allocate.cpp
// allocate.cpp - written and placed in the public domain by Jeffrey Walton
// The functions in allocate.h and allocate.cpp were originally in misc.h
// and misc.cpp. They were extracted in September 2019 to sidestep a circular
// dependency with misc.h and secblock.h.
#include "pch.h"
#include "config.h"
#ifndef CRYPTOPP_IMPORTS
#include "allocate.h"
#include "stdcpp.h"
#include "misc.h"
#include "trap.h"
// for memalign
#if defined(CRYPTOPP_MEMALIGN_AVAILABLE) || defined(CRYPTOPP_MM_MALLOC_AVAILABLE) || defined(QNX)
# include <malloc.h>
#endif
// for posix_memalign
#if defined(CRYPTOPP_POSIX_MEMALIGN_AVAILABLE)
# include <stdlib.h>
#endif
NAMESPACE_BEGIN(CryptoPP)
void CallNewHandler()
{
using std::new_handler;
using std::set_new_handler;
new_handler newHandler = set_new_handler(NULLPTR);
if (newHandler)
set_new_handler(newHandler);
if (newHandler)
newHandler();
else
throw std::bad_alloc();
}
void * AlignedAllocate(size_t size)
{
byte *p;
#if defined(CRYPTOPP_MM_MALLOC_AVAILABLE)
while ((p = (byte *)_mm_malloc(size, 16)) == NULLPTR)
#elif defined(CRYPTOPP_MEMALIGN_AVAILABLE)
while ((p = (byte *)memalign(16, size)) == NULLPTR)
#elif defined(CRYPTOPP_MALLOC_ALIGNMENT_IS_16)
while ((p = (byte *)malloc(size)) == NULLPTR)
#elif defined(CRYPTOPP_POSIX_MEMALIGN_AVAILABLE)
while (posix_memalign(reinterpret_cast<void**>(&p), 16, size) != 0)
#else
while ((p = (byte *)malloc(size + 16)) == NULLPTR)
#endif
CallNewHandler();
#ifdef CRYPTOPP_NO_ALIGNED_ALLOC
size_t adjustment = 16-((size_t)p%16);
CRYPTOPP_ASSERT(adjustment > 0);
p += adjustment;
p[-1] = (byte)adjustment;
#endif
// If this assert fires then there are problems that need
// to be fixed. Please open a bug report.
CRYPTOPP_ASSERT(IsAlignedOn(p, 16));
return p;
}
void AlignedDeallocate(void *p)
{
// Guard pointer due to crash on AIX when CRYPTOPP_NO_ALIGNED_ALLOC
// is in effect. The guard was previously in place in SecBlock,
// but it was removed at f4d68353ca7c as part of GH #875.
CRYPTOPP_ASSERT(p);
if (p != NULLPTR)
{
#ifdef CRYPTOPP_MM_MALLOC_AVAILABLE
_mm_free(p);
#elif defined(CRYPTOPP_NO_ALIGNED_ALLOC)
p = (byte *)p - ((byte *)p)[-1];
free(p);
#else
free(p);
#endif
}
}
void * UnalignedAllocate(size_t size)
{
void *p;
while ((p = malloc(size)) == NULLPTR)
CallNewHandler();
return p;
}
void UnalignedDeallocate(void *p)
{
free(p);
}
NAMESPACE_END
#endif // CRYPTOPP_IMPORTS
allocate.h
Functions for allocating aligned buffers.
AlignedDeallocate
CRYPTOPP_DLL void AlignedDeallocate(void *ptr)
Frees a buffer allocated with AlignedAllocate.
CallNewHandler
CRYPTOPP_DLL void CallNewHandler()
Attempts to reclaim unused memory.
UnalignedAllocate
CRYPTOPP_DLL void * UnalignedAllocate(size_t size)
Allocates a buffer.
UnalignedDeallocate
CRYPTOPP_DLL void UnalignedDeallocate(void *ptr)
Frees a buffer allocated with UnalignedAllocate.
AlignedAllocate
CRYPTOPP_DLL void * AlignedAllocate(size_t size)
Allocates a buffer on 16-byte boundary.
config.h
Library configuration file.
byte
unsigned char byte
8-bit unsigned datatype
Definition: config_int.h:56
misc.h
Utility functions for the Crypto++ library.
IsAlignedOn
bool IsAlignedOn(const void *ptr, unsigned int alignment)
Determines whether ptr is aligned to a minimum value.
Definition: misc.h:1226
CryptoPP
Crypto++ library namespace.
pch.h
Precompiled header file.
stdcpp.h
Common C++ header files.
trap.h
Debugging and diagnostic assertions.
CRYPTOPP_ASSERT
#define CRYPTOPP_ASSERT(exp)
Debugging and diagnostic assertion.
Definition: trap.h:68