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Index: head/sys/dev/random/random_harvestq.c
===================================================================
--- head/sys/dev/random/random_harvestq.c
+++ head/sys/dev/random/random_harvestq.c
@@ -34,7 +34,9 @@
#include <sys/param.h>
#include <sys/systm.h>
+#include <sys/ck.h>
#include <sys/conf.h>
+#include <sys/epoch.h>
#include <sys/eventhandler.h>
#include <sys/hash.h>
#include <sys/kernel.h>
@@ -76,6 +78,14 @@
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
+ * concurrency primitives.
+ */
+static __read_mostly bool epoch_inited;
+static __read_mostly epoch_t rs_epoch;
+
+/*
* How many events to queue up. We create this many items in
* an 'empty' queue, then transfer them to the 'harvest' queue with
* supplied junk. When used, they are transferred back to the
@@ -94,12 +104,12 @@
__read_frequently u_int hc_source_mask;
struct random_sources {
- LIST_ENTRY(random_sources) rrs_entries;
+ CK_LIST_ENTRY(random_sources) rrs_entries;
struct random_source *rrs_source;
};
-static LIST_HEAD(sources_head, random_sources) source_list =
- LIST_HEAD_INITIALIZER(source_list);
+static CK_LIST_HEAD(sources_head, random_sources) source_list =
+ CK_LIST_HEAD_INITIALIZER(source_list);
SYSCTL_NODE(_kern_random, OID_AUTO, harvest, CTLFLAG_RW, 0,
"Entropy Device Parameters");
@@ -202,6 +212,14 @@
SYSINIT(random_device_h_proc, SI_SUB_KICK_SCHEDULER, SI_ORDER_ANY, kproc_start,
&random_proc_kp);
+static void
+rs_epoch_init(void *dummy __unused)
+{
+ rs_epoch = epoch_alloc("Random Sources", EPOCH_PREEMPT);
+ epoch_inited = true;
+}
+SYSINIT(rs_epoch_init, SI_SUB_EPOCH, SI_ORDER_ANY, rs_epoch_init, NULL);
+
/*
* Run through all fast sources reading entropy for the given
* number of rounds, which should be a multiple of the number
@@ -211,9 +229,13 @@
random_sources_feed(void)
{
uint32_t entropy[HARVESTSIZE];
+ struct epoch_tracker et;
struct random_sources *rrs;
u_int i, n, local_read_rate;
+ bool rse_warm;
+ rse_warm = epoch_inited;
+
/*
* Step over all of live entropy sources, and feed their output
* to the system-wide RNG.
@@ -223,7 +245,9 @@
local_read_rate = MAX(local_read_rate, 1);
/* But not exceeding RANDOM_KEYSIZE_WORDS */
local_read_rate = MIN(local_read_rate, RANDOM_KEYSIZE_WORDS);
- LIST_FOREACH(rrs, &source_list, rrs_entries) {
+ 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++) {
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)));
@@ -243,6 +267,8 @@
random_harvest_direct(entropy, n, rrs->rrs_source->rs_source);
}
}
+ if (rse_warm)
+ epoch_exit_preempt(rs_epoch, &et);
explicit_bzero(entropy, sizeof(entropy));
}
@@ -573,7 +599,10 @@
random_harvest_register_source(rsource->rs_source);
printf("random: registering fast source %s\n", rsource->rs_ident);
- LIST_INSERT_HEAD(&source_list, rrs, rrs_entries);
+
+ RANDOM_HARVEST_LOCK();
+ CK_LIST_INSERT_HEAD(&source_list, rrs, rrs_entries);
+ RANDOM_HARVEST_UNLOCK();
}
void
@@ -585,29 +614,40 @@
random_harvest_deregister_source(rsource->rs_source);
- LIST_FOREACH(rrs, &source_list, rrs_entries)
+ RANDOM_HARVEST_LOCK();
+ CK_LIST_FOREACH(rrs, &source_list, rrs_entries)
if (rrs->rrs_source == rsource) {
- LIST_REMOVE(rrs, rrs_entries);
+ CK_LIST_REMOVE(rrs, rrs_entries);
break;
}
- if (rrs != NULL)
- free(rrs, M_ENTROPY);
+ RANDOM_HARVEST_UNLOCK();
+
+ if (rrs != NULL && epoch_inited)
+ epoch_wait_preempt(rs_epoch);
+ free(rrs, M_ENTROPY);
}
static int
random_source_handler(SYSCTL_HANDLER_ARGS)
{
+ struct epoch_tracker et;
struct random_sources *rrs;
struct sbuf sbuf;
int error, count;
+ error = sysctl_wire_old_buffer(req, 0);
+ if (error != 0)
+ return (error);
+
sbuf_new_for_sysctl(&sbuf, NULL, 64, req);
count = 0;
- LIST_FOREACH(rrs, &source_list, rrs_entries) {
+ epoch_enter_preempt(rs_epoch, &et);
+ CK_LIST_FOREACH(rrs, &source_list, rrs_entries) {
sbuf_cat(&sbuf, (count++ ? ",'" : "'"));
sbuf_cat(&sbuf, rrs->rrs_source->rs_ident);
sbuf_cat(&sbuf, "'");
}
+ epoch_exit_preempt(rs_epoch, &et);
error = sbuf_finish(&sbuf);
sbuf_delete(&sbuf);
return (error);

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