[PATCH 5/6] Revert "scripts/gdb: add a Radix Tree Parser"

[Kieran Bingham]

This reverts commit e127a73d41ac ("scripts/gdb: add a Radix Tree Parser")

The python implementation of radix-tree was merged at the same time as
the radix-tree system was heavily reworked from commit e9256efcc8e3
("radix-tree: introduce radix_tree_empty") to 3bcadd6fa6c4 ("radix-tree:
free up the bottom bit of exceptional entries for reuse") and no longer
functions, but also prevents other gdb scripts from loading.

This functionality has not yet hit a release, so simply remove it for
now

Signed-off-by: Kieran Bingham <kieran@xxxxxxxxxxx>
---
Due to unfortunate timing, the radix tree python implementation was
merged at the same time as the radix-tree itself was heavily rewritten.
Unfortunately I have not been able to find enough time to rewrite the
python implementation in this rc-window, and as the radix-tree.py has
not yet made it out to a release in a working state, at this point the
best thing to do is to revert it. (It currently causes breakage for the
other gdb scripts

I will then intend to resubmit a new implementation for a later release,
and also we can plan an automated test service for the scripts to catch
these issues earlier.

 scripts/gdb/linux/constants.py.in |  7 ---
 scripts/gdb/linux/radixtree.py    | 97 ---------------------------------------
 scripts/gdb/vmlinux-gdb.py        |  1 -
 3 files changed, 105 deletions(-)
 delete mode 100644 scripts/gdb/linux/radixtree.py

diff --git a/scripts/gdb/linux/constants.py.in b/scripts/gdb/linux/constants.py.in
index 07e6c2befe36..7986f4e0da12 100644
--- a/scripts/gdb/linux/constants.py.in
+++ b/scripts/gdb/linux/constants.py.in
@@ -14,7 +14,6 @@
 
 #include <linux/fs.h>
 #include <linux/mount.h>
-#include <linux/radix-tree.h>
 
 /* We need to stringify expanded macros so that they can be parsed */
 
@@ -51,9 +50,3 @@ LX_VALUE(MNT_NOEXEC)
 LX_VALUE(MNT_NOATIME)
 LX_VALUE(MNT_NODIRATIME)
 LX_VALUE(MNT_RELATIME)
-
-/* linux/radix-tree.h */
-LX_VALUE(RADIX_TREE_INDIRECT_PTR)
-LX_GDBPARSED(RADIX_TREE_HEIGHT_MASK)
-LX_GDBPARSED(RADIX_TREE_MAP_SHIFT)
-LX_GDBPARSED(RADIX_TREE_MAP_MASK)
diff --git a/scripts/gdb/linux/radixtree.py b/scripts/gdb/linux/radixtree.py
deleted file mode 100644
index 0fdef4e2971a..000000000000
--- a/scripts/gdb/linux/radixtree.py
+++ /dev/null
@@ -1,97 +0,0 @@
-#
-# gdb helper commands and functions for Linux kernel debugging
-#
-#  Radix Tree Parser
-#
-# Copyright (c) 2016 Linaro Ltd
-#
-# Authors:
-#  Kieran Bingham <kieran.bingham@xxxxxxxxxx>
-#
-# 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()
diff --git a/scripts/gdb/vmlinux-gdb.py b/scripts/gdb/vmlinux-gdb.py
index 3a80ad6eecad..6e0b0afd888a 100644
--- a/scripts/gdb/vmlinux-gdb.py
+++ b/scripts/gdb/vmlinux-gdb.py
@@ -31,4 +31,3 @@ else:
     import linux.lists
     import linux.proc
     import linux.constants
-    import linux.radixtree
-- 
2.7.4