From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from m16.mail.163.com (m16.mail.163.com [117.135.210.4]) (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 327E035C1A1; Tue, 29 Sep 2026 08:35:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=117.135.210.4 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790670949; cv=none; b=hAsRwW9uXIGge+9NxuK52fAhmHU30GEPfuuXsK1P+hFd7ixRXjjLaJ7mRT5MYhgpMd2jA9EPbTbKoK4DrdFnVT9e+6SgiGDbFWQyrj+n1aQexgJ8psDkdb2bLui/jAmKuxxyN6IhqNFhTnljfdri7XEkaK6KzGuqOF/2cVrgDkk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790670949; c=relaxed/simple; bh=ISprP6wPmA53c9jR3r5vxsxu0Q8W2yHrSj6Uko//BRs=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=pjpia1Dukj+eV/NDr8CYbNe2Gz3WfR/Ars7d7j/Kc/4Re/hH4toxzkA/5zF+OH/RFcxlp9VIkAJXp+Imvl5ggUFxQaxZOJgcUKxrKkxGD4hYjqG5GtUwLH1m/FDKLDEu+2H8XX8yW58HbLJYvpJ1LUx6oSlHRTOkcDWS1MLBqwQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com; spf=pass smtp.mailfrom=163.com; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b=T/3UYNOe; arc=none smtp.client-ip=117.135.210.4 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=163.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b="T/3UYNOe" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:To:Subject:Date:Message-ID:MIME-Version; bh=5r TbC2FHmDTljqlS8nFI14Yj+FpGBOm/RrUDuhusgyY=; b=T/3UYNOeZPS65RadYd tEIeF8M9xQQp7xfSMpCf2cWYYwBnZraDtfZCG/FFL9d+en/GgEnlz6GXXW8VSp5K IHbiVaXZf+ET1sn5QzdD/Q3BvQSm4cCFi3nK2XoxvqNx1cLJgAxDvi/5Y2vazMd8 ix0iiGhFOyWXWLqcgkImStupM= Received: from nec8-i7 (unknown []) by gzga-smtp-mtada-g1-0 (Coremail) with SMTP id _____wD3vx8seLtq177cBQ--.12081S2; Tue, 29 Sep 2026 16:34:54 +0800 (CST) From: chenyuan_fl@163.com To: netdev@vger.kernel.org, bpf@vger.kernel.org Cc: john.fastabend@gmail.com, jakub@cloudflare.com, jiayuan.chen@linux.dev, daniel@iogearbox.net, ast@kernel.org, cong.wang@bytedance.com, linux-kernel@vger.kernel.org Subject: [PATCH bpf-next 0/2] bpf, sockmap: Fix udp_bpf_recvmsg() spinning on backlog-only ingress Date: Tue, 29 Sep 2026 16:34:45 +0800 Message-ID: <20260929083447.558818-1-chenyuan_fl@163.com> X-Mailer: git-send-email 2.54.0 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CM-TRANSID:_____wD3vx8seLtq177cBQ--.12081S2 X-Coremail-Antispam: 1Uf129KBjvdXoWrury3Ary8GF48KryUWw1kGrg_yoWDGFX_uF W7tr97Jw4DJFn8KFWruFs5AFWFka1xKrZrKFWjvF17Wrs8trZ8ZF4vkr93Ja4rWayxJrW3 Jws5X34xKrWfXjkaLaAFLSUrUUUUjb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUvcSsGvfC2KfnxnUUI43ZEXa7IUb66z5UUUUU== X-CM-SenderInfo: xfkh05pxdqswro6rljoofrz/xtbDAg6ycGq7eC4quAAA3b From: Yuan Chen udp_bpf_recvmsg() re-arms its receive loop on backlog-only skbs that sk_msg_recvmsg() can never consume: whenever the backlog stays populated, the loop re-arms on the same skb forever and recvmsg() spins while holding the socket lock instead of sleeping. Patch 1 aligns the re-arm condition with TCP and unix_bpf_recvmsg(); patch 2 adds a selftest that reproduces the hang. Yuan Chen (2): bpf, sockmap: Fix udp_bpf_recvmsg() spinning on backlog-only ingress selftests/bpf: Add a test for udp_bpf_recvmsg() with a stuck backlog net/ipv4/udp_bpf.c | 2 +- .../bpf/prog_tests/sockmap_udp_backlog.c | 141 ++++++++++++++++++ .../bpf/progs/test_sockmap_udp_backlog.c | 21 +++ 3 files changed, 163 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/sockmap_udp_backlog.c create mode 100644 tools/testing/selftests/bpf/progs/test_sockmap_udp_backlog.c -- 2.54.0