private void FinalizeSections()
{
IMAGE_SECTION_HEADER *section = Win.IMAGE_FIRST_SECTION(_headers);
#if WIN64
UIntPtrT imageOffset = ((UIntPtrT)_headers->OptionalHeader.ImageBase & 0xffffffff00000000);
#elif WIN32
UIntPtrT imageOffset = 0;
#endif
SectionFinalizeData sectionData = new SectionFinalizeData();
sectionData.Address = (void *)(section->PhysicalAddress | imageOffset);
sectionData.AlignedAddress = AlignAddressDown(sectionData.Address, _pageSize);
sectionData.Size = GetRealSectionSize(section);
sectionData.Characteristics = section->Characteristics;
sectionData.Last = false;
section++;
// loop through all sections and change access flags
for (int i = 1; i < _headers->FileHeader.NumberOfSections; i++, section++)
{
void *sectionAddress = (void *)(section->PhysicalAddress | imageOffset);
void *alignedAddress = AlignAddressDown(sectionAddress, _pageSize);
SizeT sectionSize = GetRealSectionSize(section);
// Combine access flags of all sections that share a page
// TODO(fancycode): We currently share flags of a trailing large section
// with the page of a first small section. This should be optimized.
if (sectionData.AlignedAddress == alignedAddress || (UIntPtrT)sectionData.Address + sectionData.Size > (UIntPtrT)alignedAddress)
{
// Section shares page with previous
if ((section->Characteristics & Win.IMAGE_SCN_MEM_DISCARDABLE) == 0 || (sectionData.Characteristics & Win.IMAGE_SCN_MEM_DISCARDABLE) == 0)
{
sectionData.Characteristics = (sectionData.Characteristics | section->Characteristics) & ~Win.IMAGE_SCN_MEM_DISCARDABLE;
}
else
{
sectionData.Characteristics |= section->Characteristics;
}
sectionData.Size = (((UIntPtrT)sectionAddress) + (sectionSize)) - (UIntPtrT)sectionData.Address;
continue;
}
FinalizeSection(sectionData);
sectionData.Address = sectionAddress;
sectionData.AlignedAddress = alignedAddress;
sectionData.Size = sectionSize;
sectionData.Characteristics = section->Characteristics;
}
sectionData.Last = true;
FinalizeSection(sectionData);
}
static void FinalizeSections(ref IMAGE_NT_HEADERS OrgNTHeaders, IntPtr pCode, IntPtr pNTHeaders, uint PageSize)
{
UIntPtr imageOffset = (Is64BitProcess ? (UIntPtr)(unchecked ((ulong)pCode.ToInt64()) & 0xffffffff00000000) : UIntPtr.Zero);
IntPtr pSection = Win.IMAGE_FIRST_SECTION(pNTHeaders, OrgNTHeaders.FileHeader.SizeOfOptionalHeader);
IMAGE_SECTION_HEADER Section = PtrRead <IMAGE_SECTION_HEADER>(pSection);
SectionFinalizeData sectionData = new SectionFinalizeData();
sectionData.Address = PtrBitOr(PtrAdd((IntPtr)0, Section.PhysicalAddress), imageOffset);
sectionData.AlignedAddress = PtrAlignDown(sectionData.Address, (UIntPtr)PageSize);
sectionData.Size = GetRealSectionSize(ref Section, ref OrgNTHeaders);
sectionData.Characteristics = Section.Characteristics;
sectionData.Last = false;
pSection = PtrAdd(pSection, Sz.IMAGE_SECTION_HEADER);
// loop through all sections and change access flags
for (int i = 1; i < OrgNTHeaders.FileHeader.NumberOfSections; i++, pSection = PtrAdd(pSection, Sz.IMAGE_SECTION_HEADER))
{
Section = PtrRead <IMAGE_SECTION_HEADER>(pSection);
IntPtr sectionAddress = PtrBitOr(PtrAdd((IntPtr)0, Section.PhysicalAddress), imageOffset);
IntPtr alignedAddress = PtrAlignDown(sectionAddress, (UIntPtr)PageSize);
IntPtr sectionSize = GetRealSectionSize(ref Section, ref OrgNTHeaders);
// Combine access flags of all sections that share a page
// TODO(fancycode): We currently share flags of a trailing large section with the page of a first small section. This should be optimized.
IntPtr a = PtrAdd(sectionData.Address, sectionData.Size);
ulong b = unchecked ((ulong)a.ToInt64()), c = unchecked ((ulong)alignedAddress);
if (sectionData.AlignedAddress == alignedAddress || unchecked ((ulong)PtrAdd(sectionData.Address, sectionData.Size).ToInt64()) > unchecked ((ulong)alignedAddress))
{
// Section shares page with previous
if ((Section.Characteristics & Win.IMAGE_SCN_MEM_DISCARDABLE) == 0 || (sectionData.Characteristics & Win.IMAGE_SCN_MEM_DISCARDABLE) == 0)
{
sectionData.Characteristics = (sectionData.Characteristics | Section.Characteristics) & ~Win.IMAGE_SCN_MEM_DISCARDABLE;
}
else
{
sectionData.Characteristics |= Section.Characteristics;
}
sectionData.Size = PtrSub(PtrAdd(sectionAddress, sectionSize), sectionData.Address);
continue;
}
FinalizeSection(sectionData, PageSize, OrgNTHeaders.OptionalHeader.SectionAlignment);
sectionData.Address = sectionAddress;
sectionData.AlignedAddress = alignedAddress;
sectionData.Size = sectionSize;
sectionData.Characteristics = Section.Characteristics;
}
sectionData.Last = true;
FinalizeSection(sectionData, PageSize, OrgNTHeaders.OptionalHeader.SectionAlignment);
}
private void FinalizeSection(SectionFinalizeData sectionData)
{
uint protect, oldProtect;
int executable;
int readable;
int writeable;
if (sectionData.Size == 0)
{
return;
}
if ((sectionData.Characteristics & Win.IMAGE_SCN_MEM_DISCARDABLE) > 0)
{
// section is not needed any more and can safely be freed
if (sectionData.Address == sectionData.AlignedAddress &&
(sectionData.Last ||
_headers->OptionalHeader.SectionAlignment == _pageSize ||
(sectionData.Size % _pageSize) == 0)
)
{
// Only allowed to decommit whole pages
Win.VirtualFree(sectionData.Address, sectionData.Size, AllocationType.DECOMMIT);
}
return;
}
// determine protection flags based on characteristics
executable = (sectionData.Characteristics & (uint)ImageSectionFlags.IMAGE_SCN_MEM_EXECUTE) != 0 ? 1 : 0;
readable = (sectionData.Characteristics & (uint)ImageSectionFlags.IMAGE_SCN_MEM_READ) != 0 ? 1 : 0;
writeable = (sectionData.Characteristics & (uint)ImageSectionFlags.IMAGE_SCN_MEM_WRITE) != 0 ? 1 : 0;
protect = (uint)ProtectionFlags[executable, readable, writeable];
if ((sectionData.Characteristics & Win.IMAGE_SCN_MEM_NOT_CACHED) > 0)
{
protect |= Win.PAGE_NOCACHE;
}
// change memory access flags
if (!Win.VirtualProtect(sectionData.Address, sectionData.Size, protect, out oldProtect))
{
throw new NativeDllLoadException("Error protecting memory page");
}
}
static void FinalizeSection(SectionFinalizeData SectionData, uint PageSize, uint SectionAlignment)
{
if (SectionData.Size == IntPtr.Zero)
{
return;
}
if ((SectionData.Characteristics & Win.IMAGE_SCN_MEM_DISCARDABLE) > 0)
{
// section is not needed any more and can safely be freed
if (SectionData.Address == SectionData.AlignedAddress &&
(SectionData.Last ||
SectionAlignment == PageSize ||
(unchecked ((ulong)SectionData.Size.ToInt64()) % PageSize) == 0)
)
{
// Only allowed to decommit whole pages
Win.VirtualFree(SectionData.Address, SectionData.Size, AllocationType.DECOMMIT);
}
return;
}
// determine protection flags based on characteristics
int readable = (SectionData.Characteristics & (uint)ImageSectionFlags.IMAGE_SCN_MEM_READ) != 0 ? 1 : 0;
int writeable = (SectionData.Characteristics & (uint)ImageSectionFlags.IMAGE_SCN_MEM_WRITE) != 0 ? 1 : 0;
int executable = (SectionData.Characteristics & (uint)ImageSectionFlags.IMAGE_SCN_MEM_EXECUTE) != 0 ? 1 : 0;
uint protect = (uint)ProtectionFlags[executable, readable, writeable];
if ((SectionData.Characteristics & Win.IMAGE_SCN_MEM_NOT_CACHED) > 0)
{
protect |= Win.PAGE_NOCACHE;
}
// change memory access flags
uint oldProtect;
if (!Win.VirtualProtect(SectionData.Address, SectionData.Size, protect, out oldProtect))
{
throw new DllException("Error protecting memory page");
}
}