 @@ -1,1085 +1,1085 @@
-/*	$NetBSD: kern_rndq.c,v 1.7 2013/01/16 06:45:24 msaitoh Exp $	*/
+/*	$NetBSD: kern_rndq.c,v 1.8 2013/01/24 14:23:45 riastradh Exp $	*/
 /*-
  * Copyright (c) 1997-2011 The NetBSD Foundation, Inc.
  * All rights reserved.
+ *
  * This code is derived from software contributed to The NetBSD Foundation
  * by Michael Graff <explorer@flame.org> and Thor Lancelot Simon.
  * This code uses ideas and algorithms from the Linux driver written by
  * Ted Ts'o.
+ *
  * 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.
+ *
  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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>
-__KERNEL_RCSID(0, "$NetBSD: kern_rndq.c,v 1.7 2013/01/16 06:45:24 msaitoh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_rndq.c,v 1.8 2013/01/24 14:23:45 riastradh Exp $");
 #include <sys/param.h>
 #include <sys/ioctl.h>
 #include <sys/fcntl.h>
 #include <sys/select.h>
 #include <sys/poll.h>
 #include <sys/kmem.h>
 #include <sys/mutex.h>
 #include <sys/proc.h>
 #include <sys/kernel.h>
 #include <sys/conf.h>
 #include <sys/systm.h>
 #include <sys/callout.h>
 #include <sys/rnd.h>
 #include <sys/vnode.h>
 #include <sys/pool.h>
 #include <sys/kauth.h>
 #include <sys/once.h>
 #include <sys/rngtest.h>
 #include <sys/cpu.h>	/* XXX temporary, see rnd_detach_source */
 #include <dev/rnd_private.h>
 #if defined(__HAVE_CPU_COUNTER) && !defined(_RUMPKERNEL) /* XXX: bad pooka */
 #include <machine/cpu_counter.h>
 #endif
 #ifdef RND_DEBUG
 #define	DPRINTF(l,x)      if (rnd_debug & (l)) printf x
 int	rnd_debug = 0;
 #else
 #define	DPRINTF(l,x)
 #endif
 #define	RND_DEBUG_WRITE		0x0001
 #define	RND_DEBUG_READ		0x0002
 #define	RND_DEBUG_IOCTL		0x0004
 #define	RND_DEBUG_SNOOZE	0x0008
 /*
  * list devices attached
  */
 #if 0
 #define	RND_VERBOSE
 #endif
 /*
  * The size of a temporary buffer, kmem_alloc()ed when needed, and used for
  * reading and writing data.
  */
 #define	RND_TEMP_BUFFER_SIZE	128
 /*
  * This is a little bit of state information attached to each device that we
  * collect entropy from.  This is simply a collection buffer, and when it
  * is full it will be "detached" from the source and added to the entropy
  * pool after entropy is distilled as much as possible.
  */
 #define	RND_SAMPLE_COUNT	64	/* collect N samples, then compress */
 typedef struct _rnd_sample_t {
 	SIMPLEQ_ENTRY(_rnd_sample_t) next;
 	krndsource_t	*source;
 	int		cursor;
 	int		entropy;
 	u_int32_t	ts[RND_SAMPLE_COUNT];
 	u_int32_t	values[RND_SAMPLE_COUNT];
 } rnd_sample_t;
 /*
  * The event queue.  Fields are altered at an interrupt level.
  * All accesses must be protected with the mutex.
  */
 volatile int			rnd_timeout_pending;
 SIMPLEQ_HEAD(, _rnd_sample_t)	rnd_samples;
 kmutex_t			rnd_mtx;
 /*
  * Entropy sinks: usually other generators waiting to be rekeyed.
+ *
  * A sink's callback MUST NOT re-add the sink to the list, or
  * list corruption will occur.  The list is protected by the
  * rndsink_mtx, which must be released before calling any sink's
  * callback.
  */
 TAILQ_HEAD(, rndsink)		rnd_sinks;
 kmutex_t			rndsink_mtx;
 /*
  * Memory pool for sample buffers
  */
 static pool_cache_t rnd_mempc;
 /*
  * Our random pool.  This is defined here rather than using the general
  * purpose one defined in rndpool.c.
+ *
  * Samples are collected and queued into a separate mutex-protected queue
  * (rnd_samples, see above), and processed in a timeout routine; therefore,
  * the mutex protecting the random pool is at IPL_SOFTCLOCK() as well.
  */
 rndpool_t rnd_pool;
 kmutex_t  rndpool_mtx;
 kcondvar_t rndpool_cv;
 /*
  * This source is used to easily "remove" queue entries when the source
  * which actually generated the events is going away.
