heapalloc.c File Reference

#include "bl.h"

Include dependency graph for heapalloc.c:

Go to the source code of this file.

Classes
struct	_BL_HEAP_POINTER
struct	_BL_FREE_HEAP_ENTRY
struct	_BL_BUSY_HEAP_ENTRY
struct	_BL_HEAP_BOUNDARIES

Macros
#define	BL_HEAP_POINTER_FLAG_BITS   3

Typedefs
typedef struct _BL_HEAP_POINTER	BL_HEAP_POINTER
typedef struct _BL_HEAP_POINTER *	PBL_HEAP_POINTER
typedef struct _BL_FREE_HEAP_ENTRY	BL_FREE_HEAP_ENTRY
typedef struct _BL_FREE_HEAP_ENTRY *	PBL_FREE_HEAP_ENTRY
typedef struct _BL_BUSY_HEAP_ENTRY	BL_BUSY_HEAP_ENTRY
typedef struct _BL_BUSY_HEAP_ENTRY *	PBL_BUSY_HEAP_ENTRY
typedef struct _BL_HEAP_BOUNDARIES	BL_HEAP_BOUNDARIES
typedef struct _BL_HEAP_BOUNDARIES *	PBL_HEAP_BOUNDARIES

Functions
FORCEINLINE PBL_FREE_HEAP_ENTRY	MmHapDecodeLink (_In_ BL_HEAP_POINTER Link)
FORCEINLINE ULONG	MmHapBufferSize (_In_ PVOID FreeEntry)
FORCEINLINE ULONG	MmHapUserBufferSize (_In_ PVOID FreeEntry)
NTSTATUS	MmHapHeapAllocatorExtend (_In_ ULONG ExtendSize)
ULONG	MmHapGetBucketId (_In_ ULONG Size)
VOID	MmHapReportHeapCorruption (_In_ PBL_FREE_HEAP_ENTRY BufferEntry)
PVOID	MmHapCheckFreeLinks (_In_ PVOID BufferEntry)
PVOID	MmHapCheckBufferLinks (_In_ PVOID BufferEntry)
PBL_FREE_HEAP_ENTRY	MmHapRemoveBufferFromFreeList (_In_ PBL_FREE_HEAP_ENTRY FreeEntry)
PBL_FREE_HEAP_ENTRY	MmHapCoalesceFreeBuffer (_In_ PBL_FREE_HEAP_ENTRY FreeEntry)
PBL_FREE_HEAP_ENTRY	MmHapAddToFreeList (_In_ PBL_BUSY_HEAP_ENTRY Entry, _In_ ULONG Flags)
PBL_BUSY_HEAP_ENTRY	MmHapFindBufferInFreeList (_In_ ULONG Size)
NTSTATUS	MmHaInitialize (_In_ ULONG HeapSize, _In_ ULONG HeapAttributes)
PVOID	BlMmAllocateHeap (_In_ SIZE_T Size)
NTSTATUS	BlMmFreeHeap (_In_ PVOID Buffer)

Variables
ULONG	HapInitializationStatus
LIST_ENTRY	MmHeapBoundaries
ULONG	HapMinimumHeapSize
ULONG	HapAllocationAttributes
PBL_FREE_HEAP_ENTRY *	MmFreeList

Macro Definition Documentation

BL_HEAP_POINTER_FLAG_BITS

#define BL_HEAP_POINTER_FLAG_BITS   3

Definition at line 15 of file heapalloc.c.

Typedef Documentation

BL_BUSY_HEAP_ENTRY

typedef struct _BL_BUSY_HEAP_ENTRY BL_BUSY_HEAP_ENTRY

BL_FREE_HEAP_ENTRY

typedef struct _BL_FREE_HEAP_ENTRY BL_FREE_HEAP_ENTRY

BL_HEAP_BOUNDARIES

typedef struct _BL_HEAP_BOUNDARIES BL_HEAP_BOUNDARIES

BL_HEAP_POINTER

typedef struct _BL_HEAP_POINTER BL_HEAP_POINTER

PBL_BUSY_HEAP_ENTRY

typedef struct _BL_BUSY_HEAP_ENTRY * PBL_BUSY_HEAP_ENTRY

PBL_FREE_HEAP_ENTRY

typedef struct _BL_FREE_HEAP_ENTRY * PBL_FREE_HEAP_ENTRY

PBL_HEAP_BOUNDARIES

typedef struct _BL_HEAP_BOUNDARIES * PBL_HEAP_BOUNDARIES

PBL_HEAP_POINTER

typedef struct _BL_HEAP_POINTER * PBL_HEAP_POINTER

Function Documentation

BlMmAllocateHeap()

PVOID BlMmAllocateHeap

(

_In_ SIZE_T

Size

)

Definition at line 569 of file heapalloc.c.

