Files
binutils-gdb/gdb/testsuite/gdb.python/py-unwind.py
Andrew Burgess 1d506c26d9 Update copyright year range in header of all files managed by GDB
This commit is the result of the following actions:

  - Running gdb/copyright.py to update all of the copyright headers to
    include 2024,

  - Manually updating a few files the copyright.py script told me to
    update, these files had copyright headers embedded within the
    file,

  - Regenerating gdbsupport/Makefile.in to refresh it's copyright
    date,

  - Using grep to find other files that still mentioned 2023.  If
    these files were updated last year from 2022 to 2023 then I've
    updated them this year to 2024.

I'm sure I've probably missed some dates.  Feel free to fix them up as
you spot them.
2024-01-12 15:49:57 +00:00

272 lines
9.4 KiB
Python

# Copyright (C) 2015-2024 Free Software Foundation, Inc.
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
import gdb
from gdb.unwinder import Unwinder, FrameId
# These are set to test whether invalid register names cause an error.
add_saved_register_errors = {}
read_register_error = False
class TestUnwinder(Unwinder):
AMD64_RBP = 6
AMD64_RSP = 7
AMD64_RIP = None
def __init__(self):
Unwinder.__init__(self, "test unwinder")
self.char_ptr_t = gdb.lookup_type("unsigned char").pointer()
self.char_ptr_ptr_t = self.char_ptr_t.pointer()
self._last_arch = None
# Update the register descriptor AMD64_RIP based on ARCH.
def _update_register_descriptors(self, arch):
if self._last_arch != arch:
TestUnwinder.AMD64_RIP = arch.registers().find("rip")
self._last_arch = arch
def _read_word(self, address):
return address.cast(self.char_ptr_ptr_t).dereference()
def __call__(self, pending_frame):
"""Test unwinder written in Python.
This unwinder can unwind the frames that have been deliberately
corrupted in a specific way (functions in the accompanying
py-unwind.c file do that.)
This code is only on AMD64.
On AMD64 $RBP points to the innermost frame (unless the code
was compiled with -fomit-frame-pointer), which contains the
address of the previous frame at offset 0. The functions
deliberately corrupt their frames as follows:
Before After
Corruption: Corruption:
+--------------+ +--------------+
RBP-8 | | | Previous RBP |
+--------------+ +--------------+
RBP + Previous RBP | | RBP |
+--------------+ +--------------+
RBP+8 | Return RIP | | Return RIP |
+--------------+ +--------------+
Old SP | | | |
This unwinder recognizes the corrupt frames by checking that
*RBP == RBP, and restores previous RBP from the word above it.
"""
# Check that we can access the architecture of the pending
# frame, and that this is the same architecture as for the
# currently selected inferior.
inf_arch = gdb.selected_inferior().architecture()
frame_arch = pending_frame.architecture()
if inf_arch != frame_arch:
raise gdb.GdbError("architecture mismatch")
self._update_register_descriptors(frame_arch)
try:
# NOTE: the registers in Unwinder API can be referenced
# either by name or by number. The code below uses both
# to achieve more coverage.
bp = pending_frame.read_register("rbp").cast(self.char_ptr_t)
if self._read_word(bp) != bp:
return None
# Found the frame that the test program has corrupted for us.
# The correct BP for the outer frame has been saved one word
# above, previous IP and SP are at the expected places.
previous_bp = self._read_word(bp - 8)
previous_ip = self._read_word(bp + 8)
previous_sp = bp + 16
try:
pending_frame.read_register("nosuchregister")
except ValueError as ve:
global read_register_error
read_register_error = str(ve)
frame_id = FrameId(
pending_frame.read_register(register=TestUnwinder.AMD64_RSP),
pending_frame.read_register(TestUnwinder.AMD64_RIP),
)
unwind_info = pending_frame.create_unwind_info(frame_id)
unwind_info.add_saved_register(TestUnwinder.AMD64_RBP, previous_bp)
unwind_info.add_saved_register(value=previous_ip, register="rip")
unwind_info.add_saved_register(register="rsp", value=previous_sp)
global add_saved_register_errors
try:
