diff --git a/libc/SYSCALLS.TXT b/libc/SYSCALLS.TXT
index 6465de4..b613401 100644
--- a/libc/SYSCALLS.TXT
+++ b/libc/SYSCALLS.TXT
@@ -94,7 +94,7 @@
 # IMPORTANT: Even though <sys/prctl.h> declares prctl(int, ...), the syscall stub must take 6 arguments
 #            to match the kernel implementation.
 int     prctl(int option, unsigned int arg2, unsigned int arg3, unsigned int arg4, unsigned int arg5) all
-long    arch_prctl(int, unsigned long) x86_64
+long    __arch_prctl:arch_prctl(int, unsigned long) x86_64
 int     capget(cap_user_header_t header, cap_user_data_t data) all
 int     capset(cap_user_header_t header, const cap_user_data_t data) all
 int     sigaltstack(const stack_t*, stack_t*) all
diff --git a/libc/arch-x86_64/bionic/__get_sp.S b/libc/arch-x86_64/bionic/__get_sp.S
new file mode 100644
index 0000000..0c693b3
--- /dev/null
+++ b/libc/arch-x86_64/bionic/__get_sp.S
@@ -0,0 +1,34 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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
+ * COPYRIGHT OWNER 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 <machine/asm.h>
+
+ENTRY(__get_sp)
+  mov  %rsp, %rax
+  ret
+END(__get_sp)
diff --git a/libc/arch-x86_64/bionic/__get_tls.c b/libc/arch-x86_64/bionic/__get_tls.c
new file mode 100644
index 0000000..f21b6b8
--- /dev/null
+++ b/libc/arch-x86_64/bionic/__get_tls.c
@@ -0,0 +1,33 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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
+ * COPYRIGHT OWNER 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.
+ */
+
+void* __get_tls(void) {
+  void* tls;
+  asm ("mov %%fs:0, %0" : "=r"(tls));
+  return tls;
+}
diff --git a/libc/arch-x86_64/bionic/__rt_sigreturn.S b/libc/arch-x86_64/bionic/__rt_sigreturn.S
new file mode 100644
index 0000000..e03bb88
--- /dev/null
+++ b/libc/arch-x86_64/bionic/__rt_sigreturn.S
@@ -0,0 +1,36 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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
+ * COPYRIGHT OWNER 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 <asm/unistd.h>
+#include <machine/asm.h>
+
+ENTRY(__rt_sigreturn)
+  .hidden _C_LABEL(__rt_sigreturn) // TODO: add an ENTRY_PRIVATE macro for x86_64.
+  movl $__NR_rt_sigreturn, %eax
+  syscall
+END(__rt_sigreturn)
diff --git a/libc/arch-x86_64/bionic/__set_tls.c b/libc/arch-x86_64/bionic/__set_tls.c
new file mode 100644
index 0000000..9a69449
--- /dev/null
+++ b/libc/arch-x86_64/bionic/__set_tls.c
@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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
+ * COPYRIGHT OWNER 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 <asm/prctl.h>
+#include <stdint.h>
+
+extern int __arch_prctl(int, unsigned long);
+
+int __set_tls(void* ptr) {
+  // We also need to write the location of the tls to ptr[0].
+  *(void**) ptr = ptr;
+  return __arch_prctl(ARCH_SET_FS, (uintptr_t) ptr);
+}
diff --git a/libc/arch-x86_64/bionic/_exit_with_stack_teardown.S b/libc/arch-x86_64/bionic/_exit_with_stack_teardown.S
new file mode 100644
index 0000000..66105f2
--- /dev/null
+++ b/libc/arch-x86_64/bionic/_exit_with_stack_teardown.S
@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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
+ * COPYRIGHT OWNER 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 <asm/unistd.h>
+#include <machine/asm.h>
+/*
+ * void _exit_with_stack_teardown(void *stackBase, int stackSize, int *retCode)
+ */
+
+ENTRY(_exit_with_stack_teardown)
+    /* we can trash %rbx here since this call should never return. */
+    /* We can also take advantage of the fact that the linux syscall trap
+     * handler saves all the registers, so we don't need a stack to keep
+     * the retCode argument for exit while doing the munmap */
+
+    /* TODO(dmtriyz): No one expects this code to return, so even if
+     * munmap fails, we have to exit. This should probably be fixed, but
+     * since ARM side does the same thing, leave it as is.
