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#53136: 28.0.90; segfault in lock_file Date: Sun, 09 Jan 2022 10:42:07 +0200 Message-ID: <838rvp2tcw.fsf@gnu.org> References: <871r1hv40o.fsf.ref@yahoo.com> <871r1hv40o.fsf@yahoo.com> <83bl0l2we3.fsf@gnu.org> <87r19htjlp.fsf@yahoo.com> Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="24691"; mail-complaints-to="usenet@ciao.gmane.io" Cc: 53136@debbugs.gnu.org To: Po Lu Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Sun Jan 09 09:43:12 2022 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 1n6TnC-0006Fs-W9 for geb-bug-gnu-emacs@m.gmane-mx.org; Sun, 09 Jan 2022 09:43:11 +0100 Original-Received: from localhost ([::1]:58846 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1n6TnB-0008SM-Gg for geb-bug-gnu-emacs@m.gmane-mx.org; Sun, 09 Jan 2022 03:43:09 -0500 Original-Received: from eggs.gnu.org ([209.51.188.92]:50148) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1n6Tn4-0008S4-O6 for bug-gnu-emacs@gnu.org; Sun, 09 Jan 2022 03:43:02 -0500 Original-Received: from debbugs.gnu.org ([209.51.188.43]:56266) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1n6Tn4-000120-Fc for bug-gnu-emacs@gnu.org; Sun, 09 Jan 2022 03:43:02 -0500 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1n6Tn4-0006Lp-E0 for bug-gnu-emacs@gnu.org; Sun, 09 Jan 2022 03:43:02 -0500 X-Loop: help-debbugs@gnu.org Resent-From: Eli Zaretskii Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Sun, 09 Jan 2022 08:43:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 53136 X-GNU-PR-Package: emacs Original-Received: via spool by 53136-submit@debbugs.gnu.org id=B53136.164171774624353 (code B ref 53136); Sun, 09 Jan 2022 08:43:02 +0000 Original-Received: (at 53136) by debbugs.gnu.org; 9 Jan 2022 08:42:26 +0000 Original-Received: from localhost ([127.0.0.1]:49164 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1n6TmU-0006Ki-9H for submit@debbugs.gnu.org; Sun, 09 Jan 2022 03:42:26 -0500 Original-Received: from eggs.gnu.org ([209.51.188.92]:49382) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1n6TmS-0006KU-Pd for 53136@debbugs.gnu.org; Sun, 09 Jan 2022 03:42:25 -0500 Original-Received: from [2001:470:142:3::e] (port=50992 helo=fencepost.gnu.org) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1n6TmN-000107-GS; Sun, 09 Jan 2022 03:42:19 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=gnu.org; s=fencepost-gnu-org; h=References:Subject:In-Reply-To:To:From:Date: mime-version; bh=mki2uPn5hMlEVn3rfnlkZJxF1nD/ISe6AArwSoomN6Y=; b=MbmzgxCL7Evv DAhbznOK2BpJNy2MFd4JRWfPR9f0ATqXd1/WPZR3KA7UcqYf9Cv+CU79h8DfxG1M+2yulM1KM/TCY xdljbMFVTjin3T5G2k9p0FKjFojhaplgFAbLd9l2liNBmxzSGdVac4c3pwCRHEfsUeL7IodAAWGyi AJsscn/1HRs92zw6+nCFv8nLmrsI1EFS9whJIOZ6reph/INOuQAGZuIxwGrOiWPJ92OqIuiACBkR8 1RZSkkUgJhSHQAEqUDPHUytjvnuOfTeRLERNeSVpHIJbacPYFGiUivacdN2FIoycSsQbO9p2HhLX4 Z1a25RWwbYty/7fFpjAqcQ==; Original-Received: from [87.69.77.57] (port=4520 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 1n6TmN-00006u-Gu; Sun, 09 Jan 2022 03:42:19 -0500 In-Reply-To: <87r19htjlp.fsf@yahoo.com> (message from Po Lu on Sun, 09 Jan 2022 16:10:42 +0800) 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:223834 Archived-At: > From: Po Lu > Cc: 53136@debbugs.gnu.org > Date: Sun, 09 Jan 2022 16:10:42 +0800 > > >> memcpy (dot, replacement, replacementlen); > >> > >> Ends up writing one byte outside dot. > >> > >> I could not find the problem, but someone else may want to take a look. > > > Details, please: the values of all the relevant variables at that > > point, including the contents of all the string variables. > > gdb says dot is "optimized out" (but valgrind, which I happened to be > running that Emacs under in an attempt to catch the GC bug I reported a > month ago, disagrees). pidlen is 6. > > I will try to get more information from the valgrind core file. Thanks. > > And what is your value of MAX_LFINFO? > > MAX_LFINFO is 8192. So we somehow wrote more than 8192 bytes by that memcpy line? I find this hard to believe. What exactly did valgrind say?