{
    ULONG BufferSize;
    PBL_HEAP_BOUNDARIES Heap;
    PBL_BUSY_HEAP_ENTRY BusyEntry, FreeEntry, NextEntry;
 
    /* Ignore heap allocation if the heap allocator isn't ready yet */
    if (HapInitializationStatus != 1)
    {
        return NULL;
    }
 
    /* Align the buffer size to the minimum size required */
    BufferSize = ALIGN_UP_BY(Size + FIELD_OFFSET(BL_BUSY_HEAP_ENTRY, Buffer),
                             FIELD_OFFSET(BL_BUSY_HEAP_ENTRY, Buffer));
 
    /* Watch out for overflow */
    if (BufferSize <= Size)
    {
        return NULL;
    }
 
    /* Make sure it's at least big enough to hold a free entry later on */
    if (BufferSize < sizeof(BL_FREE_HEAP_ENTRY))
    {
        BufferSize = sizeof(BL_FREE_HEAP_ENTRY);
    }
 
    /* Loop while we try to allocate memory */
    while (1)
    {
        /* Find a free buffer for this allocation */
        BusyEntry = MmHapFindBufferInFreeList(BufferSize);
        if (BusyEntry)
        {
            break;
        }
 
        /* We couldn't find a free buffer. Do we have any heaps? */
        if (!IsListEmpty(&MmHeapBoundaries))
        {
            /* Get the current heap */
            Heap = CONTAINING_RECORD(MmHeapBoundaries.Flink,
                                     BL_HEAP_BOUNDARIES,
                                     ListEntry);
 
            /* Check if we have space in the heap page for this allocation? */
            FreeEntry = Heap->HeapStart;
            NextEntry = (PBL_BUSY_HEAP_ENTRY)((ULONG_PTR)FreeEntry + BufferSize);
 
            if ((NextEntry >= FreeEntry) &&
                ((ULONG_PTR)NextEntry <=
                 Heap->HeapLimit - FIELD_OFFSET(BL_BUSY_HEAP_ENTRY, Buffer)))
            {
                /* Update the heap top pointer past this allocation */
                Heap->HeapStart = NextEntry;
 
                /* Make this allocation point to the slot */
                FreeEntry->BufferNext.P = Heap->HeapStart;
 
                /* And make the free heap entry point back to us */
                Heap->HeapStart->BufferPrevious.P = FreeEntry;
 
                /* Mark the heap entry as being free and on the heap */
                Heap->HeapStart->BufferNext.BufferFree = 1;
                Heap->HeapStart->BufferNext.BufferOnHeap = 1;
 
                /* The previously freed entry on the heap page is now ours */
                BusyEntry = FreeEntry;
                break;
            }
        }
 
        /* We have no heaps or space on any heap -- extend the heap and retry */
        if (!NT_SUCCESS(MmHapHeapAllocatorExtend(BufferSize)))
        {
            EfiPrintf(L"Heap extension failed!\r\n");
            return NULL;
        }
 
        EfiPrintf(L"Heap extended -- trying again\r\n");
    }
 
    /* Clear all the bits, marking this entry as allocated */
    BusyEntry->BufferNext.P = MmHapDecodeLink(BusyEntry->BufferNext);
 
    /* Return the entry's data buffer */
    //EfiPrintf(L"Returning buffer at 0x%p\r\n", &BusyEntry->Buffer);
    return &BusyEntry->Buffer;
}

