Merge tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random

Pull random changes from Ted Ts'o:
 "Change /dev/random so that it uses the CRNG and only blocking if the
  CRNG hasn't initialized, instead of the old blocking pool. Also clean
  up archrandom.h, and some other miscellaneous cleanups"

* tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random: (24 commits)
  s390x: Mark archrandom.h functions __must_check
  powerpc: Mark archrandom.h functions __must_check
  powerpc: Use bool in archrandom.h
  x86: Mark archrandom.h functions __must_check
  linux/random.h: Mark CONFIG_ARCH_RANDOM functions __must_check
  linux/random.h: Use false with bool
  linux/random.h: Remove arch_has_random, arch_has_random_seed
  s390: Remove arch_has_random, arch_has_random_seed
  powerpc: Remove arch_has_random, arch_has_random_seed
  x86: Remove arch_has_random, arch_has_random_seed
  random: remove some dead code of poolinfo
  random: fix typo in add_timer_randomness()
  random: Add and use pr_fmt()
  random: convert to ENTROPY_BITS for better code readability
  random: remove unnecessary unlikely()
  random: remove kernel.random.read_wakeup_threshold
  random: delete code to pull data into pools
  random: remove the blocking pool
  random: make /dev/random be almost like /dev/urandom
  random: ignore GRND_RANDOM in getentropy(2)
  ...

1 files changed, 53 insertions, 263 deletions

diff --git a/drivers/char/random.c b/drivers/char/random.c
index cda12933a17d..c7f9584de2c8 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -307,6 +307,8 @@
  * Eastlake, Steve Crocker, and Jeff Schiller.
  */
 
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
 #include <linux/utsname.h>
 #include <linux/module.h>
 #include <linux/kernel.h>
@@ -354,7 +356,6 @@
 #define INPUT_POOL_WORDS	(1 << (INPUT_POOL_SHIFT-5))
 #define OUTPUT_POOL_SHIFT	10
 #define OUTPUT_POOL_WORDS	(1 << (OUTPUT_POOL_SHIFT-5))
-#define SEC_XFER_SIZE		512
 #define EXTRACT_SIZE		10
 
 
@@ -371,12 +372,6 @@
 #define ENTROPY_BITS(r) ((r)->entropy_count >> ENTROPY_SHIFT)
 
 /*
- * The minimum number of bits of entropy before we wake up a read on
- * /dev/random.  Should be enough to do a significant reseed.
- */
-static int random_read_wakeup_bits = 64;
-
-/*
  * 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.
@@ -436,42 +431,11 @@ static const struct poolinfo {
 	/* was: x^128 + x^103 + x^76 + x^51 +x^25 + x + 1 */
 	/* x^128 + x^104 + x^76 + x^51 +x^25 + x + 1 */
 	{ S(128),	104,	76,	51,	25,	1 },
-	/* was: x^32 + x^26 + x^20 + x^14 + x^7 + x + 1 */
-	/* x^32 + x^26 + x^19 + x^14 + x^7 + x + 1 */
-	{ S(32),	26,	19,	14,	7,	1 },
-#if 0
-	/* x^2048 + x^1638 + x^1231 + x^819 + x^411 + x + 1  -- 115 */
-	{ S(2048),	1638,	1231,	819,	411,	1 },
-
-	/* x^1024 + x^817 + x^615 + x^412 + x^204 + x + 1 -- 290 */
-	{ S(1024),	817,	615,	412,	204,	1 },
-
-	/* x^1024 + x^819 + x^616 + x^410 + x^207 + x^2 + 1 -- 115 */
-	{ S(1024),	819,	616,	410,	207,	2 },
-
-	/* x^512 + x^411 + x^308 + x^208 + x^104 + x + 1 -- 225 */
-	{ S(512),	411,	308,	208,	104,	1 },
-
-	/* x^512 + x^409 + x^307 + x^206 + x^102 + x^2 + 1 -- 95 */
-	{ S(512),	409,	307,	206,	102,	2 },
-	/* x^512 + x^409 + x^309 + x^205 + x^103 + x^2 + 1 -- 95 */
-	{ S(512),	409,	309,	205,	103,	2 },
-
-	/* x^256 + x^205 + x^155 + x^101 + x^52 + x + 1 -- 125 */
-	{ S(256),	205,	155,	101,	52,	1 },
-
-	/* x^128 + x^103 + x^78 + x^51 + x^27 + x^2 + 1 -- 70 */
-	{ S(128),	103,	78,	51,	27,	2 },
-
-	/* x^64 + x^52 + x^39 + x^26 + x^14 + x + 1 -- 15 */
-	{ S(64),	52,	39,	26,	14,	1 },
-#endif
 };
 
