Get the full set of PRNG functions in <stdlib.h>

Bug: https://code.google.com/p/android/issues/detail?id=58888
Change-Id: I435250bdae302e8bd7e29977d0fde7b9afbfca5e
diff --git a/libc/Android.mk b/libc/Android.mk
index cd5cb02..30e6419 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -265,6 +265,7 @@
 
 libc_upstream_netbsd_src_files := \
     upstream-netbsd/common/lib/libc/hash/sha1/sha1.c \
+    upstream-netbsd/common/lib/libc/stdlib/random.c \
     upstream-netbsd/lib/libc/gen/ftw.c \
     upstream-netbsd/lib/libc/gen/nftw.c \
     upstream-netbsd/lib/libc/gen/nice.c \
@@ -290,6 +291,8 @@
     upstream-netbsd/lib/libc/stdlib/mrand48.c \
     upstream-netbsd/lib/libc/stdlib/nrand48.c \
     upstream-netbsd/lib/libc/stdlib/_rand48.c \
+    upstream-netbsd/lib/libc/stdlib/rand.c \
+    upstream-netbsd/lib/libc/stdlib/rand_r.c \
     upstream-netbsd/lib/libc/stdlib/seed48.c \
     upstream-netbsd/lib/libc/stdlib/srand48.c \
     upstream-netbsd/lib/libc/stdlib/tdelete.c \
diff --git a/libc/include/stdlib.h b/libc/include/stdlib.h
index 0f862c3..0f985e2 100644
--- a/libc/include/stdlib.h
+++ b/libc/include/stdlib.h
@@ -105,20 +105,15 @@
 extern void arc4random_addrandom(unsigned char *, int);
 
 #define RAND_MAX 0x7fffffff
-static __inline__ int rand(void) {
-    return (int)lrand48();
-}
-static __inline__ void srand(unsigned int __s) {
-    srand48(__s);
-}
-static __inline__ long random(void)
-{
-    return lrand48();
-}
-static __inline__ void srandom(unsigned int __s)
-{
-    srand48(__s);
-}
+
+int rand(void);
+int rand_r(unsigned int*);
+void srand(unsigned int);
+
+char* initstate(unsigned int, char*, size_t);
+long random(void);
+char* setstate(char*);
+void srandom(unsigned int);
 
 /* Basic PTY functions.  These only work if devpts is mounted! */
 
diff --git a/libc/upstream-netbsd/common/lib/libc/stdlib/random.c b/libc/upstream-netbsd/common/lib/libc/stdlib/random.c
new file mode 100644
index 0000000..e7503c7
--- /dev/null
+++ b/libc/upstream-netbsd/common/lib/libc/stdlib/random.c
@@ -0,0 +1,530 @@
+/*	$NetBSD: random.c,v 1.4 2014/06/12 20:59:46 christos Exp $	*/
+
+/*
+ * Copyright (c) 1983, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if !defined(_KERNEL) && !defined(_STANDALONE)
+#include <sys/cdefs.h>
+#if defined(LIBC_SCCS) && !defined(lint)
+#if 0
+static char sccsid[] = "@(#)random.c	8.2 (Berkeley) 5/19/95";
+#else
+__RCSID("$NetBSD: random.c,v 1.4 2014/06/12 20:59:46 christos Exp $");
+#endif
+#endif /* LIBC_SCCS and not lint */
+
+#include "namespace.h"
+
+#include <assert.h>
+#include <errno.h>
+#include <stdlib.h>
+#include "reentrant.h"
+
+#ifdef __weak_alias
+__weak_alias(initstate,_initstate)
+__weak_alias(random,_random)
+__weak_alias(setstate,_setstate)
+__weak_alias(srandom,_srandom)
+#endif
+
+
+#ifdef _REENTRANT
+static mutex_t random_mutex = MUTEX_INITIALIZER;
+#endif
+#else
+#include <lib/libkern/libkern.h>
+#define mutex_lock(a)	(void)0
+#define mutex_unlock(a) (void)0
+#endif
+
+#ifndef SMALL_RANDOM
+static void srandom_unlocked(unsigned int);
+static long random_unlocked(void);
+
+#define USE_BETTER_RANDOM
+
+/*
+ * random.c:
+ *
+ * An improved random number generation package.  In addition to the standard
+ * rand()/srand() like interface, this package also has a special state info
+ * interface.  The initstate() routine is called with a seed, an array of
+ * bytes, and a count of how many bytes are being passed in; this array is
+ * then initialized to contain information for random number generation with
+ * that much state information.  Good sizes for the amount of state
+ * information are 32, 64, 128, and 256 bytes.  The state can be switched by
+ * calling the setstate() routine with the same array as was initiallized
+ * with initstate().  By default, the package runs with 128 bytes of state
+ * information and generates far better random numbers than a linear
+ * congruential generator.  If the amount of state information is less than
+ * 32 bytes, a simple linear congruential R.N.G. is used.
