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fixed 64-bit 4 GB boundary problem #67

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fixed 64-bit 4 GB boundary problem #67

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ccfa32a
fixed 64-bit 4 GB boundary problem
tobias-loew May 13, 2017
95de93d
Merge pull request #1 from tobias-loew/fix_64_bit_4GB_boundary_problem
tobias-loew May 13, 2017
34a0a11
added struct
tobias-loew May 13, 2017
d985eb5
Merge pull request #2 from tobias-loew/fix_64_bit_boundary_problem_3
tobias-loew May 13, 2017
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67 changes: 67 additions & 0 deletions MemoryModule.c
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Original file line number Diff line number Diff line change
Expand Up @@ -59,6 +59,15 @@
typedef BOOL (WINAPI *DllEntryProc)(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpReserved);
typedef int (WINAPI *ExeEntryProc)(void);

#ifdef _WIN64
// simple linked list to store memory blocks that span the 4GB boundary
// (which can't be used as memory for memorymodule)
typedef struct tagPOINTER_LIST{
struct tagPOINTER_LIST* next;
unsigned char *address;
}POINTER_LIST;
#endif

typedef struct {
PIMAGE_NT_HEADERS headers;
unsigned char *codeBase;
Expand All @@ -75,6 +84,9 @@ typedef struct {
void *userdata;
ExeEntryProc exeEntry;
DWORD pageSize;
#ifdef _WIN64
POINTER_LIST* blockedMemory;
#endif
} MEMORYMODULE, *PMEMORYMODULE;

typedef struct {
Expand Down Expand Up @@ -125,6 +137,18 @@ OutputLastError(const char *msg)
#endif
}

#ifdef _WIN64
static void FreePointerList(POINTER_LIST* head, CustomFreeFunc freeMemory, void* userdata) {
POINTER_LIST* node = head;
while(node != NULL) {
POINTER_LIST* current = node;
freeMemory(current->address, 0, MEM_RELEASE, userdata);
current = current->next;
free(node);
}
}
#endif

static BOOL
CheckSize(size_t size, size_t expected) {
if (size < expected) {
Expand Down Expand Up @@ -523,6 +547,9 @@ HMEMORYMODULE MemoryLoadLibraryEx(const void *data, size_t size,
size_t optionalSectionSize;
size_t lastSectionEnd = 0;
size_t alignedImageSize;
#ifdef _WIN64
POINTER_LIST* blockedMemory = NULL;
#endif

if (!CheckSize(size, sizeof(IMAGE_DOS_HEADER))) {
return NULL;
Expand Down Expand Up @@ -598,9 +625,41 @@ HMEMORYMODULE MemoryLoadLibraryEx(const void *data, size_t size,
}
}

#ifdef _WIN64
// check that memory-block does not span over the 4GB border
if ((unsigned long long)(code) / 0x100000000 < (unsigned long long)(code + alignedImageSize) / 0x100000000)
{
POINTER_LIST** current_node_ptr = &blockedMemory;

do
{
// store code to keep bad address blocked
*current_node_ptr = (POINTER_LIST*)malloc(sizeof(POINTER_LIST));
(*current_node_ptr)->next = NULL;
(*current_node_ptr)->address = code;
current_node_ptr = &(*current_node_ptr)->next;

code = (unsigned char *)allocMemory(NULL,
alignedImageSize,
MEM_RESERVE | MEM_COMMIT,
PAGE_READWRITE,
userdata);

if(code == NULL) {
FreePointerList(blockedMemory, freeMemory, userdata);
SetLastError(ERROR_OUTOFMEMORY);
return NULL;
}
} while((unsigned long long)(code) / 0x100000000 < (unsigned long long)(code + alignedImageSize) / 0x100000000);
}
#endif

result = (PMEMORYMODULE)HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, sizeof(MEMORYMODULE));
if (result == NULL) {
freeMemory(code, 0, MEM_RELEASE, userdata);
#ifdef _WIN64
FreePointerList(blockedMemory, freeMemory, userdata);
#endif
SetLastError(ERROR_OUTOFMEMORY);
return NULL;
}
Expand All @@ -614,6 +673,9 @@ HMEMORYMODULE MemoryLoadLibraryEx(const void *data, size_t size,
result->freeLibrary = freeLibrary;
result->userdata = userdata;
result->pageSize = sysInfo.dwPageSize;
#ifdef _WIN64
result->blockedMemory = blockedMemory;
#endif

if (!CheckSize(size, old_header->OptionalHeader.SizeOfHeaders)) {
goto error;
Expand Down Expand Up @@ -776,6 +838,11 @@ void MemoryFreeLibrary(HMEMORYMODULE mod)
module->free(module->codeBase, 0, MEM_RELEASE, module->userdata);
}

#ifdef _WIN64
// release blockeded memory
FreePointerList(module->blockedMemory, module->free, module->userdata);
#endif

HeapFree(GetProcessHeap(), 0, module);
}

Expand Down