Relocate AArch64 from ports to libc.

This patch moves the AArch64 port to the main sysdeps hierarchy.  The
move is essentially:

  git mv ports/sysdeps/aarch64 sysdeps/aarch64
  git mv ports/sysdeps/unix/sysv/linux/aarch64 sysdeps/unix/sysv/linux/aarch64

The README is updated and I've updated ChangeLog.aarch64 along the
lines of the ARM move.  The AArch64 build has been tested to confirm
that there were no changes in objdump -dr output or the shared
objects.

1 files changed, 80 insertions, 0 deletions

diff --git a/sysdeps/unix/sysv/linux/aarch64/sigaction.c b/sysdeps/unix/sysv/linux/aarch64/sigaction.c
new file mode 100644
index 0000000000..418207f68d
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/aarch64/sigaction.c
@@ -0,0 +1,80 @@
+/* Copyright (C) 1997-2014 Free Software Foundation, Inc.
+
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public License as
+   published by the Free Software Foundation; either version 2.1 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <signal.h>
+#include <string.h>
+
+#include <sysdep.h>
+#include <sys/syscall.h>
+
+#include <kernel-features.h>
+
+#define SA_RESTORER	0x04000000
+
+/* The difference here is that the sigaction structure used in the
+   kernel is not the same as we use in the libc.  Therefore we must
+   translate it here.  */
+#include <kernel_sigaction.h>
+
+int
+__libc_sigaction (int sig, const struct sigaction *act, struct sigaction *oact)
+{
+  int result;
+  struct kernel_sigaction kact;
+  struct kernel_sigaction koact;
+
+  if (act)
+    {
+      kact.k_sa_handler = act->sa_handler;
+      memcpy (&kact.sa_mask, &act->sa_mask, sizeof (sigset_t));
+      kact.sa_flags = act->sa_flags;
+#ifdef HAVE_SA_RESTORER
+      if (kact.sa_flags & SA_RESTORER)
+	kact.sa_restorer = act->sa_restorer;
+#endif
+    }
+
+  result = INLINE_SYSCALL (rt_sigaction, 4, sig,
+			   act ? &kact : NULL,
+			   oact ? &koact : NULL, _NSIG / 8);
+  if (result >= 0 || errno != ENOSYS)
+    {
+      if (oact && result >= 0)
+	{
+	  oact->sa_handler = koact.k_sa_handler;
+	  memcpy (&oact->sa_mask, &koact.sa_mask, sizeof (sigset_t));
+	  oact->sa_flags = koact.sa_flags;
+#ifdef HAVE_SA_RESTORER
+	  oact->sa_restorer = koact.sa_restorer;
+#endif
+	}
+    }
+  return result;
+}
+libc_hidden_def (__libc_sigaction)
+
+#ifdef WRAPPER_INCLUDE
+# include WRAPPER_INCLUDE
+#endif
+
+#ifndef LIBC_SIGACTION
+weak_alias (__libc_sigaction, __sigaction)
+libc_hidden_weak (__sigaction)
+weak_alias (__libc_sigaction, sigaction)
+#endif