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| author | Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com> | 2025-06-16 14:51:04 +0200 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2025-06-16 14:51:04 +0200 |
| commit | 313544eb0381d868b4f8b351a0ca808c313af698 (patch) | |
| tree | 19a2cb806244becc9ae877bd6d2e5debcdcd813f /Objects/dictobject.c | |
| parent | c96ab19ae460911e40ffa502f1bf945ab6c53a2e (diff) | |
| download | cpython-3.11.tar.gz cpython-3.11.zip | |
[3.11] gh-127563: use `dk_log2_index_bytes=3` in empty dicts (GH-127568) (GH-127813) (#135463)3.11
[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+picnixz@users.noreply.github.com>
Diffstat (limited to 'Objects/dictobject.c')
| -rw-r--r-- | Objects/dictobject.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/Objects/dictobject.c b/Objects/dictobject.c index 69a4a865103..0e9c6d24e48 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) */ |