Update to FreeBSD head 2018-10-23

Git mirror commit 59f44d20be3f99d181ca742e636d45fc39ec982b.

This commit updates OpenSSL to version 1.1.1.  This required an update
of racoon which uses some internal stuff from OpenSSL and seems to be
mostly unmaintained, e.g. there is update in the FreeBSD ports to cope
with OpenSSL 1.1.1.

Update #3472.

1 files changed, 36 insertions, 8 deletions

diff --git a/freebsd/sys/contrib/ck/src/ck_epoch.c b/freebsd/sys/contrib/ck/src/ck_epoch.c
index be0f201d..53b1f7dd 100644
--- a/freebsd/sys/contrib/ck/src/ck_epoch.c
+++ b/freebsd/sys/contrib/ck/src/ck_epoch.c
@@ -129,6 +129,14 @@
  */
 #define CK_EPOCH_GRACE 3U
 
+/*
+ * CK_EPOCH_LENGTH must be a power-of-2 (because (CK_EPOCH_LENGTH - 1) is used
+ * as a mask, and it must be at least 3 (see comments above).
+ */
+#if (CK_EPOCH_LENGTH < 3 || (CK_EPOCH_LENGTH & (CK_EPOCH_LENGTH - 1)) != 0)
+#error "CK_EPOCH_LENGTH must be a power of 2 and >= 3"
+#endif
+
 enum {
 	CK_EPOCH_STATE_USED = 0,
 	CK_EPOCH_STATE_FREE = 1
@@ -350,7 +358,7 @@ ck_epoch_scan(struct ck_epoch *global,
 	return NULL;
 }
 
-static void
+static unsigned int
 ck_epoch_dispatch(struct ck_epoch_record *record, unsigned int e, ck_stack_t *deferred)
 {
 	unsigned int epoch = e & (CK_EPOCH_LENGTH - 1);
@@ -368,6 +376,7 @@ ck_epoch_dispatch(struct ck_epoch_record *record, unsigned int e, ck_stack_t *de
 			ck_stack_push_spnc(deferred, &entry->stack_entry);
 		else
 			entry->function(entry);
+
 		i++;
 	}
 
@@ -383,7 +392,7 @@ ck_epoch_dispatch(struct ck_epoch_record *record, unsigned int e, ck_stack_t *de
 		ck_pr_sub_uint(&record->n_pending, i);
 	}
 
-	return;
+	return i;
 }
 
 /*
@@ -562,16 +571,28 @@ ck_epoch_poll_deferred(struct ck_epoch_record *record, ck_stack_t *deferred)
 	unsigned int epoch;
 	struct ck_epoch_record *cr = NULL;
 	struct ck_epoch *global = record->global;
+	unsigned int n_dispatch;
 
 	epoch = ck_pr_load_uint(&global->epoch);
 
 	/* Serialize epoch snapshots with respect to global epoch. */
 	ck_pr_fence_memory();
+
+	/*
+	 * At this point, epoch is the current global epoch value.
+	 * There may or may not be active threads which observed epoch - 1.
+	 * (ck_epoch_scan() will tell us that). However, there should be
+	 * no active threads which observed epoch - 2.
+	 *
+	 * Note that checking epoch - 2 is necessary, as race conditions can
+	 * allow another thread to increment the global epoch before this
+	 * thread runs.
+	 */
+	n_dispatch = ck_epoch_dispatch(record, epoch - 2, deferred);
+
 	cr = ck_epoch_scan(global, cr, epoch, &active);
-	if (cr != NULL) {
-		record->epoch = epoch;
-		return false;
-	}
+	if (cr != NULL)
+		return (n_dispatch > 0);
 
 	/* We are at a grace period if all threads are inactive. */
 	if (active == false) {
@@ -582,10 +603,17 @@ ck_epoch_poll_deferred(struct ck_epoch_record *record, ck_stack_t *deferred)
 		return true;
 	}
 
-	/* If an active thread exists, rely on epoch observation. */
+	/*
+	 * If an active thread exists, rely on epoch observation.
+	 *
+	 * All the active threads entered the epoch section during
+	 * the current epoch. Therefore, we can now run the handlers
+	 * for the immediately preceding epoch and attempt to
+	 * advance the epoch if it hasn't been already.
+	 */
 	(void)ck_pr_cas_uint(&global->epoch, epoch, epoch + 1);
 
-	ck_epoch_dispatch(record, epoch + 1, deferred);
+	ck_epoch_dispatch(record, epoch - 1, deferred);
 	return true;
 }