https://github.com/python/cpython/commit/313544eb0381d868b4f8b351a0ca808c313af698 commit: 313544eb0381d868b4f8b351a0ca808c313af698 branch: 3.11 author: Miss Islington (bot) <31488909+miss-isling...@users.noreply.github.com> committer: pablogsal <pablog...@gmail.com> date: 2025-06-16T14:51:04+02:00 summary:
[3.11] gh-127563: use `dk_log2_index_bytes=3` in empty dicts (GH-127568) (GH-127813) (#135463) [3.12] gh-127563: use `dk_log2_index_bytes=3` in empty dicts (GH-127568) (GH-127813) This fixes a UBSan failure (unaligned zero-size memcpy) in `dictobject.c`. (cherry picked from commit 9af96f440618304e7cc609c246e1f8c8b2d7a119) (cherry picked from commit 320a1dcd97110598a4fe6ae1c0018cd3decc408f) Co-authored-by: Bénédikt Tran <10796600+picn...@users.noreply.github.com> files: M Objects/dictobject.c diff --git a/Objects/dictobject.c b/Objects/dictobject.c index 69a4a865103c18..0e9c6d24e48338 100644 --- a/Objects/dictobject.c +++ b/Objects/dictobject.c @@ -449,11 +449,14 @@ estimate_log2_keysize(Py_ssize_t n) /* This immutable, empty PyDictKeysObject is used for PyDict_Clear() * (which cannot fail and thus can do no allocation). + * + * See https://github.com/python/cpython/pull/127568#discussion_r1868070614 + * for the rationale of using dk_log2_index_bytes=3 instead of 0. */ static PyDictKeysObject empty_keys_struct = { 1, /* dk_refcnt */ 0, /* dk_log2_size */ - 0, /* dk_log2_index_bytes */ + 3, /* dk_log2_index_bytes */ DICT_KEYS_UNICODE, /* dk_kind */ 1, /* dk_version */ 0, /* dk_usable (immutable) */ _______________________________________________ Python-checkins mailing list -- python-checkins@python.org To unsubscribe send an email to python-checkins-le...@python.org https://mail.python.org/mailman3//lists/python-checkins.python.org Member address: arch...@mail-archive.com