  */
 static krndsource_t rnd_source_no_collect = {
 	/* LIST_ENTRY list */
 	.name = { 'N', 'o', 'C', 'o', 'l', 'l', 'e', 'c', 't',
 , 0, 0, 0, 0, 0, 0 },
 	.last_time = 0, .last_delta = 0, .last_delta2 = 0, .total = 0,
 	.type = RND_TYPE_UNKNOWN,
 	.flags = (RND_FLAG_NO_COLLECT |
 		  RND_FLAG_NO_ESTIMATE |
 		  RND_TYPE_UNKNOWN),
 	.state = NULL,
 	.test_cnt = 0,
 	.test = NULL
 };
 struct callout rnd_callout, skew_callout;
 void	      rnd_wakeup_readers(void);
 static inline u_int32_t rnd_estimate_entropy(krndsource_t *, u_int32_t);
 static inline u_int32_t rnd_counter(void);
 static        void	rnd_timeout(void *);
 static	      void	rnd_process_events(void *);
 u_int32_t     rnd_extract_data_locked(void *, u_int32_t, u_int32_t); /* XXX */
 static	      void	rnd_add_data_ts(krndsource_t *, const void *const,
 					uint32_t, uint32_t, uint32_t);
 int			rnd_ready = 0;
 int			rnd_initial_entropy = 0;
 #ifdef DIAGNOSTIC
 static int		rnd_tested = 0;
 static rngtest_t	rnd_rt;
 static uint8_t		rnd_testbits[sizeof(rnd_rt.rt_b)];
 #endif
 LIST_HEAD(, krndsource)	rnd_sources;
 rndsave_t		*boot_rsp;
 /*
  * Generate a 32-bit counter.  This should be more machine dependent,
  * using cycle counters and the like when possible.
  */
 static inline u_int32_t
 rnd_counter(void)
+{
 	struct timeval tv;
 #if defined(__HAVE_CPU_COUNTER) && !defined(_RUMPKERNEL) /* XXX: bad pooka */
 	if (cpu_hascounter())
 		return (cpu_counter32());
 #endif
 	if (rnd_ready) {
 		microtime(&tv);
 		return (tv.tv_sec * 1000000 + tv.tv_usec);
+	}
 	/* when called from rnd_init, its too early to call microtime safely */
 	return (0);
+}
 /*
  * Check to see if there are readers waiting on us.  If so, kick them.
  */
 void
 rnd_wakeup_readers(void)
+{
 	rndsink_t *sink, *tsink;
 	TAILQ_HEAD(, rndsink) sunk = TAILQ_HEAD_INITIALIZER(sunk);
 	mutex_spin_enter(&rndpool_mtx);
 	if (rndpool_get_entropy_count(&rnd_pool) < RND_ENTROPY_THRESHOLD * 8) {
 		mutex_spin_exit(&rndpool_mtx);
 		return;
+	}
 	/*
 	 * First, take care of in-kernel consumers needing rekeying.
 	 */
 	mutex_spin_enter(&rndsink_mtx);
 	TAILQ_FOREACH_SAFE(sink, &rnd_sinks, tailq, tsink) {
 		if (!mutex_tryenter(&sink->mtx)) {
 #ifdef RND_VERBOSE
 			printf("rnd_wakeup_readers: "
 			       "skipping busy rndsink\n");
 #endif
 			continue;
+		}
 		KASSERT(RSTATE_PENDING == sink->state);
 		if ((sink->len + RND_ENTROPY_THRESHOLD) * 8 <
 			rndpool_get_entropy_count(&rnd_pool)) {
 			/* We have enough entropy to sink some here. */
 			if (rndpool_extract_data(&rnd_pool, sink->data,
 						 sink->len, RND_EXTRACT_GOOD)
 			    != sink->len) {
 				panic("could not extract estimated "
 				      "entropy from pool");
+			}
 			sink->state = RSTATE_HASBITS;
 			/* Move this sink to the list of pending callbacks */
 			TAILQ_REMOVE(&rnd_sinks, sink, tailq);
 			TAILQ_INSERT_HEAD(&sunk, sink, tailq);
 		} else {
 			mutex_exit(&sink->mtx);
+		}
+	}
 	mutex_spin_exit(&rndsink_mtx);
 	/*
 	 * If we still have enough new bits to do something, feed userspace.
 	 */
 	if (rndpool_get_entropy_count(&rnd_pool) > RND_ENTROPY_THRESHOLD * 8) {
 #ifdef RND_VERBOSE
 		if (!rnd_initial_entropy)
 			printf("rnd: have initial entropy (%u)\n",
 			       rndpool_get_entropy_count(&rnd_pool));
 #endif
 		rnd_initial_entropy = 1;
 		mutex_spin_exit(&rndpool_mtx);
 	} else {
 		mutex_spin_exit(&rndpool_mtx);
+	}
 	/*
 	 * Now that we have dropped the mutex, we can run sinks' callbacks.
