At Python exit, sometimes a thread holding the GIL can wait forever
for a thread (usually a daemon thread) which requested to drop the
GIL, whereas the thread already exited. To fix the race condition,
the thread which requested the GIL drop now resets its request before
exiting.
take_gil() now calls RESET_GIL_DROP_REQUEST() before
PyThread_exit_thread() if it called SET_GIL_DROP_REQUEST to fix a
race condition with drop_gil().
Issue discovered and analyzed by Mingliang ZHAO.
Integer to and from text conversions via CPython's bignum `int` type is not safe against denial of service attacks due to malicious input. Very large input strings with hundred thousands of digits can consume several CPU seconds.
This PR comes fresh from a pile of work done in our private PSRT security response team repo.
Signed-off-by: Christian Heimes [Red Hat] <christian@python.org>
Tons-of-polishing-up-by: Gregory P. Smith [Google] <greg@krypto.org>
Reviews via the private PSRT repo via many others (see the NEWS entry in the PR).
<!-- gh-issue-number: gh-95778 -->
* Issue: gh-95778
<!-- /gh-issue-number -->
I wrote up [a one pager for the release managers](https://docs.google.com/document/d/1KjuF_aXlzPUxTK4BMgezGJ2Pn7uevfX7g0_mvgHlL7Y/edit#). Much of that text wound up in the Issue. Backports PRs already exist. See the issue for links.
⚠️⚠️ Note for reviewers, hackers and fellow systems/low-level/compiler engineers ⚠️⚠️
If you have a lot of experience with this kind of shenanigans and want to improve the **first** version, **please make a PR against my branch** or **reach out by email** or **suggest code changes directly on GitHub**.
If you have any **refinements or optimizations** please, wait until the first version is merged before starting hacking or proposing those so we can keep this PR productive.
* gh-93503: Add APIs to set profiling and tracing functions in all threads in the C-API
* Use a separate API
* Fix NEWS entry
* Add locks around the loop
* Document ignoring exceptions
* Use the new APIs in the sys module
* Update docs
- "comparison of integers of different signs" in typeobject.c
- only define static_builtin_index_is_set in DEBUG builds
- only define recreate_gil with ifdef HAVE_FORK
Automate WASM build with a new Python script. The script provides
several build profiles with configure flags for Emscripten flavors
and WASI. The script can detect and use Emscripten SDK and WASI SDK from
default locations or env vars.
``configure`` now detects Node arguments and creates HOSTRUNNER
arguments for Node 16. It also sets correct arguments for
``wasm64-emscripten``.
Co-authored-by: Brett Cannon <brett@python.org>
We only statically initialize for core code and builtin modules. Extension modules still create
the tuple at runtime. We'll solve that part of interpreter isolation separately.
This change includes generated code. The non-generated changes are in:
* Tools/clinic/clinic.py
* Python/getargs.c
* Include/cpython/modsupport.h
* Makefile.pre.in (re-generate global strings after running clinic)
* very minor tweaks to Modules/_codecsmodule.c and Python/Python-tokenize.c
All other changes are generated code (clinic, global strings).
gh-93243
This PR is required to reduce diffs of the following porting (no need to either maintain documentation and tests consistent with each porting step, or try to port everything and remove smtpd in a single PR).
Automerge-Triggered-By: GH:warsaw
When keyword argument name is an instance of a str subclass with
overloaded methods __eq__ and __hash__, the former code could not find
the name of an extraneous keyword argument to report an error, and
_PyArg_UnpackKeywords() returned success without setting the
corresponding cell in the linearized arguments array. But since the number
of expected initialized cells is determined as the total number of passed
arguments, this lead to reading NULL as a keyword parameter value, that
caused SystemError or crash or other undesired behavior.
- check for ``dup()`` libc function
- handle missing ``F_DUPFD`` in ``dup2()`` replacement function
- add workaround for WASI libc bug in MSG_TRUNC
- ESHUTDOWN is missing, use EPIPE instead
- POLLPRI is missing, define as 0 (no-op)
Static builtin types are finalized by calling _PyStaticType_Dealloc(). Before this change, we were skipping finalizing such a type if it still had subtypes (i.e. its tp_subclasses hadn't been cleared yet). The problem is that types hold several heap objects, which leak if we skip the type's finalization. This change addresses that.
For context, there's an old comment (from e9e3eab0b8) that says the following:
// If a type still has subtypes, it cannot be deallocated.
// A subtype can inherit attributes and methods of its parent type,
// and a type must no longer be used once it's deallocated.
However, it isn't clear that is actually still true. Clearing tp_dict should mean it isn't a problem.
Furthermore, the only subtypes that might still be around come from extension modules that didn't clean them up when unloaded (i.e. extensions that do not implement multi-phase initialization, AKA PEP 489). Those objects are already leaking, so this change doesn't change anything in that regard. Instead, this change means more objects gets cleaned up that before.
This is the first of several precursors to storing tp_subclasses (and tp_weaklist) on the interpreter state for static builtin types.
We do the following:
* add `_PyStaticType_InitBuiltin()`
* add `_Py_TPFLAGS_STATIC_BUILTIN`
* set it on all static builtin types in `_PyStaticType_InitBuiltin()`
* shuffle some code around to be able to use _PyStaticType_InitBuiltin()
* rename `_PyStructSequence_InitType()` to `_PyStructSequence_InitBuiltinWithFlags()`
* add `_PyStructSequence_InitBuiltin()`.
