1 files changed, 146 insertions, 0 deletions
diff --git a/src/third_party/unwind/dist/src/s390x/Gstep.c b/src/third_party/unwind/dist/src/s390x/Gstep.c
new file mode 100644
index 00000000000..0b79580b256
--- /dev/null
+++ b/src/third_party/unwind/dist/src/s390x/Gstep.c
@@ -0,0 +1,146 @@
+/* libunwind - a platform-independent unwind library
+   Copyright (C) 2002-2004 Hewlett-Packard Co
+        Contributed by David Mosberger-Tang <davidm@hpl.hp.com>
+
+   Modified for x86_64 by Max Asbock <masbock@us.ibm.com>
+   Modified for s390x by Michael Munday <mike.munday@ibm.com>
+
+This file is part of libunwind.
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.  */
+
+#include "unwind_i.h"
+#include <signal.h>
+
+static int
+s390x_handle_signal_frame (unw_cursor_t *cursor)
+{
+  struct cursor *c = (struct cursor *) cursor;
+  int ret, i;
+  unw_word_t sc_addr, sp, *gprs, *fprs, *psw;
+
+  ret = dwarf_get (&c->dwarf, c->dwarf.loc[UNW_S390X_R15], &sp);
+  if (ret < 0)
+    return ret;
+
+  /* Save the SP and PC to be able to return execution at this point
+     later in time (unw_resume).  */
+  c->sigcontext_sp = sp;
+  c->sigcontext_pc = c->dwarf.ip;
+  switch (c->sigcontext_format)
+    {
+    case S390X_SCF_LINUX_SIGFRAME: /* sigreturn */
+      sc_addr = sp + 160;
+      gprs = ((struct sigcontext*)sc_addr)->sregs->regs.gprs;
+      fprs = (unw_word_t*)((struct sigcontext*)sc_addr)->sregs->fpregs.fprs;
+      psw  = &((struct sigcontext*)sc_addr)->sregs->regs.psw.addr;
+      break;
+    case S390X_SCF_LINUX_RT_SIGFRAME: /* rt_sigreturn */
+      sc_addr = sp + sizeof(siginfo_t) + 8 + 160;
+      gprs = ((ucontext_t*)sc_addr)->uc_mcontext.gregs;
+      fprs = (unw_word_t*)((ucontext_t*)sc_addr)->uc_mcontext.fpregs.fprs;
+      psw  = &((ucontext_t*)sc_addr)->uc_mcontext.psw.addr;
+      break;
+    default:
+      return -UNW_EUNSPEC;
+    }
+
+  c->sigcontext_addr = sc_addr;
+
+  /* Update the dwarf cursor.
+     Set the location of the registers to the corresponding addresses of the
+     uc_mcontext / sigcontext structure contents.  */
+  for (i = UNW_S390X_R0; i <= UNW_S390X_R15; ++i)
+    c->dwarf.loc[i] = DWARF_MEM_LOC (c, (unw_word_t) &gprs[i-UNW_S390X_R0]);
+  for (i = UNW_S390X_F0; i <= UNW_S390X_F15; ++i)
+    c->dwarf.loc[i] = DWARF_MEM_LOC (c, (unw_word_t) &fprs[i-UNW_S390X_F0]);
+
+  c->dwarf.loc[UNW_S390X_IP] = DWARF_MEM_LOC (c, (unw_word_t) psw);
+
+  /* Set SP/CFA and PC/IP.
+     Normally the default CFA on s390x is r15+160. We do not add that offset
+     here because dwarf_step will add the offset.  */
+  dwarf_get (&c->dwarf, c->dwarf.loc[UNW_S390X_R15], &c->dwarf.cfa);
+  dwarf_get (&c->dwarf, c->dwarf.loc[UNW_S390X_IP], &c->dwarf.ip);
+
+  c->dwarf.pi_valid = 0;
+  c->dwarf.use_prev_instr = 0;
+
+  return 1;
+}
+
+int
+unw_step (unw_cursor_t *cursor)
+{
+  struct cursor *c = (struct cursor *) cursor;
+  int ret = 0, val = c->validate, sig;
+
+#if CONSERVATIVE_CHECKS
+  c->validate = 1;
+#endif
+
+  Debug (1, "(cursor=%p, ip=0x%016lx, cfa=0x%016lx)\n",
+         c, c->dwarf.ip, c->dwarf.cfa);
+
+  /* Try DWARF-based unwinding... */
+  c->sigcontext_format = S390X_SCF_NONE;
+  ret = dwarf_step (&c->dwarf);
+
+#if CONSERVATIVE_CHECKS
+  c->validate = val;
+#endif
+
+  if (unlikely (ret == -UNW_ENOINFO))
+    {
+      /* GCC doesn't currently emit debug information for signal
+         trampolines on s390x so we check for them explicitly.
+
+         If there isn't debug information available we could also
+         try using the backchain (if available).
+
+         Other platforms also detect PLT entries here. That's
+         tricky to do reliably on s390x so I've left it out for
+         now.  */
+
+      /* Memory accesses here are quite likely to be unsafe. */
+      c->validate = 1;
+
+      /* Check if this is a signal frame. */
+      sig = unw_is_signal_frame (cursor);
+      if (sig > 0)
+        {
+          c->sigcontext_format = sig;
+          ret = s390x_handle_signal_frame (cursor);
+        }
+      else
+        {
+          c->dwarf.ip = 0;
+          ret = 0;
+        }
+
+      c->validate = val;
+      return ret;
+    }
+
+  if (unlikely (ret > 0 && c->dwarf.ip == 0))
+    return 0;
+
+  return ret;
+}