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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 D27C3C282DA for ; Wed, 17 Apr 2019 14:23:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A6BAC20872 for ; Wed, 17 Apr 2019 14:23:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732523AbfDQOXG (ORCPT ); Wed, 17 Apr 2019 10:23:06 -0400 Received: from mx1.redhat.com ([209.132.183.28]:56318 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729940AbfDQOXF (ORCPT ); Wed, 17 Apr 2019 10:23:05 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 6D8633008CC7; Wed, 17 Apr 2019 14:22:58 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.43.17.38]) by smtp.corp.redhat.com (Postfix) with SMTP id 1C64E60C66; Wed, 17 Apr 2019 14:22:54 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Wed, 17 Apr 2019 16:22:58 +0200 (CEST) Date: Wed, 17 Apr 2019 16:22:54 +0200 From: Oleg Nesterov To: Christian Brauner Cc: torvalds@linux-foundation.org, viro@zeniv.linux.org.uk, jannh@google.com, dhowells@redhat.com, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org, serge@hallyn.com, luto@kernel.org, arnd@arndb.de, ebiederm@xmission.com, keescook@chromium.org, tglx@linutronix.de, mtk.manpages@gmail.com, akpm@linux-foundation.org, cyphar@cyphar.com, joel@joelfernandes.org, dancol@google.com Subject: Re: [PATCH v1 2/4] clone: add CLONE_PIDFD Message-ID: <20190417142253.GH32622@redhat.com> References: <20190416170233.10208-1-christian@brauner.io> <20190416170233.10208-3-christian@brauner.io> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190416170233.10208-3-christian@brauner.io> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.48]); Wed, 17 Apr 2019 14:23:05 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/16, Christian Brauner wrote: > > + if (clone_flags & CLONE_PIDFD) { > + retval = pidfd_create(pid, &pidfdf); > + if (retval < 0) > + goto bad_fork_free_pid; > + pidfd = retval; > + } ... > + if (clone_flags & CLONE_PIDFD) { > + fd_install(pidfd, pidfdf); > + put_user(pidfd, parent_tidptr); put_user() can fail, I don't think this error should be silently ignored, this can lead to the hard-to-trigger/debug problems. Why can't we do put_user-with-check along with pidfd_create() above? Oleg.