From mboxrd@z Thu Jan 1 00:00:00 1970 From: ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org (Eric W. Biederman) Subject: Re: [PATCH v4 0/2] Add further ioctl() operations for namespace discovery Date: Fri, 03 Feb 2017 15:34:04 +1300 Message-ID: <87wpd82ear.fsf@xmission.com> References: <93e5c7f9-9dc1-6c93-ad20-0ba053d8bfef@gmail.com> <963f76f9-3ae5-b316-e688-00d3e59cad30@gmail.com> <87d1fblx2s.fsf@xmission.com> <877f5jlvs1.fsf@xmission.com> <87tw8nkh4k.fsf@xmission.com> <87a8aea1pp.fsf@xmission.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <87a8aea1pp.fsf-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org> (Eric W. Biederman's message of "Thu, 26 Jan 2017 17:23:46 +1300") Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: "Michael Kerrisk (man-pages)" Cc: "Serge E. Hallyn" , Linux API , lkml , "linux-fsdevel@vger.kernel.org" , Andrey Vagin , James Bottomley , "W. Trevor King" , Alexander Viro List-Id: linux-api@vger.kernel.org ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org (Eric W. Biederman) writes: > "Michael Kerrisk (man-pages)" writes: > > >> On 25 January 2017 at 15:28, Eric W. Biederman wrote: > >>> My concern is that the difference between returning -EOVERFLOW and >>> overflow_uid is primarily about usability. If you haven't played with >>> the usability I don't trust that we have made the proper trade off. >> >> So, I had not initially included the no-UID-mapping case, and when you >> proposed -EOVERFLOW for that case, it seemed better. >> >> On reflection, mapping to the overflow_uid seems simpler. Taking the >> example shown in my other mail a short time ago, the unmapped UID 0 >> from the outer namespace would map to the overflow_uid (which UID my >> program would print), but my program would still correctly report that >> the UID 0 process in the outer namespace might (subject to LSM checks) >> have capabilities in the inner namespace. >> >> So, it seems that reverting the EOVERFLOW change is in order (and my >> example program thus needs no changes). Does that sound reasonable to >> you? > > It does. I just care that you have thought through the tradeoffs of > that corner of the interface design. So I have just reverted the EOVERFLOW change, applied the patches to my tree and pushed this to for-next. Otherwise this looks like this effort will have stalled. Eric From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from out02.mta.xmission.com ([166.70.13.232]:48529 "EHLO out02.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751653AbdBCCil (ORCPT ); Thu, 2 Feb 2017 21:38:41 -0500 From: ebiederm@xmission.com (Eric W. Biederman) To: "Michael Kerrisk \(man-pages\)" Cc: "Serge E. Hallyn" , Linux API , lkml , "linux-fsdevel\@vger.kernel.org" , Andrey Vagin , James Bottomley , "W. Trevor King" , Alexander Viro References: <93e5c7f9-9dc1-6c93-ad20-0ba053d8bfef@gmail.com> <963f76f9-3ae5-b316-e688-00d3e59cad30@gmail.com> <87d1fblx2s.fsf@xmission.com> <877f5jlvs1.fsf@xmission.com> <87tw8nkh4k.fsf@xmission.com> <87a8aea1pp.fsf@xmission.com> Date: Fri, 03 Feb 2017 15:34:04 +1300 In-Reply-To: <87a8aea1pp.fsf@xmission.com> (Eric W. Biederman's message of "Thu, 26 Jan 2017 17:23:46 +1300") Message-ID: <87wpd82ear.fsf@xmission.com> MIME-Version: 1.0 Content-Type: text/plain Subject: Re: [PATCH v4 0/2] Add further ioctl() operations for namespace discovery Sender: linux-fsdevel-owner@vger.kernel.org List-ID: ebiederm@xmission.com (Eric W. Biederman) writes: > "Michael Kerrisk (man-pages)" writes: > > >> On 25 January 2017 at 15:28, Eric W. Biederman wrote: > >>> My concern is that the difference between returning -EOVERFLOW and >>> overflow_uid is primarily about usability. If you haven't played with >>> the usability I don't trust that we have made the proper trade off. >> >> So, I had not initially included the no-UID-mapping case, and when you >> proposed -EOVERFLOW for that case, it seemed better. >> >> On reflection, mapping to the overflow_uid seems simpler. Taking the >> example shown in my other mail a short time ago, the unmapped UID 0 >> from the outer namespace would map to the overflow_uid (which UID my >> program would print), but my program would still correctly report that >> the UID 0 process in the outer namespace might (subject to LSM checks) >> have capabilities in the inner namespace. >> >> So, it seems that reverting the EOVERFLOW change is in order (and my >> example program thus needs no changes). Does that sound reasonable to >> you? > > It does. I just care that you have thought through the tradeoffs of > that corner of the interface design. So I have just reverted the EOVERFLOW change, applied the patches to my tree and pushed this to for-next. Otherwise this looks like this effort will have stalled. Eric