From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.ciao.gmane.io!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.bugs Subject: bug#41321: 27.0.91; Emacs aborts due to invalid pseudovector objects Date: Sun, 24 May 2020 17:24:41 +0300 Message-ID: <83h7w5xvfa.fsf@gnu.org> References: <83zha8cgpi.fsf@gnu.org> <83r1vibmyj.fsf@gnu.org> <83imgublku.fsf@gnu.org> <831rncjuwf.fsf@gnu.org> Injection-Info: ciao.gmane.io; posting-host="ciao.gmane.io:159.69.161.202"; logging-data="101261"; mail-complaints-to="usenet@ciao.gmane.io" Cc: 41321@debbugs.gnu.org, monnier@iro.umontreal.ca To: Pip Cet Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Sun May 24 16:25:10 2020 Return-path: Envelope-to: geb-bug-gnu-emacs@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 1jcrYs-000QDY-6A for geb-bug-gnu-emacs@m.gmane-mx.org; Sun, 24 May 2020 16:25:10 +0200 Original-Received: from localhost ([::1]:43784 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jcrYq-0004rm-UQ for geb-bug-gnu-emacs@m.gmane-mx.org; Sun, 24 May 2020 10:25:08 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:43582) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jcrYk-0004r4-Ex for bug-gnu-emacs@gnu.org; Sun, 24 May 2020 10:25:02 -0400 Original-Received: from debbugs.gnu.org ([209.51.188.43]:55104) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1jcrYk-000692-66 for bug-gnu-emacs@gnu.org; Sun, 24 May 2020 10:25:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1jcrYk-0007lj-3G for bug-gnu-emacs@gnu.org; Sun, 24 May 2020 10:25:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Eli Zaretskii Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Sun, 24 May 2020 14:25:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 41321 X-GNU-PR-Package: emacs Original-Received: via spool by 41321-submit@debbugs.gnu.org id=B41321.159033028329836 (code B ref 41321); Sun, 24 May 2020 14:25:02 +0000 Original-Received: (at 41321) by debbugs.gnu.org; 24 May 2020 14:24:43 +0000 Original-Received: from localhost ([127.0.0.1]:38417 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1jcrYR-0007l9-96 for submit@debbugs.gnu.org; Sun, 24 May 2020 10:24:43 -0400 Original-Received: from eggs.gnu.org ([209.51.188.92]:36132) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1jcrYQ-0007ky-3A for 41321@debbugs.gnu.org; Sun, 24 May 2020 10:24:42 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]:60876) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jcrYK-00066X-Q2; Sun, 24 May 2020 10:24:36 -0400 Original-Received: from [176.228.60.248] (port=4136 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1jcrYK-0007t9-95; Sun, 24 May 2020 10:24:36 -0400 In-Reply-To: (message from Pip Cet on Sat, 23 May 2020 23:54:17 +0000) X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: "bug-gnu-emacs" Xref: news.gmane.io gmane.emacs.bugs:180892 Archived-At: > From: Pip Cet > Date: Sat, 23 May 2020 23:54:17 +0000 > Cc: Stefan Monnier , 41321@debbugs.gnu.org > > I think I've worked it out: it's this mingw bug: > https://sourceforge.net/p/mingw-w64/bugs/778/ Thank you for working on this tricky problem. FTR, I don't use that flavor of MinGW. > On mingw, if is included before/instead of stddef.h, > alignof (max_align_t) == 16. The problem with the order of inclusion doesn't exist in my header files, so alignof (max_align_t) is always 16. > However, as can be seen by the backtrace > above, Eli's malloc only returned an 8-byte-aligned block. Isn't that strange? Lisp data is allocated via lmalloc, AFAIK, and lmalloc is supposed to guarantee LISP_ALIGNMENT alignment. Or am I missing something? > That's not normally a problem, because mark_maybe_object doesn't > care about alignment; but in conjunction with the gcc behavior > change, we rely or mark_maybe_pointer to mark the pointer, and it > doesn't, because the pointer is not aligned to a LISP_ALIGNMENT = > 16-byte boundary. I still very much doubt that this has anything to do with stack marking during GC, since I've shown in my backtrace that current_buffer->overlays_before points to an overlay with invalid markers. And GC always marks buffer's overlays (and thus their markers), as can be seen in mark_buffer.