From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AD7ABC433FE for ; Thu, 10 Nov 2022 18:04:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231421AbiKJSEw (ORCPT ); Thu, 10 Nov 2022 13:04:52 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44454 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230490AbiKJSE0 (ORCPT ); Thu, 10 Nov 2022 13:04:26 -0500 Received: from out1-smtp.messagingengine.com (out1-smtp.messagingengine.com [66.111.4.25]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DF641262C for ; Thu, 10 Nov 2022 10:04:24 -0800 (PST) Received: from compute1.internal (compute1.nyi.internal [10.202.2.41]) by mailout.nyi.internal (Postfix) with ESMTP id 73B2C5C0176; Thu, 10 Nov 2022 13:04:21 -0500 (EST) Received: from mailfrontend1 ([10.202.2.162]) by compute1.internal (MEProxy); Thu, 10 Nov 2022 13:04:21 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-type:date:date:feedback-id :feedback-id:from:from:in-reply-to:in-reply-to:message-id :mime-version:references:reply-to:sender:subject:subject:to:to :x-me-proxy:x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s= fm1; t=1668103461; x=1668189861; bh=WA1sq4CfcZkPRhuimpm9jgjzigIW mcE4loajhOLSN3Y=; b=b5vc1fZBxobAPY1rsrs4anmVHP60Ql+ElGyoZJrT+3Y1 gXK6eDhDxSZ22bABN4neWnfS9u0SPoNEiv9+vtqKlXRzYXsZIJ5LkOVIu6fzp4OL rw4rkT+MDYCOY9an+tLF5hIgg9MesNbQoLJrvNJDHL75EUScJK8CRoxXPryj6IVn nayj5NkzRl7c7Q21goK4K4/AyG2119Em0A0ZnVtVQpQRoC0i/q8aStsy2Vn+C/k2 OWGygTErherZXgg7lwOztMjImnNZQqtSFnLx6co6JJXqqng2hNOTmyB7+1mErPKz DPv9FYq01yx+P/tNQ+bg3q8q9CQvh9GgK9bpuh23tQ== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvgedrfeeggddutdelucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmne cujfgurhepfffhvfevuffkfhggtggujgesthdtredttddtvdenucfhrhhomhepkfguohcu ufgthhhimhhmvghluceoihguohhstghhsehiughoshgthhdrohhrgheqnecuggftrfgrth htvghrnhephefhtdejvdeiffefudduvdffgeetieeigeeugfduffdvffdtfeehieejtdfh jeeknecuffhomhgrihhnpehkvghrnhgvlhdrohhrghenucevlhhushhtvghrufhiiigvpe dtnecurfgrrhgrmhepmhgrihhlfhhrohhmpehiughoshgthhesihguohhstghhrdhorhhg X-ME-Proxy: Feedback-ID: i494840e7:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Thu, 10 Nov 2022 13:04:17 -0500 (EST) Date: Thu, 10 Nov 2022 20:04:13 +0200 From: Ido Schimmel To: Eric Dumazet Cc: Jiri Pirko , Jakub Kicinski , netdev@vger.kernel.org, davem@davemloft.net, pabeni@redhat.com, bigeasy@linutronix.de, imagedong@tencent.com, kuniyu@amazon.com, petrm@nvidia.com Subject: Re: [patch net-next v2 3/3] net: devlink: add WARN_ON to check return value of unregister_netdevice_notifier_net() call Message-ID: References: <20221108132208.938676-1-jiri@resnulli.us> <20221108132208.938676-4-jiri@resnulli.us> <20221109134536.447890fb@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Thu, Nov 10, 2022 at 09:21:23AM -0800, Eric Dumazet wrote: > On Wed, Nov 9, 2022 at 11:54 PM Jiri Pirko wrote: > > > > Wed, Nov 09, 2022 at 10:45:36PM CET, kuba@kernel.org wrote: > > >On Wed, 9 Nov 2022 08:26:10 -0800 Eric Dumazet wrote: > > >> > On Tue, Nov 08, 2022 at 02:22:08PM +0100, Jiri Pirko wrote: > > >> > > From: Jiri Pirko > > >> > > > > >> > > As the return value is not 0 only in case there is no such notifier > > >> > > block registered, add a WARN_ON() to yell about it. > > >> > > > > >> > > Suggested-by: Ido Schimmel > > >> > > Signed-off-by: Jiri Pirko > > >> > > > >> > Reviewed-by: Ido Schimmel > > >> > > >> Please consider WARN_ON_ONCE(), or DEBUG_NET_WARN_ON_ONCE() > > > > > >Do you have any general guidance on when to pick WARN() vs WARN_ONCE()? > > >Or should we always prefer _ONCE() going forward? > > > > Good question. If so, it should be documented or spotted by checkpatch. > > > > > > > >Let me take the first 2 in, to lower the syzbot volume. > > Well, I am not sure what you call 'lower syzbot volume' > > netdevsim netdevsim0 netdevsim3 (unregistering): unset [1, 0] type 2 > family 0 port 6081 - 0 > ------------[ cut here ]------------ > WARNING: CPU: 1 PID: 41 at net/core/devlink.c:10001 > devl_port_unregister+0x2f6/0x390 net/core/devlink.c:10001 Hi Eric, That's a different bug than the one fixed by this patchset. Should be fixed by this patch: https://patchwork.kernel.org/project/netdevbpf/patch/20221110085150.520800-1-idosch@nvidia.com/ > Modules linked in: > CPU: 0 PID: 41 Comm: kworker/u4:2 Not tainted > 6.1.0-rc3-syzkaller-00887-g0c9ef08a4d0f #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, > BIOS Google 10/26/2022 > Workqueue: netns cleanup_net > RIP: 0010:devl_port_unregister+0x2f6/0x390 net/core/devlink.c:10001 > Code: e8 3f 37 0b fa 85 ed 0f 85 7a fd ff ff e8 62 3a 0b fa 0f 0b e9 > 6e fd ff ff e8 56 3a 0b fa 0f 0b e9 53 ff ff ff e8 4a 3a 0b fa <0f> 0b > e9 94 fd ff ff e8 ae ac 57 fa e9 78 ff ff ff e8 74 ac 57 fa > RSP: 0018:ffffc90000b27a08 EFLAGS: 00010293 > RAX: 0000000000000000 RBX: ffff88806ee3f810 RCX: 0000000000000000 > RDX: ffff8880175e1d40 RSI: ffffffff877177d6 RDI: 0000000000000005 > RBP: 0000000000000002 R08: 0000000000000005 R09: 0000000000000000 > R10: 0000000000000002 R11: 0000000000000000 R12: ffff88806ee3f810 > R13: ffff88806ee3f808 R14: ffff88806ee3e800 R15: ffff88806ee3f800 > FS: 0000000000000000(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 000000c00023dee0 CR3: 0000000074faf000 CR4: 00000000003506f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > > __nsim_dev_port_del+0x1bb/0x240 drivers/net/netdevsim/dev.c:1433 > nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1443 [inline] > nsim_dev_reload_destroy+0x171/0x510 drivers/net/netdevsim/dev.c:1660 > nsim_dev_reload_down+0x6b/0xd0 drivers/net/netdevsim/dev.c:968 > devlink_reload+0x1c4/0x6e0 net/core/devlink.c:4501 > devlink_pernet_pre_exit+0x104/0x1c0 net/core/devlink.c:12615 > ops_pre_exit_list net/core/net_namespace.c:159 [inline] > cleanup_net+0x451/0xb10 net/core/net_namespace.c:594 > process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289 > worker_thread+0x665/0x1080 kernel/workqueue.c:2436 > kthread+0x2e4/0x3a0 kernel/kthread.c:376 > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 >