Files
clang-p2996/libcxx/src/debug.cpp
Eric Fiselier 1c014d75b4 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
2019-03-05 02:10:31 +00:00

615 lines
14 KiB
C++

//===-------------------------- debug.cpp ---------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "__config"
#include "__debug"
#include "functional"
#include "algorithm"
#include "string"
#include "cstdio"
#include "__hash_table"
#include "mutex"
_LIBCPP_BEGIN_NAMESPACE_STD
static std::string make_what_str(__libcpp_debug_info const& info) {
string msg = info.__file_;
msg += ":" + to_string(info.__line_) + ": _LIBCPP_ASSERT '";
msg += info.__pred_;
msg += "' failed. ";
msg += info.__msg_;
return msg;
}
_LIBCPP_SAFE_STATIC __libcpp_debug_function_type
__libcpp_debug_function = __libcpp_abort_debug_function;
bool __libcpp_set_debug_function(__libcpp_debug_function_type __func) {
__libcpp_debug_function = __func;
return true;
}
_LIBCPP_NORETURN void __libcpp_abort_debug_function(__libcpp_debug_info const& info) {
std::fprintf(stderr, "%s\n", make_what_str(info).c_str());
std::abort();
}
_LIBCPP_NORETURN void __libcpp_throw_debug_function(__libcpp_debug_info const& info) {
#ifndef _LIBCPP_NO_EXCEPTIONS
throw __libcpp_debug_exception(info);
#else
__libcpp_abort_debug_function(info);
#endif
}
struct __libcpp_debug_exception::__libcpp_debug_exception_imp {
__libcpp_debug_info __info_;
std::string __what_str_;
};
__libcpp_debug_exception::__libcpp_debug_exception() _NOEXCEPT
: __imp_(nullptr) {
}
__libcpp_debug_exception::__libcpp_debug_exception(
__libcpp_debug_info const& info) : __imp_(new __libcpp_debug_exception_imp)
{
__imp_->__info_ = info;
__imp_->__what_str_ = make_what_str(info);
}
__libcpp_debug_exception::__libcpp_debug_exception(
__libcpp_debug_exception const& other) : __imp_(nullptr) {
if (other.__imp_)
__imp_ = new __libcpp_debug_exception_imp(*other.__imp_);
}
__libcpp_debug_exception::~__libcpp_debug_exception() _NOEXCEPT {
if (__imp_)
delete __imp_;
}
const char* __libcpp_debug_exception::what() const _NOEXCEPT {
if (__imp_)
return __imp_->__what_str_.c_str();
return "__libcpp_debug_exception";
}
_LIBCPP_FUNC_VIS
__libcpp_db*
__get_db()
{
static __libcpp_db db;
return &db;
}
_LIBCPP_FUNC_VIS
const __libcpp_db*
__get_const_db()
{
return __get_db();
}
namespace
{
#ifndef _LIBCPP_HAS_NO_THREADS
typedef mutex mutex_type;
typedef lock_guard<mutex_type> WLock;
typedef lock_guard<mutex_type> RLock;
mutex_type&
mut()
{
static mutex_type m;
return m;
}
#endif // !_LIBCPP_HAS_NO_THREADS
} // unnamed namespace
__i_node::~__i_node()
{
if (__next_)
{
__next_->~__i_node();
free(__next_);
}
}
__c_node::~__c_node()
{
free(beg_);
if (__next_)
{
__next_->~__c_node();
free(__next_);
}
}
__libcpp_db::__libcpp_db()
: __cbeg_(nullptr),
__cend_(nullptr),
__csz_(0),
__ibeg_(nullptr),
__iend_(nullptr),
__isz_(0)
{
}
__libcpp_db::~__libcpp_db()
{
if (__cbeg_)
{
for (__c_node** p = __cbeg_; p != __cend_; ++p)
{
if (*p != nullptr)
{
(*p)->~__c_node();
free(*p);
}
}