 /*
  * Static global variables
  */
-static DECLARE_WAIT_QUEUE_HEAD(random_read_wait);
 static DECLARE_WAIT_QUEUE_HEAD(random_write_wait);
 static struct fasync_struct *fasync;
 
@@ -530,11 +494,8 @@ struct entropy_store {
 	const struct poolinfo *poolinfo;
 	__u32 *pool;
 	const char *name;
-	struct entropy_store *pull;
-	struct work_struct push_work;
 
 	/* read-write data: */
-	unsigned long last_pulled;
 	spinlock_t lock;
 	unsigned short add_ptr;
 	unsigned short input_rotate;
@@ -550,9 +511,7 @@ static ssize_t _extract_entropy(struct entropy_store *r, void *buf,
 				size_t nbytes, int fips);
 
 static void crng_reseed(struct crng_state *crng, struct entropy_store *r);
-static void push_to_pool(struct work_struct *work);
 static __u32 input_pool_data[INPUT_POOL_WORDS] __latent_entropy;
-static __u32 blocking_pool_data[OUTPUT_POOL_WORDS] __latent_entropy;
 
 static struct entropy_store input_pool = {
 	.poolinfo = &poolinfo_table[0],
@@ -561,16 +520,6 @@ static struct entropy_store input_pool = {
 	.pool = input_pool_data
 };
 
-static struct entropy_store blocking_pool = {
-	.poolinfo = &poolinfo_table[1],
-	.name = "blocking",
-	.pull = &input_pool,
-	.lock = __SPIN_LOCK_UNLOCKED(blocking_pool.lock),
-	.pool = blocking_pool_data,
-	.push_work = __WORK_INITIALIZER(blocking_pool.push_work,
-					push_to_pool),
-};
-
 static __u32 const twist_table[8] = {
 	0x00000000, 0x3b6e20c8, 0x76dc4190, 0x4db26158,
 	0xedb88320, 0xd6d6a3e8, 0x9b64c2b0, 0xa00ae278 };
@@ -759,22 +708,17 @@ retry:
 		} while (unlikely(entropy_count < pool_size-2 && pnfrac));
 	}
 
-	if (unlikely(entropy_count < 0)) {
-		pr_warn("random: negative entropy/overflow: pool %s count %d\n",
+	if (WARN_ON(entropy_count < 0)) {
+		pr_warn("negative entropy/overflow: pool %s count %d\n",
 			r->name, entropy_count);
-		WARN_ON(1);
 		entropy_count = 0;
 	} else if (entropy_count > pool_size)
 		entropy_count = pool_size;
-	if ((r == &blocking_pool) && !r->initialized &&
-	    (entropy_count >> ENTROPY_SHIFT) > 128)
-		has_initialized = 1;
 	if (cmpxchg(&r->entropy_count, orig, entropy_count) != orig)
 		goto retry;
 
 	if (has_initialized) {
 		r->initialized = 1;
-		wake_up_interruptible(&random_read_wait);
 		kill_fasync(&fasync, SIGIO, POLL_IN);
 	}
 
@@ -783,36 +727,13 @@ retry:
 
 	if (r == &input_pool) {
 		int entropy_bits = entropy_count >> ENTROPY_SHIFT;
-		struct entropy_store *other = &blocking_pool;
 
