diff --git a/libc/unistd/abort.c b/libc/unistd/abort.c
new file mode 100644
index 0000000..3291287
--- /dev/null
+++ b/libc/unistd/abort.c
@@ -0,0 +1,84 @@
+/*	$OpenBSD: abort.c,v 1.14 2005/08/08 08:05:36 espie Exp $ */
+/*
+ * Copyright (c) 1985 Regents of the University of California.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <signal.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include "thread_private.h"
+#include "atexit.h"
+
+void
+abort(void)
+{
+	struct atexit *p = __atexit;
+	static int cleanup_called = 0;
+	sigset_t mask;
+
+  
+	sigfillset(&mask);
+	/*
+	 * don't block SIGABRT to give any handler a chance; we ignore
+	 * any errors -- X311J doesn't allow abort to return anyway.
+	 */
+	sigdelset(&mask, SIGABRT);
+	(void)sigprocmask(SIG_SETMASK, &mask, (sigset_t *)NULL);
+
+	/*
+	 * POSIX requires we flush stdio buffers on abort
+	 */
+	if (cleanup_called == 0) {
+		while (p != NULL && p->next != NULL)
+			p = p->next;
+		if (p != NULL && p->fns[0] != NULL) {
+			cleanup_called = 1;
+			(*p->fns[0])();
+		}
+	}
+
+	(void)kill(getpid(), SIGABRT);
+
+	/*
+	 * if SIGABRT ignored, or caught and the handler returns, do
+	 * it again, only harder.
+	 */
+        {
+            struct sigaction sa;
+
+            sa.sa_handler = SIG_DFL;
+            sa.sa_flags   = SA_RESTART;
+            sigemptyset(&sa.sa_mask);
+
+            (void)sigaction( SIGABRT, &sa, &sa );
+        }
+
+	(void)sigprocmask(SIG_SETMASK, &mask, (sigset_t *)NULL);
+	(void)kill(getpid(), SIGABRT);
+	_exit(1);
+}