GH-139193: Fix dump_stack when PYTHON_LLTRACE=4

[sergey-miryanov]

There are two problems:

1. dump_stack/dump_item should ignore items that pushed on the stack with PyStackRef_Wrap
2. PyStackRef_IsError should test only Py_TAG_BITS of .bits not whole .bits value

Also, PyStackRef_IsValid should be fixed accordingly.

• Issue: JIT (interpreter): running hot code with PYTHON_LLTRACE=4 segfaults #139193

[sergey-miryanov]

PR ready to review, please take a look.

[Fidget-Spinner]

LGTM. Thanks!

[sergey-miryanov]

@Fidget-Spinner Thanks for review! I tried to fix PyStackRef_IsValid accordingly, because I oversight it yesterday.

[sergey-miryanov]

I revert it because it was not right.

[markshannon]

PyStackRef_IsError should return true only for PyStackRef_ERROR

[markshannon]

Any suggestions for a better name are welcome, as it is obviously not clear.

[sergey-miryanov]

@markshannon What do you think about adding new function PyStackRef_IsInvalid to check is INVALID bit is set or no? And fix PyStackRef_IsError to check as you said above?

[markshannon]

@markshannon What do you think about adding new function PyStackRef_IsInvalid to check is INVALID bit is set or no? And fix PyStackRef_IsError to check as you said above?

That sounds good. Leave PyStackRef_IsError untouched and add PyStackRef_IsMalformed.
It is tricky choosing a name that indicates that the stackef is broken, not that the ref is correct but thing it refers to is broken.
I think "malformed" conveys that a bit better than "invalid", but feel free to pick the name you think is clearest.

[sergey-miryanov]

@markshannon Please take a look. I have added PyStackRef_IsMalformed for default and no-gil builds. For Py_STACKREF_DEBUG we can add it after gh-139475 merged.

[markshannon]

Thanks for doing this

[sergey-miryanov]

Thanks everyone for reviews!

[bedevere-bot]

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

Hi! The buildbot x86 Debian Non-Debug with X 3.x (no tier) has failed when building commit a4709e5.

What do you need to do:

1. Don't panic.
2. Check the buildbot page in the devguide if you don't know what the buildbots are or how they work.
3. Go to the page of the buildbot that failed (https://buildbot.python.org/#/builders/1245/builds/6677) and take a look at the build logs.
4. Check if the failure is related to this commit (a4709e5) or if it is a false positive.
5. If the failure is related to this commit, please, reflect that on the issue and make a new Pull Request with a fix.

You can take a look at the buildbot page here:

https://buildbot.python.org/#/builders/1245/builds/6677

Summary of the results of the build (if available):