 		if (crng_init < 2) {
 			if (entropy_bits < 128)
 				return;
 			crng_reseed(&primary_crng, r);
-			entropy_bits = r->entropy_count >> ENTROPY_SHIFT;
-		}
-
-		/* initialize the blocking pool if necessary */
-		if (entropy_bits >= random_read_wakeup_bits &&
-		    !other->initialized) {
-			schedule_work(&other->push_work);
-			return;
-		}
-
-		/* should we wake readers? */
-		if (entropy_bits >= random_read_wakeup_bits &&
-		    wq_has_sleeper(&random_read_wait)) {
-			wake_up_interruptible(&random_read_wait);
-			kill_fasync(&fasync, SIGIO, POLL_IN);
+			entropy_bits = ENTROPY_BITS(r);
 		}
-		/* If the input pool is getting full, and the blocking
-		 * pool has room, send some entropy to the blocking
-		 * pool.
-		 */
-		if (!work_pending(&other->push_work) &&
-		    (ENTROPY_BITS(r) > 6 * r->poolinfo->poolbytes) &&
-		    (ENTROPY_BITS(other) <= 6 * other->poolinfo->poolbytes))
-			schedule_work(&other->push_work);
 	}
 }
 
@@ -884,7 +805,7 @@ static void crng_initialize(struct crng_state *crng)
 		invalidate_batched_entropy();
 		numa_crng_init();
 		crng_init = 2;
-		pr_notice("random: crng done (trusting CPU's manufacturer)\n");
+		pr_notice("crng done (trusting CPU's manufacturer)\n");
 	}
 	crng->init_time = jiffies - CRNG_RESEED_INTERVAL - 1;
 }
@@ -946,8 +867,7 @@ static int crng_fast_load(const char *cp, size_t len)
 	if (crng_init_cnt >= CRNG_INIT_CNT_THRESH) {
 		invalidate_batched_entropy();
 		crng_init = 1;
-		wake_up_interruptible(&crng_init_wait);
-		pr_notice("random: fast init done\n");
+		pr_notice("fast init done\n");
 	}
 	return 1;
 }
@@ -1032,16 +952,15 @@ static void crng_reseed(struct crng_state *crng, struct entropy_store *r)
 		crng_init = 2;
 		process_random_ready_list();
 		wake_up_interruptible(&crng_init_wait);
-		pr_notice("random: crng init done\n");
+		kill_fasync(&fasync, SIGIO, POLL_IN);
+		pr_notice("crng init done\n");
 		if (unseeded_warning.missed) {
-			pr_notice("random: %d get_random_xx warning(s) missed "
-				  "due to ratelimiting\n",
+			pr_notice("%d get_random_xx warning(s) missed due to ratelimiting\n",
 				  unseeded_warning.missed);
 			unseeded_warning.missed = 0;
 		}
 		if (urandom_warning.missed) {
-			pr_notice("random: %d urandom warning(s) missed "
-				  "due to ratelimiting\n",
+			pr_notice("%d urandom warning(s) missed due to ratelimiting\n",
 				  urandom_warning.missed);
 			urandom_warning.missed = 0;
 		}
@@ -1246,7 +1165,7 @@ static void add_timer_randomness(struct timer_rand_state *state, unsigned num)
 	/*
 	 * delta is now minimum absolute delta.
 	 * Round down by 1 bit on general principles,
-	 * and limit entropy entimate to 12 bits.
+	 * and limit entropy estimate to 12 bits.
 	 */
 	credit_entropy_bits(r, min_t(int, fls(delta>>1), 11));
 }
@@ -1390,57 +1309,6 @@ EXPORT_SYMBOL_GPL(add_disk_randomness);
  *********************************************************************/
 
