BOOLEAN
KdbIsMemoryValid(PVOID pvBase, ULONG cjSize)
{
PUCHAR pjAddress;
pjAddress = ALIGN_DOWN_POINTER_BY(pvBase, PAGE_SIZE);
while (pjAddress < (PUCHAR)pvBase + cjSize)
{
if (!MmIsAddressValid(pjAddress)) return FALSE;
pjAddress += PAGE_SIZE;
}
return TRUE;
}
VOID
HeapRelease(
PVOID HeapHandle)
{
PHEAP Heap = HeapHandle;
PHEAP_BLOCK Block;
PUCHAR StartAddress, EndAddress;
PFN_COUNT FreePages, AllFreePages = 0;
TRACE("HeapRelease(%p)\n", HeapHandle);
/* Loop all heap chunks */
for (Block = &Heap->Blocks;
Block->Size != 0;
Block = Block + 1 + Block->Size)
{
/* Continue, if its not free */
if (Block->Tag != 0)
{
#ifdef FREELDR_HEAP_VERIFIER
/* Verify size and redzones */
ASSERT(*REDZONE_SIZE(Block) <= Block->Size * sizeof(HEAP_BLOCK));
ASSERT(*REDZONE_LOW(Block) == REDZONE_MARK);
ASSERT(*REDZONE_HI(Block) == REDZONE_MARK);
#endif
continue;
}
/* Calculate page aligned start address of the free region */
StartAddress = ALIGN_UP_POINTER_BY(Block->Data, PAGE_SIZE);
/* Walk over adjacent free blocks */
while (Block->Tag == 0) Block = Block + Block->Size + 1;
/* Check if this was the last block */
if (Block->Size == 0)
{
/* Align the end address up to cover the end of the heap */
EndAddress = ALIGN_UP_POINTER_BY(Block->Data, PAGE_SIZE);
}
else
{
/* Align the end address down to not cover any allocations */
EndAddress = ALIGN_DOWN_POINTER_BY(Block->Data, PAGE_SIZE);
}
/* Check if we have free pages */
if (EndAddress > StartAddress)
{
/* Calculate the size of the free region in pages */
FreePages = (PFN_COUNT)((EndAddress - StartAddress) / MM_PAGE_SIZE);
AllFreePages += FreePages;
/* Now mark the pages free */
MmMarkPagesInLookupTable(PageLookupTableAddress,
(ULONG_PTR)StartAddress / MM_PAGE_SIZE,
FreePages,
LoaderFree);
}
/* bail out, if it was the last block */
if (Block->Size == 0) break;
}
TRACE("HeapRelease() done, freed %ld pages\n", AllFreePages);
}
