1# Copyright (C) 2021-2023 Free Software Foundation, Inc. 2 3# This program is free software; you can redistribute it and/or modify 4# it under the terms of the GNU General Public License as published by 5# the Free Software Foundation; either version 3 of the License, or 6# (at your option) any later version. 7# 8# This program is distributed in the hope that it will be useful, 9# but WITHOUT ANY WARRANTY; without even the implied warranty of 10# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11# GNU General Public License for more details. 12# 13# You should have received a copy of the GNU General Public License 14# along with this program. If not, see <http://www.gnu.org/licenses/>. 15 16import gdb 17from gdb.unwinder import Unwinder 18 19# Set this to the stack level the backtrace should be corrupted at. 20# This will only work for frame 1, 3, or 5 in the test this unwinder 21# was written for. 22stop_at_level = None 23 24# Set this to the stack frame size of frames 1, 3, and 5. These 25# frames will all have the same stack frame size as they are the same 26# function called recursively. 27stack_adjust = None 28 29 30class FrameId(object): 31 def __init__(self, sp, pc): 32 self._sp = sp 33 self._pc = pc 34 35 @property 36 def sp(self): 37 return self._sp 38 39 @property 40 def pc(self): 41 return self._pc 42 43 44class TestUnwinder(Unwinder): 45 def __init__(self): 46 Unwinder.__init__(self, "stop at level") 47 48 def __call__(self, pending_frame): 49 global stop_at_level 50 global stack_adjust 51 52 if stop_at_level is None or pending_frame.level() != stop_at_level: 53 return None 54 55 if stack_adjust is None: 56 raise gdb.GdbError("invalid stack_adjust") 57 58 if not stop_at_level in [1, 3, 5]: 59 raise gdb.GdbError("invalid stop_at_level") 60 61 sp_desc = pending_frame.architecture().registers().find("sp") 62 sp = pending_frame.read_register(sp_desc) + stack_adjust 63 pc = (gdb.lookup_symbol("normal_func"))[0].value().address 64 unwinder = pending_frame.create_unwind_info(FrameId(sp, pc)) 65 66 for reg in pending_frame.architecture().registers("general"): 67 val = pending_frame.read_register(reg) 68 unwinder.add_saved_register(reg, val) 69 return unwinder 70 71 72gdb.unwinder.register_unwinder(None, TestUnwinder(), True) 73 74# When loaded, it is expected that the stack looks like: 75# 76# main -> normal_func -> inline_func -> normal_func -> inline_func -> normal_func -> inline_func 77# 78# Compute the stack frame size of normal_func, which has inline_func 79# inlined within it. 80f0 = gdb.newest_frame() 81f1 = f0.older() 82f2 = f1.older() 83f0_sp = f0.read_register("sp") 84f2_sp = f2.read_register("sp") 85stack_adjust = f2_sp - f0_sp 86