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

[Andrey Chernov]

> 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;
 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();

-- 
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