[sir_richard] 45517: [FREELDR]: The hack to set pages from 0x100 to 0x1FF as busy so that the heap allocator wouldn't use them always restored the pages back to Free (since they usually were free on x86). However, if the pages were already being used in the first place, this made them appear free and corrupted existing memory. Fixed the hack so that it restores the previous state of the memory pages.

Author: sir_richard
Date: Tue Feb  9 03:22:08 2010
New Revision: 45517

URL: http://svn.reactos.org/svn/reactos?rev=45517&view=rev
Log:
[FREELDR]: The hack to set pages from 0x100 to 0x1FF as busy so that the heap allocator
wouldn't use them always restored the pages back to Free (since they usually were free
on x86). However, if the pages were already being used in the first place, this made them
appear free and corrupted existing memory. Fixed the hack so that it restores the previous
state of the memory pages.

Modified:
    trunk/reactos/boot/freeldr/freeldr/mm/meminit.c

Modified: trunk/reactos/boot/freeldr/freeldr/mm/meminit.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/boot/freeldr/freeldr/mm/me…
==============================================================================
--- trunk/reactos/boot/freeldr/freeldr/mm/meminit.c [iso-8859-1] (original)
+++ trunk/reactos/boot/freeldr/freeldr/mm/meminit.c [iso-8859-1] Tue Feb  9 03:22:08 2010
@@ -102,8 +102,11 @@
 {
 	ULONG PagesNeeded;
 	ULONG HeapStart;
-
+	MEMORY_TYPE Type;
+	PPAGE_LOOKUP_TABLE_ITEM RealPageLookupTable = (PPAGE_LOOKUP_TABLE_ITEM)PageLookupTable;
+	
 	// HACK: Make it so it doesn't overlap kernel space
+	Type = RealPageLookupTable[0x100].PageAllocated;
 	MmMarkPagesInLookupTable(PageLookupTableAddress, 0x100, 0xFF, LoaderSystemCode);
 
 	// Find contigious memory block for HEAP:STACK
@@ -111,7 +114,7 @@
 	HeapStart = MmFindAvailablePages(PageLookupTable, TotalPagesInLookupTable, PagesNeeded,
FALSE);
 
 	// Unapply the hack
-	MmMarkPagesInLookupTable(PageLookupTableAddress, 0x100, 0xFF, LoaderFree);
+	MmMarkPagesInLookupTable(PageLookupTableAddress, 0x100, 0xFF, Type);
 
 	if (HeapStart == 0)
 	{