linux-kernel - Re: Entropy poolsize

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Message-ID: <AANLkTikVrqXlSEALYzKMZtQZY9U6IUtr6nmUwGwbyG6T@mail.gmail.com>
Date:	Tue, 22 Jun 2010 19:21:49 -0400
From:	Weedy <weedy2887@...il.com>
To:	linux-kernel@...r.kernel.org
Subject: Re: Entropy poolsize

Man I need to remember to hit reply-to-all

On Mon, Jun 21, 2010 at 3:56 PM, Randy Dunlap <randy.dunlap@...cle.com> wrote:
> On 06/21/10 12:48, Weedy wrote:
>> On Mon, Jun 21, 2010 at 11:51 AM, Randy Dunlap <randy.dunlap@...cle.com> wrote:
>>> On Mon, 21 Jun 2010 09:58:16 -0400 Weedy wrote:
>>>
>>>> I know grsecurity has a option for this but I don't want to patch my
>>>> kernel with it at this time. I have been poking around random.c but I
>>>> can't seem to figure out where .poolsize is assigned it's value and
>>>> how to increase it.
>>>>
>>>> If someone could point it out that would be nice.
>>>>
>>>> Thank you for your time.
>>>> --
>>>
>>> Do you mean this one in drivers/char/random.c or something else?
>>>
>>> static int sysctl_poolsize = INPUT_POOL_WORDS * 32;
>>>
>>> It's a sysctl, so it is tunable.
>> It's locked, some kind of security risk many kernels ago. I'll try
>> changing that but I thought I tried it once before.
>
> Ah, it's mode is 0444 (read-only).  Sorry I missed that piece.
> Sure, you could change the mode for your own use (rebuild the kernel).

 # cat /proc/sys/kernel/random/poolsize
16384
cat /proc/sys/kernel/random/entropy_avail
4096

I guess there is more to it.
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