unwind_info.add_saved_register("nosuchregister", previous_sp)
except ValueError as ve:
add_saved_register_errors["unknown_name"] = str(ve)
try:
unwind_info.add_saved_register(999, previous_sp)
except ValueError as ve:
add_saved_register_errors["unknown_number"] = str(ve)
try:
unwind_info.add_saved_register("rsp", 1234)
except TypeError as ve:
add_saved_register_errors["bad_value"] = str(ve)
return unwind_info
except (gdb.error, RuntimeError):
return None
global_test_unwinder = TestUnwinder()
gdb.unwinder.register_unwinder(None, global_test_unwinder, True)
# These are filled in by the simple_unwinder class.
captured_pending_frame = None
captured_pending_frame_repr = None
captured_unwind_info = None
captured_unwind_info_repr = None
class simple_unwinder(Unwinder):
def __init__(self, name, sp=0x123, pc=0x456):
super().__init__(name)
self._sp = sp
self._pc = pc
def __call__(self, pending_frame):
global captured_pending_frame
global captured_pending_frame_repr
global captured_unwind_info
global captured_unwind_info_repr
assert pending_frame.is_valid()
if captured_pending_frame is None:
captured_pending_frame = pending_frame
captured_pending_frame_repr = repr(pending_frame)
fid = FrameId(self._sp, self._pc)
uw = pending_frame.create_unwind_info(frame_id=fid)
uw.add_saved_register("rip", gdb.Value(0x123))
uw.add_saved_register("rbp", gdb.Value(0x456))
uw.add_saved_register("rsp", gdb.Value(0x789))
captured_unwind_info = uw
captured_unwind_info_repr = repr(uw)
return None
# Return a dictionary of information about FRAME.
def capture_frame_information(frame):
name = frame.name()
level = frame.level()
language = frame.language()
function = frame.function()
architecture = frame.architecture()
pc = frame.pc()
sal = frame.find_sal()
try:
block = frame.block()
assert isinstance(block, gdb.Block)
except RuntimeError as rte:
assert str(rte) == "Cannot locate block for frame."
block = "RuntimeError: " + str(rte)
return {
"name": name,
"level": level,
"language": language,
"function": function,
"architecture": architecture,
"pc": pc,
"sal": sal,
"block": block,
}
# List of information about each frame. The index into this list is
# the frame level. This is populated by
# capture_all_frame_information.
all_frame_information = []
# Fill in the global ALL_FRAME_INFORMATION list.
def capture_all_frame_information():
global all_frame_information
all_frame_information = []
gdb.newest_frame().select()
frame = gdb.selected_frame()
count = 0
while frame is not None:
frame.select()
info = capture_frame_information(frame)
level = info["level"]
info["matched"] = False
while len(all_frame_information) <= level:
all_frame_information.append(None)
assert all_frame_information[level] is None
all_frame_information[level] = info
if frame.name == "main" or count > 10:
break
count += 1
frame = frame.older()
# Assert that every entry in the global ALL_FRAME_INFORMATION list was
# matched by the validating_unwinder.
def check_all_frame_information_matched():
global all_frame_information
for entry in all_frame_information:
assert entry["matched"]
# An unwinder that doesn't match any frames. What it does do is
# lookup information from the PendingFrame object and compare it
# against information stored in the global ALL_FRAME_INFORMATION list.
class validating_unwinder(Unwinder):
def __init__(self):
super().__init__("validating_unwinder")
def __call__(self, pending_frame):
info = capture_frame_information(pending_frame)
level = info["level"]
global all_frame_information
old_info = all_frame_information[level]
assert old_info is not None
assert not old_info["matched"]
for key, value in info.items():
assert key in old_info, key + " not in old_info"
assert type(value) == type(old_info[key])
if isinstance(value, gdb.Block):
assert value.start == old_info[key].start
assert value.end == old_info[key].end
assert value.is_static == old_info[key].is_static
assert value.is_global == old_info[key].is_global
else:
assert str(value) == str(old_info[key])
old_info["matched"] = True
return None
print("Python script imported")