Debug run. This now works, except that the "live" sources haven't

been tested. With all sources turned on, this unlocks itself in
a couple of seconds! That is no my box, and there is no guarantee
that this will be the case everywhere.

* Cut debug prints.

* Use the same locks/mutexes all the way through.

* Be a tad more conservative about entropy estimates.

4 files changed, 14 insertions, 17 deletions

diff --git a/sys/dev/random/live_entropy_sources.c b/sys/dev/random/live_entropy_sources.c
index d29c94a..7d5ee9b 100644
--- a/sys/dev/random/live_entropy_sources.c
+++ b/sys/dev/random/live_entropy_sources.c
@@ -51,7 +51,6 @@ __FBSDID("$FreeBSD$");
 
 LIST_HEAD(les_head, live_entropy_sources);
 static struct les_head sources = LIST_HEAD_INITIALIZER(sources);
-static struct sx les_lock; /* need a sleepable lock */
 
 #define LES_THRESHOLD 10
 
@@ -65,9 +64,9 @@ live_entropy_source_register(struct random_hardware_source *rsource)
 	les = malloc(sizeof(struct live_entropy_sources), M_ENTROPY, M_WAITOK);
 	les->rsource = rsource;
 
-	sx_xlock(&les_lock);
+	mtx_lock_spin(&harvest_mtx);
 	LIST_INSERT_HEAD(&sources, les, entries);
-	sx_xunlock(&les_lock);
+	mtx_unlock_spin(&harvest_mtx);
 }
 
 void
@@ -77,7 +76,7 @@ live_entropy_source_deregister(struct random_hardware_source *rsource)
 
 	KASSERT(rsource != NULL, ("invalid input to %s", __func__));
 
-	sx_xlock(&les_lock);
+	mtx_lock_spin(&harvest_mtx);
 	LIST_FOREACH(les, &sources, entries) {
 		if (les->rsource == rsource) {
 			LIST_REMOVE(les, entries);
@@ -85,7 +84,7 @@ live_entropy_source_deregister(struct random_hardware_source *rsource)
 			break;
 		}
 	}
-	sx_xunlock(&les_lock);
+	mtx_unlock_spin(&harvest_mtx);
 }
 
 static int
@@ -96,7 +95,7 @@ live_entropy_source_handler(SYSCTL_HANDLER_ARGS)
 
 	count = error = 0;
 
-	sx_slock(&les_lock);
+	mtx_lock_spin(&harvest_mtx);
 
 	if (LIST_EMPTY(&sources))
 		error = SYSCTL_OUT(req, "", 0);
@@ -113,7 +112,7 @@ live_entropy_source_handler(SYSCTL_HANDLER_ARGS)
 		}
 	}
 
-	sx_sunlock(&les_lock);
+	mtx_unlock_spin(&harvest_mtx);
 
 	return (error);
 }
@@ -126,8 +125,6 @@ live_entropy_sources_init(void *unused)
 	    CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE,
 	    NULL, 0, live_entropy_source_handler, "",
 	    "List of Active Live Entropy Sources");
-
-	sx_init(&les_lock, "live_entropy_sources");
 }
 
 /*
@@ -138,6 +135,7 @@ live_entropy_sources_init(void *unused)
  *
  * BEWARE!!!
  * This function runs inside the RNG thread! Don't do anything silly!
+ * The harvest_mtx mutex is held; you may count on that.
  */
 void
 live_entropy_sources_feed(int rounds, event_proc_f entropy_processor)
@@ -147,8 +145,6 @@ live_entropy_sources_feed(int rounds, event_proc_f entropy_processor)
 	struct live_entropy_sources *les;
 	int i, n;
 
-	sx_slock(&les_lock);
-
 	/*
 	 * Walk over all of live entropy sources, and feed their output
 	 * to the system-wide RNG.
@@ -176,15 +172,11 @@ live_entropy_sources_feed(int rounds, event_proc_f entropy_processor)
 		}
 
 	}
-
-	sx_sunlock(&les_lock);
 }
 
 static void
 live_entropy_sources_deinit(void *unused)
 {
-
-	sx_destroy(&les_lock);
 }
 
 SYSINIT(random_adaptors, SI_SUB_DRIVERS, SI_ORDER_FIRST,
diff --git a/sys/dev/random/random_harvestq.c b/sys/dev/random/random_harvestq.c
index 6ae29fd..4e9d711 100644
--- a/sys/dev/random/random_harvestq.c
+++ b/sys/dev/random/random_harvestq.c
@@ -52,7 +52,7 @@ __FBSDID("$FreeBSD$");
 
 /*
  * The harvest mutex protects the consistency of the entropy fifos and
- * empty fifo.
+ * empty fifo and other associated structures.
  */
 struct mtx	harvest_mtx;
 
diff --git a/sys/dev/random/random_harvestq.h b/sys/dev/random/random_harvestq.h
index 11ccfc4..f4e9bb1 100644
--- a/sys/dev/random/random_harvestq.h
+++ b/sys/dev/random/random_harvestq.h
@@ -37,5 +37,6 @@ void random_harvestq_internal(u_int64_t, const void *,
     u_int, u_int, enum esource);
 
 extern int random_kthread_control;
+extern struct mtx harvest_mtx;
 
 #endif /* __RANDOM_HARVEST_H__ */
diff --git a/sys/dev/random/yarrow.c b/sys/dev/random/yarrow.c
index ab26eef..6d2ea3b 100644
--- a/sys/dev/random/yarrow.c
+++ b/sys/dev/random/yarrow.c
@@ -114,7 +114,7 @@ random_process_event(struct harvest *event)
 	struct source *source;
 	enum esource src;
 
-#if 1
+#if 0
 	/* Do this better with DTrace */
 	{
 		int i;
@@ -243,6 +243,10 @@ reseed(u_int fastslow)
 	u_int i;
 	enum esource j;
 
+#if 0
+	printf("Yarrow: %s reseed\n", fastslow == FAST ? "fast" : "slow");
+#endif
+
 	/* The reseed task must not be jumped on */
 	mtx_lock(&random_reseed_mtx);