Backport #9206: protect FL_MARK at rb_obj_clone()

• Status: Closed
• Assignee: usa (Usaku NAKAMURA)

[authorNari (Narihiro Nakamura)]

=begin
rb_obj_clone()の時にコピー用に作成したオブジェクトにマークビットが付く可能性があり、そのマークを誤って消してしまうバグを修正しました。
flagsのコピー時にオリジナルのFL_MARKを守るようにしています。

Ruby 2.0.0についてはビットマップマーキングを利用しているためこのパッチを適用する必要はないと思います。

diff --git a/object.c b/object.c
index 0a0b260..1ab28a3 100644
--- a/object.c
+++ b/object.c
@@ -285,7 +285,7 @@ rb_obj_clone(VALUE obj)
}
clone = rb_obj_alloc(rb_obj_class(obj));
RBASIC(clone)->klass = rb_singleton_class_clone(obj);

• RBASIC(clone)->flags = (RBASIC(obj)->flags | FL_TEST(clone, FL_TAINT) | FL_TEST(clone, FL_UNTRUSTED)) & ~(FL_FREEZE|FL_FINALIZE|FL_MARK);

• RBASIC(clone)->flags = (RBASIC(obj)->flags | FL_TEST(clone, FL_TAINT) | FL_TEST(clone, FL_UNTRUSTED)) & ~(FL_FREEZE|FL_FINALIZE|FL_MARK) | (RBASIC(clone)->flags&FL_MARK);
  init_copy(clone, obj);
  rb_funcall(clone, id_init_clone, 1, obj);
  RBASIC(clone)->flags |= RBASIC(obj)->flags & FL_FREEZE;
  =end

[authorNari (Narihiro Nakamura)]

• File fix_to_unprotected_FL_MARK.patch fix_to_unprotected_FL_MARK.patch added

肝心のパッチを付けるのを忘れてました…。

[usa (Usaku NAKAMURA)]

• Status changed from Open to Closed
• % Done changed from 0 to 100

This issue was solved with changeset r44337.
Narihiro, thank you for reporting this issue.
Your contribution to Ruby is greatly appreciated.
May Ruby be with you.

---

• object.c (rb_obj_clone): protect FL_MARK of a dest object. A lazy
  sweeper free up a dest object if a marker is invoked immediately
  following allocate a dest object in rb_obj_alloc().
  [Backport #9206]