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Date:      Wed, 25 Jan 2012 19:16:41 +0000
From:      Mark Murray <markm@FreeBSD.org>
To:        Andrey Chernov <ache@FreeBSD.ORG>
Cc:        svn-src-head@FreeBSD.ORG, svn-src-all@FreeBSD.ORG, src-committers@FreeBSD.ORG
Subject:   Re: svn commit: r230230 - head/sys/dev/random
Message-ID:  <E1Rq8Kn-000Ms9-KE@groundzero.grondar.org>
In-Reply-To: <20120125140237.GA74896@vniz.net>
References:  <201201162018.q0GKIADK050161@svn.freebsd.org> <20120118061943.GA80874@vniz.net> <E1Rny2A-000C3x-O6@groundzero.grondar.org> <20120120055823.GA28177@vniz.net> <E1RoG98-000DiP-0Y@groundzero.grondar.org> <20120120215649.GA40016@vniz.net> <E1Rp0lq-000Gly-FT@groundzero.grondar.org> <20120122185545.GA11874@vniz.net> <E1Rp5Bn-000HBl-2P@groundzero.grondar.org> <20120125140237.GA74896@vniz.net>

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Andrey Chernov writes:
> On Sun, Jan 22, 2012 at 09:43:02PM +0000, Mark Murray wrote:
> > > Thanx for review! I'll send final version to this thread a bit 
> > > later when I'll find more free time.
> 
> Final, unless something else noticed.

Cool. NOTE: I am only eyeballing this, not testing it.

> --- sys/libkern.h.bak	2012-01-16 07:15:12.000000000 +0400
> +++ sys/libkern.h	2012-01-25 17:31:49.000000000 +0400
> @@ -72,6 +72,7 @@ static __inline quad_t qabs(quad_t a) { 
>  
>  /* Prototypes for non-quad routines. */
>  struct malloc_type;
> +extern int arc4rand_iniseed_state;
>  uint32_t arc4random(void);
>  void	 arc4rand(void *ptr, u_int len, int reseed);
>  int	 bcmp(const void *, const void *, size_t);

Fine.

> --- dev/random/randomdev_soft.c.bak	2011-03-02 01:42:19.000000000 +0300
> +++ dev/random/randomdev_soft.c	2012-01-25 17:28:19.000000000 +0400
> @@ -366,6 +366,8 @@ random_yarrow_unblock(void)
>  		selwakeuppri(&random_systat.rsel, PUSER);
>  		wakeup(&random_systat);
>  	}
> +	if (arc4rand_iniseed_state == 0)
> +		arc4rand_iniseed_state = 1;
>  }
>  
>  static int

I thought you were going to do this as a function? It would be
slightly neater to do it that way.

> --- libkern/arc4random.c.bak	2008-08-08 01:51:09.000000000 +0400
> +++ libkern/arc4random.c	2012-01-25 17:30:30.000000000 +0400
> @@ -24,6 +24,8 @@ __FBSDID("$FreeBSD: src/sys/libkern/arc4
>  #define	ARC4_RESEED_SECONDS 300
>  #define	ARC4_KEYBYTES (256 / 8)
>  
> +int arc4rand_iniseed_state = 0;
> +
>  static u_int8_t arc4_i, arc4_j;
>  static int arc4_numruns = 0;
>  static u_int8_t arc4_sbox[256];
> @@ -74,6 +76,8 @@ arc4_randomstir (void)
>  	/* Reset for next reseed cycle. */
>  	arc4_t_reseed = tv_now.tv_sec + ARC4_RESEED_SECONDS;
>  	arc4_numruns = 0;
> +	if (arc4rand_iniseed_state == 1)
> +		arc4rand_iniseed_state = -1;
>  
>  	/*
>  	 * Throw away the first N words of output, as suggested in the
> @@ -130,7 +134,7 @@ arc4rand(void *ptr, u_int len, int resee
>  	struct timeval tv;
>  
>  	getmicrouptime(&tv);
> -	if (reseed || 
> +	if (reseed || arc4rand_iniseed_state == 1 ||
>  	   (arc4_numruns > ARC4_RESEED_BYTES) ||
>  	   (tv.tv_sec > arc4_t_reseed))
>  		arc4_randomstir();

Looks good! Are you sure this needs no locking or volatile
variables?

M
--
Mark R V Murray
Cert APS(Open) Dip Phys(Open) BSc Open(Open) BSc(Hons)(Open)
Pi: 132511160




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