 	 * Since we have reused the "tailq" member of the sink structure for
 	 * this temporary on-stack queue, the callback must NEVER re-add
 	 * the sink to the main queue, or our on-stack queue will become
 	 * corrupt.
 	 */
 	while ((sink = TAILQ_FIRST(&sunk))) {
 #ifdef RND_VERBOSE
 		printf("supplying %d bytes to entropy sink \"%s\""
 		       " (cb %p, arg %p).\n",
 		       (int)sink->len, sink->name, sink->cb, sink->arg);
 #endif
 		sink->state = RSTATE_HASBITS;
 		sink->cb(sink->arg);
 		TAILQ_REMOVE(&sunk, sink, tailq);
 		mutex_spin_exit(&sink->mtx);
+	}
+}
 /*
  * Use the timing of the event to estimate the entropy gathered.
  * If all the differentials (first, second, and third) are non-zero, return
  * non-zero.  If any of these are zero, return zero.
  */
 static inline u_int32_t
 rnd_estimate_entropy(krndsource_t *rs, u_int32_t t)
+{
 	int32_t delta, delta2, delta3;
 	/*
 	 * If the time counter has overflowed, calculate the real difference.
 	 * If it has not, it is simplier.
 	 */
 	if (t < rs->last_time)
 		delta = UINT_MAX - rs->last_time + t;
 	else
 		delta = rs->last_time - t;
 	if (delta < 0)
 		delta = -delta;
 	/*
 	 * Calculate the second and third order differentials
 	 */
 	delta2 = rs->last_delta - delta;
 	if (delta2 < 0)
 		delta2 = -delta2;
 	delta3 = rs->last_delta2 - delta2;
 	if (delta3 < 0)
 		delta3 = -delta3;
 	rs->last_time = t;
 	rs->last_delta = delta;
 	rs->last_delta2 = delta2;
 	/*
 	 * If any delta is 0, we got no entropy.  If all are non-zero, we
 	 * might have something.
 	 */
 	if (delta == 0 || delta2 == 0 || delta3 == 0)
 		return (0);
 	return (1);
+}
 #if defined(__HAVE_CPU_COUNTER) && !defined(_RUMPKERNEL)
 static void
 rnd_skew(void *arg)
+{
 	static krndsource_t skewsrc;
 	static int live, flipflop;
 	/*
 	 * Only one instance of this callout will ever be scheduled
 	 * at a time (it is only ever scheduled by itself).  So no
 	 * locking is required here.
 	 */
 	/*
 	 * Even on systems with seemingly stable clocks, the
 	 * entropy estimator seems to think we get 1 bit here
 	 * about every 2 calls.  That seems like too much.  Set
 	 * NO_ESTIMATE on this source until we can better analyze
 	 * the entropy of its output.
 	 */
 	if (__predict_false(!live)) {
 		rnd_attach_source(&skewsrc, "callout", RND_TYPE_SKEW,
 				  RND_FLAG_NO_ESTIMATE);
 		live = 1;
+	}
 	flipflop = !flipflop;
 	if (flipflop) {
 		rnd_add_uint32(&skewsrc, rnd_counter());
 		callout_schedule(&skew_callout, hz);
 	} else {
 		callout_schedule(&skew_callout, 1);
+	}
+}
 #endif
 /*
  * initialize the global random pool for our use.
  * rnd_init() must be called very early on in the boot process, so
  * the pool is ready for other devices to attach as sources.
  */
 void
 rnd_init(void)
+{
 	u_int32_t c;
 	if (rnd_ready)
 		return;
 	mutex_init(&rnd_mtx, MUTEX_DEFAULT, IPL_VM);
 	mutex_init(&rndsink_mtx, MUTEX_DEFAULT, IPL_VM);
 	callout_init(&rnd_callout, CALLOUT_MPSAFE);
 	callout_setfunc(&rnd_callout, rnd_timeout, NULL);
 	/*
 	 * take a counter early, hoping that there's some variance in
 	 * the following operations
 	 */
 	c = rnd_counter();
 	LIST_INIT(&rnd_sources);
 	SIMPLEQ_INIT(&rnd_samples);
 	TAILQ_INIT(&rnd_sinks);
 	rndpool_init(&rnd_pool);
 	mutex_init(&rndpool_mtx, MUTEX_DEFAULT, IPL_VM);
 	cv_init(&rndpool_cv, "rndread");
 	rnd_mempc = pool_cache_init(sizeof(rnd_sample_t), 0, 0, 0,
 				    "rndsample", NULL, IPL_VM,
 				    NULL, NULL, NULL);
 	/*
 	 * Set resource limit. The rnd_process_events() function
 	 * is called every tick and process the sample queue.
