From owner-freebsd-current@freebsd.org Wed Nov 1 10:16:51 2017 Return-Path: Delivered-To: freebsd-current@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 71AF7E55D33 for ; Wed, 1 Nov 2017 10:16:51 +0000 (UTC) (envelope-from hps@selasky.org) Received: from mail.turbocat.net (turbocat.net [88.99.82.50]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 37FA266CD0 for ; Wed, 1 Nov 2017 10:16:50 +0000 (UTC) (envelope-from hps@selasky.org) Received: from hps2016.home.selasky.org (unknown [62.141.128.70]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.turbocat.net (Postfix) with ESMTPSA id C3017260100; Wed, 1 Nov 2017 11:16:47 +0100 (CET) Subject: Re: pcsc-lite hangs up after unplugging an USB card reader To: =?UTF-8?Q?Jairo_Montes_Gonz=c3=a1lez?= , ludovic.rousseau@free.fr, freebsd-current@freebsd.org, "Fernandez-Cueto, Roberto" References: <9b50e911-4a19-8f2c-75e9-17fa1b455edd@selasky.org> <27dc1898-074f-4e4b-849b-4985138eec1b@BW-EX-CASHUB.bally-wulff.de> From: Hans Petter Selasky Message-ID: Date: Wed, 1 Nov 2017 11:14:08 +0100 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:52.0) Gecko/20100101 Thunderbird/52.4.0 MIME-Version: 1.0 In-Reply-To: <27dc1898-074f-4e4b-849b-4985138eec1b@BW-EX-CASHUB.bally-wulff.de> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.23 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, 01 Nov 2017 10:16:51 -0000 On 11/01/17 12:05, Jairo Montes González wrote: > Jairo Montes schrieb am 01.11.2017 11:04 > _____________________________________________________________________ > > The output from "procstat -ak" is attached to this email. > Here are the relevant bits: > 898 100592 pcscd - mi_switch sleepq_switch sleepq_catch_signals sleepq_timedwait_sig _cv_timedwait_sig_sbt seltdwait kern_select sys_select amd64_syscall Xfast_syscall > 898 100699 pcscd - mi_switch sleepq_switch sleepq_catch_signals sleepq_wait_sig _sleep pipe_read dofileread kern_readv sys_read amd64_syscall Xfast_syscall > 898 100700 pcscd - mi_switch sleepq_switch sleepq_catch_signals sleepq_wait_sig _sleep umtxq_sleep do_wait __umtx_op_wait amd64_syscall Xfast_syscall > 898 100702 pcscd - mi_switch sleepq_switch sleepq_catch_signals sleepq_wait_sig _cv_wait_sig seltdwait kern_poll sys_poll amd64_syscall Xfast_syscall BTW: I see no USB processes hanging. It looks like pcscd is stuck: 1) waiting for select to complete (normal) 2) waiting on a mutex operation (might be an indication of deadlock) Try to do: thread 100700 bt I'm not sure how you can extend the backtrace into userspace. Maybe you need to do: gdb -p 898 thread 100700 bt To figure out where this software is stuck. It might look like a missed mutex unlock in some error path inside pcscd. --HPS