+ *
+ * Internally, the state information is treated as an array of ints; the
+ * zeroeth element of the array is the type of R.N.G. being used (small
+ * integer); the remainder of the array is the state information for the
+ * R.N.G.  Thus, 32 bytes of state information will give 7 ints worth of
+ * state information, which will allow a degree seven polynomial.  (Note:
+ * the zeroeth word of state information also has some other information
+ * stored in it -- see setstate() for details).
+ * 
+ * The random number generation technique is a linear feedback shift register
+ * approach, employing trinomials (since there are fewer terms to sum up that
+ * way).  In this approach, the least significant bit of all the numbers in
+ * the state table will act as a linear feedback shift register, and will
+ * have period 2^deg - 1 (where deg is the degree of the polynomial being
+ * used, assuming that the polynomial is irreducible and primitive).  The
+ * higher order bits will have longer periods, since their values are also
+ * influenced by pseudo-random carries out of the lower bits.  The total
+ * period of the generator is approximately deg*(2**deg - 1); thus doubling
+ * the amount of state information has a vast influence on the period of the
+ * generator.  Note: the deg*(2**deg - 1) is an approximation only good for
+ * large deg, when the period of the shift register is the dominant factor.
+ * With deg equal to seven, the period is actually much longer than the
+ * 7*(2**7 - 1) predicted by this formula.
+ *
+ * Modified 28 December 1994 by Jacob S. Rosenberg.
+ * The following changes have been made:
+ * All references to the type u_int have been changed to unsigned long.
+ * All references to type int have been changed to type long.  Other
+ * cleanups have been made as well.  A warning for both initstate and
+ * setstate has been inserted to the effect that on Sparc platforms
+ * the 'arg_state' variable must be forced to begin on word boundaries.
+ * This can be easily done by casting a long integer array to char *.
+ * The overall logic has been left STRICTLY alone.  This software was
+ * tested on both a VAX and Sun SpacsStation with exactly the same
+ * results.  The new version and the original give IDENTICAL results.
+ * The new version is somewhat faster than the original.  As the
+ * documentation says:  "By default, the package runs with 128 bytes of
+ * state information and generates far better random numbers than a linear
+ * congruential generator.  If the amount of state information is less than
+ * 32 bytes, a simple linear congruential R.N.G. is used."  For a buffer of
+ * 128 bytes, this new version runs about 19 percent faster and for a 16
+ * byte buffer it is about 5 percent faster.
+ *
+ * Modified 07 January 2002 by Jason R. Thorpe.
+ * The following changes have been made:
+ * All the references to "long" have been changed back to "int".  This
+ * fixes memory corruption problems on LP64 platforms.
+ */
+
+/*
+ * For each of the currently supported random number generators, we have a
+ * break value on the amount of state information (you need at least this
+ * many bytes of state info to support this random number generator), a degree
+ * for the polynomial (actually a trinomial) that the R.N.G. is based on, and
+ * the separation between the two lower order coefficients of the trinomial.
+ */
+#define	TYPE_0		0		/* linear congruential */
+#define	BREAK_0		8
+#define	DEG_0		0
+#define	SEP_0		0
+
+#define	TYPE_1		1		/* x**7 + x**3 + 1 */
+#define	BREAK_1		32
+#define	DEG_1		7
+#define	SEP_1		3
+
+#define	TYPE_2		2		/* x**15 + x + 1 */
+#define	BREAK_2		64
+#define	DEG_2		15
+#define	SEP_2		1
+
+#define	TYPE_3		3		/* x**31 + x**3 + 1 */
+#define	BREAK_3		128
+#define	DEG_3		31
+#define	SEP_3		3
+
+#define	TYPE_4		4		/* x**63 + x + 1 */
+#define	BREAK_4		256
+#define	DEG_4		63
+#define	SEP_4		1
+
+/*
+ * Array versions of the above information to make code run faster --
+ * relies on fact that TYPE_i == i.
