diff --git a/src/third_party/linux-syscall-support/METADATA b/src/third_party/linux-syscall-support/METADATA
new file mode 100644
index 0000000..b5273c9
--- /dev/null
+++ b/src/third_party/linux-syscall-support/METADATA
@@ -0,0 +1,21 @@
+name: "linux-syscall-support"
+description:
+  "Linux Syscall Support allows for direct Linux system calls required for "
+  "Crashpad."
+
+third_party {
+  url {
+    type: LOCAL_SOURCE
+    value: "/third_party/linux-syscall-support_mirror"
+  }
+  url {
+    type: GIT
+    value: "https://chromium.googlesource.com/linux-syscall-support"
+  }
+  version: "fd00dbbd0c06a309c657d89e9430143b179ff6db"
+  last_upgrade_date {
+    year: 2020
+    month: 3
+    day: 11
+  }
+}
diff --git a/src/third_party/linux-syscall-support/README.md b/src/third_party/linux-syscall-support/README.md
new file mode 100644
index 0000000..70cbc85
--- /dev/null
+++ b/src/third_party/linux-syscall-support/README.md
@@ -0,0 +1,137 @@
+# Linux Syscall Support (LSS)
+
+Every so often, projects need to directly embed Linux system calls instead of
+calling the implementations in the system runtime library.
+
+This project provides a header file that can be included into your application
+whenever you need to make direct system calls.
+
+The goal is to provide an API that generally mirrors the standard C library
+while still making direct syscalls.  We try to hide some of the differences
+between arches when reasonably feasible.  e.g. Newer architectures no longer
+provide an `open` syscall, but do provide `openat`.  We will still expose a
+`sys_open` helper by default that calls into `openat` instead.
+
+We explicitly do not expose the raw syscall ABI including all of its historical
+warts to the user.  We want people to be able to easily make a syscall, not have
+to worry that on some arches size args are swapped or they are shifted.
+
+Please be sure to review the Caveats section below however.
+
+## How to include linux\_syscall\_support.h in your project
+
+You can either copy the file into your project, or preferably, you can set up
+Git submodules to automatically pull from our source repository.
+
+## Supported targets
+
+The following architectures/ABIs have been tested (at some point) and should
+generally work.  If you don't see your combo listed here, please double check
+the header itself as this list might be out of date.
+
+* x86 32-bit (i.e. i386, i486, i586, i686, Intel, AMD, etc...)
+* [x86_64 64-bit](https://en.wikipedia.org/wiki/X86-64) (i.e. x86-64, amd64, etc...)
+* [x32 32-bit](https://sites.google.com/site/x32abi/)
+* [ARM 32-bit](https://en.wikipedia.org/wiki/ARM_architecture) OABI
+* [ARM 32-bit](https://en.wikipedia.org/wiki/ARM_architecture) EABI (i.e. armv6, armv7, etc...)
+* AARCH64 64-bit (i.e. arm64, armv8, etc...)
+* PowerPC 32-bit (i.e. ppc, ppc32, etc...)
+* MIPS 32-bit o32 ABI
+* MIPS 32-bit n32 ABI
+* MIPS 64-bit n64 ABI
+
+## API
+
+By default, you can just add a `sys_` prefix to any function you want to call.
+So if you want to call `open(...)`, use `sys_open(...)` instead.
+
+### Knobs
+
+The linux\_syscall\_support.h header provides many knobs for you to control
+the exported API.  These are all documented in the top of the header in a big
+comment block, so refer to that instead.
+
+## Caveats
+
+### ABI differences
+
+Some functions that the standard C library exposes use a different ABI than
+what the Linux kernel uses.  Care must be taken when making syscalls directly
+that you use the right structure and flags.  e.g. Most C libraries define a
+`struct stat` (commonly in `sys/stat.h` or `bits/stat.h`) that is different
+from the `struct stat` the kernel uses (commonly in `asm/stat.h`).  If you use
+the wrong structure layout, then you can see errors like memory corruption or
+weird/shifted values.  If you plan on making syscalls directly, you should
+focus on headers that are available under the `linux/` and `asm/` namespaces.
+
+Note: LSS provides structs for most of these cases.  For `sys_stat()`, it
+provides `struct kernel_stat` for you to use.
+
+### Transparent backwards compatibility with older kernels
+
+While some C libraries (notably, glibc) take care to fallback to older syscalls
+when running on older kernels, there is no such support in LSS.  If you plan on
+trying to run on older kernels, you will need to handle errors yourself (e.g.
+`ENOSYS` when using a too new syscall).
+
+Remember that this can happen with new flag bits too.  e.g. The `O_CLOEXEC`
+flag was added to many syscalls, but if you try to run use it on older kernels,
+it will fail with `EINVAL`.  In that case, you must handle the fallback logic
+yourself.
+
+### Variable arguments (varargs)
+
+We do not support vararg type functions.  e.g. While the standard `open()`
+function can accept 2 or 3 arguments (with the mode field being optional),
+the `sys_open()` function always requires 3 arguments.
+
+## Bug reports & feature requests
+
+If you wish to report a problem or request a feature, please file them in our
+[bug tracker](https://bugs.chromium.org/p/linux-syscall-support/issues/).
+
+Please do not post patches to the tracker.  Instead, see below for how to send
+patches to us directly.
+
+While we welcome feature requests, please keep in mind that it is unlikely that
+anyone will find time to implement them for you.  Sending patches is strongly
+preferred and will often move things much faster.
+
+## Projects that use LSS
+
+* [Chromium](https://www.chromium.org/)
+* [Breakpad](https://chromium.googlesource.com/breakpad/breakpad)
+* [Native Client](https://developer.chrome.com/native-client), in nacl\_bootstrap.c
+
+## How to get an LSS change committed
+
+### Review
+
+You get your change reviewed, you can upload it to
+[Gerrit](https://chromium-review.googlesource.com/q/project:linux-syscall-support+status:open)
+using `git cl upload` from
+[Chromium's depot-tools](https://commondatastorage.googleapis.com/chrome-infra-docs/flat/depot_tools/docs/html/depot_tools_tutorial.html).
+
+### Testing
+
+Tests are found in the [tests/](./tests/) subdirectory.  It does not (yet) offer
+100% coverage, but should grow over time.
+
+New commits that update/change/add syscall wrappers should include tests for
+them too.  Consult the [test documentation](./tests/README.md) for more details.
+
+To run, just run `make` inside the tests directory.  It will compile & execute
+the tests locally.
+
+There is some limited cross-compile coverage available if you run `make cross`.
+It only compiles things (does not execute at all).
+
+### Rolling into Chromium
+
+If you commit a change to LSS, please also commit a Chromium change to update
+`lss_revision` in
+[Chromium's DEPS](https://chromium.googlesource.com/chromium/src/+/master/DEPS)
+file.
+
+This ensures that the LSS change gets tested, so that people who commit later
+LSS changes don't run into problems with updating `lss_revision`.
diff --git a/src/third_party/linux-syscall-support/linux_syscall_support.h b/src/third_party/linux-syscall-support/linux_syscall_support.h
new file mode 100644
index 0000000..a177cfb
--- /dev/null
+++ b/src/third_party/linux-syscall-support/linux_syscall_support.h
@@ -0,0 +1,4536 @@
+/* Copyright (c) 2005-2011, Google Inc.
+ * 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.
+ *     * Neither the name of Google Inc. 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 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.
+ *
+ * ---
+ * Author: Markus Gutschke
+ */
+
+/* This file includes Linux-specific support functions common to the
+ * coredumper and the thread lister; primarily, this is a collection
+ * of direct system calls, and a couple of symbols missing from
+ * standard header files.
+ * There are a few options that the including file can set to control
+ * the behavior of this file:
+ *
+ * SYS_CPLUSPLUS:
+ *   The entire header file will normally be wrapped in 'extern "C" { }",
+ *   making it suitable for compilation as both C and C++ source. If you
+ *   do not want to do this, you can set the SYS_CPLUSPLUS macro to inhibit
+ *   the wrapping. N.B. doing so will suppress inclusion of all prerequisite
+ *   system header files, too. It is the caller's responsibility to provide
+ *   the necessary definitions.
+ *
+ * SYS_ERRNO:
+ *   All system calls will update "errno" unless overriden by setting the
+ *   SYS_ERRNO macro prior to including this file. SYS_ERRNO should be
+ *   an l-value.
+ *
+ * SYS_INLINE:
+ *   New symbols will be defined "static inline", unless overridden by
+ *   the SYS_INLINE macro.
+ *
+ * SYS_LINUX_SYSCALL_SUPPORT_H
+ *   This macro is used to avoid multiple inclusions of this header file.
+ *   If you need to include this file more than once, make sure to
+ *   unset SYS_LINUX_SYSCALL_SUPPORT_H before each inclusion.
+ *
+ * SYS_PREFIX:
+ *   New system calls will have a prefix of "sys_" unless overridden by
+ *   the SYS_PREFIX macro. Valid values for this macro are [0..9] which
+ *   results in prefixes "sys[0..9]_". It is also possible to set this
+ *   macro to -1, which avoids all prefixes.
+ *
+ * SYS_SYSCALL_ENTRYPOINT:
+ *   Some applications (such as sandboxes that filter system calls), need
+ *   to be able to run custom-code each time a system call is made. If this
+ *   macro is defined, it expands to the name of a "common" symbol. If
+ *   this symbol is assigned a non-NULL pointer value, it is used as the
+ *   address of the system call entrypoint.
+ *   A pointer to this symbol can be obtained by calling
+ *   get_syscall_entrypoint()
+ *
+ * This file defines a few internal symbols that all start with "LSS_".
+ * Do not access these symbols from outside this file. They are not part
+ * of the supported API.
+ */
+#ifndef SYS_LINUX_SYSCALL_SUPPORT_H
+#define SYS_LINUX_SYSCALL_SUPPORT_H
+
+/* We currently only support x86-32, x86-64, ARM, MIPS, PPC, s390 and s390x
+ * on Linux.
+ * Porting to other related platforms should not be difficult.
+ */
+#if (defined(__i386__) || defined(__x86_64__) || defined(__ARM_ARCH_3__) ||   \
+     defined(__mips__) || defined(__PPC__) || defined(__ARM_EABI__) || \
+     defined(__aarch64__) || defined(__s390__)) \
+  && (defined(__linux) || defined(__ANDROID__))
+
+#ifndef SYS_CPLUSPLUS
+#ifdef __cplusplus
+/* Some system header files in older versions of gcc neglect to properly
+ * handle being included from C++. As it appears to be harmless to have
+ * multiple nested 'extern "C"' blocks, just add another one here.
+ */
+extern "C" {
+#endif
+
+#include <errno.h>
+#include <fcntl.h>
+#include <sched.h>
+#include <signal.h>
+#include <stdarg.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <string.h>
+#include <sys/ptrace.h>
+#include <sys/resource.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+#include <linux/unistd.h>
+#include <endian.h>
+
+#ifdef __mips__
+/* Include definitions of the ABI currently in use.                          */
+#ifdef __ANDROID__
+/* Android doesn't have sgidefs.h, but does have asm/sgidefs.h,
+ * which has the definitions we need.
+ */
+#include <asm/sgidefs.h>
+#else
+#include <sgidefs.h>
+#endif
+#endif
+#endif
+
+/* Some libcs, for example Android NDK and musl, #define these
+ * macros as aliases to their non-64 counterparts. To avoid naming
+ * conflict, remove them.
+ *
+ * These are restored by the corresponding #pragma pop_macro near
+ * the end of this file.
+ */
+#pragma push_macro("stat64")
+#pragma push_macro("fstat64")
+#pragma push_macro("lstat64")
+#pragma push_macro("pread64")
+#pragma push_macro("pwrite64")
+#pragma push_macro("getdents64")
+#undef stat64
+#undef fstat64
+#undef lstat64
+#undef pread64
+#undef pwrite64
+#undef getdents64
+
+#if defined(__ANDROID__) && defined(__x86_64__)
+// A number of x86_64 syscalls are blocked by seccomp on recent Android;
+// undefine them so that modern alternatives will be used instead where
+// possible.
+// The alternative syscalls have been sanity checked against linux-3.4+;
+// older versions might not work.
+# undef __NR_getdents
+# undef __NR_dup2
+# undef __NR_fork
+# undef __NR_getpgrp
+# undef __NR_open
+# undef __NR_poll
+# undef __NR_readlink
+# undef __NR_stat
+# undef __NR_unlink
+# undef __NR_pipe
+#endif
+
+#if defined(__ANDROID__)
+// waitpid is blocked by seccomp on all architectures on recent Android.
+# undef __NR_waitpid
+#endif
+
+/* As glibc often provides subtly incompatible data structures (and implicit
+ * wrapper functions that convert them), we provide our own kernel data
+ * structures for use by the system calls.
+ * These structures have been developed by using Linux 2.6.23 headers for
+ * reference. Note though, we do not care about exact API compatibility
+ * with the kernel, and in fact the kernel often does not have a single
+ * API that works across architectures. Instead, we try to mimic the glibc
+ * API where reasonable, and only guarantee ABI compatibility with the
+ * kernel headers.
+ * Most notably, here are a few changes that were made to the structures
+ * defined by kernel headers:
+ *
+ * - we only define structures, but not symbolic names for kernel data
+ *   types. For the latter, we directly use the native C datatype
+ *   (i.e. "unsigned" instead of "mode_t").
+ * - in a few cases, it is possible to define identical structures for
+ *   both 32bit (e.g. i386) and 64bit (e.g. x86-64) platforms by
+ *   standardizing on the 64bit version of the data types. In particular,
+ *   this means that we use "unsigned" where the 32bit headers say
+ *   "unsigned long".
+ * - overall, we try to minimize the number of cases where we need to
+ *   conditionally define different structures.
+ * - the "struct kernel_sigaction" class of structures have been
+ *   modified to more closely mimic glibc's API by introducing an
+ *   anonymous union for the function pointer.
+ * - a small number of field names had to have an underscore appended to
+ *   them, because glibc defines a global macro by the same name.
+ */
+
+/* include/linux/dirent.h                                                    */
+struct kernel_dirent64 {
+  unsigned long long d_ino;
+  long long          d_off;
+  unsigned short     d_reclen;
+  unsigned char      d_type;
+  char               d_name[256];
+};
+
+/* include/linux/dirent.h                                                    */
+#if !defined(__NR_getdents)
+// when getdents is not available, getdents64 is used for both.
+#define kernel_dirent kernel_dirent64
+#else
+struct kernel_dirent {
+  long               d_ino;
+  long               d_off;
+  unsigned short     d_reclen;
+  char               d_name[256];
+};
+#endif
+
+/* include/linux/uio.h                                                       */
+struct kernel_iovec {
+  void               *iov_base;
+  unsigned long      iov_len;
+};
+
+/* include/linux/socket.h                                                    */
+struct kernel_msghdr {
+  void               *msg_name;
+  int                msg_namelen;
+  struct kernel_iovec*msg_iov;
+  unsigned long      msg_iovlen;
+  void               *msg_control;
+  unsigned long      msg_controllen;
+  unsigned           msg_flags;
+};
+
+/* include/asm-generic/poll.h                                                */
+struct kernel_pollfd {
+  int                fd;
+  short              events;
+  short              revents;
+};
+
+/* include/linux/resource.h                                                  */
+struct kernel_rlimit {
+  unsigned long      rlim_cur;
+  unsigned long      rlim_max;
+};
+
+/* include/linux/time.h                                                      */
+struct kernel_timespec {
+  long               tv_sec;
+  long               tv_nsec;
+};
+
+/* include/linux/time.h                                                      */
+struct kernel_timeval {
+  long               tv_sec;
+  long               tv_usec;
+};
+
+/* include/linux/resource.h                                                  */
+struct kernel_rusage {
+  struct kernel_timeval ru_utime;
+  struct kernel_timeval ru_stime;
+  long               ru_maxrss;
+  long               ru_ixrss;
+  long               ru_idrss;
+  long               ru_isrss;
+  long               ru_minflt;
+  long               ru_majflt;
+  long               ru_nswap;
+  long               ru_inblock;
+  long               ru_oublock;
+  long               ru_msgsnd;
+  long               ru_msgrcv;
+  long               ru_nsignals;
+  long               ru_nvcsw;
+  long               ru_nivcsw;
+};
+
+#if defined(__i386__) || defined(__ARM_EABI__) || defined(__ARM_ARCH_3__) \
+  || defined(__PPC__) || (defined(__s390__) && !defined(__s390x__))
+
+/* include/asm-{arm,i386,mips,ppc}/signal.h                                  */
+struct kernel_old_sigaction {
+  union {
+    void             (*sa_handler_)(int);
+    void             (*sa_sigaction_)(int, siginfo_t *, void *);
+  };
+  unsigned long      sa_mask;
+  unsigned long      sa_flags;
+  void               (*sa_restorer)(void);
+} __attribute__((packed,aligned(4)));
+#elif (defined(__mips__) && _MIPS_SIM == _MIPS_SIM_ABI32)
+  #define kernel_old_sigaction kernel_sigaction
+#elif defined(__aarch64__)
+  // No kernel_old_sigaction defined for arm64.
+#endif
+
+/* Some kernel functions (e.g. sigaction() in 2.6.23) require that the
+ * exactly match the size of the signal set, even though the API was
+ * intended to be extensible. We define our own KERNEL_NSIG to deal with
+ * this.
+ * Please note that glibc provides signals [1.._NSIG-1], whereas the
+ * kernel (and this header) provides the range [1..KERNEL_NSIG]. The
+ * actual number of signals is obviously the same, but the constants
+ * differ by one.
+ */
+#ifdef __mips__
+#define KERNEL_NSIG 128
+#else
+#define KERNEL_NSIG  64
+#endif
+
+/* include/asm-{arm,aarch64,i386,mips,x86_64}/signal.h                       */
+struct kernel_sigset_t {
+  unsigned long sig[(KERNEL_NSIG + 8*sizeof(unsigned long) - 1)/
+                    (8*sizeof(unsigned long))];
+};
+
+/* include/asm-{arm,i386,mips,x86_64,ppc}/signal.h                           */
+struct kernel_sigaction {
+#ifdef __mips__
+  unsigned long      sa_flags;
+  union {
+    void             (*sa_handler_)(int);
+    void             (*sa_sigaction_)(int, siginfo_t *, void *);
+  };
+  struct kernel_sigset_t sa_mask;
+#else
+  union {
+    void             (*sa_handler_)(int);
+    void             (*sa_sigaction_)(int, siginfo_t *, void *);
+  };
+  unsigned long      sa_flags;
+  void               (*sa_restorer)(void);
+  struct kernel_sigset_t sa_mask;
+#endif
+};
+
+/* include/linux/socket.h                                                    */
+struct kernel_sockaddr {
+  unsigned short     sa_family;
+  char               sa_data[14];
+};
+
+/* include/asm-{arm,aarch64,i386,mips,ppc,s390}/stat.h                       */
+#ifdef __mips__
+#if _MIPS_SIM == _MIPS_SIM_ABI64
+struct kernel_stat {
+#else
+struct kernel_stat64 {
+#endif
+  unsigned           st_dev;
+  unsigned           __pad0[3];
+  unsigned long long st_ino;
+  unsigned           st_mode;
+  unsigned           st_nlink;
+  unsigned           st_uid;
+  unsigned           st_gid;
+  unsigned           st_rdev;
+  unsigned           __pad1[3];
+  long long          st_size;
+  unsigned           st_atime_;
+  unsigned           st_atime_nsec_;
+  unsigned           st_mtime_;
+  unsigned           st_mtime_nsec_;
+  unsigned           st_ctime_;
+  unsigned           st_ctime_nsec_;
+  unsigned           st_blksize;
+  unsigned           __pad2;
+  unsigned long long st_blocks;
+};
+#elif defined __PPC__
+struct kernel_stat64 {
+  unsigned long long st_dev;
+  unsigned long long st_ino;
+  unsigned           st_mode;
+  unsigned           st_nlink;
+  unsigned           st_uid;
+  unsigned           st_gid;
+  unsigned long long st_rdev;
+  unsigned short int __pad2;
+  long long          st_size;
+  long               st_blksize;
+  long long          st_blocks;
+  long               st_atime_;
+  unsigned long      st_atime_nsec_;
+  long               st_mtime_;
+  unsigned long      st_mtime_nsec_;
+  long               st_ctime_;
+  unsigned long      st_ctime_nsec_;
+  unsigned long      __unused4;
+  unsigned long      __unused5;
+};
+#else
+struct kernel_stat64 {
+  unsigned long long st_dev;
+  unsigned char      __pad0[4];
+  unsigned           __st_ino;
+  unsigned           st_mode;
+  unsigned           st_nlink;
+  unsigned           st_uid;
+  unsigned           st_gid;
+  unsigned long long st_rdev;
+  unsigned char      __pad3[4];
+  long long          st_size;
+  unsigned           st_blksize;
+  unsigned long long st_blocks;
+  unsigned           st_atime_;
+  unsigned           st_atime_nsec_;
+  unsigned           st_mtime_;
+  unsigned           st_mtime_nsec_;
+  unsigned           st_ctime_;
+  unsigned           st_ctime_nsec_;
+  unsigned long long st_ino;
+};
+#endif
+
+/* include/asm-{arm,aarch64,i386,mips,x86_64,ppc,s390}/stat.h                */
+#if defined(__i386__) || defined(__ARM_ARCH_3__) || defined(__ARM_EABI__)
+struct kernel_stat {
+  /* The kernel headers suggest that st_dev and st_rdev should be 32bit
+   * quantities encoding 12bit major and 20bit minor numbers in an interleaved
+   * format. In reality, we do not see useful data in the top bits. So,
+   * we'll leave the padding in here, until we find a better solution.
+   */
+  unsigned short     st_dev;
+  short              pad1;
+  unsigned           st_ino;
+  unsigned short     st_mode;
+  unsigned short     st_nlink;
+  unsigned short     st_uid;
+  unsigned short     st_gid;
+  unsigned short     st_rdev;
+  short              pad2;
+  unsigned           st_size;
+  unsigned           st_blksize;
+  unsigned           st_blocks;
+  unsigned           st_atime_;
+  unsigned           st_atime_nsec_;
+  unsigned           st_mtime_;
+  unsigned           st_mtime_nsec_;
+  unsigned           st_ctime_;
+  unsigned           st_ctime_nsec_;
+  unsigned           __unused4;
+  unsigned           __unused5;
+};
+#elif defined(__x86_64__)
+struct kernel_stat {
+  uint64_t           st_dev;
+  uint64_t           st_ino;
+  uint64_t           st_nlink;
+  unsigned           st_mode;
+  unsigned           st_uid;
+  unsigned           st_gid;
+  unsigned           __pad0;
+  uint64_t           st_rdev;
+  int64_t            st_size;
+  int64_t            st_blksize;
+  int64_t            st_blocks;
+  uint64_t           st_atime_;
+  uint64_t           st_atime_nsec_;
+  uint64_t           st_mtime_;
+  uint64_t           st_mtime_nsec_;
+  uint64_t           st_ctime_;
+  uint64_t           st_ctime_nsec_;
+  int64_t            __unused4[3];
+};
+#elif defined(__PPC__)
+struct kernel_stat {
+  unsigned           st_dev;
+  unsigned long      st_ino;      // ino_t
+  unsigned long      st_mode;     // mode_t
+  unsigned short     st_nlink;    // nlink_t
+  unsigned           st_uid;      // uid_t
+  unsigned           st_gid;      // gid_t
+  unsigned           st_rdev;
+  long               st_size;     // off_t
+  unsigned long      st_blksize;
+  unsigned long      st_blocks;
+  unsigned long      st_atime_;
+  unsigned long      st_atime_nsec_;
+  unsigned long      st_mtime_;
+  unsigned long      st_mtime_nsec_;
+  unsigned long      st_ctime_;
+  unsigned long      st_ctime_nsec_;
+  unsigned long      __unused4;
+  unsigned long      __unused5;
+};
+#elif (defined(__mips__) && _MIPS_SIM != _MIPS_SIM_ABI64)
+struct kernel_stat {
+  unsigned           st_dev;
+  int                st_pad1[3];
+  unsigned           st_ino;
+  unsigned           st_mode;
+  unsigned           st_nlink;
+  unsigned           st_uid;
+  unsigned           st_gid;
+  unsigned           st_rdev;
+  int                st_pad2[2];
+  long               st_size;
+  int                st_pad3;
+  long               st_atime_;
+  long               st_atime_nsec_;
+  long               st_mtime_;
+  long               st_mtime_nsec_;
+  long               st_ctime_;
+  long               st_ctime_nsec_;
+  int                st_blksize;
+  int                st_blocks;
+  int                st_pad4[14];
+};
+#elif defined(__aarch64__)
+struct kernel_stat {
+  unsigned long      st_dev;
+  unsigned long      st_ino;
+  unsigned int       st_mode;
+  unsigned int       st_nlink;
+  unsigned int       st_uid;
+  unsigned int       st_gid;
+  unsigned long      st_rdev;
+  unsigned long      __pad1;
+  long               st_size;
+  int                st_blksize;
+  int                __pad2;
+  long               st_blocks;
+  long               st_atime_;
+  unsigned long      st_atime_nsec_;
+  long               st_mtime_;
+  unsigned long      st_mtime_nsec_;
+  long               st_ctime_;
+  unsigned long      st_ctime_nsec_;
+  unsigned int       __unused4;
+  unsigned int       __unused5;
+};
+#elif defined(__s390x__)
+struct kernel_stat {
+  unsigned long      st_dev;
+  unsigned long      st_ino;
+  unsigned long      st_nlink;
+  unsigned int       st_mode;
+  unsigned int       st_uid;
+  unsigned int       st_gid;
+  unsigned int       __pad1;
+  unsigned long      st_rdev;
+  unsigned long      st_size;
+  unsigned long      st_atime_;
+  unsigned long      st_atime_nsec_;
+  unsigned long      st_mtime_;
+  unsigned long      st_mtime_nsec_;
+  unsigned long      st_ctime_;
+  unsigned long      st_ctime_nsec_;
+  unsigned long      st_blksize;
+  long               st_blocks;
+  unsigned long      __unused[3];
+};
+#elif defined(__s390__)
+struct kernel_stat {
+  unsigned short     st_dev;
+  unsigned short     __pad1;
+  unsigned long      st_ino;
+  unsigned short     st_mode;
+  unsigned short     st_nlink;
+  unsigned short     st_uid;
+  unsigned short     st_gid;
+  unsigned short     st_rdev;
+  unsigned short     __pad2;
+  unsigned long      st_size;
+  unsigned long      st_blksize;
+  unsigned long      st_blocks;
+  unsigned long      st_atime_;
+  unsigned long      st_atime_nsec_;
+  unsigned long      st_mtime_;
+  unsigned long      st_mtime_nsec_;
+  unsigned long      st_ctime_;
+  unsigned long      st_ctime_nsec_;
+  unsigned long      __unused4;
+  unsigned long      __unused5;
+};
+#endif
+
+/* include/asm-{arm,aarch64,i386,mips,x86_64,ppc,s390}/statfs.h              */
+#ifdef __mips__
+#if _MIPS_SIM != _MIPS_SIM_ABI64
+struct kernel_statfs64 {
+  unsigned long      f_type;
+  unsigned long      f_bsize;
+  unsigned long      f_frsize;
+  unsigned long      __pad;
+  unsigned long long f_blocks;
+  unsigned long long f_bfree;
+  unsigned long long f_files;
+  unsigned long long f_ffree;
+  unsigned long long f_bavail;
+  struct { int val[2]; } f_fsid;
+  unsigned long      f_namelen;
+  unsigned long      f_spare[6];
+};
+#endif
+#elif defined(__s390__)
+/* See also arch/s390/include/asm/compat.h                                   */
+struct kernel_statfs64 {
+  unsigned int       f_type;
+  unsigned int       f_bsize;
+  unsigned long long f_blocks;
+  unsigned long long f_bfree;
+  unsigned long long f_bavail;
+  unsigned long long f_files;
+  unsigned long long f_ffree;
+  struct { int val[2]; } f_fsid;
+  unsigned int       f_namelen;
+  unsigned int       f_frsize;
+  unsigned int       f_flags;
+  unsigned int       f_spare[4];
+};
+#elif !defined(__x86_64__)
+struct kernel_statfs64 {
+  unsigned long      f_type;
+  unsigned long      f_bsize;
+  unsigned long long f_blocks;
+  unsigned long long f_bfree;
+  unsigned long long f_bavail;
+  unsigned long long f_files;
+  unsigned long long f_ffree;
+  struct { int val[2]; } f_fsid;
+  unsigned long      f_namelen;
+  unsigned long      f_frsize;
+  unsigned long      f_spare[5];
+};
+#endif
+
+/* include/asm-{arm,i386,mips,x86_64,ppc,generic,s390}/statfs.h              */
+#ifdef __mips__
+struct kernel_statfs {
+  long               f_type;
+  long               f_bsize;
+  long               f_frsize;
+  long               f_blocks;
+  long               f_bfree;
+  long               f_files;
+  long               f_ffree;
+  long               f_bavail;
+  struct { int val[2]; } f_fsid;
+  long               f_namelen;
+  long               f_spare[6];
+};
+#elif defined(__x86_64__)
+struct kernel_statfs {
+  /* x86_64 actually defines all these fields as signed, whereas all other  */
+  /* platforms define them as unsigned. Leaving them at unsigned should not */
+  /* cause any problems. Make sure these are 64-bit even on x32.            */
+  uint64_t           f_type;
+  uint64_t           f_bsize;
+  uint64_t           f_blocks;
+  uint64_t           f_bfree;
+  uint64_t           f_bavail;
+  uint64_t           f_files;
+  uint64_t           f_ffree;
+  struct { int val[2]; } f_fsid;
+  uint64_t           f_namelen;
+  uint64_t           f_frsize;
+  uint64_t           f_spare[5];
+};
+#elif defined(__s390__)
+struct kernel_statfs {
+  unsigned int       f_type;
+  unsigned int       f_bsize;
+  unsigned long      f_blocks;
+  unsigned long      f_bfree;
+  unsigned long      f_bavail;
+  unsigned long      f_files;
+  unsigned long      f_ffree;
+  struct { int val[2]; } f_fsid;
+  unsigned int       f_namelen;
+  unsigned int       f_frsize;
+  unsigned int       f_flags;
+  unsigned int       f_spare[4];
+};
+#else
+struct kernel_statfs {
+  unsigned long      f_type;
+  unsigned long      f_bsize;
+  unsigned long      f_blocks;
+  unsigned long      f_bfree;
+  unsigned long      f_bavail;
+  unsigned long      f_files;
+  unsigned long      f_ffree;
+  struct { int val[2]; } f_fsid;
+  unsigned long      f_namelen;
+  unsigned long      f_frsize;
+  unsigned long      f_spare[5];
+};
+#endif
+
+
+/* Definitions missing from the standard header files                        */
+#ifndef O_DIRECTORY
+#if defined(__ARM_ARCH_3__) || defined(__ARM_EABI__) || defined(__aarch64__)
+#define O_DIRECTORY             0040000
+#else
+#define O_DIRECTORY             0200000
+#endif
+#endif
+#ifndef NT_PRXFPREG
+#define NT_PRXFPREG             0x46e62b7f
+#endif
+#ifndef PTRACE_GETFPXREGS
+#define PTRACE_GETFPXREGS       ((enum __ptrace_request)18)
+#endif
+#ifndef PR_GET_DUMPABLE
+#define PR_GET_DUMPABLE         3
+#endif
+#ifndef PR_SET_DUMPABLE
+#define PR_SET_DUMPABLE         4
+#endif
+#ifndef PR_GET_SECCOMP
+#define PR_GET_SECCOMP          21
+#endif
+#ifndef PR_SET_SECCOMP
+#define PR_SET_SECCOMP          22
+#endif
+#ifndef AT_FDCWD
+#define AT_FDCWD                (-100)
+#endif
+#ifndef AT_SYMLINK_NOFOLLOW
+#define AT_SYMLINK_NOFOLLOW     0x100
+#endif
+#ifndef AT_REMOVEDIR
+#define AT_REMOVEDIR            0x200
+#endif
+#ifndef MREMAP_FIXED
+#define MREMAP_FIXED            2
+#endif
+#ifndef SA_RESTORER
+#define SA_RESTORER             0x04000000
+#endif
+#ifndef CPUCLOCK_PROF
+#define CPUCLOCK_PROF           0
+#endif
+#ifndef CPUCLOCK_VIRT
+#define CPUCLOCK_VIRT           1
+#endif
+#ifndef CPUCLOCK_SCHED
+#define CPUCLOCK_SCHED          2
+#endif
+#ifndef CPUCLOCK_PERTHREAD_MASK
+#define CPUCLOCK_PERTHREAD_MASK 4
+#endif
+#ifndef MAKE_PROCESS_CPUCLOCK
+#define MAKE_PROCESS_CPUCLOCK(pid, clock)                                     \
+        ((int)(~(unsigned)(pid) << 3) | (int)(clock))
+#endif
+#ifndef MAKE_THREAD_CPUCLOCK
+#define MAKE_THREAD_CPUCLOCK(tid, clock)                                      \
+        ((int)(~(unsigned)(tid) << 3) |                                       \
+         (int)((clock) | CPUCLOCK_PERTHREAD_MASK))
+#endif
+
+#ifndef FUTEX_WAIT
+#define FUTEX_WAIT                0
+#endif
+#ifndef FUTEX_WAKE
+#define FUTEX_WAKE                1
+#endif
+#ifndef FUTEX_FD
+#define FUTEX_FD                  2
+#endif
+#ifndef FUTEX_REQUEUE
+#define FUTEX_REQUEUE             3
+#endif
+#ifndef FUTEX_CMP_REQUEUE
+#define FUTEX_CMP_REQUEUE         4
+#endif
+#ifndef FUTEX_WAKE_OP
+#define FUTEX_WAKE_OP             5
+#endif
+#ifndef FUTEX_LOCK_PI
+#define FUTEX_LOCK_PI             6
+#endif
+#ifndef FUTEX_UNLOCK_PI
+#define FUTEX_UNLOCK_PI           7
+#endif
+#ifndef FUTEX_TRYLOCK_PI
+#define FUTEX_TRYLOCK_PI          8
+#endif
+#ifndef FUTEX_PRIVATE_FLAG
+#define FUTEX_PRIVATE_FLAG        128
+#endif
+#ifndef FUTEX_CMD_MASK
+#define FUTEX_CMD_MASK            ~FUTEX_PRIVATE_FLAG
+#endif
+#ifndef FUTEX_WAIT_PRIVATE
+#define FUTEX_WAIT_PRIVATE        (FUTEX_WAIT | FUTEX_PRIVATE_FLAG)
+#endif
+#ifndef FUTEX_WAKE_PRIVATE
+#define FUTEX_WAKE_PRIVATE        (FUTEX_WAKE | FUTEX_PRIVATE_FLAG)
+#endif
+#ifndef FUTEX_REQUEUE_PRIVATE
+#define FUTEX_REQUEUE_PRIVATE     (FUTEX_REQUEUE | FUTEX_PRIVATE_FLAG)
+#endif
+#ifndef FUTEX_CMP_REQUEUE_PRIVATE
+#define FUTEX_CMP_REQUEUE_PRIVATE (FUTEX_CMP_REQUEUE | FUTEX_PRIVATE_FLAG)
+#endif
+#ifndef FUTEX_WAKE_OP_PRIVATE
+#define FUTEX_WAKE_OP_PRIVATE     (FUTEX_WAKE_OP | FUTEX_PRIVATE_FLAG)
+#endif
+#ifndef FUTEX_LOCK_PI_PRIVATE
+#define FUTEX_LOCK_PI_PRIVATE     (FUTEX_LOCK_PI | FUTEX_PRIVATE_FLAG)
+#endif
+#ifndef FUTEX_UNLOCK_PI_PRIVATE
+#define FUTEX_UNLOCK_PI_PRIVATE   (FUTEX_UNLOCK_PI | FUTEX_PRIVATE_FLAG)
+#endif
+#ifndef FUTEX_TRYLOCK_PI_PRIVATE
+#define FUTEX_TRYLOCK_PI_PRIVATE  (FUTEX_TRYLOCK_PI | FUTEX_PRIVATE_FLAG)
+#endif
+
+
+#if defined(__x86_64__)
+#ifndef ARCH_SET_GS
+#define ARCH_SET_GS             0x1001
+#endif
+#ifndef ARCH_GET_GS
+#define ARCH_GET_GS             0x1004
+#endif
+#endif
+
+#if defined(__i386__)
+#ifndef __NR_quotactl
+#define __NR_quotactl           131
+#endif
+#ifndef __NR_setresuid
+#define __NR_setresuid          164
+#define __NR_getresuid          165
+#define __NR_setresgid          170
+#define __NR_getresgid          171
+#endif
+#ifndef __NR_rt_sigaction
+#define __NR_rt_sigreturn       173
+#define __NR_rt_sigaction       174
+#define __NR_rt_sigprocmask     175
+#define __NR_rt_sigpending      176
+#define __NR_rt_sigsuspend      179
+#endif
+#ifndef __NR_pread64
+#define __NR_pread64            180
+#endif
+#ifndef __NR_pwrite64
+#define __NR_pwrite64           181
+#endif
+#ifndef __NR_ugetrlimit
+#define __NR_ugetrlimit         191
+#endif
+#ifndef __NR_stat64
+#define __NR_stat64             195
+#endif
+#ifndef __NR_fstat64
+#define __NR_fstat64            197
+#endif
+#ifndef __NR_setresuid32
+#define __NR_setresuid32        208
+#define __NR_getresuid32        209
+#define __NR_setresgid32        210
+#define __NR_getresgid32        211
+#endif
+#ifndef __NR_setfsuid32
+#define __NR_setfsuid32         215
+#define __NR_setfsgid32         216
+#endif
+#ifndef __NR_getdents64
+#define __NR_getdents64         220
+#endif
+#ifndef __NR_gettid
+#define __NR_gettid             224
+#endif
+#ifndef __NR_readahead
+#define __NR_readahead          225
+#endif
+#ifndef __NR_setxattr
+#define __NR_setxattr           226
+#endif
+#ifndef __NR_lsetxattr
+#define __NR_lsetxattr          227
+#endif
+#ifndef __NR_getxattr
+#define __NR_getxattr           229
+#endif
+#ifndef __NR_lgetxattr
+#define __NR_lgetxattr          230
+#endif
+#ifndef __NR_listxattr
+#define __NR_listxattr          232
+#endif
+#ifndef __NR_llistxattr
+#define __NR_llistxattr         233
+#endif
+#ifndef __NR_tkill
+#define __NR_tkill              238
+#endif
+#ifndef __NR_futex
+#define __NR_futex              240
+#endif
+#ifndef __NR_sched_setaffinity
+#define __NR_sched_setaffinity  241
+#define __NR_sched_getaffinity  242
+#endif
+#ifndef __NR_set_tid_address
+#define __NR_set_tid_address    258
+#endif
+#ifndef __NR_clock_gettime
+#define __NR_clock_gettime      265
+#endif
+#ifndef __NR_clock_getres
+#define __NR_clock_getres       266
+#endif
+#ifndef __NR_statfs64
+#define __NR_statfs64           268
+#endif
+#ifndef __NR_fstatfs64
+#define __NR_fstatfs64          269
+#endif
+#ifndef __NR_fadvise64_64
+#define __NR_fadvise64_64       272
+#endif
+#ifndef __NR_ioprio_set
+#define __NR_ioprio_set         289
+#endif
+#ifndef __NR_ioprio_get
+#define __NR_ioprio_get         290
+#endif
+#ifndef __NR_openat
+#define __NR_openat             295
+#endif
+#ifndef __NR_fstatat64
+#define __NR_fstatat64          300
+#endif
+#ifndef __NR_unlinkat
+#define __NR_unlinkat           301
+#endif
+#ifndef __NR_move_pages
+#define __NR_move_pages         317
+#endif
+#ifndef __NR_getcpu
+#define __NR_getcpu             318
+#endif
+#ifndef __NR_fallocate
+#define __NR_fallocate          324
+#endif
+/* End of i386 definitions                                                   */
+#elif defined(__ARM_ARCH_3__) || defined(__ARM_EABI__)
+#ifndef __NR_setresuid
+#define __NR_setresuid          (__NR_SYSCALL_BASE + 164)
+#define __NR_getresuid          (__NR_SYSCALL_BASE + 165)
+#define __NR_setresgid          (__NR_SYSCALL_BASE + 170)
+#define __NR_getresgid          (__NR_SYSCALL_BASE + 171)
+#endif
+#ifndef __NR_rt_sigaction
+#define __NR_rt_sigreturn       (__NR_SYSCALL_BASE + 173)
+#define __NR_rt_sigaction       (__NR_SYSCALL_BASE + 174)
+#define __NR_rt_sigprocmask     (__NR_SYSCALL_BASE + 175)
+#define __NR_rt_sigpending      (__NR_SYSCALL_BASE + 176)
+#define __NR_rt_sigsuspend      (__NR_SYSCALL_BASE + 179)
+#endif
+#ifndef __NR_pread64
+#define __NR_pread64            (__NR_SYSCALL_BASE + 180)
+#endif
+#ifndef __NR_pwrite64
+#define __NR_pwrite64           (__NR_SYSCALL_BASE + 181)
+#endif
+#ifndef __NR_ugetrlimit
+#define __NR_ugetrlimit         (__NR_SYSCALL_BASE + 191)
+#endif
+#ifndef __NR_stat64
+#define __NR_stat64             (__NR_SYSCALL_BASE + 195)
+#endif
+#ifndef __NR_fstat64
+#define __NR_fstat64            (__NR_SYSCALL_BASE + 197)
+#endif
+#ifndef __NR_setresuid32
+#define __NR_setresuid32        (__NR_SYSCALL_BASE + 208)
+#define __NR_getresuid32        (__NR_SYSCALL_BASE + 209)
+#define __NR_setresgid32        (__NR_SYSCALL_BASE + 210)
+#define __NR_getresgid32        (__NR_SYSCALL_BASE + 211)
+#endif
+#ifndef __NR_setfsuid32
+#define __NR_setfsuid32         (__NR_SYSCALL_BASE + 215)
+#define __NR_setfsgid32         (__NR_SYSCALL_BASE + 216)
+#endif
+#ifndef __NR_getdents64
+#define __NR_getdents64         (__NR_SYSCALL_BASE + 217)
+#endif
+#ifndef __NR_gettid
+#define __NR_gettid             (__NR_SYSCALL_BASE + 224)
+#endif
+#ifndef __NR_readahead
+#define __NR_readahead          (__NR_SYSCALL_BASE + 225)
+#endif
+#ifndef __NR_setxattr
+#define __NR_setxattr           (__NR_SYSCALL_BASE + 226)
+#endif
+#ifndef __NR_lsetxattr
+#define __NR_lsetxattr          (__NR_SYSCALL_BASE + 227)
+#endif
+#ifndef __NR_getxattr
+#define __NR_getxattr           (__NR_SYSCALL_BASE + 229)
+#endif
+#ifndef __NR_lgetxattr
+#define __NR_lgetxattr          (__NR_SYSCALL_BASE + 230)
+#endif
+#ifndef __NR_listxattr
+#define __NR_listxattr          (__NR_SYSCALL_BASE + 232)
+#endif
+#ifndef __NR_llistxattr
+#define __NR_llistxattr         (__NR_SYSCALL_BASE + 233)
+#endif
+#ifndef __NR_tkill
+#define __NR_tkill              (__NR_SYSCALL_BASE + 238)
+#endif
+#ifndef __NR_futex
+#define __NR_futex              (__NR_SYSCALL_BASE + 240)
+#endif
+#ifndef __NR_sched_setaffinity
+#define __NR_sched_setaffinity  (__NR_SYSCALL_BASE + 241)
+#define __NR_sched_getaffinity  (__NR_SYSCALL_BASE + 242)
+#endif
+#ifndef __NR_set_tid_address
+#define __NR_set_tid_address    (__NR_SYSCALL_BASE + 256)
+#endif
+#ifndef __NR_clock_gettime
+#define __NR_clock_gettime      (__NR_SYSCALL_BASE + 263)
+#endif
+#ifndef __NR_clock_getres
+#define __NR_clock_getres       (__NR_SYSCALL_BASE + 264)
+#endif
+#ifndef __NR_statfs64
+#define __NR_statfs64           (__NR_SYSCALL_BASE + 266)
+#endif
+#ifndef __NR_fstatfs64
+#define __NR_fstatfs64          (__NR_SYSCALL_BASE + 267)
+#endif
+#ifndef __NR_ioprio_set
+#define __NR_ioprio_set         (__NR_SYSCALL_BASE + 314)
+#endif
+#ifndef __NR_ioprio_get
+#define __NR_ioprio_get         (__NR_SYSCALL_BASE + 315)
+#endif
+#ifndef __NR_move_pages
+#define __NR_move_pages         (__NR_SYSCALL_BASE + 344)
+#endif
+#ifndef __NR_getcpu
+#define __NR_getcpu             (__NR_SYSCALL_BASE + 345)
+#endif
+/* End of ARM 3/EABI definitions                                             */
+#elif defined(__aarch64__)
+#ifndef __NR_setxattr
+#define __NR_setxattr             5
+#endif
+#ifndef __NR_lsetxattr
+#define __NR_lsetxattr            6
+#endif
+#ifndef __NR_getxattr
+#define __NR_getxattr             8
+#endif
+#ifndef __NR_lgetxattr
+#define __NR_lgetxattr            9
+#endif
+#ifndef __NR_listxattr
+#define __NR_listxattr           11
+#endif
+#ifndef __NR_llistxattr
+#define __NR_llistxattr          12
+#endif
+#ifndef __NR_ioprio_set
+#define __NR_ioprio_set          30
+#endif
+#ifndef __NR_ioprio_get
+#define __NR_ioprio_get          31
+#endif
+#ifndef __NR_unlinkat
+#define __NR_unlinkat            35
+#endif
+#ifndef __NR_fallocate
+#define __NR_fallocate           47
+#endif
+#ifndef __NR_openat
+#define __NR_openat              56
+#endif
+#ifndef __NR_quotactl
+#define __NR_quotactl            60
+#endif
+#ifndef __NR_getdents64
+#define __NR_getdents64          61
+#endif
+#ifndef __NR_getdents
+// when getdents is not available, getdents64 is used for both.
+#define __NR_getdents            __NR_getdents64
+#endif
+#ifndef __NR_pread64
+#define __NR_pread64             67
+#endif
+#ifndef __NR_pwrite64
+#define __NR_pwrite64            68
+#endif
+#ifndef __NR_ppoll
+#define __NR_ppoll               73
+#endif
+#ifndef __NR_readlinkat
+#define __NR_readlinkat          78
+#endif
+#ifndef __NR_newfstatat
+#define __NR_newfstatat          79
+#endif
+#ifndef __NR_set_tid_address
+#define __NR_set_tid_address     96
+#endif
+#ifndef __NR_futex
+#define __NR_futex               98
+#endif
+#ifndef __NR_clock_gettime
+#define __NR_clock_gettime      113
+#endif
+#ifndef __NR_clock_getres
+#define __NR_clock_getres       114
+#endif
+#ifndef __NR_sched_setaffinity
+#define __NR_sched_setaffinity  122
+#define __NR_sched_getaffinity  123
+#endif
+#ifndef __NR_tkill
+#define __NR_tkill              130
+#endif
+#ifndef __NR_setresuid
+#define __NR_setresuid          147
+#define __NR_getresuid          148
+#define __NR_setresgid          149
+#define __NR_getresgid          150
+#endif
+#ifndef __NR_gettid
+#define __NR_gettid             178
+#endif
+#ifndef __NR_readahead
+#define __NR_readahead          213
+#endif
+#ifndef __NR_fadvise64
+#define __NR_fadvise64          223
+#endif
+#ifndef __NR_move_pages
+#define __NR_move_pages         239
+#endif
+/* End of aarch64 definitions                                                */
+#elif defined(__x86_64__)
+#ifndef __NR_pread64
+#define __NR_pread64             17
+#endif
+#ifndef __NR_pwrite64
+#define __NR_pwrite64            18
+#endif
+#ifndef __NR_setresuid
+#define __NR_setresuid          117
+#define __NR_getresuid          118
+#define __NR_setresgid          119
+#define __NR_getresgid          120
+#endif
+#ifndef __NR_quotactl
+#define __NR_quotactl           179
+#endif
+#ifndef __NR_gettid
+#define __NR_gettid             186
+#endif
+#ifndef __NR_readahead
+#define __NR_readahead          187
+#endif
+#ifndef __NR_setxattr
+#define __NR_setxattr           188
+#endif
+#ifndef __NR_lsetxattr
+#define __NR_lsetxattr          189
+#endif
+#ifndef __NR_getxattr
+#define __NR_getxattr           191
+#endif
+#ifndef __NR_lgetxattr
+#define __NR_lgetxattr          192
+#endif
+#ifndef __NR_listxattr
+#define __NR_listxattr          194
+#endif
+#ifndef __NR_llistxattr
+#define __NR_llistxattr         195
+#endif
+#ifndef __NR_tkill
+#define __NR_tkill              200
+#endif
+#ifndef __NR_futex
+#define __NR_futex              202
+#endif
+#ifndef __NR_sched_setaffinity
+#define __NR_sched_setaffinity  203
+#define __NR_sched_getaffinity  204
+#endif
+#ifndef __NR_getdents64
+#define __NR_getdents64         217
+#endif
+#ifndef __NR_getdents
+// when getdents is not available, getdents64 is used for both.
