Index: head/sys/libkern/arc4random.c
===================================================================
--- head/sys/libkern/arc4random.c	(revision 309142)
+++ head/sys/libkern/arc4random.c	(revision 309143)
@@ -1,150 +1,193 @@
 /*-
  * THE BEER-WARE LICENSE
  *
  * <dan@FreeBSD.ORG> wrote this file.  As long as you retain this notice you
  * can do whatever you want with this stuff.  If we meet some day, and you
  * think this stuff is worth it, you can buy me a beer in return.
  *
  * Dan Moschuk
  */
 
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
 #include <sys/types.h>
 #include <sys/param.h>
 #include <sys/kernel.h>
 #include <sys/random.h>
 #include <sys/libkern.h>
 #include <sys/lock.h>
 #include <sys/mutex.h>
 #include <sys/time.h>
+#include <sys/smp.h>
+#include <sys/malloc.h>
 
 #define	ARC4_RESEED_BYTES 65536
 #define	ARC4_RESEED_SECONDS 300
 #define	ARC4_KEYBYTES 256
 
 int 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];
-static time_t arc4_t_reseed;
-static struct mtx arc4_mtx;
+MALLOC_DEFINE(M_ARC4RANDOM, "arc4random", "arc4random structures");
 
-static u_int8_t arc4_randbyte(void);
+struct arc4_s {
+	u_int8_t i, j;
+	int numruns;
+	u_int8_t sbox[256];
+	time_t t_reseed;
 
+	struct mtx mtx;
+};
+
+static struct arc4_s *arc4inst = NULL;
+
+#define ARC4_FOREACH(_arc4) \
+	for (_arc4 = &arc4inst[0]; _arc4 <= &arc4inst[mp_maxid]; _arc4++)
+
+static u_int8_t arc4_randbyte(struct arc4_s *arc4);
+
 static __inline void
 arc4_swap(u_int8_t *a, u_int8_t *b)
 {
 	u_int8_t c;
 
 	c = *a;
 	*a = *b;
 	*b = c;
 }	
 
 /*
  * Stir our S-box.
  */
 static void
-arc4_randomstir(void)
+arc4_randomstir(struct arc4_s* arc4)
 {
 	u_int8_t key[ARC4_KEYBYTES];
 	int n;
 	struct timeval tv_now;
 
 	/*
 	 * XXX: FIX!! This isn't brilliant. Need more confidence.
 	 * This returns zero entropy before random(4) is seeded.
 	 */
 	(void)read_random(key, ARC4_KEYBYTES);
 	getmicrouptime(&tv_now);
-	mtx_lock(&arc4_mtx);
+	mtx_lock(&arc4->mtx);
 	for (n = 0; n < 256; n++) {
-		arc4_j = (arc4_j + arc4_sbox[n] + key[n]) % 256;
-		arc4_swap(&arc4_sbox[n], &arc4_sbox[arc4_j]);
+		arc4->j = (arc4->j + arc4->sbox[n] + key[n]) % 256;
+		arc4_swap(&arc4->sbox[n], &arc4->sbox[arc4->j]);
 	}
-	arc4_i = arc4_j = 0;
+	arc4->i = arc4->j = 0;
 	/* Reset for next reseed cycle. */
-	arc4_t_reseed = tv_now.tv_sec + ARC4_RESEED_SECONDS;
-	arc4_numruns = 0;
+	arc4->t_reseed = tv_now.tv_sec + ARC4_RESEED_SECONDS;
+	arc4->numruns = 0;
 	/*
 	 * Throw away the first N words of output, as suggested in the
 	 * paper "Weaknesses in the Key Scheduling Algorithm of RC4"
 	 * by Fluher, Mantin, and Shamir.  (N = 256 in our case.)
 	 *
 	 * http://dl.acm.org/citation.cfm?id=646557.694759
 	 */
 	for (n = 0; n < 256*4; n++)
-		arc4_randbyte();
-	mtx_unlock(&arc4_mtx);
+		arc4_randbyte(arc4);
+
+	mtx_unlock(&arc4->mtx);
 }
 
 /*
  * Initialize our S-box to its beginning defaults.
  */
 static void
 arc4_init(void)
 {
+	struct arc4_s *arc4;
 	int n;
 