Referenced by BcdEnumerateAndUnpackElements(), BcdOpenStoreFromFile(), BfLoadFontFile(), BiEnumerateElements(), BiEnumerateSubKeys(), BiGetRegistryValue(), BiLoadHive(), BiOpenKey(), BlAppendBootOptionBoolean(), BlAppendBootOptionInteger(), BlAppendBootOptions(), BlAppendBootOptionString(), BlCopyBootOptions(), BlGetBootOptionDevice(), BlGetBootOptionGuidList(), BlGetBootOptionString(), BlHtCreate(), BlHtStore(), BlImgLoadBootApplication(), BlMmGetMemoryMap(), BlockIoEfiCreateDeviceEntry(), BlockIoOpen(), BlockIopInitialize(), BlpDeviceInitialize(), BlpDeviceOpen(), BlpFileInitialize(), BlpFileRegisterFileSystem(), BlpGetBootOptionIntegerList(), BlpIoInitialize(), BlpMmCreateBlockAllocator(), BlReplaceBootOptions(), BlTblSetEntry(), BmEnumerateBootEntries(), BmFwInitializeBootDirectoryPath(), BmGetBootSequence(), BmGetOptionList(), BmOpenDataStore(), BmpFwGetApplicationDirectoryPath(), BmpFwGetFullPath(), BmpGetSelectedBootEntry(), BmpPopulateBootEntryList(), CmpAllocate(), ConsoleCreateLocalInputConsole(), ConsoleCreateRemoteConsole(), ConsoleEfiTextFindModeFromAllowed(), ConsoleInputBaseConstruct(), ConsolepClearBuffer(), ConvertBmpToGopBlt(), DsppInitialize(), DsppLoadFontFile(), EfiLocateHandleBuffer(), EfiVmOpenProtocol(), EtfsInitialize(), EtfsMount(), EtfsOpen(), EtfspCreateContext(), FatInitialize(), FileIoCopyFileName(), FileIoCopyParentDirectoryPath(), ImgpInitializeBootApplicationParameters(), MmBaInitialize(), MmMdFreeGlobalDescriptors(), OslPrepareTarget(), and RtlpAllocateMemory().

BlMmFreeHeap()

NTSTATUS BlMmFreeHeap

(

_In_ PVOID

Buffer

)

Definition at line 663 of file heapalloc.c.

{
    PBL_BUSY_HEAP_ENTRY BusyEntry;
    PBL_HEAP_BOUNDARIES Heap;
    PLIST_ENTRY NextEntry;
 
    /* If the heap is not initialized, fail */
    if (HapInitializationStatus != 1)
    {
        return STATUS_UNSUCCESSFUL;
    }
 
    /* Get the heap header */
    //EfiPrintf(L"Freeing entry at: %p\r\n", Buffer);
    if (Buffer)
    {
        /* Don't free heap until we discover the corruption */
        return STATUS_SUCCESS;
    }
 
    BusyEntry = CONTAINING_RECORD(Buffer, BL_BUSY_HEAP_ENTRY, Buffer);
 
    /* Loop all the heaps */
    NextEntry = MmHeapBoundaries.Flink;
    while (NextEntry != &MmHeapBoundaries)
    {
        /* Get the current heap in the list */
        Heap = CONTAINING_RECORD(NextEntry, BL_HEAP_BOUNDARIES, ListEntry);
 
        /* Is this entry part of this heap? */
        if (((ULONG_PTR)Heap->HeapBase <= (ULONG_PTR)BusyEntry) &&
            ((ULONG_PTR)BusyEntry < (ULONG_PTR)Heap->HeapStart))
        {
            /* Ignore double-free */
            if (BusyEntry->BufferNext.BufferFree)
            {
                return STATUS_INVALID_PARAMETER;
            }
 
            /* It is -- add it to the free list */
            MmHapAddToFreeList(BusyEntry, 0);
            return STATUS_SUCCESS;
        }
 
        /* It isn't, move to the next heap */
        NextEntry = NextEntry->Flink;
    }
 