+#define __NR_getdents           __NR_getdents64
+#endif
+#ifndef __NR_set_tid_address
+#define __NR_set_tid_address    218
+#endif
+#ifndef __NR_fadvise64
+#define __NR_fadvise64          221
+#endif
+#ifndef __NR_clock_gettime
+#define __NR_clock_gettime      228
+#endif
+#ifndef __NR_clock_getres
+#define __NR_clock_getres       229
+#endif
+#ifndef __NR_ioprio_set
+#define __NR_ioprio_set         251
+#endif
+#ifndef __NR_ioprio_get
+#define __NR_ioprio_get         252
+#endif
+#ifndef __NR_openat
+#define __NR_openat             257
+#endif
+#ifndef __NR_newfstatat
+#define __NR_newfstatat         262
+#endif
+#ifndef __NR_unlinkat
+#define __NR_unlinkat           263
+#endif
+#ifndef __NR_move_pages
+#define __NR_move_pages         279
+#endif
+#ifndef __NR_fallocate
+#define __NR_fallocate          285
+#endif
+/* End of x86-64 definitions                                                 */
+#elif defined(__mips__)
+#if _MIPS_SIM == _MIPS_SIM_ABI32
+#ifndef __NR_setresuid
+#define __NR_setresuid          (__NR_Linux + 185)
+#define __NR_getresuid          (__NR_Linux + 186)
+#define __NR_setresgid          (__NR_Linux + 190)
+#define __NR_getresgid          (__NR_Linux + 191)
+#endif
+#ifndef __NR_rt_sigaction
+#define __NR_rt_sigreturn       (__NR_Linux + 193)
+#define __NR_rt_sigaction       (__NR_Linux + 194)
+#define __NR_rt_sigprocmask     (__NR_Linux + 195)
+#define __NR_rt_sigpending      (__NR_Linux + 196)
+#define __NR_rt_sigsuspend      (__NR_Linux + 199)
+#endif
+#ifndef __NR_pread64
+#define __NR_pread64            (__NR_Linux + 200)
+#endif
+#ifndef __NR_pwrite64
+#define __NR_pwrite64           (__NR_Linux + 201)
+#endif
+#ifndef __NR_stat64
+#define __NR_stat64             (__NR_Linux + 213)
+#endif
+#ifndef __NR_fstat64
+#define __NR_fstat64            (__NR_Linux + 215)
+#endif
+#ifndef __NR_getdents64
+#define __NR_getdents64         (__NR_Linux + 219)
+#endif
+#ifndef __NR_gettid
+#define __NR_gettid             (__NR_Linux + 222)
+#endif
+#ifndef __NR_readahead
+#define __NR_readahead          (__NR_Linux + 223)
+#endif
+#ifndef __NR_setxattr
+#define __NR_setxattr           (__NR_Linux + 224)
+#endif
+#ifndef __NR_lsetxattr
+#define __NR_lsetxattr          (__NR_Linux + 225)
+#endif
+#ifndef __NR_getxattr
+#define __NR_getxattr           (__NR_Linux + 227)
+#endif
+#ifndef __NR_lgetxattr
+#define __NR_lgetxattr          (__NR_Linux + 228)
+#endif
+#ifndef __NR_listxattr
+#define __NR_listxattr          (__NR_Linux + 230)
+#endif
+#ifndef __NR_llistxattr
+#define __NR_llistxattr         (__NR_Linux + 231)
+#endif
+#ifndef __NR_tkill
+#define __NR_tkill              (__NR_Linux + 236)
+#endif
+#ifndef __NR_futex
+#define __NR_futex              (__NR_Linux + 238)
+#endif
+#ifndef __NR_sched_setaffinity
+#define __NR_sched_setaffinity  (__NR_Linux + 239)
+#define __NR_sched_getaffinity  (__NR_Linux + 240)
+#endif
+#ifndef __NR_set_tid_address
+#define __NR_set_tid_address    (__NR_Linux + 252)
+#endif
+#ifndef __NR_statfs64
+#define __NR_statfs64           (__NR_Linux + 255)
+#endif
+#ifndef __NR_fstatfs64
+#define __NR_fstatfs64          (__NR_Linux + 256)
+#endif
+#ifndef __NR_clock_gettime
+#define __NR_clock_gettime      (__NR_Linux + 263)
+#endif
+#ifndef __NR_clock_getres
+#define __NR_clock_getres       (__NR_Linux + 264)
+#endif
+#ifndef __NR_openat
+#define __NR_openat             (__NR_Linux + 288)
+#endif
+#ifndef __NR_fstatat
+#define __NR_fstatat            (__NR_Linux + 293)
+#endif
+#ifndef __NR_unlinkat
+#define __NR_unlinkat           (__NR_Linux + 294)
+#endif
+#ifndef __NR_move_pages
+#define __NR_move_pages         (__NR_Linux + 308)
+#endif
+#ifndef __NR_getcpu
+#define __NR_getcpu             (__NR_Linux + 312)
+#endif
+#ifndef __NR_ioprio_set
+#define __NR_ioprio_set         (__NR_Linux + 314)
+#endif
+#ifndef __NR_ioprio_get
+#define __NR_ioprio_get         (__NR_Linux + 315)
+#endif
+/* End of MIPS (old 32bit API) definitions */
+#elif  _MIPS_SIM == _MIPS_SIM_ABI64
+#ifndef __NR_pread64
+#define __NR_pread64            (__NR_Linux +  16)
+#endif
+#ifndef __NR_pwrite64
+#define __NR_pwrite64           (__NR_Linux +  17)
+#endif
+#ifndef __NR_setresuid
+#define __NR_setresuid          (__NR_Linux + 115)
+#define __NR_getresuid          (__NR_Linux + 116)
+#define __NR_setresgid          (__NR_Linux + 117)
+#define __NR_getresgid          (__NR_Linux + 118)
+#endif
+#ifndef __NR_gettid
+#define __NR_gettid             (__NR_Linux + 178)
+#endif
+#ifndef __NR_readahead
+#define __NR_readahead          (__NR_Linux + 179)
+#endif
+#ifndef __NR_setxattr
+#define __NR_setxattr           (__NR_Linux + 180)
+#endif
+#ifndef __NR_lsetxattr
+#define __NR_lsetxattr          (__NR_Linux + 181)
+#endif
+#ifndef __NR_getxattr
+#define __NR_getxattr           (__NR_Linux + 183)
+#endif
+#ifndef __NR_lgetxattr
+#define __NR_lgetxattr          (__NR_Linux + 184)
+#endif
+#ifndef __NR_listxattr
+#define __NR_listxattr          (__NR_Linux + 186)
+#endif
+#ifndef __NR_llistxattr
+#define __NR_llistxattr         (__NR_Linux + 187)
+#endif
+#ifndef __NR_tkill
+#define __NR_tkill              (__NR_Linux + 192)
+#endif
+#ifndef __NR_futex
+#define __NR_futex              (__NR_Linux + 194)
+#endif
+#ifndef __NR_sched_setaffinity
+#define __NR_sched_setaffinity  (__NR_Linux + 195)
+#define __NR_sched_getaffinity  (__NR_Linux + 196)
+#endif
+#ifndef __NR_set_tid_address
+#define __NR_set_tid_address    (__NR_Linux + 212)
+#endif
+#ifndef __NR_clock_gettime
+#define __NR_clock_gettime      (__NR_Linux + 222)
+#endif
+#ifndef __NR_clock_getres
+#define __NR_clock_getres       (__NR_Linux + 223)
+#endif
+#ifndef __NR_openat
+#define __NR_openat             (__NR_Linux + 247)
+#endif
+#ifndef __NR_fstatat
+#define __NR_fstatat            (__NR_Linux + 252)
+#endif
+#ifndef __NR_unlinkat
+#define __NR_unlinkat           (__NR_Linux + 253)
+#endif
+#ifndef __NR_move_pages
+#define __NR_move_pages         (__NR_Linux + 267)
+#endif
+#ifndef __NR_getcpu
+#define __NR_getcpu             (__NR_Linux + 271)
+#endif
+#ifndef __NR_ioprio_set
+#define __NR_ioprio_set         (__NR_Linux + 273)
+#endif
+#ifndef __NR_ioprio_get
+#define __NR_ioprio_get         (__NR_Linux + 274)
+#endif
+/* End of MIPS (64bit API) definitions */
+#else
+#ifndef __NR_setresuid
+#define __NR_setresuid          (__NR_Linux + 115)
+#define __NR_getresuid          (__NR_Linux + 116)
+#define __NR_setresgid          (__NR_Linux + 117)
+#define __NR_getresgid          (__NR_Linux + 118)
+#endif
+#ifndef __NR_gettid
+#define __NR_gettid             (__NR_Linux + 178)
+#endif
+#ifndef __NR_readahead
+#define __NR_readahead          (__NR_Linux + 179)
+#endif
+#ifndef __NR_setxattr
+#define __NR_setxattr           (__NR_Linux + 180)
+#endif
+#ifndef __NR_lsetxattr
+#define __NR_lsetxattr          (__NR_Linux + 181)
+#endif
+#ifndef __NR_getxattr
+#define __NR_getxattr           (__NR_Linux + 183)
+#endif
+#ifndef __NR_lgetxattr
+#define __NR_lgetxattr          (__NR_Linux + 184)
+#endif
+#ifndef __NR_listxattr
+#define __NR_listxattr          (__NR_Linux + 186)
+#endif
+#ifndef __NR_llistxattr
+#define __NR_llistxattr         (__NR_Linux + 187)
+#endif
+#ifndef __NR_tkill
+#define __NR_tkill              (__NR_Linux + 192)
+#endif
+#ifndef __NR_futex
+#define __NR_futex              (__NR_Linux + 194)
+#endif
+#ifndef __NR_sched_setaffinity
+#define __NR_sched_setaffinity  (__NR_Linux + 195)
+#define __NR_sched_getaffinity  (__NR_Linux + 196)
+#endif
+#ifndef __NR_set_tid_address
+#define __NR_set_tid_address    (__NR_Linux + 213)
+#endif
+#ifndef __NR_statfs64
+#define __NR_statfs64           (__NR_Linux + 217)
+#endif
+#ifndef __NR_fstatfs64
+#define __NR_fstatfs64          (__NR_Linux + 218)
+#endif
+#ifndef __NR_clock_gettime
+#define __NR_clock_gettime      (__NR_Linux + 226)
+#endif
+#ifndef __NR_clock_getres
+#define __NR_clock_getres       (__NR_Linux + 227)
+#endif
+#ifndef __NR_openat
+#define __NR_openat             (__NR_Linux + 251)
+#endif
+#ifndef __NR_fstatat
+#define __NR_fstatat            (__NR_Linux + 256)
+#endif
+#ifndef __NR_unlinkat
+#define __NR_unlinkat           (__NR_Linux + 257)
+#endif
+#ifndef __NR_move_pages
+#define __NR_move_pages         (__NR_Linux + 271)
+#endif
+#ifndef __NR_getcpu
+#define __NR_getcpu             (__NR_Linux + 275)
+#endif
+#ifndef __NR_ioprio_set
+#define __NR_ioprio_set         (__NR_Linux + 277)
+#endif
+#ifndef __NR_ioprio_get
+#define __NR_ioprio_get         (__NR_Linux + 278)
+#endif
+/* End of MIPS (new 32bit API) definitions                                   */
+#endif
+/* End of MIPS definitions                                                   */
+#elif defined(__PPC__)
+#ifndef __NR_setfsuid
+#define __NR_setfsuid           138
+#define __NR_setfsgid           139
+#endif
+#ifndef __NR_setresuid
+#define __NR_setresuid          164
+#define __NR_getresuid          165
+#define __NR_setresgid          169
+#define __NR_getresgid          170
+#endif
+#ifndef __NR_rt_sigaction
+#define __NR_rt_sigreturn       172
+#define __NR_rt_sigaction       173
+#define __NR_rt_sigprocmask     174
+#define __NR_rt_sigpending      175
+#define __NR_rt_sigsuspend      178
+#endif
+#ifndef __NR_pread64
+#define __NR_pread64            179
+#endif
+#ifndef __NR_pwrite64
+#define __NR_pwrite64           180
+#endif
+#ifndef __NR_ugetrlimit
+#define __NR_ugetrlimit         190
+#endif
+#ifndef __NR_readahead
+#define __NR_readahead          191
+#endif
+#ifndef __NR_stat64
+#define __NR_stat64             195
+#endif
+#ifndef __NR_fstat64
+#define __NR_fstat64            197
+#endif
+#ifndef __NR_getdents64
+#define __NR_getdents64         202
+#endif
+#ifndef __NR_gettid
+#define __NR_gettid             207
+#endif
+#ifndef __NR_tkill
+#define __NR_tkill              208
+#endif
+#ifndef __NR_setxattr
+#define __NR_setxattr           209
+#endif
+#ifndef __NR_lsetxattr
+#define __NR_lsetxattr          210
+#endif
+#ifndef __NR_getxattr
+#define __NR_getxattr           212
+#endif
+#ifndef __NR_lgetxattr
+#define __NR_lgetxattr          213
+#endif
+#ifndef __NR_listxattr
+#define __NR_listxattr          215
+#endif
+#ifndef __NR_llistxattr
+#define __NR_llistxattr         216
+#endif
+#ifndef __NR_futex
+#define __NR_futex              221
+#endif
+#ifndef __NR_sched_setaffinity
+#define __NR_sched_setaffinity  222
+#define __NR_sched_getaffinity  223
+#endif
+#ifndef __NR_set_tid_address
+#define __NR_set_tid_address    232
+#endif
+#ifndef __NR_clock_gettime
+#define __NR_clock_gettime      246
+#endif
+#ifndef __NR_clock_getres
+#define __NR_clock_getres       247
+#endif
+#ifndef __NR_statfs64
+#define __NR_statfs64           252
+#endif
+#ifndef __NR_fstatfs64
+#define __NR_fstatfs64          253
+#endif
+#ifndef __NR_fadvise64_64
+#define __NR_fadvise64_64       254
+#endif
+#ifndef __NR_ioprio_set
+#define __NR_ioprio_set         273
+#endif
+#ifndef __NR_ioprio_get
+#define __NR_ioprio_get         274
+#endif
+#ifndef __NR_openat
+#define __NR_openat             286
+#endif
+#ifndef __NR_fstatat64
+#define __NR_fstatat64          291
+#endif
+#ifndef __NR_unlinkat
+#define __NR_unlinkat           292
+#endif
+#ifndef __NR_move_pages
+#define __NR_move_pages         301
+#endif
+#ifndef __NR_getcpu
+#define __NR_getcpu             302
+#endif
+/* End of powerpc defininitions                                              */
+#elif defined(__s390__)
+#ifndef __NR_quotactl
+#define __NR_quotactl           131
+#endif
+#ifndef __NR_rt_sigreturn
+#define __NR_rt_sigreturn       173
+#endif
+#ifndef __NR_rt_sigaction
+#define __NR_rt_sigaction       174
+#endif
+#ifndef __NR_rt_sigprocmask
+#define __NR_rt_sigprocmask     175
+#endif
+#ifndef __NR_rt_sigpending
+#define __NR_rt_sigpending      176
+#endif
+#ifndef __NR_rt_sigsuspend
+#define __NR_rt_sigsuspend      179
+#endif
+#ifndef __NR_pread64
+#define __NR_pread64            180
+#endif
+#ifndef __NR_pwrite64
+#define __NR_pwrite64           181
+#endif
+#ifndef __NR_getdents64
+#define __NR_getdents64         220
+#endif
+#ifndef __NR_readahead
+#define __NR_readahead          222
+#endif
+#ifndef __NR_setxattr
+#define __NR_setxattr           224
+#endif
+#ifndef __NR_lsetxattr
+#define __NR_lsetxattr          225
+#endif
+#ifndef __NR_getxattr
+#define __NR_getxattr           227
+#endif
+#ifndef __NR_lgetxattr
+#define __NR_lgetxattr          228
+#endif
+#ifndef __NR_listxattr
+#define __NR_listxattr          230
+#endif
+#ifndef __NR_llistxattr
+#define __NR_llistxattr         231
+#endif
+#ifndef __NR_gettid
+#define __NR_gettid             236
+#endif
+#ifndef __NR_tkill
+#define __NR_tkill              237
+#endif
+#ifndef __NR_futex
+#define __NR_futex              238
+#endif
+#ifndef __NR_sched_setaffinity
+#define __NR_sched_setaffinity  239
+#endif
+#ifndef __NR_sched_getaffinity
+#define __NR_sched_getaffinity  240
+#endif
+#ifndef __NR_set_tid_address
+#define __NR_set_tid_address    252
+#endif
+#ifndef __NR_clock_gettime
+#define __NR_clock_gettime      260
+#endif
+#ifndef __NR_clock_getres
+#define __NR_clock_getres       261
+#endif
+#ifndef __NR_statfs64
+#define __NR_statfs64           265
+#endif
+#ifndef __NR_fstatfs64
+#define __NR_fstatfs64          266
+#endif
+#ifndef __NR_ioprio_set
+#define __NR_ioprio_set         282
+#endif
+#ifndef __NR_ioprio_get
+#define __NR_ioprio_get         283
+#endif
+#ifndef __NR_openat
+#define __NR_openat             288
+#endif
+#ifndef __NR_unlinkat
+#define __NR_unlinkat           294
+#endif
+#ifndef __NR_move_pages
+#define __NR_move_pages         310
+#endif
+#ifndef __NR_getcpu
+#define __NR_getcpu             311
+#endif
+#ifndef __NR_fallocate
+#define __NR_fallocate          314
+#endif
+/* Some syscalls are named/numbered differently between s390 and s390x. */
+#ifdef __s390x__
+# ifndef __NR_getrlimit
+# define __NR_getrlimit          191
+# endif
+# ifndef __NR_setresuid
+# define __NR_setresuid          208
+# endif
+# ifndef __NR_getresuid
+# define __NR_getresuid          209
+# endif
+# ifndef __NR_setresgid
+# define __NR_setresgid          210
+# endif
+# ifndef __NR_getresgid
+# define __NR_getresgid          211
+# endif
+# ifndef __NR_setfsuid
+# define __NR_setfsuid           215
+# endif
+# ifndef __NR_setfsgid
+# define __NR_setfsgid           216
+# endif
+# ifndef __NR_fadvise64
+# define __NR_fadvise64          253
+# endif
+# ifndef __NR_newfstatat
+# define __NR_newfstatat         293
+# endif
+#else /* __s390x__ */
+# ifndef __NR_getrlimit
+# define __NR_getrlimit          76
+# endif
+# ifndef __NR_setfsuid
+# define __NR_setfsuid           138
+# endif
+# ifndef __NR_setfsgid
+# define __NR_setfsgid           139
+# endif
+# ifndef __NR_setresuid
+# define __NR_setresuid          164
+# endif
+# ifndef __NR_getresuid
+# define __NR_getresuid          165
+# endif
+# ifndef __NR_setresgid
+# define __NR_setresgid          170
+# endif
+# ifndef __NR_getresgid
+# define __NR_getresgid          171
+# endif
+# ifndef __NR_ugetrlimit
+# define __NR_ugetrlimit         191
+# endif
+# ifndef __NR_mmap2
+# define __NR_mmap2              192
+# endif
+# ifndef __NR_setresuid32
+# define __NR_setresuid32        208
+# endif
+# ifndef __NR_getresuid32
+# define __NR_getresuid32        209
+# endif
+# ifndef __NR_setresgid32
+# define __NR_setresgid32        210
+# endif
+# ifndef __NR_getresgid32
+# define __NR_getresgid32        211
+# endif
+# ifndef __NR_setfsuid32
+# define __NR_setfsuid32         215
+# endif
+# ifndef __NR_setfsgid32
+# define __NR_setfsgid32         216
+# endif
+# ifndef __NR_fadvise64_64
+# define __NR_fadvise64_64       264
+# endif
+# ifndef __NR_fstatat64
+# define __NR_fstatat64          293
+# endif
+#endif /* __s390__ */
+/* End of s390/s390x definitions                                             */
+#endif
+
+
+/* After forking, we must make sure to only call system calls.               */
+#if defined(__BOUNDED_POINTERS__)
+  #error "Need to port invocations of syscalls for bounded ptrs"
+#else
+  /* The core dumper and the thread lister get executed after threads
+   * have been suspended. As a consequence, we cannot call any functions
+   * that acquire locks. Unfortunately, libc wraps most system calls
+   * (e.g. in order to implement pthread_atfork, and to make calls
+   * cancellable), which means we cannot call these functions. Instead,
+   * we have to call syscall() directly.
+   */
+  #undef LSS_ERRNO
+  #ifdef SYS_ERRNO
+    /* Allow the including file to override the location of errno. This can
+     * be useful when using clone() with the CLONE_VM option.
+     */
+    #define LSS_ERRNO SYS_ERRNO
+  #else
+    #define LSS_ERRNO errno
+  #endif
+
+  #undef LSS_INLINE
+  #ifdef SYS_INLINE
+    #define LSS_INLINE SYS_INLINE
+  #else
+    #define LSS_INLINE static inline
+  #endif
+
+  /* Allow the including file to override the prefix used for all new
+   * system calls. By default, it will be set to "sys_".
+   */
+  #undef LSS_NAME
+  #ifndef SYS_PREFIX
+    #define LSS_NAME(name) sys_##name
+  #elif defined(SYS_PREFIX) && SYS_PREFIX < 0
+    #define LSS_NAME(name) name
+  #elif defined(SYS_PREFIX) && SYS_PREFIX == 0
+    #define LSS_NAME(name) sys0_##name
+  #elif defined(SYS_PREFIX) && SYS_PREFIX == 1
+    #define LSS_NAME(name) sys1_##name
+  #elif defined(SYS_PREFIX) && SYS_PREFIX == 2
+    #define LSS_NAME(name) sys2_##name
+  #elif defined(SYS_PREFIX) && SYS_PREFIX == 3
+    #define LSS_NAME(name) sys3_##name
+  #elif defined(SYS_PREFIX) && SYS_PREFIX == 4
+    #define LSS_NAME(name) sys4_##name
+  #elif defined(SYS_PREFIX) && SYS_PREFIX == 5
+    #define LSS_NAME(name) sys5_##name
+  #elif defined(SYS_PREFIX) && SYS_PREFIX == 6
+    #define LSS_NAME(name) sys6_##name
+  #elif defined(SYS_PREFIX) && SYS_PREFIX == 7
+    #define LSS_NAME(name) sys7_##name
+  #elif defined(SYS_PREFIX) && SYS_PREFIX == 8
+    #define LSS_NAME(name) sys8_##name
+  #elif defined(SYS_PREFIX) && SYS_PREFIX == 9
+    #define LSS_NAME(name) sys9_##name
+  #endif
+
+  #undef  LSS_RETURN
+  #if (defined(__i386__) || defined(__x86_64__) || defined(__ARM_ARCH_3__) \
+       || defined(__ARM_EABI__) || defined(__aarch64__) || defined(__s390__))
+  /* Failing system calls return a negative result in the range of
+   * -1..-4095. These are "errno" values with the sign inverted.
+   */
+  #define LSS_RETURN(type, res)                                               \
+    do {                                                                      \
+      if ((unsigned long)(res) >= (unsigned long)(-4095)) {                   \
+        LSS_ERRNO = -(res);                                                   \
+        res = -1;                                                             \
+      }                                                                       \
+      return (type) (res);                                                    \
+    } while (0)
+  #elif defined(__mips__)
+  /* On MIPS, failing system calls return -1, and set errno in a
+   * separate CPU register.
+   */
+  #define LSS_RETURN(type, res, err)                                          \
+    do {                                                                      \
+      if (err) {                                                              \
+        unsigned long __errnovalue = (res);                                   \
+        LSS_ERRNO = __errnovalue;                                             \
+        res = -1;                                                             \
+      }                                                                       \
+      return (type) (res);                                                    \
+    } while (0)
+  #elif defined(__PPC__)
+  /* On PPC, failing system calls return -1, and set errno in a
+   * separate CPU register. See linux/unistd.h.
+   */
+  #define LSS_RETURN(type, res, err)                                          \
+   do {                                                                       \
+     if (err & 0x10000000 ) {                                                 \
+       LSS_ERRNO = (res);                                                     \
+       res = -1;                                                              \
+     }                                                                        \
+     return (type) (res);                                                     \
+   } while (0)
+  #endif
+  #if defined(__i386__)
+    /* In PIC mode (e.g. when building shared libraries), gcc for i386
+     * reserves ebx. Unfortunately, most distribution ship with implementations
+     * of _syscallX() which clobber ebx.
+     * Also, most definitions of _syscallX() neglect to mark "memory" as being
+     * clobbered. This causes problems with compilers, that do a better job
+     * at optimizing across __asm__ calls.
+     * So, we just have to redefine all of the _syscallX() macros.
+     */
+    #undef LSS_ENTRYPOINT
+    #ifdef SYS_SYSCALL_ENTRYPOINT
+    static inline void (**LSS_NAME(get_syscall_entrypoint)(void))(void) {
+      void (**entrypoint)(void);
+      asm volatile(".bss\n"
+                   ".align 8\n"
+                   ".globl " SYS_SYSCALL_ENTRYPOINT "\n"
+                   ".common " SYS_SYSCALL_ENTRYPOINT ",8,8\n"
+                   ".previous\n"
+                   /* This logically does 'lea "SYS_SYSCALL_ENTRYPOINT", %0' */
+                   "call 0f\n"
+                 "0:pop  %0\n"
+                   "add  $_GLOBAL_OFFSET_TABLE_+[.-0b], %0\n"
+                   "mov  " SYS_SYSCALL_ENTRYPOINT "@GOT(%0), %0\n"
+                   : "=r"(entrypoint));
+      return entrypoint;
+    }
+
+    #define LSS_ENTRYPOINT ".bss\n"                                           \
+                           ".align 8\n"                                       \
+                           ".globl " SYS_SYSCALL_ENTRYPOINT "\n"              \
+                           ".common " SYS_SYSCALL_ENTRYPOINT ",8,8\n"         \
+                           ".previous\n"                                      \
+                           /* Check the SYS_SYSCALL_ENTRYPOINT vector      */ \
+                           "push %%eax\n"                                     \
+                           "call 10000f\n"                                    \
+                     "10000:pop  %%eax\n"                                     \
+                           "add  $_GLOBAL_OFFSET_TABLE_+[.-10000b], %%eax\n"  \
+                           "mov  " SYS_SYSCALL_ENTRYPOINT                     \
+                                 "@GOT(%%eax), %%eax\n"                       \
+                           "mov  0(%%eax), %%eax\n"                           \
+                           "test %%eax, %%eax\n"                              \
+                           "jz   10002f\n"                                    \
+                           "push %%eax\n"                                     \
+                           "call 10001f\n"                                    \
+                     "10001:pop  %%eax\n"                                     \
+                           "add  $(10003f-10001b), %%eax\n"                   \
+                           "xchg 4(%%esp), %%eax\n"                           \
+                           "ret\n"                                            \
+                     "10002:pop  %%eax\n"                                     \
+                           "int $0x80\n"                                      \
+                     "10003:\n"
+    #else
+    #define LSS_ENTRYPOINT "int $0x80\n"
+    #endif
+    #undef  LSS_BODY
+    #define LSS_BODY(type,args...)                                            \
+      long __res;                                                             \
+      __asm__ __volatile__("push %%ebx\n"                                     \
+                           "movl %2,%%ebx\n"                                  \
+                           LSS_ENTRYPOINT                                     \
+                           "pop %%ebx"                                        \
+                           args                                               \
+                           : "esp", "memory");                                \
+      LSS_RETURN(type,__res)
+    #undef  _syscall0
+    #define _syscall0(type,name)                                              \
+      type LSS_NAME(name)(void) {                                             \
+        long __res;                                                           \
+        __asm__ volatile(LSS_ENTRYPOINT                                       \
+                         : "=a" (__res)                                       \
+                         : "0" (__NR_##name)                                  \
+                         : "memory");                                         \
+        LSS_RETURN(type,__res);                                               \
+      }
+    #undef  _syscall1
+    #define _syscall1(type,name,type1,arg1)                                   \
+      type LSS_NAME(name)(type1 arg1) {                                       \
+        LSS_BODY(type,                                                        \
+             : "=a" (__res)                                                   \
+             : "0" (__NR_##name), "ri" ((long)(arg1)));                       \
+      }
+    #undef  _syscall2
+    #define _syscall2(type,name,type1,arg1,type2,arg2)                        \
+      type LSS_NAME(name)(type1 arg1,type2 arg2) {                            \
+        LSS_BODY(type,                                                        \
+             : "=a" (__res)                                                   \
+             : "0" (__NR_##name),"ri" ((long)(arg1)), "c" ((long)(arg2)));    \
+      }
+    #undef  _syscall3
+    #define _syscall3(type,name,type1,arg1,type2,arg2,type3,arg3)             \
+      type LSS_NAME(name)(type1 arg1,type2 arg2,type3 arg3) {                 \
+        LSS_BODY(type,                                                        \
+             : "=a" (__res)                                                   \
+             : "0" (__NR_##name), "ri" ((long)(arg1)), "c" ((long)(arg2)),    \
+               "d" ((long)(arg3)));                                           \
+      }
+    #undef  _syscall4
+    #define _syscall4(type,name,type1,arg1,type2,arg2,type3,arg3,type4,arg4)  \
+      type LSS_NAME(name)(type1 arg1, type2 arg2, type3 arg3, type4 arg4) {   \
+        LSS_BODY(type,                                                        \
+             : "=a" (__res)                                                   \
+             : "0" (__NR_##name), "ri" ((long)(arg1)), "c" ((long)(arg2)),    \
+               "d" ((long)(arg3)),"S" ((long)(arg4)));                        \
+      }
+    #undef  _syscall5
+    #define _syscall5(type,name,type1,arg1,type2,arg2,type3,arg3,type4,arg4,  \
+                      type5,arg5)                                             \
+      type LSS_NAME(name)(type1 arg1, type2 arg2, type3 arg3, type4 arg4,     \
+                          type5 arg5) {                                       \
+        long __res;                                                           \
+        __asm__ __volatile__("push %%ebx\n"                                   \
+                             "movl %2,%%ebx\n"                                \
+                             "movl %1,%%eax\n"                                \
+                             LSS_ENTRYPOINT                                   \
+                             "pop  %%ebx"                                     \
+                             : "=a" (__res)                                   \
+                             : "i" (__NR_##name), "ri" ((long)(arg1)),        \
+                               "c" ((long)(arg2)), "d" ((long)(arg3)),        \
+                               "S" ((long)(arg4)), "D" ((long)(arg5))         \
+                             : "esp", "memory");                              \
+        LSS_RETURN(type,__res);                                               \
+      }
+    #undef  _syscall6
+    #define _syscall6(type,name,type1,arg1,type2,arg2,type3,arg3,type4,arg4,  \
+                      type5,arg5,type6,arg6)                                  \
+      type LSS_NAME(name)(type1 arg1, type2 arg2, type3 arg3, type4 arg4,     \
+                          type5 arg5, type6 arg6) {                           \
+        long __res;                                                           \
+        struct { long __a1; long __a6; } __s = { (long)arg1, (long) arg6 };   \
+        __asm__ __volatile__("push %%ebp\n"                                   \
+                             "push %%ebx\n"                                   \
+                             "movl 4(%2),%%ebp\n"                             \
+                             "movl 0(%2), %%ebx\n"                            \
+                             "movl %1,%%eax\n"                                \
+                             LSS_ENTRYPOINT                                   \
+                             "pop  %%ebx\n"                                   \
+                             "pop  %%ebp"                                     \
+                             : "=a" (__res)                                   \
+                             : "i" (__NR_##name),  "0" ((long)(&__s)),        \
+                               "c" ((long)(arg2)), "d" ((long)(arg3)),        \
+                               "S" ((long)(arg4)), "D" ((long)(arg5))         \
+                             : "esp", "memory");                              \
+        LSS_RETURN(type,__res);                                               \
+      }
+    LSS_INLINE int LSS_NAME(clone)(int (*fn)(void *), void *child_stack,
+                                   int flags, void *arg, int *parent_tidptr,
+                                   void *newtls, int *child_tidptr) {
+      long __res;
+      __asm__ __volatile__(/* if (fn == NULL)
+                            *   return -EINVAL;
+                            */
+                           "movl   %3,%%ecx\n"
+                           "jecxz  1f\n"
+
+                           /* if (child_stack == NULL)
+                            *   return -EINVAL;
+                            */
+                           "movl   %4,%%ecx\n"
+                           "jecxz  1f\n"
+
+                           /* Set up alignment of the child stack:
+                            * child_stack = (child_stack & ~0xF) - 20;
+                            */
+                           "andl   $-16,%%ecx\n"
+                           "subl   $20,%%ecx\n"
+
+                           /* Push "arg" and "fn" onto the stack that will be
+                            * used by the child.