 	 * Without limitation, if a lot of rnd_add_*() are called,
 	 * all kernel memory may be eaten up.
 	 */
 	pool_cache_sethardlimit(rnd_mempc, RND_POOLBITS, NULL, 0);
 	/*
 	 * Mix *something*, *anything* into the pool to help it get started.
 	 * However, it's not safe for rnd_counter() to call microtime() yet,
 	 * so on some platforms we might just end up with zeros anyway.
 	 * XXX more things to add would be nice.
 	 */
 	if (c) {
 		mutex_spin_enter(&rndpool_mtx);
 		rndpool_add_data(&rnd_pool, &c, sizeof(c), 1);
 		c = rnd_counter();
 		rndpool_add_data(&rnd_pool, &c, sizeof(c), 1);
 		mutex_spin_exit(&rndpool_mtx);
+	}
 	rnd_ready = 1;
 	/*
 	 * If we have a cycle counter, take its error with respect
 	 * to the callout mechanism as a source of entropy, ala
 	 * TrueRand.
+ 	 *
 	 * XXX This will do little when the cycle counter *is* what's
 	 * XXX clocking the callout mechanism.  How to get this right
 	 * XXX without unsightly spelunking in the timecounter code?
 	 */
 #if defined(__HAVE_CPU_COUNTER) && !defined(_RUMPKERNEL) /* XXX: bad pooka */
 	callout_init(&skew_callout, CALLOUT_MPSAFE);
 	callout_setfunc(&skew_callout, rnd_skew, NULL);
 	rnd_skew(NULL);
 #endif
 #ifdef RND_VERBOSE
 	printf("rnd: initialised (%u)%s", RND_POOLBITS,
 	       c ? " with counter\n" : "\n");
 #endif
 	if (boot_rsp != NULL) {
 		mutex_spin_enter(&rndpool_mtx);
 			rndpool_add_data(&rnd_pool, boot_rsp->data,
 					 sizeof(boot_rsp->data),
 					 MIN(boot_rsp->entropy,
 					     RND_POOLBITS / 2));
 		if (rndpool_get_entropy_count(&rnd_pool) >
 		    RND_ENTROPY_THRESHOLD * 8) {
                 	rnd_initial_entropy = 1;
+		}
                 mutex_spin_exit(&rndpool_mtx);
 #ifdef RND_VERBOSE
 		printf("rnd: seeded with %d bits\n",
 		       MIN(boot_rsp->entropy, RND_POOLBITS / 2));
 #endif
 		memset(boot_rsp, 0, sizeof(*boot_rsp));
+	}
+}
 static rnd_sample_t *
 rnd_sample_allocate(krndsource_t *source)
+{
 	rnd_sample_t *c;
 	c = pool_cache_get(rnd_mempc, PR_WAITOK);
 	if (c == NULL)
 		return (NULL);
 	c->source = source;
 	c->cursor = 0;
 	c->entropy = 0;
 	return (c);
+}
 /*
  * Don't wait on allocation.  To be used in an interrupt context.
  */
 static rnd_sample_t *
 rnd_sample_allocate_isr(krndsource_t *source)
+{
 	rnd_sample_t *c;
 	c = pool_cache_get(rnd_mempc, PR_NOWAIT);
 	if (c == NULL)
 		return (NULL);
 	c->source = source;
 	c->cursor = 0;
 	c->entropy = 0;
 	return (c);
+}
 static void
 rnd_sample_free(rnd_sample_t *c)
+{
 	memset(c, 0, sizeof(*c));
 	pool_cache_put(rnd_mempc, c);
+}
 /*
  * Add a source to our list of sources.
  */
 void
 rnd_attach_source(krndsource_t *rs, const char *name, u_int32_t type,
     u_int32_t flags)
+{
 	u_int32_t ts;
 	ts = rnd_counter();
 	strlcpy(rs->name, name, sizeof(rs->name));
 	rs->last_time = ts;
 	rs->last_delta = 0;
 	rs->last_delta2 = 0;
 	rs->total = 0;
 	/*
 	 * Force network devices to not collect any entropy by
 	 * default.
 	 */
 	if (type == RND_TYPE_NET)
 		flags |= (RND_FLAG_NO_COLLECT | RND_FLAG_NO_ESTIMATE);
 	/*
  	 * Hardware RNGs get extra space for statistical testing.
