svn commit: r273958 - head/sys/dev/random

[Adrian Chadd]

Woo, this fixed the embedded boot! Thanks!



-adrian

On 1 November 2014 19:01, Dag-Erling Smørgrav <des at freebsd.org> wrote:
> Author: des
> Date: Sun Nov  2 02:01:55 2014
> New Revision: 273958
> URL: https://svnweb.freebsd.org/changeset/base/273958
>
> Log:
>   Restore the auto-reseed logic, but move it to a much later point,
>   immediately before kick_init.
>
>   Approved by:  so (self)
>
> Modified:
>   head/sys/dev/random/random_adaptors.c
>   head/sys/dev/random/yarrow.c
>
> Modified: head/sys/dev/random/random_adaptors.c
> ==============================================================================
> --- head/sys/dev/random/random_adaptors.c       Sun Nov  2 01:47:27 2014        (r273957)
> +++ head/sys/dev/random/random_adaptors.c       Sun Nov  2 02:01:55 2014        (r273958)
> @@ -447,30 +447,8 @@ random_adaptors_deinit(void)
>  }
>
>  /*
> - * First seed.
> - *
> - * NB! NB! NB!
> - * NB! NB! NB!
> - *
> - * It turns out this is bloody dangerous. I was fiddling with code elsewhere
> - * and managed to get conditions where a safe (i.e. seeded) entropy device should
> - * not have been possible. This managed to hide that by unblocking the device anyway.
> - * As crap randomness is not directly distinguishable from good randomness, this
> - * could have gone unnoticed for quite a while.
> - *
> - * NB! NB! NB!
> - * NB! NB! NB!
> - *
> - * Very luckily, the probe-time entropy is very nearly good enough to cause a
> - * first seed all of the time, and the default settings for other entropy
> - * harvesting causes a proper, safe, first seed (unblock) in short order after that.
> - *
> - * That said, the below would be useful where folks are more concerned with
> - * a quick start than with extra paranoia in a low-entropy environment.
> - *
> - * markm - October 2013.
> + * Reseed the active adaptor shortly before starting init(8).
>   */
> -#ifdef RANDOM_AUTOSEED
>  /* ARGSUSED */
>  static void
>  random_adaptors_seed(void *unused __unused)
> @@ -484,6 +462,5 @@ random_adaptors_seed(void *unused __unus
>
>         arc4rand(NULL, 0, 1);
>  }
> -SYSINIT(random_seed, SI_SUB_INTRINSIC_POST, SI_ORDER_LAST,
> -    random_adaptors_reseed, NULL);
> -#endif /*  RANDOM_AUTOSEED */
> +SYSINIT(random_seed, SI_SUB_KTHREAD_INIT, SI_ORDER_FIRST,
> +    random_adaptors_seed, NULL);
>
> Modified: head/sys/dev/random/yarrow.c
> ==============================================================================
> --- head/sys/dev/random/yarrow.c        Sun Nov  2 01:47:27 2014        (r273957)
> +++ head/sys/dev/random/yarrow.c        Sun Nov  2 02:01:55 2014        (r273958)
> @@ -508,7 +508,9 @@ void
>  random_yarrow_reseed(void)
>  {
>
> +       mtx_lock(&random_reseed_mtx);
>         reseed(SLOW);
> +       mtx_unlock(&random_reseed_mtx);
>  }
>
>  int
>