 /*
- * This utility inline function is responsible for transferring entropy
- * from the primary pool to the secondary extraction pool. We make
- * sure we pull enough for a 'catastrophic reseed'.
- */
-static void _xfer_secondary_pool(struct entropy_store *r, size_t nbytes);
-static void xfer_secondary_pool(struct entropy_store *r, size_t nbytes)
-{
-	if (!r->pull ||
-	    r->entropy_count >= (nbytes << (ENTROPY_SHIFT + 3)) ||
-	    r->entropy_count > r->poolinfo->poolfracbits)
-		return;
-
-	_xfer_secondary_pool(r, nbytes);
-}
-
-static void _xfer_secondary_pool(struct entropy_store *r, size_t nbytes)
-{
-	__u32	tmp[OUTPUT_POOL_WORDS];
-
-	int bytes = nbytes;
-
-	/* pull at least as much as a wakeup */
-	bytes = max_t(int, bytes, random_read_wakeup_bits / 8);
-	/* but never more than the buffer size */
-	bytes = min_t(int, bytes, sizeof(tmp));
-
-	trace_xfer_secondary_pool(r->name, bytes * 8, nbytes * 8,
-				  ENTROPY_BITS(r), ENTROPY_BITS(r->pull));
-	bytes = extract_entropy(r->pull, tmp, bytes,
-				random_read_wakeup_bits / 8, 0);
-	mix_pool_bytes(r, tmp, bytes);
-	credit_entropy_bits(r, bytes*8);
-}
-
-/*
- * Used as a workqueue function so that when the input pool is getting
- * full, we can "spill over" some entropy to the output pools.  That
- * way the output pools can store some of the excess entropy instead
- * of letting it go to waste.
- */
-static void push_to_pool(struct work_struct *work)
-{
-	struct entropy_store *r = container_of(work, struct entropy_store,
-					      push_work);
-	BUG_ON(!r);
-	_xfer_secondary_pool(r, random_read_wakeup_bits/8);
-	trace_push_to_pool(r->name, r->entropy_count >> ENTROPY_SHIFT,
-			   r->pull->entropy_count >> ENTROPY_SHIFT);
-}
-
-/*
  * This function decides how many bytes to actually take from the
  * given pool, and also debits the entropy count accordingly.
  */
@@ -1465,10 +1333,9 @@ retry:
 	if (ibytes < min)
 		ibytes = 0;
 
-	if (unlikely(entropy_count < 0)) {
-		pr_warn("random: negative entropy count: pool %s count %d\n",
+	if (WARN_ON(entropy_count < 0)) {
+		pr_warn("negative entropy count: pool %s count %d\n",
 			r->name, entropy_count);
-		WARN_ON(1);
 		entropy_count = 0;
 	}
 	nfrac = ibytes << (ENTROPY_SHIFT + 3);
@@ -1481,8 +1348,7 @@ retry:
 		goto retry;
 
 	trace_debit_entropy(r->name, 8 * ibytes);
-	if (ibytes &&
-	    (r->entropy_count >> ENTROPY_SHIFT) < random_write_wakeup_bits) {
+	if (ibytes && ENTROPY_BITS(r) < random_write_wakeup_bits) {
 		wake_up_interruptible(&random_write_wait);
 		kill_fasync(&fasync, SIGIO, POLL_OUT);
 	}
@@ -1603,7 +1469,6 @@ static ssize_t extract_entropy(struct entropy_store *r, void *buf,
 			spin_unlock_irqrestore(&r->lock, flags);
 			trace_extract_entropy(r->name, EXTRACT_SIZE,
 					      ENTROPY_BITS(r), _RET_IP_);
-			xfer_secondary_pool(r, EXTRACT_SIZE);
 			extract_buf(r, tmp);
 			spin_lock_irqsave(&r->lock, flags);
 			memcpy(r->last_data, tmp, EXTRACT_SIZE);
@@ -1612,60 +1477,11 @@ static ssize_t extract_entropy(struct entropy_store *r, void *buf,
 	}
 
 	trace_extract_entropy(r->name, nbytes, ENTROPY_BITS(r), _RET_IP_);
-	xfer_secondary_pool(r, nbytes);
 	nbytes = account(r, nbytes, min, reserved);
 
 	return _extract_entropy(r, buf, nbytes, fips_enabled);
 }
 
-/*
- * This function extracts randomness from the "entropy pool", and
- * returns it in a userspace buffer.
- */
-static ssize_t extract_entropy_user(struct entropy_store *r, void __user *buf,
-				    size_t nbytes)
-{
-	ssize_t ret = 0, i;
-	__u8 tmp[EXTRACT_SIZE];
-	int large_request = (nbytes > 256);
-
-	trace_extract_entropy_user(r->name, nbytes, ENTROPY_BITS(r), _RET_IP_);
-	if (!r->initialized && r->pull) {
-		xfer_secondary_pool(r, ENTROPY_BITS(r->pull)/8);
-		if (!r->initialized)
-			return 0;
-	}
-	xfer_secondary_pool(r, nbytes);
-	nbytes = account(r, nbytes, 0, 0);
-
-	while (nbytes) {
-		if (large_request && need_resched()) {
-			if (signal_pending(current)) {
-				if (ret == 0)
-					ret = -ERESTARTSYS;
-				break;
-			}
-			schedule();
-		}
-
-		extract_buf(r, tmp);
-		i = min_t(int, nbytes, EXTRACT_SIZE);
-		if (copy_to_user(buf, tmp, i)) {
-			ret = -EFAULT;
-			break;
-		}
-
-		nbytes -= i;
-		buf += i;
-		ret += i;
-	}
-
-	/* Wipe data just returned from memory */
-	memzero_explicit(tmp, sizeof(tmp));
-
-	return ret;
-}
-
 #define warn_unseeded_randomness(previous) \
 	_warn_unseeded_randomness(__func__, (void *) _RET_IP_, (previous))
 
