blkalloc.c File Reference

#include "bl.h"

Include dependency graph for blkalloc.c:

Go to the source code of this file.

Classes
struct	_BL_BLOCK_DESCRIPTOR
struct	_BL_BLOCK_ENTRY

Typedefs
typedef struct _BL_BLOCK_DESCRIPTOR	BL_BLOCK_DESCRIPTOR
typedef struct _BL_BLOCK_DESCRIPTOR *	PBL_BLOCK_DESCRIPTOR
typedef struct _BL_BLOCK_ENTRY	BL_BLOCK_ENTRY
typedef struct _BL_BLOCK_ENTRY *	PBL_BLOCK_ENTRY

Functions
BOOLEAN	MmBapCompareBlockAllocatorTableEntry (_In_ PVOID Entry, _In_ PVOID Argument1, _In_ PVOID Argument2, _In_ PVOID Argument3, _In_ PVOID Argument4)
PBL_BLOCK_DESCRIPTOR	MmBapFindBlockInformation (ULONG BlockId)
NTSTATUS	MmBapFreeBlockAllocatorDescriptor (_In_ PBL_BLOCK_DESCRIPTOR BlockInfo, _In_ PBL_BLOCK_ENTRY BlockEntry)
NTSTATUS	BlpMmDeleteBlockAllocator (_In_ ULONG BlockId)
NTSTATUS	MmBapFreeBlockAllocatorTableEntry (_In_ PVOID Entry, _In_ ULONG Index)
NTSTATUS	MmBapPurgeBlockAllocatorTableEntry (_In_ PVOID Entry)
NTSTATUS	BlpMmCreateBlockAllocator (VOID)
NTSTATUS	MmBaInitialize (VOID)

Variables
PVOID *	MmBlockAllocatorTable
ULONG	MmBlockAllocatorTableEntries
BOOLEAN	MmBlockAllocatorInitialized

Typedef Documentation

BL_BLOCK_DESCRIPTOR

typedef struct _BL_BLOCK_DESCRIPTOR BL_BLOCK_DESCRIPTOR

BL_BLOCK_ENTRY

typedef struct _BL_BLOCK_ENTRY BL_BLOCK_ENTRY

PBL_BLOCK_DESCRIPTOR

typedef struct _BL_BLOCK_DESCRIPTOR * PBL_BLOCK_DESCRIPTOR

PBL_BLOCK_ENTRY

typedef struct _BL_BLOCK_ENTRY * PBL_BLOCK_ENTRY

Function Documentation

BlpMmCreateBlockAllocator()

NTSTATUS BlpMmCreateBlockAllocator

(

VOID

)

Definition at line 213 of file blkalloc.c.

{
    PBL_BLOCK_DESCRIPTOR BlockInfo;
    ULONG BlockId;
    NTSTATUS Status;
 
    /* If the block allocator isn't initialized, bail out */
    BlockId = -1;
    if (!MmBlockAllocatorInitialized)
    {
        goto Quickie;
    }
 
    /* Allocate a block descriptor and zero it out */
    BlockInfo = BlMmAllocateHeap(sizeof(*BlockInfo));
    if (!BlockInfo)
    {
        goto Quickie;
    }
    RtlZeroMemory(BlockInfo, sizeof(*BlockInfo));
 
    /* Setup the block descriptor */
    BlockInfo->Attributes = 0;
    BlockInfo->Type = BlLoaderBlockMemory;
    BlockInfo->Unknown = 1;
    BlockInfo->Unknown2 = 1;
    BlockInfo->Size = PAGE_SIZE;
    BlockInfo->Count = 128;
    BlockInfo->Count2 = 128;
    InitializeListHead(&BlockInfo->ListHead);
 
    /* Add it to the list of block descriptors */
    Status = BlTblSetEntry(&MmBlockAllocatorTable,
                           &MmBlockAllocatorTableEntries,
                           BlockInfo,
                           &BlockId,
                           MmBapPurgeBlockAllocatorTableEntry);
    if (NT_SUCCESS(Status))
    {
        /* Add the initial reference and store the block ID */
        BlockInfo->ReferenceCount = 1;
        BlockInfo->BlockId = BlockId;
    }
 
Quickie:
    /* On failure, free the block descriptor */
    if (BlockId == -1)
    {
        BlMmFreeHeap(BlockInfo);
    }
 
    /* Return the block descriptor ID, or -1 on failure */
    return BlockId;
}

Referenced by BcInitialize().

