From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: util-linux-owner@vger.kernel.org Received: from mail-oi0-f42.google.com ([209.85.218.42]:34503 "EHLO mail-oi0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756641AbcJMTOK (ORCPT ); Thu, 13 Oct 2016 15:14:10 -0400 Received: by mail-oi0-f42.google.com with SMTP id t73so110732762oie.1 for ; Thu, 13 Oct 2016 12:14:09 -0700 (PDT) Subject: Re: more(1) may attempt to tcsetattr(3) despite lacking controlling terminal To: Jan Schaumann , util-linux-ng@vger.kernel.org References: <20161013143932.GA29451@netmeister.org> From: Bruce Dubbs Message-ID: <57FFDCFA.4070407@gmail.com> Date: Thu, 13 Oct 2016 14:14:02 -0500 MIME-Version: 1.0 In-Reply-To: <20161013143932.GA29451@netmeister.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Sender: util-linux-owner@vger.kernel.org List-ID: Jan Schaumann wrote: > Hello, > > Yesterday I reported the following bug to the Debian maintainers of the > 'util-linux' package. They suggested I should bring it up here: > > > more(1) may attempt to call tsetattr(3) on stderr even if its process is > not in a process group with a controlling terminal. As a result, > SIGTTOU will be generated, suspending the process. > > The following example illustrates the issue: > > $ /bin/sh -c "timeout 60 /bin/sh -c \"ls | more\"" > > This command will now hang until the timeout, since the shell, ls(1) and > more(1) commands invoked by timeout(1) will be suspended. It does not hang for me, but then I don't use systemd. Perhaps systemd should be fixed. -- Bruce