From: Noah Meyerhans <noahm@debian.org>
To: Greg KH <gregkh@linuxfoundation.org>
Cc: stable@vger.kernel.org, Theodore Ts'o <tytso@mit.edu>,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: Please apply 50ee7529ec45 ("random: try to actively add entropy rather than passively wait for it") to 4.19.y
Date: Tue, 28 Jan 2020 14:34:37 -0500 [thread overview]
Message-ID: <20200128193437.GA18426@morgul.net> (raw)
In-Reply-To: <20200128075223.GD2105706@kroah.com>
On Tue, Jan 28, 2020 at 08:52:23AM +0100, Greg KH wrote:
> > As detailed in https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=948519 and
> > https://wiki.debian.org/BoottimeEntropyStarvation, lack of boot-time entropy
> > can contribute to multi-minute pauses during system initialization in some
> > hardware configurations. While userspace workarounds, e.g. haveged, are
> > documented, the in-kernel jitter entropy collector eliminates the need for such
> > workarounds.
> >
> > It cherry-picks cleanly to 4.19.y and 4.14.y. I'm particularly interested
> > in the former.
> >
> > Thanks for considering this.
>
> Please cc: the developers of that commit, and the maintainer of that
> code, and we will be glad to consider it if they agree it is viable for
> those kernels.
Added torvalds and tytso to the CC list. Linus and Ted, what do you
think of the idea of applying 50ee7529ec45 ("random: try to actively add
entropy rather than passively wait for it") to the 4.19.y and 4.14.y
kernels?
> Personally, this looks like a "new feature" to me, if you really need
> this, what is preventing you from moving to a newer kernel version?
From a personal perspective, I'm fine with moving to a newer kernel, but
for distributions it's not that simple. The fact is, at the moment, the
current state of boot time entropy on systems running stable kernels on
systems without an HRNG-backed entropy source has lead to all manner of
workarounds being deployed. While some of the workarounds may be fine,
others may be quite a bit less safe. At least with the in-kernel jitter
entropy collector we can make things consistent.
Thanks
noah
next prev parent reply other threads:[~2020-01-28 19:34 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-27 23:02 Please apply 50ee7529ec45 ("random: try to actively add entropy rather than passively wait for it") to 4.19.y Noah Meyerhans
2020-01-28 7:52 ` Greg KH
2020-01-28 19:34 ` Noah Meyerhans [this message]
2020-01-28 19:59 ` Linus Torvalds
2020-01-30 0:39 ` Theodore Y. Ts'o
2020-01-30 14:49 ` Greg KH
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