alignment.c

 
#include <stdlib.h>
#include <winpr/config.h>
 
#include <winpr/crt.h>
#include <winpr/debug.h>
 
/* Data Alignment: http://msdn.microsoft.com/en-us/library/fs9stz4e/ */
 
#if !defined(_WIN32) || (defined(__MINGW32__) && !defined(_UCRT))
 
#include <stdint.h>
#include <limits.h>
 
#define WINPR_ALIGNED_MEM_SIGNATURE 0x0BA0BAB
 
#define WINPR_ALIGNED_MEM_STRUCT_FROM_PTR(_memptr) \
  (WINPR_ALIGNED_MEM*)(((size_t)(((BYTE*)(_memptr)) - sizeof(WINPR_ALIGNED_MEM))))
 
#include <stdlib.h>
 
#include "../log.h"
#define TAG WINPR_TAG("crt")
 
struct winpr_aligned_mem
{
  UINT32 sig;
  size_t size;
  void* base_addr;
};
typedef struct winpr_aligned_mem WINPR_ALIGNED_MEM;
 
#define get_aligned_mem_block(ptr) get_aligned_mem_block_((ptr), __func__, __FILE__, __LINE__)
 
WINPR_ATTR_NODISCARD
static inline WINPR_ALIGNED_MEM* get_aligned_mem_block_(void* memblock, const char* fkt,
                                                        const char* file, size_t line)
{
  if (!memblock)
    return nullptr;
 
  WINPR_ALIGNED_MEM* pMem = WINPR_ALIGNED_MEM_STRUCT_FROM_PTR(memblock);
  if (pMem->sig != WINPR_ALIGNED_MEM_SIGNATURE)
  {
    const DWORD level = WLOG_ERROR;
    wLog* log = WLog_Get(TAG);
    if (WLog_IsLevelActive(log, level))
    {
      WLog_PrintTextMessage(log, level, line, file, fkt,
                            "memory block was not allocated by _aligned_malloc!");
      winpr_log_backtrace_ex(log, WLOG_ERROR, 20);
    }
    return nullptr;
  }
 
  return pMem;
}
 
void* winpr_aligned_malloc(size_t size, size_t alignment)
{
  return winpr_aligned_offset_malloc(size, alignment, 0);
}
 
void* winpr_aligned_calloc(size_t count, size_t size, size_t alignment)
{
  return winpr_aligned_recalloc(nullptr, count, size, alignment);
}
 
void* winpr_aligned_realloc(void* memblock, size_t size, size_t alignment)
{
  return winpr_aligned_offset_realloc(memblock, size, alignment, 0);
}
 
void* winpr_aligned_recalloc(void* memblock, size_t num, size_t size, size_t alignment)
{
  return winpr_aligned_offset_recalloc(memblock, num, size, alignment, 0);
}
 
void* winpr_aligned_offset_malloc(size_t size, size_t alignment, size_t offset)
{
  size_t header = 0;
  size_t alignsize = 0;
  uintptr_t basesize = 0;
  void* base = nullptr;
  void* memblock = nullptr;
  WINPR_ALIGNED_MEM* pMem = nullptr;
 
  /* alignment must be a power of 2 */
  if (alignment % 2 == 1)
    return nullptr;
 
  /* offset must be less than size */
  if (offset >= size)
    return nullptr;
 
  /* minimum alignment is pointer size */
  if (alignment < sizeof(void*))
    alignment = sizeof(void*);
 
  if (alignment > SIZE_MAX - sizeof(WINPR_ALIGNED_MEM))
    return nullptr;
 
  header = sizeof(WINPR_ALIGNED_MEM) + alignment;
 
  if (size > SIZE_MAX - header)
    return nullptr;
 
  alignsize = size + header;
  /* malloc size + alignment to make sure we can align afterwards */
#if defined(_ISOC11_SOURCE)
  base = aligned_alloc(alignment, alignsize);
#elif defined(_POSIX_C_SOURCE) && (_POSIX_C_SOURCE >= 200112L) || (_XOPEN_SOURCE >= 600)
  if (posix_memalign(&base, alignment, alignsize) != 0)
    return nullptr;
#else
  base = malloc(alignsize);
#endif
  if (!base)
    return nullptr;
 
