98 lines
2.5 KiB
Python
98 lines
2.5 KiB
Python
|
#
|
||
|
|
# gdb helper commands and functions for Linux kernel debugging
|
||
|
|
#
|
||
|
|
# Radix Tree Parser
|
||
|
|
#
|
||
|
|
# Copyright (c) 2016 Linaro Ltd
|
||
|
|
#
|
||
|
|
# Authors:
|
||
|
|
# Kieran Bingham <kieran.bingham@linaro.org>
|
||
|
|
#
|
||
|
|
# This work is licensed under the terms of the GNU GPL version 2.
|
||
|
|
#
|
||
|
|
|
||
|
|
import gdb
|
||
|
|
|
||
|
|
from linux import utils
|
||
|
|
from linux import constants
|
||
|
|
|
||
|
|
radix_tree_root_type = utils.CachedType("struct radix_tree_root")
|
||
|
|
radix_tree_node_type = utils.CachedType("struct radix_tree_node")
|
||
|
|
|
||
|
|
|
||
|
|
def is_indirect_ptr(node):
|
||
|
|
long_type = utils.get_long_type()
|
||
|
|
return (node.cast(long_type) & constants.LX_RADIX_TREE_INDIRECT_PTR)
|
||
|
|
|
||
|
|
|
||
|
|
def indirect_to_ptr(node):
|
||
|
|
long_type = utils.get_long_type()
|
||
|
|
node_type = node.type
|
||
|
|
indirect_ptr = node.cast(long_type) & ~constants.LX_RADIX_TREE_INDIRECT_PTR
|
||
|
|
return indirect_ptr.cast(node_type)
|
||
|
|
|
||
|
|
|
||
|
|
def maxindex(height):
|
||
|
|
height = height & constants.LX_RADIX_TREE_HEIGHT_MASK
|
||
|
|
return gdb.parse_and_eval("height_to_maxindex["+str(height)+"]")
|
||
|
|
|
||
|
|
|
||
|
|
def lookup(root, index):
|
||
|
|
if root.type == radix_tree_root_type.get_type().pointer():
|
||
|
|
root = root.dereference()
|
||
|
|
elif root.type != radix_tree_root_type.get_type():
|
||
|
|
raise gdb.GdbError("Must be struct radix_tree_root not {}"
|
||
|
|
.format(root.type))
|
||
|
|
|
||
|
|
node = root['rnode']
|
||
|
|
if node is 0:
|
||
|
|
return None
|
||
|
|
|
||
|
|
if not (is_indirect_ptr(node)):
|
||
|
|
if (index > 0):
|
||
|
|
return None
|
||
|
|
return node
|
||
|
|
|
||
|
|
node = indirect_to_ptr(node)
|
||
|
|
|
||
|
|
height = node['path'] & constants.LX_RADIX_TREE_HEIGHT_MASK
|
||
|
|
if (index > maxindex(height)):
|
||
|
|
return None
|
||
|
|
|
||
|
|
shift = (height-1) * constants.LX_RADIX_TREE_MAP_SHIFT
|
||
|
|
|
||
|
|
while True:
|
||
|
|
new_index = (index >> shift) & constants.LX_RADIX_TREE_MAP_MASK
|
||
|
|
slot = node['slots'][new_index]
|
||
|
|
|
||
|
|
node = slot.cast(node.type.pointer()).dereference()
|
||
|
|
if node is 0:
|
||
|
|
return None
|
||
|
|
|
||
|
|
shift -= constants.LX_RADIX_TREE_MAP_SHIFT
|
||
|
|
height -= 1
|
||
|
|
|
||
|
|
if (height <= 0):
|
||
|
|
break
|
||
|
|
|
||
|
|
return node
|
||
|
|
|
||
|
|
|
||
|
|
class LxRadixTree(gdb.Function):
|
||
|
|
""" Lookup and return a node from a RadixTree.
|
||
|
|
|
||
|
|
$lx_radix_tree_lookup(root_node [, index]): Return the node at the given index.
|
||
|
|
If index is omitted, the root node is dereferenced and returned."""
|
||
|
|
|
||
|
|
def __init__(self):
|
||
|
|
super(LxRadixTree, self).__init__("lx_radix_tree_lookup")
|
||
|
|
|
||
|
|
def invoke(self, root, index=0):
|
||
|
|
result = lookup(root, index)
|
||
|
|
if result is None:
|
||
|
|
raise gdb.GdbError("No entry in tree at index {}".format(index))
|
||
|
|
|
||
|
|
return result
|
||
|
|
|
||
|
|
LxRadixTree()
|