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 X-Spam-Level: X-Spam-Status: No, score=-5.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 675E5ECE587 for ; Mon, 14 Oct 2019 16:15:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 49CED20854 for ; Mon, 14 Oct 2019 16:15:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387999AbfJNQPL (ORCPT ); Mon, 14 Oct 2019 12:15:11 -0400 Received: from foss.arm.com ([217.140.110.172]:48080 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730028AbfJNQPK (ORCPT ); Mon, 14 Oct 2019 12:15:10 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 1DE8528; Mon, 14 Oct 2019 09:15:10 -0700 (PDT) Received: from [10.1.196.105] (eglon.cambridge.arm.com [10.1.196.105]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 32DAA3F718; Mon, 14 Oct 2019 09:15:09 -0700 (PDT) Subject: Re: edac KASAN warning in experimental arm64 allmodconfig boot To: John Garry Cc: Borislav Petkov , Mauro Carvalho Chehab , tony.luck@intel.com, Robert Richter , linux-edac@vger.kernel.org, "linux-kernel@vger.kernel.org" References: <304df85b-8b56-b77e-1a11-aa23769f2e7c@huawei.com> From: James Morse Message-ID: Date: Mon, 14 Oct 2019 17:15:05 +0100 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <304df85b-8b56-b77e-1a11-aa23769f2e7c@huawei.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi John, On 14/10/2019 16:18, John Garry wrote: > I'm experimenting by trying to boot an allmodconfig arm64 kernel, as mentioned here: Crumbs! > One thing that I noticed - it's hard to miss actually - is the amount of complaining from > KASAN about the EDAC/ghes code. Maybe this is something I should not care about/red > herring, or maybe something genuine. Let me know what you think. Hmmm, I thought I tested this recently... > Log snippet (I cut off after the first KASAN warning): > > [   70.471011][    T1] random: get_random_u32 called from new_slab+0x360/0x698 with > crng_init=0 > [   70.478671][    T1] [Firmware Bug]: APEI: Invalid bit width + offset in GAR > [0x94110034/64/0/3/0] (this one's for you right?) > [   70.700412][    T1] ------------[ cut here ]------------ > [   70.802080][    T1] Call trace: > [   70.802093][    T1]  debug_print_object+0xec/0x130 > [   70.802106][    T1]  __debug_check_no_obj_freed+0x114/0x290 > [   70.802119][    T1]  debug_check_no_obj_freed+0x18/0x28 > [   70.802130][    T1]  slab_free_freelist_hook+0x18c/0x228 > [   70.802140][    T1]  kfree+0x264/0x420 > [   70.802157][    T1]  _edac_mc_free+0x6c/0x210 > [   70.814163][    T1]  edac_mc_free+0x68/0x88 > [   70.814177][    T1]  ghes_edac_unregister+0x44/0x70 > [   70.814193][    T1]  ghes_remove+0x274/0x2a0 Ugh. This must be the test driver remove thing. I've reproduced this, but had to remove the parent GHES twice. It looks like it tries to use the first ghes_edac global variables when freeing the second. ghes_init prevents it from re-allocating over the top. The below diff fixes it for me. (I'll post it as a proper patch once I've done the archaeology) -----------%<----------- diff --git a/drivers/edac/ghes_edac.c b/drivers/edac/ghes_edac.c index d413a0bdc9ad..955b59b6aade 100644 --- a/drivers/edac/ghes_edac.c +++ b/drivers/edac/ghes_edac.c @@ -554,6 +554,7 @@ void ghes_edac_unregister(struct ghes *ghes) return; mci = ghes_pvt->mci; + ghes_pvt = NULL; edac_mc_del_mc(mci->pdev); edac_mc_free(mci); } -----------%<----------- Thanks! James