svn commit: r230230 - head/sys/dev/random

[John Baldwin]

On Thursday, January 26, 2012 10:56:27 am Andrey Chernov wrote:
> > On Thu, Jan 26, 2012 at 08:39:07AM -0500, John Baldwin wrote:
> > > 		atomic_cmpset_int(&iniseed_state, ARC4_ENTER_NONE, 
ARC4_ENTER_HAVE);
> > > 		break;
> 
> Updated version (I hope, final):
> 
> --- sys/libkern.h.old	2012-01-16 07:15:12.000000000 +0400
> +++ sys/libkern.h	2012-01-26 19:38:06.000000000 +0400
> @@ -72,6 +72,8 @@ static __inline quad_t qabs(quad_t a) { 
>  
>  /* Prototypes for non-quad routines. */
>  struct malloc_type;
> +enum 	arc4_is { ARC4_ENTR_NONE, ARC4_ENTR_HAVE, ARC4_ENTR_DONE };
> +extern volatile enum arc4_is arc4rand_iniseed_state;

Atomics don't operate on enums.  You'll need to make it an int and just use 
#define's for the 3 states.

>  uint32_t arc4random(void);
>  void	 arc4rand(void *ptr, u_int len, int reseed);
>  int	 bcmp(const void *, const void *, size_t);
> --- dev/random/randomdev_soft.c.old	2011-03-02 01:42:19.000000000 +0300
> +++ dev/random/randomdev_soft.c	2012-01-26 19:35:12.000000000 +0400
> @@ -366,6 +366,8 @@ random_yarrow_unblock(void)
>  		selwakeuppri(&random_systat.rsel, PUSER);
>  		wakeup(&random_systat);
>  	}
> +	(void)atomic_cmpset_int(&arc4rand_iniseed_state,
> +				ARC4_ENTR_NONE, ARC4_ENTR_HAVE);
>  }
>  
>  static int
> --- libkern/arc4random.c.old	2008-08-08 01:51:09.000000000 +0400
> +++ libkern/arc4random.c	2012-01-26 19:43:31.000000000 +0400
> @@ -24,6 +24,7 @@ __FBSDID("$FreeBSD: src/sys/libkern/arc4
>  #define	ARC4_RESEED_SECONDS 300
>  #define	ARC4_KEYBYTES (256 / 8)
>  
> +volatile enum arc4_is arc4rand_iniseed_state = ARC4_ENTR_NONE;
>  static u_int8_t arc4_i, arc4_j;
>  static int arc4_numruns = 0;
>  static u_int8_t arc4_sbox[256];
> @@ -130,7 +131,9 @@ arc4rand(void *ptr, u_int len, int resee
>  	struct timeval tv;
>  
>  	getmicrouptime(&tv);
> -	if (reseed || 
> +	if (atomic_cmpset_int(&arc4rand_iniseed_state,
> +			      ARC4_ENTR_HAVE, ARC4_ENTR_DONE) ||
> +	   reseed ||
>  	   (arc4_numruns > ARC4_RESEED_BYTES) ||
>  	   (tv.tv_sec > arc4_t_reseed))
>  		arc4_randomstir();

I think the rest of this is fine.

-- 
John Baldwin