+                            */
+                           "movl   %6,%%eax\n"
+                           "movl   %%eax,4(%%ecx)\n"
+                           "movl   %3,%%eax\n"
+                           "movl   %%eax,(%%ecx)\n"
+
+                           /* %eax = syscall(%eax = __NR_clone,
+                            *                %ebx = flags,
+                            *                %ecx = child_stack,
+                            *                %edx = parent_tidptr,
+                            *                %esi = newtls,
+                            *                %edi = child_tidptr)
+                            * Also, make sure that %ebx gets preserved as it is
+                            * used in PIC mode.
+                            */
+                           "movl   %8,%%esi\n"
+                           "movl   %7,%%edx\n"
+                           "movl   %5,%%eax\n"
+                           "movl   %9,%%edi\n"
+                           "pushl  %%ebx\n"
+                           "movl   %%eax,%%ebx\n"
+                           "movl   %2,%%eax\n"
+                           LSS_ENTRYPOINT
+
+                           /* In the parent: restore %ebx
+                            * In the child:  move "fn" into %ebx
+                            */
+                           "popl   %%ebx\n"
+
+                           /* if (%eax != 0)
+                            *   return %eax;
+                            */
+                           "test   %%eax,%%eax\n"
+                           "jnz    1f\n"
+
+                           /* In the child, now. Terminate frame pointer chain.
+                            */
+                           "movl   $0,%%ebp\n"
+
+                           /* Call "fn". "arg" is already on the stack.
+                            */
+                           "call   *%%ebx\n"
+
+                           /* Call _exit(%ebx). Unfortunately older versions
+                            * of gcc restrict the number of arguments that can
+                            * be passed to asm(). So, we need to hard-code the
+                            * system call number.
+                            */
+                           "movl   %%eax,%%ebx\n"
+                           "movl   $1,%%eax\n"
+                           LSS_ENTRYPOINT
+
+                           /* Return to parent.
+                            */
+                         "1:\n"
+                           : "=a" (__res)
+                           : "0"(-EINVAL), "i"(__NR_clone),
+                             "m"(fn), "m"(child_stack), "m"(flags), "m"(arg),
+                             "m"(parent_tidptr), "m"(newtls), "m"(child_tidptr)
+                           : "esp", "memory", "ecx", "edx", "esi", "edi");
+      LSS_RETURN(int, __res);
+    }
+
+    LSS_INLINE _syscall1(int, set_thread_area, void *, u)
+    LSS_INLINE _syscall1(int, get_thread_area, void *, u)
+
+    LSS_INLINE void (*LSS_NAME(restore_rt)(void))(void) {
+      /* On i386, the kernel does not know how to return from a signal
+       * handler. Instead, it relies on user space to provide a
+       * restorer function that calls the {rt_,}sigreturn() system call.
+       * Unfortunately, we cannot just reference the glibc version of this
+       * function, as glibc goes out of its way to make it inaccessible.
+       */
+      void (*res)(void);
+      __asm__ __volatile__("call   2f\n"
+                         "0:.align 16\n"
+                         "1:movl   %1,%%eax\n"
+                           LSS_ENTRYPOINT
+                         "2:popl   %0\n"
+                           "addl   $(1b-0b),%0\n"
+                           : "=a" (res)
+                           : "i"  (__NR_rt_sigreturn));
+      return res;
+    }
+    LSS_INLINE void (*LSS_NAME(restore)(void))(void) {
+      /* On i386, the kernel does not know how to return from a signal
+       * handler. Instead, it relies on user space to provide a
+       * restorer function that calls the {rt_,}sigreturn() system call.
+       * Unfortunately, we cannot just reference the glibc version of this
+       * function, as glibc goes out of its way to make it inaccessible.
+       */
+      void (*res)(void);
+      __asm__ __volatile__("call   2f\n"
+                         "0:.align 16\n"
+                         "1:pop    %%eax\n"
+                           "movl   %1,%%eax\n"
+                           LSS_ENTRYPOINT
+                         "2:popl   %0\n"
+                           "addl   $(1b-0b),%0\n"
+                           : "=a" (res)
+                           : "i"  (__NR_sigreturn));
+      return res;
+    }
+  #elif defined(__x86_64__)
+    /* There are no known problems with any of the _syscallX() macros
+     * currently shipping for x86_64, but we still need to be able to define
+     * our own version so that we can override the location of the errno
+     * location (e.g. when using the clone() system call with the CLONE_VM
+     * option).
+     */
+    #undef LSS_ENTRYPOINT
+    #ifdef SYS_SYSCALL_ENTRYPOINT
+    static inline void (**LSS_NAME(get_syscall_entrypoint)(void))(void) {
+      void (**entrypoint)(void);
+      asm volatile(".bss\n"
+                   ".align 8\n"
+                   ".globl " SYS_SYSCALL_ENTRYPOINT "\n"
+                   ".common " SYS_SYSCALL_ENTRYPOINT ",8,8\n"
+                   ".previous\n"
+                   "mov " SYS_SYSCALL_ENTRYPOINT "@GOTPCREL(%%rip), %0\n"
+                   : "=r"(entrypoint));
+      return entrypoint;
+    }
+
+    #define LSS_ENTRYPOINT                                                    \
+              ".bss\n"                                                        \
+              ".align 8\n"                                                    \
+              ".globl " SYS_SYSCALL_ENTRYPOINT "\n"                           \
+              ".common " SYS_SYSCALL_ENTRYPOINT ",8,8\n"                      \
+              ".previous\n"                                                   \
+              "mov " SYS_SYSCALL_ENTRYPOINT "@GOTPCREL(%%rip), %%rcx\n"       \
+              "mov  0(%%rcx), %%rcx\n"                                        \
+              "test %%rcx, %%rcx\n"                                           \
+              "jz   10001f\n"                                                 \
+              "call *%%rcx\n"                                                 \
+              "jmp  10002f\n"                                                 \
+        "10001:syscall\n"                                                     \
+        "10002:\n"
+
+    #else
+    #define LSS_ENTRYPOINT "syscall\n"
+    #endif
+
+    /* The x32 ABI has 32 bit longs, but the syscall interface is 64 bit.
+     * We need to explicitly cast to an unsigned 64 bit type to avoid implicit
+     * sign extension.  We can't cast pointers directly because those are
+     * 32 bits, and gcc will dump ugly warnings about casting from a pointer
+     * to an integer of a different size.
+     */
+    #undef  LSS_SYSCALL_ARG
+    #define LSS_SYSCALL_ARG(a) ((uint64_t)(uintptr_t)(a))
+    #undef  _LSS_RETURN
+    #define _LSS_RETURN(type, res, cast)                                      \
+      do {                                                                    \
+        if ((uint64_t)(res) >= (uint64_t)(-4095)) {                           \
+          LSS_ERRNO = -(res);                                                 \
+          res = -1;                                                           \
+        }                                                                     \
+        return (type)(cast)(res);                                             \
+      } while (0)
+    #undef  LSS_RETURN
+    #define LSS_RETURN(type, res) _LSS_RETURN(type, res, uintptr_t)
+
+    #undef  _LSS_BODY
+    #define _LSS_BODY(nr, type, name, cast, ...)                              \
+          long long __res;                                                    \
+          __asm__ __volatile__(LSS_BODY_ASM##nr LSS_ENTRYPOINT                \
+            : "=a" (__res)                                                    \
+            : "0" (__NR_##name) LSS_BODY_ARG##nr(__VA_ARGS__)                 \
+            : LSS_BODY_CLOBBER##nr "r11", "rcx", "memory");                   \
+          _LSS_RETURN(type, __res, cast)
+    #undef  LSS_BODY
+    #define LSS_BODY(nr, type, name, args...) \
+      _LSS_BODY(nr, type, name, uintptr_t, ## args)
+
+    #undef  LSS_BODY_ASM0
+    #undef  LSS_BODY_ASM1
+    #undef  LSS_BODY_ASM2
+    #undef  LSS_BODY_ASM3
+    #undef  LSS_BODY_ASM4
+    #undef  LSS_BODY_ASM5
+    #undef  LSS_BODY_ASM6
+    #define LSS_BODY_ASM0
+    #define LSS_BODY_ASM1 LSS_BODY_ASM0
+    #define LSS_BODY_ASM2 LSS_BODY_ASM1
+    #define LSS_BODY_ASM3 LSS_BODY_ASM2
+    #define LSS_BODY_ASM4 LSS_BODY_ASM3 "movq %5,%%r10;"
+    #define LSS_BODY_ASM5 LSS_BODY_ASM4 "movq %6,%%r8;"
+    #define LSS_BODY_ASM6 LSS_BODY_ASM5 "movq %7,%%r9;"
+
+    #undef  LSS_BODY_CLOBBER0
+    #undef  LSS_BODY_CLOBBER1
+    #undef  LSS_BODY_CLOBBER2
+    #undef  LSS_BODY_CLOBBER3
+    #undef  LSS_BODY_CLOBBER4
+    #undef  LSS_BODY_CLOBBER5
+    #undef  LSS_BODY_CLOBBER6
+    #define LSS_BODY_CLOBBER0
+    #define LSS_BODY_CLOBBER1 LSS_BODY_CLOBBER0
+    #define LSS_BODY_CLOBBER2 LSS_BODY_CLOBBER1
+    #define LSS_BODY_CLOBBER3 LSS_BODY_CLOBBER2
+    #define LSS_BODY_CLOBBER4 LSS_BODY_CLOBBER3 "r10",
+    #define LSS_BODY_CLOBBER5 LSS_BODY_CLOBBER4 "r8",
+    #define LSS_BODY_CLOBBER6 LSS_BODY_CLOBBER5 "r9",
+
+    #undef  LSS_BODY_ARG0
+    #undef  LSS_BODY_ARG1
+    #undef  LSS_BODY_ARG2
+    #undef  LSS_BODY_ARG3
+    #undef  LSS_BODY_ARG4
+    #undef  LSS_BODY_ARG5
+    #undef  LSS_BODY_ARG6
+    #define LSS_BODY_ARG0()
+    #define LSS_BODY_ARG1(arg1) \
+      LSS_BODY_ARG0(), "D" (arg1)
+    #define LSS_BODY_ARG2(arg1, arg2) \
+      LSS_BODY_ARG1(arg1), "S" (arg2)
+    #define LSS_BODY_ARG3(arg1, arg2, arg3) \
+      LSS_BODY_ARG2(arg1, arg2), "d" (arg3)
+    #define LSS_BODY_ARG4(arg1, arg2, arg3, arg4) \
+      LSS_BODY_ARG3(arg1, arg2, arg3), "r" (arg4)
+    #define LSS_BODY_ARG5(arg1, arg2, arg3, arg4, arg5) \
+      LSS_BODY_ARG4(arg1, arg2, arg3, arg4), "r" (arg5)
+    #define LSS_BODY_ARG6(arg1, arg2, arg3, arg4, arg5, arg6) \
+      LSS_BODY_ARG5(arg1, arg2, arg3, arg4, arg5), "r" (arg6)
+
+    #undef _syscall0
+    #define _syscall0(type,name)                                              \
+      type LSS_NAME(name)(void) {                                             \
+        LSS_BODY(0, type, name);                                              \
+      }
+    #undef _syscall1
+    #define _syscall1(type,name,type1,arg1)                                   \
+      type LSS_NAME(name)(type1 arg1) {                                       \
+        LSS_BODY(1, type, name, LSS_SYSCALL_ARG(arg1));                       \
+      }
+    #undef _syscall2
+    #define _syscall2(type,name,type1,arg1,type2,arg2)                        \
+      type LSS_NAME(name)(type1 arg1, type2 arg2) {                           \
+        LSS_BODY(2, type, name, LSS_SYSCALL_ARG(arg1), LSS_SYSCALL_ARG(arg2));\
+      }
+    #undef _syscall3
+    #define _syscall3(type,name,type1,arg1,type2,arg2,type3,arg3)             \
+      type LSS_NAME(name)(type1 arg1, type2 arg2, type3 arg3) {               \
+        LSS_BODY(3, type, name, LSS_SYSCALL_ARG(arg1), LSS_SYSCALL_ARG(arg2), \
+                                LSS_SYSCALL_ARG(arg3));                       \
+      }
+    #undef _syscall4
+    #define _syscall4(type,name,type1,arg1,type2,arg2,type3,arg3,type4,arg4)  \
+      type LSS_NAME(name)(type1 arg1, type2 arg2, type3 arg3, type4 arg4) {   \
+        LSS_BODY(4, type, name, LSS_SYSCALL_ARG(arg1), LSS_SYSCALL_ARG(arg2), \
+                                LSS_SYSCALL_ARG(arg3), LSS_SYSCALL_ARG(arg4));\
+      }
+    #undef _syscall5
+    #define _syscall5(type,name,type1,arg1,type2,arg2,type3,arg3,type4,arg4,  \
+                      type5,arg5)                                             \
+      type LSS_NAME(name)(type1 arg1, type2 arg2, type3 arg3, type4 arg4,     \
+                          type5 arg5) {                                       \
+        LSS_BODY(5, type, name, LSS_SYSCALL_ARG(arg1), LSS_SYSCALL_ARG(arg2), \
+                                LSS_SYSCALL_ARG(arg3), LSS_SYSCALL_ARG(arg4), \
+                                LSS_SYSCALL_ARG(arg5));                       \
+      }
+    #undef _syscall6
+    #define _syscall6(type,name,type1,arg1,type2,arg2,type3,arg3,type4,arg4,  \
+                      type5,arg5,type6,arg6)                                  \
+      type LSS_NAME(name)(type1 arg1, type2 arg2, type3 arg3, type4 arg4,     \
+                          type5 arg5, type6 arg6) {                           \
+        LSS_BODY(6, type, name, LSS_SYSCALL_ARG(arg1), LSS_SYSCALL_ARG(arg2), \
+                                LSS_SYSCALL_ARG(arg3), LSS_SYSCALL_ARG(arg4), \
+                                LSS_SYSCALL_ARG(arg5), LSS_SYSCALL_ARG(arg6));\
+      }
+    LSS_INLINE int LSS_NAME(clone)(int (*fn)(void *), void *child_stack,
+                                   int flags, void *arg, int *parent_tidptr,
+                                   void *newtls, int *child_tidptr) {
+      long long __res;
+      {
+        __asm__ __volatile__(/* if (fn == NULL)
+                              *   return -EINVAL;
+                              */
+                             "testq  %4,%4\n"
+                             "jz     1f\n"
+
+                             /* if (child_stack == NULL)
+                              *   return -EINVAL;
+                              */
+                             "testq  %5,%5\n"
+                             "jz     1f\n"
+
+                             /* childstack -= 2*sizeof(void *);
+                              */
+                             "subq   $16,%5\n"
+
+                             /* Push "arg" and "fn" onto the stack that will be
+                              * used by the child.
+                              */
+                             "movq   %7,8(%5)\n"
+                             "movq   %4,0(%5)\n"
+
+                             /* %rax = syscall(%rax = __NR_clone,
+                              *                %rdi = flags,
+                              *                %rsi = child_stack,
+                              *                %rdx = parent_tidptr,
+                              *                %r8  = new_tls,
+                              *                %r10 = child_tidptr)
+                              */
+                             "movq   %2,%%rax\n"
+                             "movq   %9,%%r8\n"
+                             "movq   %10,%%r10\n"
+                             LSS_ENTRYPOINT
+
+                             /* if (%rax != 0)
+                              *   return;
+                              */
+                             "testq  %%rax,%%rax\n"
+                             "jnz    1f\n"
+
+                             /* In the child. Terminate frame pointer chain.
+                              */
+                             "xorq   %%rbp,%%rbp\n"
+
+                             /* Call "fn(arg)".
+                              */
+                             "popq   %%rax\n"
+                             "popq   %%rdi\n"
+                             "call   *%%rax\n"
+
+                             /* Call _exit(%ebx).
+                              */
+                             "movq   %%rax,%%rdi\n"
+                             "movq   %3,%%rax\n"
+                             LSS_ENTRYPOINT
+
+                             /* Return to parent.
+                              */
+                           "1:\n"
+                             : "=a" (__res)
+                             : "0"(-EINVAL), "i"(__NR_clone), "i"(__NR_exit),
+                               "r"(LSS_SYSCALL_ARG(fn)),
+                               "S"(LSS_SYSCALL_ARG(child_stack)),
+                               "D"(LSS_SYSCALL_ARG(flags)),
+                               "r"(LSS_SYSCALL_ARG(arg)),
+                               "d"(LSS_SYSCALL_ARG(parent_tidptr)),
+                               "r"(LSS_SYSCALL_ARG(newtls)),
+                               "r"(LSS_SYSCALL_ARG(child_tidptr))
+                             : "memory", "r8", "r10", "r11", "rcx");
+      }
+      LSS_RETURN(int, __res);
+    }
+    LSS_INLINE _syscall2(int, arch_prctl, int, c, void *, a)
+
+    LSS_INLINE void (*LSS_NAME(restore_rt)(void))(void) {
+      /* On x86-64, the kernel does not know how to return from
+       * a signal handler. Instead, it relies on user space to provide a
+       * restorer function that calls the rt_sigreturn() system call.
+       * Unfortunately, we cannot just reference the glibc version of this
+       * function, as glibc goes out of its way to make it inaccessible.
+       */
+      long long res;
+      __asm__ __volatile__("jmp    2f\n"
+                           ".align 16\n"
+                         "1:movq   %1,%%rax\n"
+                           LSS_ENTRYPOINT
+                         "2:leaq   1b(%%rip),%0\n"
+                           : "=r" (res)
+                           : "i"  (__NR_rt_sigreturn));
+      return (void (*)(void))(uintptr_t)res;
+    }
+  #elif defined(__ARM_ARCH_3__)
+    /* Most definitions of _syscallX() neglect to mark "memory" as being
+     * clobbered. This causes problems with compilers, that do a better job
+     * at optimizing across __asm__ calls.
+     * So, we just have to redefine all of the _syscallX() macros.
+     */
+    #undef LSS_REG
+    #define LSS_REG(r,a) register long __r##r __asm__("r"#r) = (long)a
+    #undef  LSS_BODY
+    #define LSS_BODY(type,name,args...)                                       \
+          register long __res_r0 __asm__("r0");                               \
+          long __res;                                                         \
+          __asm__ __volatile__ (__syscall(name)                               \
+                                : "=r"(__res_r0) : args : "lr", "memory");    \
+          __res = __res_r0;                                                   \
+          LSS_RETURN(type, __res)
+    #undef _syscall0
+    #define _syscall0(type, name)                                             \
+      type LSS_NAME(name)(void) {                                             \
+        LSS_BODY(type, name);                                                 \
+      }
+    #undef _syscall1
+    #define _syscall1(type, name, type1, arg1)                                \
+      type LSS_NAME(name)(type1 arg1) {                                       \
+        LSS_REG(0, arg1); LSS_BODY(type, name, "r"(__r0));                    \
+      }
+    #undef _syscall2
+    #define _syscall2(type, name, type1, arg1, type2, arg2)                   \
+      type LSS_NAME(name)(type1 arg1, type2 arg2) {                           \
+        LSS_REG(0, arg1); LSS_REG(1, arg2);                                   \
+        LSS_BODY(type, name, "r"(__r0), "r"(__r1));                           \
+      }
+    #undef _syscall3
+    #define _syscall3(type, name, type1, arg1, type2, arg2, type3, arg3)      \
+      type LSS_NAME(name)(type1 arg1, type2 arg2, type3 arg3) {               \
+        LSS_REG(0, arg1); LSS_REG(1, arg2); LSS_REG(2, arg3);                 \
+        LSS_BODY(type, name, "r"(__r0), "r"(__r1), "r"(__r2));                \
+      }
+    #undef _syscall4
+    #define _syscall4(type,name,type1,arg1,type2,arg2,type3,arg3,type4,arg4)  \
+      type LSS_NAME(name)(type1 arg1, type2 arg2, type3 arg3, type4 arg4) {   \
+        LSS_REG(0, arg1); LSS_REG(1, arg2); LSS_REG(2, arg3);                 \
+        LSS_REG(3, arg4);                                                     \
+        LSS_BODY(type, name, "r"(__r0), "r"(__r1), "r"(__r2), "r"(__r3));     \
+      }
+    #undef _syscall5
+    #define _syscall5(type,name,type1,arg1,type2,arg2,type3,arg3,type4,arg4,  \
+                      type5,arg5)                                             \
+      type LSS_NAME(name)(type1 arg1, type2 arg2, type3 arg3, type4 arg4,     \
+                          type5 arg5) {                                       \
+        LSS_REG(0, arg1); LSS_REG(1, arg2); LSS_REG(2, arg3);                 \
+        LSS_REG(3, arg4); LSS_REG(4, arg5);                                   \
+        LSS_BODY(type, name, "r"(__r0), "r"(__r1), "r"(__r2), "r"(__r3),      \
+                             "r"(__r4));                                      \
+      }
+    #undef _syscall6
+    #define _syscall6(type,name,type1,arg1,type2,arg2,type3,arg3,type4,arg4,  \
+                      type5,arg5,type6,arg6)                                  \
+      type LSS_NAME(name)(type1 arg1, type2 arg2, type3 arg3, type4 arg4,     \
+                          type5 arg5, type6 arg6) {                           \
+        LSS_REG(0, arg1); LSS_REG(1, arg2); LSS_REG(2, arg3);                 \
+        LSS_REG(3, arg4); LSS_REG(4, arg5); LSS_REG(5, arg6);                 \
+        LSS_BODY(type, name, "r"(__r0), "r"(__r1), "r"(__r2), "r"(__r3),      \
+                             "r"(__r4), "r"(__r5));                           \
+      }
+    LSS_INLINE int LSS_NAME(clone)(int (*fn)(void *), void *child_stack,
+                                   int flags, void *arg, int *parent_tidptr,
+                                   void *newtls, int *child_tidptr) {
+      long __res;
+      {
+        register int   __flags __asm__("r0") = flags;
+        register void *__stack __asm__("r1") = child_stack;
+        register void *__ptid  __asm__("r2") = parent_tidptr;
+        register void *__tls   __asm__("r3") = newtls;
+        register int  *__ctid  __asm__("r4") = child_tidptr;
+        __asm__ __volatile__(/* if (fn == NULL || child_stack == NULL)
+                              *   return -EINVAL;
+                              */
+                             "cmp   %2,#0\n"
+                             "cmpne %3,#0\n"
+                             "moveq %0,%1\n"
+                             "beq   1f\n"
+
+                             /* Push "arg" and "fn" onto the stack that will be
+                              * used by the child.
+                              */
+                             "str   %5,[%3,#-4]!\n"
+                             "str   %2,[%3,#-4]!\n"
+
+                             /* %r0 = syscall(%r0 = flags,
+                              *               %r1 = child_stack,
+                              *               %r2 = parent_tidptr,
+                              *               %r3 = newtls,
+                              *               %r4 = child_tidptr)
+                              */
+                             __syscall(clone)"\n"
+
+                             /* if (%r0 != 0)
+                              *   return %r0;
+                              */
+                             "movs  %0,r0\n"
+                             "bne   1f\n"
+
+                             /* In the child, now. Call "fn(arg)".
+                              */
+                             "ldr   r0,[sp, #4]\n"
+                             "mov   lr,pc\n"
+                             "ldr   pc,[sp]\n"
+
+                             /* Call _exit(%r0).
+                              */
+                             __syscall(exit)"\n"
+                           "1:\n"
+                             : "=r" (__res)
+                             : "i"(-EINVAL),
+                               "r"(fn), "r"(__stack), "r"(__flags), "r"(arg),
+                               "r"(__ptid), "r"(__tls), "r"(__ctid)
+                             : "cc", "lr", "memory");
+      }
+      LSS_RETURN(int, __res);
+    }
+  #elif defined(__ARM_EABI__)
+    /* Most definitions of _syscallX() neglect to mark "memory" as being
+     * clobbered. This causes problems with compilers, that do a better job
+     * at optimizing across __asm__ calls.
+     * So, we just have to redefine all fo the _syscallX() macros.
+     */
+    #undef LSS_REG
+    #define LSS_REG(r,a) register long __r##r __asm__("r"#r) = (long)a
+    #undef  LSS_BODY
+    #define LSS_BODY(type,name,args...)                                       \
+          register long __res_r0 __asm__("r0");                               \
+          long __res;                                                         \
+          __asm__ __volatile__ ("push {r7}\n"                                 \
+                                "mov r7, %1\n"                                \
+                                "swi 0x0\n"                                   \
+                                "pop {r7}\n"                                  \
+                                : "=r"(__res_r0)                              \
+                                : "i"(__NR_##name) , ## args                  \
+                                : "lr", "memory");                            \
+          __res = __res_r0;                                                   \
+          LSS_RETURN(type, __res)
+    #undef _syscall0
+    #define _syscall0(type, name)                                             \
+      type LSS_NAME(name)(void) {                                             \
+        LSS_BODY(type, name);                                                 \
+      }
+    #undef _syscall1
+    #define _syscall1(type, name, type1, arg1)                                \
+      type LSS_NAME(name)(type1 arg1) {                                       \
+        LSS_REG(0, arg1); LSS_BODY(type, name, "r"(__r0));                    \
+      }
+    #undef _syscall2
+    #define _syscall2(type, name, type1, arg1, type2, arg2)                   \
+      type LSS_NAME(name)(type1 arg1, type2 arg2) {                           \
+        LSS_REG(0, arg1); LSS_REG(1, arg2);                                   \
+        LSS_BODY(type, name, "r"(__r0), "r"(__r1));                           \
+      }
+    #undef _syscall3
+    #define _syscall3(type, name, type1, arg1, type2, arg2, type3, arg3)      \
+      type LSS_NAME(name)(type1 arg1, type2 arg2, type3 arg3) {               \
+        LSS_REG(0, arg1); LSS_REG(1, arg2); LSS_REG(2, arg3);                 \
+        LSS_BODY(type, name, "r"(__r0), "r"(__r1), "r"(__r2));                \
+      }
+    #undef _syscall4
+    #define _syscall4(type,name,type1,arg1,type2,arg2,type3,arg3,type4,arg4)  \
+      type LSS_NAME(name)(type1 arg1, type2 arg2, type3 arg3, type4 arg4) {   \
+        LSS_REG(0, arg1); LSS_REG(1, arg2); LSS_REG(2, arg3);                 \
+        LSS_REG(3, arg4);                                                     \
+        LSS_BODY(type, name, "r"(__r0), "r"(__r1), "r"(__r2), "r"(__r3));     \
+      }
+    #undef _syscall5
+    #define _syscall5(type,name,type1,arg1,type2,arg2,type3,arg3,type4,arg4,  \
+                      type5,arg5)                                             \
+      type LSS_NAME(name)(type1 arg1, type2 arg2, type3 arg3, type4 arg4,     \
+                          type5 arg5) {                                       \
+        LSS_REG(0, arg1); LSS_REG(1, arg2); LSS_REG(2, arg3);                 \
+        LSS_REG(3, arg4); LSS_REG(4, arg5);                                   \
+        LSS_BODY(type, name, "r"(__r0), "r"(__r1), "r"(__r2), "r"(__r3),      \
+                             "r"(__r4));                                      \
+      }
+    #undef _syscall6
+    #define _syscall6(type,name,type1,arg1,type2,arg2,type3,arg3,type4,arg4,  \
+                      type5,arg5,type6,arg6)                                  \
+      type LSS_NAME(name)(type1 arg1, type2 arg2, type3 arg3, type4 arg4,     \
+                          type5 arg5, type6 arg6) {                           \
+        LSS_REG(0, arg1); LSS_REG(1, arg2); LSS_REG(2, arg3);                 \
+        LSS_REG(3, arg4); LSS_REG(4, arg5); LSS_REG(5, arg6);                 \
+        LSS_BODY(type, name, "r"(__r0), "r"(__r1), "r"(__r2), "r"(__r3),      \
+                             "r"(__r4), "r"(__r5));                           \
+      }
+    LSS_INLINE int LSS_NAME(clone)(int (*fn)(void *), void *child_stack,
+                                   int flags, void *arg, int *parent_tidptr,
+                                   void *newtls, int *child_tidptr) {
+      long __res;
+      if (fn == NULL || child_stack == NULL) {
+        __res = -EINVAL;
+        LSS_RETURN(int, __res);
+      }
+
+      /* Push "arg" and "fn" onto the stack that will be
+       * used by the child.