+ */
+#define	MAX_TYPES	5		/* max number of types above */
+
+static const int degrees[MAX_TYPES] =	{ DEG_0, DEG_1, DEG_2, DEG_3, DEG_4 };
+static const int seps[MAX_TYPES] =	{ SEP_0, SEP_1, SEP_2, SEP_3, SEP_4 };
+
+/*
+ * Initially, everything is set up as if from:
+ *
+ *	initstate(1, &randtbl, 128);
+ *
+ * Note that this initialization takes advantage of the fact that srandom()
+ * advances the front and rear pointers 10*rand_deg times, and hence the
+ * rear pointer which starts at 0 will also end up at zero; thus the zeroeth
+ * element of the state information, which contains info about the current
+ * position of the rear pointer is just
+ *
+ *	MAX_TYPES * (rptr - state) + TYPE_3 == TYPE_3.
+ */
+
+/* LINTED */
+static int randtbl[DEG_3 + 1] = {
+	TYPE_3,
+#ifdef USE_BETTER_RANDOM
+	0x991539b1, 0x16a5bce3, 0x6774a4cd,
+	0x3e01511e, 0x4e508aaa, 0x61048c05,
+	0xf5500617, 0x846b7115, 0x6a19892c,
+	0x896a97af, 0xdb48f936, 0x14898454,
+	0x37ffd106, 0xb58bff9c, 0x59e17104,
+	0xcf918a49, 0x09378c83, 0x52c7a471,
+	0x8d293ea9, 0x1f4fc301, 0xc3db71be,
+	0x39b44e1c, 0xf8a44ef9, 0x4c8b80b1,
+	0x19edc328, 0x87bf4bdd, 0xc9b240e5,
+	0xe9ee4b1b, 0x4382aee7, 0x535b6b41,
+	0xf3bec5da,
+#else
+	0x9a319039, 0x32d9c024, 0x9b663182,
+	0x5da1f342, 0xde3b81e0, 0xdf0a6fb5,
+	0xf103bc02, 0x48f340fb, 0x7449e56b,
+	0xbeb1dbb0, 0xab5c5918, 0x946554fd,
+	0x8c2e680f, 0xeb3d799f, 0xb11ee0b7,
+	0x2d436b86, 0xda672e2a, 0x1588ca88,
+	0xe369735d, 0x904f35f7, 0xd7158fd6,
+	0x6fa6f051, 0x616e6b96, 0xac94efdc,
+	0x36413f93, 0xc622c298, 0xf5a42ab8,
+	0x8a88d77b, 0xf5ad9d0e, 0x8999220b,
+	0x27fb47b9,
+#endif /* USE_BETTER_RANDOM */
+};
+
+/*
+ * fptr and rptr are two pointers into the state info, a front and a rear
+ * pointer.  These two pointers are always rand_sep places aparts, as they
+ * cycle cyclically through the state information.  (Yes, this does mean we
+ * could get away with just one pointer, but the code for random() is more
+ * efficient this way).  The pointers are left positioned as they would be
+ * from the call
+ *
+ *	initstate(1, randtbl, 128);
+ *
+ * (The position of the rear pointer, rptr, is really 0 (as explained above
+ * in the initialization of randtbl) because the state table pointer is set
+ * to point to randtbl[1] (as explained below).
+ */
+static int *fptr = &randtbl[SEP_3 + 1];
+static int *rptr = &randtbl[1];
+
+/*
+ * The following things are the pointer to the state information table, the
+ * type of the current generator, the degree of the current polynomial being
+ * used, and the separation between the two pointers.  Note that for efficiency
+ * of random(), we remember the first location of the state information, not
+ * the zeroeth.  Hence it is valid to access state[-1], which is used to
+ * store the type of the R.N.G.  Also, we remember the last location, since
+ * this is more efficient than indexing every time to find the address of
+ * the last element to see if the front and rear pointers have wrapped.
+ */
+static int *state = &randtbl[1];
+static int rand_type = TYPE_3;
+static int rand_deg = DEG_3;
+static int rand_sep = SEP_3;
+static int *end_ptr = &randtbl[DEG_3 + 1];
+
+/*
+ * srandom:
+ *
+ * Initialize the random number generator based on the given seed.  If the
+ * type is the trivial no-state-information type, just remember the seed.
+ * Otherwise, initializes state[] based on the given "seed" via a linear
+ * congruential generator.  Then, the pointers are set to known locations
+ * that are exactly rand_sep places apart.  Lastly, it cycles the state
+ * information a given number of times to get rid of any initial dependencies
+ * introduced by the L.C.R.N.G.  Note that the initialization of randtbl[]
+ * for default usage relies on values produced by this routine.
+ */
+static void
+srandom_unlocked(unsigned int x)
+{
+	int i;
+
+	if (rand_type == TYPE_0)
+		state[0] = x;
+	else {
+		state[0] = x;
+		for (i = 1; i < rand_deg; i++) {
+#ifdef USE_BETTER_RANDOM
+			int x1, hi, lo, t;
+
+			/*
+			 * Compute x[n + 1] = (7^5 * x[n]) mod (2^31 - 1).
+			 * From "Random number generators: good ones are hard
+			 * to find", Park and Miller, Communications of the ACM,
+			 * vol. 31, no. 10,
+			 * October 1988, p. 1195.
+			 */
+			x1 = state[i - 1];
+			hi = x1 / 127773;
+			lo = x1 % 127773;
+			t = 16807 * lo - 2836 * hi;
+			if (t <= 0)
+				t += 0x7fffffff;
+			state[i] = t;
+#else
+			state[i] = 1103515245 * state[i - 1] + 12345;
+#endif /* USE_BETTER_RANDOM */
+		}
+		fptr = &state[rand_sep];
+		rptr = &state[0];
+		for (i = 0; i < 10 * rand_deg; i++)
+			(void)random_unlocked();
+	}
+}
+
+void
+srandom(unsigned int x)
+{
+
+	mutex_lock(&random_mutex);
+	srandom_unlocked(x);
+	mutex_unlock(&random_mutex);
+}
+
+/*
+ * initstate:
+ *
+ * Initialize the state information in the given array of n bytes for future
+ * random number generation.  Based on the number of bytes we are given, and
+ * the break values for the different R.N.G.'s, we choose the best (largest)
+ * one we can and set things up for it.  srandom() is then called to
+ * initialize the state information.
+ * 
+ * Note that on return from srandom(), we set state[-1] to be the type
+ * multiplexed with the current value of the rear pointer; this is so
+ * successive calls to initstate() won't lose this information and will be
+ * able to restart with setstate().
+ * 
+ * Note: the first thing we do is save the current state, if any, just like
+ * setstate() so that it doesn't matter when initstate is called.
+ *
+ * Returns a pointer to the old state.
+ *
+ * Note: The Sparc platform requires that arg_state begin on an int
+ * word boundary; otherwise a bus error will occur. Even so, lint will
+ * complain about mis-alignment, but you should disregard these messages.
+ */
+char *
+initstate(
+	unsigned int seed,		/* seed for R.N.G. */
+	char *arg_state,		/* pointer to state array */
+	size_t n)			/* # bytes of state info */
+{
+	void *ostate = (void *)(&state[-1]);
+	int *int_arg_state;
+
+	_DIAGASSERT(arg_state != NULL);
+
+	int_arg_state = (int *)(void *)arg_state;
+
+	mutex_lock(&random_mutex);
+	if (rand_type == TYPE_0)
+		state[-1] = rand_type;
+	else
+		state[-1] = MAX_TYPES * (int)(rptr - state) + rand_type;
+	if (n < BREAK_0) {
+		mutex_unlock(&random_mutex);
+		return (NULL);
+	} else if (n < BREAK_1) {
+		rand_type = TYPE_0;
+		rand_deg = DEG_0;
+		rand_sep = SEP_0;
+	} else if (n < BREAK_2) {
+		rand_type = TYPE_1;
+		rand_deg = DEG_1;
+		rand_sep = SEP_1;
+	} else if (n < BREAK_3) {
+		rand_type = TYPE_2;
+		rand_deg = DEG_2;
+		rand_sep = SEP_2;
+	} else if (n < BREAK_4) {
+		rand_type = TYPE_3;
+		rand_deg = DEG_3;
+		rand_sep = SEP_3;
+	} else {
+		rand_type = TYPE_4;
+		rand_deg = DEG_4;
+		rand_sep = SEP_4;
+	}
+	state = (int *) (int_arg_state + 1); /* first location */
+	end_ptr = &state[rand_deg];	/* must set end_ptr before srandom */
+	srandom_unlocked(seed);
+	if (rand_type == TYPE_0)
+		int_arg_state[0] = rand_type;
+	else
+		int_arg_state[0] = MAX_TYPES * (int)(rptr - state) + rand_type;
+	mutex_unlock(&random_mutex);
+	return((char *)ostate);
+}
+
+/*
+ * setstate:
+ *
+ * Restore the state from the given state array.
+ *
+ * Note: it is important that we also remember the locations of the pointers
+ * in the current state information, and restore the locations of the pointers
+ * from the old state information.  This is done by multiplexing the pointer
+ * location into the zeroeth word of the state information.
+ *
+ * Note that due to the order in which things are done, it is OK to call
+ * setstate() with the same state as the current state.
+ *
+ * Returns a pointer to the old state information.
+ *
+ * Note: The Sparc platform requires that arg_state begin on a long
+ * word boundary; otherwise a bus error will occur. Even so, lint will
+ * complain about mis-alignment, but you should disregard these messages.
+ */
+char *
+setstate(char *arg_state)		/* pointer to state array */
+{
+	int *new_state;
+	int type;
+	int rear;
+	void *ostate = (void *)(&state[-1]);
+
+	_DIAGASSERT(arg_state != NULL);
+
+	new_state = (int *)(void *)arg_state;
+	type = (int)(new_state[0] % MAX_TYPES);
+	rear = (int)(new_state[0] / MAX_TYPES);
+
+	mutex_lock(&random_mutex);
+	if (rand_type == TYPE_0)
+		state[-1] = rand_type;
+	else
+		state[-1] = MAX_TYPES * (int)(rptr - state) + rand_type;
+	switch(type) {
+	case TYPE_0:
+	case TYPE_1:
+	case TYPE_2:
+	case TYPE_3:
+	case TYPE_4:
+		rand_type = type;
+		rand_deg = degrees[type];
+		rand_sep = seps[type];
+		break;
+	default:
+		mutex_unlock(&random_mutex);
+		return (NULL);
+	}
+	state = (int *) (new_state + 1);
+	if (rand_type != TYPE_0) {
+		rptr = &state[rear];
+		fptr = &state[(rear + rand_sep) % rand_deg];
+	}
+	end_ptr = &state[rand_deg];		/* set end_ptr too */
+	mutex_unlock(&random_mutex);
+	return((char *)ostate);
+}
+
+/*
+ * random:
+ *
+ * If we are using the trivial TYPE_0 R.N.G., just do the old linear
+ * congruential bit.  Otherwise, we do our fancy trinomial stuff, which is
+ * the same in all the other cases due to all the global variables that have
+ * been set up.  The basic operation is to add the number at the rear pointer
+ * into the one at the front pointer.  Then both pointers are advanced to
+ * the next location cyclically in the table.  The value returned is the sum
+ * generated, reduced to 31 bits by throwing away the "least random" low bit.
+ *
+ * Note: the code takes advantage of the fact that both the front and
+ * rear pointers can't wrap on the same call by not testing the rear
+ * pointer if the front one has wrapped.
+ *
+ * Returns a 31-bit random number.
+ */
+static long
+random_unlocked(void)
+{
+	int i;
+	int *f, *r;
+
+	if (rand_type == TYPE_0) {
+		i = state[0];
+		state[0] = i = (i * 1103515245 + 12345) & 0x7fffffff;
+	} else {
+		/*
+		 * Use local variables rather than static variables for speed.
+		 */
+		f = fptr; r = rptr;
+		*f += *r;
+		/* chucking least random bit */
+		i = ((unsigned int)*f >> 1) & 0x7fffffff;
+		if (++f >= end_ptr) {
+			f = state;
+			++r;
+		}
+		else if (++r >= end_ptr) {
+			r = state;
+		}
+
+		fptr = f; rptr = r;
+	}
+	return(i);
+}
+
+long
+random(void)
+{
+	long r;
+
+	mutex_lock(&random_mutex);
+	r = random_unlocked();
+	mutex_unlock(&random_mutex);
+	return (r);
+}
+#else
+long
+random(void)
+{
+	static u_long randseed = 1;
+	long x, hi, lo, t;
+ 
+	/*
+	 * Compute x[n + 1] = (7^5 * x[n]) mod (2^31 - 1).
+	 * From "Random number generators: good ones are hard to find",
+	 * Park and Miller, Communications of the ACM, vol. 31, no. 10,
+	 * October 1988, p. 1195.
+	 */
+	x = randseed;
+	hi = x / 127773;
+	lo = x % 127773;
+	t = 16807 * lo - 2836 * hi;
+	if (t <= 0)
+		t += 0x7fffffff;
+	randseed = t;
+	return (t);
+}
+#endif /* SMALL_RANDOM */
diff --git a/libc/upstream-netbsd/lib/libc/stdlib/rand.c b/libc/upstream-netbsd/lib/libc/stdlib/rand.c
new file mode 100644
index 0000000..4909d14
--- /dev/null
+++ b/libc/upstream-netbsd/lib/libc/stdlib/rand.c
@@ -0,0 +1,57 @@
+/*	$NetBSD: rand.c,v 1.12 2012/06/25 22:32:45 abs Exp $	*/
+
+/*-
+ * Copyright (c) 1990, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+#if defined(LIBC_SCCS) && !defined(lint)
+#if 0
+static char sccsid[] = "@(#)rand.c	8.1 (Berkeley) 6/14/93";
+#else
+__RCSID("$NetBSD: rand.c,v 1.12 2012/06/25 22:32:45 abs Exp $");
+#endif
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/types.h>
+#include <stdlib.h>
+
+static u_long next = 1;
+
+int
+rand(void)
+{
+	/* LINTED integer overflow */
+	return (int)((next = next * 1103515245 + 12345) % ((u_long)RAND_MAX + 1));
+}
+
+void
+srand(u_int seed)
+{
+	next = seed;
+}
diff --git a/libc/upstream-netbsd/lib/libc/stdlib/rand_r.c b/libc/upstream-netbsd/lib/libc/stdlib/rand_r.c
new file mode 100644
index 0000000..272b2bd
--- /dev/null
+++ b/libc/upstream-netbsd/lib/libc/stdlib/rand_r.c
@@ -0,0 +1,51 @@
+/*	$NetBSD: rand_r.c,v 1.6 2012/06/25 22:32:45 abs Exp $	*/
+
+/*-
+ * Copyright (c) 1990 The Regents of the University of California.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+#if defined(LIBC_SCCS) && !defined(lint)
+#if 0
+static char *sccsid = "from: @(#)rand.c	5.6 (Berkeley) 6/24/91";
+#else
+__RCSID("$NetBSD: rand_r.c,v 1.6 2012/06/25 22:32:45 abs Exp $");
+#endif
+#endif /* LIBC_SCCS and not lint */
+
+#include <assert.h>
+#include <errno.h>
+#include <stdlib.h>
+
+int
+rand_r(unsigned int *seed)
+{
+	_DIAGASSERT(seed != NULL);
+
+	return ((*seed = *seed * 1103515245 + 12345) & RAND_MAX);
+}
diff --git a/tests/stdlib_test.cpp b/tests/stdlib_test.cpp
index 978a60f..7c86d76 100644
--- a/tests/stdlib_test.cpp
+++ b/tests/stdlib_test.cpp
@@ -35,27 +35,34 @@
   EXPECT_DOUBLE_EQ(0.061637783047395089, drand48());
 }
 
-TEST(stdlib, lrand48_random_rand) {
+TEST(stdlib, lrand48) {
   srand48(0x01020304);
   EXPECT_EQ(1409163720, lrand48());
   EXPECT_EQ(397769746, lrand48());
   EXPECT_EQ(902267124, lrand48());
   EXPECT_EQ(132366131, lrand48());
+}
 
-#if defined(__BIONIC__)
-  // On bionic, random(3) is equivalent to lrand48...
+TEST(stdlib, random) {
   srandom(0x01020304);
-  EXPECT_EQ(1409163720, random());
-  EXPECT_EQ(397769746, random());
-  EXPECT_EQ(902267124, random());
-  EXPECT_EQ(132366131, random());
+  EXPECT_EQ(55436735, random());
+  EXPECT_EQ(1399865117, random());
+  EXPECT_EQ(2032643283, random());
+  EXPECT_EQ(571329216, random());
+}
 
-  // ...and rand(3) is the bottom 32 bits.
+TEST(stdlib, rand) {
   srand(0x01020304);
-  EXPECT_EQ(static_cast<int>(1409163720), rand());
-  EXPECT_EQ(static_cast<int>(397769746), rand());
-  EXPECT_EQ(static_cast<int>(902267124), rand());
-  EXPECT_EQ(static_cast<int>(132366131), rand());
+#if defined(__BIONIC__)
+  EXPECT_EQ(1675538669, rand());
+  EXPECT_EQ(1678228258, rand());
+  EXPECT_EQ(1352350131, rand());
+  EXPECT_EQ(824068976, rand());
+#else
+  EXPECT_EQ(55436735, rand());
+  EXPECT_EQ(1399865117, rand());
+  EXPECT_EQ(2032643283, rand());
+  EXPECT_EQ(571329216, rand());
 #endif
 }