-	mtx_init(&arc4_mtx, "arc4_mtx", NULL, MTX_DEF);
-	arc4_i = arc4_j = 0;
-	for (n = 0; n < 256; n++)
-		arc4_sbox[n] = (u_int8_t) n;
+	arc4inst = malloc((mp_maxid + 1) * sizeof(struct arc4_s),
+			M_ARC4RANDOM, M_NOWAIT | M_ZERO);
+	KASSERT(arc4inst != NULL, ("arc4_init: memory allocation error"));
 
-	arc4_t_reseed = 0;
+	ARC4_FOREACH(arc4) {
+		mtx_init(&arc4->mtx, "arc4_mtx", NULL, MTX_DEF);
+
+		arc4->i = arc4->j = 0;
+		for (n = 0; n < 256; n++)
+			arc4->sbox[n] = (u_int8_t) n;
+
+		arc4->t_reseed = -1;
+		arc4->numruns = 0;
+	}
 }
+SYSINIT(arc4, SI_SUB_LOCK, SI_ORDER_ANY, arc4_init, NULL);
 
-SYSINIT(arc4_init, SI_SUB_LOCK, SI_ORDER_ANY, arc4_init, NULL);
 
+static void
+arc4_uninit(void)
+{
+	struct arc4_s *arc4;
+
+	ARC4_FOREACH(arc4) {
+		mtx_destroy(&arc4->mtx);
+	}
+
+	free(arc4inst, M_ARC4RANDOM);
+}
+
+SYSUNINIT(arc4, SI_SUB_LOCK, SI_ORDER_ANY, arc4_uninit, NULL);
+
+
 /*
  * Generate a random byte.
  */
 static u_int8_t
-arc4_randbyte(void)
+arc4_randbyte(struct arc4_s *arc4)
 {
 	u_int8_t arc4_t;
 
-	arc4_i = (arc4_i + 1) % 256;
-	arc4_j = (arc4_j + arc4_sbox[arc4_i]) % 256;
+	arc4->i = (arc4->i + 1) % 256;
+	arc4->j = (arc4->j + arc4->sbox[arc4->i]) % 256;
 
-	arc4_swap(&arc4_sbox[arc4_i], &arc4_sbox[arc4_j]);
+	arc4_swap(&arc4->sbox[arc4->i], &arc4->sbox[arc4->j]);
 
-	arc4_t = (arc4_sbox[arc4_i] + arc4_sbox[arc4_j]) % 256;
-	return arc4_sbox[arc4_t];
+	arc4_t = (arc4->sbox[arc4->i] + arc4->sbox[arc4->j]) % 256;
+	return arc4->sbox[arc4_t];
 }
 
 /*
  * MPSAFE
  */
 void
 arc4rand(void *ptr, u_int len, int reseed)
 {
 	u_char *p;
 	struct timeval tv;
+	struct arc4_s *arc4;
 
+	if (reseed || atomic_cmpset_int(&arc4rand_iniseed_state,
+			ARC4_ENTR_HAVE, ARC4_ENTR_SEED)) {
+		ARC4_FOREACH(arc4)
+			arc4_randomstir(arc4);
+	}
+
+	arc4 = &arc4inst[curcpu];
 	getmicrouptime(&tv);
-	if (atomic_cmpset_int(&arc4rand_iniseed_state, ARC4_ENTR_HAVE,
-	    ARC4_ENTR_SEED) || reseed ||
-	   (arc4_numruns > ARC4_RESEED_BYTES) ||
-	   (tv.tv_sec > arc4_t_reseed))
-		arc4_randomstir();
+	if ((arc4->numruns > ARC4_RESEED_BYTES) ||
+		(tv.tv_sec > arc4->t_reseed))
+		arc4_randomstir(arc4);
 
-	mtx_lock(&arc4_mtx);
-	arc4_numruns += len;
+	mtx_lock(&arc4->mtx);
+	arc4->numruns += len;
 	p = ptr;
 	while (len--)
-		*p++ = arc4_randbyte();
-	mtx_unlock(&arc4_mtx);
+		*p++ = arc4_randbyte(arc4);
+	mtx_unlock(&arc4->mtx);
 }
 
 uint32_t
 arc4random(void)
 {
 	uint32_t ret;
 
 	arc4rand(&ret, sizeof ret, 0);
 	return ret;
 }