+     */
+
+    /* args passed through registers */
+    mov     $__NR_munmap, %eax        /* shouldn't change %rdx (retCode) */
+    syscall
+    mov     %rdx, %rdi                /* retrieve the retCode */
+    mov     $__NR_exit, %eax
+    syscall
+    /* exit does not return */
+    /* can't have a ret here since we no longer have a usable stack. Seems
+     * that presently, 'hlt' will cause the program to segfault.. but this
+     * should never happen :) */
+    hlt
diff --git a/libc/arch-x86_64/bionic/_setjmp.S b/libc/arch-x86_64/bionic/_setjmp.S
new file mode 100644
index 0000000..d9a59f7
--- /dev/null
+++ b/libc/arch-x86_64/bionic/_setjmp.S
@@ -0,0 +1,82 @@
+/*	$OpenBSD: _setjmp.S,v 1.1 2004/01/28 01:44:45 mickey Exp $	*/
+/*	$NetBSD: _setjmp.S,v 1.1 2001/06/19 00:25:02 fvdl Exp $	*/
+
+/*
+ * Copyright (c) 2001 Wasabi Systems, Inc.
+ * All rights reserved.
+ *
+ * Written by Frank van der Linden for Wasabi Systems, Inc.
+ *
+ * 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. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *      This product includes software developed for the NetBSD Project by
+ *      Wasabi Systems, Inc.
+ * 4. The name of Wasabi Systems, Inc. may not be used to endorse
+ *    or promote products derived from this software without specific prior
+ *    written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``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 WASABI SYSTEMS, INC
+ * 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 <machine/asm.h>
+#include <machine/setjmp.h>
+
+/*
+ * C library -- _setjmp, _longjmp
+ *
+ *	_longjmp(a,v)
+ * will generate a "return(v)" from the last call to
+ *	_setjmp(a)
+ * by restoring registers from the stack.
+ * The previous signal state is NOT restored.
+ */
+
+ENTRY(_setjmp)
+	movq    (%rsp),%r11
+	movq    %rbx,(_JB_RBX * 8)(%rdi)
+	movq    %rbp,(_JB_RBP * 8)(%rdi)
+	movq    %r12,(_JB_R12 * 8)(%rdi)
+	movq    %r13,(_JB_R13 * 8)(%rdi)
+	movq    %r14,(_JB_R14 * 8)(%rdi)
+	movq    %r15,(_JB_R15 * 8)(%rdi)
+	movq    %rsp,(_JB_RSP * 8)(%rdi)
+	movq    %r11,(_JB_PC  * 8)(%rdi)
+
+	xorl	%eax,%eax
+	ret
+
+ENTRY(_longjmp)
+	movq    (_JB_RBX * 8)(%rdi),%rbx
+	movq    (_JB_RBP * 8)(%rdi),%rbp
+	movq    (_JB_R12 * 8)(%rdi),%r12
+	movq    (_JB_R13 * 8)(%rdi),%r13
+	movq    (_JB_R14 * 8)(%rdi),%r14
+	movq    (_JB_R15 * 8)(%rdi),%r15
+	movq    (_JB_RSP * 8)(%rdi),%rsp
+	movq    (_JB_PC  * 8)(%rdi),%r11
+
+	movl	%esi,%eax
+	testl	%eax,%eax
+	jnz	1f
+	incl	%eax
+1:	movq	%r11,0(%rsp)
+	ret
diff --git a/libc/arch-x86_64/bionic/clone.S b/libc/arch-x86_64/bionic/clone.S
new file mode 100644
index 0000000..df2929e
--- /dev/null
+++ b/libc/arch-x86_64/bionic/clone.S
@@ -0,0 +1,111 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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
+ * COPYRIGHT OWNER 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 <asm/unistd.h>
+#include <machine/asm.h>
+
+// int  __pthread_clone(void* (*fn)(void*), void* tls, int flags, void* arg);
+ENTRY(__pthread_clone)
+        # save tls
+        movq    %rsi, %r11
+        # 16-byte alignment on child stack
+        andq    $~15, %rsi
+
+        # insert arguments onto the child stack
+        movq    %rdi, -32(%rsi)
+        movq    %rcx, -24(%rsi)
+        movq    %r11, -16(%rsi)
+
+        subq    $32, %rsi
+        movq    %rdx, %rdi
+        movl    $__NR_clone, %eax
+        syscall
+        testl   %eax, %eax
+        jns     1f
+
+        # an error occurred, set errno and return -1
+        negl    %eax
+        movl    %eax, %edi
+        call    __set_errno
+        orl     $-1, %eax
+        jmp     2f
+1:
+        jnz     2f
+
+        # we're in the child thread now, call __thread_entry
+        # with the appropriate arguments on the child stack
+        # we already placed most of them
+        call    __thread_entry
