From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:60028 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727704AbeLFNoq (ORCPT ); Thu, 6 Dec 2018 08:44:46 -0500 From: Florian Weimer To: ebiederm@xmission.com (Eric W. Biederman) Cc: =?utf-8?Q?J=C3=BCrg?= Billeter , Christian Brauner , linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, luto@kernel.org, arnd@arndb.de, serge@hallyn.com, jannh@google.com, akpm@linux-foundation.org, oleg@redhat.com, cyphar@cyphar.com, viro@zeniv.linux.org.uk, linux-fsdevel@vger.kernel.org, dancol@google.com, timmurray@google.com, linux-man@vger.kernel.org, keescook@chromium.org, tglx@linutronix.de, x86@kernel.org Subject: Re: [PATCH v4] signal: add taskfd_send_signal() syscall References: <20181206121858.12215-1-christian@brauner.io> <87h8fq7s84.fsf@oldenburg2.str.redhat.com> <87pnue6bp2.fsf@oldenburg2.str.redhat.com> <87efaun587.fsf@xmission.com> Date: Thu, 06 Dec 2018 14:44:36 +0100 In-Reply-To: <87efaun587.fsf@xmission.com> (Eric W. Biederman's message of "Thu, 06 Dec 2018 07:40:24 -0600") Message-ID: <877egm6a7v.fsf@oldenburg2.str.redhat.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-fsdevel-owner@vger.kernel.org List-ID: * Eric W. Biederman: > Floriam are you seeing a problem with this behavior or the way Christian > was describing it? My hope is that you could use taskfd_send_signal one day to send a signal to a process which you *known* (based on how you've written your application) should be running and not in a zombie state, and get back an error if it has exited. If you get this error, only then you wait on the process, using the file descriptor you have, and run some recovery code. Wouldn't that be a reasonable approach once we've got task descriptors? Thanks, Florian