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