Re: [PATCH -v5] random: introduce getrandom(2) system call

From: Andy Lutomirski
Date: Thu Jul 24 2014 - 11:22:08 EST


On Thu, Jul 24, 2014 at 8:18 AM, Henrique de Moraes Holschuh
<hmh@xxxxxxxxxx> wrote:
> On Thu, 24 Jul 2014, Theodore Ts'o wrote:
>> ERRORS
>> EINVAL An invalid flag was passed to getrandom(2)
>>
>> EFAULT buf is outside the accessible address space.
>>
>> EAGAIN The requested entropy was not available, and
>> getentropy(2) would have blocked if GRND_BLOCK flag
>> was set.
>>
>> EINTR While blocked waiting for entropy, the call was
>> interrupted by a signal handler; see the description
>> of how interrupted read(2) calls on "slow" devices
>> are handled with and without the SA_RESTART flag
>> in the signal(7) man page.
>
> Should we add E<SOMETHING> to be able to deny access to GRND_RANDOM or some
> future extension ?

This might actually be needed sooner rather than later. There are
programs that use containers and intentionally don't pass /dev/random
through into the container. I know that Sandstorm does this, and I
wouldn't be surprised if other things (Docker?) do the same thing.

--Andy
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