From: Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com> Date: Tue, 5 Jan 2021 15:46:58 +0000 (-0800) Subject: [3.9] bpo-40052: Fix alignment issue in PyVectorcall_Function() (GH-23999) (GH-24005) X-Git-Tag: v3.9.2rc1~62 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=6e72ab909de58e89b5a7cd6899587e203cf129a3;p=thirdparty%2FPython%2Fcpython.git [3.9] bpo-40052: Fix alignment issue in PyVectorcall_Function() (GH-23999) (GH-24005) ``` In file included from /usr/include/python3.8/Python.h:147: In file included from /usr/include/python3.8/abstract.h:837: /usr/include/python3.8/cpython/abstract.h:91:11: error: cast from 'char *' to 'vectorcallfunc *' (aka 'struct _object *(**)(struct _object *, struct _object *const *, unsigned long, struct _object *)') increases required alignment from 1 to 8 [-Werror,-Wcast-align] ptr = (vectorcallfunc*)(((char *)callable) + offset); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 1 error generated. ``` Co-authored-by: Petr Viktorin Co-Authored-By: Andreas Schneider Co-Authored-By: Antoine Pitrou (cherry picked from commit 056c08211b402b4dbc1530a9de9d00ad5309909f) --- diff --git a/Include/cpython/abstract.h b/Include/cpython/abstract.h index 7bc80833a746..0f1304d26af3 100644 --- a/Include/cpython/abstract.h +++ b/Include/cpython/abstract.h @@ -67,7 +67,7 @@ PyVectorcall_Function(PyObject *callable) { PyTypeObject *tp; Py_ssize_t offset; - vectorcallfunc *ptr; + vectorcallfunc ptr; assert(callable != NULL); tp = Py_TYPE(callable); @@ -77,8 +77,8 @@ PyVectorcall_Function(PyObject *callable) assert(PyCallable_Check(callable)); offset = tp->tp_vectorcall_offset; assert(offset > 0); - ptr = (vectorcallfunc *)(((char *)callable) + offset); - return *ptr; + memcpy(&ptr, (char *) callable + offset, sizeof(ptr)); + return ptr; } /* Call the callable object 'callable' with the "vectorcall" calling diff --git a/Misc/NEWS.d/next/C API/2020-03-24-09-27-10.bpo-40052.27P2KG.rst b/Misc/NEWS.d/next/C API/2020-03-24-09-27-10.bpo-40052.27P2KG.rst new file mode 100644 index 000000000000..538488e2fbac --- /dev/null +++ b/Misc/NEWS.d/next/C API/2020-03-24-09-27-10.bpo-40052.27P2KG.rst @@ -0,0 +1,2 @@ +Fix an alignment build warning/error in function ``PyVectorcall_Function()``. +Patch by Andreas Schneider, Antoine Pitrou and Petr Viktorin. diff --git a/Objects/call.c b/Objects/call.c index 61426c7e09e4..87dc0dbbdb50 100644 --- a/Objects/call.c +++ b/Objects/call.c @@ -205,6 +205,7 @@ PyObject * PyVectorcall_Call(PyObject *callable, PyObject *tuple, PyObject *kwargs) { PyThreadState *tstate = _PyThreadState_GET(); + vectorcallfunc func; /* get vectorcallfunc as in PyVectorcall_Function, but without * the Py_TPFLAGS_HAVE_VECTORCALL check */ @@ -215,7 +216,7 @@ PyVectorcall_Call(PyObject *callable, PyObject *tuple, PyObject *kwargs) Py_TYPE(callable)->tp_name); return NULL; } - vectorcallfunc func = *(vectorcallfunc *)(((char *)callable) + offset); + memcpy(&func, (char *) callable + offset, sizeof(func)); if (func == NULL) { _PyErr_Format(tstate, PyExc_TypeError, "'%.200s' object does not support vectorcall",