free(__cbeg_);
}
if (__ibeg_)
{
for (__i_node** p = __ibeg_; p != __iend_; ++p)
{
if (*p != nullptr)
{
(*p)->~__i_node();
free(*p);
}
}
free(__ibeg_);
}
}
void*
__libcpp_db::__find_c_from_i(void* __i) const
{
#ifndef _LIBCPP_HAS_NO_THREADS
RLock _(mut());
#endif
__i_node* i = __find_iterator(__i);
_LIBCPP_ASSERT(i != nullptr, "iterator not found in debug database.");
return i->__c_ != nullptr ? i->__c_->__c_ : nullptr;
}
void
__libcpp_db::__insert_ic(void* __i, const void* __c)
{
#ifndef _LIBCPP_HAS_NO_THREADS
WLock _(mut());
#endif
if (__cbeg_ == __cend_)
return;
size_t hc = hash<const void*>()(__c) % static_cast<size_t>(__cend_ - __cbeg_);
__c_node* c = __cbeg_[hc];
if (c == nullptr)
return;
while (c->__c_ != __c)
{
c = c->__next_;
if (c == nullptr)
return;
}
__i_node* i = __insert_iterator(__i);
c->__add(i);
i->__c_ = c;
}
void
__libcpp_db::__insert_c(void* __c, __libcpp_db::_InsertConstruct *__fn)
{
#ifndef _LIBCPP_HAS_NO_THREADS
WLock _(mut());
#endif
if (__csz_ + 1 > static_cast<size_t>(__cend_ - __cbeg_))
{
size_t nc = __next_prime(2*static_cast<size_t>(__cend_ - __cbeg_) + 1);
__c_node** cbeg = static_cast<__c_node**>(calloc(nc, sizeof(void*)));
if (cbeg == nullptr)
__throw_bad_alloc();
for (__c_node** p = __cbeg_; p != __cend_; ++p)
{
__c_node* q = *p;
while (q != nullptr)
{
size_t h = hash<void*>()(q->__c_) % nc;
__c_node* r = q->__next_;
q->__next_ = cbeg[h];
cbeg[h] = q;
q = r;
}
}
free(__cbeg_);
__cbeg_ = cbeg;
__cend_ = __cbeg_ + nc;
}
size_t hc = hash<void*>()(__c) % static_cast<size_t>(__cend_ - __cbeg_);
__c_node* p = __cbeg_[hc];
void *buf = malloc(sizeof(__c_node));
if (buf == nullptr)
__throw_bad_alloc();
__cbeg_[hc] = __fn(buf, __c, p);
++__csz_;
}
void
__libcpp_db::__erase_i(void* __i)
{
#ifndef _LIBCPP_HAS_NO_THREADS
WLock _(mut());
#endif
if (__ibeg_ != __iend_)
{
size_t hi = hash<void*>()(__i) % static_cast<size_t>(__iend_ - __ibeg_);
__i_node* p = __ibeg_[hi];
if (p != nullptr)
{
__i_node* q = nullptr;
while (p->__i_ != __i)
{
q = p;
p = p->__next_;
if (p == nullptr)
return;
}
if (q == nullptr)
__ibeg_[hi] = p->__next_;
else
q->__next_ = p->__next_;
__c_node* c = p->__c_;
--__isz_;
if (c != nullptr)
c->__remove(p);
free(p);
}
}
}
void
__libcpp_db::__invalidate_all(void* __c)
{
#ifndef _LIBCPP_HAS_NO_THREADS
WLock _(mut());
#endif
if (__cend_ != __cbeg_)
{
size_t hc = hash<void*>()(__c) % static_cast<size_t>(__cend_ - __cbeg_);
__c_node* p = __cbeg_[hc];
if (p == nullptr)
return;
while (p->__c_ != __c)
{
p = p->__next_;
if (p == nullptr)
return;
}
while (p->end_ != p->beg_)
{
--p->end_;
(*p->end_)->__c_ = nullptr;
}
}
}
__c_node*
__libcpp_db::__find_c_and_lock(void* __c) const
{
#ifndef _LIBCPP_HAS_NO_THREADS
mut().lock();
#endif
if (__cend_ == __cbeg_)
{
#ifndef _LIBCPP_HAS_NO_THREADS
mut().unlock();
#endif
return nullptr;
}
size_t hc = hash<void*>()(__c) % static_cast<size_t>(__cend_ - __cbeg_);
__c_node* p = __cbeg_[hc];
if (p == nullptr)
{
#ifndef _LIBCPP_HAS_NO_THREADS
mut().unlock();
#endif
return nullptr;
}
while (p->__c_ != __c)
{
p = p->__next_;
if (p == nullptr)
{
#ifndef _LIBCPP_HAS_NO_THREADS
mut().unlock();
#endif
return nullptr;
}
}
return p;
}
__c_node*
__libcpp_db::__find_c(void* __c) const
{
size_t hc = hash<void*>()(__c) % static_cast<size_t>(__cend_ - __cbeg_);
__c_node* p = __cbeg_[hc];
_LIBCPP_ASSERT(p != nullptr, "debug mode internal logic error __find_c A");
while (p->__c_ != __c)
{
p = p->__next_;
_LIBCPP_ASSERT(p != nullptr, "debug mode internal logic error __find_c B");
}
return p;
}
void
__libcpp_db::unlock() const
{
#ifndef _LIBCPP_HAS_NO_THREADS
mut().unlock();
#endif
}
void
__libcpp_db::__erase_c(void* __c)
{
#ifndef _LIBCPP_HAS_NO_THREADS
WLock _(mut());
#endif
if (__cend_ != __cbeg_)
{
size_t hc = hash<void*>()(__c) % static_cast<size_t>(__cend_ - __cbeg_);
__c_node* p = __cbeg_[hc];
if (p == nullptr)
return;
__c_node* q = nullptr;
_LIBCPP_ASSERT(p != nullptr, "debug mode internal logic error __erase_c A");
while (p->__c_ != __c)
{
q = p;
p = p->__next_;
if (p == nullptr)
return;
_LIBCPP_ASSERT(p != nullptr, "debug mode internal logic error __erase_c B");
}
if (q == nullptr)
__cbeg_[hc] = p->__next_;
else
q->__next_ = p->__next_;
while (p->end_ != p->beg_)
{
--p->end_;
(*p->end_)->__c_ = nullptr;
}
free(p->beg_);
free(p);
--__csz_;
}
}
void
__libcpp_db::__iterator_copy(void* __i, const void* __i0)
{
#ifndef _LIBCPP_HAS_NO_THREADS
WLock _(mut());
#endif
__i_node* i = __find_iterator(__i);
__i_node* i0 = __find_iterator(__i0);
__c_node* c0 = i0 != nullptr ? i0->__c_ : nullptr;
if (i == nullptr && i0 != nullptr)
i = __insert_iterator(__i);
__c_node* c = i != nullptr ? i->__c_ : nullptr;
if (c != c0)
{
if (c != nullptr)
c->__remove(i);
if (i != nullptr)
{
i->__c_ = nullptr;
if (c0 != nullptr)
{
i->__c_ = c0;
i->__c_->__add(i);
}
}
}
}
bool
__libcpp_db::__dereferenceable(const void* __i) const
{
#ifndef _LIBCPP_HAS_NO_THREADS
RLock _(mut());
#endif
__i_node* i = __find_iterator(__i);
return i != nullptr && i->__c_ != nullptr && i->__c_->__dereferenceable(__i);
}
bool
__libcpp_db::__decrementable(const void* __i) const
{
#ifndef _LIBCPP_HAS_NO_THREADS
RLock _(mut());
#endif
__i_node* i = __find_iterator(__i);
return i != nullptr && i->__c_ != nullptr && i->__c_->__decrementable(__i);
}
bool
__libcpp_db::__addable(const void* __i, ptrdiff_t __n) const
{
#ifndef _LIBCPP_HAS_NO_THREADS
RLock _(mut());
#endif
__i_node* i = __find_iterator(__i);
return i != nullptr && i->__c_ != nullptr && i->__c_->__addable(__i, __n);
}
bool
__libcpp_db::__subscriptable(const void* __i, ptrdiff_t __n) const
{
#ifndef _LIBCPP_HAS_NO_THREADS
RLock _(mut());
#endif
__i_node* i = __find_iterator(__i);
return i != nullptr && i->__c_ != nullptr && i->__c_->__subscriptable(__i, __n);
}
bool
__libcpp_db::__less_than_comparable(const void* __i, const void* __j) const
{
#ifndef _LIBCPP_HAS_NO_THREADS
RLock _(mut());
#endif