+       */
+      {
+        uintptr_t* cstack = (uintptr_t*)child_stack - 2;
+        cstack[0] = (uintptr_t)fn;
+        cstack[1] = (uintptr_t)arg;
+        child_stack = cstack;
+      }
+      {
+        register int   __flags __asm__("r0") = flags;
+        register void *__stack __asm__("r1") = child_stack;
+        register void *__ptid  __asm__("r2") = parent_tidptr;
+        register void *__tls   __asm__("r3") = newtls;
+        register int  *__ctid  __asm__("r4") = child_tidptr;
+        __asm__ __volatile__(
+#ifdef __thumb2__
+            "push {r7}\n"
+#endif
+            /* %r0 = syscall(%r0 = flags,
+             *               %r1 = child_stack,
+             *               %r2 = parent_tidptr,
+             *               %r3 = newtls,
+             *               %r4 = child_tidptr)
+             */
+            "mov r7, %6\n"
+            "swi 0x0\n"
+
+            /* if (%r0 != 0)
+             *   return %r0;
+             */
+            "cmp   r0, #0\n"
+            "bne   1f\n"
+
+            /* In the child, now. Call "fn(arg)".
+             */
+            "ldr   r0,[sp, #4]\n"
+
+            "ldr   lr,[sp]\n"
+            "blx   lr\n"
+
+            /* Call _exit(%r0).
+             */
+            "mov r7, %7\n"
+            "swi 0x0\n"
+            /* Unreachable */
+            "bkpt #0\n"
+         "1:\n"
+#ifdef __thumb2__
+            "pop {r7}\n"
+#endif
+            "movs  %0,r0\n"
+            : "=r"(__res)
+            : "r"(__stack), "r"(__flags), "r"(__ptid), "r"(__tls), "r"(__ctid),
+              "i"(__NR_clone), "i"(__NR_exit)
+            : "cc", "lr", "memory"
+#ifndef __thumb2__
+            , "r7"
+#endif
+            );
+      }
+      LSS_RETURN(int, __res);
+    }
+  #elif defined(__aarch64__)
+    /* Most definitions of _syscallX() neglect to mark "memory" as being
+     * clobbered. This causes problems with compilers, that do a better job
+     * at optimizing across __asm__ calls.
+     * So, we just have to redefine all of the _syscallX() macros.
+     */
+    #undef LSS_REG
+    #define LSS_REG(r,a) register int64_t __r##r __asm__("x"#r) = (int64_t)a
+    #undef  LSS_BODY
+    #define LSS_BODY(type,name,args...)                                       \
+          register int64_t __res_x0 __asm__("x0");                            \
+          int64_t __res;                                                      \
+          __asm__ __volatile__ ("mov x8, %1\n"                                \
+                                "svc 0x0\n"                                   \
+                                : "=r"(__res_x0)                              \
+                                : "i"(__NR_##name) , ## args                  \
+                                : "x8", "memory");                            \
+          __res = __res_x0;                                                   \
+          LSS_RETURN(type, __res)
+    #undef _syscall0
+    #define _syscall0(type, name)                                             \
+      type LSS_NAME(name)(void) {                                             \
+        LSS_BODY(type, name);                                                 \
+      }
+    #undef _syscall1
+    #define _syscall1(type, name, type1, arg1)                                \
+      type LSS_NAME(name)(type1 arg1) {                                       \
+        LSS_REG(0, arg1); LSS_BODY(type, name, "r"(__r0));                    \
+      }
+    #undef _syscall2
+    #define _syscall2(type, name, type1, arg1, type2, arg2)                   \
+      type LSS_NAME(name)(type1 arg1, type2 arg2) {                           \
+        LSS_REG(0, arg1); LSS_REG(1, arg2);                                   \
+        LSS_BODY(type, name, "r"(__r0), "r"(__r1));                           \
+      }
+    #undef _syscall3
+    #define _syscall3(type, name, type1, arg1, type2, arg2, type3, arg3)      \
+      type LSS_NAME(name)(type1 arg1, type2 arg2, type3 arg3) {               \
+        LSS_REG(0, arg1); LSS_REG(1, arg2); LSS_REG(2, arg3);                 \
+        LSS_BODY(type, name, "r"(__r0), "r"(__r1), "r"(__r2));                \
+      }
+    #undef _syscall4
+    #define _syscall4(type,name,type1,arg1,type2,arg2,type3,arg3,type4,arg4)  \
+      type LSS_NAME(name)(type1 arg1, type2 arg2, type3 arg3, type4 arg4) {   \
+        LSS_REG(0, arg1); LSS_REG(1, arg2); LSS_REG(2, arg3);                 \
+        LSS_REG(3, arg4);                                                     \
+        LSS_BODY(type, name, "r"(__r0), "r"(__r1), "r"(__r2), "r"(__r3));     \
+      }
+    #undef _syscall5
+    #define _syscall5(type,name,type1,arg1,type2,arg2,type3,arg3,type4,arg4,  \
+                      type5,arg5)                                             \
+      type LSS_NAME(name)(type1 arg1, type2 arg2, type3 arg3, type4 arg4,     \
+                          type5 arg5) {                                       \
+        LSS_REG(0, arg1); LSS_REG(1, arg2); LSS_REG(2, arg3);                 \
+        LSS_REG(3, arg4); LSS_REG(4, arg5);                                   \
+        LSS_BODY(type, name, "r"(__r0), "r"(__r1), "r"(__r2), "r"(__r3),      \
+                             "r"(__r4));                                      \
+      }
+    #undef _syscall6
+    #define _syscall6(type,name,type1,arg1,type2,arg2,type3,arg3,type4,arg4,  \
+                      type5,arg5,type6,arg6)                                  \
+      type LSS_NAME(name)(type1 arg1, type2 arg2, type3 arg3, type4 arg4,     \
+                          type5 arg5, type6 arg6) {                           \
+        LSS_REG(0, arg1); LSS_REG(1, arg2); LSS_REG(2, arg3);                 \
+        LSS_REG(3, arg4); LSS_REG(4, arg5); LSS_REG(5, arg6);                 \
+        LSS_BODY(type, name, "r"(__r0), "r"(__r1), "r"(__r2), "r"(__r3),      \
+                             "r"(__r4), "r"(__r5));                           \
+      }
+
+    LSS_INLINE int LSS_NAME(clone)(int (*fn)(void *), void *child_stack,
+                                   int flags, void *arg, int *parent_tidptr,
+                                   void *newtls, int *child_tidptr) {
+      int64_t __res;
+      {
+        register uint64_t __flags __asm__("x0") = flags;
+        register void *__stack __asm__("x1") = child_stack;
+        register void *__ptid  __asm__("x2") = parent_tidptr;
+        register void *__tls   __asm__("x3") = newtls;
+        register int  *__ctid  __asm__("x4") = child_tidptr;
+        __asm__ __volatile__(/* Push "arg" and "fn" onto the stack that will be
+                              * used by the child.
+                              */
+                             "stp     %1, %4, [%2, #-16]!\n"
+
+                             /* %x0 = syscall(%x0 = flags,
+                              *               %x1 = child_stack,
+                              *               %x2 = parent_tidptr,
+                              *               %x3 = newtls,
+                              *               %x4 = child_tidptr)
+                              */
+                             "mov     x8, %8\n"
+                             "svc     0x0\n"
+
+                             /* if (%r0 != 0)
+                              *   return %r0;
+                              */
+                             "mov     %0, x0\n"
+                             "cbnz    x0, 1f\n"
+
+                             /* In the child, now. Call "fn(arg)".
+                              */
+                             "ldp     x1, x0, [sp], #16\n"
+                             "blr     x1\n"
+
+                             /* Call _exit(%r0).
+                              */
+                             "mov     x8, %9\n"
+                             "svc     0x0\n"
+                           "1:\n"
+                             : "=r" (__res)
+                             : "r"(fn), "r"(__stack), "r"(__flags), "r"(arg),
+                               "r"(__ptid), "r"(__tls), "r"(__ctid),
+                               "i"(__NR_clone), "i"(__NR_exit)
+                             : "cc", "x8", "memory");
+      }
+      LSS_RETURN(int, __res);
+    }
+  #elif defined(__mips__)
+    #undef LSS_REG
+    #define LSS_REG(r,a) register unsigned long __r##r __asm__("$"#r) =       \
+                                 (unsigned long)(a)
+    #undef  LSS_BODY
+    #undef LSS_SYSCALL_CLOBBERS
+    #if _MIPS_SIM == _MIPS_SIM_ABI32
+    #define LSS_SYSCALL_CLOBBERS "$1", "$3", "$8", "$9", "$10",               \
+                                 "$11", "$12", "$13", "$14", "$15",           \
+                                 "$24", "$25", "hi", "lo", "memory"
+    #else
+    #define LSS_SYSCALL_CLOBBERS "$1", "$3", "$10", "$11", "$12",             \
+                                 "$13", "$14", "$15", "$24", "$25",           \
+                                 "hi", "lo", "memory"
+    #endif
+    #define LSS_BODY(type,name,r7,...)                                        \
+          register unsigned long __v0 __asm__("$2") = __NR_##name;            \
+          __asm__ __volatile__ ("syscall\n"                                   \
+                                : "=r"(__v0), r7 (__r7)                       \
+                                : "0"(__v0), ##__VA_ARGS__                    \
+                                : LSS_SYSCALL_CLOBBERS);                      \
+          LSS_RETURN(type, __v0, __r7)
+    #undef _syscall0
+    #define _syscall0(type, name)                                             \
+      type LSS_NAME(name)(void) {                                             \
+        register unsigned long __r7 __asm__("$7");                            \
+        LSS_BODY(type, name, "=r");                                           \
+      }
+    #undef _syscall1
+    #define _syscall1(type, name, type1, arg1)                                \
+      type LSS_NAME(name)(type1 arg1) {                                       \
+        register unsigned long __r7 __asm__("$7");                            \
+        LSS_REG(4, arg1); LSS_BODY(type, name, "=r", "r"(__r4));              \
+      }
+    #undef _syscall2
+    #define _syscall2(type, name, type1, arg1, type2, arg2)                   \
+      type LSS_NAME(name)(type1 arg1, type2 arg2) {                           \
+        register unsigned long __r7 __asm__("$7");                            \
+        LSS_REG(4, arg1); LSS_REG(5, arg2);                                   \
+        LSS_BODY(type, name, "=r", "r"(__r4), "r"(__r5));                     \
+      }
+    #undef _syscall3
+    #define _syscall3(type, name, type1, arg1, type2, arg2, type3, arg3)      \
+      type LSS_NAME(name)(type1 arg1, type2 arg2, type3 arg3) {               \
+        register unsigned long __r7 __asm__("$7");                            \
+        LSS_REG(4, arg1); LSS_REG(5, arg2); LSS_REG(6, arg3);                 \
+        LSS_BODY(type, name, "=r", "r"(__r4), "r"(__r5), "r"(__r6));          \
+      }
+    #undef _syscall4
+    #define _syscall4(type,name,type1,arg1,type2,arg2,type3,arg3,type4,arg4)  \
+      type LSS_NAME(name)(type1 arg1, type2 arg2, type3 arg3, type4 arg4) {   \
+        LSS_REG(4, arg1); LSS_REG(5, arg2); LSS_REG(6, arg3);                 \
+        LSS_REG(7, arg4);                                                     \
+        LSS_BODY(type, name, "+r", "r"(__r4), "r"(__r5), "r"(__r6));          \
+      }
+    #undef _syscall5
+    #if _MIPS_SIM == _MIPS_SIM_ABI32
+    /* The old 32bit MIPS system call API passes the fifth and sixth argument
+     * on the stack, whereas the new APIs use registers "r8" and "r9".
+     */
+    #define _syscall5(type,name,type1,arg1,type2,arg2,type3,arg3,type4,arg4,  \
+                      type5,arg5)                                             \
+      type LSS_NAME(name)(type1 arg1, type2 arg2, type3 arg3, type4 arg4,     \
+                          type5 arg5) {                                       \
+        LSS_REG(4, arg1); LSS_REG(5, arg2); LSS_REG(6, arg3);                 \
+        LSS_REG(7, arg4);                                                     \
+        register unsigned long __v0 __asm__("$2") = __NR_##name;              \
+        __asm__ __volatile__ (".set noreorder\n"                              \
+                              "subu  $29, 32\n"                               \
+                              "sw    %5, 16($29)\n"                           \
+                              "syscall\n"                                     \
+                              "addiu $29, 32\n"                               \
+                              ".set reorder\n"                                \
+                              : "+r"(__v0), "+r" (__r7)                       \
+                              : "r"(__r4), "r"(__r5),                         \
+                                "r"(__r6), "r" ((unsigned long)arg5)          \
+                              : "$8", "$9", "$10", "$11", "$12",              \
+                                "$13", "$14", "$15", "$24", "$25",            \
+                                "memory");                                    \
+        LSS_RETURN(type, __v0, __r7);                                         \
+      }
+    #else
+    #define _syscall5(type,name,type1,arg1,type2,arg2,type3,arg3,type4,arg4,  \
+                      type5,arg5)                                             \
+      type LSS_NAME(name)(type1 arg1, type2 arg2, type3 arg3, type4 arg4,     \
+                          type5 arg5) {                                       \
+        LSS_REG(4, arg1); LSS_REG(5, arg2); LSS_REG(6, arg3);                 \
+        LSS_REG(7, arg4); LSS_REG(8, arg5);                                   \
+        LSS_BODY(type, name, "+r", "r"(__r4), "r"(__r5), "r"(__r6),           \
+                 "r"(__r8));                                                  \
+      }
+    #endif
+    #undef _syscall6
+    #if _MIPS_SIM == _MIPS_SIM_ABI32
+    /* The old 32bit MIPS system call API passes the fifth and sixth argument
+     * on the stack, whereas the new APIs use registers "r8" and "r9".
+     */
+    #define _syscall6(type,name,type1,arg1,type2,arg2,type3,arg3,type4,arg4,  \
+                      type5,arg5,type6,arg6)                                  \
+      type LSS_NAME(name)(type1 arg1, type2 arg2, type3 arg3, type4 arg4,     \
+                          type5 arg5, type6 arg6) {                           \
+        LSS_REG(4, arg1); LSS_REG(5, arg2); LSS_REG(6, arg3);                 \
+        LSS_REG(7, arg4);                                                     \
+        register unsigned long __v0 __asm__("$2") = __NR_##name;              \
+        __asm__ __volatile__ (".set noreorder\n"                              \
+                              "subu  $29, 32\n"                               \
+                              "sw    %5, 16($29)\n"                           \
+                              "sw    %6, 20($29)\n"                           \
+                              "syscall\n"                                     \
+                              "addiu $29, 32\n"                               \
+                              ".set reorder\n"                                \
+                              : "+r"(__v0), "+r" (__r7)                       \
+                              : "r"(__r4), "r"(__r5),                         \
+                                "r"(__r6), "r" ((unsigned long)arg5),         \
+                                "r" ((unsigned long)arg6)                     \
+                              : "$8", "$9", "$10", "$11", "$12",              \
+                                "$13", "$14", "$15", "$24", "$25",            \
+                                "memory");                                    \
+        LSS_RETURN(type, __v0, __r7);                                         \
+      }
+    #else
+    #define _syscall6(type,name,type1,arg1,type2,arg2,type3,arg3,type4,arg4,  \
+                      type5,arg5,type6,arg6)                                  \
+      type LSS_NAME(name)(type1 arg1, type2 arg2, type3 arg3, type4 arg4,     \
+                          type5 arg5,type6 arg6) {                            \
+        LSS_REG(4, arg1); LSS_REG(5, arg2); LSS_REG(6, arg3);                 \
+        LSS_REG(7, arg4); LSS_REG(8, arg5); LSS_REG(9, arg6);                 \
+        LSS_BODY(type, name, "+r", "r"(__r4), "r"(__r5), "r"(__r6),           \
+                 "r"(__r8), "r"(__r9));                                       \
+      }
+    #endif
+    LSS_INLINE int LSS_NAME(clone)(int (*fn)(void *), void *child_stack,
+                                   int flags, void *arg, int *parent_tidptr,
+                                   void *newtls, int *child_tidptr) {
+      register unsigned long __v0 __asm__("$2") = -EINVAL;
+      register unsigned long __r7 __asm__("$7") = (unsigned long)newtls;
+      {
+        register int   __flags __asm__("$4") = flags;
+        register void *__stack __asm__("$5") = child_stack;
+        register void *__ptid  __asm__("$6") = parent_tidptr;
+        register int  *__ctid  __asm__("$8") = child_tidptr;
+        __asm__ __volatile__(
+          #if _MIPS_SIM == _MIPS_SIM_ABI32 && _MIPS_SZPTR == 32
+                             "subu  $29,24\n"
+          #elif _MIPS_SIM == _MIPS_SIM_NABI32
+                             "sub   $29,16\n"
+          #else
+                             "dsubu $29,16\n"
+          #endif
+
+                             /* if (fn == NULL || child_stack == NULL)
+                              *   return -EINVAL;
+                              */
+                             "beqz  %4,1f\n"
+                             "beqz  %5,1f\n"
+
+                             /* Push "arg" and "fn" onto the stack that will be
+                              * used by the child.
+                              */
+          #if _MIPS_SIM == _MIPS_SIM_ABI32 && _MIPS_SZPTR == 32
+                             "subu  %5,32\n"
+                             "sw    %4,0(%5)\n"
+                             "sw    %7,4(%5)\n"
+          #elif _MIPS_SIM == _MIPS_SIM_NABI32
+                             "sub   %5,32\n"
+                             "sw    %4,0(%5)\n"
+                             "sw    %7,8(%5)\n"
+          #else
+                             "dsubu %5,32\n"
+                             "sd    %4,0(%5)\n"
+                             "sd    %7,8(%5)\n"
+          #endif
+
+                             /* $7 = syscall($4 = flags,
+                              *              $5 = child_stack,
+                              *              $6 = parent_tidptr,
+                              *              $7 = newtls,
+                              *              $8 = child_tidptr)
+                              */
+                             "li    $2,%2\n"
+                             "syscall\n"
+
+                             /* if ($7 != 0)
+                              *   return $2;
+                              */
+                             "bnez  $7,1f\n"
+                             "bnez  $2,1f\n"
+
+                             /* In the child, now. Call "fn(arg)".
