1# SPDX-License-Identifier: GPL-2.0
2#
3# Copyright 2024 Canonical Ltd.
4#
5# Authors:
6#  Kuan-Ying Lee <kuan-ying.lee@canonical.com>
7#
8
9import gdb
10from linux import constants, mm
11
12def help():
13    t = """Usage: lx-kasan_mem_to_shadow [Hex memory addr]
14    Example:
15        lx-kasan_mem_to_shadow 0xffff000008eca008\n"""
16    gdb.write("Unrecognized command\n")
17    raise gdb.GdbError(t)
18
19class KasanMemToShadow(gdb.Command):
20    """Translate memory address to kasan shadow address"""
21
22    p_ops = None
23
24    def __init__(self):
25        if constants.LX_CONFIG_KASAN_GENERIC or constants.LX_CONFIG_KASAN_SW_TAGS:
26            super(KasanMemToShadow, self).__init__("lx-kasan_mem_to_shadow", gdb.COMMAND_SUPPORT)
27
28    def invoke(self, args, from_tty):
29        if not constants.LX_CONFIG_KASAN_GENERIC or constants.LX_CONFIG_KASAN_SW_TAGS:
30            raise gdb.GdbError('CONFIG_KASAN_GENERIC or CONFIG_KASAN_SW_TAGS is not set')
31
32        argv = gdb.string_to_argv(args)
33        if len(argv) == 1:
34            if self.p_ops is None:
35                self.p_ops = mm.page_ops().ops
36            addr = int(argv[0], 16)
37            shadow_addr = self.kasan_mem_to_shadow(addr)
38            gdb.write('shadow addr: 0x%x\n' % shadow_addr)
39        else:
40            help()
41    def kasan_mem_to_shadow(self, addr):
42        return (addr >> self.p_ops.KASAN_SHADOW_SCALE_SHIFT) + self.p_ops.KASAN_SHADOW_OFFSET
43
44KasanMemToShadow()
45