 	 */
 	if (type == RND_TYPE_RNG) {
 		rs->test = kmem_alloc(sizeof(rngtest_t), KM_NOSLEEP);
 		rs->test_cnt = 0;
 	} else {
 		rs->test = NULL;
 		rs->test_cnt = -1;
+	}
 	rs->type = type;
 	rs->flags = flags;
 	rs->state = rnd_sample_allocate(rs);
 	mutex_spin_enter(&rndpool_mtx);
 	LIST_INSERT_HEAD(&rnd_sources, rs, list);
 #ifdef RND_VERBOSE
 	printf("rnd: %s attached as an entropy source (", rs->name);
 	if (!(flags & RND_FLAG_NO_COLLECT)) {
 		printf("collecting");
 		if (flags & RND_FLAG_NO_ESTIMATE)
 			printf(" without estimation");
+	}
 	else
 		printf("off");
 	printf(")\n");
 #endif
 	/*
 	 * Again, put some more initial junk in the pool.
 	 * XXX Bogus, but harder to guess than zeros.
 	 */
 	rndpool_add_data(&rnd_pool, &ts, sizeof(u_int32_t), 1);
 	mutex_spin_exit(&rndpool_mtx);
+}
 /*
  * Remove a source from our list of sources.
  */
 void
 rnd_detach_source(krndsource_t *source)
+{
 	rnd_sample_t *sample;
 	mutex_spin_enter(&rnd_mtx);
 	LIST_REMOVE(source, list);
 	/*
 	 * If there are samples queued up "remove" them from the sample queue
 	 * by setting the source to the no-collect pseudosource.
 	 */
 	sample = SIMPLEQ_FIRST(&rnd_samples);
 	while (sample != NULL) {
 		if (sample->source == source)
 			sample->source = &rnd_source_no_collect;
 		sample = SIMPLEQ_NEXT(sample, next);
+	}
 	mutex_spin_exit(&rnd_mtx);
 	if (!cpu_softintr_p()) {	/* XXX XXX very temporary "fix" */
 		if (source->state) {
 			rnd_sample_free(source->state);
 			source->state = NULL;
+		}
 		if (source->test) {
 			kmem_free(source->test, sizeof(rngtest_t));
+		}
+	}
 #ifdef RND_VERBOSE
 	printf("rnd: %s detached as an entropy source\n", source->name);
 #endif
+}
 /*
  * Add a 32-bit value to the entropy pool.  The rs parameter should point to
  * the source-specific source structure.
  */
 void
 _rnd_add_uint32(krndsource_t *rs, u_int32_t val)
+{
 	u_int32_t ts;
 	u_int32_t entropy = 0;
 	if (rs->flags & RND_FLAG_NO_COLLECT)
 		return;
 	/*
 	 * Sample the counter as soon as possible to avoid
 	 * entropy overestimation.
 	 */
 	ts = rnd_counter();
 	/*
 	 * If we are estimating entropy on this source,
 	 * calculate differentials.
 	 */
 	if ((rs->flags & RND_FLAG_NO_ESTIMATE) == 0) {
 		entropy = rnd_estimate_entropy(rs, ts);
+	}
 	rnd_add_data_ts(rs, &val, sizeof(val), entropy, ts);
+}
 void
 rnd_add_data(krndsource_t *rs, const void *const data, uint32_t len,
 	     uint32_t entropy)
+{
 	/*
 	 * This interface is meant for feeding data which is,
 	 * itself, random.  Don't estimate entropy based on
 	 * timestamp, just directly add the data.
 	 */
 	rnd_add_data_ts(rs, data, len, entropy, rnd_counter());
+}
 static void
 rnd_add_data_ts(krndsource_t *rs, const void *const data, u_int32_t len,
 		u_int32_t entropy, uint32_t ts)
+{
 	rnd_sample_t *state = NULL;
 	const uint32_t *dint = data;
 	int todo, done, filled = 0;
 	SIMPLEQ_HEAD(, _rnd_sample_t) tmp_samples =
 	    		SIMPLEQ_HEAD_INITIALIZER(tmp_samples);
 	if (rs->flags & RND_FLAG_NO_COLLECT) {
 		return;
+	}
 	/*
 	 * Loop over data packaging it into sample buffers.
 	 * If a sample buffer allocation fails, drop all data.
 	 */
 	todo = len / sizeof(*dint);
 	for (done = 0; done < todo ; done++) {
 		state = rs->state;
 		if (state == NULL) {
 			state = rnd_sample_allocate_isr(rs);
 			if (__predict_false(state == NULL)) {
 				break;
+			}
 			rs->state = state;
+		}
 		state->ts[state->cursor] = ts;
 		state->values[state->cursor] = dint[done];
 		state->cursor++;
 		if (state->cursor == RND_SAMPLE_COUNT) {
 			SIMPLEQ_INSERT_HEAD(&tmp_samples, state, next);
 			filled++;
 			rs->state = NULL;
+		}
+	}
 	if (__predict_false(state == NULL)) {
 		while ((state = SIMPLEQ_FIRST(&tmp_samples))) {
 			SIMPLEQ_REMOVE_HEAD(&tmp_samples, next);
 			rnd_sample_free(state);
+		}
 		return;
+	}
 	/*
 	 * Claim all the entropy on the last one we send to
 	 * the pool, so we don't rely on it being evenly distributed
 	 * in the supplied data.
