Re: Linux messages full of `random: get_random_u32 called from`

From: Theodore Y. Ts'o
Date: Sun Apr 29 2018 - 16:08:58 EST


On Sun, Apr 29, 2018 at 11:30:57AM -0700, Sultan Alsawaf wrote:
>
> Mind you, this laptop has a 45W CPU, so power savings were definitely not
> considered in its design. Do you have any machines that can provide enough
> boot entropy to satisfy crng init without requiring user-provided entropy?

My 2018 Dell XPS 13 laptop, running "egrep '(random|EXT4)' /var/log/kern.log":

Apr 24 17:05:01 cwcc kernel: [ 0.000000] random: get_random_bytes called from start_kernel+0x83/0x500 with crng_init=0
Apr 24 17:05:01 cwcc kernel: [ 1.363383] random: fast init done
Apr 24 17:05:01 cwcc kernel: [ 3.567432] random: lvm: uninitialized urandom read (4 bytes read)
Apr 24 17:05:01 cwcc kernel: [ 3.593132] random: lvm: uninitialized urandom read (4 bytes read)
Apr 24 17:05:01 cwcc kernel: [ 7.584838] random: cryptsetup: uninitialized urandom read (2 bytes read)
Apr 24 17:05:01 cwcc kernel: [ 7.600685] random: cryptsetup: uninitialized urandom read (2 bytes read)
Apr 24 17:05:01 cwcc kernel: [ 7.803194] random: cryptsetup: uninitialized urandom read (2 bytes read)
Apr 24 17:05:01 cwcc kernel: [ 7.831050] random: lvm: uninitialized urandom read (4 bytes read)
Apr 24 17:05:01 cwcc kernel: [ 7.851884] random: lvm: uninitialized urandom read (4 bytes read)
Apr 24 17:05:01 cwcc kernel: [ 7.875382] random: lvm: uninitialized urandom read (2 bytes read)
Apr 24 17:05:01 cwcc kernel: [ 8.162552] EXT4-fs (dm-1): mounted filesystem with ordered data mode. Opts: (null)
Apr 24 17:05:01 cwcc kernel: [ 8.646497] random: crng init done

- Ted