    /* The entry is not on any valid heap */
    return STATUS_INVALID_PARAMETER;
}

Referenced by BcdEnumerateAndUnpackElements(), BcdOpenStoreFromFile(), BfiFreeDeferredFontFile(), BiCloseKey(), BiDeleteKey(), BiEnumerateElements(), BiEnumerateSubKeys(), BiGetObjectDescription(), BiLoadHive(), BiOpenKey(), BlAppendBootOptionBoolean(), BlAppendBootOptionInteger(), BlAppendBootOptions(), BlAppendBootOptionString(), BlDestroyBootEntry(), BlFwEnumerateDevice(), BlGetBootOptionDevice(), BlHtCreate(), BlHtDelete(), BlImgLoadBootApplication(), BlImgUnloadBootApplication(), BlMmGetMemoryMap(), BlockIoDeviceTableDestroy(), BlockIoDeviceTableDestroyEntry(), BlockIoEfiCompareDevice(), BlockIoEfiCreateDeviceEntry(), BlockIoEfiGetChildHandle(), BlockIoFirmwareOpen(), BlockIopDestroy(), BlockIopFreeAllocations(), BlpDeviceOpen(), BlpFileRegisterFileSystem(), BlpMmCreateBlockAllocator(), BlpResourceInitialize(), BlReplaceBootOptions(), BlTblSetEntry(), BmEnumerateBootEntries(), BmErrorPurge(), BmFwInitializeBootDirectoryPath(), BmGetBootSequence(), BmGetOptionList(), BmLaunchRecoverySequence(), BmMain(), BmOpenDataStore(), BmpFwGetApplicationDirectoryPath(), BmpGetSelectedBootEntry(), BmpInitializeBootStatusDataLog(), BmpPopulateBootEntryList(), BmpTransferExecution(), BmpUpdateApplicationOptions(), CmpFree(), ConsoleCreateLocalInputConsole(), ConsoleCreateRemoteConsole(), ConsoleEfiTextFindModeFromAllowed(), ConsoleInputLocalDestruct(), DeviceTableDestroyEntry(), DsppInitialize(), DsppLoadFontFile(), EfiLocateHandleBuffer(), EfiVmOpenProtocol(), EfiVmpFreeInterfaceEntry(), EtfsMount(), EtfsOpen(), EtfspDeviceContextDestroy(), FileIoCopyParentDirectoryPath(), FileIoOpen(), FileTableDestroyEntry(), ImgpInitializeBootApplicationParameters(), MmBapFreeBlockAllocatorTableEntry(), MmMdFreeDescriptor(), OslpRemoveInternalApplicationOptions(), OslPrepareTarget(), and RtlpFreeMemory().

MmHaInitialize()

NTSTATUS MmHaInitialize	(	_In_ ULONG	HeapSize,
		_In_ ULONG	HeapAttributes
	)

Definition at line 538 of file heapalloc.c.

{
    NTSTATUS Status;
 
    /* No free list to begin with */
    MmFreeList = NULL;
 
    /* Configure the minimum heap size and allocation attributes */
    HapMinimumHeapSize = ALIGN_UP_BY(HeapSize, PAGE_SIZE);
    HapAllocationAttributes = HeapAttributes & 0x20000;
 
    /* Initialize the heap boundary list */
    InitializeListHead(&MmHeapBoundaries);
 
    /* Initialize a heap big enough to handle a one pointer long allocation */
    Status = MmHapHeapAllocatorExtend(sizeof(PVOID));
    if (NT_SUCCESS(Status))
    {
        /* The heap is ready! */
        HapInitializationStatus = 1;
        Status = STATUS_SUCCESS;
    }
 
    /* Return initialization status */
    return Status;
}

Referenced by BlpMmInitialize().

MmHapAddToFreeList()

PBL_FREE_HEAP_ENTRY MmHapAddToFreeList	(	_In_ PBL_BUSY_HEAP_ENTRY	Entry,
		_In_ ULONG	Flags
	)

Definition at line 393 of file heapalloc.c.

{
    PBL_FREE_HEAP_ENTRY FreeEntry, Head;
    ULONG BucketId;
    BL_LIBRARY_PARAMETERS LocalParameters;
 
    /* First, check if the entry is valid */
    Entry = MmHapCheckBufferLinks(Entry);
    if (!Entry)
    {
        return NULL;
    }
 
    /* Check if we should zero the entry */
    LocalParameters = BlpLibraryParameters;
    if ((LocalParameters.LibraryFlags & BL_LIBRARY_FLAG_ZERO_HEAP_ALLOCATIONS_ON_FREE) &&
        !(Flags))
    {
        /* Yep, zero it out */
        RtlZeroMemory(Entry->Buffer, MmHapUserBufferSize(Entry));
    }
 
    /* Now mark the entry as free */
    Entry->BufferNext.BufferFree = 1;
 
    /* Now that this buffer is free, try to coalesce it */
    FreeEntry = MmHapCoalesceFreeBuffer((PBL_FREE_HEAP_ENTRY)Entry);
    if (!FreeEntry)
    {
        return FreeEntry;
    }
 
    /* Compute the bucket ID for the free list */
    BucketId = MmHapGetBucketId(MmHapBufferSize(Entry));
 
    /* Get the current head for this bucket, if one exists */
    Head = MmFreeList ? MmFreeList[BucketId] : NULL;
 
    /* Update the head's backlink to point to this newly freed entry */
    if (Head)
    {
        Head->FreePrevious.P = FreeEntry;
    }
 
    /* Nobody behind us, the old head in front of us */
    FreeEntry->FreePrevious.P = NULL;
    FreeEntry->FreeNext.P = Head;
 
    /* Put us at the head of list now, and return the entry */
    MmFreeList[BucketId] = FreeEntry;
    return FreeEntry;
}

Referenced by BlMmFreeHeap(), and MmHapFindBufferInFreeList().

