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[23.128.96.18]) by mx.google.com with ESMTP id 11si1895886edw.187.2021.08.13.06.49.31; Fri, 13 Aug 2021 06:49:55 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240071AbhHML7f (ORCPT + 99 others); Fri, 13 Aug 2021 07:59:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58608 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239888AbhHML72 (ORCPT ); Fri, 13 Aug 2021 07:59:28 -0400 Received: from ozlabs.org (ozlabs.org [IPv6:2401:3900:2:1::2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 25308C061756 for ; Fri, 13 Aug 2021 04:59:02 -0700 (PDT) Received: by ozlabs.org (Postfix, from userid 1034) id 4GmMXh1tNzz9t2b; Fri, 13 Aug 2021 21:59:00 +1000 (AEST) From: Michael Ellerman To: Michael Ellerman , Christophe Leroy , Benjamin Herrenschmidt , Paul Mackerras Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org In-Reply-To: <75287841cbb8740edd44880fe60be66d489160d9.1628097995.git.christophe.leroy@csgroup.eu> References: <75287841cbb8740edd44880fe60be66d489160d9.1628097995.git.christophe.leroy@csgroup.eu> Subject: Re: [PATCH] powerpc/smp: Fix OOPS in topology_init() Message-Id: <162885586726.2317031.18007540873140070843.b4-ty@ellerman.id.au> Date: Fri, 13 Aug 2021 21:57:47 +1000 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 4 Aug 2021 18:24:10 +0000 (UTC), Christophe Leroy wrote: > Running an SMP kernel on an UP platform not prepared for it, > I encountered the following OOPS: > > BUG: Kernel NULL pointer dereference on read at 0x00000034 > Faulting instruction address: 0xc0a04110 > Oops: Kernel access of bad area, sig: 11 [#1] > BE PAGE_SIZE=4K SMP NR_CPUS=2 CMPCPRO > Modules linked in: > CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.13.0-pmac-00001-g230fedfaad21 #5234 > NIP: c0a04110 LR: c0a040d8 CTR: c0a04084 > REGS: e100dda0 TRAP: 0300 Not tainted (5.13.0-pmac-00001-g230fedfaad21) > MSR: 00009032 CR: 84000284 XER: 00000000 > DAR: 00000034 DSISR: 20000000 > GPR00: c0006bd4 e100de60 c1033320 00000000 00000000 c0942274 00000000 00000000 > GPR08: 00000000 00000000 00000001 00000063 00000007 00000000 c0006f30 00000000 > GPR16: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000005 > GPR24: c0c67d74 c0c67f1c c0c60000 c0c67d70 c0c0c558 1efdf000 c0c00020 00000000 > NIP [c0a04110] topology_init+0x8c/0x138 > LR [c0a040d8] topology_init+0x54/0x138 > Call Trace: > [e100de60] [80808080] 0x80808080 (unreliable) > [e100de90] [c0006bd4] do_one_initcall+0x48/0x1bc > [e100def0] [c0a0150c] kernel_init_freeable+0x1c8/0x278 > [e100df20] [c0006f44] kernel_init+0x14/0x10c > [e100df30] [c00190fc] ret_from_kernel_thread+0x14/0x1c > Instruction dump: > 7c692e70 7d290194 7c035040 7c7f1b78 5529103a 546706fe 5468103a 39400001 > 7c641b78 40800054 80c690b4 7fb9402e <81060034> 7fbeea14 2c080000 7fa3eb78 > ---[ end trace b246ffbc6bbbb6fb ]--- > > [...] Applied to powerpc/fixes. [1/1] powerpc/smp: Fix OOPS in topology_init() https://git.kernel.org/powerpc/c/8241461536f21bbe51308a6916d1c9fb2e6b75a7 cheers