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 D288AC6FD1D for ; Sat, 1 Apr 2023 10:18:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229441AbjDAKSI (ORCPT ); Sat, 1 Apr 2023 06:18:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41350 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229379AbjDAKSH (ORCPT ); Sat, 1 Apr 2023 06:18:07 -0400 X-Greylist: delayed 381 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Sat, 01 Apr 2023 03:18:04 PDT Received: from mail-out.m-online.net (mail-out.m-online.net [IPv6:2001:a60:0:28:0:1:25:1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 699331C1C6 for ; Sat, 1 Apr 2023 03:18:04 -0700 (PDT) Received: from frontend01.mail.m-online.net (unknown [192.168.8.182]) by mail-out.m-online.net (Postfix) with ESMTP id 4PpXxl25jdz1s953; Sat, 1 Apr 2023 12:11:39 +0200 (CEST) Received: from localhost (dynscan1.mnet-online.de [192.168.6.70]) by mail.m-online.net (Postfix) with ESMTP id 4PpXxl0Vfdz1qqlW; Sat, 1 Apr 2023 12:11:39 +0200 (CEST) X-Virus-Scanned: amavisd-new at mnet-online.de Received: from mail.mnet-online.de ([192.168.8.182]) by localhost (dynscan1.mail.m-online.net [192.168.6.70]) (amavisd-new, port 10024) with ESMTP id l21SewfvkEMk; Sat, 1 Apr 2023 12:11:38 +0200 (CEST) X-Auth-Info: s0bblsSdvczRp0PoZO9CWlKKHtfOTkzM/6lVPhPwCxg0+nDMs1ahMapG5hcwOFWw Received: from igel.home (aftr-82-135-86-30.dynamic.mnet-online.de [82.135.86.30]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mail.mnet-online.de (Postfix) with ESMTPSA; Sat, 1 Apr 2023 12:11:38 +0200 (CEST) Received: by igel.home (Postfix, from userid 1000) id 103C52C1299; Sat, 1 Apr 2023 12:11:38 +0200 (CEST) From: Andreas Schwab To: Finn Thain Cc: debian-68k@lists.debian.org, linux-m68k@lists.linux-m68k.org Subject: Re: core dump analysis, was Re: stack smashing detected References: <4a9c1d0d-07aa-792e-921f-237d5a30fc44.ref@yahoo.com> <8042d988-6dd9-8170-60e9-cdf19118440f@yahoo.com> <37da2ca2-dd99-8417-7cae-a88e2e7fc1b6@yahoo.com> <30a1be59-a1fd-f882-1072-c7db8734b1f1@gmail.com> <39f79c2d-e803-d7b1-078f-8757ca9b1238@yahoo.com> <040ad66a-71dd-001b-0446-36cbd6547b37@yahoo.com> <5b9d64bb-2adc-20a2-f596-f99bf255b5cc@linux-m68k.org> <56bd9a33-c58a-58e0-3956-e63c61abe5fe@yahoo.com> <1725f7c1-2084-a404-653d-9e9f8bbe961c@linux-m68k.org> <19d1f2ac-67dd-5415-b64a-1e1b4451f01e@linux-m68k.org> X-Yow: Maybe we could paint GOLDIE HAWN a rich PRUSSIAN BLUE-- Date: Sat, 01 Apr 2023 12:11:38 +0200 In-Reply-To: (Finn Thain's message of "Sat, 1 Apr 2023 20:27:14 +1100 (AEDT)") Message-ID: <87zg7rap45.fsf@igel.home> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-m68k@vger.kernel.org On Apr 01 2023, Finn Thain wrote: > So, in summary, the canary validation failed in this case not because the > canary got clobbered but because %a3 got clobbered, somewhere between > __wait3+24 and __wait3+70 (below). > > The call to __GI___wait4_time64 causes %a3 to be saved to and restored > from the stack, so stack corruption seems to be a strong possibility to > explain the change in %a3. > > But if that's what happened, I'd expect __GI___wait4_time64 to report > stack smashing, not __wait3... The stask smashing probably didn't fire in __wait4_time64, because it hit the saved register area, not the canary (which reside on the opposite ends of the stack frame). -- Andreas Schwab, schwab@linux-m68k.org GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510 2552 DF73 E780 A9DA AEC1 "And now for something completely different."