@@ -1687,8 +1503,9 @@ static void _warn_unseeded_randomness(const char *func_name, void *caller,
 	print_once = true;
 #endif
 	if (__ratelimit(&unseeded_warning))
-		pr_notice("random: %s called from %pS with crng_init=%d\n",
-			  func_name, caller, crng_init);
+		printk_deferred(KERN_NOTICE "random: %s called from %pS "
+				"with crng_init=%d\n", func_name, caller,
+				crng_init);
 }
 
 /*
@@ -1931,7 +1748,6 @@ static void __init init_std_data(struct entropy_store *r)
 	ktime_t now = ktime_get_real();
 	unsigned long rv;
 
-	r->last_pulled = jiffies;
 	mix_pool_bytes(r, &now, sizeof(now));
 	for (i = r->poolinfo->poolbytes; i > 0; i -= sizeof(rv)) {
 		if (!arch_get_random_seed_long(&rv) &&
@@ -1955,7 +1771,6 @@ static void __init init_std_data(struct entropy_store *r)
 int __init rand_initialize(void)
 {
 	init_std_data(&input_pool);
-	init_std_data(&blocking_pool);
 	crng_initialize(&primary_crng);
 	crng_global_init_time = jiffies;
 	if (ratelimit_disable) {
@@ -1983,40 +1798,15 @@ void rand_initialize_disk(struct gendisk *disk)
 #endif
 
 static ssize_t
-_random_read(int nonblock, char __user *buf, size_t nbytes)
+urandom_read_nowarn(struct file *file, char __user *buf, size_t nbytes,
+		    loff_t *ppos)
 {
-	ssize_t n;
-
-	if (nbytes == 0)
-		return 0;
-
-	nbytes = min_t(size_t, nbytes, SEC_XFER_SIZE);
-	while (1) {
-		n = extract_entropy_user(&blocking_pool, buf, nbytes);
-		if (n < 0)
-			return n;
-		trace_random_read(n*8, (nbytes-n)*8,
-				  ENTROPY_BITS(&blocking_pool),
-				  ENTROPY_BITS(&input_pool));
-		if (n > 0)
-			return n;
-
-		/* Pool is (near) empty.  Maybe wait and retry. */
-		if (nonblock)
-			return -EAGAIN;
-
-		wait_event_interruptible(random_read_wait,
-		    blocking_pool.initialized &&
-		    (ENTROPY_BITS(&input_pool) >= random_read_wakeup_bits));
-		if (signal_pending(current))
-			return -ERESTARTSYS;
-	}
-}
+	int ret;
 
-static ssize_t
-random_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos)
-{
-	return _random_read(file->f_flags & O_NONBLOCK, buf, nbytes);
+	nbytes = min_t(size_t, nbytes, INT_MAX >> (ENTROPY_SHIFT + 3));
+	ret = extract_crng_user(buf, nbytes);
+	trace_urandom_read(8 * nbytes, 0, ENTROPY_BITS(&input_pool));
+	return ret;
 }
 
 static ssize_t
@@ -2024,22 +1814,29 @@ urandom_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos)
 {
 	unsigned long flags;
 	static int maxwarn = 10;
-	int ret;
 
