1 files changed, 95 insertions, 0 deletions
diff --git a/src/backends/s390_initreg.c b/src/backends/s390_initreg.c
new file mode 100644
index 00000000..b4c4b67c
--- /dev/null
+++ b/src/backends/s390_initreg.c
@@ -0,0 +1,95 @@
+/* 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 <assert.h>
+#ifdef __s390__
+# include <sys/user.h>
+# include <asm/ptrace.h>
+# include <sys/ptrace.h>
+#endif
+
+#define BACKEND s390_
+#include "libebl_CPU.h"
+
+bool
+s390_set_initial_registers_tid (pid_t tid __attribute__ ((unused)),
+			  ebl_tid_registers_t *setfunc __attribute__ ((unused)),
+				void *arg __attribute__ ((unused)))
+{
+#ifndef __s390__
+  return false;
+#else /* __s390__ */
+  struct user user_regs;
+  ptrace_area parea;
+  parea.process_addr = (uintptr_t) &user_regs;
+  parea.kernel_addr = 0;
+  parea.len = sizeof (user_regs);
+  if (ptrace (PTRACE_PEEKUSR_AREA, tid, &parea, NULL) != 0)
+    return false;
+  /* If we run as s390x we get the 64-bit registers of tid.
+     But -m31 executable seems to use only the 32-bit parts of its
+     registers so we ignore the upper half.  */
+  Dwarf_Word dwarf_regs[16];
+  for (unsigned u = 0; u < 16; u++)
+    dwarf_regs[u] = user_regs.regs.gprs[u];
+  if (! setfunc (0, 16, dwarf_regs, arg))
+    return false;
+  /* Avoid conversion double -> integer.  */
+  eu_static_assert (sizeof user_regs.regs.fp_regs.fprs[0]
+		    == sizeof dwarf_regs[0]);
+  for (unsigned u = 0; u < 16; u++)
+    {
+      // Store the double bits as is in the Dwarf_Word without conversion.
+      union
+	{
+	  double d;
+	  Dwarf_Word w;
+	} fpr = { .d = user_regs.regs.fp_regs.fprs[u] };
+      dwarf_regs[u] = fpr.w;
+    }
+
+  if (! setfunc (16, 16, dwarf_regs, arg))
+    return false;
+  dwarf_regs[0] = user_regs.regs.psw.addr;
+  return setfunc (-1, 1, dwarf_regs, arg);
+#endif /* __s390__ */
+}
+
+void
+s390_normalize_pc (Ebl *ebl __attribute__ ((unused)), Dwarf_Addr *pc)
+{
+  assert (ebl->class == ELFCLASS32);
+
+  /* Clear S390 bit 31.  */
+  *pc &= (1U << 31) - 1;
+}