1 files changed, 78 insertions, 0 deletions
diff --git a/src/third_party/unwind/dist/src/ppc/Gis_signal_frame.c b/src/third_party/unwind/dist/src/ppc/Gis_signal_frame.c
new file mode 100644
index 00000000000..6184dd5d410
--- /dev/null
+++ b/src/third_party/unwind/dist/src/ppc/Gis_signal_frame.c
@@ -0,0 +1,78 @@
+/* libunwind - a platform-independent unwind library
+   Copyright (C) 2006-2007 IBM
+   Contributed by
+     Corey Ashford <cjashfor@us.ibm.com>
+     Jose Flavio Aguilar Paulino <jflavio@br.ibm.com> <joseflavio@gmail.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 <libunwind_i.h>
+
+int
+unw_is_signal_frame (unw_cursor_t * cursor)
+{
+  struct cursor *c = (struct cursor *) cursor;
+  unw_word_t w0, w1, i0, i1, i2, ip;
+  unw_addr_space_t as;
+  unw_accessors_t *a;
+  void *arg;
+  int ret;
+
+  as = c->dwarf.as;
+  as->validate = 1;             /* Don't trust the ip */
+  arg = c->dwarf.as_arg;
+
+  /* Check if return address points at sigreturn sequence.
+     on ppc64 Linux that is (see libc.so):
+     0x38210080  addi r1, r1, 128  // pop the stack
+     0x380000ac  li r0, 172        // invoke system service 172
+     0x44000002  sc
+   */
+
+  ip = c->dwarf.ip;
+  if (ip == 0)
+    return 0;
+
+  /* Read up two 8-byte words at the IP.  We are only looking at 3
+     consecutive 32-bit words, so the second 8-byte word needs to be
+     shifted right by 32 bits (think big-endian) */
+
+  a = unw_get_accessors_int (as);
+  if ((ret = (*a->access_mem) (as, ip, &w0, 0, arg)) < 0
+      || (ret = (*a->access_mem) (as, ip + 8, &w1, 0, arg)) < 0)
+    return 0;
+
+  if (tdep_big_endian (as))
+    {
+      i0 = w0 >> 32;
+      i1 = w0 & 0xffffffffUL;
+      i2 = w1 >> 32;
+    }
+  else
+    {
+      i0 = w0 & 0xffffffffUL;
+      i1 = w0 >> 32;
+      i2 = w1 & 0xffffffffUL;
+    }
+
+  return (i0 == 0x38210080 && i1 == 0x380000ac && i2 == 0x44000002);
+}