+                              */
+          #if _MIPS_SIM == _MIPS_SIM_ABI32 && _MIPS_SZPTR == 32
+                            "lw    $25,0($29)\n"
+                            "lw    $4,4($29)\n"
+          #elif _MIPS_SIM == _MIPS_SIM_NABI32
+                            "lw    $25,0($29)\n"
+                            "lw    $4,8($29)\n"
+          #else
+                            "ld    $25,0($29)\n"
+                            "ld    $4,8($29)\n"
+          #endif
+                            "jalr  $25\n"
+
+                             /* Call _exit($2)
+                              */
+                            "move  $4,$2\n"
+                            "li    $2,%3\n"
+                            "syscall\n"
+
+                           "1:\n"
+          #if _MIPS_SIM == _MIPS_SIM_ABI32 && _MIPS_SZPTR == 32
+                             "addu  $29, 24\n"
+          #elif _MIPS_SIM == _MIPS_SIM_NABI32
+                             "add   $29, 16\n"
+          #else
+                             "daddu $29,16\n"
+          #endif
+                             : "+r" (__v0), "+r" (__r7)
+                             : "i"(__NR_clone), "i"(__NR_exit), "r"(fn),
+                               "r"(__stack), "r"(__flags), "r"(arg),
+                               "r"(__ptid), "r"(__ctid)
+                             : "$9", "$10", "$11", "$12", "$13", "$14", "$15",
+                               "$24", "$25", "memory");
+      }
+      LSS_RETURN(int, __v0, __r7);
+    }
+  #elif defined (__PPC__)
+    #undef  LSS_LOADARGS_0
+    #define LSS_LOADARGS_0(name, dummy...)                                    \
+        __sc_0 = __NR_##name
+    #undef  LSS_LOADARGS_1
+    #define LSS_LOADARGS_1(name, arg1)                                        \
+            LSS_LOADARGS_0(name);                                             \
+            __sc_3 = (unsigned long) (arg1)
+    #undef  LSS_LOADARGS_2
+    #define LSS_LOADARGS_2(name, arg1, arg2)                                  \
+            LSS_LOADARGS_1(name, arg1);                                       \
+            __sc_4 = (unsigned long) (arg2)
+    #undef  LSS_LOADARGS_3
+    #define LSS_LOADARGS_3(name, arg1, arg2, arg3)                            \
+            LSS_LOADARGS_2(name, arg1, arg2);                                 \
+            __sc_5 = (unsigned long) (arg3)
+    #undef  LSS_LOADARGS_4
+    #define LSS_LOADARGS_4(name, arg1, arg2, arg3, arg4)                      \
+            LSS_LOADARGS_3(name, arg1, arg2, arg3);                           \
+            __sc_6 = (unsigned long) (arg4)
+    #undef  LSS_LOADARGS_5
+    #define LSS_LOADARGS_5(name, arg1, arg2, arg3, arg4, arg5)                \
+            LSS_LOADARGS_4(name, arg1, arg2, arg3, arg4);                     \
+            __sc_7 = (unsigned long) (arg5)
+    #undef  LSS_LOADARGS_6
+    #define LSS_LOADARGS_6(name, arg1, arg2, arg3, arg4, arg5, arg6)          \
+            LSS_LOADARGS_5(name, arg1, arg2, arg3, arg4, arg5);               \
+            __sc_8 = (unsigned long) (arg6)
+    #undef  LSS_ASMINPUT_0
+    #define LSS_ASMINPUT_0 "0" (__sc_0)
+    #undef  LSS_ASMINPUT_1
+    #define LSS_ASMINPUT_1 LSS_ASMINPUT_0, "1" (__sc_3)
+    #undef  LSS_ASMINPUT_2
+    #define LSS_ASMINPUT_2 LSS_ASMINPUT_1, "2" (__sc_4)
+    #undef  LSS_ASMINPUT_3
+    #define LSS_ASMINPUT_3 LSS_ASMINPUT_2, "3" (__sc_5)
+    #undef  LSS_ASMINPUT_4
+    #define LSS_ASMINPUT_4 LSS_ASMINPUT_3, "4" (__sc_6)
+    #undef  LSS_ASMINPUT_5
+    #define LSS_ASMINPUT_5 LSS_ASMINPUT_4, "5" (__sc_7)
+    #undef  LSS_ASMINPUT_6
+    #define LSS_ASMINPUT_6 LSS_ASMINPUT_5, "6" (__sc_8)
+    #undef  LSS_BODY
+    #define LSS_BODY(nr, type, name, args...)                                 \
+        long __sc_ret, __sc_err;                                              \
+        {                                                                     \
+                        register unsigned long __sc_0 __asm__ ("r0");         \
+                        register unsigned long __sc_3 __asm__ ("r3");         \
+                        register unsigned long __sc_4 __asm__ ("r4");         \
+                        register unsigned long __sc_5 __asm__ ("r5");         \
+                        register unsigned long __sc_6 __asm__ ("r6");         \
+                        register unsigned long __sc_7 __asm__ ("r7");         \
+                        register unsigned long __sc_8 __asm__ ("r8");         \
+                                                                              \
+            LSS_LOADARGS_##nr(name, args);                                    \
+            __asm__ __volatile__                                              \
+                ("sc\n\t"                                                     \
+                 "mfcr %0"                                                    \
+                 : "=&r" (__sc_0),                                            \
+                   "=&r" (__sc_3), "=&r" (__sc_4),                            \
+                   "=&r" (__sc_5), "=&r" (__sc_6),                            \
+                   "=&r" (__sc_7), "=&r" (__sc_8)                             \
+                 : LSS_ASMINPUT_##nr                                          \
+                 : "cr0", "ctr", "memory",                                    \
+                   "r9", "r10", "r11", "r12");                                \
+            __sc_ret = __sc_3;                                                \
+            __sc_err = __sc_0;                                                \
+        }                                                                     \
+        LSS_RETURN(type, __sc_ret, __sc_err)
+    #undef _syscall0
+    #define _syscall0(type, name)                                             \
+       type LSS_NAME(name)(void) {                                            \
+          LSS_BODY(0, type, name);                                            \
+       }
+    #undef _syscall1
+    #define _syscall1(type, name, type1, arg1)                                \
+       type LSS_NAME(name)(type1 arg1) {                                      \
+          LSS_BODY(1, type, name, arg1);                                      \
+       }
+    #undef _syscall2
+    #define _syscall2(type, name, type1, arg1, type2, arg2)                   \
+       type LSS_NAME(name)(type1 arg1, type2 arg2) {                          \
+          LSS_BODY(2, type, name, arg1, arg2);                                \
+       }
+    #undef _syscall3
+    #define _syscall3(type, name, type1, arg1, type2, arg2, type3, arg3)      \
+       type LSS_NAME(name)(type1 arg1, type2 arg2, type3 arg3) {              \
+          LSS_BODY(3, type, name, arg1, arg2, arg3);                          \
+       }
+    #undef _syscall4
+    #define _syscall4(type, name, type1, arg1, type2, arg2, type3, arg3,      \
+                                  type4, arg4)                                \
+       type LSS_NAME(name)(type1 arg1, type2 arg2, type3 arg3, type4 arg4) {  \
+          LSS_BODY(4, type, name, arg1, arg2, arg3, arg4);                    \
+       }
+    #undef _syscall5
+    #define _syscall5(type, name, type1, arg1, type2, arg2, type3, arg3,      \
+                                  type4, arg4, type5, arg5)                   \
+       type LSS_NAME(name)(type1 arg1, type2 arg2, type3 arg3, type4 arg4,    \
+                                               type5 arg5) {                  \
+          LSS_BODY(5, type, name, arg1, arg2, arg3, arg4, arg5);              \
+       }
+    #undef _syscall6
+    #define _syscall6(type, name, type1, arg1, type2, arg2, type3, arg3,      \
+                                  type4, arg4, type5, arg5, type6, arg6)      \
+       type LSS_NAME(name)(type1 arg1, type2 arg2, type3 arg3, type4 arg4,    \
+                                               type5 arg5, type6 arg6) {      \
+          LSS_BODY(6, type, name, arg1, arg2, arg3, arg4, arg5, arg6);        \
+       }
+    /* clone function adapted from glibc 2.3.6 clone.S                       */
+    /* TODO(csilvers): consider wrapping some args up in a struct, like we
+     * do for i386's _syscall6, so we can compile successfully on gcc 2.95
+     */
+    LSS_INLINE int LSS_NAME(clone)(int (*fn)(void *), void *child_stack,
+                                   int flags, void *arg, int *parent_tidptr,
+                                   void *newtls, int *child_tidptr) {
+      long __ret, __err;
+      {
+        register int (*__fn)(void *)    __asm__ ("r8")  = fn;
+        register void *__cstack                 __asm__ ("r4")  = child_stack;
+        register int __flags                    __asm__ ("r3")  = flags;
+        register void * __arg                   __asm__ ("r9")  = arg;
+        register int * __ptidptr                __asm__ ("r5")  = parent_tidptr;
+        register void * __newtls                __asm__ ("r6")  = newtls;
+        register int * __ctidptr                __asm__ ("r7")  = child_tidptr;
+        __asm__ __volatile__(
+            /* check for fn == NULL
+             * and child_stack == NULL
+             */
+            "cmpwi cr0, %6, 0\n\t"
+            "cmpwi cr1, %7, 0\n\t"
+            "cror cr0*4+eq, cr1*4+eq, cr0*4+eq\n\t"
+            "beq- cr0, 1f\n\t"
+
+            /* set up stack frame for child                                  */
+            "clrrwi %7, %7, 4\n\t"
+            "li 0, 0\n\t"
+            "stwu 0, -16(%7)\n\t"
+
+            /* fn, arg, child_stack are saved across the syscall: r28-30     */
+            "mr 28, %6\n\t"
+            "mr 29, %7\n\t"
+            "mr 27, %9\n\t"
+
+            /* syscall                                                       */
+            "li 0, %4\n\t"
+            /* flags already in r3
+             * child_stack already in r4
+             * ptidptr already in r5
+             * newtls already in r6
+             * ctidptr already in r7
+             */
+            "sc\n\t"
+
+            /* Test if syscall was successful                                */
+            "cmpwi cr1, 3, 0\n\t"
+            "crandc cr1*4+eq, cr1*4+eq, cr0*4+so\n\t"
+            "bne- cr1, 1f\n\t"
+
+            /* Do the function call                                          */
+            "mtctr 28\n\t"
+            "mr 3, 27\n\t"
+            "bctrl\n\t"
+
+            /* Call _exit(r3)                                                */
+            "li 0, %5\n\t"
+            "sc\n\t"
+
+            /* Return to parent                                              */
+            "1:\n"
+            "mfcr %1\n\t"
+            "mr %0, 3\n\t"
+              : "=r" (__ret), "=r" (__err)
+              : "0" (-1), "1" (EINVAL),
+                "i" (__NR_clone), "i" (__NR_exit),
+                "r" (__fn), "r" (__cstack), "r" (__flags),
+                "r" (__arg), "r" (__ptidptr), "r" (__newtls),
+                "r" (__ctidptr)
+              : "cr0", "cr1", "memory", "ctr",
+                "r0", "r29", "r27", "r28");
+      }
+      LSS_RETURN(int, __ret, __err);
+    }
+  #elif defined(__s390__)
+    #undef  LSS_REG
+    #define LSS_REG(r, a) register unsigned long __r##r __asm__("r"#r) = (unsigned long) a
+    #undef  LSS_BODY
+    #define LSS_BODY(type, name, args...)                                     \
+        register unsigned long __nr __asm__("r1")                             \
+            = (unsigned long)(__NR_##name);                                   \
+        register long __res_r2 __asm__("r2");                                 \
+        long __res;                                                           \
+        __asm__ __volatile__                                                  \
+            ("svc 0\n\t"                                                      \
+             : "=d"(__res_r2)                                                 \
+             : "d"(__nr), ## args                                             \
+             : "memory");                                                     \
+        __res = __res_r2;                                                     \
+        LSS_RETURN(type, __res)
+    #undef _syscall0
+    #define _syscall0(type, name)                                             \
+       type LSS_NAME(name)(void) {                                            \
+          LSS_BODY(type, name);                                               \
+       }
+    #undef _syscall1
+    #define _syscall1(type, name, type1, arg1)                                \
+       type LSS_NAME(name)(type1 arg1) {                                      \
+          LSS_REG(2, arg1);                                                   \
+          LSS_BODY(type, name, "0"(__r2));                                    \
+       }
+    #undef _syscall2
+    #define _syscall2(type, name, type1, arg1, type2, arg2)                   \
+       type LSS_NAME(name)(type1 arg1, type2 arg2) {                          \
+          LSS_REG(2, arg1); LSS_REG(3, arg2);                                 \
+          LSS_BODY(type, name, "0"(__r2), "d"(__r3));                         \
+       }
+    #undef _syscall3
+    #define _syscall3(type, name, type1, arg1, type2, arg2, type3, arg3)      \
+       type LSS_NAME(name)(type1 arg1, type2 arg2, type3 arg3) {              \
+          LSS_REG(2, arg1); LSS_REG(3, arg2); LSS_REG(4, arg3);               \
+          LSS_BODY(type, name, "0"(__r2), "d"(__r3), "d"(__r4));              \
+       }
+    #undef _syscall4
+    #define _syscall4(type, name, type1, arg1, type2, arg2, type3, arg3,      \
+                                  type4, arg4)                                \
+       type LSS_NAME(name)(type1 arg1, type2 arg2, type3 arg3,                \
+                           type4 arg4) {                                      \
+          LSS_REG(2, arg1); LSS_REG(3, arg2); LSS_REG(4, arg3);               \
+          LSS_REG(5, arg4);                                                   \
+          LSS_BODY(type, name, "0"(__r2), "d"(__r3), "d"(__r4),               \
+                               "d"(__r5));                                    \
+       }
+    #undef _syscall5
+    #define _syscall5(type, name, type1, arg1, type2, arg2, type3, arg3,      \
+                                  type4, arg4, type5, arg5)                   \
+       type LSS_NAME(name)(type1 arg1, type2 arg2, type3 arg3,                \
+                           type4 arg4, type5 arg5) {                          \
+          LSS_REG(2, arg1); LSS_REG(3, arg2); LSS_REG(4, arg3);               \
+          LSS_REG(5, arg4); LSS_REG(6, arg5);                                 \
+          LSS_BODY(type, name, "0"(__r2), "d"(__r3), "d"(__r4),               \
+                               "d"(__r5), "d"(__r6));                         \
+       }
+    #undef _syscall6
+    #define _syscall6(type, name, type1, arg1, type2, arg2, type3, arg3,      \
+                                  type4, arg4, type5, arg5, type6, arg6)      \
+       type LSS_NAME(name)(type1 arg1, type2 arg2, type3 arg3,                \
+                           type4 arg4, type5 arg5, type6 arg6) {              \
+          LSS_REG(2, arg1); LSS_REG(3, arg2); LSS_REG(4, arg3);               \
+          LSS_REG(5, arg4); LSS_REG(6, arg5); LSS_REG(7, arg6);               \
+          LSS_BODY(type, name, "0"(__r2), "d"(__r3), "d"(__r4),               \
+                               "d"(__r5), "d"(__r6), "d"(__r7));              \
+       }
+    LSS_INLINE int LSS_NAME(clone)(int (*fn)(void *), void *child_stack,
+                                   int flags, void *arg, int *parent_tidptr,
+                                   void *newtls, int *child_tidptr) {
+      long __ret;
+      {
+        register int  (*__fn)(void *)    __asm__ ("r1")  = fn;
+        register void  *__cstack         __asm__ ("r2")  = child_stack;
+        register int    __flags          __asm__ ("r3")  = flags;
+        register void  *__arg            __asm__ ("r0")  = arg;
+        register int   *__ptidptr        __asm__ ("r4")  = parent_tidptr;
+        register void  *__newtls         __asm__ ("r6")  = newtls;
+        register int   *__ctidptr        __asm__ ("r5")  = child_tidptr;
+        __asm__ __volatile__ (
+    #ifndef __s390x__
+                                  /* arg already in r0 */
+          "ltr %4, %4\n\t"        /* check fn, which is already in r1 */
+          "jz 1f\n\t"             /* NULL function pointer, return -EINVAL */
+          "ltr %5, %5\n\t"        /* check child_stack, which is already in r2 */
+          "jz 1f\n\t"             /* NULL stack pointer, return -EINVAL */
+                                  /* flags already in r3 */
+                                  /* parent_tidptr already in r4 */
+                                  /* child_tidptr already in r5 */
+                                  /* newtls already in r6 */
+          "svc %2\n\t"            /* invoke clone syscall */
+          "ltr %0,%%r2\n\t"       /* load return code into __ret and test */
+          "jnz 1f\n\t"            /* return to parent if non-zero */
+                                  /* start child thread */
+          "lr %%r2, %7\n\t"       /* set first parameter to void *arg */
+          "ahi %%r15, -96\n\t"    /* make room on the stack for the save area */
+          "xc 0(4,%%r15), 0(%%r15)\n\t"
+          "basr %%r14, %4\n\t"    /* jump to fn */
+          "svc %3\n"              /* invoke exit syscall */
+          "1:\n"
+    #else
+                                  /* arg already in r0 */
+          "ltgr %4, %4\n\t"       /* check fn, which is already in r1 */
+          "jz 1f\n\t"             /* NULL function pointer, return -EINVAL */
+          "ltgr %5, %5\n\t"       /* check child_stack, which is already in r2 */
+          "jz 1f\n\t"             /* NULL stack pointer, return -EINVAL */
+                                  /* flags already in r3 */
+                                  /* parent_tidptr already in r4 */
+                                  /* child_tidptr already in r5 */
+                                  /* newtls already in r6 */
+          "svc %2\n\t"            /* invoke clone syscall */
+          "ltgr %0, %%r2\n\t"     /* load return code into __ret and test */
+          "jnz 1f\n\t"            /* return to parent if non-zero */
+                                  /* start child thread */
+          "lgr %%r2, %7\n\t"      /* set first parameter to void *arg */
+          "aghi %%r15, -160\n\t"  /* make room on the stack for the save area */
+          "xc 0(8,%%r15), 0(%%r15)\n\t"
+          "basr %%r14, %4\n\t"    /* jump to fn */
+          "svc %3\n"              /* invoke exit syscall */
+          "1:\n"
+    #endif
+          : "=r" (__ret)
+          : "0" (-EINVAL), "i" (__NR_clone), "i" (__NR_exit),
+            "d" (__fn), "d" (__cstack), "d" (__flags), "d" (__arg),
+            "d" (__ptidptr), "d" (__newtls), "d" (__ctidptr)
+          : "cc", "r14", "memory"
+        );
+      }
+      LSS_RETURN(int, __ret);
+    }
+  #endif
+  #define __NR__exit   __NR_exit
+  #define __NR__gettid __NR_gettid
+  #define __NR__mremap __NR_mremap
+  LSS_INLINE _syscall1(void *,  brk,             void *,      e)
+  LSS_INLINE _syscall1(int,     chdir,           const char *,p)
+  LSS_INLINE _syscall1(int,     close,           int,         f)
+  LSS_INLINE _syscall2(int,     clock_getres,    int,         c,
+                       struct kernel_timespec*, t)
+  LSS_INLINE _syscall2(int,     clock_gettime,   int,         c,
+                       struct kernel_timespec*, t)
+  LSS_INLINE _syscall1(int,     dup,             int,         f)
+  #if defined(__NR_dup2)
+    // dup2 is polyfilled below when not available.
+    LSS_INLINE _syscall2(int,     dup2,            int,         s,
+                         int,            d)
+  #endif
+  #if defined(__NR_dup3)
+    LSS_INLINE _syscall3(int, dup3,  int, s, int, d, int, f)
+  #endif
+  LSS_INLINE _syscall3(int,     execve,          const char*, f,
+                       const char*const*,a,const char*const*, e)
+  LSS_INLINE _syscall1(int,     _exit,           int,         e)
+  LSS_INLINE _syscall1(int,     exit_group,      int,         e)
+  LSS_INLINE _syscall3(int,     fcntl,           int,         f,
+                       int,            c, long,   a)
+  #if defined(__NR_fork)
+    // fork is polyfilled below when not available.
+    LSS_INLINE _syscall0(pid_t,   fork)
+  #endif
+  LSS_INLINE _syscall2(int,     fstat,           int,         f,
+                      struct kernel_stat*,   b)
+  LSS_INLINE _syscall2(int,     fstatfs,         int,         f,
+                      struct kernel_statfs*, b)
+  #if defined(__x86_64__)
+    /* Need to make sure off_t isn't truncated to 32-bits under x32.  */
+    LSS_INLINE int LSS_NAME(ftruncate)(int f, off_t l) {
+      LSS_BODY(2, int, ftruncate, LSS_SYSCALL_ARG(f), (uint64_t)(l));
+    }
+  #else
+    LSS_INLINE _syscall2(int, ftruncate,           int,         f,
+                         off_t,          l)
+  #endif
+  LSS_INLINE _syscall6(int,     futex,          int*,        u,
+                       int,     o,              int,         v,
+                       struct kernel_timespec*, t,
+                       int*,    u2,             int,         v2)
+  LSS_INLINE _syscall3(int,     getdents,        int,         f,
+                       struct kernel_dirent*, d, int,    c)
+  LSS_INLINE _syscall3(int,     getdents64,      int,         f,
+                      struct kernel_dirent64*, d, int,    c)
+  LSS_INLINE _syscall0(gid_t,   getegid)
+  LSS_INLINE _syscall0(uid_t,   geteuid)
+  #if defined(__NR_getpgrp)
+    LSS_INLINE _syscall0(pid_t,   getpgrp)
+  #endif
+  LSS_INLINE _syscall0(pid_t,   getpid)
+  LSS_INLINE _syscall0(pid_t,   getppid)
+  LSS_INLINE _syscall2(int,     getpriority,     int,         a,
+                       int,            b)
+  LSS_INLINE _syscall3(int,     getresgid,       gid_t *,     r,
+                       gid_t *,         e,       gid_t *,     s)
+  LSS_INLINE _syscall3(int,     getresuid,       uid_t *,     r,
+                       uid_t *,         e,       uid_t *,     s)
+#if !defined(__ARM_EABI__)
+  LSS_INLINE _syscall2(int,     getrlimit,       int,         r,
+                      struct kernel_rlimit*, l)
+#endif
+  LSS_INLINE _syscall1(pid_t,   getsid,          pid_t,       p)
+  LSS_INLINE _syscall0(pid_t,   _gettid)
+  LSS_INLINE _syscall2(pid_t,   gettimeofday,    struct kernel_timeval*, t,
+                       void*, tz)
+  LSS_INLINE _syscall5(int,     setxattr,        const char *,p,
+                       const char *,   n,        const void *,v,
+                       size_t,         s,        int,         f)
+  LSS_INLINE _syscall5(int,     lsetxattr,       const char *,p,
+                       const char *,   n,        const void *,v,
+                       size_t,         s,        int,         f)
+  LSS_INLINE _syscall4(ssize_t, getxattr,        const char *,p,
+                       const char *,   n,        void *,      v, size_t, s)
+  LSS_INLINE _syscall4(ssize_t, lgetxattr,       const char *,p,
+                       const char *,   n,        void *,      v, size_t, s)
+  LSS_INLINE _syscall3(ssize_t, listxattr,       const char *,p,
+                       char *,   l,              size_t,      s)
+  LSS_INLINE _syscall3(ssize_t, llistxattr,      const char *,p,
+                       char *,   l,              size_t,      s)
+  LSS_INLINE _syscall3(int,     ioctl,           int,         d,
+                       int,     r,               void *,      a)
+  LSS_INLINE _syscall2(int,     ioprio_get,      int,         which,
+                       int,     who)
+  LSS_INLINE _syscall3(int,     ioprio_set,      int,         which,
+                       int,     who,             int,         ioprio)
+  LSS_INLINE _syscall2(int,     kill,            pid_t,       p,
+                       int,            s)
+  #if defined(__x86_64__)
+    /* Need to make sure off_t isn't truncated to 32-bits under x32.  */
+    LSS_INLINE off_t LSS_NAME(lseek)(int f, off_t o, int w) {
+      _LSS_BODY(3, off_t, lseek, off_t, LSS_SYSCALL_ARG(f), (uint64_t)(o),
+                                        LSS_SYSCALL_ARG(w));
+    }
+  #else
+    LSS_INLINE _syscall3(off_t,   lseek,           int,         f,
+                         off_t,          o, int,    w)
+  #endif
+  LSS_INLINE _syscall2(int,     munmap,          void*,       s,
+                       size_t,         l)
+  LSS_INLINE _syscall6(long,    move_pages,      pid_t,       p,
+                       unsigned long,  n, void **,g, int *,   d,
+                       int *,          s, int,    f)
+  LSS_INLINE _syscall3(int,     mprotect,        const void *,a,
+                       size_t,         l,        int,         p)
+  LSS_INLINE _syscall5(void*,   _mremap,         void*,       o,
+                       size_t,         os,       size_t,      ns,
+                       unsigned long,  f, void *, a)
+  #if defined(__NR_open)
+    // open is polyfilled below when not available.
+    LSS_INLINE _syscall3(int,     open,            const char*, p,
+                         int,            f, int,    m)
+  #endif
+  #if defined(__NR_poll)
+    // poll is polyfilled below when not available.
+    LSS_INLINE _syscall3(int,     poll,           struct kernel_pollfd*, u,
+                         unsigned int,   n, int,    t)
+  #endif
+  #if defined(__NR_ppoll)
+    LSS_INLINE _syscall5(int, ppoll, struct kernel_pollfd *, u,
+                         unsigned int, n, const struct kernel_timespec *, t,
+                         const struct kernel_sigset_t *, sigmask, size_t, s)
+  #endif
+  LSS_INLINE _syscall5(int,     prctl,           int,         option,
+                       unsigned long,  arg2,
+                       unsigned long,  arg3,
+                       unsigned long,  arg4,
+                       unsigned long,  arg5)
+  LSS_INLINE _syscall4(long,    ptrace,          int,         r,
+                       pid_t,          p, void *, a, void *, d)
+  #if defined(__NR_quotactl)
+    // Defined on x86_64 / i386 only
+    LSS_INLINE _syscall4(int,  quotactl,  int,  cmd,  const char *, special,
+                         int, id, caddr_t, addr)
+  #endif
+  LSS_INLINE _syscall3(ssize_t, read,            int,         f,
+                       void *,         b, size_t, c)
+  #if defined(__NR_readlink)
+    // readlink is polyfilled below when not available.
+    LSS_INLINE _syscall3(int,     readlink,        const char*, p,
+                         char*,          b, size_t, s)
+  #endif
+  #if defined(__NR_readlinkat)
+    LSS_INLINE _syscall4(int, readlinkat, int, d, const char *, p, char *, b,
+                         size_t, s)
+  #endif
+  LSS_INLINE _syscall4(int,     rt_sigaction,    int,         s,
+                       const struct kernel_sigaction*, a,
+                       struct kernel_sigaction*, o, size_t,   c)
+  LSS_INLINE _syscall2(int, rt_sigpending, struct kernel_sigset_t *, s,
+                       size_t,         c)
+  LSS_INLINE _syscall4(int, rt_sigprocmask,      int,         h,
+                       const struct kernel_sigset_t*,  s,
+                       struct kernel_sigset_t*,        o, size_t, c)
+  LSS_INLINE _syscall2(int, rt_sigsuspend,
+                       const struct kernel_sigset_t*, s,  size_t, c)
+  LSS_INLINE _syscall4(int, rt_sigtimedwait, const struct kernel_sigset_t*, s,
+                       siginfo_t*, i, const struct timespec*, t, size_t, c)
+  LSS_INLINE _syscall3(int,     sched_getaffinity,pid_t,      p,
+                       unsigned int,   l, unsigned long *, m)
+  LSS_INLINE _syscall3(int,     sched_setaffinity,pid_t,      p,
+                       unsigned int,   l, unsigned long *, m)
+  LSS_INLINE _syscall0(int,     sched_yield)
+  LSS_INLINE _syscall1(long,    set_tid_address, int *,       t)
+  LSS_INLINE _syscall1(int,     setfsgid,        gid_t,       g)
+  LSS_INLINE _syscall1(int,     setfsuid,        uid_t,       u)
+  LSS_INLINE _syscall1(int,     setuid,          uid_t,       u)
+  LSS_INLINE _syscall1(int,     setgid,          gid_t,       g)
+  LSS_INLINE _syscall2(int,     setpgid,         pid_t,       p,
+                       pid_t,          g)
+  LSS_INLINE _syscall3(int,     setpriority,     int,         a,
+                       int,            b, int,    p)
+  LSS_INLINE _syscall3(int,     setresgid,       gid_t,       r,
+                       gid_t,          e, gid_t,  s)
+  LSS_INLINE _syscall3(int,     setresuid,       uid_t,       r,
+                       uid_t,          e, uid_t,  s)
+  LSS_INLINE _syscall2(int,     setrlimit,       int,         r,
+                       const struct kernel_rlimit*, l)
+  LSS_INLINE _syscall0(pid_t,    setsid)
+  LSS_INLINE _syscall2(int,     sigaltstack,     const stack_t*, s,
+                       const stack_t*, o)
+  #if defined(__NR_sigreturn)
+    LSS_INLINE _syscall1(int,     sigreturn,       unsigned long, u)
+  #endif
+  #if defined(__NR_stat)
+    // stat is polyfilled below when not available.
+    LSS_INLINE _syscall2(int,     stat,            const char*, f,
+                        struct kernel_stat*,   b)
+  #endif
+  LSS_INLINE _syscall2(int,     statfs,          const char*, f,
+                      struct kernel_statfs*, b)
+  LSS_INLINE _syscall3(int,     tgkill,          pid_t,       p,
+                       pid_t,          t, int,            s)
+  LSS_INLINE _syscall2(int,     tkill,           pid_t,       p,
+                       int,            s)
+  #if defined(__NR_unlink)
+    // unlink is polyfilled below when not available.
+    LSS_INLINE _syscall1(int,     unlink,           const char*, f)
+  #endif
+  LSS_INLINE _syscall3(ssize_t, write,            int,        f,
+                       const void *,   b, size_t, c)
+  LSS_INLINE _syscall3(ssize_t, writev,           int,        f,
+                       const struct kernel_iovec*, v, size_t, c)
+  #if defined(__NR_getcpu)
+    LSS_INLINE _syscall3(long, getcpu, unsigned *, cpu,
+                         unsigned *, node, void *, unused)
+  #endif
+  #if defined(__x86_64__) ||                                                  \
+     (defined(__mips__) && _MIPS_SIM != _MIPS_SIM_ABI32)
+    LSS_INLINE _syscall3(int, recvmsg,            int,   s,
+                        struct kernel_msghdr*,     m, int, f)
+    LSS_INLINE _syscall3(int, sendmsg,            int,   s,
+                         const struct kernel_msghdr*, m, int, f)
+    LSS_INLINE _syscall6(int, sendto,             int,   s,
+                         const void*,             m, size_t, l,
+                         int,                     f,
+                         const struct kernel_sockaddr*, a, int, t)
+    LSS_INLINE _syscall2(int, shutdown,           int,   s,
+                         int,                     h)
+    LSS_INLINE _syscall3(int, socket,             int,   d,
+                         int,                     t, int,       p)
+    LSS_INLINE _syscall4(int, socketpair,         int,   d,
+                         int,                     t, int,       p, int*, s)
+  #endif
+  #if defined(__NR_fadvise64)
+    #if defined(__x86_64__)
+    /* Need to make sure loff_t isn't truncated to 32-bits under x32.  */
+    LSS_INLINE int LSS_NAME(fadvise64)(int fd, loff_t offset, loff_t len,
+                                       int advice) {
+      LSS_BODY(4, int, fadvise64, LSS_SYSCALL_ARG(fd), (uint64_t)(offset),
+                                  (uint64_t)(len), LSS_SYSCALL_ARG(advice));
+    }
+    #else
+    LSS_INLINE _syscall4(int, fadvise64,
+                         int, fd, loff_t, offset, loff_t, len, int, advice)
+    #endif
+  #elif defined(__i386__)
+    #define __NR__fadvise64_64 __NR_fadvise64_64
+    LSS_INLINE _syscall6(int, _fadvise64_64, int, fd,
+                         unsigned, offset_lo, unsigned, offset_hi,
+                         unsigned, len_lo, unsigned, len_hi,
+                         int, advice)
+
+    LSS_INLINE int LSS_NAME(fadvise64)(int fd, loff_t offset,
+                                       loff_t len, int advice) {
+      return LSS_NAME(_fadvise64_64)(fd,
+                                     (unsigned)offset, (unsigned)(offset >>32),
+                                     (unsigned)len, (unsigned)(len >> 32),
+                                     advice);
+    }
+
+  #elif defined(__s390__) && !defined(__s390x__)
+    #define __NR__fadvise64_64 __NR_fadvise64_64
+    struct kernel_fadvise64_64_args {
+      int fd;
+      long long offset;
+      long long len;
+      int advice;
+    };
+
+    LSS_INLINE _syscall1(int, _fadvise64_64,
+                         struct kernel_fadvise64_64_args *args)
+
+    LSS_INLINE int LSS_NAME(fadvise64)(int fd, loff_t offset,
+                                       loff_t len, int advice) {
+      struct kernel_fadvise64_64_args args = { fd, offset, len, advice };
+      return LSS_NAME(_fadvise64_64)(&args);
+    }
+  #endif
+  #if defined(__NR_fallocate)
+    #if defined(__x86_64__)
+    /* Need to make sure loff_t isn't truncated to 32-bits under x32.  */
+    LSS_INLINE int LSS_NAME(fallocate)(int f, int mode, loff_t offset,
+                                       loff_t len) {
+      LSS_BODY(4, int, fallocate, LSS_SYSCALL_ARG(f), LSS_SYSCALL_ARG(mode),
+                                  (uint64_t)(offset), (uint64_t)(len));
+    }
+    #elif (defined(__i386__) || (defined(__s390__) && !defined(__s390x__)) \
+           || defined(__ARM_ARCH_3__) || defined(__ARM_EABI__) \
+           || (defined(__mips__) && _MIPS_SIM == _MIPS_SIM_ABI32) \
+           || defined(__PPC__))
+    #define __NR__fallocate __NR_fallocate
+    LSS_INLINE _syscall6(int, _fallocate, int, fd,
+                         int, mode,
+                         unsigned, offset_lo, unsigned, offset_hi,
+                         unsigned, len_lo, unsigned, len_hi)
+
+    LSS_INLINE int LSS_NAME(fallocate)(int fd, int mode,
+                                       loff_t offset, loff_t len) {
+      union { loff_t off; unsigned w[2]; } o = { offset }, l = { len };
+      return LSS_NAME(_fallocate)(fd, mode, o.w[0], o.w[1], l.w[0], l.w[1]);
+    }
+    #else
+    LSS_INLINE _syscall4(int, fallocate,
+                         int, f, int, mode, loff_t, offset, loff_t, len)
+    #endif
+  #endif
+  #if defined(__NR_newfstatat)
+    LSS_INLINE _syscall4(int, newfstatat,         int,   d,
+                         const char *,            p,
+                         struct kernel_stat*,     b, int, f)
+  #endif
+  #if defined(__x86_64__) || defined(__s390x__)
+    LSS_INLINE int LSS_NAME(getresgid32)(gid_t *rgid,
+                                         gid_t *egid,
+                                         gid_t *sgid) {
+      return LSS_NAME(getresgid)(rgid, egid, sgid);
+    }
+
+    LSS_INLINE int LSS_NAME(getresuid32)(uid_t *ruid,
+                                         uid_t *euid,
+                                         uid_t *suid) {
+      return LSS_NAME(getresuid)(ruid, euid, suid);
+    }
+
+    LSS_INLINE int LSS_NAME(setfsgid32)(gid_t gid) {
+      return LSS_NAME(setfsgid)(gid);
+    }
+
+    LSS_INLINE int LSS_NAME(setfsuid32)(uid_t uid) {
+      return LSS_NAME(setfsuid)(uid);
+    }
+
+    LSS_INLINE int LSS_NAME(setresgid32)(gid_t rgid, gid_t egid, gid_t sgid) {
+      return LSS_NAME(setresgid)(rgid, egid, sgid);
+    }
+
+    LSS_INLINE int LSS_NAME(setresuid32)(uid_t ruid, uid_t euid, uid_t suid) {
+      return LSS_NAME(setresuid)(ruid, euid, suid);
+    }
+
+    LSS_INLINE int LSS_NAME(sigaction)(int signum,
+                                       const struct kernel_sigaction *act,
+                                       struct kernel_sigaction *oldact) {
+      #if defined(__x86_64__)
+      /* On x86_64, the kernel requires us to always set our own
+       * SA_RESTORER in order to be able to return from a signal handler.
