diff -Paur --no-dereference -- libevent.upstream/bufferevent_sock.c libevent/bufferevent_sock.c
--- libevent.upstream/bufferevent_sock.c
+++ libevent/bufferevent_sock.c
@@ -64,6 +64,7 @@
 #include "event2/util.h"
 #include "event2/bufferevent.h"
 #include "event2/buffer.h"
+#include "event2/buffer_compat.h"
 #include "event2/bufferevent_struct.h"
 #include "event2/bufferevent_compat.h"
 #include "event2/event.h"
@@ -76,6 +77,7 @@
 #endif
 
 /* prototypes */
+void bufferevent_read_pressure_cb(struct evbuffer *, size_t, size_t, void *);
 static int be_socket_enable(struct bufferevent *, short);
 static int be_socket_disable(struct bufferevent *, short);
 static void be_socket_destruct(struct bufferevent *);
@@ -145,6 +147,40 @@
 	}
 }
 
+static int
+bufferevent_add(struct event *ev, struct timeval timeout)
+{
+	struct timeval *ptv = NULL;
+
+	if (timeout.tv_sec || timeout.tv_usec) {
+		ptv = &timeout;
+	}
+
+	return (event_add(ev, ptv));
+}
+
+/*
+ * This callback is executed when the size of the input buffer changes.
+ * We use it to apply back pressure on the reading side.
+ */
+
+/* This API was needed to port OpenBSD's httpd to Sortix. */
+void
+bufferevent_read_pressure_cb(struct evbuffer *buf, size_t old, size_t now,
+    void *arg) {
+	struct bufferevent *bufev = arg;
+	/*
+	 * If we are below the watermark then reschedule reading if it's
+	 * still enabled.
+	 */
+	if (bufev->wm_read.high == 0 || now < bufev->wm_read.high) {
+		evbuffer_setcb(buf, NULL, NULL);
+
+		if (bufev->enabled & EV_READ)
+			bufferevent_add(&bufev->ev_read, bufev->timeout_read);
+	}
+}
+
 static void
 bufferevent_readcb(evutil_socket_t fd, short event, void *arg)
 {
diff -Paur --no-dereference -- libevent.upstream/configure libevent/configure
--- libevent.upstream/configure
+++ libevent/configure
@@ -15961,7 +15961,7 @@
 # which indicates that we try without any flags at all, and "pthread-config"
 # which is a program returning the flags for the Pth emulation library.
 
-acx_pthread_flags="pthreads none -Kthread -kthread lthread -pthread -pthreads -mthreads pthread --thread-safe -mt pthread-config"
+acx_pthread_flags="pthreads none -Kthread -kthread lthread -pthread -pthreads -mthreads pthread --thread-safe -mt"
 
 # The ordering *is* (sometimes) important.  Some notes on the
 # individual items follow:
@@ -16085,8 +16085,8 @@
 main ()
 {
 pthread_t th; pthread_join(th, 0);
-                     pthread_attr_init(0); pthread_cleanup_push(0, 0);
-                     pthread_create(0,0,0,0); pthread_cleanup_pop(0);
+                     pthread_attr_init(0);
+                     pthread_create(0,0,0,0);
   ;
   return 0;
 }
diff -Paur --no-dereference -- libevent.upstream/evutil_rand.c libevent/evutil_rand.c
--- libevent.upstream/evutil_rand.c
+++ libevent/evutil_rand.c
@@ -194,8 +194,8 @@
 void
 evutil_secure_rng_add_bytes(const char *buf, size_t n)
 {
-	arc4random_addrandom((unsigned char*)buf,
-	    n>(size_t)INT_MAX ? INT_MAX : (int)n);
+	(void) buf;
+	(void) n;
 }
 #endif
 
diff -Paur --no-dereference -- libevent.upstream/Makefile.in libevent/Makefile.in
--- libevent.upstream/Makefile.in
+++ libevent/Makefile.in
@@ -200,7 +200,7 @@
 	test/test-ratelim$(EXEEXT) test/test-time$(EXEEXT) \
 	test/test-weof$(EXEEXT) test/regress$(EXEEXT)
 @BUILD_REGRESS_TRUE@am__EXEEXT_6 = $(am__EXEEXT_5)
-PROGRAMS = $(noinst_PROGRAMS)
+PROGRAMS =
 am__vpath_adj_setup = srcdirstrip=`echo "$(srcdir)" | sed 's|.|.|g'`;
 am__vpath_adj = case $$p in \
     $(srcdir)/*) f=`echo "$$p" | sed "s|^$$srcdirstrip/||"`;; \
@@ -2847,6 +2847,7 @@
 	clean-noinstLTLIBRARIES clean-noinstPROGRAMS mostlyclean-am
 
 distclean: distclean-am
+	rm -rf sample/.deps
 	-rm -f $(am__CONFIG_DISTCLEAN_FILES)
 		-rm -f $(DEPDIR)/epoll_sub.Plo
 	-rm -f ./$(DEPDIR)/buffer.Plo
diff -Paur --no-dereference -- libevent.upstream/openssl-compat.h libevent/openssl-compat.h
--- libevent.upstream/openssl-compat.h
+++ libevent/openssl-compat.h
@@ -40,7 +40,8 @@
 #endif /* (OPENSSL_VERSION_NUMBER < 0x10100000L) || \
 	(defined(LIBRESSL_VERSION_NUMBER) && LIBRESSL_VERSION_NUMBER < 0x20700000L) */
 
-#if defined(LIBRESSL_VERSION_NUMBER) && LIBRESSL_VERSION_NUMBER >= 0x20700000L
+#if defined(LIBRESSL_VERSION_NUMBER) && LIBRESSL_VERSION_NUMBER >= 0x20700000L && \
+	LIBRESSL_VERSION_NUMBER < 0x30500000L
 #define BIO_get_init(b) (b)->init
 #endif
 