MmHapBufferSize()

FORCEINLINE ULONG MmHapBufferSize

(

_In_ PVOID

FreeEntry

)

Definition at line 76 of file heapalloc.c.

{
    PBL_FREE_HEAP_ENTRY Entry = FreeEntry;
 
    /* The space between the next buffer header and this one is the size */
    return (ULONG_PTR)MmHapDecodeLink(Entry->BufferNext) - (ULONG_PTR)Entry;
}

Referenced by MmHapAddToFreeList(), MmHapFindBufferInFreeList(), MmHapRemoveBufferFromFreeList(), and MmHapUserBufferSize().

MmHapCheckBufferLinks()

PVOID MmHapCheckBufferLinks

(

_In_ PVOID

BufferEntry

)

Definition at line 268 of file heapalloc.c.

{
    PBL_FREE_HEAP_ENTRY Prev, Next;
    PBL_FREE_HEAP_ENTRY Entry = BufferEntry;
 
    /* Get the previous and next buffer pointers */
    Prev = MmHapDecodeLink(Entry->BufferPrevious);
    Next = MmHapDecodeLink(Entry->BufferNext);
 
    /* Make sure that both the previous and next entries point to this one */
    if (((Next) && (MmHapDecodeLink(Next->BufferPrevious)) != Entry) ||
        ((Prev) && (MmHapDecodeLink(Prev->BufferNext)) != Entry))
    {
        /* They don't, so the heap headers are corrupted */
        MmHapReportHeapCorruption(Entry);
        return NULL;
    }
 
    /* They, do the entry is valid */
    return Entry;
}

Referenced by MmHapAddToFreeList(), MmHapCoalesceFreeBuffer(), and MmHapFindBufferInFreeList().

MmHapCheckFreeLinks()

PVOID MmHapCheckFreeLinks

(

_In_ PVOID

BufferEntry

)

Definition at line 243 of file heapalloc.c.

{
    PBL_FREE_HEAP_ENTRY Prev, Next;
    PBL_FREE_HEAP_ENTRY Entry = BufferEntry;
 
    /* Get the previous and next free pointers */
    Prev = MmHapDecodeLink(Entry->FreePrevious);
    Next = MmHapDecodeLink(Entry->FreeNext);
 
    /* Make sure that both the previous and next entries point to this one */
    if (((Next) && (MmHapDecodeLink(Next->FreePrevious)) != Entry) ||
        ((Prev) && (MmHapDecodeLink(Prev->FreeNext)) != Entry))
    {
        /* They don't, so the free headers are corrupted */
        MmHapReportHeapCorruption(Entry);
        return NULL;
    }
 
    /* They do, return the free entry as valid */
    return Entry;
}

Referenced by MmHapRemoveBufferFromFreeList().

MmHapCoalesceFreeBuffer()

PBL_FREE_HEAP_ENTRY MmHapCoalesceFreeBuffer

(

_In_ PBL_FREE_HEAP_ENTRY

FreeEntry

)

Definition at line 333 of file heapalloc.c.

{
    PBL_FREE_HEAP_ENTRY Prev, Next;
 
    /* First make sure that this is a valid buffer entry */
    if (!MmHapCheckBufferLinks(FreeEntry))
    {
        return NULL;
    }
 
    /* Get the next entry and check if it's free */
    Next = MmHapDecodeLink(FreeEntry->BufferNext);
    if (!(Next->BufferNext.BufferOnHeap) && (Next->BufferNext.BufferFree))
    {
        /* Remove the next buffer from the free list since we're coalescing */
        Next = MmHapRemoveBufferFromFreeList(Next);
        if (!Next)
        {
            return NULL;
        }
 
        /* The forward link of the *new* free buffer should now point to us */
        MmHapDecodeLink(Next->BufferNext)->BufferPrevious.P = FreeEntry;
 
        /* Our forward link should point to the *new* free buffer as well */
        FreeEntry->BufferNext.P = MmHapDecodeLink(Next->BufferNext);
 
        /* Mark our buffer as free */
        FreeEntry->BufferNext.BufferFree = 1;
    }
 
    /* Get the previous entry and check if it's free */
    Prev = MmHapDecodeLink(FreeEntry->BufferPrevious);
    if (!(Prev) || !(Prev->BufferNext.BufferFree))
    {
        return FreeEntry;
    }
 
    /* It's free, so remove it */
    Prev = MmHapRemoveBufferFromFreeList(Prev);
    if (!Prev)
    {
        return NULL;
    }
 
    /* The previous link of our next buffer should now point to our *previous* */
    MmHapDecodeLink(FreeEntry->BufferNext)->BufferPrevious.P = Prev;
 
    /* Our previous link should point the next free buffer now */
    Prev->BufferNext.P = MmHapDecodeLink(FreeEntry->BufferNext);
 
    /* Set the new freed buffer as the previous buffer, and mark it free */
    FreeEntry = Prev;
    FreeEntry->BufferNext.BufferFree = 1;
    return FreeEntry;
}

Referenced by MmHapAddToFreeList().

