Return-path: Received: from mail-wr0-f195.google.com ([209.85.128.195]:37008 "EHLO mail-wr0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1033540AbeE1P3N (ORCPT ); Mon, 28 May 2018 11:29:13 -0400 Received: by mail-wr0-f195.google.com with SMTP id i12-v6so20904788wrc.4 for ; Mon, 28 May 2018 08:29:12 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: References: <1527493857-2220-1-git-send-email-michael@amarulasolutions.com> <5B0BD13D.8000809@broadcom.com> From: Michael Nazzareno Trimarchi Date: Mon, 28 May 2018 17:29:11 +0200 Message-ID: (sfid-20180528_172956_253486_C1CA10C3) Subject: Re: [PATCH] brcmfmac: stop watchdog before detach and free everything To: Andy Shevchenko Cc: Arend van Spriel , Franky Lin , Hante Meuleman , Chi-Hsien Lin , Wright Feng , Kalle Valo , "David S. Miller" , Pieter-Paul Giesberts , Ian Molton , "open list:TI WILINK WIRELES..." , "open list:BROADCOM BRCM80211 IEEE802.11n WIRELESS DRIVER" , brcm80211-dev-list@cypress.com, netdev , LKML Content-Type: text/plain; charset="UTF-8" Sender: linux-wireless-owner@vger.kernel.org List-ID: Hi On Mon, May 28, 2018 at 5:25 PM, Andy Shevchenko wrote: > On Mon, May 28, 2018 at 12:54 PM, Michael Nazzareno Trimarchi > wrote: >> Hi Arend >> >> On Mon, May 28, 2018 at 11:51 AM, Arend van Spriel >> wrote: >>> On 5/28/2018 9:50 AM, Michael Trimarchi wrote: >>>> >>>> Watchdog need to be stopped in brcmf_sdio_remove to avoid >>>> i >>>> The system is going down NOW! >>>> [ 1348.110759] Unable to handle kernel NULL pointer dereference at virtual >>>> address 000002f8 >>>> Sent SIGTERM to all processes >>>> [ 1348.121412] Mem abort info: >>>> [ 1348.126962] ESR = 0x96000004 >>>> [ 1348.130023] Exception class = DABT (current EL), IL = 32 bits >>>> [ 1348.135948] SET = 0, FnV = 0 >>>> [ 1348.138997] EA = 0, S1PTW = 0 >>>> [ 1348.142154] Data abort info: >>>> [ 1348.145045] ISV = 0, ISS = 0x00000004 >>>> [ 1348.148884] CM = 0, WnR = 0 >>>> [ 1348.151861] user pgtable: 4k pages, 48-bit VAs, pgdp = (____ptrval____) >>>> [ 1348.158475] [00000000000002f8] pgd=0000000000000000 >>>> [ 1348.163364] Internal error: Oops: 96000004 [#1] PREEMPT SMP >>>> [ 1348.168927] Modules linked in: ipv6 >>>> [ 1348.172421] CPU: 3 PID: 1421 Comm: brcmf_wdog/mmc0 Not tainted >>>> 4.17.0-rc5-next-20180517 #18 >>>> [ 1348.180757] Hardware name: Amarula A64-Relic (DT) >>>> [ 1348.185455] pstate: 60000005 (nZCv daif -PAN -UAO) >>>> [ 1348.190251] pc : brcmf_sdiod_freezer_count+0x0/0x20 >>>> [ 1348.195124] lr : brcmf_sdio_watchdog_thread+0x64/0x290 >>> >>> >>> Hi Michael, >>> >>> Thanks for the patch. In normal scenario the callstack looks like this: >>> >>> brcmf_sdio_remove() >>> -> brcmf_detach() >>> -> brcmf_bus_stop() >>> -> brcmf_sdio_bus_stop() >>> >>> In brcmf_sdio_bus_stop() the watchdog is terminated. So in what scenario did >>> you encounter this null pointer deref? >> >> Is this happen even when there is not wifi firmware? >> boot without any firmware in the filesystem and then trigger a reboot > > Something like the above I had noticed for a long (couple of kernel > releases?) time, but wasn't a big priority to me. > Though, I can test this on my side. > > P.S. I think rmmod or echo > unbind will trigger that as well. > Right now the module is compiled in the kernel. I can dig down tonight on this if needed Michael > -- > With Best Regards, > Andy Shevchenko -- | Michael Nazzareno Trimarchi Amarula Solutions BV | | COO - Founder Cruquiuskade 47 | | +31(0)851119172 Amsterdam 1018 AM NL | | [`as] http://www.amarulasolutions.com |