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Valgrind reports uninitialised values in _TAIL_CALL_* opcodes with tail-calling interpreter #160800
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Description
Bug report
Running test_gc under Valgrind on main with --suppressions=Misc/valgrind-python.supp reports multiple Conditional jump or move depends on uninitialised value(s) in _TAIL_CALL_* handlers.
Tracing via --track-origins=yes points to stack allocation in _PyEval_EvalFrameDefault (ceval.c:1269). Existing suppressions in Misc/valgrind-python.supp do not cover these occurrences.
Steps to reproduce
./configure --with-tail-call-interp --with-pydebug --with-valgrind
make -j$(nproc)
valgrind --track-origins=yes --suppressions=Misc/valgrind-python.supp -- ./python -m test test_gcActual behavior
==2951043== Conditional jump or move depends on uninitialised value(s)
==2951043== at 0x4276413: _TAIL_CALL_RETURN_VALUE (generated_cases.c.h:11514)
==2951043== by 0x4278B6F: _PyEval_EvalFrameDefault (ceval.c:1377)
==2951043== by 0x4278C0C: _PyEval_EvalFrame (pycore_ceval.h:122)
==2951043== by 0x4278DFB: _PyEval_Vector (ceval.c:2264)
==2951043== by 0x426D9EB: builtin___build_class__ (bltinmodule.c:207)
==2951043== by 0x41A3422: cfunction_vectorcall_FASTCALL_KEYWORDS (methodobject.c:464)
==2951043== by 0x4143239: _PyObject_VectorcallTstate (pycore_call.h:143)
==2951043== by 0x414330D: PyObject_Vectorcall (call.c:327)
==2951043== by 0x4275A1B: _Py_VectorCallInstrumentation_StackRefSteal (ceval.c:791)
==2951043== by 0x4282772: _TAIL_CALL_CALL (generated_cases.c.h:1906)
==2951043== by 0x4278B6F: _PyEval_EvalFrameDefault (ceval.c:1377)
==2951043== by 0x4278C0C: _PyEval_EvalFrame (pycore_ceval.h:122)
==2951043== Uninitialised value was created by a stack allocation
==2951043== at 0x4278903: _PyEval_EvalFrameDefault (ceval.c:1269)
==2951043== Conditional jump or move depends on uninitialised value(s)
==2951043== at 0x42740F7: _TAIL_CALL_YIELD_VALUE (generated_cases.c.h:13620)
==2951043== by 0x4278B6F: _PyEval_EvalFrameDefault (ceval.c:1377)
...
==2951043== Uninitialised value was created by a stack allocation
==2951043== at 0x4278903: _PyEval_EvalFrameDefault (ceval.c:1269)
Similar warnings also occur in:
_TAIL_CALL_RETURN_GENERATOR(generated_cases.c.h:11471)
Operating systems tested on
- Linux (Arch Linux, GCC 16, Valgrind 3.25.1)
### CPython versions tested on:
CPython main branch
### Operating systems tested on:
Linux
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