MmHapDecodeLink()

FORCEINLINE PBL_FREE_HEAP_ENTRY MmHapDecodeLink

(

_In_ BL_HEAP_POINTER

Link

)

Definition at line 66 of file heapalloc.c.

{
    /* Decode the buffer pointer by ignoring the flags */
    return (PBL_FREE_HEAP_ENTRY)(Link.BufferPointer << BL_HEAP_POINTER_FLAG_BITS);
}

Referenced by BlMmAllocateHeap(), MmHapBufferSize(), MmHapCheckBufferLinks(), MmHapCheckFreeLinks(), MmHapCoalesceFreeBuffer(), MmHapFindBufferInFreeList(), and MmHapRemoveBufferFromFreeList().

MmHapFindBufferInFreeList()

PBL_BUSY_HEAP_ENTRY MmHapFindBufferInFreeList

(

_In_ ULONG

Size

)

Definition at line 450 of file heapalloc.c.

{
    PBL_FREE_HEAP_ENTRY FreeEntry = NULL;
    PBL_BUSY_HEAP_ENTRY NextEntry;
    ULONG BucketId;
 
    /* Get the appropriate bucket for our size */
    BucketId = MmHapGetBucketId(Size);
    if (BucketId >= 8)
    {
        return NULL;
    }
 
    /* Keep going as long as we don't have a free entry */
    while (!FreeEntry)
    {
        /* Fet the first free entry in this list */
        FreeEntry = MmFreeList ? MmFreeList[BucketId] : NULL;
 
        /* Loop as long as there's entries in the list */
        while (FreeEntry)
        {
            /* Can this free entry satisfy our needs? */
            if (MmHapBufferSize(FreeEntry) >= Size)
            {
                /* All good */
                break;
            }
 
            /* It cannot, keep going to the next one */
            FreeEntry = MmHapDecodeLink(FreeEntry->FreeNext);
        }
 
        /* Try the next list -- have we exhausted all the lists? */
        if (++BucketId >= 8)
        {
            /* Have we not found an entry yet? Fail if so... */
            if (!FreeEntry)
            {
                return NULL;
            }
        }
    }
 
    /* We should have an entry if we're here. Remove it from the free list */
    NT_ASSERT(FreeEntry != NULL);
    FreeEntry = MmHapRemoveBufferFromFreeList(FreeEntry);
    if (!FreeEntry)
    {
        return NULL;
    }
 
    /* Make sure it's not corrupted */
    FreeEntry = MmHapCheckBufferLinks(FreeEntry);
    if (!FreeEntry)
    {
        return NULL;
    }
 
    /* Do we have space for at least another buffer? */
    if ((MmHapBufferSize(FreeEntry) - Size) >= sizeof(BL_FREE_HEAP_ENTRY))
    {
        /* Go to where the new next buffer will  start */
        NextEntry = (PBL_BUSY_HEAP_ENTRY)((ULONG_PTR)FreeEntry + Size);
 
        /* Make the new next buffer point to the next buffer */
        NextEntry->BufferNext.P = MmHapDecodeLink(FreeEntry->BufferNext);
 
        /* Make the old next buffer point back to the new one */
        MmHapDecodeLink(FreeEntry->BufferNext)->BufferPrevious.P = NextEntry;
 
        /* Point the new next buffer point back to us */
        NextEntry->BufferPrevious.P = FreeEntry;
 
        /* Point us to the new next buffer */
        FreeEntry->BufferNext.P = NextEntry;
 
        /* And insert the new next buffer into the free list */
        MmHapAddToFreeList(NextEntry, 1);
    }
 
    /* Return the entry, which is now allocated */
    return (PBL_BUSY_HEAP_ENTRY)FreeEntry;
}

Referenced by BlMmAllocateHeap().

MmHapGetBucketId()

ULONG MmHapGetBucketId

(

_In_ ULONG

Size

)

Definition at line 199 of file heapalloc.c.

