From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dennis Kaarsemaker Subject: Segfault in git reflog Date: Wed, 30 Dec 2015 10:24:01 +0100 Message-ID: <20151230092400.GA9319@spirit> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii To: git@vger.kernel.org X-From: git-owner@vger.kernel.org Wed Dec 30 10:24:42 2015 Return-path: Envelope-to: gcvg-git-2@plane.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1aECzm-0004ty-Dw for gcvg-git-2@plane.gmane.org; Wed, 30 Dec 2015 10:24:38 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752857AbbL3JYK (ORCPT ); Wed, 30 Dec 2015 04:24:10 -0500 Received: from mail-wm0-f43.google.com ([74.125.82.43]:34982 "EHLO mail-wm0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751795AbbL3JYG (ORCPT ); Wed, 30 Dec 2015 04:24:06 -0500 Received: by mail-wm0-f43.google.com with SMTP id f206so31840983wmf.0 for ; Wed, 30 Dec 2015 01:24:04 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kaarsemaker-net.20150623.gappssmtp.com; s=20150623; h=date:from:to:subject:message-id:mime-version:content-type :content-disposition:user-agent; bh=xsxvAXLy95Ru5RVDZdTqr25zo02rW6tNfKfYUv3g06A=; b=OaHIVzZaqsm/ELsccCPYUBODtH0u+6bTfVN+TQzDvjV/ziaF0VTh3P6OAZr1twUe8/ GNs7TQP3wKdfXrweZ+Yc4tb1N7mMHvt0zjiZfOmdt0OJQL/DD/A0JK2JYoVXTLf3rJXZ pKs+ZaHJM8plV8HkrUQkrNaLSj4PlH7yCjnChFaDzHAIu880VhrF84z7dyLFnHc3gXW+ YqkbSEa/Pycgc85UlLhc2BdrxReks+734NBZNGbK77vraN/vZPnB3djwW5MsL0h4K1g9 2kNzLyqeqnSUOzD0CiOQyLLWR0xj/BG9A83HdWb1+u/+S9H6T5rCr9BBPvcScmWNCjr4 TQTw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:date:from:to:subject:message-id:mime-version :content-type:content-disposition:user-agent; bh=xsxvAXLy95Ru5RVDZdTqr25zo02rW6tNfKfYUv3g06A=; b=bhuf3zCnelGf2rLFpFozR/vcVwomN3Mtkrxn1LfTnlatPKVJJw6Vmg3dHC7MjxuJTw n+li1DqkWA64TwXd37/t4lhH4B0Z3nLyNyFmTYT404CU3rQfBWjrCMtGY49tH612DH1R i+43+LCox62WPkSwwAhZjXSFzFqPKrflnOORJ6H/+tz2TGRCsQGJhBs5vyuCjx2b70YK phuGYkiriKIxAoCxoLaR1u/Np16CEPafPab96CyoO9AgaisO0S8NGWqUbX08pr09EFEa PD3oU1UdedxEd5Ou1Y7Pm3w4FZ7BLBkfUtzLNp8gjBpvURH8WR2AbWgggj3LmwSdfx3C i02Q== X-Gm-Message-State: ALoCoQkFeOnPt4m2/z9/oL7jQquzYHiVADz1MnQmj/LnCmge+2hn0EnniKkrMiJn/tiZwNGiH47vC++yPCLMaMH0Ox+LiLi48Q== X-Received: by 10.194.123.8 with SMTP id lw8mr68638108wjb.72.1451467444238; Wed, 30 Dec 2015 01:24:04 -0800 (PST) Received: from spirit ([145.132.209.114]) by smtp.gmail.com with ESMTPSA id m65sm33016884wma.13.2015.12.30.01.24.03 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 30 Dec 2015 01:24:03 -0800 (PST) Content-Disposition: inline User-Agent: Mutt/1.5.23 (2014-03-12) Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: I've hit a segfault in git reflog with latest git, reproducable in git.git: spirit:~/code/git (master)$ ./git describe v2.7.0-rc3 I've minimized the reflog to: spirit:~/code/git (master)$ cat .git/logs/HEAD 2635c2b8bfc9aec07b7f023d8e3b3d02df715344 54bc41416c5d3ecb978acb0df80d57aa3e54494c Dennis Kaarsemaker 1446765642 +0100 74c855f87d25a5b5c12d0485ec77c785a1c734c5 54bc41416c5d3ecb978acb0df80d57aa3e54494c Dennis Kaarsemaker 1446765951 +0100 checkout: moving from 3c3d3f629a6176b401ebec455c5dd59ed1b5f910 to master ...which I realize looks a bit broken. I think at the time I was playing with some patches that also caused segfaults, causing gaps in the reflog. Nevertheless, I think segfaulting is bad. All objects in the reflog are reachable. gdb has the following to say: spirit:~/code/git (master)$ gdb --args ./git --no-pager reflog (gdb) run Starting program: /home/dennis/code/git/git --no-pager reflog [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1". 28274d0 (HEAD -> master, tag: v2.7.0-rc3, upstream/master, peff/jk/tag-source-propagate, peff/jk/sigpipe-report, gitster/master) HEAD@{0}: checkout: moving from 3c3d3f629a6176b401ebec455c5dd59ed1b5f910 to master Program received signal SIGSEGV, Segmentation fault. copy_commit_list (list=0x4834dc7000000011) at commit.c:450 450 pp = commit_list_append(list->item, pp); (gdb) bt #0 copy_commit_list (list=0x4834dc7000000011) at commit.c:450 #1 0x000000000050705e in save_parents (commit=commit@entry=0x928a90, revs=0x7fffffffcb80) at revision.c:3044 #2 0x000000000050a54e in get_revision_1 (revs=revs@entry=0x7fffffffcb80) at revision.c:3119 #3 0x000000000050a710 in get_revision_1 (revs=) at revision.c:3112 #4 get_revision_internal (revs=0x7fffffffcb80) at revision.c:3248 #5 0x000000000050a99d in get_revision (revs=revs@entry=0x7fffffffcb80) at revision.c:3322 #6 0x0000000000446032 in cmd_log_walk (rev=rev@entry=0x7fffffffcb80) at builtin/log.c:344 #7 0x0000000000446bf8 in cmd_log_reflog (argc=1, argv=0x7fffffffd6a8, prefix=0x0) at builtin/log.c:626 #8 0x0000000000406126 in run_builtin (argv=0x7fffffffd6a8, argc=1, p=0x7bbec0 ) at git.c:350 #9 handle_builtin (argc=1, argv=0x7fffffffd6a8) at git.c:536 #10 0x0000000000405261 in run_argv (argv=0x7fffffffd4c8, argcp=0x7fffffffd4ac) at git.c:582 #11 main (argc=1, av=) at git.c:690 (gdb) p list $1 = (struct commit_list *) 0x4834dc7000000011 (gdb) p list->item Cannot access memory at address 0x4834dc7000000011 A bisect blames 53d00b3 (log: use true parents for diff even when rewriting), which does indeed touch the code that seems to be segfaulting. I've tried digging into this, but didn't get very far. -- Dennis Kaarsemaker