traverseda
/
cpython
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

bpo-38400 Don't check for NULL linked list pointers in _PyObject_IsFreed (GH-16630) 

Some objects like Py_None are not initialized with conventional means
that prepare the circular linked list pointers, leaving them unlinked
from the rest of the objects. For those objects, NULL pointers does
not mean that they are freed, so we need to skip the check in those
cases.
(cherry picked from commit 36e33c360e)

Co-authored-by: Pablo Galindo <Pablogsal@gmail.com>
This commit is contained in:
Miss Islington (bot) 2020-01-19 15:43:37 -08:00 committed by GitHub
parent 23793edf0d
commit 4cdb75890a
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 4 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
Objects/object.c
View File

@ -454,9 +454,12 @@ _PyObject_IsFreed(PyObject *op)
/* ignore op->ob_ref: its value can have be modified
by Py_INCREF() and Py_DECREF(). */
#ifdef Py_TRACE_REFS
if (_PyMem_IsPtrFreed(op->_ob_next) || _PyMem_IsPtrFreed(op->_ob_prev)) {
if (op->_ob_next != NULL && _PyMem_IsPtrFreed(op->_ob_next)) {
return 1;
}
if (op->_ob_prev != NULL && _PyMem_IsPtrFreed(op->_ob_prev)) {
return 1;
}
#endif
return 0;
}