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Date:   Sun, 29 Apr 2018 16:08:46 -0400
From:   "Theodore Y. Ts'o" <tytso@mit.edu>
To:     Sultan Alsawaf <sultanxda@gmail.com>
Cc:     linux-kernel@vger.kernel.org, Jann Horn <jannh@google.com>
Subject: Re: Linux messages full of `random: get_random_u32 called from`
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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