public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Cyril Hrubis <chrubis@suse.cz>
To: Lukasz Majewski <lukma@denx.de>
Cc: Andrei Vagin <avagin@gmail.com>, Dmitry Safonov <dima@arista.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	GNU C Library <libc-alpha@sourceware.org>,
	linux-kernel@vger.kernel.org
Subject: Re: [Y2038][time namespaces] Question regarding CLOCK_REALTIME support plans in Linux time namespaces
Date: Fri, 30 Oct 2020 14:58:16 +0100	[thread overview]
Message-ID: <20201030135816.GA1790@yuki.lan> (raw)
In-Reply-To: <20201030110229.43f0773b@jawa>

Hi!
> I do have a question regarding the Linux time namespaces in respect of
> adding support for virtualizing the CLOCK_REALTIME.
> 
> According to patch description [1] and time_namespaces documentation
> [2] the CLOCK_REALTIME is not supported (for now?) to avoid complexity
> and overhead in the kernel.
> 
> Is there any plan to add support for it in a near future?
> 
> Why I'm asking? 
> 
> It looks like this kernel feature (with CLOCK_REALTIME support
> available) would be very helpful for testing Y2038 compliance for e.g.
> glibc 32 bit ports.
> 
> To be more specific - it would be possible to modify time after time_t
> 32 bit overflow (i.e. Y2038 bug) on the process running Y2038
> regression tests on the host system (64 bit one). By using Linux time
> namespaces the system time will not be affected in any way.

And what's exactly wrong with moving the system time forward for a
duration of the test?

-- 
Cyril Hrubis
chrubis@suse.cz

  parent reply	other threads:[~2020-10-30 13:57 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-30 10:02 [Y2038][time namespaces] Question regarding CLOCK_REALTIME support plans in Linux time namespaces Lukasz Majewski
2020-10-30 13:08 ` Thomas Gleixner
2020-10-30 15:43   ` Lukasz Majewski
2020-10-30 13:58 ` Cyril Hrubis [this message]
2020-10-30 14:02   ` Zack Weinberg
2020-10-30 15:10     ` Thomas Gleixner
2020-10-30 16:58       ` Carlos O'Donell
2020-10-30 20:06         ` Thomas Gleixner
2020-10-30 22:19           ` Carlos O'Donell
2020-10-31  1:38             ` Thomas Gleixner
2020-11-03 12:43               ` Cyril Hrubis
2020-11-05 17:25               ` Carlos O'Donell
2020-11-07  0:47                 ` Thomas Gleixner
2020-11-19 18:37                   ` Carlos O'Donell
2020-11-20  0:14                     ` Thomas Gleixner
2020-11-25 17:06                       ` Petr Špaček
2020-11-25 20:37                       ` Carlos O'Donell
2020-11-26  0:17                         ` Thomas Gleixner
2020-11-26  3:05                           ` Carlos O'Donell
2020-11-26  8:21                             ` Andreas Schwab
2020-11-14 10:25 ` Pavel Machek

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20201030135816.GA1790@yuki.lan \
    --to=chrubis@suse.cz \
    --cc=avagin@gmail.com \
    --cc=dima@arista.com \
    --cc=libc-alpha@sourceware.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=lukma@denx.de \
    --cc=tglx@linutronix.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox