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fix memory-module crash with dll align with 512 #21

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progmboy wants to merge 3 commits into from
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fix memory-module crash with dll align with 512 #21

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7c85ec1
fix memory-module crash with dll align with 512
progmboy Dec 22, 2014
5a2100c
remove hardcode for PAGE_SIZE use GetNativeSystemInfo to get it
progmboy Dec 22, 2014
0875a2b
fix the problem when some sections in one page, the section's attribu…
progmboy Dec 22, 2014
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48 changes: 41 additions & 7 deletions MemoryModule.c
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Original file line number Diff line number Diff line change
Expand Up @@ -47,6 +47,8 @@
#define IMAGE_SIZEOF_BASE_RELOCATION (sizeof(IMAGE_BASE_RELOCATION))
#endif

#define ALIGN_DOWN_BY(length, alignment) ((ULONG_PTR)(length) & ~(alignment - 1))

#include "MemoryModule.h"

typedef BOOL (WINAPI *DllEntryProc)(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpReserved);
Expand Down Expand Up @@ -92,6 +94,9 @@ CopySections(const unsigned char *data, PIMAGE_NT_HEADERS old_headers, PMEMORYMO
unsigned char *codeBase = module->codeBase;
unsigned char *dest;
PIMAGE_SECTION_HEADER section = IMAGE_FIRST_SECTION(module->headers);
SYSTEM_INFO siSysInfo;
GetNativeSystemInfo(&siSysInfo);

for (i=0; i<module->headers->FileHeader.NumberOfSections; i++, section++) {
if (section->SizeOfRawData == 0) {
// section doesn't contain data in the dll itself, but may define
Expand All @@ -102,7 +107,9 @@ CopySections(const unsigned char *data, PIMAGE_NT_HEADERS old_headers, PMEMORYMO
size,
MEM_COMMIT,
PAGE_READWRITE);

if((POINTER_TYPE)(codeBase + section->VirtualAddress) % siSysInfo.dwPageSize){
dest = codeBase + section->VirtualAddress;
}
section->Misc.PhysicalAddress = (DWORD) (POINTER_TYPE) dest;
memset(dest, 0, size);
}
Expand All @@ -116,6 +123,9 @@ CopySections(const unsigned char *data, PIMAGE_NT_HEADERS old_headers, PMEMORYMO
section->SizeOfRawData,
MEM_COMMIT,
PAGE_READWRITE);
if((POINTER_TYPE)(codeBase + section->VirtualAddress) % siSysInfo.dwPageSize){
dest = codeBase + section->VirtualAddress;
}
memcpy(dest, data + section->PointerToRawData, section->SizeOfRawData);
section->Misc.PhysicalAddress = (DWORD) (POINTER_TYPE) dest;
}
Expand All @@ -139,28 +149,50 @@ FinalizeSections(PMEMORYMODULE module)
{
int i;
PIMAGE_SECTION_HEADER section = IMAGE_FIRST_SECTION(module->headers);
PIMAGE_SECTION_HEADER lastSection = NULL;
SYSTEM_INFO siSysInfo;
DWORD Characteristics;
#ifdef _WIN64
POINTER_TYPE imageOffset = (module->headers->OptionalHeader.ImageBase & 0xffffffff00000000);
#else
#define imageOffset 0
#endif

GetNativeSystemInfo(&siSysInfo);

// loop through all sections and change access flags
for (i=0; i<module->headers->FileHeader.NumberOfSections; i++, section++) {
DWORD protect, oldProtect, size;
int executable = (section->Characteristics & IMAGE_SCN_MEM_EXECUTE) != 0;
int readable = (section->Characteristics & IMAGE_SCN_MEM_READ) != 0;
int writeable = (section->Characteristics & IMAGE_SCN_MEM_WRITE) != 0;

if (section->Characteristics & IMAGE_SCN_MEM_DISCARDABLE) {
BOOL bInOnePage = FALSE;
int executable, readable, writeable;

if (lastSection != NULL){
if (ALIGN_DOWN_BY(lastSection->Misc.PhysicalAddress|imageOffset, siSysInfo.dwPageSize) ==
ALIGN_DOWN_BY(section->Misc.PhysicalAddress|imageOffset, siSysInfo.dwPageSize)){
//this section and last section are in same page
Characteristics |= lastSection->Characteristics;
bInOnePage = TRUE;
}else{
Characteristics = section->Characteristics;
}
}else{
Characteristics = section->Characteristics;
}

executable = (Characteristics & IMAGE_SCN_MEM_EXECUTE) != 0;
readable = (Characteristics & IMAGE_SCN_MEM_READ) != 0;
writeable = (Characteristics & IMAGE_SCN_MEM_WRITE) != 0;

if (Characteristics & IMAGE_SCN_MEM_DISCARDABLE && !bInOnePage) {
// section is not needed any more and can safely be freed
VirtualFree((LPVOID)((POINTER_TYPE)section->Misc.PhysicalAddress | imageOffset), section->SizeOfRawData, MEM_DECOMMIT);
lastSection = section;
continue;
}

// determine protection flags based on characteristics
protect = ProtectionFlags[executable][readable][writeable];
if (section->Characteristics & IMAGE_SCN_MEM_NOT_CACHED) {
if (Characteristics & IMAGE_SCN_MEM_NOT_CACHED) {
protect |= PAGE_NOCACHE;
}

Expand All @@ -174,6 +206,8 @@ FinalizeSections(PMEMORYMODULE module)
}
}

lastSection = section;

if (size > 0) {
// change memory access flags
if (VirtualProtect((LPVOID)((POINTER_TYPE)section->Misc.PhysicalAddress | imageOffset), size, protect, &oldProtect) == 0)
Expand Down