Index: lib/sanitizer_common/CMakeLists.txt
===================================================================
--- lib/sanitizer_common/CMakeLists.txt
+++ lib/sanitizer_common/CMakeLists.txt
@@ -104,6 +104,7 @@
   sanitizer_symbolizer_mac.h
   sanitizer_syscall_generic.inc
   sanitizer_syscall_linux_x86_64.inc
+  sanitizer_syscall_linux_aarch64.inc
   sanitizer_thread_registry.h)
 
 set(SANITIZER_COMMON_DEFINITIONS)
Index: lib/sanitizer_common/sanitizer_linux.cc
===================================================================
--- lib/sanitizer_common/sanitizer_linux.cc
+++ lib/sanitizer_common/sanitizer_linux.cc
@@ -98,6 +98,8 @@
 
 #if SANITIZER_LINUX && defined(__x86_64__)
 #include "sanitizer_syscall_linux_x86_64.inc"
+#elif SANITIZER_LINUX && defined(__aarch64__)
+#include "sanitizer_syscall_linux_aarch64.inc"
 #else
 #include "sanitizer_syscall_generic.inc"
 #endif
Index: lib/sanitizer_common/sanitizer_syscall_linux_aarch64.inc
===================================================================
--- /dev/null
+++ lib/sanitizer_common/sanitizer_syscall_linux_aarch64.inc
@@ -0,0 +1,138 @@
+//===-- sanitizer_syscall_linux_aarch64.inc --------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Implementations of internal_syscall and internal_iserror for Linux/aarch64.
+//
+//===----------------------------------------------------------------------===//
+
+#define SYSCALL(name) __NR_ ## name
+
+static uptr __internal_syscall(u64 nr) {
+  register u64 x8 asm("x8") = nr;
+  register u64 x0 asm("x0");
+  asm volatile("svc 0"
+               : "=r"(x0)
+               : "r"(x8)
+               : "memory", "cc");
+  return x0;
+}
+#define __internal_syscall0(n) \
+  (__internal_syscall)(n)
+
+static uptr __internal_syscall(u64 nr, u64 arg1) {
+  register u64 x8 asm("x8") = nr;
+  register u64 x0 asm("x0") = arg1;
+  asm volatile("svc 0"
+               : "=r"(x0)
+               : "r"(x8), "0"(x0)
+               : "memory", "cc");
+  return x0;
+}
+#define __internal_syscall1(n, a1) \
+  (__internal_syscall)(n, (u64)(a1))
+
+static uptr __internal_syscall(u64 nr, u64 arg1, long arg2) {
+  register u64 x8 asm("x8") = nr;
+  register u64 x0 asm("x0") = arg1;
+  register u64 x1 asm("x1") = arg2;
+  asm volatile("svc 0"
+               : "=r"(x0)
+               : "r"(x8), "0"(x0), "r"(x1)
+               : "memory", "cc");
+  return x0;
+}
+#define __internal_syscall2(n, a1, a2) \
+  (__internal_syscall)(n, (u64)(a1), (long)(a2))
+
+static uptr __internal_syscall(u64 nr, u64 arg1, long arg2, long arg3) {
+  register u64 x8 asm("x8") = nr;
+  register u64 x0 asm("x0") = arg1;
+  register u64 x1 asm("x1") = arg2;
+  register u64 x2 asm("x2") = arg3;
+  asm volatile("svc 0"
+               : "=r"(x0)
+               : "r"(x8), "0"(x0), "r"(x1), "r"(x2)
+               : "memory", "cc");
+  return x0;
+}
+#define __internal_syscall3(n, a1, a2, a3) \
+  (__internal_syscall)(n, (u64)(a1), (long)(a2), (long)(a3))
+
+static uptr __internal_syscall(u64 nr, u64 arg1, long arg2, long arg3,
+                               u64 arg4) {
+  register u64 x8 asm("x8") = nr;
+  register u64 x0 asm("x0") = arg1;
+  register u64 x1 asm("x1") = arg2;
+  register u64 x2 asm("x2") = arg3;
+  register u64 x3 asm("x3") = arg4;
+  asm volatile("svc 0"
+               : "=r"(x0)
+               : "r"(x8), "0"(x0), "r"(x1), "r"(x2), "r"(x3)
+               : "memory", "cc");
+  return x0;
+}
+#define __internal_syscall4(n, a1, a2, a3, a4) \
+  (__internal_syscall)(n, (u64)(a1), (long)(a2), (long)(a3), (long)(a4))
+
+static uptr __internal_syscall(u64 nr, u64 arg1, long arg2, long arg3,
+                               u64 arg4, long arg5) {
+  register u64 x8 asm("x8") = nr;
+  register u64 x0 asm("x0") = arg1;
+  register u64 x1 asm("x1") = arg2;
+  register u64 x2 asm("x2") = arg3;
+  register u64 x3 asm("x3") = arg4;
+  register u64 x4 asm("x4") = arg5;
+  asm volatile("svc 0"
+               : "=r"(x0)
+               : "r"(x8), "0"(x0), "r"(x1), "r"(x2), "r"(x3), "r"(x4)
+               : "memory", "cc");
+  return x0;
+}
+#define __internal_syscall5(n, a1, a2, a3, a4, a5) \
+  (__internal_syscall)(n, (u64)(a1), (long)(a2), (long)(a3), (long)(a4), \
+                       (u64)(a5))
+
+static uptr __internal_syscall(u64 nr, u64 arg1, long arg2, long arg3,
+                               u64 arg4, long arg5, long arg6) {
+  register u64 x8 asm("x8") = nr;
+  register u64 x0 asm("x0") = arg1;
+  register u64 x1 asm("x1") = arg2;
+  register u64 x2 asm("x2") = arg3;
+  register u64 x3 asm("x3") = arg4;
+  register u64 x4 asm("x4") = arg5;
+  register u64 x5 asm("x5") = arg6;
+  asm volatile("svc 0"
+               : "=r"(x0)
+               : "r"(x8), "0"(x0), "r"(x1), "r"(x2), "r"(x3), "r"(x4), "r"(x5)
+               : "memory", "cc");
+  return x0;
+}
+#define __internal_syscall6(n, a1, a2, a3, a4, a5, a6) \
+  (__internal_syscall)(n, (u64)(a1), (long)(a2), (long)(a3), (long)(a4), \
+                       (u64)(a5), (long)(a6))
+
+#define __SYSCALL_NARGS_X(a1, a2, a3, a4, a5, a6, a7, a8, n, ...) n
+#define __SYSCALL_NARGS(...) \
+  __SYSCALL_NARGS_X(__VA_ARGS__, 7, 6, 5, 4, 3, 2, 1, 0, )
+#define __SYSCALL_CONCAT_X(a, b) a##b
+#define __SYSCALL_CONCAT(a, b) __SYSCALL_CONCAT_X(a, b)
+#define __SYSCALL_DISP(b, ...) \
+  __SYSCALL_CONCAT(b, __SYSCALL_NARGS(__VA_ARGS__))(__VA_ARGS__)
+
+#define internal_syscall(...) __SYSCALL_DISP(__internal_syscall, __VA_ARGS__)
+
+
+bool internal_iserror(uptr retval, int *rverrno) {
+  if (retval >= (uptr)-4095) {
+    if (rverrno)
+      *rverrno = -retval;
+    return true;
+  }
+  return false;
+}