From owner-freebsd-questions@freebsd.org Thu Feb 15 09:27:28 2018 Return-Path: Delivered-To: freebsd-questions@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 87F31F0BE77 for ; Thu, 15 Feb 2018 09:27:28 +0000 (UTC) (envelope-from peo@nethead.se) Received: from ns1.nethead.se (ns1.nethead.se [5.150.237.139]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "ns1.nethead.se", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id ED2BE6CFB8 for ; Thu, 15 Feb 2018 09:27:27 +0000 (UTC) (envelope-from peo@nethead.se) X-Virus-Scanned: amavisd-new at Nethead AB DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=nethead.se; s=NETHEADSE; t=1518686846; bh=l8c56ebOwmWNlm/DUgZ0UbvmxDojoZdMg512UVdiSWM=; h=Subject:To:Cc:References:From:Date:In-Reply-To; b=YRhP1gTDD6XtUod0QlowIc6bRzkaxpj10N3iwVRpKV7UBzWAawGY+PnqV3UowrvKS VmtxNkE7+6AGb0sEvIJxlSTK901StCccuJRCEgt9RCGu0ubTW6JHTpetODen33g9+3 T8FXov8cG6Ogdv/w4YK9puGEjTnuhjjwh4twrR78= Subject: Re: which limit is hit here? To: Michael Schuster Cc: FreeBSD Mailing List References: <71635f3b-0494-1956-fa31-bd8df7b72a93@nethead.se> From: Per olof Ljungmark Message-ID: Date: Thu, 15 Feb 2018 10:27:23 +0100 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 15 Feb 2018 09:27:28 -0000 On 02/15/18 10:07, Michael Schuster wrote: > hmm ...  > > what does gdb's "info shared" print out? "No shared libraries loaded at this time." > > On Thu, Feb 15, 2018 at 10:06 AM, Per olof Ljungmark > wrote: > > On 02/15/18 08:56, Michael Schuster wrote: > > Hi Per, > > > > On Thu, Feb 15, 2018 at 8:41 AM, Per olof Ljungmark > > >> wrote: > > > >     Hi, > > > >     A process "squatter" from Cyrus-IMAP version 2.5.11 exits with signal > >     11. The purpose of the process is to create an index of the content in a > >     mailbox. > > > >     On large mailboxes, squatter coredumps, the final message from truss > >     reads: > > > >     mmap(0x0,700448768,PROT_READ|PROT_WRITE,MAP_PRIVATE|MAP_ANON,-1,0x0) = > >     34783363072 (0x819400000) > >     mmap(0x0,936334732,PROT_READ,MAP_SHARED,107,0x0) = 35483811840 > >     (0x843000000) > >     SIGNAL 11 (SIGSEGV) > >     process killed, signal = 11 (core dumped) > > > > > > to me this looks like the error is happening *after* mmap() returned > > successfully - most likely because "someone" miscalculates some pointer > > and tries to access an unmapped address. Maybe (but that's conjecture), > > PROT_READ is wrong here and someone is attempting to write to that > > mapped region; I'm not 100% sure though whether that'd actually trigger > > SIGSEGV. > > > > I'd suggest you do something like > > $ gdb squatter core > > (gdb) bt > > > > and look at the output, and maybe go to the maintainers of Cyrus-IMAP... > > Hi, > > gdb says, > > (gdb) bt > #0  0x00000000004049cc in ?? () > #1  0x0000000803456da4 in ?? () > #2  0x0000000804445130 in ?? () > #3  0x003875e5ffffcb00 in ?? () > #4  0x00000008047e7008 in ?? () > #5  0x00000008047e7048 in ?? () > #6  0x00000001040000c0 in ?? () > #7  0x0000000810800000 in ?? () > #8  0x0000000200000045 in ?? () > #9  0x000000083a400000 in ?? () > #10 0x00000008047e8e98 in ?? () > #11 0x00000000000003bb in ?? () > #12 0x00000008047e8eb8 in ?? () > #13 0x00000000000000bf in ?? () > #14 0x0ffd2a151071e550 in ?? () > #15 0x000000bf00000002 in ?? () > #16 0x37cf558c1298d1e7 in ?? () > #17 0x0135682800000000 in ?? () > #18 0x02e00a0e020d0336 in ?? () > #19 0x0487888c03b90d10 in ?? () > #20 0x062618da0556e126 in ?? () > #21 0x0000000006f31067 in ?? () > #22 0x0000000000000000 in ?? () > > > > > -- > Michael Schuster > http://recursiveramblings.wordpress.com/ > recursion, n: see 'recursion' -- Per olof Ljungmark +46 707 50 20 46 Nethead AB Registered in Stockholm, Sweden SE556815226701