From owner-freebsd-stable@freebsd.org Thu Apr 26 16:05:55 2018 Return-Path: Delivered-To: freebsd-stable@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 379BEFB1940 for ; Thu, 26 Apr 2018 16:05:55 +0000 (UTC) (envelope-from freebsd-stable-local@be-well.ilk.org) Received: from be-well.ilk.org (be-well.ilk.org [23.30.133.173]) by mx1.freebsd.org (Postfix) with ESMTP id CE0A385F67; Thu, 26 Apr 2018 16:05:54 +0000 (UTC) (envelope-from freebsd-stable-local@be-well.ilk.org) Received: by be-well.ilk.org (Postfix, from userid 1147) id 79DE033C22; Thu, 26 Apr 2018 12:05:53 -0400 (EDT) From: Lowell Gilbert To: Dimitry Andric Cc: FreeBSD Stable Subject: Re: gptboot broken when compiled with clang 6 and WITHOUT_LOADER_GELI -- clang 5 is OK References: <20180425165840.GA1330@bali> <3A857D03-607A-4983-A4C2-D3A93119297A@FreeBSD.org> <55C3B174-0A2B-4954-BEB8-BF6688EBB02D@FreeBSD.org> Date: Thu, 26 Apr 2018 12:05:53 -0400 In-Reply-To: <55C3B174-0A2B-4954-BEB8-BF6688EBB02D@FreeBSD.org> (Dimitry Andric's message of "Thu, 26 Apr 2018 13:45:51 +0200") Message-ID: <44tvry9cm6.fsf@be-well.ilk.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.3 (berkeley-unix) MIME-Version: 1.0 Content-Type: text/plain X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 26 Apr 2018 16:05:55 -0000 Dimitry Andric writes: > On 26 Apr 2018, at 12:06, Dimitry Andric wrote: >> >> On 26 Apr 2018, at 06:17, Dewayne Geraghty wrote: >>> >>> Andre, You're not alone. I think there's a problem with clang6 on i386 >>> FreeBSD 11.1X, refer: >>> https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=227552 >>> https://forums.freebsd.org/threads/uptime-w-i386-breakage.65584/ >>> and perhaps also on amd64, search for >>> https://bugs.freebsd.org/bugzilla/buglist.cgi?quicksearch=clang&list_id=226390. >>> >>> Without time to investigate I've reverted userland >>> FreeBSD 11.2-PRERELEASE r332843M amd64 1101515 1101509 >>> FreeBSD 11.2-PRERELEASE r332843M i386 1101515 1101509 >> >> As noted in another post, I cannot reproduce the problems with gptboot, >> but with FreeBSD-11.2-PRERELEASE-i386-20180420-r332802, I do indeed see >> w and uptime crashing in libxo: >> >> (gdb) bt >> #0 ifree (tsd=0x28000000) at arena.h:799 >> #1 0x2814b506 in __free (ptr=0x280601ef) at tsd.h:716 >> #2 0x2808bb07 in xo_do_emit_fields () at /usr/src/contrib/libxo/libxo/libxo.c:6419 >> #3 0x28089a1c in xo_do_emit (xop=, flags=> optimized out>, fmt=0x804ad4d "{:time-of-day/%s} ") at >> /usr/src/contrib/libxo/libxo/libxo.c:6470 >> #4 0x28089b61 in xo_emit (fmt=0x804ad4d "{:time-of-day/%s} ") at /usr/src/contrib/libxo/libxo/libxo.c:6541 >> #5 0x08049f50 in main (argc=, argv=) at /usr/src/usr.bin/w/w.c:475 >> #6 0x080494cd in _start1 () >> #7 0x08049448 in _start () >> #8 0x00000000 in ?? () >> >> Not sure if this has anything to do with clang though, it looks more >> like a double free to me, at first glance. I'll do some debugging. > > Strangely, simply recompiling libxo fixes the problem, or at least works > around it. This is on the r332802 snapshot, so I guess the libxo.so.0 > file shipped may be broken, somehow. Actually, that is a recurring bug (https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=227552) and does seem to be some kind of initialization problem with clang.