From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 296E0C04EB8 for ; Thu, 6 Dec 2018 18:56:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F1E6420868 for ; Thu, 6 Dec 2018 18:56:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F1E6420868 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726034AbeLFS4y convert rfc822-to-8bit (ORCPT ); Thu, 6 Dec 2018 13:56:54 -0500 Received: from mx1.redhat.com ([209.132.183.28]:46616 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725901AbeLFS4y (ORCPT ); Thu, 6 Dec 2018 13:56:54 -0500 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 9E59D31500AE; Thu, 6 Dec 2018 18:56:53 +0000 (UTC) Received: from oldenburg2.str.redhat.com (ovpn-116-106.ams2.redhat.com [10.36.116.106]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 4807E19C7F; Thu, 6 Dec 2018 18:56:46 +0000 (UTC) From: Florian Weimer To: Andy Lutomirski Cc: Christian Brauner , "Eric W. Biederman" , LKML , "Serge E. Hallyn" , Jann Horn , Andrew Morton , Oleg Nesterov , Aleksa Sarai , Al Viro , Linux FS Devel , Linux API , Daniel Colascione , Tim Murray , linux-man , Kees Cook Subject: Re: [PATCH v2] signal: add procfd_signal() syscall References: <20181120105124.14733-1-christian@brauner.io> <87in0g5aqo.fsf@oldenburg.str.redhat.com> <746B7C49-CC7B-4040-A7EF-82491796D360@brauner.io> <20181202100304.labt63mzrlr5utdl@brauner.io> <8736rebl9s.fsf@oldenburg.str.redhat.com> <20181203180224.fkvw4kajtbvru2ku@brauner.io> <874lbtjvtd.fsf@oldenburg2.str.redhat.com> Date: Thu, 06 Dec 2018 19:56:44 +0100 In-Reply-To: (Andy Lutomirski's message of "Thu, 6 Dec 2018 10:54:02 -0800") Message-ID: <87y392h4b7.fsf@oldenburg2.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.41]); Thu, 06 Dec 2018 18:56:54 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Andy Lutomirski: >> I suppose that's fine. Or alternatively, when thread group support is >> added, introduce a flag that applications have to use to enable it, so >> that they can probe for support by checking support for the flag. >> >> I wouldn't be opposed to a new system call like this either: >> >> int procfd_open (pid_t thread_group, pid_t thread_id, unsigned flags); >> >> But I think this is frowned upon on the kernel side. > > I have no problem with it, except that I think it shouldn’t return an > fd that can be used for proc filesystem access. Oh no, my intention was that it would just be used with *_send_signal and related functions. Thanks, Florian