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diff --git a/sys/dev/random/fortuna.c b/sys/dev/random/fortuna.c
--- a/sys/dev/random/fortuna.c
+++ b/sys/dev/random/fortuna.c
@@ -73,6 +73,15 @@
#include <dev/random/uint128.h>
#include <dev/random/fortuna.h>
+/*
+ * FS&K discusses reseeding no more frequently than once every 100ms, but does
+ * not seem to discuss how infrequent is too much. The below places an
+ * arbitrary cap on it to make sure we're deliberately raising the roof.
+ */
+#define FORTUNA_RESEED_INTERVAL SBT_1S
+CTASSERT(FORTUNA_RESEED_INTERVAL >= SBT_1S / 10);
+CTASSERT(FORTUNA_RESEED_INTERVAL <= SBT_1S);
+
/* Defined in FS&K */
#define RANDOM_FORTUNA_NPOOLS 32 /* The number of accumulation pools */
#define RANDOM_FORTUNA_DEFPOOLSIZE 64 /* The default pool size/length for a (re)seed */
@@ -470,7 +479,7 @@
* not block initial seeding (fs_lasttime == 0).
*/
|| (__predict_true(fortuna_state.fs_lasttime != 0) &&
- now - fortuna_state.fs_lasttime <= SBT_1S/10)
+ now - fortuna_state.fs_lasttime <= FORTUNA_RESEED_INTERVAL)
#endif
) {
RANDOM_RESEED_UNLOCK();
diff --git a/sys/dev/random/random_harvestq.h b/sys/dev/random/random_harvestq.h
--- a/sys/dev/random/random_harvestq.h
+++ b/sys/dev/random/random_harvestq.h
@@ -42,8 +42,6 @@
uint8_t he_source; /* origin of the entropy */
};
-void read_rate_increment(u_int);
-
#define RANDOM_HARVEST_INIT_LOCK(x) mtx_init(&harvest_context.hc_mtx, "entropy harvest mutex", NULL, MTX_SPIN)
#define RANDOM_HARVEST_LOCK(x) mtx_lock_spin(&harvest_context.hc_mtx)
#define RANDOM_HARVEST_UNLOCK(x) mtx_unlock_spin(&harvest_context.hc_mtx)
diff --git a/sys/dev/random/random_harvestq.c b/sys/dev/random/random_harvestq.c
--- a/sys/dev/random/random_harvestq.c
+++ b/sys/dev/random/random_harvestq.c
@@ -72,11 +72,20 @@
#define _RANDOM_HARVEST_UMA_OFF (1u << RANDOM_UMA)
#endif
+/*
+ * How much entropy to deliver at 10Hz. We want to end up with at least 256
+ * bits per second per pool. We'll end up collecting 32 bits per feed /
+ * 320 bits per second because it's non-trivial to inject partial bytes at the
+ * moment.
+ */
+#define ENTROPY_PER_POOL roundup2((256 / 10) + 1, 32)
+#define ENTROPY_PER_POOL_WORDS (ENTROPY_PER_POOL / (NBBY * sizeof(uint32_t)))
+_Static_assert(ENTROPY_PER_POOL_WORDS <= HARVESTSIZE,
+ "Collecting too much entropy per pool.");
+
static void random_kthread(void);
static void random_sources_feed(void);
-static u_int read_rate;
-
/*
* Random must initialize much earlier than epoch, but we can initialize the
* epoch code before SMP starts. Prior to SMP, we can safely bypass
@@ -228,10 +237,10 @@
static void
random_sources_feed(void)
{
- uint32_t entropy[HARVESTSIZE];
+ uint32_t entropy[ENTROPY_PER_POOL_WORDS];
struct epoch_tracker et;
struct random_sources *rrs;
- u_int i, n, local_read_rate;
+ u_int i, n;
bool rse_warm;
rse_warm = epoch_inited;
@@ -240,15 +249,10 @@
* Step over all of live entropy sources, and feed their output
* to the system-wide RNG.
*/
- local_read_rate = atomic_readandclear_32(&read_rate);
- /* Perform at least one read per round */
- local_read_rate = MAX(local_read_rate, 1);
- /* But not exceeding RANDOM_KEYSIZE_WORDS */
- local_read_rate = MIN(local_read_rate, RANDOM_KEYSIZE_WORDS);
if (rse_warm)
epoch_enter_preempt(rs_epoch, &et);
CK_LIST_FOREACH(rrs, &source_list, rrs_entries) {
- for (i = 0; i < p_random_alg_context->ra_poolcount*local_read_rate; i++) {
+ for (i = 0; i < p_random_alg_context->ra_poolcount; i++) {
n = rrs->rrs_source->rs_read(entropy, sizeof(entropy));
KASSERT((n <= sizeof(entropy)), ("%s: rs_read returned too much data (%u > %zu)", __func__, n, sizeof(entropy)));
/*
@@ -272,13 +276,6 @@
explicit_bzero(entropy, sizeof(entropy));
}
-void
-read_rate_increment(u_int chunk)
-{
-
- atomic_add_32(&read_rate, chunk);
-}
-
/* ARGSUSED */
static int
random_check_uint_harvestmask(SYSCTL_HANDLER_ARGS)
diff --git a/sys/dev/random/randomdev.c b/sys/dev/random/randomdev.c
--- a/sys/dev/random/randomdev.c
+++ b/sys/dev/random/randomdev.c
@@ -187,7 +187,6 @@
if (error != 0)
return (error);
- read_rate_increment(howmany(uio->uio_resid + 1, sizeof(uint32_t)));
total_read = 0;
/* Easy to deal with the trivial 0 byte case. */
@@ -286,7 +285,6 @@
(void)randomdev_wait_until_seeded(SEEDWAIT_UNINTERRUPTIBLE);
}
- read_rate_increment(roundup2(len, sizeof(uint32_t)));
p_random_alg_context->ra_read(random_buf, len);
}

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