From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964893AbbBISSa (ORCPT ); Mon, 9 Feb 2015 13:18:30 -0500 Received: from mail-wi0-f175.google.com ([209.85.212.175]:60071 "EHLO mail-wi0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933233AbbBISS3 (ORCPT ); Mon, 9 Feb 2015 13:18:29 -0500 Message-ID: <54D8F9F1.4000300@gmail.com> Date: Mon, 09 Feb 2015 19:18:25 +0100 From: Piotr Karbowski User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: Piotr Karbowski , Al Viro CC: linux-kernel@vger.kernel.org Subject: [BUMP] [BUG] rename() from outside of the target dir breaks /proc exe symlink. References: <549EEEEA.1050306@gmail.com> <20141227181412.GG22149@ZenIV.linux.org.uk> <54A329C1.9030704@gmail.com> <54B957B5.8000202@gmail.com> In-Reply-To: <54B957B5.8000202@gmail.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/16/2015 07:25 PM, Piotr Karbowski wrote: > On 12/30/2014 11:40 PM, Piotr Karbowski wrote: >> Hi Al, >> >> On 12/27/2014 07:14 PM, Al Viro wrote: >>> That's because it never _had_ worked. Note that opening the damn thing >>> will give the right file - it does not work by traversing the result of >>> readlink(2). readlink(2) output on those is not promised to be useful >>> in all cases; often enough it is, but it won't work on cross-directory >>> renames, it can't be used to tell a filename that really ends with " >>> (deleted)" >>> from a removed file, etc. Moreover, it only very recently became >>> usable for >>> victim names with the last component longer than 40 characters if you >>> did an >>> overwriting rename. >>> >>> What are you trying to use it for? >> >> I am using it to track the origin of running processes. I am working >> with continuous integration of a Linux embedded software. The tests goes >> in Linux containers, multiple instances of binary with the same name in >> a single container/namespace, all with cwd symlink pointing to / which >> looks from outside virtually the same, the binaries are modified at >> runtime by coping, modifing and replacing for another execution of the >> same binary (using patchelf to add additional NEEDED to header or change >> rpath or dynamic loader and such). >> >> In my very usecase, the exe symlink is essential. > > *Friendly bump* > > Can anything be done about it or is there any other mechanism that I > could use to get origin of the running binary? *Even friendlier bump* -- Piotr.