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 BBDA9C433EF for ; Fri, 27 May 2022 12:28:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348451AbiE0M2R (ORCPT ); Fri, 27 May 2022 08:28:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46948 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1355284AbiE0M1f (ORCPT ); Fri, 27 May 2022 08:27:35 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5398DA5; Fri, 27 May 2022 05:06:42 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 06BDCB824D8; Fri, 27 May 2022 12:06:41 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8554BC385A9; Fri, 27 May 2022 12:06:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1653653199; bh=fPR03DvN6aZCOlnsEZXaYA7hSzVMz0SsOW9oln+FOMg=; h=From:To:Cc:Subject:References:Date:In-Reply-To:From; b=F5r1R/3pIR8wIVp5nBZnJpKz9BS0ECMiDAdNrh5eEazvJH/fZeVNJu6UQ6933OaW3 803TrXtUatxRXokzpOrYNZMqxmyKEL22HN2Shvjff8FXu7H1Vr0F/Q51ZJyb4qbcYd aC4yuQdR5gxOb9PxCEaCuwI4Egq6/fAj1D87GVEpLxdO+oqBHWPBaE+t/rmfszV+eB jjmCkfN3EGo+uUExNnDFrLGbLYQn/I2fbrB9GugdN5G3cMTFkNrbm9AddEikKfbGav 4ByKTY6pRvYtNwj1yC1M/Mux+wQOBCWNAZ65n9YagKD/sNf29uWtbHwaIcM6bCBeIA i8y2lXJ9XnMGQ== From: Kalle Valo To: Johan Hovold Cc: Johan Hovold , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , ath11k@lists.infradead.org, linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [RFC] ath11k: fix netdev open race References: <20220517103436.15867-1-johan+linaro@kernel.org> <875ylwysoy.fsf@kernel.org> Date: Fri, 27 May 2022 15:06:35 +0300 In-Reply-To: (Johan Hovold's message of "Tue, 24 May 2022 09:26:23 +0200") Message-ID: <87mtf3p4c4.fsf@kernel.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Johan Hovold writes: > On Mon, May 23, 2022 at 10:06:37PM +0300, Kalle Valo wrote: >> Johan Hovold writes: >> >> > On Tue, May 17, 2022 at 12:34:36PM +0200, Johan Hovold wrote: >> >> Make sure to allocate resources needed before registering the device. >> >> >> >> This specifically avoids having a racing open() trigger a BUG_ON() in >> >> mod_timer() when ath11k_mac_op_start() is called before the >> >> mon_reap_timer as been set up. >> >> >> >> Fixes: d5c65159f289 ("ath11k: driver for Qualcomm IEEE 802.11ax devices") >> >> Fixes: 840c36fa727a ("ath11k: dp: stop rx pktlog before suspend") >> >> Signed-off-by: Johan Hovold >> >> --- >> > >> > For completeness: >> > >> > Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3 >> >> Thanks, added in the pending branch. >> >> You submitted this as RFC but do you mind if I apply this anyway? The >> patch looks good and passes my tests. But I do wonder why I haven't seen >> the crash... > > If it looks good to you then please do apply it. > > I was just worried that there may be some subtle reason for why > ath11k_dp_pdev_alloc() was called after netdev registration in the first > place and that it might need to be split up so that for example > ath11k_dp_rx_pdev_mon_attach() isn't called until after registration. At least I'm not aware of anything like that? Any comments from others? > I did not see this issue with next-20220310, but I hit it on every probe > with next-20220511. Perhaps some timing changed in between. > > Here's the backtrace for completeness in case someone else starts hitting > this and searches the archives: > > [ 51.346947] kernel BUG at kernel/time/timer.c:990! > [ 51.346958] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP > ... > [ 51.578225] Call trace: > [ 51.583293] __mod_timer+0x298/0x390 > [ 51.589518] mod_timer+0x14/0x20 > [ 51.595368] ath11k_mac_op_start+0x41c/0x4a0 [ath11k] > [ 51.603165] drv_start+0x38/0x60 [mac80211] > [ 51.610110] ieee80211_do_open+0x29c/0x7d0 [mac80211] > [ 51.617945] ieee80211_open+0x60/0xb0 [mac80211] > [ 51.625311] __dev_open+0x100/0x1c0 > [ 51.631420] __dev_change_flags+0x194/0x210 > [ 51.638214] dev_change_flags+0x24/0x70 > [ 51.644646] do_setlink+0x228/0xdb0 > [ 51.650723] __rtnl_newlink+0x460/0x830 > [ 51.657162] rtnl_newlink+0x4c/0x80 > [ 51.663229] rtnetlink_rcv_msg+0x124/0x390 > [ 51.669917] netlink_rcv_skb+0x58/0x130 > [ 51.676314] rtnetlink_rcv+0x18/0x30 > [ 51.682460] netlink_unicast+0x250/0x310 > [ 51.688960] netlink_sendmsg+0x19c/0x3e0 > [ 51.695458] ____sys_sendmsg+0x220/0x290 > [ 51.701938] ___sys_sendmsg+0x7c/0xc0 > [ 51.708148] __sys_sendmsg+0x68/0xd0 > [ 51.714254] __arm64_sys_sendmsg+0x28/0x40 > [ 51.720900] invoke_syscall+0x48/0x120 Thanks, this is good info and I added this to the commit log. -- https://patchwork.kernel.org/project/linux-wireless/list/ https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches