Fix -fsanitize=vptr badness in <__debug>
Summary:
This patch fixes a lifetime bug when inserting a new container into the debug database. It is
diagnosed by UBSAN when debug mode is enabled. This patch corrects how nodes are constructed
during insertion.
The fix requires unconditionally breaking the debug mode ABI. Users should not expect ABI
stability from debug mode.
Reviewers: ldionne, serge-sans-paille, EricWF
Reviewed By: EricWF
Subscribers: mclow.lists, christof, libcxx-commits
Tags: #libc
Differential Revision: https://reviews.llvm.org/D58011
llvm-svn: 355367
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: 1c014d75b4cdcfab5cef304e5f9c5def96468751
diff --git a/include/__debug b/include/__debug
index 6ccb72c..281cf66 100644
--- a/include/__debug
+++ b/include/__debug
@@ -250,16 +250,22 @@
__db_c_const_iterator __c_end() const;
__db_i_const_iterator __i_end() const;
+ typedef __c_node*(_InsertConstruct)(void*, void*, __c_node*);
+
+ template <class _Cont>
+ _LIBCPP_INLINE_VISIBILITY static __c_node* __create_C_node(void *__mem, void *__c, __c_node *__next) {
+ return ::new(__mem) _C_node<_Cont>(__c, __next);
+ }
+
template <class _Cont>
_LIBCPP_INLINE_VISIBILITY
void __insert_c(_Cont* __c)
{
- __c_node* __n = __insert_c(static_cast<void*>(__c));
- ::new(__n) _C_node<_Cont>(__n->__c_, __n->__next_);
+ __insert_c(static_cast<void*>(__c), &__create_C_node<_Cont>);
}
void __insert_i(void* __i);
- __c_node* __insert_c(void* __c);
+ void __insert_c(void* __c, _InsertConstruct* __fn);
void __erase_c(void* __c);
void __insert_ic(void* __i, const void* __c);