From 9a6b60af409d02468b935c569a4f49e88c399c4e Mon Sep 17 00:00:00 2001 From: Kumar Aditya Date: Thu, 24 Jul 2025 23:28:46 +0530 Subject: [PATCH] gh-136870: fix data races in instrumentation of bytecode (#136994) De-instrumenting code objects modifies the thread local bytecode for all threads as such, holding the critical section on the code object is not sufficient and leads to data races. Now, the de-instrumentation is now performed under a stop the world pause as such no thread races with executing the thread local bytecode while it is being de-instrumented. --- ...-07-24-17-30-58.gh-issue-136870.ncx82J.rst | 1 + Python/instrumentation.c | 20 +++++++++++-------- 2 files changed, 13 insertions(+), 8 deletions(-) create mode 100644 Misc/NEWS.d/next/Core_and_Builtins/2025-07-24-17-30-58.gh-issue-136870.ncx82J.rst diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2025-07-24-17-30-58.gh-issue-136870.ncx82J.rst b/Misc/NEWS.d/next/Core_and_Builtins/2025-07-24-17-30-58.gh-issue-136870.ncx82J.rst new file mode 100644 index 000000000000..7552dc69169b --- /dev/null +++ b/Misc/NEWS.d/next/Core_and_Builtins/2025-07-24-17-30-58.gh-issue-136870.ncx82J.rst @@ -0,0 +1 @@ +Fix data races while de-instrumenting bytecode of code objects running concurrently in threads. diff --git a/Python/instrumentation.c b/Python/instrumentation.c index 44de480cd230..f9913cff402e 100644 --- a/Python/instrumentation.c +++ b/Python/instrumentation.c @@ -1190,9 +1190,10 @@ call_instrumentation_vector( break; } else { - LOCK_CODE(code); + PyInterpreterState *interp = tstate->interp; + _PyEval_StopTheWorld(interp); remove_tools(code, offset, event, 1 << tool); - UNLOCK_CODE(); + _PyEval_StartTheWorld(interp); } } } @@ -1381,9 +1382,10 @@ _Py_call_instrumentation_line(PyThreadState *tstate, _PyInterpreterFrame* frame, } else { /* DISABLE */ - LOCK_CODE(code); + PyInterpreterState *interp = tstate->interp; + _PyEval_StopTheWorld(interp); remove_line_tools(code, i, 1 << tool); - UNLOCK_CODE(); + _PyEval_StartTheWorld(interp); } } while (tools); Py_DECREF(line_obj); @@ -1438,9 +1440,10 @@ _Py_call_instrumentation_instruction(PyThreadState *tstate, _PyInterpreterFrame* } else { /* DISABLE */ - LOCK_CODE(code); + PyInterpreterState *interp = tstate->interp; + _PyEval_StopTheWorld(interp); remove_per_instruction_tools(code, offset, 1 << tool); - UNLOCK_CODE(); + _PyEval_StartTheWorld(interp); } } Py_DECREF(offset_obj); @@ -2995,9 +2998,10 @@ branch_handler_vectorcall( // Orphaned NOT_TAKEN -- Jump removed by the compiler return res; } - LOCK_CODE(code); + PyInterpreterState *interp = _PyInterpreterState_GET(); + _PyEval_StopTheWorld(interp); remove_tools(code, offset, other_event, 1 << self->tool_id); - UNLOCK_CODE(); + _PyEval_StartTheWorld(interp); } return res; } -- 2.47.3