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=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 B97CFC00A89 for ; Thu, 5 Nov 2020 11:03:49 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E26A22072E for ; Thu, 5 Nov 2020 11:03:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E26A22072E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.crashing.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 4CRgcc3xN5zDqxL for ; Thu, 5 Nov 2020 22:03:44 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=permerror (SPF Permanent Error: Unknown mechanism found: ip:192.40.192.88/32) smtp.mailfrom=kernel.crashing.org (client-ip=63.228.1.57; helo=gate.crashing.org; envelope-from=segher@kernel.crashing.org; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=kernel.crashing.org Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) by lists.ozlabs.org (Postfix) with ESMTP id 4CRgb44zPFzDqVq for ; Thu, 5 Nov 2020 22:02:24 +1100 (AEDT) Received: from gate.crashing.org (localhost.localdomain [127.0.0.1]) by gate.crashing.org (8.14.1/8.14.1) with ESMTP id 0A5B0Gla016486; Thu, 5 Nov 2020 05:00:16 -0600 Received: (from segher@localhost) by gate.crashing.org (8.14.1/8.14.1/Submit) id 0A5B0FXA016485; Thu, 5 Nov 2020 05:00:15 -0600 X-Authentication-Warning: gate.crashing.org: segher set sender to segher@kernel.crashing.org using -f Date: Thu, 5 Nov 2020 05:00:15 -0600 From: Segher Boessenkool To: Michael Ellerman Subject: Re: Kernel panic from malloc() on SUSE 15.1? Message-ID: <20201105110015.GY2672@gate.crashing.org> References: <878sbjuqe6.fsf@mpe.ellerman.id.au> <87lffgt8b9.fsf@mpe.ellerman.id.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87lffgt8b9.fsf@mpe.ellerman.id.au> User-Agent: Mutt/1.4.2.3i X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Carl Jacobsen , linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Thu, Nov 05, 2020 at 09:19:22PM +1100, Michael Ellerman wrote: > Carl Jacobsen writes: > This doesn't make a lot of sense. > > > Bad kernel stack pointer 7fffffffeac0 at 700 > > "at 700" is the regs->nip value, and suggests we're trying to handle a > program check, which is either a trap or BUG or WARN, or illegal > instruction or several other things. > > REGS: c00000001ec2fd40 TRAP: 0300 Tainted: G (4.12.14-197.18-default) > > But then here it says TRAP = 0x300, which is != 0x700. > > The trap number is hardcoded in the bad stack handling code, and I don't > see how we can end up with nip == 0x700 but the trap value == 0x300. > > > MSR: 8000000000001000 CR: 44000844 XER: 20000000 > > And here the MSR says you were in big endian mode, but you said before > your machine was ppc64le. It looks like you got a DSI (the 300), but for some reason that interrupt was not taken in LE mode, so the instruction at 300 was read as a lot of gobbledygook, not a valid insn, and the processor took a program interrupt (the 700). (MSR[RI]=0, but there can be other causes for that of course.) Segher