+        hlt
+2:
+        ret
+
+/*
+ * int  __bionic_clone(unsigned long clone_flags,
+ *                     void*         newsp,
+ *                     int           *parent_tidptr,
+ *                     void          *new_tls,
+ *                     int           *child_tidptr,
+ *                     int           (*fn)(void *),
+ *                     void          *arg);
+ */
+ENTRY(__bionic_clone)
+        # insert arguments onto the child stack
+        andq    $~15, %rsi
+        movq    %r9, -16(%rsi)
+        # 7th argument (arg) goes through stack
+        movq    8(%rsp), %rax
+        movq    %rax, -8(%rsi)
+
+        subq    $16, %rsi
+        movq    %r8, %r10
+        movq    %rcx, %r8
+        movl    $__NR_clone, %eax
+        syscall
+        testl   %eax, %eax
+        jns     1f
+
+        # an error occurred, set errno and return -1
+        negl    %eax
+        movl    %eax, %edi
+        call    __set_errno
+        orl     $-1, %eax
+        jmp     2f
+
+1:
+        jnz     2f
+
+        # we're in the child now, call __bionic_clone_entry
+        # with the appropriate arguments on the child stack
+        # we already placed most of them
+        call    __bionic_clone_entry
+        hlt
+
+2:
+        ret
+
diff --git a/libc/arch-x86_64/bionic/futex_x86_64.S b/libc/arch-x86_64/bionic/futex_x86_64.S
new file mode 100644
index 0000000..d94792e
--- /dev/null
+++ b/libc/arch-x86_64/bionic/futex_x86_64.S
@@ -0,0 +1,67 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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
+ * COPYRIGHT OWNER 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 <asm/unistd.h>
+#include <machine/asm.h>
+
+#define FUTEX_WAIT 0
+#define FUTEX_WAKE 1
+
+/*
+ * int __futex_wait(volatile void *ftx, int val, const struct timespec *timeout)
+ */
+ENTRY(__futex_wait)
+    mov     %rdx, %r10           /* timeout */
+    mov     %esi, %edx           /* val */
+    mov     $FUTEX_WAIT, %esi    /* op */
+    mov     $__NR_futex, %eax
+    syscall
+    ret
+
+
+/* int __futex_wake(volatile void *ftx, int count) */
+
+ENTRY(__futex_wake)
+    mov     %esi, %edx
+    mov     $FUTEX_WAKE, %esi
+    mov     $__NR_futex, %eax
+    syscall
+    ret
+
+/* int __futex_syscall3(volatile void *ftx, int op, int count) */
+ENTRY(__futex_syscall3)
+    mov     $__NR_futex, %eax
+    syscall
+    ret
+
+/* int __futex_syscall4(volatile void *ftx, int op, int val, const struct timespec *timeout) */
+ENTRY(__futex_syscall4)
+    mov     %rcx, %r10      /* timeout */
+    mov     $__NR_futex, %eax
+    syscall
+    ret
diff --git a/libc/arch-x86_64/bionic/setjmp.S b/libc/arch-x86_64/bionic/setjmp.S
new file mode 100644
index 0000000..1641add
--- /dev/null
+++ b/libc/arch-x86_64/bionic/setjmp.S
@@ -0,0 +1,103 @@
+/*	$OpenBSD: setjmp.S,v 1.3 2012/08/22 17:19:34 pascal Exp $	*/
+/*	$NetBSD: __setjmp14.S,v 1.1 2001/06/19 00:25:02 fvdl Exp $	*/
+
+/*
+ * Copyright (c) 2001 Wasabi Systems, Inc.
+ * All rights reserved.
+ *
+ * Written by Frank van der Linden for Wasabi Systems, Inc.
+ *
+ * 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. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *      This product includes software developed for the NetBSD Project by
+ *      Wasabi Systems, Inc.
+ * 4. The name of Wasabi Systems, Inc. may not be used to endorse
+ *    or promote products derived from this software without specific prior
+ *    written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``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 WASABI SYSTEMS, INC
+ * 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 <machine/asm.h>
+#include <machine/setjmp.h>
+
+/*
+ * C library -- _setjmp, _longjmp
+ *
+ *	longjmp(a,v)
+ * will generate a "return(v)" from the last call to
+ *	setjmp(a)
+ * by restoring registers from the stack.