+	 *
 	 * XXX The rndpool code must accept samples with more
 	 * XXX claimed entropy than bits for this to work right.
 	 */
 	state->entropy += entropy;
 	rs->total += entropy;
 	/*
 	 * If we didn't finish any sample buffers, we're done.
 	 */
 	if (!filled) {
 		return;
+	}
 	mutex_spin_enter(&rnd_mtx);
 	while ((state = SIMPLEQ_FIRST(&tmp_samples))) {
 		SIMPLEQ_REMOVE_HEAD(&tmp_samples, next);
 		SIMPLEQ_INSERT_HEAD(&rnd_samples, state, next);
+	}
 	/*
 	 * If we are still starting up, cause immediate processing of
 	 * the queued samples.  Otherwise, if the timeout isn't
 	 * pending, have it run in the near future.
 	 */
 	if (__predict_false(cold)) {
 #ifdef RND_VERBOSE
 		printf("rnd: directly processing boot-time events.\n");
 #endif
 		rnd_process_events(NULL);	/* Drops lock! */
 		return;
+	}
 	if (rnd_timeout_pending == 0) {
 		rnd_timeout_pending = 1;
 		mutex_spin_exit(&rnd_mtx);
 		callout_schedule(&rnd_callout, 1);
 		return;
+	}
 	mutex_spin_exit(&rnd_mtx);
+}
 static int
 rnd_hwrng_test(rnd_sample_t *sample)
+{
 	krndsource_t *source = sample->source;
 	size_t cmplen;
 	uint8_t *v1, *v2;
 	size_t resid, totest;
-	KASSERT(source->type = RND_TYPE_RNG);
+	KASSERT(source->type == RND_TYPE_RNG);
 	/*
 	 * Continuous-output test: compare two halves of the
 	 * sample buffer to each other.  The sample buffer (64 ints,
 	 * so either 256 or 512 bytes on any modern machine) should be
 	 * much larger than a typical hardware RNG output, so this seems
 	 * a reasonable way to do it without retaining extra data.
 	 */
 	cmplen = sizeof(sample->values) / 2;
 	v1 = (uint8_t *)sample->values;
 	v2 = (uint8_t *)sample->values + cmplen;
 	if (__predict_false(!memcmp(v1, v2, cmplen))) {
 		printf("rnd: source \"%s\" failed continuous-output test.\n",
 		       source->name);
 		return 1;
+	}
 	/*
 	 * FIPS 140 statistical RNG test.  We must accumulate 20,000 bits.
 	 */
 	if (__predict_true(source->test_cnt == -1)) {
 		/* already passed the test */
 		return 0;
+	}
 	resid = FIPS140_RNG_TEST_BYTES - source->test_cnt;
 	totest = MIN(RND_SAMPLE_COUNT * 4, resid);
 	memcpy(source->test->rt_b + source->test_cnt, sample->values, totest);
 	resid -= totest;
 	source->test_cnt += totest;
 	if (resid == 0) {
 		strlcpy(source->test->rt_name, source->name,
 			sizeof(source->test->rt_name));
 		if (rngtest(source->test)) {
 			printf("rnd: source \"%s\" failed statistical test.",
 			       source->name);
 			return 1;
+		}
 		source->test_cnt = -1;
 		memset(source->test, 0, sizeof(*source->test));
+	}
 	return 0;
+}
 /*
  * Process the events in the ring buffer.  Called by rnd_timeout or
  * by the add routines directly if the callout has never fired (that
  * is, if we are "cold" -- just booted).
+ *
  * Call with rnd_mtx held -- WILL RELEASE IT.
  */
 static void
 rnd_process_events(void *arg)
+{
 	rnd_sample_t *sample;
 	krndsource_t *source, *badsource = NULL;
 	u_int32_t entropy;
 	SIMPLEQ_HEAD(, _rnd_sample_t) dq_samples =
 			SIMPLEQ_HEAD_INITIALIZER(dq_samples);
 	SIMPLEQ_HEAD(, _rnd_sample_t) df_samples =
 			SIMPLEQ_HEAD_INITIALIZER(df_samples);
         TAILQ_HEAD(, rndsink) sunk = TAILQ_HEAD_INITIALIZER(sunk);
 	/*
 	 * Sample queue is protected by rnd_mtx, drain to onstack queue
 	 * and drop lock.
 	 */
 	while ((sample = SIMPLEQ_FIRST(&rnd_samples))) {
 		SIMPLEQ_REMOVE_HEAD(&rnd_samples, next);
 		/*
 		 * We repeat this check here, since it is possible
 		 * the source was disabled before we were called, but
 		 * after the entry was queued.