==

Click to see traceback logs

Traceback (most recent call last): File �[35m"/buildbot/buildarea/3.x.ware-debian-x86.nondebug/build/Lib/contextlib.py"�[0m, line �[35m85�[0m, in �[35minner�[0m return func(*args, **kwds) File �[35m"/buildbot/buildarea/3.x.ware-debian-x86.nondebug/build/Lib/test/_test_multiprocessing.py"�[0m, line �[35m596�[0m, in �[35mtest_interrupt�[0m exitcode =self._kill_process(multiprocessing.Process.interrupt) File �[35m"/buildbot/buildarea/3.x.ware-debian-x86.nondebug/build/Lib/contextlib.py"�[0m, line �[35m85�[0m, in �[35minner�[0m return func(*args, **kwds) File �[35m"/buildbot/buildarea/3.x.ware-debian-x86.nondebug/build/Lib/test/_test_multiprocessing.py"�[0m, line �[35m577�[0m, in �[35m_kill_process�[0m self.assertEqual(�[31mjoin�[0m�[1;31m()�[0m, None) �[31m~~~~�[0m�[1;31m^^�[0m File �[35m"/buildbot/buildarea/3.x.ware-debian-x86.nondebug/build/Lib/test/_test_multiprocessing.py"�[0m, line �[35m250�[0m, in �[35m__call__�[0m return �[31mself.func�[0m�[1;31m(*args, **kwds)�[0m �[31m~~~~~~~~~�[0m�[1;31m^^^^^^^^^^^^^^^�[0m File �[35m"/buildbot/buildarea/3.x.ware-debian-x86.nondebug/build/Lib/multiprocessing/process.py"�[0m, line �[35m156�[0m, in �[35mjoin�[0m res =self._popen.wait(timeout) File �[35m"/buildbot/buildarea/3.x.ware-debian-x86.nondebug/build/Lib/multiprocessing/popen_fork.py"�[0m, line �[35m44�[0m, in �[35mwait�[0m return �[31mself.poll�[0m�[1;31m(os.WNOHANGif timeout ==0.0else0)�[0m �[31m~~~~~~~~~�[0m�[1;31m^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^�[0m File �[35m"/buildbot/buildarea/3.x.ware-debian-x86.nondebug/build/Lib/multiprocessing/popen_fork.py"�[0m, line �[35m28�[0m, in �[35mpoll�[0m pid, sts = �[31mos.waitpid�[0m�[1;31m(self.pid, flag)�[0m �[31m~~~~~~~~~~�[0m�[1;31m^^^^^^^^^^^^^^^^�[0m File �[35m"/buildbot/buildarea/3.x.ware-debian-x86.nondebug/build/Lib/test/_test_multiprocessing.py"�[0m, line �[35m573�[0m, in �[35mhandler�[0m raiseRuntimeError('join took too long: %s'% p) �[1;35mRuntimeError�[0m: �[35mjoin took too long: <Process name='Process-1' pid=2952 parent=2950 started daemon>�[0m Traceback (most recent call last): File �[35m"/buildbot/buildarea/3.x.ware-debian-x86.nondebug/build/Lib/contextlib.py"�[0m, line �[35m85�[0m, in �[35minner�[0m return func(*args, **kwds) File �[35m"/buildbot/buildarea/3.x.ware-debian-x86.nondebug/build/Lib/test/_test_multiprocessing.py"�[0m, line �[35m596�[0m, in �[35mtest_interrupt�[0m exitcode =self._kill_process(multiprocessing.Process.interrupt) File �[35m"/buildbot/buildarea/3.x.ware-debian-x86.nondebug/build/Lib/contextlib.py"�[0m, line �[35m85�[0m, in �[35minner�[0m return func(*args, **kwds) File �[35m"/buildbot/buildarea/3.x.ware-debian-x86.nondebug/build/Lib/test/_test_multiprocessing.py"�[0m, line �[35m577�[0m, in �[35m_kill_process�[0m self.assertEqual(�[31mjoin�[0m�[1;31m()�[0m, None) �[31m~~~~�[0m�[1;31m^^�[0m File �[35m"/buildbot/buildarea/3.x.ware-debian-x86.nondebug/build/Lib/test/_test_multiprocessing.py"�[0m, line �[35m250�[0m, in �[35m__call__�[0m return �[31mself.func�[0m�[1;31m(*args, **kwds)�[0m �[31m~~~~~~~~~�[0m�[1;31m^^^^^^^^^^^^^^^�[0m File �[35m"/buildbot/buildarea/3.x.ware-debian-x86.nondebug/build/Lib/multiprocessing/process.py"�[0m, line �[35m156�[0m, in �[35mjoin�[0m res =self._popen.wait(timeout) File �[35m"/buildbot/buildarea/3.x.ware-debian-x86.nondebug/build/Lib/multiprocessing/popen_fork.py"�[0m, line �[35m44�[0m, in �[35mwait�[0m return �[31mself.poll�[0m�[1;31m(os.WNOHANGif timeout ==0.0else0)�[0m �[31m~~~~~~~~~�[0m�[1;31m^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^�[0m File �[35m"/buildbot/buildarea/3.x.ware-debian-x86.nondebug/build/Lib/multiprocessing/popen_fork.py"�[0m, line �[35m28�[0m, in �[35mpoll�[0m pid, sts = �[31mos.waitpid�[0m�[1;31m(self.pid, flag)�[0m �[31m~~~~~~~~~~�[0m�[1;31m^^^^^^^^^^^^^^^^�[0m File �[35m"/buildbot/buildarea/3.x.ware-debian-x86.nondebug/build/Lib/test/_test_multiprocessing.py"�[0m, line �[35m573�[0m, in �[35mhandler�[0m raiseRuntimeError('join took too long: %s'% p) �[1;35mRuntimeError�[0m: �[35mjoin took too long: <Process name='Process-159' pid=23294 parent=22521 started daemon>�[0m