Merge ssh://master.kernel.org/home/hpa/tree/sec

* ssh://master.kernel.org/home/hpa/tree/sec:
  x86-64, compat: Retruncate rax after ia32 syscall entry tracing
  x86-64, compat: Test %rax for the syscall number, not %eax
  compat: Make compat_alloc_user_space() incorporate the access_ok()