When called on a closed object, readinto() segfaults on account
of a write to a freed buffer:
==220553== Process terminating with default action of signal 11 (SIGSEGV): dumping core
==220553== Access not within mapped region at address 0x2A
==220553== at 0x48408A0: memmove (vg_replace_strmem.c:1272)
==220553== by 0x58DB0C: _buffered_readinto_generic (bufferedio.c:972)
==220553== by 0x58DCBA: _io__Buffered_readinto_impl (bufferedio.c:1053)
==220553== by 0x58DCBA: _io__Buffered_readinto (bufferedio.c.h:253)
Reproducer:
reader = open ("/dev/zero", "rb")
_void = reader.read (42)
reader.close ()
reader.readinto (bytearray (42)) ### BANG!
The problem exists since 2012 when commit dc469454ec added code
to free the read buffer on close().
Signed-off-by: Philipp Gesang <philipp.gesang@intra2net.com>
Currently, during runtime destruction, `_PyImport_Cleanup` is clearing the interpreter state before clearing out the modules themselves. This leads to a segfault on modules that rely on the module state to clear themselves up.
For example, let's take the small snippet added in the issue by @DinoV :
```
import _struct
class C:
def __init__(self):
self.pack = _struct.pack
def __del__(self):
self.pack('I', -42)
_struct.x = C()
```
The module `_struct` uses the module state to run `pack`. Therefore, the module state has to be alive until after the module has been cleared out to successfully run `C.__del__`. This happens at line 606, when `_PyImport_Cleanup` calls `_PyModule_Clear`. In fact, the loop that calls `_PyModule_Clear` has in its comments:
> Now, if there are any modules left alive, clear their globals to minimize potential leaks. All C extension modules actually end up here, since they are kept alive in the interpreter state.
That means that we can't clear the module state (which is used by C Extensions) before we run that loop.
Moving `_PyInterpreterState_ClearModules` until after it, fixes the segfault in the code snippet.
Finally, this updates a test in `io` to correctly assert the error that it now throws (since it now finds the io module state). The test that uses this is: `test_create_at_shutdown_without_encoding`. Given this test is now working is a proof that the module state now stays alive even when `__del__` is called at module destruction time. Thus, I didn't add a new tests for this.
https://bugs.python.org/issue38076
Adds an additional assertion check based on a race condition for `test__xxsubinterpreters.DestroyTests.test_still_running` discovered in the bpo issue.
https://bugs.python.org/issue37224
Previously, a calltip might be left after SyntaxError, KeyboardInterrupt, or Shell Restart.
Co-authored-by: Terry Jan Reedy <tjreedy@udel.edu>
Co-authored-by: Tal Einat <taleinat+github@gmail.com>
* use the `: pass` and `: yield` patterns for code that isn't expected to ever be executed.
* The _Call items passed to _AnyComparer are only ever of length two, so assert instead of if/else
* fix typo
* Fix bug, where stop-without-start patching dict blows up with `TypeError: 'NoneType' object is not iterable`, highlighted by lack of coverage of an except branch.
* The fix for bpo-37972 means _Call.count and _Call.index are no longer needed.
* add coverage for calling next() on a mock_open with readline.return_value set.
* __aiter__ is defined on the Mock so the one on _AsyncIterator is never called.
Replace check for whether something is a method in the mock module. The
previous version fails on PyPy, because there no method wrappers exist
(everything looks like a regular Python-defined function). Thus the
isinstance(getattr(result, '__get__', None), MethodWrapperTypes) check
returns True for any descriptor, not just methods.
This condition could also return erroneously True in CPython for
C-defined descriptors.
Instead to decide whether something is a method, just check directly
whether it's a function defined on the class. This passes all tests on
CPython and fixes the bug on PyPy.
Improve multi-threaded performance by dropping the GIL in the fast path
of bytes.join. To avoid increasing overhead for small joins, it is only
done if the output size exceeds a threshold.
In bpo-36264 os.path.expanduser was changed to ignore HOME on Windows.
Path.expanduser/home still honored HOME despite being documented as behaving the same
as os.path.expanduser. This makes them also ignore HOME so that both implementations
behave the same way again.
Expose dialog buttons to test code and complete their test coverage.
Complete test coverage for highlights and keys tabs.
Co-authored-by: Terry Jan Reedy <tjreedy@udel.edu>
- The gc.collect is needed for other implementations, such as pypy
- Using context managers over multiple lines will only catch the warning from the first line in the context!
- remove a skip for a test that no longer fails on pypy
* Add DICT_UPDATE and DICT_MERGE bytecodes. Use them for ** unpacking.
* Remove BUILD_MAP_UNPACK and BUILD_MAP_UNPACK_WITH_CALL, as they are now unused.
* Update magic number for ** unpacking opcodes.
* Update dis.rst to incorporate new bytecodes.
* Add blurb entry.
The os.putenv() and os.unsetenv() functions are now always available.
On non-Windows platforms, Python now requires setenv() and unsetenv()
functions to build.
Remove putenv_dict from posixmodule.c: it's not longer needed.
Some portions of the pickle documentation hadn't been updated for the pickle protocol changes in Python 3.8 (new protocol 5, default protocol 4). This PR fixes those docs.
https://bugs.python.org/issue39426
As the function was not registering in the active patches, the mocks
started by `mock.patch.dict` were not being stopped when
`mock.patch.stopall` was being called.
* bpo-39421: Fix posible crash in heapq with custom comparison operators
* fixup! bpo-39421: Fix posible crash in heapq with custom comparison operators
* fixup! fixup! bpo-39421: Fix posible crash in heapq with custom comparison operators
* Add three new bytecodes: LIST_TO_TUPLE, LIST_EXTEND, SET_UPDATE. Use them to implement star unpacking expressions.
* Remove four bytecodes BUILD_LIST_UNPACK, BUILD_TUPLE_UNPACK, BUILD_SET_UNPACK and BUILD_TUPLE_UNPACK_WITH_CALL opcodes as they are now unused.
* Update magic number and dis.rst for new bytecodes.
Philipp Gesang
Stefan Behnel
Eddie Elizondo
Stefan Pochmann
Victor Stinner
Steve Cirelli
Pierre Glaser
Kyle Stanley
Andrew Svetlov
Zackery Spytz
damani42
Shantanu
Chris Withers
Carl Friedrich Bolz-Tereick
Bruce Merry
Rémi Lapeyre
Adam Meily
Christoph Reiter
Brian Quinlan
Cheryl Sabella
Dong-hee Na
Toshio Kuratomi
Mark Shannon
Karthikeyan Singaravelan
加和
Vegard Stikbakke
Łukasz Langa
Paulo Henrique Silva
Matthew Kokotovich
Serhiy Storchaka
mbarkhau
Mark Dickinson
Mario Corchero
Emmanuel Arias
Pablo Galindo