Merge remote-tracking branch 'upstream/3.10' into 3.10

Doc/library/timeit.rst

@@ -282,6 +282,13 @@ It is possible to provide a setup statement that is executed only once at the be
    $ python -m timeit -s 'text = "sample string"; char = "g"'  'text.find(char)'
    1000000 loops, best of 5: 0.342 usec per loop
 
+In the output, there are three fields. The loop count, which tells you how many
+times the statement body was run per timing loop repetition. The repetition
+count ('best of 5') which tells you how many times the timing loop was
+repeated, and finally the time the statement body took on average within the
+best repetition of the timing loop. That is, the time the fastest repetition
+took divided by the loop count.
+
 ::
 
    >>> import timeit

Misc/NEWS.d/next/Core and Builtins/2022-01-13-17-58-56.bpo-46070.q8IGth.rst

@@ -0,0 +1,5 @@
+:c:func:`Py_EndInterpreter` now explicitly untracks all objects currently
+tracked by the GC. Previously, if an object was used later by another
+interpreter, calling :c:func:`PyObject_GC_UnTrack` on the object crashed if the
+previous or the next object of the :c:type:`PyGC_Head` structure became a
+dangling pointer. Patch by Victor Stinner.

Modules/_hashopenssl.c

@@ -883,7 +883,7 @@ py_evp_fromname(PyObject *module, const char *digestname, PyObject *data_obj,
         goto exit;
     }
 
-#if defined(EVP_MD_CTX_FLAG_NON_FIPS_ALLOW) &&  OPENSSL_VERSION_NUMBER >= 0x30000000L
+#if defined(EVP_MD_CTX_FLAG_NON_FIPS_ALLOW) && OPENSSL_VERSION_NUMBER < 0x30000000L
     // In OpenSSL 1.1.1 the non FIPS allowed flag is context specific while
     // in 3.0.0 it is a different EVP_MD provider.
     if (!usedforsecurity) {

Modules/_tracemalloc.c

@@ -1241,6 +1241,9 @@ tracemalloc_copy_domain(_Py_hashtable_t *domains,
     _Py_hashtable_t *traces = (_Py_hashtable_t *)value;
 
     _Py_hashtable_t *traces2 = tracemalloc_copy_traces(traces);
+    if (traces2 == NULL) {
+        return -1;
+    }
     if (_Py_hashtable_set(domains2, TO_PTR(domain), traces2) < 0) {
         _Py_hashtable_destroy(traces2);
         return -1;

Modules/gcmodule.c

@@ -2162,12 +2162,36 @@ _PyGC_DumpShutdownStats(PyInterpreterState *interp)
     }
 }
 
+
+static void
+gc_fini_untrack(PyGC_Head *list)
+{
+    PyGC_Head *gc;
+    for (gc = GC_NEXT(list); gc != list; gc = GC_NEXT(list)) {
+        PyObject *op = FROM_GC(gc);
+        _PyObject_GC_UNTRACK(op);
+    }
+}
+
+
 void
 _PyGC_Fini(PyInterpreterState *interp)
 {
     GCState *gcstate = &interp->gc;
     Py_CLEAR(gcstate->garbage);
     Py_CLEAR(gcstate->callbacks);
+
+    if (!_Py_IsMainInterpreter(interp)) {
+        // bpo-46070: Explicitly untrack all objects currently tracked by the
+        // GC. Otherwise, if an object is used later by another interpreter,
+        // calling PyObject_GC_UnTrack() on the object crashs if the previous
+        // or the next object of the PyGC_Head structure became a dangling
+        // pointer.
+        for (int i = 0; i < NUM_GENERATIONS; i++) {
+            PyGC_Head *gen = GEN_HEAD(gcstate, i);
+            gc_fini_untrack(gen);
+        }
+    }
 }
 
 /* for debugging */