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/src/debug.cpp b/src/debug.cpp
index 2e88b85..28a1f70 100644
--- a/src/debug.cpp
+++ b/src/debug.cpp
@@ -203,8 +203,8 @@
i->__c_ = c;
}
-__c_node*
-__libcpp_db::__insert_c(void* __c)
+void
+__libcpp_db::__insert_c(void* __c, __libcpp_db::_InsertConstruct *__fn)
{
#ifndef _LIBCPP_HAS_NO_THREADS
WLock _(mut());
@@ -234,15 +234,12 @@
}
size_t hc = hash<void*>()(__c) % static_cast<size_t>(__cend_ - __cbeg_);
__c_node* p = __cbeg_[hc];
- __c_node* r = __cbeg_[hc] =
- static_cast<__c_node*>(malloc(sizeof(__c_node)));
- if (__cbeg_[hc] == nullptr)
- __throw_bad_alloc();
+ void *buf = malloc(sizeof(__c_node));
+ if (buf == nullptr)
+ __throw_bad_alloc();
+ __cbeg_[hc] = __fn(buf, __c, p);
- r->__c_ = __c;
- r->__next_ = p;
++__csz_;
- return r;
}
void