[committed] libstdc++: Make allocators throw bad_array_new_length on overflow [LWG 3190]
Jonathan Wakely
jwakely@redhat.com
Mon Oct 5 15:06:52 GMT 2020
std::allocator and std::pmr::polymorphic_allocator should throw
std::bad_array_new_length from their allocate member functions if the
number of bytes required cannot be represented in std::size_t.
libstdc++-v3/ChangeLog:
* config/abi/pre/gnu.ver: Add new symbol.
* include/bits/functexcept.h (__throw_bad_array_new_length):
Declare new function.
* include/ext/malloc_allocator.h (malloc_allocator::allocate):
Throw bad_array_new_length for impossible sizes (LWG 3190).
* include/ext/new_allocator.h (new_allocator::allocate):
Likewise.
* include/std/memory_resource (polymorphic_allocator::allocate)
(polymorphic_allocator::allocate_object): Use new function,
__throw_bad_array_new_length.
* src/c++11/functexcept.cc (__throw_bad_array_new_length):
Define.
* testsuite/20_util/allocator/lwg3190.cc: New test.
Tested powerpc64le-linux. Committed to trunk.
-------------- next part --------------
commit f92a504fdd943527687faf9557e0b39ff7fe6125
Author: Jonathan Wakely <jwakely@redhat.com>
Date: Mon Oct 5 15:16:58 2020
libstdc++: Make allocators throw bad_array_new_length on overflow [LWG 3190]
std::allocator and std::pmr::polymorphic_allocator should throw
std::bad_array_new_length from their allocate member functions if the
number of bytes required cannot be represented in std::size_t.
libstdc++-v3/ChangeLog:
* config/abi/pre/gnu.ver: Add new symbol.
* include/bits/functexcept.h (__throw_bad_array_new_length):
Declare new function.
* include/ext/malloc_allocator.h (malloc_allocator::allocate):
Throw bad_array_new_length for impossible sizes (LWG 3190).
* include/ext/new_allocator.h (new_allocator::allocate):
Likewise.
* include/std/memory_resource (polymorphic_allocator::allocate)
(polymorphic_allocator::allocate_object): Use new function,
__throw_bad_array_new_length.
* src/c++11/functexcept.cc (__throw_bad_array_new_length):
Define.
* testsuite/20_util/allocator/lwg3190.cc: New test.
diff --git a/libstdc++-v3/config/abi/pre/gnu.ver b/libstdc++-v3/config/abi/pre/gnu.ver
index 87a48a21f53..6a2b2da33f5 100644
--- a/libstdc++-v3/config/abi/pre/gnu.ver
+++ b/libstdc++-v3/config/abi/pre/gnu.ver
@@ -2322,6 +2322,9 @@ GLIBCXX_3.4.29 {
# std::__atomic_futex_unsigned_base::_M_futex_wait_until_steady
_ZNSt28__atomic_futex_unsigned_base26_M_futex_wait_until_steady*;
+ # std::__throw_bad_array_new_length()
+ _ZSt28__throw_bad_array_new_lengthv;
+
} GLIBCXX_3.4.28;
# Symbols in the support library (libsupc++) have their own tag.
diff --git a/libstdc++-v3/include/bits/functexcept.h b/libstdc++-v3/include/bits/functexcept.h
index 52eef2bb2c6..f6079e2a535 100644
--- a/libstdc++-v3/include/bits/functexcept.h
+++ b/libstdc++-v3/include/bits/functexcept.h
@@ -51,6 +51,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
void
__throw_bad_alloc(void) __attribute__((__noreturn__));
+ void
+ __throw_bad_array_new_length(void) __attribute__((__noreturn__));
+
// Helper for exception objects in <typeinfo>
void
__throw_bad_cast(void) __attribute__((__noreturn__));
diff --git a/libstdc++-v3/include/ext/malloc_allocator.h b/libstdc++-v3/include/ext/malloc_allocator.h
index 366c766f25b..dd45470c456 100644
--- a/libstdc++-v3/include/ext/malloc_allocator.h
+++ b/libstdc++-v3/include/ext/malloc_allocator.h
@@ -102,8 +102,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_Tp*
allocate(size_type __n, const void* = 0)
{
- if (__n > this->_M_max_size())
- std::__throw_bad_alloc();
