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=-3.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, USER_AGENT_NEOMUTT 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 6A103C43381 for ; Tue, 26 Mar 2019 16:23:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2335D2063F for ; Tue, 26 Mar 2019 16:23:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=brauner.io header.i=@brauner.io header.b="aS3IM9hR" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731769AbfCZQXo (ORCPT ); Tue, 26 Mar 2019 12:23:44 -0400 Received: from mail-ed1-f66.google.com ([209.85.208.66]:37419 "EHLO mail-ed1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730458AbfCZQXn (ORCPT ); Tue, 26 Mar 2019 12:23:43 -0400 Received: by mail-ed1-f66.google.com with SMTP id v21so11317382edq.4 for ; Tue, 26 Mar 2019 09:23:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=brauner.io; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=/f3zwl1dB21rcdrfBXeBdunL5xhvMrWPAPDl495IyQI=; b=aS3IM9hR6/PivI8WcUGrqV+2AXvtLDzfx26v9VvUAaQh7z+g3/0Ju9bxwRW+Mjq/n9 Owc1vnVFhgYD30vvS2cioyn/sx8pbNVHlxHCdl7oYG2Ffiayd/sqy0BztTY4M+WZvtxD LC7y7VygFw6K5930Mvm0lS071O4LwuB8UlguZ6EmTV5GUJUvI8k7ifJALza/jMSIfILO k62O1jXuNxVXcej2yyWc2pFDxpSRIoKSi1KERZXUV97DRRveQlNBpYvz8/sEpVBQDPGm 99PL63xOfIN2jmCa4KwBrMSqCRTpnUKuNWzwM1NR5sceSRJkDX2nufo/D5yXZeTjJKAR ELVg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=/f3zwl1dB21rcdrfBXeBdunL5xhvMrWPAPDl495IyQI=; b=lvIhKZb9SkczK1zdAD/jl9bg25HorvGv+eNOa3VqNZl/ioQkYxpJemHIca1ydBz60M Nxi51k8lqw+eGie+6oRIUU15EZRsIP0ZORDfAnVAgP5JCpm9AKli/zBxKX1mdZ6Cxr9G kQa5QTvSQLT8K6vpR9pyvQqcAzhJh4oQjuw9gR12LDna90cxYcMpztkHZbT8udZuxwDx 9TPE5QTi4fF3jcHIjK1UodnaT7KJqEE88/vFrCxqiX12Z5tBS7BqSUWqCIaMlMo16sX3 mOTmHudy2i7Vs4WI+SKpRPSIpj51KKN7b60maUSngc8JPlkYf3KQSn6Ucm2RquB99G6r VrkQ== X-Gm-Message-State: APjAAAW8d4yoKk7FtU4V5Mamu1/A6gyJuV9atB2Vwu/a5uSjKAeJlHf3 p7Lwtbn7TNfSrg3XEDIAtwfa3Q== X-Google-Smtp-Source: APXvYqyx3aTz7HpdPQOwOKdUfPPNiOcJaZOncwK1h1SCRKNH+V5LFVAVvVbWz7/wOKBasFQQr5Kcww== X-Received: by 2002:a50:ec86:: with SMTP id e6mr2820130edr.204.1553617422089; Tue, 26 Mar 2019 09:23:42 -0700 (PDT) Received: from brauner.io (x59cc895e.dyn.telefonica.de. [89.204.137.94]) by smtp.gmail.com with ESMTPSA id t52sm1607446edd.54.2019.03.26.09.23.39 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Tue, 26 Mar 2019 09:23:41 -0700 (PDT) Date: Tue, 26 Mar 2019 17:23:38 +0100 From: Christian Brauner To: Daniel Colascione Cc: Jann Horn , Konstantin Khlebnikov , Andy Lutomirski , David Howells , "Serge E. Hallyn" , "Eric W. Biederman" , Linux API , linux-kernel , Arnd Bergmann , Kees Cook , Alexey Dobriyan , Thomas Gleixner , Michael Kerrisk-manpages , Jonathan Kowalski , "Dmitry V. Levin" , Andrew Morton , Oleg Nesterov , Nagarathnam Muthusamy , Aleksa Sarai , Al Viro , Joel Fernandes Subject: Re: [PATCH v1 2/4] pid: add pidctl() Message-ID: <20190326162337.o256x7hiodu2qfyg@brauner.io> References: <20190326155513.26964-1-christian@brauner.io> <20190326155513.26964-3-christian@brauner.io> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20180716 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Mar 26, 2019 at 09:17:07AM -0700, Daniel Colascione wrote: > Thanks for the patch. > > On Tue, Mar 26, 2019 at 8:55 AM Christian Brauner wrote: > > > > The pidctl() syscalls builds on, extends, and improves translate_pid() [4]. > > I quote Konstantins original patchset first that has already been acked and > > picked up by Eric before and whose functionality is preserved in this > > syscall: > > We still haven't had a much-needed conversation about splitting this > system call into smaller logical operations. It's important that we > address this point before this patch is merged and becomes permanent > kernel ABI. I don't particularly mind splitting this into an additional syscall like e.g. pidfd_open() but then we have - and yes, I know you'll say syscalls are cheap - translate_pid(), and pidfd_open(). What I like about this rn is that it connects both apis in a single syscall and allows pidfd retrieval across pid namespaces. So I guess we'll see what other people think.