import re
import textwrap
import unittest
from test import support
from test.support import import_helper, requires_subprocess
from test.support.script_helper import assert_python_failure, assert_python_ok
# Skip this test if the _testcapi and _testinternalcapi extensions are not
# available.
_testcapi = import_helper.import_module('_testcapi')
_testinternalcapi = import_helper.import_module('_testinternalcapi')
@requires_subprocess()
class PyMemDebugTests(unittest.TestCase):
PYTHONMALLOC = 'debug'
# '0x04c06e0' or '04C06E0'
PTR_REGEX = r'(?:0x)?[0-9a-fA-F]+'
def check(self, code):
with support.SuppressCrashReport():
out = assert_python_failure(
'-c', code,
PYTHONMALLOC=self.PYTHONMALLOC,
# FreeBSD: instruct jemalloc to not fill freed() memory
# with junk byte 0x5a, see JEMALLOC(3)
MALLOC_CONF="junk:false",
)
stderr = out.err
return stderr.decode('ascii', 'replace')
def test_buffer_overflow(self):
out = self.check('import _testcapi; _testcapi.pymem_buffer_overflow()')
regex = (r"Debug memory block at address p={ptr}: API 'm'\n"
r" 16 bytes originally requested\n"
r" The [0-9] pad bytes at p-[0-9] are FORBIDDENBYTE, as expected.\n"
r" The [0-9] pad bytes at tail={ptr} are not all FORBIDDENBYTE \(0x[0-9a-f]{{2}}\):\n"
r" at tail\+0: 0x78 \*\*\* OUCH\n"
r" at tail\+1: 0xfd\n"
r" at tail\+2: 0xfd\n"
r" .*\n"
r"( The block was made by call #[0-9]+ to debug malloc/realloc.\n)?"
r" Data at p: cd cd cd .*\n"
r"\n"
r"Enable tracemalloc to get the memory block allocation traceback\n"
r"\n"
r"Fatal Python error: _PyMem_DebugRawFree: bad trailing pad byte")
regex = regex.format(ptr=self.PTR_REGEX)
regex = re.compile(regex, flags=re.DOTALL)
self.assertRegex(out, regex)
def test_api_misuse(self):
out = self.check('import _testcapi; _testcapi.pymem_api_misuse()')
regex = (r"Debug memory block at address p={ptr}: API 'm'\n"
r" 16 bytes originally requested\n"
r" The [0-9] pad bytes at p-[0-9] are FORBIDDENBYTE, as expected.\n"
r" The [0-9] pad bytes at tail={ptr} are FORBIDDENBYTE, as expected.\n"
r"( The block was made by call #[0-9]+ to debug malloc/realloc.\n)?"
r" Data at p: cd cd cd .*\n"
r"\n"
r"Enable tracemalloc to get the memory block allocation traceback\n"
r"\n"
r"Fatal Python error: _PyMem_DebugRawFree: bad ID: Allocated using API 'm', verified using API 'r'\n")
regex = regex.format(ptr=self.PTR_REGEX)
self.assertRegex(out, regex)
def check_malloc_without_gil(self, code):
out = self.check(code)
expected = ('Fatal Python error: _PyMem_DebugMalloc: '
'Python memory allocator called without holding the GIL')
self.assertIn(expected, out)
def test_pymem_malloc_without_gil(self):
# Debug hooks must raise an error if PyMem_Malloc() is called
# without holding the GIL
code = 'import _testcapi; _testcapi.pymem_malloc_without_gil()'
self.check_malloc_without_gil(code)
def test_pyobject_malloc_without_gil(self):
# Debug hooks must raise an error if PyObject_Malloc() is called
# without holding the GIL
code = 'import _testcapi; _testcapi.pyobject_malloc_without_gil()'
self.check_malloc_without_gil(code)
def check_pyobject_is_freed(self, func_name):
code = textwrap.dedent(f'''
import gc, os, sys, _testinternalcapi
# Disable the GC to avoid crash on GC collection
gc.disable()
_testinternalcapi.{func_name}()
# Exit immediately to avoid a crash while deallocating
# the invalid object
os._exit(0)
''')
assert_python_ok(
'-c', code,
PYTHONMALLOC=self.PYTHONMALLOC,
MALLOC_CONF="junk:false",
)
def test_pyobject_null_is_freed(self):
self.check_pyobject_is_freed('check_pyobject_null_is_freed')
def test_pyobject_uninitialized_is_freed(self):
self.check_pyobject_is_freed('check_pyobject_uninitialized_is_freed')
def test_pyobject_forbidden_bytes_is_freed(self):
self.check_pyobject_is_freed('check_pyobject_forbidden_bytes_is_freed')
def test_pyobject_freed_is_freed(self):
self.check_pyobject_is_freed('check_pyobject_freed_is_freed')
# Python built with Py_TRACE_REFS fail with a fatal error in
# _PyRefchain_Trace() on memory allocation error.
@unittest.skipIf(support.Py_TRACE_REFS, 'cannot test Py_TRACE_REFS build')
def test_set_nomemory(self):
code = """if 1:
import _testcapi
class C(): pass
# The first loop tests both functions and that remove_mem_hooks()
# can be called twice in a row. The second loop checks a call to
# set_nomemory() after a call to remove_mem_hooks(). The third
# loop checks the start and stop arguments of set_nomemory().
for outer_cnt in range(1, 4):
start = 10 * outer_cnt
for j in range(100):
if j == 0:
if outer_cnt != 3:
_testcapi.set_nomemory(start)
else:
_testcapi.set_nomemory(start, start + 1)
try:
C()
except MemoryError as e:
if outer_cnt != 3:
_testcapi.remove_mem_hooks()
print('MemoryError', outer_cnt, j)
_testcapi.remove_mem_hooks()
break
"""
rc, out, err = assert_python_ok('-c', code)
lines = out.splitlines()
for i, line in enumerate(lines, 1):
self.assertIn(b'MemoryError', out)
*_, count = line.split(b' ')
count = int(count)
self.assertLessEqual(count, i*10)
self.assertGreaterEqual(count, i*10-4)
# free-threading requires mimalloc (not malloc)
@support.requires_gil_enabled()
class PyMemMallocDebugTests(PyMemDebugTests):
PYTHONMALLOC = 'malloc_debug'
@unittest.skipUnless(support.with_pymalloc(), 'need pymalloc')
class PyMemPymallocDebugTests(PyMemDebugTests):
PYTHONMALLOC = 'pymalloc_debug'
@unittest.skipUnless(support.with_mimalloc(), 'need mimaloc')
class PyMemMimallocDebugTests(PyMemDebugTests):
PYTHONMALLOC = 'mimalloc_debug'
@unittest.skipUnless(support.Py_DEBUG, 'need Py_DEBUG')
class PyMemDefaultTests(PyMemDebugTests):
# test default allocator of Python compiled in debug mode
PYTHONMALLOC = ''
if __name__ == "__main__":
unittest.main()
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