1 files changed, 113 insertions, 0 deletions
diff --git a/scripts/gdb/linux/lists.py b/scripts/gdb/linux/lists.py
new file mode 100644
index 000000000..2f335fbd8
--- /dev/null
+++ b/scripts/gdb/linux/lists.py
@@ -0,0 +1,113 @@
+#
+# gdb helper commands and functions for Linux kernel debugging
+#
+#  list tools
+#
+# Copyright (c) Thiebaud Weksteen, 2015
+#
+# Authors:
+#  Thiebaud Weksteen <thiebaud@weksteen.fr>
+#
+# This work is licensed under the terms of the GNU GPL version 2.
+#
+
+import gdb
+
+from linux import utils
+
+list_head = utils.CachedType("struct list_head")
+
+
+def list_for_each(head):
+    if head.type == list_head.get_type().pointer():
+        head = head.dereference()
+    elif head.type != list_head.get_type():
+        raise gdb.GdbError("Must be struct list_head not {}"
+                           .format(head.type))
+
+    node = head['next'].dereference()
+    while node.address != head.address:
+        yield node.address
+        node = node['next'].dereference()
+
+
+def list_for_each_entry(head, gdbtype, member):
+    for node in list_for_each(head):
+        if node.type != list_head.get_type().pointer():
+            raise TypeError("Type {} found. Expected struct list_head *."
+                            .format(node.type))
+        yield utils.container_of(node, gdbtype, member)
+
+
+def list_check(head):
+    nb = 0
+    if (head.type == list_head.get_type().pointer()):
+        head = head.dereference()
+    elif (head.type != list_head.get_type()):
+        raise gdb.GdbError('argument must be of type (struct list_head [*])')
+    c = head
+    try:
+        gdb.write("Starting with: {}\n".format(c))
+    except gdb.MemoryError:
+        gdb.write('head is not accessible\n')
+        return
+    while True:
+        p = c['prev'].dereference()
+        n = c['next'].dereference()
+        try:
+            if p['next'] != c.address:
+                gdb.write('prev.next != current: '
+                          'current@{current_addr}={current} '
+                          'prev@{p_addr}={p}\n'.format(
+                              current_addr=c.address,
+                              current=c,
+                              p_addr=p.address,
+                              p=p,
+                          ))
+                return
+        except gdb.MemoryError:
+            gdb.write('prev is not accessible: '
+                      'current@{current_addr}={current}\n'.format(
+                          current_addr=c.address,
+                          current=c
+                      ))
+            return
+        try:
+            if n['prev'] != c.address:
+                gdb.write('next.prev != current: '
+                          'current@{current_addr}={current} '
+                          'next@{n_addr}={n}\n'.format(
+                              current_addr=c.address,
+                              current=c,
+                              n_addr=n.address,
+                              n=n,
+                          ))
+                return
+        except gdb.MemoryError:
+            gdb.write('next is not accessible: '
+                      'current@{current_addr}={current}\n'.format(
+                          current_addr=c.address,
+                          current=c
+                      ))
+            return
+        c = n
+        nb += 1
+        if c == head:
+            gdb.write("list is consistent: {} node(s)\n".format(nb))
+            return
+
+
+class LxListChk(gdb.Command):
+    """Verify a list consistency"""
+
+    def __init__(self):
+        super(LxListChk, self).__init__("lx-list-check", gdb.COMMAND_DATA,
+                                        gdb.COMPLETE_EXPRESSION)
+
+    def invoke(self, arg, from_tty):
+        argv = gdb.string_to_argv(arg)
+        if len(argv) != 1:
+            raise gdb.GdbError("lx-list-check takes one argument")
+        list_check(gdb.parse_and_eval(argv[0]))
+
+LxListChk()