{
    ULONG BucketIndex = 0;
 
    /* Use the last bucket if this is a large allocation */
    if (Size >= PAGE_SIZE)
    {
        return 7;
    }
 
    /* Otherwise, use a higher index for each new power of two */
    while (Size >> BucketIndex)
    {
        BucketIndex++;
    }
 
    /* Allocations are at least 16 bytes (2^4 = 5th index) */
    return BucketIndex - 5;
}

Referenced by MmHapAddToFreeList(), MmHapFindBufferInFreeList(), and MmHapRemoveBufferFromFreeList().

MmHapHeapAllocatorExtend()

NTSTATUS MmHapHeapAllocatorExtend

(

_In_ ULONG

ExtendSize

)

Definition at line 102 of file heapalloc.c.

{
    ULONG HeapSize, AlignedSize, HeapLimit;
    PBL_HEAP_BOUNDARIES Heap, NewHeap;
    NTSTATUS Status;
    PBL_BUSY_HEAP_ENTRY HeapBase = NULL;
 
    /* Compute a new heap, and add 2 more pages for the free list */
    HeapSize = ExtendSize + (2 * PAGE_SIZE);
    if (HeapSize < ExtendSize)
    {
        return STATUS_INTEGER_OVERFLOW;
    }
 
    /* Make sure the new heap is at least the minimum configured size */
    if (HapMinimumHeapSize > HeapSize)
    {
        HeapSize = HapMinimumHeapSize;
    }
 
    /* Align it on a page boundary */
    AlignedSize = ALIGN_UP_BY(HeapSize, PAGE_SIZE);
    if (!AlignedSize)
    {
        return STATUS_INTEGER_OVERFLOW;
    }
 
    /* Check if we already have a heap */
    if (!IsListEmpty(&MmHeapBoundaries))
    {
        /* Find the first heap*/
        Heap = CONTAINING_RECORD(MmHeapBoundaries.Flink,
                                 BL_HEAP_BOUNDARIES,
                                 ListEntry);
 
        /* Check if we have a page free above the heap */
        HeapLimit = Heap->HeapLimit + PAGE_SIZE;
        if (HeapLimit <= Heap->HeapEnd)
        {
            EfiPrintf(L"Heap extension TODO\r\n");
            return STATUS_INSUFFICIENT_RESOURCES;
        }
    }
 
    /* We do not -- allocate one */
    Status = MmPapAllocatePagesInRange((PVOID*)&HeapBase,
                                       BlLoaderHeap,
                                       AlignedSize >> PAGE_SHIFT,
                                       HapAllocationAttributes,
                                       0,
                                       NULL,
                                       0);
    if (!NT_SUCCESS(Status))
    {
        EfiPrintf(L"HEAP ALLOCATION FAILED\r\n");
        EfiStall(1000000);
        return Status;
    }
 
    /* Set the heap bottom, limit, and top */
    NewHeap = (PBL_HEAP_BOUNDARIES)HeapBase->Buffer;
    NewHeap->HeapBase = (ULONG_PTR)HeapBase;
    NewHeap->HeapLimit = (ULONG_PTR)HeapBase + AlignedSize;
    NewHeap->HeapStart = (PBL_BUSY_HEAP_ENTRY)(NewHeap + 1);
 
    /* Set the buffer links */
    HeapBase->BufferPrevious.P = NULL;
    HeapBase->BufferNext.P = NewHeap->HeapStart;
 
    /* Set the buffer at the top of the heap and mark it as being free */
    NewHeap->HeapStart->BufferPrevious.P = HeapBase;
    NewHeap->HeapStart->BufferNext.P =  NewHeap->HeapStart;
    NewHeap->HeapStart->BufferNext.BufferFree = 1;
    NewHeap->HeapStart->BufferNext.BufferOnHeap = 1;
 
    /* Is this the first heap ever? */
    if (IsListEmpty(&MmHeapBoundaries))
    {
        /* We will host the free list at the top of the heap */
        MmFreeList = (PBL_FREE_HEAP_ENTRY*)((ULONG_PTR)NewHeap->HeapLimit - 8 * sizeof(PBL_FREE_HEAP_ENTRY));
        NewHeap->HeapLimit = (ULONG_PTR)MmFreeList;
        RtlZeroMemory(MmFreeList, 8 * sizeof(PBL_FREE_HEAP_ENTRY));
    }
 
    /* Remove a page on top */
    HeapLimit = NewHeap->HeapLimit;
    NewHeap->HeapEnd = NewHeap->HeapLimit;
    NewHeap->HeapLimit -= PAGE_SIZE;
 
    /* Add us into the heap list */
    InsertTailList(&MmHeapBoundaries, &NewHeap->ListEntry);
    return STATUS_SUCCESS;
}

Referenced by BlMmAllocateHeap(), and MmHaInitialize().

