From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ot1-f53.google.com (mail-ot1-f53.google.com [209.85.210.53]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 48D7B23EABC for ; Wed, 8 Apr 2026 19:11:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.53 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775675483; cv=none; b=ccGlGZO9amQjhvYMSCStKATHPYmecuKGXqkqajDrD+o1ytxCCpEfRPwycfPRUuOajgBprA0bXwCPLVLS3hqsxNNHnKdUeH4554ZzkeryiUtRycKtL1nnvP1O3GUBWc9sIMqhrJH2PlAUEjOIUkjnPuQFzMQo0LgB/TCJ8A9sjzM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775675483; c=relaxed/simple; bh=QywkMKt9HfbdvydAmCDLA/mewW0A3C9JQlo+MYVYw00=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=qLxEFyLMWe2bkJiXQGC1QbCKbD3GzHUqBpp4WRaTEDUF8VDuAS3gxOI1t4SsiIawnr69yKyu/sD/HscG9zS9YNAJiPQfnsDoQ9+cFWvAYBI/ullKg3TU26stS/dS6aj4kKnHpv7LNHx+sZvYE0vaaPSqRtLtZ/SbtLy6FuDF6Hs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=cloudflare.com; spf=pass smtp.mailfrom=cloudflare.com; dkim=pass (2048-bit key) header.d=cloudflare.com header.i=@cloudflare.com header.b=LMZm0HzU; arc=none smtp.client-ip=209.85.210.53 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=cloudflare.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=cloudflare.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=cloudflare.com header.i=@cloudflare.com header.b="LMZm0HzU" Received: by mail-ot1-f53.google.com with SMTP id 46e09a7af769-7dbec19732eso113556a34.3 for ; Wed, 08 Apr 2026 12:11:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cloudflare.com; s=google09082023; t=1775675481; x=1776280281; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=NWlPCpaM6YJiK7lQXjNJIiFwkV0uyI0s2T5X9GR48qE=; b=LMZm0HzU/Z9SjWgXYja7mHAMOwVclB5jDfApGeJ+EmAA1/4et5n3Gdsnepy3LhVAa4 8NIMgRmIcfmQJ65eVT0VdqawlOKRxNKsZ9Mi5jbsX1C+BnL4DCkpnB7RJY0oOd6H8UCi mtY4aivM6iNdMeLZ+IEAzxeaAvx/SArWJWXyMRttgb9U5n1buDepbwmZWzRlg1FXQkPZ K86JN+JCLdn5L3hC/ZP3ukMl+UXSweRxMrmSh9QAmKKfd0KBnRDfg86zRfWBGfYI+mRJ f6XzoQzxZluXmrPBK6pltuLe35BuWoZ47ndnLxUzu1nXyM2YmYgMNnmBbAgOJONy6FOs 8O2w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1775675481; x=1776280281; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=NWlPCpaM6YJiK7lQXjNJIiFwkV0uyI0s2T5X9GR48qE=; b=VJI0I76/DXMOW46Kp1Q/sI6MwW9fsNl9i/rrPJSMEbvsy/c+KoJdtlRINF/eGAJD6B AzeBf1He/wkl8VBRnbpdMkfkTdeSh3pVoCoVZDDYLfcj3pWoQLCxhUwI+TuLjd0ID+sS dRZ08cOyb7jH6dYXKxFjHby7mqk6SCS69WrECJQ6FE6a8IsPeGOMWL2k9kYo5UjF/ruz MgpsOPwFB4rzCS3CEA3oB+xzmYBrxY3QcJHxaK4YygQut+THTuwc/C5HlGEucEN11a4+ 6LfxjQ4WsVqI/+T8o5xc7UvI0v4rDfu17u3WZw2eRAFtrxkOP2R+37oG7ssTgValQXAk PJDA== X-Forwarded-Encrypted: i=1; AJvYcCX1otii0UnMXczLBslPinh2QwgQ0ssizr5sZVKiTc38F6wjgRzc/vluEu2WSa6ulSrn/pwP37uYWP3Y52A=@vger.kernel.org X-Gm-Message-State: AOJu0Yysb7/FZE45eORzsaqTq1Px4gOkNgxnegW3YuAlM0aNWDCSSyP5 