Intravision/reactos
1
0
Fork 0
mirror of https://github.com/reactos/reactos.git synced 2025-08-03 21:05:43 +00:00
Code Issues Projects Releases Packages Wiki Activity

[NTOS]: Add an extra layer of protection for freed nonpaged pool: write a 4-byte signature on freed blocks, and assert its valid on checked builds. Use a slightly less egocentric ASCII value than on Windows (name of the developer who wrote the first memory manager).

Browse source 
svn path=/trunk/; revision=48651
This commit is contained in:
Sir Richard 2010-08-29 19:32:25 +00:00
parent b85ab20f13
commit c574f50663
1 changed files with 6 additions and 0 deletions
Download patch file Download diff file Expand all files Collapse all files

6
reactos/ntoskrnl/mm/ARM3/pool.c
View file

@ -298,6 +298,7 @@ MiInitializeNonPagedPool(VOID)
FreeEntry = MmNonPagedPoolStart;
FirstEntry = FreeEntry;
FreeEntry->Size = PoolPages;
FreeEntry->Signature = MM_FREE_POOL_SIGNATURE;
FreeEntry->Owner = FirstEntry;
//
@ -316,6 +317,7 @@ MiInitializeNonPagedPool(VOID)
//
FreeEntry = (PMMFREE_POOL_ENTRY)((ULONG_PTR)FreeEntry + PAGE_SIZE);
FreeEntry->Owner = FirstEntry;
FreeEntry->Signature = MM_FREE_POOL_SIGNATURE;
}
//
@ -626,6 +628,7 @@ MiAllocatePoolPages(IN POOL_TYPE PoolType,
// Grab the entry and see if it can handle our allocation
//
FreeEntry = CONTAINING_RECORD(NextEntry, MMFREE_POOL_ENTRY, List);
ASSERT(FreeEntry->Signature == MM_FREE_POOL_SIGNATURE);
if (FreeEntry->Size >= SizeInPages)
{
//
@ -964,6 +967,7 @@ MiFreePoolPages(IN PVOID StartingVa)
//
FreeEntry = (PMMFREE_POOL_ENTRY)((ULONG_PTR)StartingVa +
(NumberOfPages << PAGE_SHIFT));
ASSERT(FreeEntry->Signature == MM_FREE_POOL_SIGNATURE);
ASSERT(FreeEntry->Owner == FreeEntry);
/* Consume this entry's pages */
@ -1032,6 +1036,7 @@ MiFreePoolPages(IN PVOID StartingVa)
// Get the free entry descriptor for that given page range
//
FreeEntry = (PMMFREE_POOL_ENTRY)((ULONG_PTR)StartingVa - PAGE_SIZE);
ASSERT(FreeEntry->Signature == MM_FREE_POOL_SIGNATURE);
FreeEntry = FreeEntry->Owner;
/* Check if protected pool is enabled */
@ -1118,6 +1123,7 @@ MiFreePoolPages(IN PVOID StartingVa)
// Link back to the parent free entry, and keep going
//
NextEntry->Owner = FreeEntry;
NextEntry->Signature = MM_FREE_POOL_SIGNATURE;
NextEntry = (PMMFREE_POOL_ENTRY)((ULONG_PTR)NextEntry + PAGE_SIZE);
} while (NextEntry != LastEntry);