 		 */
 		if (__predict_false(sample->source->flags
 				    & RND_FLAG_NO_COLLECT)) {
 			SIMPLEQ_INSERT_TAIL(&df_samples, sample, next);
 		} else {
 			SIMPLEQ_INSERT_TAIL(&dq_samples, sample, next);
+		}
+	}
 	mutex_spin_exit(&rnd_mtx);
 	/* Don't thrash the rndpool mtx either.  Hold, add all samples. */
 	mutex_spin_enter(&rndpool_mtx);
 	while ((sample = SIMPLEQ_FIRST(&dq_samples))) {
 		SIMPLEQ_REMOVE_HEAD(&dq_samples, next);
 		source = sample->source;
 		entropy = sample->entropy;
 		/*
 		 * Hardware generators are great but sometimes they
 		 * have...hardware issues.  Don't use any data from
 		 * them unless it passes some tests.
 		 */
 		if (source->type == RND_TYPE_RNG) {
 			if (__predict_false(rnd_hwrng_test(sample))) {
 				/*
 				 * Detach the bad source.  See below.
 				 */
 				badsource = source;
 				printf("rnd: detaching source \"%s\".",
 				       badsource->name);
 				break;
+			}
+		}
 		rndpool_add_data(&rnd_pool, sample->values,
 		    RND_SAMPLE_COUNT * 4, 0);
 		rndpool_add_data(&rnd_pool, sample->ts,
 		    RND_SAMPLE_COUNT * 4, entropy);
 		source->total += sample->entropy;
 		SIMPLEQ_INSERT_TAIL(&df_samples, sample, next);
+	}
 	mutex_spin_exit(&rndpool_mtx);
 	/* Now we hold no locks: clean up. */
 	if (__predict_false(badsource)) {
 		/*
 		 * The detach routine frees any samples we have not
 		 * dequeued ourselves.  For sanity's sake, we simply
 		 * free (without using) all dequeued samples from the
 		 * point at which we detected a problem onwards.
 		 */
 		rnd_detach_source(badsource);
 		while ((sample = SIMPLEQ_FIRST(&dq_samples))) {
 			SIMPLEQ_REMOVE_HEAD(&dq_samples, next);
 			rnd_sample_free(sample);
+		}
+	}
 	while ((sample = SIMPLEQ_FIRST(&df_samples))) {
 		SIMPLEQ_REMOVE_HEAD(&df_samples, next);
 		rnd_sample_free(sample);
+	}
 	/*
 	 * Wake up any potential readers waiting.
 	 */
 	rnd_wakeup_readers();
+}
 /*
  * Timeout, run to process the events in the ring buffer.
  */
 static void
 rnd_timeout(void *arg)
+{
         mutex_spin_enter(&rnd_mtx);
         rnd_timeout_pending = 0;
         rnd_process_events(arg);
+}
 u_int32_t
 rnd_extract_data_locked(void *p, u_int32_t len, u_int32_t flags)
+{
 	static int timed_in;
 	KASSERT(mutex_owned(&rndpool_mtx));
 	if (__predict_false(!timed_in)) {
 		if (boottime.tv_sec) {
 			rndpool_add_data(&rnd_pool, &boottime,
 					 sizeof(boottime), 0);
+		}
 		timed_in++;
+	}
 	if (__predict_false(!rnd_initial_entropy)) {
 		u_int32_t c;
 #ifdef RND_VERBOSE
 		printf("rnd: WARNING! initial entropy low (%u).\n",
 		       rndpool_get_entropy_count(&rnd_pool));
 #endif
 		/* Try once again to put something in the pool */
 		c = rnd_counter();
 		rndpool_add_data(&rnd_pool, &c, sizeof(u_int32_t), 1);
+	}
 #ifdef DIAGNOSTIC
 	while (!rnd_tested) {
 		int entropy_count;
 		entropy_count = rndpool_get_entropy_count(&rnd_pool);
 #ifdef RND_VERBOSE
 		printf("rnd: starting statistical RNG test, entropy = %d.\n",
 			entropy_count);
 #endif
 		if (rndpool_extract_data(&rnd_pool, rnd_rt.rt_b,
 		    sizeof(rnd_rt.rt_b), RND_EXTRACT_ANY)
 		    != sizeof(rnd_rt.rt_b)) {
 			panic("rnd: could not get bits for statistical test");
+		}
 		/*
 		 * Stash the tested bits so we can put them back in the
 		 * pool, restoring the entropy count.  DO NOT rely on
 		 * rngtest to maintain the bits pristine -- we could end
 		 * up adding back non-random data claiming it were pure
 		 * entropy.