+       * This function must have a "magic" signature that the "gdb"
+       * (and maybe the kernel?) can recognize.
+       */
+      if (act != NULL && !(act->sa_flags & SA_RESTORER)) {
+        struct kernel_sigaction a = *act;
+        a.sa_flags   |= SA_RESTORER;
+        a.sa_restorer = LSS_NAME(restore_rt)();
+        return LSS_NAME(rt_sigaction)(signum, &a, oldact,
+                                      (KERNEL_NSIG+7)/8);
+      } else
+      #endif
+        return LSS_NAME(rt_sigaction)(signum, act, oldact,
+                                      (KERNEL_NSIG+7)/8);
+    }
+
+    LSS_INLINE int LSS_NAME(sigpending)(struct kernel_sigset_t *set) {
+      return LSS_NAME(rt_sigpending)(set, (KERNEL_NSIG+7)/8);
+    }
+
+    LSS_INLINE int LSS_NAME(sigsuspend)(const struct kernel_sigset_t *set) {
+      return LSS_NAME(rt_sigsuspend)(set, (KERNEL_NSIG+7)/8);
+    }
+  #endif
+  #if defined(__NR_rt_sigprocmask)
+    LSS_INLINE int LSS_NAME(sigprocmask)(int how,
+                                         const struct kernel_sigset_t *set,
+                                         struct kernel_sigset_t *oldset) {
+      return LSS_NAME(rt_sigprocmask)(how, set, oldset, (KERNEL_NSIG+7)/8);
+    }
+  #endif
+  #if defined(__NR_rt_sigtimedwait)
+    LSS_INLINE int LSS_NAME(sigtimedwait)(const struct kernel_sigset_t *set,
+                                          siginfo_t *info,
+                                          const struct timespec *timeout) {
+      return LSS_NAME(rt_sigtimedwait)(set, info, timeout, (KERNEL_NSIG+7)/8);
+    }
+  #endif
+  #if defined(__NR_wait4)
+    LSS_INLINE _syscall4(pid_t, wait4,            pid_t, p,
+                         int*,                    s, int,       o,
+                        struct kernel_rusage*,     r)
+  #endif
+  #if defined(__NR_openat)
+    LSS_INLINE _syscall4(int, openat, int, d, const char *, p, int, f, int, m)
+  #endif
+  #if defined(__NR_unlinkat)
+    LSS_INLINE _syscall3(int, unlinkat, int, d, const char *, p, int, f)
+  #endif
+  #if defined(__i386__) || defined(__ARM_ARCH_3__) || defined(__ARM_EABI__) || \
+      (defined(__s390__) && !defined(__s390x__))
+    #define __NR__getresgid32 __NR_getresgid32
+    #define __NR__getresuid32 __NR_getresuid32
+    #define __NR__setfsgid32  __NR_setfsgid32
+    #define __NR__setfsuid32  __NR_setfsuid32
+    #define __NR__setresgid32 __NR_setresgid32
+    #define __NR__setresuid32 __NR_setresuid32
+#if defined(__ARM_EABI__)
+    LSS_INLINE _syscall2(int,   ugetrlimit,        int,          r,
+                        struct kernel_rlimit*, l)
+#endif
+    LSS_INLINE _syscall3(int,     _getresgid32,    gid_t *,      r,
+                         gid_t *,            e,    gid_t *,      s)
+    LSS_INLINE _syscall3(int,     _getresuid32,    uid_t *,      r,
+                         uid_t *,            e,    uid_t *,      s)
+    LSS_INLINE _syscall1(int,     _setfsgid32,     gid_t,        f)
+    LSS_INLINE _syscall1(int,     _setfsuid32,     uid_t,        f)
+    LSS_INLINE _syscall3(int,     _setresgid32,    gid_t,        r,
+                         gid_t,              e,    gid_t,        s)
+    LSS_INLINE _syscall3(int,     _setresuid32,    uid_t,        r,
+                         uid_t,              e,    uid_t,        s)
+
+    LSS_INLINE int LSS_NAME(getresgid32)(gid_t *rgid,
+                                         gid_t *egid,
+                                         gid_t *sgid) {
+      int rc;
+      if ((rc = LSS_NAME(_getresgid32)(rgid, egid, sgid)) < 0 &&
+          LSS_ERRNO == ENOSYS) {
+        if ((rgid == NULL) || (egid == NULL) || (sgid == NULL)) {
+          return EFAULT;
+        }
+        // Clear the high bits first, since getresgid only sets 16 bits
+        *rgid = *egid = *sgid = 0;
+        rc = LSS_NAME(getresgid)(rgid, egid, sgid);
+      }
+      return rc;
+    }
+
+    LSS_INLINE int LSS_NAME(getresuid32)(uid_t *ruid,
+                                         uid_t *euid,
+                                         uid_t *suid) {
+      int rc;
+      if ((rc = LSS_NAME(_getresuid32)(ruid, euid, suid)) < 0 &&
+          LSS_ERRNO == ENOSYS) {
+        if ((ruid == NULL) || (euid == NULL) || (suid == NULL)) {
+          return EFAULT;
+        }
+        // Clear the high bits first, since getresuid only sets 16 bits
+        *ruid = *euid = *suid = 0;
+        rc = LSS_NAME(getresuid)(ruid, euid, suid);
+      }
+      return rc;
+    }
+
+    LSS_INLINE int LSS_NAME(setfsgid32)(gid_t gid) {
+      int rc;
+      if ((rc = LSS_NAME(_setfsgid32)(gid)) < 0 &&
+          LSS_ERRNO == ENOSYS) {
+        if ((unsigned int)gid & ~0xFFFFu) {
+          rc = EINVAL;
+        } else {
+          rc = LSS_NAME(setfsgid)(gid);
+        }
+      }
+      return rc;
+    }
+
+    LSS_INLINE int LSS_NAME(setfsuid32)(uid_t uid) {
+      int rc;
+      if ((rc = LSS_NAME(_setfsuid32)(uid)) < 0 &&
+          LSS_ERRNO == ENOSYS) {
+        if ((unsigned int)uid & ~0xFFFFu) {
+          rc = EINVAL;
+        } else {
+          rc = LSS_NAME(setfsuid)(uid);
+        }
+      }
+      return rc;
+    }
+
+    LSS_INLINE int LSS_NAME(setresgid32)(gid_t rgid, gid_t egid, gid_t sgid) {
+      int rc;
+      if ((rc = LSS_NAME(_setresgid32)(rgid, egid, sgid)) < 0 &&
+          LSS_ERRNO == ENOSYS) {
+        if ((unsigned int)rgid & ~0xFFFFu ||
+            (unsigned int)egid & ~0xFFFFu ||
+            (unsigned int)sgid & ~0xFFFFu) {
+          rc = EINVAL;
+        } else {
+          rc = LSS_NAME(setresgid)(rgid, egid, sgid);
+        }
+      }
+      return rc;
+    }
+
+    LSS_INLINE int LSS_NAME(setresuid32)(uid_t ruid, uid_t euid, uid_t suid) {
+      int rc;
+      if ((rc = LSS_NAME(_setresuid32)(ruid, euid, suid)) < 0 &&
+          LSS_ERRNO == ENOSYS) {
+        if ((unsigned int)ruid & ~0xFFFFu ||
+            (unsigned int)euid & ~0xFFFFu ||
+            (unsigned int)suid & ~0xFFFFu) {
+          rc = EINVAL;
+        } else {
+          rc = LSS_NAME(setresuid)(ruid, euid, suid);
+        }
+      }
+      return rc;
+    }
+  #endif
+  LSS_INLINE int LSS_NAME(sigemptyset)(struct kernel_sigset_t *set) {
+    memset(&set->sig, 0, sizeof(set->sig));
+    return 0;
+  }
+
+  LSS_INLINE int LSS_NAME(sigfillset)(struct kernel_sigset_t *set) {
+    memset(&set->sig, -1, sizeof(set->sig));
+    return 0;
+  }
+
+  LSS_INLINE int LSS_NAME(sigaddset)(struct kernel_sigset_t *set,
+                                     int signum) {
+    if (signum < 1 || signum > (int)(8*sizeof(set->sig))) {
+      LSS_ERRNO = EINVAL;
+      return -1;
+    } else {
+      set->sig[(signum - 1)/(8*sizeof(set->sig[0]))]
+          |= 1UL << ((signum - 1) % (8*sizeof(set->sig[0])));
+      return 0;
+    }
+  }
+
+  LSS_INLINE int LSS_NAME(sigdelset)(struct kernel_sigset_t *set,
+                                        int signum) {
+    if (signum < 1 || signum > (int)(8*sizeof(set->sig))) {
+      LSS_ERRNO = EINVAL;
+      return -1;
+    } else {
+      set->sig[(signum - 1)/(8*sizeof(set->sig[0]))]
+          &= ~(1UL << ((signum - 1) % (8*sizeof(set->sig[0]))));
+      return 0;
+    }
+  }
+
+  LSS_INLINE int LSS_NAME(sigismember)(struct kernel_sigset_t *set,
+                                          int signum) {
+    if (signum < 1 || signum > (int)(8*sizeof(set->sig))) {
+      LSS_ERRNO = EINVAL;
+      return -1;
+    } else {
+      return !!(set->sig[(signum - 1)/(8*sizeof(set->sig[0]))] &
+                (1UL << ((signum - 1) % (8*sizeof(set->sig[0])))));
+    }
+  }
+  #if defined(__i386__) ||                                                    \
+      defined(__ARM_ARCH_3__) || defined(__ARM_EABI__) ||                     \
+     (defined(__mips__) && _MIPS_SIM == _MIPS_SIM_ABI32) ||                   \
+      defined(__PPC__) ||                                                     \
+     (defined(__s390__) && !defined(__s390x__))
+    #define __NR__sigaction   __NR_sigaction
+    #define __NR__sigpending  __NR_sigpending
+    #define __NR__sigsuspend  __NR_sigsuspend
+    #define __NR__socketcall  __NR_socketcall
+    LSS_INLINE _syscall2(int, fstat64,             int, f,
+                         struct kernel_stat64 *, b)
+    LSS_INLINE _syscall5(int, _llseek,     uint, fd,
+                         unsigned long, hi, unsigned long, lo,
+                         loff_t *, res, uint, wh)
+#if defined(__s390__) && !defined(__s390x__)
+    /* On s390, mmap2() arguments are passed in memory. */
+    LSS_INLINE void* LSS_NAME(_mmap2)(void *s, size_t l, int p, int f, int d,
+                                      off_t o) {
+      unsigned long buf[6] = { (unsigned long) s, (unsigned long) l,
+                               (unsigned long) p, (unsigned long) f,
+                               (unsigned long) d, (unsigned long) o };
+      LSS_REG(2, buf);
+      LSS_BODY(void*, mmap2, "0"(__r2));
+    }
+#else
+    #define __NR__mmap2 __NR_mmap2
+    LSS_INLINE _syscall6(void*, _mmap2,            void*, s,
+                         size_t,                   l, int,               p,
+                         int,                      f, int,               d,
+                         off_t,                    o)
+#endif
+    LSS_INLINE _syscall3(int,   _sigaction,        int,   s,
+                         const struct kernel_old_sigaction*,  a,
+                         struct kernel_old_sigaction*,        o)
+    LSS_INLINE _syscall1(int,   _sigpending, unsigned long*, s)
+    #ifdef __PPC__
+    LSS_INLINE _syscall1(int, _sigsuspend,         unsigned long, s)
+    #else
+    LSS_INLINE _syscall3(int, _sigsuspend,         const void*, a,
+                         int,                      b,
+                         unsigned long,            s)
+    #endif
+    LSS_INLINE _syscall2(int, stat64,              const char *, p,
+                         struct kernel_stat64 *, b)
+
+    LSS_INLINE int LSS_NAME(sigaction)(int signum,
+                                       const struct kernel_sigaction *act,
+                                       struct kernel_sigaction *oldact) {
+      int old_errno = LSS_ERRNO;
+      int rc;
+      struct kernel_sigaction a;
+      if (act != NULL) {
+        a             = *act;
+        #ifdef __i386__
+        /* On i386, the kernel requires us to always set our own
+         * SA_RESTORER when using realtime signals. Otherwise, it does not
+         * know how to return from a signal handler. This function must have
+         * a "magic" signature that the "gdb" (and maybe the kernel?) can
+         * recognize.
+         * Apparently, a SA_RESTORER is implicitly set by the kernel, when
+         * using non-realtime signals.
+         *
+         * TODO: Test whether ARM needs a restorer
+         */
+        if (!(a.sa_flags & SA_RESTORER)) {
+          a.sa_flags   |= SA_RESTORER;
+          a.sa_restorer = (a.sa_flags & SA_SIGINFO)
+                          ? LSS_NAME(restore_rt)() : LSS_NAME(restore)();
+        }
+        #endif
+      }
+      rc = LSS_NAME(rt_sigaction)(signum, act ? &a : act, oldact,
+                                  (KERNEL_NSIG+7)/8);
+      if (rc < 0 && LSS_ERRNO == ENOSYS) {
+        struct kernel_old_sigaction oa, ooa, *ptr_a = &oa, *ptr_oa = &ooa;
+        if (!act) {
+          ptr_a            = NULL;
+        } else {
+          oa.sa_handler_   = act->sa_handler_;
+          memcpy(&oa.sa_mask, &act->sa_mask, sizeof(oa.sa_mask));
+          #ifndef __mips__
+          oa.sa_restorer   = act->sa_restorer;
+          #endif
+          oa.sa_flags      = act->sa_flags;
+        }
+        if (!oldact) {
+          ptr_oa           = NULL;
+        }
+        LSS_ERRNO = old_errno;
+        rc = LSS_NAME(_sigaction)(signum, ptr_a, ptr_oa);
+        if (rc == 0 && oldact) {
+          if (act) {
+            memcpy(oldact, act, sizeof(*act));
+          } else {
+            memset(oldact, 0, sizeof(*oldact));
+          }
+          oldact->sa_handler_    = ptr_oa->sa_handler_;
+          oldact->sa_flags       = ptr_oa->sa_flags;
+          memcpy(&oldact->sa_mask, &ptr_oa->sa_mask, sizeof(ptr_oa->sa_mask));
+          #ifndef __mips__
+          oldact->sa_restorer    = ptr_oa->sa_restorer;
+          #endif
+        }
+      }
+      return rc;
+    }
+
+    LSS_INLINE int LSS_NAME(sigpending)(struct kernel_sigset_t *set) {
+      int old_errno = LSS_ERRNO;
+      int rc = LSS_NAME(rt_sigpending)(set, (KERNEL_NSIG+7)/8);
+      if (rc < 0 && LSS_ERRNO == ENOSYS) {
+        LSS_ERRNO = old_errno;
+        LSS_NAME(sigemptyset)(set);
+        rc = LSS_NAME(_sigpending)(&set->sig[0]);
+      }
+      return rc;
+    }
+
+    LSS_INLINE int LSS_NAME(sigsuspend)(const struct kernel_sigset_t *set) {
+      int olderrno = LSS_ERRNO;
+      int rc = LSS_NAME(rt_sigsuspend)(set, (KERNEL_NSIG+7)/8);
+      if (rc < 0 && LSS_ERRNO == ENOSYS) {
+        LSS_ERRNO = olderrno;
+        rc = LSS_NAME(_sigsuspend)(
+        #ifndef __PPC__
+                                   set, 0,
+        #endif
+                                   set->sig[0]);
+      }
+      return rc;
+    }
+  #endif
+  #if defined(__i386__) ||                                                    \
+      defined(__ARM_ARCH_3__) || defined(__ARM_EABI__) ||                     \
+     (defined(__mips__) && _MIPS_SIM == _MIPS_SIM_ABI32) ||                   \
+      defined(__PPC__) ||                                                     \
+     (defined(__s390__) && !defined(__s390x__))
+    /* On these architectures, implement mmap() with mmap2(). */
+    LSS_INLINE void* LSS_NAME(mmap)(void *s, size_t l, int p, int f, int d,
+                                    int64_t o) {
+      if (o % 4096) {
+        LSS_ERRNO = EINVAL;
+        return (void *) -1;
+      }
+      return LSS_NAME(_mmap2)(s, l, p, f, d, (o / 4096));
+    }
+  #elif defined(__s390x__)
+    /* On s390x, mmap() arguments are passed in memory. */
+    LSS_INLINE void* LSS_NAME(mmap)(void *s, size_t l, int p, int f, int d,
+                                    int64_t o) {
+      unsigned long buf[6] = { (unsigned long) s, (unsigned long) l,
+                               (unsigned long) p, (unsigned long) f,
+                               (unsigned long) d, (unsigned long) o };
+      LSS_REG(2, buf);
+      LSS_BODY(void*, mmap, "0"(__r2));
+    }
+  #elif defined(__x86_64__)
+    /* Need to make sure __off64_t isn't truncated to 32-bits under x32.  */
+    LSS_INLINE void* LSS_NAME(mmap)(void *s, size_t l, int p, int f, int d,
+                                    int64_t o) {
+      LSS_BODY(6, void*, mmap, LSS_SYSCALL_ARG(s), LSS_SYSCALL_ARG(l),
+                               LSS_SYSCALL_ARG(p), LSS_SYSCALL_ARG(f),
+                               LSS_SYSCALL_ARG(d), (uint64_t)(o));
+    }
+  #else
+    /* Remaining 64-bit architectures. */
+    LSS_INLINE _syscall6(void*, mmap, void*, addr, size_t, length, int, prot,
+                         int, flags, int, fd, int64_t, offset)
+  #endif
+  #if defined(__PPC__)
+    #undef LSS_SC_LOADARGS_0
+    #define LSS_SC_LOADARGS_0(dummy...)
+    #undef LSS_SC_LOADARGS_1
+    #define LSS_SC_LOADARGS_1(arg1)                                           \
+        __sc_4  = (unsigned long) (arg1)
+    #undef LSS_SC_LOADARGS_2
+    #define LSS_SC_LOADARGS_2(arg1, arg2)                                     \
+        LSS_SC_LOADARGS_1(arg1);                                              \
+        __sc_5  = (unsigned long) (arg2)
+    #undef LSS_SC_LOADARGS_3
+    #define LSS_SC_LOADARGS_3(arg1, arg2, arg3)                               \
+        LSS_SC_LOADARGS_2(arg1, arg2);                                        \
+        __sc_6  = (unsigned long) (arg3)
+    #undef LSS_SC_LOADARGS_4
+    #define LSS_SC_LOADARGS_4(arg1, arg2, arg3, arg4)                         \
+        LSS_SC_LOADARGS_3(arg1, arg2, arg3);                                  \
+        __sc_7  = (unsigned long) (arg4)
+    #undef LSS_SC_LOADARGS_5
+    #define LSS_SC_LOADARGS_5(arg1, arg2, arg3, arg4, arg5)                   \
+        LSS_SC_LOADARGS_4(arg1, arg2, arg3, arg4);                            \
+        __sc_8  = (unsigned long) (arg5)
+    #undef LSS_SC_BODY
+    #define LSS_SC_BODY(nr, type, opt, args...)                               \
+        long __sc_ret, __sc_err;                                              \
+        {                                                                     \
+          register unsigned long __sc_0 __asm__ ("r0") = __NR_socketcall;     \
+          register unsigned long __sc_3 __asm__ ("r3") = opt;                 \
+          register unsigned long __sc_4 __asm__ ("r4");                       \
+          register unsigned long __sc_5 __asm__ ("r5");                       \
+          register unsigned long __sc_6 __asm__ ("r6");                       \
+          register unsigned long __sc_7 __asm__ ("r7");                       \
+          register unsigned long __sc_8 __asm__ ("r8");                       \
+          LSS_SC_LOADARGS_##nr(args);                                         \
+          __asm__ __volatile__                                                \
+              ("stwu 1, -48(1)\n\t"                                           \
+               "stw 4, 20(1)\n\t"                                             \
+               "stw 5, 24(1)\n\t"                                             \
+               "stw 6, 28(1)\n\t"                                             \
+               "stw 7, 32(1)\n\t"                                             \
+               "stw 8, 36(1)\n\t"                                             \
+               "addi 4, 1, 20\n\t"                                            \
+               "sc\n\t"                                                       \
+               "mfcr %0"                                                      \
+                 : "=&r" (__sc_0),                                            \
+                   "=&r" (__sc_3), "=&r" (__sc_4),                            \
+                   "=&r" (__sc_5), "=&r" (__sc_6),                            \
+                   "=&r" (__sc_7), "=&r" (__sc_8)                             \
+                 : LSS_ASMINPUT_##nr                                          \
+                 : "cr0", "ctr", "memory");                                   \
+          __sc_ret = __sc_3;                                                  \
+          __sc_err = __sc_0;                                                  \
+        }                                                                     \
+        LSS_RETURN(type, __sc_ret, __sc_err)
+
+    LSS_INLINE ssize_t LSS_NAME(recvmsg)(int s,struct kernel_msghdr *msg,
+                                         int flags){
+      LSS_SC_BODY(3, ssize_t, 17, s, msg, flags);
+    }
+
+    LSS_INLINE ssize_t LSS_NAME(sendmsg)(int s,
+                                         const struct kernel_msghdr *msg,
+                                         int flags) {
+      LSS_SC_BODY(3, ssize_t, 16, s, msg, flags);
+    }
+
+    // TODO(csilvers): why is this ifdef'ed out?
+#if 0
+    LSS_INLINE ssize_t LSS_NAME(sendto)(int s, const void *buf, size_t len,
+                                        int flags,
+                                        const struct kernel_sockaddr *to,
+                                        unsigned int tolen) {
+      LSS_BODY(6, ssize_t, 11, s, buf, len, flags, to, tolen);
+    }
+#endif
+
+    LSS_INLINE int LSS_NAME(shutdown)(int s, int how) {
+      LSS_SC_BODY(2, int, 13, s, how);
+    }
+
+    LSS_INLINE int LSS_NAME(socket)(int domain, int type, int protocol) {
+      LSS_SC_BODY(3, int, 1, domain, type, protocol);
+    }
+
+    LSS_INLINE int LSS_NAME(socketpair)(int d, int type, int protocol,
+                                        int sv[2]) {
+      LSS_SC_BODY(4, int, 8, d, type, protocol, sv);
+    }
+  #endif
+  #if defined(__ARM_EABI__) || defined (__aarch64__)
+    LSS_INLINE _syscall3(ssize_t, recvmsg, int, s, struct kernel_msghdr*, msg,
+                         int, flags)
+    LSS_INLINE _syscall3(ssize_t, sendmsg, int, s, const struct kernel_msghdr*,
+                         msg, int, flags)
+    LSS_INLINE _syscall6(ssize_t, sendto, int, s, const void*, buf, size_t,len,
+                         int, flags, const struct kernel_sockaddr*, to,
+                         unsigned int, tolen)
+    LSS_INLINE _syscall2(int, shutdown, int, s, int, how)
+    LSS_INLINE _syscall3(int, socket, int, domain, int, type, int, protocol)
+    LSS_INLINE _syscall4(int, socketpair, int, d, int, type, int, protocol,
+                         int*, sv)
+  #endif
+  #if defined(__i386__) || defined(__ARM_ARCH_3__) ||                         \
+      (defined(__mips__) && _MIPS_SIM == _MIPS_SIM_ABI32) ||                  \
+      defined(__s390__)
+    #define __NR__socketcall  __NR_socketcall
+    LSS_INLINE _syscall2(int,      _socketcall,    int,   c,
+                         va_list,                  a)
+    LSS_INLINE int LSS_NAME(socketcall)(int op, ...) {
+      int rc;
+      va_list ap;
+      va_start(ap, op);
+      rc = LSS_NAME(_socketcall)(op, ap);
+      va_end(ap);
+      return rc;
+    }
+
+    LSS_INLINE ssize_t LSS_NAME(recvmsg)(int s,struct kernel_msghdr *msg,
+                                         int flags){
+      return (ssize_t)LSS_NAME(socketcall)(17, s, msg, flags);
+    }
+
+    LSS_INLINE ssize_t LSS_NAME(sendmsg)(int s,
+                                         const struct kernel_msghdr *msg,
+                                         int flags) {
+      return (ssize_t)LSS_NAME(socketcall)(16, s, msg, flags);
+    }
+
+    LSS_INLINE ssize_t LSS_NAME(sendto)(int s, const void *buf, size_t len,
+                                        int flags,
+                                        const struct kernel_sockaddr *to,
+                                        unsigned int tolen) {
+      return (ssize_t)LSS_NAME(socketcall)(11, s, buf, len, flags, to, tolen);
+    }
+
+    LSS_INLINE int LSS_NAME(shutdown)(int s, int how) {
+      return LSS_NAME(socketcall)(13, s, how);
+    }
+
+    LSS_INLINE int LSS_NAME(socket)(int domain, int type, int protocol) {
+      return LSS_NAME(socketcall)(1, domain, type, protocol);
+    }
+
+    LSS_INLINE int LSS_NAME(socketpair)(int d, int type, int protocol,
+                                        int sv[2]) {
+      return LSS_NAME(socketcall)(8, d, type, protocol, sv);
+    }
+  #endif
+  #if defined(__NR_fstatat64)
+    LSS_INLINE _syscall4(int,   fstatat64,        int,   d,
+                         const char *,      p,
+                         struct kernel_stat64 *,   b,    int,   f)
+  #endif
+  #if defined(__NR_waitpid)
+    // waitpid is polyfilled below when not available.