* gh-93883: elide traceback indicators when possible
Elide traceback column indicators when the entire line of the
frame is implicated. This reduces traceback length and draws
even more attention to the remaining (very relevant) indicators.
Example:
```
Traceback (most recent call last):
File "query.py", line 99, in <module>
bar()
File "query.py", line 66, in bar
foo()
File "query.py", line 37, in foo
magic_arithmetic('foo')
File "query.py", line 18, in magic_arithmetic
return add_counts(x) / 25
^^^^^^^^^^^^^
File "query.py", line 24, in add_counts
return 25 + query_user(user1) + query_user(user2)
^^^^^^^^^^^^^^^^^
File "query.py", line 32, in query_user
return 1 + query_count(db, response['a']['b']['c']['user'], retry=True)
~~~~~~~~~~~~~~~~~~^^^^^
TypeError: 'NoneType' object is not subscriptable
```
Rather than going out of our way to provide indicator coverage
in every traceback test suite, the indicator test suite should
be responible for sufficient coverage (e.g. by adding a basic
exception group test to ensure that margin strings are covered).
Inlining of code that corresponds to source code lines, can make it hard to distinguish later between code which is only reachable from except handlers, and that which is reachable in normal control flow. This caused problems with the debugger's jump feature.
This PR turns off the inlining optimisation for code which has line numbers. We still inline things like the implicit "return None".
Seems in the past the copy of builtins was not made in some scenarios,
and the error was silenced. Write it now to stderr, so we have a chance
to see it.
pthread _PyThread_cond_after() implementation now uses the _PyTime_t
type to handle properly overflow: clamp to the maximum value.
Remove MICROSECONDS_TO_TIMESPEC() function.
On Windows, PyOS_StdioReadline() now gets
PyConfig.legacy_windows_stdio from _PyOS_ReadlineTState, rather than
using the deprecated global Py_LegacyWindowsStdioFlag variable.
Fix also a compiler warning in Py_SetStandardStreamEncoding().
Move the follow functions and type from frameobject.h to pyframe.h,
so the standard <Python.h> provide frame getter functions:
* PyFrame_Check()
* PyFrame_GetBack()
* PyFrame_GetBuiltins()
* PyFrame_GetGenerator()
* PyFrame_GetGlobals()
* PyFrame_GetLasti()
* PyFrame_GetLocals()
* PyFrame_Type
Remove #include "frameobject.h" from many C files. It's no longer
needed.
Reformat the pthread implementation of PyThread_acquire_lock_timed()
using a mutex and a conditioinal variable.
* Add goto to avoid multiple indentation levels and exit quickly
* Use "while(1)" and make the control flow more obvious.
* PEP 7: Add braces around if blocks.
Deprecate global configuration variable like
Py_IgnoreEnvironmentFlag: the Py_InitializeFromConfig() API should be
instead.
Fix declaration of Py_GETENV(): use PyAPI_FUNC(), not PyAPI_DATA().
It combines PyImport_ImportModule() and PyObject_GetAttrString()
and saves 4-6 lines of code on every use.
Add also _PyImport_GetModuleAttr() which takes Python strings as arguments.
This was added for bpo-40514 (gh-84694) to test out a per-interpreter GIL. However, it has since proven unnecessary to keep the experiment in the repo. (It can be done as a branch in a fork like normal.) So here we are removing:
* the configure option
* the macro
* the code enabled by the macro
Fix __lltrace__ debug feature if the stdout encoding is not UTF-8.
If the stdout encoding is not UTF-8, the first call to
lltrace_resume_frame() indirectly sets lltrace to 0 when calling
unicode_check_encoding_errors() which calls
encodings.search_function().
The Py_DecodeLocale() and Py_EncodeLocale() now use
_PyRuntime.preconfig, rather than Py_UTF8Mode and
Py_LegacyWindowsFSEncodingFlag global configuration varibles, to
decide if the UTF-8 encoding is used or not.
As documented, these functions must not be called before Python is
preinitialized. The new PyConfig API should now be used, rather than
using deprecated functions like Py_SetPath() or PySys_SetArgv().
Also while there, clarify a few things about why we reduce the hash to 32 bits.
Co-authored-by: Eli Libman <eli@hyro.ai>
Co-authored-by: Yury Selivanov <yury@edgedb.com>
Co-authored-by: Łukasz Langa <lukasz@langa.pl>
Remove the token.h header file. There was never any public tokenizer
C API. The token.h header file was only designed to be used by Python
internals.
Move Include/token.h to Include/internal/pycore_token.h. Including
this header file now requires that the Py_BUILD_CORE macro is
defined. It no longer checks for the Py_LIMITED_API macro.
Rename functions:
* PyToken_OneChar() => _PyToken_OneChar()
* PyToken_TwoChars() => _PyToken_TwoChars()
* PyToken_ThreeChars() => _PyToken_ThreeChars()
Irit Katriel
serge-sans-paille
Victor Stinner
Brandt Bucher
adphrost
Nikita Sobolev
Kevin Modzelewski
Mark Shannon
Kumar Aditya
Itamar Ostricher
Steve Dower
Dennis Sweeney
Gregory P. Smith
Pablo Galindo Salgado
Christian Heimes
Matthias Görgens
Ken Jin
Erlend E. Aasland
Eric Snow
zhanpon
Oleg Iarygin
Serhiy Storchaka
John Belmonte
neonene
Ken Jin
Ken Jin
Éric
Éric
Yury Selivanov
David CARLIER
Crowthebird
Inada Naoki
zikcheng
Gregory P. Smith