:Constant hash for _PyNone_Type

yonillasky · yonillasky · commit 961b41f5d3ce · 2022-12-10T10:54:03.000+02:00
diff --git a/Include/object.h b/Include/object.h
@@ -691,6 +691,8 @@ PyAPI_DATA(PyObject) _Py_NotImplementedStruct; /* Don't use this directly */
 /* Macro for returning Py_NotImplemented from a function */
 #define Py_RETURN_NOTIMPLEMENTED return Py_NewRef(Py_NotImplemented)
 
+extern Py_ssize_t _PyHASH_NONE;
+
 /* Rich comparison opcodes */
 #define Py_LT 0
 #define Py_LE 1
diff --git a/Objects/object.c b/Objects/object.c
@@ -1638,6 +1638,16 @@ none_bool(PyObject *v)
     return 0;
 }
 
+Py_ssize_t _PyHASH_NONE;
+
+static Py_hash_t none_hash(PyObject *v)
+{
+#ifdef Py_DEBUG
+    assert(_Py_HashSecret_Initialized);
+#endif
+    return _PyHASH_NONE;
+}
+
 static PyNumberMethods none_as_number = {
     0,                          /* nb_add */
     0,                          /* nb_subtract */
@@ -1689,7 +1699,7 @@ PyTypeObject _PyNone_Type = {
     &none_as_number,    /*tp_as_number*/
     0,                  /*tp_as_sequence*/
     0,                  /*tp_as_mapping*/
-    0,                  /*tp_hash */
+    (hashfunc)none_hash,/* tp_hash */
     0,                  /*tp_call */
     0,                  /*tp_str */
     0,                  /*tp_getattro */
diff --git a/Python/bootstrap_hash.c b/Python/bootstrap_hash.c
@@ -543,6 +543,11 @@ _PyOS_URandomNonblock(void *buffer, Py_ssize_t size)
     return pyurandom(buffer, size, 0, 1);
 }
 
+void
+_Py_InitNoneHash() {
+    const unsigned char data[] = {0xFC, 0xA8, 0x64, 0x20};
+    _PyHASH_NONE = _Py_HashBytes(data, sizeof(data));
+}
 
 PyStatus
 _Py_HashRandomization_Init(const PyConfig *config)
@@ -576,14 +581,15 @@ _Py_HashRandomization_Init(const PyConfig *config)
            pyurandom() is non-blocking mode (blocking=0): see the PEP 524. */
         res = pyurandom(secret, secret_size, 0, 0);
         if (res < 0) {
+            _Py_HashSecret_Initialized = 0;
             return _PyStatus_ERR("failed to get random numbers "
                                  "to initialize Python");
         }
     }
+    _Py_InitNoneHash();
     return _PyStatus_OK();
 }
 
-
 void
 _Py_HashRandomization_Fini(void)
 {

Original file line number	Diff line number	Diff line change
`@@ -543,6 +543,11 @@ _PyOS_URandomNonblock(void *buffer, Py_ssize_t size)`
`543`	`543`	`return pyurandom(buffer, size, 0, 1);`
`544`	`544`	`}`
`545`	`545`
	`546`	`+void`
	`547 D6B4`	`+_Py_InitNoneHash() {`
	`548`	`+ const unsigned char data[] = {0xFC, 0xA8, 0x64, 0x20};`
	`549`	`+ _PyHASH_NONE = _Py_HashBytes(data, sizeof(data));`
	`550`	`+}`
`546`	`551`
`547`	`552`	`PyStatus`
`548`	`553`	`_Py_HashRandomization_Init(const PyConfig *config)`
`@@ -576,14 +581,15 @@ _Py_HashRandomization_Init(const PyConfig *config)`
`576`	`581`	`pyurandom() is non-blocking mode (blocking=0): see the PEP 524. */`
`577`	`582`	`res = pyurandom(secret, secret_size, 0, 0);`
`578`	`583`	`if (res < 0) {`
	`584`	`+ _Py_HashSecret_Initialized = 0;`
`579`	`585`	`return _PyStatus_ERR("failed to get random numbers "`
`580`	`586`	`"to initialize Python");`
`581`	`587`	`}`
`582`	`588`	`}`
	`589`	`+ _Py_InitNoneHash();`
`583`	`590`	`return _PyStatus_OK();`
`584`	`591`	`}`
`585`	`592`
`586`		`-`
`587`	`593`	`void`
`588`	`594`	`_Py_HashRandomization_Fini(void)`
`589`	`595`	`{`