+    LSS_INLINE _syscall3(pid_t, waitpid,          pid_t, p,
+                         int*,              s,    int,   o)
+  #endif
+  #if defined(__mips__)
+    /* sys_pipe() on MIPS has non-standard calling conventions, as it returns
+     * both file handles through CPU registers.
+     */
+    LSS_INLINE int LSS_NAME(pipe)(int *p) {
+      register unsigned long __v0 __asm__("$2") = __NR_pipe;
+      register unsigned long __v1 __asm__("$3");
+      register unsigned long __r7 __asm__("$7");
+      __asm__ __volatile__ ("syscall\n"
+                            : "=r"(__v0), "=r"(__v1), "=r" (__r7)
+                            : "0"(__v0)
+                            : "$8", "$9", "$10", "$11", "$12",
+                              "$13", "$14", "$15", "$24", "$25", "memory");
+      if (__r7) {
+        unsigned long __errnovalue = __v0;
+        LSS_ERRNO = __errnovalue;
+        return -1;
+      } else {
+        p[0] = __v0;
+        p[1] = __v1;
+        return 0;
+      }
+    }
+  #elif defined(__NR_pipe)
+    // pipe is polyfilled below when not available.
+    LSS_INLINE _syscall1(int,     pipe,           int *, p)
+  #endif
+  #if defined(__NR_pipe2)
+    LSS_INLINE _syscall2(int, pipe2, int *, pipefd, int, flags)
+  #endif
+  /* TODO(csilvers): see if ppc can/should support this as well              */
+  #if defined(__i386__) || defined(__ARM_ARCH_3__) ||                         \
+      defined(__ARM_EABI__) ||                                                \
+     (defined(__mips__) && _MIPS_SIM != _MIPS_SIM_ABI64) ||                   \
+     (defined(__s390__) && !defined(__s390x__))
+    #define __NR__statfs64  __NR_statfs64
+    #define __NR__fstatfs64 __NR_fstatfs64
+    LSS_INLINE _syscall3(int, _statfs64,     const char*, p,
+                         size_t, s,struct kernel_statfs64*, b)
+    LSS_INLINE _syscall3(int, _fstatfs64,          int,   f,
+                         size_t, s,struct kernel_statfs64*, b)
+    LSS_INLINE int LSS_NAME(statfs64)(const char *p,
+                                     struct kernel_statfs64 *b) {
+      return LSS_NAME(_statfs64)(p, sizeof(*b), b);
+    }
+    LSS_INLINE int LSS_NAME(fstatfs64)(int f,struct kernel_statfs64 *b) {
+      return LSS_NAME(_fstatfs64)(f, sizeof(*b), b);
+    }
+  #endif
+
+  LSS_INLINE int LSS_NAME(execv)(const char *path, const char *const argv[]) {
+    extern char **environ;
+    return LSS_NAME(execve)(path, argv, (const char *const *)environ);
+  }
+
+  LSS_INLINE pid_t LSS_NAME(gettid)(void) {
+    pid_t tid = LSS_NAME(_gettid)();
+    if (tid != -1) {
+      return tid;
+    }
+    return LSS_NAME(getpid)();
+  }
+
+  LSS_INLINE void *LSS_NAME(mremap)(void *old_address, size_t old_size,
+                                    size_t new_size, int flags, ...) {
+    va_list ap;
+    void *new_address, *rc;
+    va_start(ap, flags);
+    new_address = va_arg(ap, void *);
+    rc = LSS_NAME(_mremap)(old_address, old_size, new_size,
+                           flags, new_address);
+    va_end(ap);
+    return rc;
+  }
+
+  LSS_INLINE int LSS_NAME(ptrace_detach)(pid_t pid) {
+    /* PTRACE_DETACH can sometimes forget to wake up the tracee and it
+     * then sends job control signals to the real parent, rather than to
+     * the tracer. We reduce the risk of this happening by starting a
+     * whole new time slice, and then quickly sending a SIGCONT signal
+     * right after detaching from the tracee.
+     *
+     * We use tkill to ensure that we only issue a wakeup for the thread being
+     * detached.  Large multi threaded apps can take a long time in the kernel
+     * processing SIGCONT.
+     */
+    int rc, err;
+    LSS_NAME(sched_yield)();
+    rc = LSS_NAME(ptrace)(PTRACE_DETACH, pid, (void *)0, (void *)0);
+    err = LSS_ERRNO;
+    LSS_NAME(tkill)(pid, SIGCONT);
+    /* Old systems don't have tkill */
+    if (LSS_ERRNO == ENOSYS)
+      LSS_NAME(kill)(pid, SIGCONT);
+    LSS_ERRNO = err;
+    return rc;
+  }
+
+  LSS_INLINE int LSS_NAME(raise)(int sig) {
+    return LSS_NAME(kill)(LSS_NAME(getpid)(), sig);
+  }
+
+  LSS_INLINE int LSS_NAME(setpgrp)(void) {
+    return LSS_NAME(setpgid)(0, 0);
+  }
+
+  #if defined(__x86_64__)
+    /* Need to make sure loff_t isn't truncated to 32-bits under x32.  */
+    LSS_INLINE ssize_t LSS_NAME(pread64)(int f, void *b, size_t c, loff_t o) {
+      LSS_BODY(4, ssize_t, pread64, LSS_SYSCALL_ARG(f), LSS_SYSCALL_ARG(b),
+                                    LSS_SYSCALL_ARG(c), (uint64_t)(o));
+    }
+
+    LSS_INLINE ssize_t LSS_NAME(pwrite64)(int f, const void *b, size_t c,
+                                          loff_t o) {
+      LSS_BODY(4, ssize_t, pwrite64, LSS_SYSCALL_ARG(f), LSS_SYSCALL_ARG(b),
+                                     LSS_SYSCALL_ARG(c), (uint64_t)(o));
+    }
+
+    LSS_INLINE int LSS_NAME(readahead)(int f, loff_t o, unsigned c) {
+      LSS_BODY(3, int, readahead, LSS_SYSCALL_ARG(f), (uint64_t)(o),
+                                  LSS_SYSCALL_ARG(c));
+    }
+  #elif defined(__mips__) && _MIPS_SIM == _MIPS_SIM_ABI64
+    LSS_INLINE _syscall4(ssize_t, pread64,        int,         f,
+                         void *,         b, size_t,   c,
+                         loff_t,         o)
+    LSS_INLINE _syscall4(ssize_t, pwrite64,       int,         f,
+                         const void *,   b, size_t,   c,
+                         loff_t,         o)
+    LSS_INLINE _syscall3(int,     readahead,      int,         f,
+                         loff_t,         o, unsigned, c)
+  #else
+    #define __NR__pread64   __NR_pread64
+    #define __NR__pwrite64  __NR_pwrite64
+    #define __NR__readahead __NR_readahead
+    #if defined(__ARM_EABI__) || defined(__mips__)
+      /* On ARM and MIPS, a 64-bit parameter has to be in an even-odd register
+       * pair. Hence these calls ignore their fourth argument (r3) so that their
+       * fifth and sixth make such a pair (r4,r5).
+       */
+      #define LSS_LLARG_PAD 0,
+      LSS_INLINE _syscall6(ssize_t, _pread64,        int,         f,
+                           void *,         b, size_t, c,
+                           unsigned, skip, unsigned, o1, unsigned, o2)
+      LSS_INLINE _syscall6(ssize_t, _pwrite64,       int,         f,
+                           const void *,   b, size_t, c,
+                           unsigned, skip, unsigned, o1, unsigned, o2)
+      LSS_INLINE _syscall5(int, _readahead,          int,         f,
+                           unsigned,     skip,
+                           unsigned,       o1, unsigned, o2, size_t, c)
+    #else
+      #define LSS_LLARG_PAD
+      LSS_INLINE _syscall5(ssize_t, _pread64,        int,         f,
+                           void *,         b, size_t, c, unsigned, o1,
+                           unsigned, o2)
+      LSS_INLINE _syscall5(ssize_t, _pwrite64,       int,         f,
+                           const void *,   b, size_t, c, unsigned, o1,
+                           long, o2)
+      LSS_INLINE _syscall4(int, _readahead,          int,         f,
+                           unsigned,       o1, unsigned, o2, size_t, c)
+    #endif
+    /* We force 64bit-wide parameters onto the stack, then access each
+     * 32-bit component individually. This guarantees that we build the
+     * correct parameters independent of the native byte-order of the
+     * underlying architecture.
+     */
+    LSS_INLINE ssize_t LSS_NAME(pread64)(int fd, void *buf, size_t count,
+                                         loff_t off) {
+      union { loff_t off; unsigned arg[2]; } o = { off };
+      return LSS_NAME(_pread64)(fd, buf, count,
+                                LSS_LLARG_PAD o.arg[0], o.arg[1]);
+    }
+    LSS_INLINE ssize_t LSS_NAME(pwrite64)(int fd, const void *buf,
+                                          size_t count, loff_t off) {
+      union { loff_t off; unsigned arg[2]; } o = { off };
+      return LSS_NAME(_pwrite64)(fd, buf, count,
+                                 LSS_LLARG_PAD o.arg[0], o.arg[1]);
+    }
+    LSS_INLINE int LSS_NAME(readahead)(int fd, loff_t off, int len) {
+      union { loff_t off; unsigned arg[2]; } o = { off };
+      return LSS_NAME(_readahead)(fd, LSS_LLARG_PAD o.arg[0], o.arg[1], len);
+    }
+  #endif
+#endif
+
+/*
+ * Polyfills for deprecated syscalls.
+ */
+
+#if !defined(__NR_dup2)
+  LSS_INLINE int LSS_NAME(dup2)(int s, int d) {
+    return LSS_NAME(dup3)(s, d, 0);
+  }
+#endif
+
+#if !defined(__NR_open)
+  LSS_INLINE int LSS_NAME(open)(const char *pathname, int flags, int mode) {
+    return LSS_NAME(openat)(AT_FDCWD, pathname, flags, mode);
+  }
+#endif
+
+#if !defined(__NR_unlink)
+  LSS_INLINE int LSS_NAME(unlink)(const char *pathname) {
+    return LSS_NAME(unlinkat)(AT_FDCWD, pathname, 0);
+  }
+#endif
+
+#if !defined(__NR_readlink)
+  LSS_INLINE int LSS_NAME(readlink)(const char *pathname, char *buffer,
+                                    size_t size) {
+    return LSS_NAME(readlinkat)(AT_FDCWD, pathname, buffer, size);
+  }
+#endif
+
+#if !defined(__NR_pipe)
+  LSS_INLINE int LSS_NAME(pipe)(int *pipefd) {
+    return LSS_NAME(pipe2)(pipefd, 0);
+  }
+#endif
+
+#if !defined(__NR_poll)
+  LSS_INLINE int LSS_NAME(poll)(struct kernel_pollfd *fds, unsigned int nfds,
+                                int timeout) {
+   struct kernel_timespec timeout_ts;
+   struct kernel_timespec *timeout_ts_p = NULL;
+
+    if (timeout >= 0) {
+      timeout_ts.tv_sec = timeout / 1000;
+      timeout_ts.tv_nsec = (timeout % 1000) * 1000000;
+      timeout_ts_p = &timeout_ts;
+    }
+    return LSS_NAME(ppoll)(fds, nfds, timeout_ts_p, NULL, 0);
+  }
+#endif
+
+#if !defined(__NR_stat)
+  LSS_INLINE int LSS_NAME(stat)(const char *pathname,
+                                struct kernel_stat *buf) {
+    return LSS_NAME(newfstatat)(AT_FDCWD, pathname, buf, 0);
+  }
+#endif
+
+#if !defined(__NR_waitpid)
+  LSS_INLINE pid_t LSS_NAME(waitpid)(pid_t pid, int *status, int options) {
+    return LSS_NAME(wait4)(pid, status, options, 0);
+  }
+#endif
+
+#if !defined(__NR_fork)
+// TODO: define this in an arch-independant way instead of inlining the clone
+//       syscall body.
+
+# if defined(__aarch64__)
+  LSS_INLINE pid_t LSS_NAME(fork)(void) {
+    // No fork syscall on aarch64 - implement by means of the clone syscall.
+    // Note that this does not reset glibc's cached view of the PID/TID, so
+    // some glibc interfaces might go wrong in the forked subprocess.
+    int flags = SIGCHLD;
+    void *child_stack = NULL;
+    void *parent_tidptr = NULL;
+    void *newtls = NULL;
+    void *child_tidptr = NULL;
+
+    LSS_REG(0, flags);
+    LSS_REG(1, child_stack);
+    LSS_REG(2, parent_tidptr);
+    LSS_REG(3, newtls);
+    LSS_REG(4, child_tidptr);
+    LSS_BODY(pid_t, clone, "r"(__r0), "r"(__r1), "r"(__r2), "r"(__r3),
+             "r"(__r4));
+  }
+# elif defined(__x86_64__)
+  LSS_INLINE pid_t LSS_NAME(fork)(void) {
+    // Android disallows the fork syscall on x86_64 - implement by means of the
+    // clone syscall as above for aarch64.
+    int flags = SIGCHLD;
+    void *child_stack = NULL;
+    void *parent_tidptr = NULL;
+    void *newtls = NULL;
+    void *child_tidptr = NULL;
+
+    LSS_BODY(5, pid_t, clone, LSS_SYSCALL_ARG(flags),
+             LSS_SYSCALL_ARG(child_stack), LSS_SYSCALL_ARG(parent_tidptr),
+             LSS_SYSCALL_ARG(newtls), LSS_SYSCALL_ARG(child_tidptr));
+  }
+# else
+#  error missing fork polyfill for this architecture
+# endif
+#endif
+
+/* These restore the original values of these macros saved by the
+ * corresponding #pragma push_macro near the top of this file. */
+#pragma pop_macro("stat64")
+#pragma pop_macro("fstat64")
+#pragma pop_macro("lstat64")
+#pragma pop_macro("pread64")
+#pragma pop_macro("pwrite64")
+#pragma pop_macro("getdents64")
+
+#if defined(__cplusplus) && !defined(SYS_CPLUSPLUS)
+}
+#endif
+
+#endif
+#endif
diff --git a/src/third_party/linux-syscall-support/tests/Makefile b/src/third_party/linux-syscall-support/tests/Makefile
new file mode 100644
index 0000000..5e37345
--- /dev/null
+++ b/src/third_party/linux-syscall-support/tests/Makefile
@@ -0,0 +1,131 @@
+# Copyright 2018, Google Inc.  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.
+#     * Neither the name of Google Inc. 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 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.
+
+top_srcdir ?= ..
+
+DEF_FLAGS = -g -pipe
+DEF_WFLAGS = -Wall
+CFLAGS ?= $(DEF_FLAGS)
+CXXFLAGS ?= $(DEF_FLAGS)
+CFLAGS += $(DEF_WFLAGS) -Wstrict-prototypes
+CXXFLAGS += $(DEF_WFLAGS)
+CPPFLAGS += -I$(top_srcdir)
+# We use static linking here so that if people run through qemu/etc... by hand,
+# it's a lot easier to run/debug.  Same for strace output.
+LDFLAGS += -static
+
+TESTS = \
+	fallocate \
+	sigtimedwait \
+	unlink \
+
+all: check
+
+%_test: %.c test_skel.h $(top_srcdir)/linux_syscall_support.h
+	$(CC) $(CFLAGS) $(CPPFLAGS) $(LDFLAGS) -o $@ $<
+
+%_test: %.cc test_skel.h $(top_srcdir)/linux_syscall_support.h
+	$(CXX) $(CXXFLAGS) $(CPPFLAGS) $(LDFLAGS) -o $@ $<
+
+%_run: %_test
+	@t=$(@:_run=_test); \
+	echo "./$$t"; \
+	if ! env -i ./$$t; then \
+		env -i strace -f -v ./$$t; \
+		echo "TRY: gdb -q -ex r -ex bt ./$$t"; \
+		exit 1; \
+	fi
+
+ALL_TEST_TARGETS = $(TESTS:=_test)
+compile_tests: $(ALL_TEST_TARGETS)
+
+ALL_RUN_TARGETS = $(TESTS:=_run)
+check: $(ALL_RUN_TARGETS)
+
+# The "tempfile" targets are the names we use with temp files.
+# Clean them out in case some tests crashed in the middle.
+clean:
+	rm -f *~ *.o tempfile.* a.out core $(ALL_TEST_TARGETS)
+
+.SUFFIXES:
+.PHONY: all check clean compile_tests
+.SECONDARY: $(ALL_TEST_TARGETS)
+
+# Try to cross-compile the tests for all our supported arches.  We test with
+# both gcc and clang.  We don't support execution (yet?), but just compiling
+# & linking helps catch common bugs.
+.PHONY: cross compile_cross
+cross_compile:
+	@echo "Running: $(MAKE) $@ CC='$(CC)' CXX='$(CXX)'"; \
+	if (echo '#include <stdio.h>' | $(CC) -x c -c -o /dev/null -) 2>/dev/null; then \
+		$(MAKE) -s clean; \
+		$(MAKE) -k --no-print-directory compile_tests; \
+	else \
+		echo "Skipping $(CC) test: not installed"; \
+	fi; \
+	echo
+
+# The names here are a best effort.  Not easy to probe for.
+cross:
+	@for cc in \
+		"x86_64-pc-linux-gnu-gcc" \
+		"i686-pc-linux-gnu-gcc" \
+		"x86_64-pc-linux-gnu-gcc -mx32" \
+		"armv7a-unknown-linux-gnueabi-gcc -marm -mhard-float" \
+		"armv7a-unknown-linux-gnueabi-gcc -mthumb -mhard-float" \
+		"powerpc-unknown-linux-gnu-gcc" \
+		"aarch64-unknown-linux-gnu-gcc" \
+		"mips64-unknown-linux-gnu-gcc -mabi=64" \
+		"mips64-unknown-linux-gnu-gcc -mabi=32" \
+		"mips64-unknown-linux-gnu-gcc -mabi=n32" \
+		"s390-ibm-linux-gnu-gcc" \
+		"s390x-ibm-linux-gnu-gcc" \
+	; do \
+		cxx=`echo "$$cc" | sed 's:-gcc:-g++:'`; \
+		$(MAKE) --no-print-directory CC="$$cc" CXX="$$cxx" cross_compile; \
+		\
+		sysroot=`$$cc --print-sysroot 2>/dev/null`; \
+		gccdir=`$$cc -print-file-name=libgcc.a 2>/dev/null`; \
+		gccdir=`dirname "$$gccdir"`; \
+		: Skip building for clang for mips/o32 and s390/31-bit until it works.; \
+		case $$cc in \
+			mips64*-mabi=32) continue;; \
+			s390-*) continue;; \
+		esac; \
+		set -- $$cc; \
+		tuple=$${1%-gcc}; \
+		shift; \
+		cc="clang -target $$tuple $$*"; \
+		: Assume the build system is x86_64 based, so ignore the sysroot.; \
+		case $$tuple in \
+			x86_64*) ;; \
+			*) cc="$$cc --sysroot $$sysroot -B$$gccdir -L$$gccdir";; \
+		esac; \
+		cxx=`echo "$$cc" | sed 's:^clang:clang++:'`; \
+		$(MAKE) --no-print-directory CC="$$cc" CXX="$$cxx" cross_compile; \
+	done
diff --git a/src/third_party/linux-syscall-support/tests/README.md b/src/third_party/linux-syscall-support/tests/README.md
new file mode 100644
index 0000000..45af3c3
--- /dev/null
+++ b/src/third_party/linux-syscall-support/tests/README.md
@@ -0,0 +1,52 @@
+# LSS Tests
+
+## Source Layout
+
+The general layout of the tests:
+* [test_skel.h]: Test helpers for common checks/etc...
+* xxx.c: Unittest for the xxx syscall (e.g. `open.c`).
+* [Makefile]: New tests should be registered in the `TESTS` variable.
+
+## Test Guidelines
+
+The unittest itself generally follows the conventions:
+* Written in C (unless a very specific language behavior is needed).
+* You should only need to `#include "test_skel.h"`.  For new system headers, try
+  to add them here rather than copying to exact unittest (if possible).
+  It might slow compilation down slightly, but makes the code easier to manage.
+  Make sure it is included first.
+* Use `assert()` on everything to check return values.
+* Use `sys_xxx()` to access the syscall via LSS (compared to `xxx()` which tends
+  to come from the C library).
+* If you need a tempfile, use `tempfile.XXXXXX` for templates with helpers like
+  `mkstemp`.  Try to clean them up when you're done with them.
+  These will be created in the cwd, but that's fine.
+* Don't worry about trying to verify the kernel/C library API and various edge
+  cases.  The goal of LSS is to make sure that we pass args along correctly to
+  the syscall only.
+* Make sure to leave comments in the test so it's clear what behavior you're
+  trying to verify (and how).
+
+Feel free to extend [test_skel.h] with more helpers if they're useful to more
+than one test.
+
+If you're looking for a simple example, start with [unlink.c](./unlink.c).
+You should be able to copy this over and replace the content of `main()`.
+
+## Running The Tests
+
+Simply run `make`.  This will compile & execute all the tests on your local
+system.  A standard `make clean` will clean up all the objects.
+
+If you need to debug something, then the programs are simply named `xxx_test`
+and can easily be thrown into `gdb ./xxx_test`.
+
+We have rudimentary cross-compile testing via gcc and clang.  Try running
+`make cross` -- for any toolchains you don't have available, it should skip
+things automatically.  This only verifies the compilation & linking stages
+though.
+
+The cross-compilers can be created using <http://crosstool-ng.github.io/>.
+
+[Makefile]: ./Makefile
+[test_skel.h]: ./test_skel.h
diff --git a/src/third_party/linux-syscall-support/tests/fallocate.c b/src/third_party/linux-syscall-support/tests/fallocate.c
new file mode 100644
index 0000000..c156e58
--- /dev/null
+++ b/src/third_party/linux-syscall-support/tests/fallocate.c
@@ -0,0 +1,67 @@
+/* Copyright 2019, Google Inc.  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.
+ *     * Neither the name of Google Inc. 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 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 "test_skel.h"
+
+int main(int argc, char *argv[]) {
+  int fd = 0, mode = 0;
+  loff_t offset = 0, len = 0;
+
+  // Bad file descriptor.
+  fd = -1;
+  assert(sys_fallocate(fd, mode, offset, len) == -1);
+  assert(errno == EBADF);
+
+  char filename[] = "tempfile.XXXXXX";
+  fd = mkstemp(filename);
+  assert(fd >= 0);
+
+  // Invalid len.
+  assert(sys_fallocate(fd, mode, offset, len) == -1);
+  assert(errno == EINVAL);
+
+  // Small offset and length succeeds.
+  len = 4096;
+  assert(sys_fallocate(fd, mode, offset, len) == 0);
+
+  // Large offset succeeds and isn't truncated.
+  offset = 1llu + UINT32_MAX;
+  assert(sys_fallocate(fd, mode , offset, len) == 0);
+
+#if defined(__NR_fstat64)
+  struct kernel_stat64 st;
+  assert(sys_fstat64(fd, &st) == 0);
+#else
+  struct kernel_stat st;
+  assert(sys_fstat(fd, &st) == 0);
+#endif
+  assert(st.st_size == offset + len);
+
+  return 0;
+}
diff --git a/src/third_party/linux-syscall-support/tests/sigtimedwait.c b/src/third_party/linux-syscall-support/tests/sigtimedwait.c
new file mode 100644
index 0000000..ee2f740
--- /dev/null
+++ b/src/third_party/linux-syscall-support/tests/sigtimedwait.c
@@ -0,0 +1,58 @@
+/* Copyright 2019, Google Inc.  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.
+ *     * Neither the name of Google Inc. 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 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 "test_skel.h"
+
+int main(int argc, char *argv[]) {
+
+  struct kernel_sigset_t sigset = {};
+  siginfo_t siginfo = {};
+  struct timespec timeout = {};
+
+  // Invalid timeouts.
+  timeout.tv_sec = -1;
+  assert(sys_sigtimedwait(&sigset, &siginfo, &timeout) == -1);
+  assert(errno == EINVAL);
+
+  // Expired timeouts.
+  timeout.tv_sec = 0;
+  assert(sys_sigtimedwait(&sigset, &siginfo, &timeout) == -1);
+  assert(errno == EAGAIN);
+
+  // Success.
+  const int kTestSignal = SIGCONT;
+  assert(sys_sigemptyset(&sigset) == 0);
+  assert(sys_sigaddset(&sigset, kTestSignal) == 0);
+  assert(sys_sigprocmask(SIG_BLOCK, &sigset, NULL) == 0);
+  assert(raise(kTestSignal) == 0);
+  assert(sys_sigtimedwait(&sigset, &siginfo, &timeout) == kTestSignal);
+  assert(siginfo.si_signo == kTestSignal);
+
+  return 0;
+}
diff --git a/src/third_party/linux-syscall-support/tests/test_skel.h b/src/third_party/linux-syscall-support/tests/test_skel.h
new file mode 100644
index 0000000..9ff0eb3
--- /dev/null
+++ b/src/third_party/linux-syscall-support/tests/test_skel.h
@@ -0,0 +1,70 @@
+/* Copyright 2018, Google Inc.  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.
+ *     * Neither the name of Google Inc. 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 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.
+ */
+
+/*
+ * Make sure it's defined before including anything else.  A number of syscalls
+ * are GNU extensions and rely on being exported by glibc.
+ */
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+
+/*
+ * Make sure the assert checks aren't removed as all the unittests are based
+ * on them.
+ */
+#undef NDEBUG
+
+#include <assert.h>
+#include <fcntl.h>
+#include <sched.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/mman.h>
+#include <sys/prctl.h>
+#include <sys/stat.h>
+#include <sys/vfs.h>
+#include <sys/wait.h>
+
+#include <linux/capability.h>
+
+#include "linux_syscall_support.h"
+
+void assert_buffers_eq_len(const void *buf1, const void *buf2, size_t len) {
+  const uint8_t *u8_1 = (const uint8_t *)buf1;
+  const uint8_t *u8_2 = (const uint8_t *)buf2;
+  size_t i;
+
+  for (i = 0; i < len; ++i) {
+    if (u8_1[i] != u8_2[i])
+      printf("offset %zu: %02x != %02x\n", i, u8_1[i], u8_2[i]);
+  }
+}
+#define assert_buffers_eq(obj1, obj2) assert_buffers_eq_len(obj1, obj2, sizeof(*obj1))
diff --git a/src/third_party/linux-syscall-support/tests/unlink.c b/src/third_party/linux-syscall-support/tests/unlink.c
new file mode 100644
index 0000000..70c8bc9
--- /dev/null
+++ b/src/third_party/linux-syscall-support/tests/unlink.c
@@ -0,0 +1,48 @@
+/* Copyright 2018, Google Inc.  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.
+ *     * Neither the name of Google Inc. 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 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 "test_skel.h"
+
+int main(int argc, char *argv[]) {
+  // Get a unique path to play with.
+  char foo[] = "tempfile.XXXXXX";
+  int fd = mkstemp(foo);
+  assert(fd != -1);
+
+  // Make sure it exists.
+  assert(access(foo, F_OK) == 0);
+
+  // Then delete it.
+  assert(sys_unlink(foo) == 0);
+
+  // Make sure it's gone.
+  assert(access(foo, F_OK) != 0);
+
+  return 0;
+}