 	if (!crng_ready() && maxwarn > 0) {
 		maxwarn--;
 		if (__ratelimit(&urandom_warning))
-			printk(KERN_NOTICE "random: %s: uninitialized "
-			       "urandom read (%zd bytes read)\n",
-			       current->comm, nbytes);
+			pr_notice("%s: uninitialized urandom read (%zd bytes read)\n",
+				  current->comm, nbytes);
 		spin_lock_irqsave(&primary_crng.lock, flags);
 		crng_init_cnt = 0;
 		spin_unlock_irqrestore(&primary_crng.lock, flags);
 	}
-	nbytes = min_t(size_t, nbytes, INT_MAX >> (ENTROPY_SHIFT + 3));
-	ret = extract_crng_user(buf, nbytes);
-	trace_urandom_read(8 * nbytes, 0, ENTROPY_BITS(&input_pool));
-	return ret;
+
+	return urandom_read_nowarn(file, buf, nbytes, ppos);
+}
+
+static ssize_t
+random_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos)
+{
+	int ret;
+
+	ret = wait_for_random_bytes();
+	if (ret != 0)
+		return ret;
+	return urandom_read_nowarn(file, buf, nbytes, ppos);
 }
 
 static __poll_t
@@ -2047,10 +1844,10 @@ random_poll(struct file *file, poll_table * wait)
 {
 	__poll_t mask;
 
-	poll_wait(file, &random_read_wait, wait);
+	poll_wait(file, &crng_init_wait, wait);
 	poll_wait(file, &random_write_wait, wait);
 	mask = 0;
-	if (ENTROPY_BITS(&input_pool) >= random_read_wakeup_bits)
+	if (crng_ready())
 		mask |= EPOLLIN | EPOLLRDNORM;
 	if (ENTROPY_BITS(&input_pool) < random_write_wakeup_bits)
 		mask |= EPOLLOUT | EPOLLWRNORM;
@@ -2141,7 +1938,6 @@ static long random_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
 		if (!capable(CAP_SYS_ADMIN))
 			return -EPERM;
 		input_pool.entropy_count = 0;
-		blocking_pool.entropy_count = 0;
 		return 0;
 	case RNDRESEEDCRNG:
 		if (!capable(CAP_SYS_ADMIN))
@@ -2185,23 +1981,27 @@ SYSCALL_DEFINE3(getrandom, char __user *, buf, size_t, count,
 {
 	int ret;
 
-	if (flags & ~(GRND_NONBLOCK|GRND_RANDOM))
+	if (flags & ~(GRND_NONBLOCK|GRND_RANDOM|GRND_INSECURE))
+		return -EINVAL;
+
+	/*
+	 * Requesting insecure and blocking randomness at the same time makes
+	 * no sense.
+	 */
+	if ((flags & (GRND_INSECURE|GRND_RANDOM)) == (GRND_INSECURE|GRND_RANDOM))
 		return -EINVAL;
 
 	if (count > INT_MAX)
 		count = INT_MAX;
 
-	if (flags & GRND_RANDOM)
-		return _random_read(flags & GRND_NONBLOCK, buf, count);
-
-	if (!crng_ready()) {
+	if (!(flags & GRND_INSECURE) && !crng_ready()) {
 		if (flags & GRND_NONBLOCK)
 			return -EAGAIN;
 		ret = wait_for_random_bytes();
 		if (unlikely(ret))
 			return ret;
 	}
-	return urandom_read(NULL, buf, count, NULL);
+	return urandom_read_nowarn(NULL, buf, count, NULL);
 }
 
 /********************************************************************
@@ -2214,8 +2014,7 @@ SYSCALL_DEFINE3(getrandom, char __user *, buf, size_t, count,
 
 #include <linux/sysctl.h>
 
-static int min_read_thresh = 8, min_write_thresh;
-static int max_read_thresh = OUTPUT_POOL_WORDS * 32;
+static int min_write_thresh;
 static int max_write_thresh = INPUT_POOL_WORDS * 32;
 static int random_min_urandom_seed = 60;
 static char sysctl_bootid[16];
@@ -2291,15 +2090,6 @@ struct ctl_table random_table[] = {
 		.data		= &input_pool.entropy_count,
 	},
 	{
-		.procname	= "read_wakeup_threshold",
-		.data		= &random_read_wakeup_bits,
-		.maxlen		= sizeof(int),
-		.mode		= 0644,
-		.proc_handler	= proc_dointvec_minmax,
-		.extra1		= &min_read_thresh,
-		.extra2		= &max_read_thresh,
-	},
-	{
 		.procname	= "write_wakeup_threshold",
 		.data		= &random_write_wakeup_bits,
 		.maxlen		= sizeof(int),