MmHapRemoveBufferFromFreeList()

PBL_FREE_HEAP_ENTRY MmHapRemoveBufferFromFreeList

(

_In_ PBL_FREE_HEAP_ENTRY

FreeEntry

)

Definition at line 293 of file heapalloc.c.

{
    PBL_FREE_HEAP_ENTRY Prev, Next;
 
    /* Firest, make sure the free entry is valid */
    FreeEntry = MmHapCheckFreeLinks(FreeEntry);
    if (!FreeEntry)
    {
        return FreeEntry;
    }
 
    /* Get the previous and next entry */
    Prev = MmHapDecodeLink(FreeEntry->FreePrevious);
    Next = MmHapDecodeLink(FreeEntry->FreeNext);
 
    /* Update the next entry to point to our previous entry */
    if (Next)
    {
        Next->FreePrevious.P = Prev;
    }
 
    /* Are we at the head? */
    if (Prev)
    {
        /* Nope, so update our previous entry to point to our next entry */
        Prev->FreeNext.P = Next;
    }
    else
    {
        /* Yep, so update the appropriate bucket listhead */
        MmFreeList[MmHapGetBucketId(MmHapBufferSize(FreeEntry))] = Prev;
    }
 
    /* Return the (now removed) entry */
    return FreeEntry;
}

Referenced by MmHapCoalesceFreeBuffer(), and MmHapFindBufferInFreeList().

MmHapReportHeapCorruption()

VOID MmHapReportHeapCorruption

(

_In_ PBL_FREE_HEAP_ENTRY

BufferEntry

)

Definition at line 222 of file heapalloc.c.

{
#if 0
    BOOLEAN DebuggerEnabled;
 
    BlStatusPrint(L"Heap corruption in the links surrounding %p!\r\n", BufferEntry);
 
    DebuggerEnabled = BlBdDebuggerEnabled();
    if (DebuggerEnabled)
    {
        BlStatusPrint(L"\n*** Fatal Error 0x%08x :\n                (0x%p, 0x%p, 0x%p, 0x%p)\n\r\n", 2, BufferEntry, NULL, NULL, NULL);
        __debugbreak();
    }
#else
    EfiPrintf(L"Heap corruption in the links surrounding %p!\r\n", BufferEntry);
#endif
}

Referenced by MmHapCheckBufferLinks(), and MmHapCheckFreeLinks().

MmHapUserBufferSize()

FORCEINLINE ULONG MmHapUserBufferSize

(

_In_ PVOID

FreeEntry

)

Definition at line 88 of file heapalloc.c.

{
    PBL_FREE_HEAP_ENTRY Entry = FreeEntry;
 
    /* Get the size of the buffer as the user sees it */
    return MmHapBufferSize(Entry) - FIELD_OFFSET(BL_BUSY_HEAP_ENTRY, Buffer);
}

Referenced by MmHapAddToFreeList().

Variable Documentation

HapAllocationAttributes

ULONG HapAllocationAttributes

Definition at line 59 of file heapalloc.c.

Referenced by MmHaInitialize(), and MmHapHeapAllocatorExtend().

HapInitializationStatus

ULONG HapInitializationStatus

Definition at line 56 of file heapalloc.c.

Referenced by BlMmAllocateHeap(), BlMmFreeHeap(), and MmHaInitialize().

HapMinimumHeapSize

ULONG HapMinimumHeapSize

Definition at line 58 of file heapalloc.c.

Referenced by MmHaInitialize(), and MmHapHeapAllocatorExtend().

MmFreeList

PBL_FREE_HEAP_ENTRY* MmFreeList

Definition at line 60 of file heapalloc.c.

Referenced by MmHaInitialize(), MmHapAddToFreeList(), MmHapFindBufferInFreeList(), MmHapHeapAllocatorExtend(), and MmHapRemoveBufferFromFreeList().

MmHeapBoundaries

LIST_ENTRY MmHeapBoundaries

Definition at line 57 of file heapalloc.c.

Referenced by BlMmAllocateHeap(), BlMmFreeHeap(), MmHaInitialize(), and MmHapHeapAllocatorExtend().