Index: pthread.c
===================================================================
RCS file: /cvsroot/src/lib/libpthread/pthread.c,v
retrieving revision 1.164
diff -u -r1.164 pthread.c
--- pthread.c	8 Feb 2020 17:06:03 -0000	1.164
+++ pthread.c	15 Feb 2020 12:47:00 -0000
@@ -181,7 +181,7 @@
 	 * while pthread_keys descriptors are not
 	 * yet allocated.
 	 */
-	pthread__main = pthread_tsd_init(&__pthread_st_size);
+	pthread__main = pthread_tsd_earlyinit(&__pthread_st_size);
 	if (pthread__main == NULL)
 		err(EXIT_FAILURE, "Cannot allocate pthread storage");
 
@@ -257,8 +257,16 @@
 		}
 	}
 
-	/* Tell libc that we're here and it should role-play accordingly. */
+	/*
+	 * Tell libc that we're here and it should role-play accordingly.
+	 *
+	 * pthread_atfork(3) calls malloc(3) and initializes the system malloc.
+	 */
 	pthread_atfork(NULL, NULL, pthread__fork_callback);
+
+	/* Requires functional malloc(3). */
+	pthread_tsd_init();
+
 	__isthreaded = 1;
 }
 
Index: pthread_int.h
===================================================================
RCS file: /cvsroot/src/lib/libpthread/pthread_int.h,v
retrieving revision 1.101
diff -u -r1.101 pthread_int.h
--- pthread_int.h	5 Feb 2020 11:05:10 -0000	1.101
+++ pthread_int.h	15 Feb 2020 12:47:00 -0000
@@ -294,7 +294,8 @@
 	} 								\
         } while (/*CONSTCOND*/0)
 
-void 	*pthread_tsd_init(size_t *) PTHREAD_HIDE;
+void 	*pthread_tsd_earlyinit(size_t *) PTHREAD_HIDE;
+void 	pthread_tsd_init(void) PTHREAD_HIDE;
 void	pthread__destroy_tsd(pthread_t) PTHREAD_HIDE;
 void	pthread__copy_tsd(pthread_t) PTHREAD_HIDE;
 
Index: pthread_mutex.c
===================================================================
RCS file: /cvsroot/src/lib/libpthread/pthread_mutex.c,v
retrieving revision 1.74
diff -u -r1.74 pthread_mutex.c
--- pthread_mutex.c	1 Feb 2020 18:14:16 -0000	1.74
+++ pthread_mutex.c	15 Feb 2020 12:47:00 -0000
@@ -122,14 +122,12 @@
 {
 	uintptr_t type, proto, val, ceil;
 
-#if 0
 	/*
 	 * Always initialize the mutex structure, maybe be used later
 	 * and the cost should be minimal.
 	 */
 	if (__predict_false(__uselibcstub))
 		return __libc_mutex_init_stub(ptm, attr);
-#endif
 
 	pthread__error(EINVAL, "Invalid mutes attribute",
 	    attr == NULL || attr->ptma_magic == _PT_MUTEXATTR_MAGIC);
@@ -619,10 +617,9 @@
 int
 pthread_mutexattr_init(pthread_mutexattr_t *attr)
 {
-#if 0
+
 	if (__predict_false(__uselibcstub))
 		return __libc_mutexattr_init_stub(attr);
-#endif
 
 	attr->ptma_magic = _PT_MUTEXATTR_MAGIC;
 	attr->ptma_private = (void *)PTHREAD_MUTEX_DEFAULT;
Index: pthread_tsd.c
===================================================================
RCS file: /cvsroot/src/lib/libpthread/pthread_tsd.c,v
retrieving revision 1.18
diff -u -r1.18 pthread_tsd.c
--- pthread_tsd.c	25 Dec 2019 00:44:45 -0000	1.18
+++ pthread_tsd.c	15 Feb 2020 12:47:00 -0000
@@ -61,27 +61,13 @@
 #include <stdlib.h>
 #include <stdio.h>
 
-static void
-pthread_tsd_prefork(void)
-{
-	pthread_mutex_lock(&tsd_mutex);
-}
-
-static void
-pthread_tsd_postfork(void)
-{
-	pthread_mutex_unlock(&tsd_mutex);
-}
-
 void *
-pthread_tsd_init(size_t *tlen)
+pthread_tsd_earlyinit(size_t *tlen)
 {
 	char *pkm;
 	size_t alen;
 	char *arena;
 
-	pthread_atfork(pthread_tsd_prefork, pthread_tsd_postfork, pthread_tsd_postfork);
-
 	if ((pkm = pthread__getenv("PTHREAD_KEYS_MAX")) != NULL) {
 		pthread_keys_max = (int)strtol(pkm, NULL, 0);
 		if (pthread_keys_max < _POSIX_THREAD_KEYS_MAX)
@@ -113,6 +99,25 @@
 	return arena;
 }
 
+static void
+pthread_tsd_prefork(void)
+{
+	pthread_mutex_lock(&tsd_mutex);
+}
+
+static void
+pthread_tsd_postfork(void)
+{
+	pthread_mutex_unlock(&tsd_mutex);
+}
+
+void
+pthread_tsd_init(void)
+{
+
+	pthread_atfork(pthread_tsd_prefork, pthread_tsd_postfork, pthread_tsd_postfork);
+}
+
 int
 pthread_key_create(pthread_key_t *key, void (*destructor)(void *))
 {