From owner-freebsd-current@FreeBSD.ORG Wed Jul 27 16:46:25 2011 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 77E42106566C for ; Wed, 27 Jul 2011 16:46:25 +0000 (UTC) (envelope-from dan@dan.emsphone.com) Received: from email2.allantgroup.com (email2.emsphone.com [199.67.51.116]) by mx1.freebsd.org (Postfix) with ESMTP id 23B5A8FC15 for ; Wed, 27 Jul 2011 16:46:24 +0000 (UTC) Received: from dan.emsphone.com (dan.emsphone.com [199.67.51.101]) by email2.allantgroup.com (8.14.4/8.14.4) with ESMTP id p6RGZoJU024102 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Wed, 27 Jul 2011 11:35:50 -0500 (CDT) (envelope-from dan@dan.emsphone.com) Received: from dan.emsphone.com (smmsp@localhost [127.0.0.1]) by dan.emsphone.com (8.14.5/8.14.5) with ESMTP id p6RGZo9m035530 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Wed, 27 Jul 2011 11:35:50 -0500 (CDT) (envelope-from dan@dan.emsphone.com) Received: (from dan@localhost) by dan.emsphone.com (8.14.5/8.14.5/Submit) id p6RGZnON035529; Wed, 27 Jul 2011 11:35:49 -0500 (CDT) (envelope-from dan) Date: Wed, 27 Jul 2011 11:35:49 -0500 From: Dan Nelson To: Alexander Best Message-ID: <20110727163549.GD6562@dan.emsphone.com> References: <20110727003004.GA61713@freebsd.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110727003004.GA61713@freebsd.org> X-OS: FreeBSD 8.2-STABLE User-Agent: Mutt/1.5.21 (2010-09-15) Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by dan.emsphone.com id p6RGZo9m035530 X-Virus-Scanned: clamav-milter 0.97.2 at email2.allantgroup.com X-Virus-Status: Clean X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.6 (email2.allantgroup.com [199.67.51.78]); Wed, 27 Jul 2011 11:35:50 -0500 (CDT) X-Scanned-By: MIMEDefang 2.68 on 199.67.51.78 Cc: freebsd-current@freebsd.org Subject: Re: truss crashing process X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 27 Jul 2011 16:46:25 -0000 In the last episode (Jul 27), Alexander Best said: > hi there, > > i was trying to attach truss to chromium via > > 'truss -p 18445' and got: > > [...] > kevent(26,{},0,{0x1b,EVFILT_READ,0x0,0,0x1,0x44cb600 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x! 0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,! 0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,0x0,0x0,0,0x0,0x0 0x0,! 0x0,0x0, > -- UNKNOWN SYSCALL -14720592 -- > write(-14720976,0x8080808080808000,0) = 41 (0x29) > select(94,0x6acd,{0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 40 41 42 43 44 45 46 70 71 72 73 76 77 78 79 80 81 82 84 87 88 91},0x1,{0.85048848 }) = 73 (0x49) > -- UNKNOWN SYSCALL 303120384 -- > #94(0x0,0x0,0x5e,0xb6cd600,0x83ed780,0x3dae410) = 189 (0xbd) > truss: Cannot malloc -14740096 bytes for fd_set array: Cannot allocate memory Invalid syscalls numbers like that usually mean that truss has attached to a process in the middle of a syscall. The ptrace API fires the same event for syscall enter and exit, so if truss is expecting an enter and gets an exit, you get a mangled syscall number and eventually truss will coredump trying to decode incorrect data. Try applying the patch at https://www.evoy.net/FreeBSD/truss.diff , which amongst other things, fixes this problem. If you just want the syscall fix, search the diff for "50-50 chance" and manually patch that if(){} block in your source. -- Dan Nelson dnelson@allantgroup.com