From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.bugs Subject: bug#49261: Segfault during loadup Date: Sun, 11 Jul 2021 13:21:16 +0300 Message-ID: <83bl79b17n.fsf@gnu.org> References: <87o8bn7bie.fsf@gnus.org> <87zgv6vuon.fsf@gmx.de> <837di9lwbm.fsf@gnu.org> <87a6n5vuu4.fsf@gnus.org> <8735sqnmei.fsf@gnus.org> <87zguyf4ht.fsf@gmx.de> <87pmvum54p.fsf@gnus.org> <87v95mf2lj.fsf@gmx.de> <87pmvt3ob1.fsf@gnus.org> <83r1g9evoy.fsf@gnu.org> <83pmvtevgg.fsf@gnu.org> <87czrt3mj4.fsf@gnus.org> <878s2h3m1d.fsf@gnus.org> <874kd53lnl.fsf@gnus.org> <87zgux26ab.fsf@gnus.org> <87pmvt25uq.fsf@gnus.org> <87lf6h2294.fsf@gnus.org> <87h7h51x9y.fsf_-_@gnus.org> Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="20974"; mail-complaints-to="usenet@ciao.gmane.io" Cc: larsi@gnus.org, 49261@debbugs.gnu.org To: Paul Eggert Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Sun Jul 11 12:23:27 2021 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 1m2WcR-0005GO-2H for geb-bug-gnu-emacs@m.gmane-mx.org; Sun, 11 Jul 2021 12:23:27 +0200 Original-Received: from localhost ([::1]:48908 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1m2WcQ-00008D-3V for geb-bug-gnu-emacs@m.gmane-mx.org; Sun, 11 Jul 2021 06:23:26 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:44232) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1m2Wb5-0006ve-Vx for bug-gnu-emacs@gnu.org; Sun, 11 Jul 2021 06:22:04 -0400 Original-Received: from debbugs.gnu.org ([209.51.188.43]:50648) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1m2Wb4-0001lo-AC for bug-gnu-emacs@gnu.org; Sun, 11 Jul 2021 06:22:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1m2Wb4-0002cH-5B for bug-gnu-emacs@gnu.org; Sun, 11 Jul 2021 06:22:02 -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, 11 Jul 2021 10:22:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 49261 X-GNU-PR-Package: emacs Original-Received: via spool by 49261-submit@debbugs.gnu.org id=B49261.162599889310023 (code B ref 49261); Sun, 11 Jul 2021 10:22:02 +0000 Original-Received: (at 49261) by debbugs.gnu.org; 11 Jul 2021 10:21:33 +0000 Original-Received: from localhost ([127.0.0.1]:33961 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1m2Wab-0002ba-DV for submit@debbugs.gnu.org; Sun, 11 Jul 2021 06:21:33 -0400 Original-Received: from eggs.gnu.org ([209.51.188.92]:46378) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1m2WaZ-0002bL-5N for 49261@debbugs.gnu.org; Sun, 11 Jul 2021 06:21:31 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]:41552) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1m2WaT-0001OO-6Q; Sun, 11 Jul 2021 06:21:25 -0400 Original-Received: from 84.94.185.95.cable.012.net.il ([84.94.185.95]:1774 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1m2WaS-0001We-Q0; Sun, 11 Jul 2021 06:21:25 -0400 In-Reply-To: (message from Paul Eggert on Sun, 11 Jul 2021 01:36:21 -0700) 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:209791 Archived-At: > Cc: 49261@debbugs.gnu.org, Eli Zaretskii > From: Paul Eggert > Date: Sun, 11 Jul 2021 01:36:21 -0700 > > I worked around this particular problem changing mark_maybe_pointer so > that pdumper roots can also be tagged (see first attached patch). > However, I suspect this is not a complete fix, as it doesn't cover the > case where a root points to some part of a pdumper object that is not at > the object's start. I added a FIXME about this. Perhaps Daniel can take > a look at it sometime. I think the remaining bug will be hit only rarely > (if ever). > > The second attached patch is in the same area, but is not part of the > fix. It causes the GC to be a bit more accurate (i.e., less > conservative) for roots, which can help avoid some leaks. Thanks, but these changes don't cater to 32-bit builds --with-wide-int: CC alloc.o In file included from alloc.c:33: alloc.c: In function 'mark_maybe_pointer': lisp.h:251:18: warning: unsigned conversion from 'long long int' to 'uintptr_t' {aka 'unsigned int'} changes value from '2305843009213693951' to '4294967295' [-Woverflow] 251 | # define VALMASK (USE_LSB_TAG ? - (1 << GCTYPEBITS) : VAL_MAX) | ^ alloc.c:4767:24: note: in expansion of macro 'VALMASK' 4767 | uintptr_t mask = VALMASK; | ^~~~~~~