diff --git a/drivers/char/random.c b/drivers/char/random.c
index b411182df6f6..0e03e9a05eff 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -358,79 +358,15 @@
 
 /* #define ADD_INTERRUPT_BENCH */
 
-/*
- * If the entropy count falls under this number of bits, then we
- * should wake up processes which are selecting or polling on write
- * access to /dev/random.
- */
-static int random_write_wakeup_bits = 28 * (1 << 5);
-
-/*
- * Originally, we used a primitive polynomial of degree .poolwords
- * over GF(2).  The taps for various sizes are defined below.  They
- * were chosen to be evenly spaced except for the last tap, which is 1
- * to get the twisting happening as fast as possible.
- *
- * For the purposes of better mixing, we use the CRC-32 polynomial as
- * well to make a (modified) twisted Generalized Feedback Shift
- * Register.  (See M. Matsumoto & Y. Kurita, 1992.  Twisted GFSR
- * generators.  ACM Transactions on Modeling and Computer Simulation
- * 2(3):179-194.  Also see M. Matsumoto & Y. Kurita, 1994.  Twisted
- * GFSR generators II.  ACM Transactions on Modeling and Computer
- * Simulation 4:254-266)
- *
- * Thanks to Colin Plumb for suggesting this.
- *
- * The mixing operation is much less sensitive than the output hash,
- * where we use BLAKE2s.  All that we want of mixing operation is that
- * it be a good non-cryptographic hash; i.e. it not produce collisions
- * when fed "random" data of the sort we expect to see.  As long as
- * the pool state differs for different inputs, we have preserved the
- * input entropy and done a good job.  The fact that an intelligent
- * attacker can construct inputs that will produce controlled
- * alterations to the pool's state is not important because we don't
- * consider such inputs to contribute any randomness.  The only
- * property we need with respect to them is that the attacker can't
- * increase his/her knowledge of the pool's state.  Since all
- * additions are reversible (knowing the final state and the input,
- * you can reconstruct the initial state), if an attacker has any
- * uncertainty about the initial state, he/she can only shuffle that
- * uncertainty about, but never cause any collisions (which would
- * decrease the uncertainty).
- *
- * Our mixing functions were analyzed by Lacharme, Roeck, Strubel, and
- * Videau in their paper, "The Linux Pseudorandom Number Generator
- * Revisited" (see: http://eprint.iacr.org/2012/251.pdf).  In their
- * paper, they point out that we are not using a true Twisted GFSR,
- * since Matsumoto & Kurita used a trinomial feedback polynomial (that
- * is, with only three taps, instead of the six that we are using).
- * As a result, the resulting polynomial is neither primitive nor
- * irreducible, and hence does not have a maximal period over
- * GF(2**32).  They suggest a slight change to the generator
- * polynomial which improves the resulting TGFSR polynomial to be
- * irreducible, which we have made here.
- */
 enum poolinfo {
-	POOL_WORDS = 128,
-	POOL_WORDMASK = POOL_WORDS - 1,
-	POOL_BYTES = POOL_WORDS * sizeof(u32),
-	POOL_BITS = POOL_BYTES * 8,
+	POOL_BITS = BLAKE2S_HASH_SIZE * 8,
 	POOL_BITSHIFT = ilog2(POOL_BITS),
 
 	/* To allow fractional bits to be tracked, the entropy_count field is
 	 * denominated in units of 1/8th bits. */
 	POOL_ENTROPY_SHIFT = 3,
 #define POOL_ENTROPY_BITS() (input_pool.entropy_count >> POOL_ENTROPY_SHIFT)
-	POOL_FRACBITS = POOL_BITS << POOL_ENTROPY_SHIFT,
-
-	/* x^128 + x^104 + x^76 + x^51 +x^25 + x + 1 */
-	POOL_TAP1 = 104,
-	POOL_TAP2 = 76,
-	POOL_TAP3 = 51,
-	POOL_TAP4 = 25,
-	POOL_TAP5 = 1,
-
-	EXTRACT_SIZE = BLAKE2S_HASH_SIZE / 2
+	POOL_FRACBITS = POOL_BITS << POOL_ENTROPY_SHIFT
 };
 
 /*
@@ -438,6 +374,12 @@ enum poolinfo {
  */
 static DECLARE_WAIT_QUEUE_HEAD(random_write_wait);
 static struct fasync_struct *fasync;
+/*
+ * If the entropy count falls under this number of bits, then we
+ * should wake up processes which are selecting or polling on write
+ * access to /dev/random.
+ */
+static int random_write_wakeup_bits = POOL_BITS * 3 / 4;
 
 static DEFINE_SPINLOCK(random_ready_list_lock);
 static LIST_HEAD(random_ready_list);
@@ -493,73 +435,31 @@ MODULE_PARM_DESC(ratelimit_disable, "Disable random ratelimit suppression");
  *
  **********************************************************************/
 
-static u32 input_pool_data[POOL_WORDS] __latent_entropy;
-
 static struct {
+	struct blake2s_state hash;
 	spinlock_t lock;
-	u16 add_ptr;
-	u16 input_rotate;
 	int entropy_count;
 } input_pool = {
+	.hash.h = { BLAKE2S_IV0 ^ (0x01010000 | BLAKE2S_HASH_SIZE),
+		    BLAKE2S_IV1, BLAKE2S_IV2, BLAKE2S_IV3, BLAKE2S_IV4,
+		    BLAKE2S_IV5, BLAKE2S_IV6, BLAKE2S_IV7 },
+	.hash.outlen = BLAKE2S_HASH_SIZE,
 	.lock = __SPIN_LOCK_UNLOCKED(input_pool.lock),
 };
 
-static ssize_t extract_entropy(void *buf, size_t nbytes, int min);
-static ssize_t _extract_entropy(void *buf, size_t nbytes);
+static bool extract_entropy(void *buf, size_t nbytes, int min);
+static void _extract_entropy(void *buf, size_t nbytes);
 
 static void crng_reseed(struct crng_state *crng, bool use_input_pool);
 
-static const u32 twist_table[8] = {
-	0x00000000, 0x3b6e20c8, 0x76dc4190, 0x4db26158,
-	0xedb88320, 0xd6d6a3e8, 0x9b64c2b0, 0xa00ae278 };
-
 /*
  * This function adds bytes into the entropy "pool".  It does not
  * update the entropy estimate.  The caller should call
  * credit_entropy_bits if this is appropriate.
- *
- * The pool is stirred with a primitive polynomial of the appropriate
- * degree, and then twisted.  We twist by three bits at a time because
- * it's cheap to do so and helps slightly in the expected case where
- * the entropy is concentrated in the low-order bits.
  */
 static void _mix_pool_bytes(const void *in, int nbytes)
 {
-	unsigned long i;
-	int input_rotate;
-	const u8 *bytes = in;
-	u32 w;
-
-	input_rotate = input_pool.input_rotate;
-	i = input_pool.add_ptr;
-
-	/* mix one byte at a time to simplify size handling and churn faster */
-	while (nbytes--) {
-		w = rol32(*bytes++, input_rotate);
-		i = (i - 1) & POOL_WORDMASK;
-
-		/* XOR in the various taps */
-		w ^= input_pool_data[i];
-		w ^= input_pool_data[(i + POOL_TAP1) & POOL_WORDMASK];
-		w ^= input_pool_data[(i + POOL_TAP2) & POOL_WORDMASK];
-		w ^= input_pool_data[(i + POOL_TAP3) & POOL_WORDMASK];
-		w ^= input_pool_data[(i + POOL_TAP4) & POOL_WORDMASK];
-		w ^= input_pool_data[(i + POOL_TAP5) & POOL_WORDMASK];
-
-		/* Mix the result back in with a twist */
-		input_pool_data[i] = (w >> 3) ^ twist_table[w & 7];
-
-		/*
-		 * Normally, we add 7 bits of rotation to the pool.
-		 * At the beginning of the pool, add an extra 7 bits
-		 * rotation, so that successive passes spread the
-		 * input bits across the pool evenly.
-		 */
-		input_rotate = (input_rotate + (i ? 7 : 14)) & 31;
-	}
-
-	input_pool.input_rotate = input_rotate;
-	input_pool.add_ptr = i;
+	blake2s_update(&input_pool.hash, in, nbytes);
 }
 
 static void __mix_pool_bytes(const void *in, int nbytes)
@@ -954,15 +854,14 @@ static int crng_slow_load(const u8 *cp, size_t len)
 static void crng_reseed(struct crng_state *crng, bool use_input_pool)
 {
 	unsigned long flags;
-	int i, num;
+	int i;
 	union {
 		u8 block[CHACHA_BLOCK_SIZE];
 		u32 key[8];
 	} buf;
 
 	if (use_input_pool) {
-		num = extract_entropy(&buf, 32, 16);
-		if (num == 0)
+		if (!extract_entropy(&buf, 32, 16))
 			return;
 	} else {
 		_extract_crng(&primary_crng, buf.block);
@@ -1329,74 +1228,48 @@ static size_t account(size_t nbytes, int min)
 }
 
 /*
- * This function does the actual extraction for extract_entropy.
- *
- * Note: we assume that .poolwords is a multiple of 16 words.
+ * This is an HKDF-like construction for using the hashed collected entropy
+ * as a PRF key, that's then expanded block-by-block.
  */
-static void extract_buf(u8 *out)
+static void _extract_entropy(void *buf, size_t nbytes)
 {
-	struct blake2s_state state __aligned(__alignof__(unsigned long));
-	u8 hash[BLAKE2S_HASH_SIZE];
-	unsigned long *salt;
 	unsigned long flags;
-
-	blake2s_init(&state, sizeof(hash));
-
-	/*
-	 * If we have an architectural hardware random number
-	 * generator, use it for BLAKE2's salt & personal fields.
-	 */
-	for (salt = (unsigned long *)&state.h[4];
-	     salt < (unsigned long *)&state.h[8]; ++salt) {
-		unsigned long v;
-		if (!arch_get_random_long(&v))
-			break;
-		*salt ^= v;
+	u8 seed[BLAKE2S_HASH_SIZE], next_key[BLAKE2S_HASH_SIZE];
+	struct {
+		unsigned long rdrand[32 / sizeof(long)];
+		size_t counter;
+	} block;
+	size_t i;
+
+	for (i = 0; i < ARRAY_SIZE(block.rdrand); ++i) {
+		if (!arch_get_random_long(&block.rdrand[i]))
+			block.rdrand[i] = random_get_entropy();
 	}
 
-	/* Generate a hash across the pool */
 	spin_lock_irqsave(&input_pool.lock, flags);
-	blake2s_update(&state, (const u8 *)input_pool_data, POOL_BYTES);
-	blake2s_final(&state, hash); /* final zeros out state */
 
-	/*
-	 * We mix the hash back into the pool to prevent backtracking
-	 * attacks (where the attacker knows the state of the pool
-	 * plus the current outputs, and attempts to find previous
-	 * outputs), unless the hash function can be inverted. By
-	 * mixing at least a hash worth of hash data back, we make
-	 * brute-forcing the feedback as hard as brute-forcing the
-	 * hash.
-	 */
-	__mix_pool_bytes(hash, sizeof(hash));
-	spin_unlock_irqrestore(&input_pool.lock, flags);
+	/* seed = HASHPRF(last_key, entropy_input) */
+	blake2s_final(&input_pool.hash, seed);
 
-	/* Note that EXTRACT_SIZE is half of hash size here, because above
-	 * we've dumped the full length back into mixer. By reducing the
-	 * amount that we emit, we retain a level of forward secrecy.
-	 */
-	memcpy(out, hash, EXTRACT_SIZE);
-	memzero_explicit(hash, sizeof(hash));
-}
+	/* next_key = HASHPRF(key, RDRAND || 0) */
+	block.counter = 0;
+	blake2s(next_key, (u8 *)&block, seed, sizeof(next_key), sizeof(block), sizeof(seed));
+	blake2s_init_key(&input_pool.hash, BLAKE2S_HASH_SIZE, next_key, sizeof(next_key));
 
-static ssize_t _extract_entropy(void *buf, size_t nbytes)
-{
-	ssize_t ret = 0, i;
-	u8 tmp[EXTRACT_SIZE];
+	spin_unlock_irqrestore(&input_pool.lock, flags);
+	memzero_explicit(next_key, sizeof(next_key));
 
 	while (nbytes) {
-		extract_buf(tmp);
-		i = min_t(int, nbytes, EXTRACT_SIZE);
-		memcpy(buf, tmp, i);
+		i = min_t(size_t, nbytes, BLAKE2S_HASH_SIZE);
+		/* output = HASHPRF(key, RDRAND || ++counter) */
+		++block.counter;
+		blake2s(buf, (u8 *)&block, seed, i, sizeof(block), sizeof(seed));
 		nbytes -= i;
 		buf += i;
-		ret += i;
 	}
 
-	/* Wipe data just returned from memory */
-	memzero_explicit(tmp, sizeof(tmp));
-
-	return ret;
+	memzero_explicit(seed, sizeof(seed));
+	memzero_explicit(&block, sizeof(block));
 }
 
 /*
@@ -1404,13 +1277,18 @@ static ssize_t _extract_entropy(void *buf, size_t nbytes)
  * returns it in a buffer.
  *
  * The min parameter specifies the minimum amount we can pull before
- * failing to avoid races that defeat catastrophic reseeding.
+ * failing to avoid races that defeat catastrophic reseeding. If we
+ * have less than min entropy available, we return false and buf is
+ * not filled.
  */
-static ssize_t extract_entropy(void *buf, size_t nbytes, int min)
+static bool extract_entropy(void *buf, size_t nbytes, int min)
 {
 	trace_extract_entropy(nbytes, POOL_ENTROPY_BITS(), _RET_IP_);
-	nbytes = account(nbytes, min);
-	return _extract_entropy(buf, nbytes);
+	if (account(nbytes, min)) {
+		_extract_entropy(buf, nbytes);
+		return true;
+	}
+	return false;
 }
 
 #define warn_unseeded_randomness(previous) \
@@ -1674,7 +1552,7 @@ static void __init init_std_data(void)
 	unsigned long rv;
 
 	mix_pool_bytes(&now, sizeof(now));
-	for (i = POOL_BYTES; i > 0; i -= sizeof(rv)) {
+	for (i = BLAKE2S_BLOCK_SIZE; i > 0; i -= sizeof(rv)) {
 		if (!arch_get_random_seed_long(&rv) &&
 		    !arch_get_random_long(&rv))
 			rv = random_get_entropy();
