scripts/gdb: add module iteration class

Will soon be used for loading symbols, printing global variables or
listing modules.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ben Widawsky <ben@bwidawsk.net>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

scripts/gdb/linux/modules.py

+#
+# gdb helper commands and functions for Linux kernel debugging
+#
+#  module tools
+#
+# Copyright (c) Siemens AG, 2013
+#
+# Authors:
+#  Jan Kiszka <jan.kiszka@siemens.com>
+#
+# This work is licensed under the terms of the GNU GPL version 2.
+#
+
+import gdb
+
+from linux import utils
+
+
+module_type = utils.CachedType("struct module")
+
+
+class ModuleList:
+    def __init__(self):
+        global module_type
+        self.module_ptr_type = module_type.get_type().pointer()
+        modules = gdb.parse_and_eval("modules")
+        self.curr_entry = modules['next']
+        self.end_of_list = modules.address
+
+    def __iter__(self):
+        return self
+
+    def next(self):
+        entry = self.curr_entry
+        if entry != self.end_of_list:
+            self.curr_entry = entry['next']
+            return utils.container_of(entry, self.module_ptr_type, "list")
+        else:
+            raise StopIteration