--- /dev/null
+# $OpenBSD: Makefile,v 1.1 2018/01/28 13:38:00 otto Exp $
+
+# This test is supposed to print a malloc error and create a core dump
+
+REGRESS_TARGETS= t1
+PROG= malloc_threaderr
+LDADD+= -pthread
+DPADD+= ${LIBPTHREAD}
+
+.include <bsd.regress.mk>
+
+t1: malloc_threaderr
+ ${.OBJDIR}/malloc_threaderror 2>&1 | fgrep 'in free(): bogus pointer (double free?)'
--- /dev/null
+/*
+ * Copyright (c) 2018 Otto Moerbeek <otto@drijf.net>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <err.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <pthread.h>
+
+pthread_cond_t cond;
+pthread_mutex_t mutex;
+
+void *p;
+
+void *m(void *arg)
+{
+ p = malloc(100000);
+ if (p == NULL)
+ err(1, NULL);
+ return NULL;
+}
+
+void *f(void *arg)
+{
+ free(p);
+ free(p);
+ return NULL;
+}
+
+int
+main(void)
+{
+ pthread_t t1, t2;
+
+ printf("This test is supposed to print a malloc error and create a core dump\n");
+
+ if (pthread_create(&t1, NULL, m, NULL))
+ err(1, "pthread_create");
+ pthread_join(t1, NULL);
+
+ if (pthread_create(&t2, NULL, f, NULL))
+ err(1, "pthread_create");
+ pthread_join(t2, NULL);
+
+ return 0;
+}