From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: =?utf-8?Q?Gerd_M=C3=B6llmann?= Newsgroups: gmane.emacs.devel Subject: Re: MPS: assertion failed: header_type (h) != IGC_OBJ_FWD Date: Tue, 16 Jul 2024 16:48:38 +0200 Message-ID: References: <86zfqhh2xv.fsf@gnu.org> <87msmhwhal.fsf@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="3666"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Cc: Eli Zaretskii , Paul Eggert , pipcet@protonmail.com, emacs-devel@gnu.org To: Helmut Eller Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Tue Jul 16 16:49:47 2024 Return-path: Envelope-to: ged-emacs-devel@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1sTjUx-0000rY-7f for ged-emacs-devel@m.gmane-mx.org; Tue, 16 Jul 2024 16:49:47 +0200 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sTjUD-0005OB-Fy; Tue, 16 Jul 2024 10:49:03 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sTjTv-0004jY-Uj for emacs-devel@gnu.org; Tue, 16 Jul 2024 10:48:44 -0400 Original-Received: from mail-ed1-x535.google.com ([2a00:1450:4864:20::535]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1sTjTu-0004Ht-9n; Tue, 16 Jul 2024 10:48:43 -0400 Original-Received: by mail-ed1-x535.google.com with SMTP id 4fb4d7f45d1cf-58b447c5112so829482a12.3; Tue, 16 Jul 2024 07:48:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1721141320; x=1721746120; darn=gnu.org; h=content-transfer-encoding:mime-version:user-agent:message-id:date :references:in-reply-to:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=+BfGC4FSy7ZDcDYawXF4Cv0osokuyYnf3xONa7brfow=; b=XEeJPoKTZP7Nf3HCPVs3ylJ0RgfMjTJ5GGjD1TyyCf8RzVnk/HAmvtJWbJqjoR4Dy+ MIFU9ZHRJbDl2Fj0oDfmRavzAQi25w1pY229DttAiYcMpRsAlmVfj0NHyzFSuZhxqAiz /DU4x/mSoV/IQNjhwse6rHwsS+dYcV6doNN0cfvBwqMcU6+3MQPCysSkuK2jak1uAeKw szxrSY9mqh+yXKfZS8sMJBlmjncqLuJIQx6ADueHf2vWC/WUXxz/JL3XoZlFf095DWVx bl92usdwDVFEeMqCqeWA3eqZidqJIKElLu/LHCSxTPlSXhX2hI+xiQvTAHlM6ixGoCet de8g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1721141320; x=1721746120; h=content-transfer-encoding:mime-version:user-agent:message-id:date :references:in-reply-to:subject:cc:to:from:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=+BfGC4FSy7ZDcDYawXF4Cv0osokuyYnf3xONa7brfow=; b=a5UTnsEpp4Mu4vaTYrAcwENXdo/QK6YXvtG+ZmFjFueqLLWx0YzH4jp1XsuCAqV+DN coTaCmoGpworyGH9atOEqxEitwx6Npr7f6jiUxrsUBfrO53TnaTbwlwkmQhaONnAimwn 10IuYKEpTyrNrIrTKHH7l9sc9jfJLOiMyeQEv3dYmS4keSGpzMiElWs2OWZWZgBFdb/P c1pmxdhkqcefvRn8sFNWZr5OPAm+6fSnfGJNGvb8t++2JR5QRU6pXnizfLmVMM4mBILK yoaw9kZMncXzlPzliFmdnrEApegFlfxRI+uPe+OV6MAvKf9oRl2L1b1SjAYIpTMs82dU VhOg== X-Forwarded-Encrypted: i=1; AJvYcCU2zuxwbtS85u1HxPkH/sIgSvDcYTPL0Jc0/p+NUWXyky2AUCocVuPeFUNbIO3+L3urkCFYHmEEboNVcwD3LOuYQWES X-Gm-Message-State: AOJu0YwhA6zUKRLUqe15toeS7e67ciMlhvpxTizY5A+bRSfoDA5AFfeo 12tBqSKA4za8PB8zcJYe7/FGHwYNdcRsTlO9hE34MZk/FaUydQRXqvhWuA== X-Google-Smtp-Source: AGHT+IFCmGwLFP8QxtmamQzahj8kBDWeimbaXLWWCN4IKGPCUGRvFQ3onDi7XnBvbZBdV1e0L0P9KA== X-Received: by 2002:a17:906:413:b0:a77:d773:54ec with SMTP id a640c23a62f3a-a79ea3d73edmr180420666b.8.1721141319920; Tue, 16 Jul 2024 07:48:39 -0700 (PDT) Original-Received: from pro2.fritz.box (p4fe3aae8.dip0.t-ipconnect.de. [79.227.170.232]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-a79bc5b83a5sm324219566b.76.2024.07.16.07.48.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 16 Jul 2024 07:48:39 -0700 (PDT) In-Reply-To: <87msmhwhal.fsf@gmail.com> (Helmut Eller's message of "Tue, 16 Jul 2024 16:19:30 +0200") Received-SPF: pass client-ip=2a00:1450:4864:20::535; envelope-from=gerd.moellmann@gmail.com; helo=mail-ed1-x535.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.devel:321710 Archived-At: Helmut Eller writes: > On Tue, Jul 16 2024, Gerd M=C3=B6llmann wrote: > >> That's probably a misunderstanding. I'm thinking about a block of memory >> containing references, and the alignment of these references, not the >> alignment of the block. >> >> Example with sizeof(int) =3D 4, and sizeof(void *) =3D 8 >> >> struct x >> { >> int x; >> struct Lisp_Symbol *s; >> }; >> >> What about the offset of x::s? > > That's not a problem because offsetof(struct x, s) =3D 8. There are 4 > bytes padding after x. A problem could be if an unaligned void* is cast > to a struct Lisp_Symbol*; let's hope that nobody does that. If you're right, and the same holds for the control stack and anything else a malloc'd block can contain, then we're safe. Since I don't know that for a fact, it's an invalid assumption for me, ATM. Let's see if it continues crashing.