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Set page protection for images having section alignment < page size

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svn path=/trunk/; revision=4110
This commit is contained in:
Gé van Geldorp 2003-02-03 11:52:46 +00:00
parent f5f297382d
commit 5bd96088c4
1 changed files with 55 additions and 9 deletions
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64
reactos/ntoskrnl/ldr/loader.c
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@ -1,4 +1,4 @@
/* $Id: loader.c,v 1.125 2002/11/05 21:01:38 hbirr Exp $
/* $Id: loader.c,v 1.126 2003/02/03 11:52:46 gvg Exp $
*
* COPYRIGHT: See COPYING in the top level directory
* PROJECT: ReactOS kernel
@ -811,6 +811,40 @@ LdrGetModuleObject(PUNICODE_STRING ModuleName)
/* ---------------------------------------------- PE Module support */
static BOOL
PageNeedsWriteAccess(PVOID PageStart,
PVOID DriverBase,
PIMAGE_FILE_HEADER PEFileHeader,
PIMAGE_SECTION_HEADER PESectionHeaders)
{
BOOL NeedsWriteAccess;
unsigned Idx;
ULONG Characteristics;
ULONG Length;
PVOID BaseAddress;
NeedsWriteAccess = FALSE;
/* Set the protections for the various parts of the driver */
for (Idx = 0; Idx < PEFileHeader->NumberOfSections && ! NeedsWriteAccess; Idx++)
{
Characteristics = PESectionHeaders[Idx].Characteristics;
if (!(Characteristics & IMAGE_SECTION_CHAR_CODE) ||
(Characteristics & IMAGE_SECTION_CHAR_WRITABLE ||
Characteristics & IMAGE_SECTION_CHAR_DATA ||
Characteristics & IMAGE_SECTION_CHAR_BSS))
{
Length =
max(PESectionHeaders[Idx].Misc.VirtualSize,
PESectionHeaders[Idx].SizeOfRawData);
BaseAddress = PESectionHeaders[Idx].VirtualAddress + DriverBase;
NeedsWriteAccess = BaseAddress < PageStart + PAGE_SIZE &&
PageStart < (PVOID)((PCHAR) BaseAddress + Length);
}
}
return(NeedsWriteAccess);
}
static NTSTATUS
LdrPEProcessModule(PVOID ModuleLoadBase,
PUNICODE_STRING FileName,
@ -1105,20 +1139,32 @@ LdrPEProcessModule(PVOID ModuleLoadBase,
ULONG Characteristics = PESectionHeaders[Idx].Characteristics;
ULONG Length;
PVOID BaseAddress;
ULONG i;
Length =
max(PESectionHeaders[Idx].Misc.VirtualSize,
PESectionHeaders[Idx].SizeOfRawData);
BaseAddress = PESectionHeaders[Idx].VirtualAddress + DriverBase;
PVOID PageAddress;
if (Characteristics & IMAGE_SECTION_CHAR_CODE &&
!(Characteristics & IMAGE_SECTION_CHAR_WRITABLE ||
Characteristics & IMAGE_SECTION_CHAR_DATA ||
Characteristics & IMAGE_SECTION_CHAR_BSS))
{
for (i = 0; i < PAGE_ROUND_UP(Length) / PAGE_SIZE; i++)
Length =
max(PESectionHeaders[Idx].Misc.VirtualSize,
PESectionHeaders[Idx].SizeOfRawData);
BaseAddress = PESectionHeaders[Idx].VirtualAddress + DriverBase;
PageAddress = (PVOID)PAGE_ROUND_DOWN(BaseAddress);
if (! PageNeedsWriteAccess(PageAddress, DriverBase, PEFileHeader, PESectionHeaders))
{
MmSetPageProtect(NULL, BaseAddress + (i * PAGE_SIZE),
PAGE_READONLY);
MmSetPageProtect(NULL, PageAddress, PAGE_READONLY);
}
PageAddress = (PVOID)((PCHAR) PageAddress + PAGE_SIZE);
while ((PVOID)((PCHAR) PageAddress + PAGE_SIZE) <
(PVOID)((PCHAR) BaseAddress + Length))
{
MmSetPageProtect(NULL, PageAddress, PAGE_READONLY);
PageAddress = (PVOID)((PCHAR) PageAddress + PAGE_SIZE);
}
if (PageAddress < (PVOID)((PCHAR) BaseAddress + Length) &&
! PageNeedsWriteAccess(PageAddress, DriverBase, PEFileHeader, PESectionHeaders))
{
MmSetPageProtect(NULL, PageAddress, PAGE_READONLY);
}
}
}