Adjust ia64_linux_xfer_partial following to_xfer_partial API change.

ia64-linux-nat.c no longer compiles because ia64_linux_xfer_partial
no longer matches the to_xfer_partial prototype.  This patch fixes
the problem by adjusting it accordingly.

gdb/ChangeLog:

        * ia64-linux-nat.c (ia64_linux_xfer_partial): Add function
        documentation.  Adjust prototype to match the target_ops
        to_xfer_partial method.  Adjust implementation accordingly.

2 files changed, 29 insertions, 5 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index d3ae4f2..b2385c1 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,9 @@
+2014-02-25  Joel Brobecker  <brobecker@adacore.com>
+
+	* ia64-linux-nat.c (ia64_linux_xfer_partial): Add function
+	documentation.  Adjust prototype to match the target_ops
+	to_xfer_partial method.  Adjust implementation accordingly.
+
 2014-02-25  Hui Zhu  <hui@codesourcery.com>
 
 	* target.h (target_ops): Fix TARGET_DEFAULT_RETURN of
diff --git a/gdb/ia64-linux-nat.c b/gdb/ia64-linux-nat.c
index ccd55b2..c057b55 100644
--- a/gdb/ia64-linux-nat.c
+++ b/gdb/ia64-linux-nat.c
@@ -838,18 +838,36 @@ ia64_linux_store_registers (struct target_ops *ops,
 
 static target_xfer_partial_ftype *super_xfer_partial;
 
-static LONGEST 
+/* Implement the to_xfer_partial target_ops method.  */
+
+static enum target_xfer_status
 ia64_linux_xfer_partial (struct target_ops *ops,
 			 enum target_object object,
 			 const char *annex,
 			 gdb_byte *readbuf, const gdb_byte *writebuf,
-			 ULONGEST offset, ULONGEST len)
+			 ULONGEST offset, ULONGEST len,
+			 ULONGEST *xfered_len)
 {
-  if (object == TARGET_OBJECT_UNWIND_TABLE && writebuf == NULL && offset == 0)
-    return syscall (__NR_getunwind, readbuf, len);
+  if (object == TARGET_OBJECT_UNWIND_TABLE && readbuf != NULL)
+    {
+      gdb_byte *tmp_buf = alloca (offset + len);
+      ULONGEST xfered;
+
+      xfered = syscall (__NR_getunwind, readbuf, offset + len);
+      if (xfered <= 0)
+	return TARGET_XFER_E_IO;
+      else if (xfered <= offset)
+	return TARGET_XFER_EOF;
+      else
+	{
+	  memcpy (readbuf, tmp_buf + offset, xfered - offset);
+	  *xfered_len = xfered - offset;
+	  return TARGET_XFER_OK;
+	}
+    }
 
   return super_xfer_partial (ops, object, annex, readbuf, writebuf,
-			     offset, len);
+			     offset, len, xfered_len);
 }
 
 /* For break.b instruction ia64 CPU forgets the immediate value and generates