+ * The previous signal state is restored.
+ */
+
+ENTRY(setjmp)
+	pushq	%rdi
+	xorq	%rdi,%rdi
+#ifdef __PIC__
+	call	PIC_PLT(_C_LABEL(sigblock))
+#else
+	call	_C_LABEL(sigblock)
+#endif
+	popq	%rdi
+	movq	%rax,(_JB_SIGMASK * 8)(%rdi)
+
+	movq	(%rsp),%r11
+	movq	%rbx,(_JB_RBX * 8)(%rdi)
+	movq	%rbp,(_JB_RBP * 8)(%rdi)
+	movq	%r12,(_JB_R12 * 8)(%rdi)
+	movq	%r13,(_JB_R13 * 8)(%rdi)
+	movq	%r14,(_JB_R14 * 8)(%rdi)
+	movq	%r15,(_JB_R15 * 8)(%rdi)
+	movq	%rsp,(_JB_RSP * 8)(%rdi)
+	movq	%r11,(_JB_PC  * 8)(%rdi)
+
+2:	xorl	%eax,%eax
+	ret
+
+ENTRY(longjmp)
+	movq	%rdi,%r12
+	movl	%esi,%r8d
+
+	movq	(_JB_SIGMASK * 8)(%rdi),%rdi
+	pushq	%r8
+#ifdef __PIC__
+	call	PIC_PLT(_C_LABEL(sigsetmask))
+#else
+	call	_C_LABEL(sigsetmask)
+#endif
+	popq	%r8
+	movq	(_JB_RBX * 8)(%r12),%rbx
+	movq	(_JB_RBP * 8)(%r12),%rbp
+	movq	(_JB_R13 * 8)(%r12),%r13
+	movq	(_JB_R14 * 8)(%r12),%r14
+	movq	(_JB_R15 * 8)(%r12),%r15
+	movq	(_JB_RSP * 8)(%r12),%rsp
+	movq	(_JB_PC  * 8)(%r12),%r11
+	movq	(_JB_R12 * 8)(%r12),%r12
+
+	movl	%r8d,%eax
+	testl	%eax,%eax
+	jnz	1f
+	incl	%eax
+1:	movq	%r11,0(%rsp)
+	ret
diff --git a/libc/arch-x86_64/bionic/sigaction.c b/libc/arch-x86_64/bionic/sigaction.c
new file mode 100644
index 0000000..d5622be
--- /dev/null
+++ b/libc/arch-x86_64/bionic/sigaction.c
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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
+ * COPYRIGHT OWNER 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>
+
+extern void __rt_sigreturn(void);
+extern int __rt_sigaction(int, const struct sigaction*, struct sigaction*, size_t);
+
+int sigaction(int sig, const struct sigaction* act, struct sigaction* old_act) {
+  struct sigaction sa;
+
+  if (act != NULL && !(act->sa_flags & SA_RESTORER)) {
+    sa = *act;
+    act = &sa;
+    sa.sa_flags |= SA_RESTORER;
+    sa.sa_restorer = &__rt_sigreturn;
+  }
+
+  int result = __rt_sigaction(sig, act, old_act, sizeof(sigset_t));
+
+  if (old_act != NULL && (old_act->sa_restorer == &__rt_sigreturn)) {
+    old_act->sa_flags &= ~SA_RESTORER;
+  }
+
+  return result;
+}
+
diff --git a/libc/arch-x86_64/bionic/sigprocmask.c b/libc/arch-x86_64/bionic/sigprocmask.c
new file mode 100644
index 0000000..cdafa08
--- /dev/null
+++ b/libc/arch-x86_64/bionic/sigprocmask.c
@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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
+ * COPYRIGHT OWNER 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>
+
+extern int __rt_sigprocmask(int, const sigset_t*, sigset_t*, size_t);
+
+int sigprocmask(int how, const sigset_t* set, sigset_t* old_set) {
+  return __rt_sigprocmask(how, set, old_set, sizeof(sigset_t));
+}
diff --git a/libc/arch-x86_64/bionic/sigsetjmp.S b/libc/arch-x86_64/bionic/sigsetjmp.S
new file mode 100644
index 0000000..51b055a
--- /dev/null
+++ b/libc/arch-x86_64/bionic/sigsetjmp.S
@@ -0,0 +1,107 @@
+/*	$OpenBSD: sigsetjmp.S,v 1.3 2012/08/22 17:19:34 pascal Exp $	*/
+/*	$NetBSD: __setjmp14.S,v 1.1 2001/06/19 00:25:02 fvdl Exp $	*/
+
+/*
+ * Copyright (c) 2001 Wasabi Systems, Inc.