r0AG6J3O9PVRko0CzCyQrA6zBVbm4f4OXnjBLn72T3smK31u26HT5FudtBj088fXnShyNquf2kS Ye7jCqrboSQ== X-Gm-Gg: AeBDieu0ichrjy0teC/51pq2/xPEt6ktXwhbk2Pi0YYvKMPXCZmvn1ZKlGr5HU3dyTt iGMAZ5wg24VZ/W8d0kWr2dQYhllKaeRyIqoAXhwRK9rjoNhYqaqtROJqWOfqfZWFGuNXFstNMQ2 31oIzWnwG0pjPOhOHdJYnvCUopvZD6DluK4oUOvSzehkJ/cL1ToAOTX68DUEX48mjF25Ga+Dnfr P+Mqi+o+imafC6O/bWj+vdt4ssUkxC9Xw1vP7MErVqBaA72frk74yCEghExYp7XpIJv5LCE7TD7 lOjG8xV16PQRj8ARk7t/NSUA3utEYuCeDo8Vm5/sTNDl/6Uh9Jw5ttdOOv3e8RGUgWzKC2CnGgB MjhoYvTc+pEAyxPZXTDZ0REgJNHd93riTaTbqg/nzfZQQNHcCa1IDomYm7clhLk0B6x1h/3V/jy 9+cmggxOysSQ== X-Received: by 2002:a05:6830:2aa5:b0:7d7:cc2f:babb with SMTP id 46e09a7af769-7dbb72f9c3fmr16664921a34.2.1775675481129; Wed, 08 Apr 2026 12:11:21 -0700 (PDT) Received: from 20HS2G4.. ([2a09:bac6:bf21:2e28::499:49]) by smtp.gmail.com with ESMTPSA id 46e09a7af769-7dc098578c3sm1979035a34.25.2026.04.08.12.11.20 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 08 Apr 2026 12:11:20 -0700 (PDT) From: Chris J Arges To: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , David Ahern Cc: kernel-team@cloudflare.com, Chris J Arges , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH net-next v2] net: Add net_cookie to Dead loop messages Date: Wed, 8 Apr 2026 14:10:47 -0500 Message-ID: <20260408191056.1036330-1-carges@cloudflare.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Network devices can have the same name within different network namespaces. To help distinguish these devices, add the net_cookie value which can be used to identify the netns. Signed-off-by: Chris J Arges --- v2: rebased on net-next --- net/core/dev.c | 5 +++-- net/ipv4/ip_tunnel_core.c | 4 ++-- 2 files changed, 5 insertions(+), 4 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index 5a31f9d2128c..3c752ba3aa29 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4886,8 +4886,9 @@ int __dev_queue_xmit(struct sk_buff *skb, struct net_device *sb_dev) } else { /* Recursion is detected! It is possible unfortunately. */ recursion_alert: - net_crit_ratelimited("Dead loop on virtual device %s, fix it urgently!\n", - dev->name); + net_crit_ratelimited("Dead loop on virtual device %s (net %llu), fix it urgently!\n", + dev->name, dev_net(dev)->net_cookie); + rc = -ENETDOWN; } diff --git a/net/ipv4/ip_tunnel_core.c b/net/ipv4/ip_tunnel_core.c index f430d6f0463e..2667f53482bd 100644 --- a/net/ipv4/ip_tunnel_core.c +++ b/net/ipv4/ip_tunnel_core.c @@ -60,8 +60,8 @@ void iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb, if (unlikely(dev_recursion_level() > IP_TUNNEL_RECURSION_LIMIT)) { if (dev) { - net_crit_ratelimited("Dead loop on virtual device %s, fix it urgently!\n", - dev->name); + net_crit_ratelimited("Dead loop on virtual device %s (net %llu), fix it urgently!\n", + dev->name, dev_net(dev)->net_cookie); DEV_STATS_INC(dev, tx_errors); } ip_rt_put(rt); -- 2.43.0