From owner-freebsd-hackers@FreeBSD.ORG Wed Oct 5 18:03:28 2011 Return-Path: Delivered-To: hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 8125B1065676 for ; Wed, 5 Oct 2011 18:03:28 +0000 (UTC) (envelope-from artemb@gmail.com) Received: from mail-yw0-f54.google.com (mail-yw0-f54.google.com [209.85.213.54]) by mx1.freebsd.org (Postfix) with ESMTP id 3F4FD8FC14 for ; Wed, 5 Oct 2011 18:03:28 +0000 (UTC) Received: by ywp17 with SMTP id 17so2316274ywp.13 for ; Wed, 05 Oct 2011 11:03:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type :content-transfer-encoding; bh=M9/L5PejkQpal+bqnEhQAb213Ijlr7E3ZTyV6lfNV7c=; b=cEAgKiMfrsjTwor8BzSG9RUydphLyQvLz9L+dsaD8IgQ3Z5Oy01vbNp/cVSzqMuOxM 0MuORVfpS2AVIBREPbM6E1v/KeqfQlXbjcb8844FNiXErfvzYYD6pAinVINRAs1qXRpK s+4woDPa8Iy1mo6oqZFoxYJwXg9Lh2VQV5ECY= MIME-Version: 1.0 Received: by 10.236.186.35 with SMTP id v23mr15532083yhm.80.1317837807265; Wed, 05 Oct 2011 11:03:27 -0700 (PDT) Sender: artemb@gmail.com Received: by 10.236.103.33 with HTTP; Wed, 5 Oct 2011 11:03:27 -0700 (PDT) In-Reply-To: <86fwj84p8i.fsf@ds4.des.no> References: <86sjn84wco.fsf@ds4.des.no> <86obxw4s4w.fsf@ds4.des.no> <86fwj84p8i.fsf@ds4.des.no> Date: Wed, 5 Oct 2011 11:03:27 -0700 X-Google-Sender-Auth: c1GV_fPHohYcJtOdgT0dQX_cbgw Message-ID: From: Artem Belevich To: =?ISO-8859-1?Q?Dag=2DErling_Sm=F8rgrav?= Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Cc: hackers@freebsd.org, =?ISO-8859-1?Q?Trond_Endrest=F8l?= Subject: Re: Does anyone use nscd? X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 05 Oct 2011 18:03:28 -0000 2011/10/4 Dag-Erling Sm=F8rgrav : > Any chance of getting a backtrace from an unpatched nscd? =A0Ideally with > the change described here: > > http://www.freebsd.org/cgi/query-pr.cgi?pr=3Dbin/136073#reply1 > > To test, stop nscd, then run it from the command line like so: > > $ su - > # cd /tmp > # ulimit -c 0 > # /usr/sbin/nscd -nst > (do something in another terminal that causes it to crash) > # echo backtrace | gdb -batch -x /dev/stdin /usr/sbin/nscd nscd.core > > and send me the output from both nscd and gdb once it crashes. In my case it's top that dies with SIGPIPE. nscd keeps running just fine. So, there's no backtrace from nscd. top receives SIGPIPE after it tries to write to the socket with nscd on the other end. Apparently nscd closes connection on its end. Running ktrace on top I see that before the write to nscd socket, there's a read that returned 0 bytes. Here's top's backtrace. Alas I don't have libc with debug symbols handy: Program received signal SIGPIPE, Broken pipe. 0x0000000800abe8cc in write () from /lib/libc.so.7 (gdb) where #0 0x0000000800abe8cc in write () from /lib/libc.so.7 #1 0x0000000800aa3f44 in ftell () from /lib/libc.so.7 #2 0x0000000800aa415f in ftell () from /lib/libc.so.7 #3 0x0000000800aa2031 in __h_errno () from /lib/libc.so.7 #4 0x0000000800a98311 in nsdispatch () from /lib/libc.so.7 #5 0x0000000800a84d95 in getpwent_r () from /lib/libc.so.7 #6 0x0000000800a84911 in acl_get_brand_np () from /lib/libc.so.7 #7 0x0000000000404f7b in machine_init (statics=3D0x7fffffffe770, do_unames=3D1 '\001') at /usr/srcdir/src.git/usr.bin/top/machine.c:258 #8 0x000000000040a9ab in main (argc=3D1, argv=3D0x7fffffffe8c8) at /usr/srcdir/src.git/usr.bin/top/../../contrib/top/top.c:464 --Artem