+ if (__builtin_expect(__n > this->_M_max_size(), false))
+ {
+ // _GLIBCXX_RESOLVE_LIB_DEFECTS
+ // 3190. allocator::allocate sometimes returns too little storage
+ if (__n > (std::size_t(-1) / sizeof(_Tp)))
+ std::__throw_bad_array_new_length();
+ std::__throw_bad_alloc();
+ }
_Tp* __ret = 0;
#if __cpp_aligned_new
diff --git a/libstdc++-v3/include/ext/new_allocator.h b/libstdc++-v3/include/ext/new_allocator.h
index 2e21a98409f..a43c8d9b6fb 100644
--- a/libstdc++-v3/include/ext/new_allocator.h
+++ b/libstdc++-v3/include/ext/new_allocator.h
@@ -102,8 +102,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_GLIBCXX_NODISCARD _Tp*
allocate(size_type __n, const void* = static_cast<const void*>(0))
{
- if (__n > this->_M_max_size())
- std::__throw_bad_alloc();
+ if (__builtin_expect(__n > this->_M_max_size(), false))
+ {
+ // _GLIBCXX_RESOLVE_LIB_DEFECTS
+ // 3190. allocator::allocate sometimes returns too little storage
+ if (__n > (std::size_t(-1) / sizeof(_Tp)))
+ std::__throw_bad_array_new_length();
+ std::__throw_bad_alloc();
+ }
#if __cpp_aligned_new
if (alignof(_Tp) > __STDCPP_DEFAULT_NEW_ALIGNMENT__)
diff --git a/libstdc++-v3/include/std/memory_resource b/libstdc++-v3/include/std/memory_resource
index 3db22978294..6491179a7c5 100644
--- a/libstdc++-v3/include/std/memory_resource
+++ b/libstdc++-v3/include/std/memory_resource
@@ -168,8 +168,8 @@ namespace pmr
allocate(size_t __n)
__attribute__((__returns_nonnull__))
{
- if (__n > (__gnu_cxx::__int_traits<size_t>::__max / sizeof(_Tp)))
- _GLIBCXX_THROW_OR_ABORT(bad_array_new_length());
+ if ((__gnu_cxx::__int_traits<size_t>::__max / sizeof(_Tp)) < __n)
+ std::__throw_bad_array_new_length();
return static_cast<_Tp*>(_M_resource->allocate(__n * sizeof(_Tp),
alignof(_Tp)));
}
@@ -195,7 +195,7 @@ namespace pmr
allocate_object(size_t __n = 1)
{
if ((__gnu_cxx::__int_traits<size_t>::__max / sizeof(_Up)) < __n)
- _GLIBCXX_THROW_OR_ABORT(bad_array_new_length());
+ std::__throw_bad_array_new_length();
return static_cast<_Up*>(allocate_bytes(__n * sizeof(_Up),
alignof(_Up)));
}
diff --git a/libstdc++-v3/src/c++11/functexcept.cc b/libstdc++-v3/src/c++11/functexcept.cc
index d43167d6f88..b5da1746c09 100644
--- a/libstdc++-v3/src/c++11/functexcept.cc
+++ b/libstdc++-v3/src/c++11/functexcept.cc
@@ -53,6 +53,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
__throw_bad_alloc()
{ _GLIBCXX_THROW_OR_ABORT(bad_alloc()); }
+ void
+ __throw_bad_array_new_length()
+ { _GLIBCXX_THROW_OR_ABORT(bad_array_new_length()); }
+
void
__throw_bad_cast()
{ _GLIBCXX_THROW_OR_ABORT(bad_cast()); }
diff --git a/libstdc++-v3/testsuite/20_util/allocator/lwg3190.cc b/libstdc++-v3/testsuite/20_util/allocator/lwg3190.cc
new file mode 100644
index 00000000000..955f05b22a1
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/allocator/lwg3190.cc
@@ -0,0 +1,53 @@
+// Copyright (C) 2020 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-do run { target c++11 } }
+
+#include <memory>
+#include <new>
+#include <limits>
+#include <testsuite_hooks.h>
+
+// LWG 3190. std::allocator::allocate sometimes returns too little storage
+
+void
+test01()
+{
+ struct A { char biiiiig[1 << 16]; };
+ std::allocator<A> a;
+ try
+ {
+ std::size_t max = std::numeric_limits<std::size_t>::max() / sizeof(A);
+ A* p = a.allocate(max + 1);
+ throw p;
+ }
+#if __cplusplus >= 201103L
+ catch (const std::bad_array_new_length&)
+ {
+ }
+#endif
+ catch (const std::bad_alloc&)
+ {
+ VERIFY( __cplusplus < 201103L );
+ }
+}
+
+int
+main()
+{
+ test01();
+}
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