From owner-freebsd-questions@freebsd.org Thu Feb 15 09:54:50 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 6F732F0DF8D for ; Thu, 15 Feb 2018 09:54:50 +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 0B4306E465 for ; Thu, 15 Feb 2018 09:54:49 +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=1518688488; bh=w3cjpnXAh4fLP18oa+jndBGU03C/2L7G5BZ+8hobl2o=; h=Subject:To:Cc:References:From:Date:In-Reply-To; b=5CBpzFZkJgITAuWQpcnPrBgK6Irbtnd6kzEee0ogBWyD1Sey9wxXlpsEuVv0k14rP ZpBbWeHPGYMi4taZ0btuWGD+atmmkoRXc0cvqI8rc00e2DOv4aMCinAyRmS8Ra5vyT q7lCdbFsMZWa8KMnG7FBQ1i0jN0ZTfE0uCGeZy/E= 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: <0d45799f-cd71-86e2-9c70-d8da3b64364d@nethead.se> Date: Thu, 15 Feb 2018 10:54:46 +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 09:54:50 -0000 On 02/15/18 10:31, Michael Schuster wrote: > > > On Thu, Feb 15, 2018 at 10:27 AM, Per olof Ljungmark > wrote: > > > > 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." > > > is that really all? Yes, that is what is says. >  I'd expect something like this (library names removed by me) - this is > not on BSD, btw, but I'd expect gdb to behave in a similar fashion: > > (gdb) info shared > From        To          Syms Read   Shared Object Library > 0x01120000  0x011b090c  Yes         xxxx > 0x78a3e000  0x78a64660  Yes (*)     xxxxxx > 0x78317000  0x7831d290  Yes (*)     xxxxxx.so > 0x78087000  0x78087000  No          xxxxxxxxxxxx.so.1.1 > 0x78056000  0x78056000  No          xxxxxxxxxx.1.2 > 0x7801f000  0x7801f000  No          xxxxxxxxxxxxso.1.0 > 0x7800c000  0x7800c000  No          xxxxxxxxxx.so.1.0 > 0x78000000  0x78000000  No          xxxxxxxxxxxxxx.so.1.0 > 0x78017000  0x78017000  No          xxxxxxxxx.so.1.0 > 0x78129000  0x7819f960  Yes         xxxxxxso > 0x78037000  0x78040768  Yes         xxxxxxxx.so > 0x78025000  0x7802f6e0  Yes         xxxxxxxxso.2 > 0x78047000  0x78054970  Yes         xxxxxxxxxxx.so > (*): Shared library is missing debugging information. > (gdb) > >   > > > > > > 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 > > > > > -- > 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