__i_node* i = __find_iterator(__i);
__i_node* j = __find_iterator(__j);
__c_node* ci = i != nullptr ? i->__c_ : nullptr;
__c_node* cj = j != nullptr ? j->__c_ : nullptr;
return ci != nullptr && ci == cj;
}
void
__libcpp_db::swap(void* c1, void* c2)
{
#ifndef _LIBCPP_HAS_NO_THREADS
WLock _(mut());
#endif
size_t hc = hash<void*>()(c1) % static_cast<size_t>(__cend_ - __cbeg_);
__c_node* p1 = __cbeg_[hc];
_LIBCPP_ASSERT(p1 != nullptr, "debug mode internal logic error swap A");
while (p1->__c_ != c1)
{
p1 = p1->__next_;
_LIBCPP_ASSERT(p1 != nullptr, "debug mode internal logic error swap B");
}
hc = hash<void*>()(c2) % static_cast<size_t>(__cend_ - __cbeg_);
__c_node* p2 = __cbeg_[hc];
_LIBCPP_ASSERT(p2 != nullptr, "debug mode internal logic error swap C");
while (p2->__c_ != c2)
{
p2 = p2->__next_;
_LIBCPP_ASSERT(p2 != nullptr, "debug mode internal logic error swap D");
}
std::swap(p1->beg_, p2->beg_);
std::swap(p1->end_, p2->end_);
std::swap(p1->cap_, p2->cap_);
for (__i_node** p = p1->beg_; p != p1->end_; ++p)
(*p)->__c_ = p1;
for (__i_node** p = p2->beg_; p != p2->end_; ++p)
(*p)->__c_ = p2;
}
void
__libcpp_db::__insert_i(void* __i)
{
#ifndef _LIBCPP_HAS_NO_THREADS
WLock _(mut());
#endif
__insert_iterator(__i);
}
void
__c_node::__add(__i_node* i)
{
if (end_ == cap_)
{
size_t nc = 2*static_cast<size_t>(cap_ - beg_);
if (nc == 0)
nc = 1;
__i_node** beg =
static_cast<__i_node**>(malloc(nc * sizeof(__i_node*)));
if (beg == nullptr)
__throw_bad_alloc();
if (nc > 1)
memcpy(beg, beg_, nc/2*sizeof(__i_node*));
free(beg_);
beg_ = beg;
end_ = beg_ + nc/2;
cap_ = beg_ + nc;
}
*end_++ = i;
}
// private api
_LIBCPP_HIDDEN
__i_node*
__libcpp_db::__insert_iterator(void* __i)
{
if (__isz_ + 1 > static_cast<size_t>(__iend_ - __ibeg_))
{
size_t nc = __next_prime(2*static_cast<size_t>(__iend_ - __ibeg_) + 1);
__i_node** ibeg = static_cast<__i_node**>(calloc(nc, sizeof(void*)));
if (ibeg == nullptr)
__throw_bad_alloc();
for (__i_node** p = __ibeg_; p != __iend_; ++p)
{
__i_node* q = *p;
while (q != nullptr)
{
size_t h = hash<void*>()(q->__i_) % nc;
__i_node* r = q->__next_;
q->__next_ = ibeg[h];
ibeg[h] = q;
q = r;
}
}
free(__ibeg_);
__ibeg_ = ibeg;
__iend_ = __ibeg_ + nc;
}
size_t hi = hash<void*>()(__i) % static_cast<size_t>(__iend_ - __ibeg_);
__i_node* p = __ibeg_[hi];
__i_node* r = __ibeg_[hi] =
static_cast<__i_node*>(malloc(sizeof(__i_node)));
if (r == nullptr)
__throw_bad_alloc();
::new(r) __i_node(__i, p, nullptr);
++__isz_;
return r;
}
_LIBCPP_HIDDEN
__i_node*
__libcpp_db::__find_iterator(const void* __i) const
{
__i_node* r = nullptr;
if (__ibeg_ != __iend_)
{
size_t h = hash<const void*>()(__i) % static_cast<size_t>(__iend_ - __ibeg_);
for (__i_node* nd = __ibeg_[h]; nd != nullptr; nd = nd->__next_)
{
if (nd->__i_ == __i)
{
r = nd;
break;
}
}
}
return r;
}
_LIBCPP_HIDDEN
void
__c_node::__remove(__i_node* p)
{
__i_node** r = find(beg_, end_, p);
_LIBCPP_ASSERT(r != end_, "debug mode internal logic error __c_node::__remove");
if (--end_ != r)
memmove(r, r+1, static_cast<size_t>(end_ - r)*sizeof(__i_node*));
}
_LIBCPP_END_NAMESPACE_STD