2022-05-02 23:20:23

by Jason A. Donenfeld

[permalink] [raw]
Subject: Re: [PATCH 2/2] random: add fork_event sysctl for polling VM forks

On Mon, May 02, 2022 at 08:34:38PM +0200, Alexander Graf wrote:
> Michael, since we already changed the CID in the spec, can we add a
> property to the device that indicates the first 4 bytes of the UUID will
> always be different between parent and child?
>
> That should give us the ability to mmap the vmgenid directly to user
> space and act based on a simple u32 compare for clone notification, no?

That is not a good idea. We want an _additional_ 4 bytes, so that we can
keep the first 16 bytes (128 bits) as a kernel space secret.

Jason