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[3.12] gh-104690: thread_run() checks for tstate dangling pointer (#109056) (#109133)

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gh-104690: thread_run() checks for tstate dangling pointer (#109056)

thread_run() of _threadmodule.c now calls
_PyThreadState_CheckConsistency() to check if tstate is a dangling
pointer when Python is built in debug mode.

Rename ceval_gil.c is_tstate_valid() to
_PyThreadState_CheckConsistency() to reuse it in _threadmodule.c.

(cherry picked from commit f63d37877a)
This commit is contained in:
Victor Stinner 2023-10-02 16:55:06 +02:00 • committed by GitHub
parent 9207c870be
commit 30748d36b3
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4 changed files with 35 additions and 20 deletions
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26
Python/ceval_gil.c
View file

@ -162,16 +162,6 @@ UNSIGNAL_ASYNC_EXC(PyInterpreterState *interp)
COMPUTE_EVAL_BREAKER(interp, ceval, ceval2);
}
#ifndef NDEBUG
/* Ensure that tstate is valid */
static int
is_tstate_valid(PyThreadState *tstate)
{
assert(!_PyMem_IsPtrFreed(tstate));
assert(!_PyMem_IsPtrFreed(tstate->interp));
return 1;
}
#endif
/*
* Implementation of the Global Interpreter Lock (GIL).
@ -324,7 +314,7 @@ drop_gil(struct _ceval_state *ceval, PyThreadState *tstate)
/* Not switched yet => wait */
if (((PyThreadState*)_Py_atomic_load_relaxed(&gil->last_holder)) == tstate)
{
assert(is_tstate_valid(tstate));
assert(_PyThreadState_CheckConsistency(tstate));
RESET_GIL_DROP_REQUEST(tstate->interp);
/* NOTE: if COND_WAIT does not atomically start waiting when
releasing the mutex, another thread can run through, take
@ -385,7 +375,7 @@ take_gil(PyThreadState *tstate)
PyThread_exit_thread();
}
assert(is_tstate_valid(tstate));
assert(_PyThreadState_CheckConsistency(tstate));
PyInterpreterState *interp = tstate->interp;
struct _ceval_state *ceval = &interp->ceval;
struct _gil_runtime_state *gil = ceval->gil;
@ -426,7 +416,7 @@ take_gil(PyThreadState *tstate)
}
PyThread_exit_thread();
}
assert(is_tstate_valid(tstate));
assert(_PyThreadState_CheckConsistency(tstate));
SET_GIL_DROP_REQUEST(interp);
drop_requested = 1;
@ -465,7 +455,7 @@ _ready:
drop_gil(ceval, tstate);
PyThread_exit_thread();
}
assert(is_tstate_valid(tstate));
assert(_PyThreadState_CheckConsistency(tstate));
if (_Py_atomic_load_relaxed(&ceval->gil_drop_request)) {
RESET_GIL_DROP_REQUEST(interp);
@ -673,7 +663,7 @@ PyEval_AcquireThread(PyThreadState *tstate)
void
PyEval_ReleaseThread(PyThreadState *tstate)
{
assert(is_tstate_valid(tstate));
assert(_PyThreadState_CheckConsistency(tstate));
PyThreadState *new_tstate = _PyThreadState_SwapNoGIL(NULL);
if (new_tstate != tstate) {
@ -871,7 +861,7 @@ Py_AddPendingCall(int (*func)(void *), void *arg)
static int
handle_signals(PyThreadState *tstate)
{
assert(is_tstate_valid(tstate));
assert(_PyThreadState_CheckConsistency(tstate));
if (!_Py_ThreadCanHandleSignals(tstate->interp)) {
return 0;
}
@ -977,7 +967,7 @@ void
_Py_FinishPendingCalls(PyThreadState *tstate)
{
assert(PyGILState_Check());
assert(is_tstate_valid(tstate));
assert(_PyThreadState_CheckConsistency(tstate));
if (make_pending_calls(tstate->interp) < 0) {
PyObject *exc = _PyErr_GetRaisedException(tstate);
@ -1018,7 +1008,7 @@ Py_MakePendingCalls(void)
assert(PyGILState_Check());
PyThreadState *tstate = _PyThreadState_GET();
assert(is_tstate_valid(tstate));
assert(_PyThreadState_CheckConsistency(tstate));
/* Only execute pending calls on the main thread. */
if (!_Py_IsMainThread() || !_Py_IsMainInterpreter(tstate->interp)) {

18
Python/pystate.c
View file

@ -2848,6 +2848,24 @@ _PyThreadState_PopFrame(PyThreadState *tstate, _PyInterpreterFrame * frame)
}
#ifndef NDEBUG
// Check that a Python thread state valid. In practice, this function is used
// on a Python debug build to check if 'tstate' is a dangling pointer, if the
// PyThreadState memory has been freed.
//
// Usage:
//
// assert(_PyThreadState_CheckConsistency(tstate));
int
_PyThreadState_CheckConsistency(PyThreadState *tstate)
{
assert(!_PyMem_IsPtrFreed(tstate));
assert(!_PyMem_IsPtrFreed(tstate->interp));
return 1;
}
#endif
#ifdef __cplusplus
}
#endif