 		 */
 		memcpy(rnd_testbits, rnd_rt.rt_b, sizeof(rnd_rt.rt_b));
 		strlcpy(rnd_rt.rt_name, "entropy pool", sizeof(rnd_rt.rt_name));
 		if (rngtest(&rnd_rt)) {
 			/*
 			 * The probabiliity of a Type I error is 3/10000,
 			 * but note this can only happen at boot time.
 			 * The relevant standard says to reset the module,
 			 * but developers objected...
 			 */
 			printf("rnd: WARNING, ENTROPY POOL FAILED "
 			       "STATISTICAL TEST!\n");
 			continue;
+		}
 		memset(&rnd_rt, 0, sizeof(rnd_rt));
 		rndpool_add_data(&rnd_pool, rnd_testbits, sizeof(rnd_testbits),
 				 entropy_count);
 		memset(rnd_testbits, 0, sizeof(rnd_testbits));
 #ifdef RND_VERBOSE
 		printf("rnd: statistical RNG test done, entropy = %d.\n",
 		       rndpool_get_entropy_count(&rnd_pool));
 #endif
 		rnd_tested++;
+	}
 #endif
 	return rndpool_extract_data(&rnd_pool, p, len, flags);
+}
 u_int32_t
 rnd_extract_data(void *p, u_int32_t len, u_int32_t flags)
+{
 	uint32_t retval;
 	mutex_spin_enter(&rndpool_mtx);
 	retval = rnd_extract_data_locked(p, len, flags);
 	mutex_spin_exit(&rndpool_mtx);
 	return retval;
+}
 void
 rndsink_attach(rndsink_t *rs)
+{
 #ifdef RND_VERBOSE
 	printf("rnd: entropy sink \"%s\" wants %d bytes of data.\n",
 	       rs->name, (int)rs->len);
 #endif
 	KASSERT(mutex_owned(&rs->mtx));
 	KASSERT(rs->state = RSTATE_PENDING);
 	mutex_spin_enter(&rndsink_mtx);
 	TAILQ_INSERT_TAIL(&rnd_sinks, rs, tailq);
 	mutex_spin_exit(&rndsink_mtx);
 	mutex_spin_enter(&rnd_mtx);
 	if (rnd_timeout_pending == 0) {
 		rnd_timeout_pending = 1;
 		callout_schedule(&rnd_callout, 1);
+	}
 	mutex_spin_exit(&rnd_mtx);
+}
 void
 rndsink_detach(rndsink_t *rs)
+{
 	rndsink_t *sink, *tsink;
 #ifdef RND_VERBOSE
 	printf("rnd: entropy sink \"%s\" no longer wants data.\n", rs->name);
 #endif
 	KASSERT(mutex_owned(&rs->mtx));
 	mutex_spin_enter(&rndsink_mtx);
 	TAILQ_FOREACH_SAFE(sink, &rnd_sinks, tailq, tsink) {
 		if (sink == rs) {
 			TAILQ_REMOVE(&rnd_sinks, rs, tailq);
+		}
+	}
 	mutex_spin_exit(&rndsink_mtx);
+}
 void
 rnd_seed(void *base, size_t len)
+{
 	SHA1_CTX s;
 	uint8_t digest[SHA1_DIGEST_LENGTH];
 	if (len != sizeof(*boot_rsp)) {
 		aprint_error("rnd: bad seed length %d\n", (int)len);
 		return;
+	}
 	boot_rsp = (rndsave_t *)base;
 	SHA1Init(&s);
 	SHA1Update(&s, (uint8_t *)&boot_rsp->entropy,
 		   sizeof(boot_rsp->entropy));
 	SHA1Update(&s, boot_rsp->data, sizeof(boot_rsp->data));
 	SHA1Final(digest, &s);
 	if (memcmp(digest, boot_rsp->digest, sizeof(digest))) {
 		aprint_error("rnd: bad seed checksum\n");
 		return;
+	}
 	/*
 	 * It's not really well-defined whether bootloader-supplied
 	 * modules run before or after rnd_init().  Handle both cases.
 	 */
 	if (rnd_ready) {
 #ifdef RND_VERBOSE
 		printf("rnd: ready, feeding in seed data directly.\n");
 #endif
 		mutex_spin_enter(&rndpool_mtx);
 		rndpool_add_data(&rnd_pool, boot_rsp->data,
 				 sizeof(boot_rsp->data),
 				 MIN(boot_rsp->entropy, RND_POOLBITS / 2));
 		memset(boot_rsp, 0, sizeof(*boot_rsp));
 		mutex_spin_exit(&rndpool_mtx);
 	} else {
 #ifdef RND_VERBOSE
 		printf("rnd: not ready, deferring seed feed.\n");
 #endif
+	}
+}