Jiayuan Chen Fixes: 17e2ce02bf56 ("selftests/bpf: Add tests for FIONREAD and copied_seq") Signed-off-by: Jiayuan Chen --- .../selftests/bpf/prog_tests/sockmap_basic.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c index dd3c757859f6b..d2846579285f2 100644 --- a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c +++ b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c @@ -1298,10 +1298,23 @@ static void test_sockmap_multi_channels(int sotype) avail = wait_for_fionread(p1, expected, IO_TIMEOUT_SEC); ASSERT_EQ(avail, expected, "ioctl(FIONREAD) full return"); - recvd = recv_timeout(p1, rcv, sizeof(rcv), MSG_DONTWAIT, 1); - if (!ASSERT_EQ(recvd, sizeof(buf), "recv_timeout(p1)") || + recvd = recv_timeout(p1, rcv, expected, MSG_DONTWAIT, 1); + if (!ASSERT_EQ(recvd, expected, "recv_timeout(p1)") || !ASSERT_OK(memcmp(buf, rcv, recvd), "data mismatch")) goto end; + + /* process remaining data for udp if secondary data is available */ + expected = sizeof(buf) - expected; + if (expected) { + avail = wait_for_fionread(p1, expected, IO_TIMEOUT_SEC); + ASSERT_EQ(avail, expected, "second ioctl(FIONREAD) full return"); + + recvd = recv_timeout(p1, rcv, expected, MSG_DONTWAIT, 1); + if (!ASSERT_EQ(recvd, expected, "second recv_timeout(p1)") || + !ASSERT_OK(memcmp(buf + sizeof(buf) - expected, rcv, recvd), + "second data mismatch")) + goto end; + } end: if (c0 >= 0) close(c0); -- 2.43.0