From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Paul Eggert Newsgroups: gmane.emacs.bugs Subject: bug#33174: 27.0.50; Dump fails on GNU/Linux ppc64le Date: Mon, 29 Oct 2018 00:22:15 -0700 Organization: UCLA Computer Science Department Message-ID: <39df62a1-58fb-0e5c-88a6-3eaae4e865d4@cs.ucla.edu> References: NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-Trace: blaine.gmane.org 1540797665 26923 195.159.176.226 (29 Oct 2018 07:21:05 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Mon, 29 Oct 2018 07:21:05 +0000 (UTC) User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.2.1 Cc: 33174@debbugs.gnu.org To: Thomas Fitzsimmons Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Mon Oct 29 08:21:01 2018 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1gH1rA-0006rS-So for geb-bug-gnu-emacs@m.gmane.org; Mon, 29 Oct 2018 08:21:00 +0100 Original-Received: from localhost ([::1]:43914 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gH1tH-0007hQ-8n for geb-bug-gnu-emacs@m.gmane.org; Mon, 29 Oct 2018 03:23:11 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:52258) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gH1tB-0007bw-P1 for bug-gnu-emacs@gnu.org; Mon, 29 Oct 2018 03:23:06 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gH1t8-0004OI-Km for bug-gnu-emacs@gnu.org; Mon, 29 Oct 2018 03:23:05 -0400 Original-Received: from debbugs.gnu.org ([208.118.235.43]:45624) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1gH1t8-0004Nz-GG for bug-gnu-emacs@gnu.org; Mon, 29 Oct 2018 03:23:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1gH1t8-0000xt-Bk for bug-gnu-emacs@gnu.org; Mon, 29 Oct 2018 03:23:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Paul Eggert Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Mon, 29 Oct 2018 07:23:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 33174 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: Original-Received: via spool by 33174-submit@debbugs.gnu.org id=B33174.15407977443643 (code B ref 33174); Mon, 29 Oct 2018 07:23:02 +0000 Original-Received: (at 33174) by debbugs.gnu.org; 29 Oct 2018 07:22:24 +0000 Original-Received: from localhost ([127.0.0.1]:49882 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1gH1sW-0000wh-JG for submit@debbugs.gnu.org; Mon, 29 Oct 2018 03:22:24 -0400 Original-Received: from zimbra.cs.ucla.edu ([131.179.128.68]:50390) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1gH1sV-0000wU-4N for 33174@debbugs.gnu.org; Mon, 29 Oct 2018 03:22:23 -0400 Original-Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id CD43C16005E; Mon, 29 Oct 2018 00:22:16 -0700 (PDT) Original-Received: from zimbra.cs.ucla.edu ([127.0.0.1]) by localhost (zimbra.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id 0f6bZb-9-kef; Mon, 29 Oct 2018 00:22:16 -0700 (PDT) Original-Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id 09424160067; Mon, 29 Oct 2018 00:22:16 -0700 (PDT) X-Virus-Scanned: amavisd-new at zimbra.cs.ucla.edu Original-Received: from zimbra.cs.ucla.edu ([127.0.0.1]) by localhost (zimbra.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id xZfcd9tcI7Os; Mon, 29 Oct 2018 00:22:15 -0700 (PDT) Original-Received: from [192.168.1.9] (cpe-23-242-74-103.socal.res.rr.com [23.242.74.103]) by zimbra.cs.ucla.edu (Postfix) with ESMTPSA id D7C5A16005E; Mon, 29 Oct 2018 00:22:15 -0700 (PDT) In-Reply-To: Content-Language: en-US X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 208.118.235.43 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.org@gnu.org Original-Sender: "bug-gnu-emacs" Xref: news.gmane.org gmane.emacs.bugs:151766 Archived-At: Thomas Fitzsimmons wrote: > Paul Eggert writes: > >> Wonderful. Yet another reason we need to get the pdumper branch working. Anyway: >> >> 1. Can you use strace and/or GDB to investigate how ./temacs is >> disabling address randomization? In the emacs-26 branch, if you run >> this command in src: >> >> strace -f -o /tmp/tr ./temacs --batch --load loadup bootstrap >> >> the output file /tmp/tr should contain something like this: >> >> 18406 personality(0xffffffff) = 0 (PER_LINUX) >> 18406 personality(PER_LINUX|ADDR_NO_RANDOMIZE) = 0 (PER_LINUX) >> 18406 personality(0xffffffff) = 0x40000 (PER_LINUX|ADDR_NO_RANDOMIZE) > > I see the above personality calls exactly as you've shown them. > > strace never gets to the next execve; the crash happens before the next > execve is run, see below. > >> 18406 execve("./temacs", ["./temacs", "--batch", "--load", "loadup", >> "bootstrap"], 0xc521b0 /* 80 vars */) = 0 So there are no more system calls after personality(0xffffffff)? That is, the crash happens immediately before any other system calls? What does 'strace' say about the crash? For me, the execve is the first syscall after the 'personality(0xffffffff) = 0x40000'. If you're seeing some other syscall there (or are seeing a crash), please investigate why, presumably with GDB. > When I run the command under gdb, it succeeds, so I had to enable core > dumps to get the backtrace: Core dumps won't help us much I'm afraid. Instead, when debugging ./temacs, please use the GDB command "set disable-randomization off" before issuing the GDB command "run --batch --load loadup bootstrap".