From owner-freebsd-questions@freebsd.org Thu Feb 15 09:06:09 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 E0028F0A42F for ; Thu, 15 Feb 2018 09:06:09 +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 744116BAF4 for ; Thu, 15 Feb 2018 09:06:09 +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=1518685567; bh=qu+5y53DGyntZsYOu72U0tQhCpBdsZ4QS+yARFXMTLU=; h=Subject:To:Cc:References:From:Date:In-Reply-To; b=pdcAOLOeaDg3/uVKmvrTw/cmw9W4V3c78pSTTLmngaBWRo97mS0Ct9K5iyI/LIwDy wMBNZHhcMV15rn+V20qCDDX33LI1/w+6sHr6zNiCmu/q1IyYbPHpAotY4OBHaKG6BB KvuTC9gUrlOpnRaJhSCSmSEZv4jKZVUXAvQ+YpXQ= Subject: Re: which limit is hit here? To: Michael Schuster Cc: FreeBSD Mailing List References: From: Per olof Ljungmark Message-ID: <71635f3b-0494-1956-fa31-bd8df7b72a93@nethead.se> Date: Thu, 15 Feb 2018 10:06:02 +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: 7bit 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 09:06:10 -0000 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 ?? ()