gh-143604: Hold strong reference to executor during JIT tracing

[Zheaoli]

• Issue: JIT: Use-after-free in stop_tracing_and_jit #143604

[Fidget-Spinner]

Full disclaimer: I wrote the test here and verified it crashes on ASAN on main branch.

[Zheaoli]

BTW, for the record, when I run ./python -m unittest -v test.test_capi.test_opt.TestExecutorInvalidation.test_prev_executor_freed_while_tracing. A new ASAN error has been raised

==3795402==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 2040 byte(s) in 1 object(s) allocated from:
    #0 0x7fe57ad20cb5 in malloc /usr/src/debug/gcc/gcc/libsanitizer/asan/asan_malloc_linux.cpp:67
    #1 0x5647b297e7c9 in _PyMem_RawMalloc Objects/obmalloc.c:64
    #2 0x5647b297db5f in _PyMem_DebugRawAlloc Objects/obmalloc.c:2926
    #3 0x5647b297dbc8 in _PyMem_DebugRawMalloc Objects/obmalloc.c:2959
    #4 0x5647b297f4a6 in _PyMem_DebugMalloc Objects/obmalloc.c:3124
    #5 0x5647b29a84bf in PyObject_Malloc Objects/obmalloc.c:1532
    #6 0x5647b2c7ece2 in _PyObject_MallocWithType Include/internal/pycore_object_alloc.h:46
    #7 0x5647b2c7ece2 in gc_alloc Python/gc.c:2352
    #8 0x5647b2c7ef4b in _PyObject_GC_NewVar Python/gc.c:2394
    #9 0x5647b2ce92b2 in allocate_executor Python/optimizer.c:1261
    #10 0x5647b2cf07ad in make_executor_from_uops Python/optimizer.c:1348
    #11 0x5647b2cf143d in uop_optimize Python/optimizer.c:1528
    #12 0x5647b2cf266c in _PyOptimizer_Optimize Python/optimizer.c:164
    #13 0x5647b2b34772 in stop_tracing_and_jit Python/ceval.c:1461
    #14 0x5647b2b7d2aa in _PyEval_EvalFrameDefault Python/generated_cases.c.h:11823
    #15 0x5647b2b80d59 in _PyEval_EvalFrame Include/internal/pycore_ceval.h:118
    #16 0x5647b2b810c2 in _PyEval_Vector Python/ceval.c:2541
    #17 0x5647b28b0877 in _PyFunction_Vectorcall Objects/call.c:413
    #18 0x5647b28b6cbf in _PyObject_VectorcallTstate Include/internal/pycore_call.h:136
    #19 0x5647b28b6fb1 in method_vectorcall Objects/classobject.c:95
    #20 0x5647b28b3f42 in _PyVectorcall_Call Objects/call.c:273
    #21 0x5647b28b441e in _PyObject_Call Objects/call.c:348
    #22 0x5647b28b4465 in PyObject_Call Objects/call.c:373
    #23 0x5647b2b4db07 in _PyEval_EvalFrameDefault Python/generated_cases.c.h:2876
    #24 0x5647b2b80d59 in _PyEval_EvalFrame Include/internal/pycore_ceval.h:118
    #25 0x5647b2b810c2 in _PyEval_Vector Python/ceval.c:2541
    #26 0x5647b28b0877 in _PyFunction_Vectorcall Objects/call.c:413
    #27 0x5647b28b37a4 in _PyObject_VectorcallDictTstate Objects/call.c:135
    #28 0x5647b28b3bb1 in _PyObject_Call_Prepend Objects/call.c:504
    #29 0x5647b29f04b2 in call_method Objects/typeobject.c:3088
    #30 0x5647b29f0684 in slot_tp_call Objects/typeobject.c:10681

I'm trying to figure it out why

[Fidget-Spinner]

I'm trying to figure it out why

Oops, I was testing this locally and also saw the ASAN leak so I fixed it. There's no more leak now.

[Zheaoli]

Oops, I was testing this locally and also saw the ASAN leak so I fixed it. There's no more leak now.

LOL, Thanks for the new commit. Actually I have never think about this part yet. Thanks for the leason #TIL