+ * All rights reserved.
+ *
+ * Written by Frank van der Linden for Wasabi Systems, Inc.
+ *
+ * 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. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *      This product includes software developed for the NetBSD Project by
+ *      Wasabi Systems, Inc.
+ * 4. The name of Wasabi Systems, Inc. may not be used to endorse
+ *    or promote products derived from this software without specific prior
+ *    written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``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 WASABI SYSTEMS, INC
+ * 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 <machine/asm.h>
+#include <machine/setjmp.h>
+
+/*
+ * C library -- _setjmp, _longjmp
+ *
+ *	longjmp(a,v)
+ * will generate a "return(v)" from the last call to
+ *	setjmp(a)
+ * by restoring registers from the stack.
+ * The previous signal state is restored.
+ */
+
+ENTRY(sigsetjmp)
+	movl    %esi,(_JB_SIGFLAG  * 8)(%rdi)
+	testl   %esi,%esi
+	jz      2f
+
+	pushq	%rdi
+	xorq	%rdi,%rdi
+#ifdef __PIC__
+	call	PIC_PLT(_C_LABEL(sigblock))
+#else
+	call	_C_LABEL(sigblock)
+#endif
+	popq	%rdi
+	movq	%rax,(_JB_SIGMASK * 8)(%rdi)
+
+2:	movq	(%rsp),%r11
+	movq	%rbx,(_JB_RBX * 8)(%rdi)
+	movq	%rbp,(_JB_RBP * 8)(%rdi)
+	movq	%r12,(_JB_R12 * 8)(%rdi)
+	movq	%r13,(_JB_R13 * 8)(%rdi)
+	movq	%r14,(_JB_R14 * 8)(%rdi)
+	movq	%r15,(_JB_R15 * 8)(%rdi)
+	movq	%rsp,(_JB_RSP * 8)(%rdi)
+	movq	%r11,(_JB_PC  * 8)(%rdi)
+
+2:	xorl	%eax,%eax
+	ret
+
+ENTRY(siglongjmp)
+	movq	%rdi,%r12
+	pushq   %rsi
+	cmpl    $0, (_JB_SIGFLAG * 8)(%rdi)
+	jz      2f
+
+	movq	(_JB_SIGMASK * 8)(%rdi),%rdi
+#ifdef __PIC__
+	call	PIC_PLT(_C_LABEL(sigsetmask))
+#else
+	call	_C_LABEL(sigsetmask)
+#endif
+2:	popq	%rax
+	movq	(_JB_RBX * 8)(%r12),%rbx
+	movq	(_JB_RBP * 8)(%r12),%rbp
+	movq	(_JB_R13 * 8)(%r12),%r13
+	movq	(_JB_R14 * 8)(%r12),%r14
+	movq	(_JB_R15 * 8)(%r12),%r15
+	movq	(_JB_RSP * 8)(%r12),%rsp
+	movq	(_JB_PC  * 8)(%r12),%r11
+	movq	(_JB_R12 * 8)(%r12),%r12
+
+	testl	%eax,%eax
+	jnz	1f
+	incl	%eax
+1:	movq	%r11,0(%rsp)
+	ret
diff --git a/libc/arch-x86_64/bionic/sigsuspend.c b/libc/arch-x86_64/bionic/sigsuspend.c
new file mode 100644
index 0000000..40bfaea
--- /dev/null
+++ b/libc/arch-x86_64/bionic/sigsuspend.c
@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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
+ * COPYRIGHT OWNER 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>
+
+extern int __rt_sigsuspend(const sigset_t*, size_t);
+
+int sigsuspend(const sigset_t* set) {
+  return __rt_sigsuspend(set, sizeof(sigset_t));
+}
diff --git a/libc/arch-x86_64/bionic/syscall.S b/libc/arch-x86_64/bionic/syscall.S
new file mode 100644
index 0000000..6b84ba4
--- /dev/null
+++ b/libc/arch-x86_64/bionic/syscall.S
@@ -0,0 +1,65 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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
+ * COPYRIGHT OWNER 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.
+ */
+
+/*
+ * Generic syscall call.
