Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752087AbaLQKpY (ORCPT ); Wed, 17 Dec 2014 05:45:24 -0500 Received: from mail-wg0-f41.google.com ([74.125.82.41]:45807 "EHLO mail-wg0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751206AbaLQKpX (ORCPT ); Wed, 17 Dec 2014 05:45:23 -0500 Date: Wed, 17 Dec 2014 11:45:16 +0100 From: Djalal Harouni To: "Marcel J.E. Mol" Cc: akpm@linux-foundation.org, adobriyan@gmail.com, ebiederm@xmission.com, oleg@redhat.com, luto@amacapital.net, linux-kernel@vger.kernel.org Subject: Re: [PATCH] Make /proc//io world readable Message-ID: <20141217104516.GA3202@dztty> References: <20141211162228.GA10717@rim.emol.mesa.nl> <20141211192911.GA3080@dztty> <20141211230453.GB30907@joshua.mesa.nl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20141211230453.GB30907@joshua.mesa.nl> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Marcel (sorry for my late response), On Fri, Dec 12, 2014 at 12:04:53AM +0100, Marcel J.E. Mol wrote: > On Thu, Dec 11, 2014 at 08:29:11PM +0100, Djalal Harouni wrote: > > Hi, > > > > On Thu, Dec 11, 2014 at 05:22:28PM +0100, Marcel Mol wrote: > > > /proc//io is only readable by the pid owner, while files > > > like stat, statm and status are world readable. > > > I see no reason why io statistics should be hidden. > > > This patch makes io also world readable so process io counts > > > can be analysed without root permissions. > > As Andy noted this should be the other way around! so unless you have > > a real usecase, this will revert previous patch by Vasiliy that closed > > some info leaks... > > https://lkml.org/lkml/2011/7/27/459 > > > > Thanks! > > Hi Djalal, thanks for pointing this out. I did look for info like this, > but did not look that far back. I can see the issues Vasiliy points out. > > I do not have a real important usecase, but it is just convenience. > On my home (personal) workstation I trust noone is looking for my > password length in ssh or ftp, but I sometimes do like to see what > process is keeping my disk busy. And I want to limit switching to > root... Even if capabilities are not the best model, but they are useful here, just use a small helper (aliased to whatever you want) that have a hardcoded path to /proc/%u/io ,later give it CAP_DAC_OVERRIDE and CAP_SYS_PTRACE > So I guess I'm more interested in the read_byte, write_bytes and > cancelled_write_bytes fields (Per physical disk or filesystem > preferably.) > Would that give away any sensitive information? I'm not sure here, perhaps a matter of time before someone else interested pops up with a reaserch on this?! > If not maybe a separate /proc/PID/dio can be created to show only > these fields. Hmm, you could try if you think that it can be accepted! but do know that these days new procfs features are rare unless they are justified I don't know what others think about this. > Thanks. > -Marcel > > > > > > Signed-off-by: Marcel Mol > > > --- > > > fs/proc/base.c | 4 ++-- > > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > > > diff --git a/fs/proc/base.c b/fs/proc/base.c > > > index 772efa4..7bd8dbe 100644 > > > --- a/fs/proc/base.c > > > +++ b/fs/proc/base.c > > > @@ -2563,7 +2563,7 @@ static const struct pid_entry tgid_base_stuff[] = { > > > REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations), > > > #endif > > > #ifdef CONFIG_TASK_IO_ACCOUNTING > > > - ONE("io", S_IRUSR, proc_tgid_io_accounting), > > > + ONE("io", S_IRUGO, proc_tgid_io_accounting), > > > #endif > > > #ifdef CONFIG_HARDWALL > > > ONE("hardwall", S_IRUGO, proc_pid_hardwall), > > > @@ -2904,7 +2904,7 @@ static const struct pid_entry tid_base_stuff[] = { > > > REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), > > > #endif > > > #ifdef CONFIG_TASK_IO_ACCOUNTING > > > - ONE("io", S_IRUSR, proc_tid_io_accounting), > > > + ONE("io", S_IRUGO, proc_tid_io_accounting), > > > #endif > > > #ifdef CONFIG_HARDWALL > > > ONE("hardwall", S_IRUGO, proc_pid_hardwall), > > > -- > > > 1.9.3 > > > > > > > > > > -- > > Djalal Harouni > > http://opendz.org > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > Please read the FAQ at http://www.tux.org/lkml/ > > -- > ======-------- Marcel J.E. Mol MESA Consulting B.V. > =======--------- ph. +31-(0)6-54724868 P.O. Box 112 > =======--------- marcel@mesa.nl 2630 AC Nootdorp > __==== www.mesa.nl ---____U_n_i_x______I_n_t_e_r_n_e_t____ The Netherlands ____ > They couldn't think of a number, Linux user 1148 -- counter.li.org > so they gave me a name! -- Rupert Hine -- www.ruperthine.com -- Djalal Harouni http://opendz.org -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/