Squashed 'third_party/elfutils/' content from commit 555e15e

Change-Id: I61cde98949e47e5c8c09c33260de17f30921be79
git-subtree-dir: third_party/elfutils
git-subtree-split: 555e15ebe8bf1eb33d00747173cfc80cc65648a4
diff --git a/backends/ppc_initreg.c b/backends/ppc_initreg.c
new file mode 100644
index 0000000..69d623b
--- /dev/null
+++ b/backends/ppc_initreg.c
@@ -0,0 +1,114 @@
+/* Fetch live process registers from TID.
+   Copyright (C) 2013 Red Hat, Inc.
+   This file is part of elfutils.
+
+   This file is free software; you can redistribute it and/or modify
+   it under the terms of either
+
+     * the GNU Lesser General Public License as published by the Free
+       Software Foundation; either version 3 of the License, or (at
+       your option) any later version
+
+   or
+
+     * the GNU General Public License as published by the Free
+       Software Foundation; either version 2 of the License, or (at
+       your option) any later version
+
+   or both in parallel, as here.
+
+   elfutils 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
+   General Public License for more details.
+
+   You should have received copies of the GNU General Public License and
+   the GNU Lesser General Public License along with this program.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include "system.h"
+#include <stdlib.h>
+#if defined(__powerpc__) && defined(__linux__)
+# include <sys/user.h>
+# include <sys/ptrace.h>
+#endif
+
+#define BACKEND ppc_
+#include "libebl_CPU.h"
+
+bool
+ppc_dwarf_to_regno (Ebl *ebl __attribute__ ((unused)), unsigned *regno)
+{
+  switch (*regno)
+  {
+    case 108:
+      // LR uses both 65 and 108 numbers, there is no consistency for it.
+      *regno = 65;
+      return true;
+    case 0 ... 107:
+    case 109 ... (114 - 1) -1:
+      return true;
+    case 1200 ... 1231:
+      *regno = *regno - 1200 + (114 - 1);
+      return true;
+    default:
+      return false;
+  }
+  abort ();
+}
+
+__typeof (ppc_dwarf_to_regno)
+     ppc64_dwarf_to_regno
+     __attribute__ ((alias ("ppc_dwarf_to_regno")));
+
+bool
+ppc_set_initial_registers_tid (pid_t tid __attribute__ ((unused)),
+			  ebl_tid_registers_t *setfunc __attribute__ ((unused)),
+			       void *arg __attribute__ ((unused)))
+{
+#if !defined(__powerpc__) || !defined(__linux__)
+  return false;
+#else /* __powerpc__ */
+  union
+    {
+      struct pt_regs r;
+      long l[sizeof (struct pt_regs) / sizeof (long)];
+    }
+  user_regs;
+  eu_static_assert (sizeof (struct pt_regs) % sizeof (long) == 0);
+  /* PTRACE_GETREGS is EIO on kernel-2.6.18-308.el5.ppc64.  */
+  errno = 0;
+  for (unsigned regno = 0; regno < sizeof (user_regs) / sizeof (long);
+       regno++)
+    {
+      user_regs.l[regno] = ptrace (PTRACE_PEEKUSER, tid,
+				   (void *) (uintptr_t) (regno
+							 * sizeof (long)),
+				   NULL);
+      if (errno != 0)
+	return false;
+    }
+  const size_t gprs = sizeof (user_regs.r.gpr) / sizeof (*user_regs.r.gpr);
+  Dwarf_Word dwarf_regs[gprs];
+  for (unsigned gpr = 0; gpr < gprs; gpr++)
+    dwarf_regs[gpr] = user_regs.r.gpr[gpr];
+  if (! setfunc (0, gprs, dwarf_regs, arg))
+    return false;
+  dwarf_regs[0] = user_regs.r.link;
+  // LR uses both 65 and 108 numbers, there is no consistency for it.
+  if (! setfunc (65, 1, dwarf_regs, arg))
+    return false;
+  /* Registers like msr, ctr, xer, dar, dsisr etc. are probably irrelevant
+     for CFI.  */
+  dwarf_regs[0] = user_regs.r.nip;
+  return setfunc (-1, 1, dwarf_regs, arg);
+#endif /* __powerpc__ */
+}
+
+__typeof (ppc_set_initial_registers_tid)
+     ppc64_set_initial_registers_tid
+     __attribute__ ((alias ("ppc_set_initial_registers_tid")));