  basesize = (uintptr_t)base;
 
  if ((offset > UINTPTR_MAX) || (header > UINTPTR_MAX - offset) ||
      (basesize > UINTPTR_MAX - header - offset))
  {
    free(base);
    return nullptr;
  }
 
  memblock = (void*)(((basesize + header + offset) & ~(alignment - 1)) - offset);
  pMem = WINPR_ALIGNED_MEM_STRUCT_FROM_PTR(memblock);
  pMem->sig = WINPR_ALIGNED_MEM_SIGNATURE;
  pMem->base_addr = base;
  pMem->size = size;
  return memblock;
}
 
void* winpr_aligned_offset_realloc(void* memblock, size_t size, size_t alignment, size_t offset)
{
  size_t copySize = 0;
 
  if (!memblock)
    return winpr_aligned_offset_malloc(size, alignment, offset);
 
  WINPR_ALIGNED_MEM* pMem = get_aligned_mem_block(memblock);
  if (!pMem)
    return nullptr;
 
  if (size == 0)
  {
    winpr_aligned_free(memblock);
    return nullptr;
  }
 
  void* newMemblock = winpr_aligned_offset_malloc(size, alignment, offset);
  if (!newMemblock)
    return nullptr;
 
  WINPR_ALIGNED_MEM* pNewMem = WINPR_ALIGNED_MEM_STRUCT_FROM_PTR(newMemblock);
  copySize = (pNewMem->size < pMem->size) ? pNewMem->size : pMem->size;
  CopyMemory(newMemblock, memblock, copySize);
  winpr_aligned_free(memblock);
  return newMemblock;
}
 
WINPR_ATTR_NODISCARD static inline size_t cMIN(size_t a, size_t b)
{
  if (a > b)
    return b;
  return a;
}
 
void* winpr_aligned_offset_recalloc(void* memblock, size_t num, size_t size, size_t alignment,
                                    size_t offset)
{
  char* newMemblock = nullptr;
  WINPR_ALIGNED_MEM* pNewMem = nullptr;
 
  if (!memblock)
  {
    newMemblock = winpr_aligned_offset_malloc(size * num, alignment, offset);
 
    if (newMemblock)
    {
      pNewMem = WINPR_ALIGNED_MEM_STRUCT_FROM_PTR(newMemblock);
      ZeroMemory(newMemblock, pNewMem->size);
    }
 
    return newMemblock;
  }
 
  WINPR_ALIGNED_MEM* pMem = get_aligned_mem_block(memblock);
  if (!pMem)
    goto fail;
 
  if ((num == 0) || (size == 0))
    goto fail;
 
  if (pMem->size > (1ull * num * size) + alignment)
    return memblock;
 
  newMemblock = winpr_aligned_offset_malloc(size * num, alignment, offset);
 
  if (!newMemblock)
    goto fail;
 
  pNewMem = WINPR_ALIGNED_MEM_STRUCT_FROM_PTR(newMemblock);
  {
    const size_t csize = cMIN(pMem->size, pNewMem->size);
    memcpy(newMemblock, memblock, csize);
    ZeroMemory(newMemblock + csize, pNewMem->size - csize);
  }
fail:
  winpr_aligned_free(memblock);
  return newMemblock;
}
 
size_t winpr_aligned_msize(void* memblock, WINPR_ATTR_UNUSED size_t alignment,
                           WINPR_ATTR_UNUSED size_t offset)
{
  WINPR_ALIGNED_MEM* pMem = get_aligned_mem_block(memblock);
 
  if (!pMem)
    return 0;
 
  return pMem->size;
}
 
void winpr_aligned_free(void* memblock)
{
  WINPR_ALIGNED_MEM* pMem = get_aligned_mem_block(memblock);
 
  if (!pMem)
    return;
 
  free(pMem->base_addr);
}
 
#endif /* _WIN32 */