+ * Upon entry:
+ *   %rax: system call number
+ *   %rdi: arg0 to system call
+ *   %rsi: arg1
+ *   %rdx: arg2
+ *   %rcx: arg3 - syscall expects it at %r10
+ *   %r8: arg4
+ *   %r9: arg5
+ */
+
+#include <asm/unistd.h>
+#include <linux/err.h>
+#include <machine/asm.h>
+
+ENTRY(syscall)
+    # All arguments are passed via registers.
+    # (Not all will be valid, depending on the syscall.)
+    mov     %edi, %eax
+    mov     %rsi, %rdi
+    mov     %rdx, %rsi
+    mov     %rcx, %rdx
+    mov     %r8,  %r10
+    mov     %r9,  %r8
+    mov     8(%rsp), %r9
+
+    # Make the system call.
+    syscall
+    cmpq    $-MAX_ERRNO, %rax
+    jb      1f
+    negl    %eax
+    movl    %eax, %edi
+    call    __set_errno
+    orq     $-1, %rax
+1:
+    ret
diff --git a/libc/arch-x86_64/syscalls.mk b/libc/arch-x86_64/syscalls.mk
index 5a7a880..08fdf38 100644
--- a/libc/arch-x86_64/syscalls.mk
+++ b/libc/arch-x86_64/syscalls.mk
@@ -41,7 +41,7 @@
 syscall_src += arch-x86_64/syscalls/setregid.S
 syscall_src += arch-x86_64/syscalls/chroot.S
 syscall_src += arch-x86_64/syscalls/prctl.S
-syscall_src += arch-x86_64/syscalls/arch_prctl.S
+syscall_src += arch-x86_64/syscalls/__arch_prctl.S
 syscall_src += arch-x86_64/syscalls/capget.S
 syscall_src += arch-x86_64/syscalls/capset.S
 syscall_src += arch-x86_64/syscalls/sigaltstack.S
diff --git a/libc/arch-x86_64/syscalls/arch_prctl.S b/libc/arch-x86_64/syscalls/__arch_prctl.S
similarity index 88%
rename from libc/arch-x86_64/syscalls/arch_prctl.S
rename to libc/arch-x86_64/syscalls/__arch_prctl.S
index eaf9494..21d154c 100644
--- a/libc/arch-x86_64/syscalls/arch_prctl.S
+++ b/libc/arch-x86_64/syscalls/__arch_prctl.S
@@ -3,7 +3,7 @@
 #include <linux/err.h>
 #include <machine/asm.h>
 
-ENTRY(arch_prctl)
+ENTRY(__arch_prctl)
     movl    $__NR_arch_prctl, %eax
     syscall
     cmpq    $-MAX_ERRNO, %rax
@@ -14,4 +14,4 @@
     orq     $-1, %rax
 1:
     ret
-END(arch_prctl)
+END(__arch_prctl)
diff --git a/libc/arch-x86_64/x86_64.mk b/libc/arch-x86_64/x86_64.mk
index 6a2bb9c..d9c8f12 100644
--- a/libc/arch-x86_64/x86_64.mk
+++ b/libc/arch-x86_64/x86_64.mk
@@ -1,17 +1,18 @@
 _LIBC_ARCH_COMMON_SRC_FILES := \
-    arch-x86_64/bionic/__get_sp.S \
-    arch-x86_64/bionic/__get_tls.c \
-    arch-x86_64/bionic/__set_tls.c \
     arch-x86_64/bionic/clone.S \
     arch-x86_64/bionic/_exit_with_stack_teardown.S \
     arch-x86_64/bionic/futex_x86_64.S \
-    arch-x86_64/bionic/setjmp.S \
+    arch-x86_64/bionic/__get_sp.S \
+    arch-x86_64/bionic/__get_tls.c \
+    arch-x86_64/bionic/__rt_sigreturn.S \
     arch-x86_64/bionic/_setjmp.S \
-    arch-x86_64/bionic/sigsetjmp.S \
-    arch-x86_64/bionic/syscall.S \
-    arch-x86_64/bionic/sigprocmask.c \
+    arch-x86_64/bionic/setjmp.S \
+    arch-x86_64/bionic/__set_tls.c \
     arch-x86_64/bionic/sigaction.c \
+    arch-x86_64/bionic/sigprocmask.c \
+    arch-x86_64/bionic/sigsetjmp.S \
     arch-x86_64/bionic/sigsuspend.c \
+    arch-x86_64/bionic/syscall.S \
 
 _LIBC_ARCH_STATIC_SRC_FILES := \
     bionic/dl_iterate_phdr_static.c \