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