BlpMmDeleteBlockAllocator()

NTSTATUS BlpMmDeleteBlockAllocator

(

_In_ ULONG

BlockId

)

Definition at line 88 of file blkalloc.c.

{
    NTSTATUS Status, LocalStatus;
    PBL_BLOCK_DESCRIPTOR BlockInfo;
    PLIST_ENTRY ListHead, NextEntry;
    PBL_BLOCK_ENTRY BlockEntry;
 
    /* Nothing to delete if we're not initialized */
    if (!MmBlockAllocatorInitialized)
    {
        return STATUS_UNSUCCESSFUL;
    }
 
    /* Find the block descriptor */
    BlockInfo = MmBapFindBlockInformation(BlockId);
    if (BlockInfo)
    {
        /* Assume success for now */
        Status = STATUS_SUCCESS;
 
        /* Do we have at least one reference? */
        if (BlockInfo->ReferenceCount)
        {
            /* Iterate over the allocated blocks */
            ListHead = &BlockInfo->ListHead;
            NextEntry = ListHead->Flink;
            while (NextEntry != ListHead)
            {
                /* Free each one */
                BlockEntry = CONTAINING_RECORD(NextEntry,
                                               BL_BLOCK_ENTRY,
                                               ListEntry);
                LocalStatus = MmBapFreeBlockAllocatorDescriptor(BlockInfo,
                                                                BlockEntry);
                if (!NT_SUCCESS(LocalStatus))
                {
                    /* Remember status on failure only */
                    Status = LocalStatus;
                }
            }
 
            /* Drop a reference */
            BlockInfo->ReferenceCount--;
        }
        else
        {
            /* There aren't any references, so why are we being called? */
            Status = STATUS_INVALID_PARAMETER;
        }
    }
    else
    {
        /* No block exists with this ID */
        Status = STATUS_UNSUCCESSFUL;
    }
 
    /* Return back */
    return Status;
}

Referenced by BcInitialize(), and MmBapFreeBlockAllocatorTableEntry().

MmBaInitialize()

NTSTATUS MmBaInitialize

(

VOID

)

Definition at line 271 of file blkalloc.c.

{
    NTSTATUS Status;
    ULONG Size;
 
    /* Allocate 8 table entries */
    MmBlockAllocatorTableEntries = 8;
    Size = sizeof(BL_BLOCK_DESCRIPTOR) * MmBlockAllocatorTableEntries;
    MmBlockAllocatorTable = BlMmAllocateHeap(Size);
    if (MmBlockAllocatorTable)
    {
        /* Zero them out -- we're all done */
        Status = STATUS_SUCCESS;
        RtlZeroMemory(MmBlockAllocatorTable, Size);
        MmBlockAllocatorInitialized = 1;
    }
    else
    {
        /* Bail out since we're out of memory */
        Status = STATUS_NO_MEMORY;
        MmBlockAllocatorInitialized = 0;
    }
 
    /* Return initialization status */
    return Status;
}

Referenced by BlpMmInitialize().

MmBapCompareBlockAllocatorTableEntry()

BOOLEAN MmBapCompareBlockAllocatorTableEntry	(	_In_ PVOID	Entry,
		_In_ PVOID	Argument1,
		_In_ PVOID	Argument2,
		_In_ PVOID	Argument3,
		_In_ PVOID	Argument4
	)

Definition at line 42 of file blkalloc.c.

{
    PBL_BLOCK_DESCRIPTOR BlockInfo = (PBL_BLOCK_DESCRIPTOR)Entry;
    ULONG BlockId = PtrToUlong(Argument1);
 
    /* Check if the block ID matches */
    return BlockInfo->BlockId == BlockId;
}

Referenced by MmBapFindBlockInformation().

MmBapFindBlockInformation()

PBL_BLOCK_DESCRIPTOR MmBapFindBlockInformation

(

ULONG

BlockId

)

Definition at line 58 of file blkalloc.c.

{
    ULONG EntryId;
 
    /* Find the block that matches */
    EntryId = BlockId;
    return BlTblFindEntry(MmBlockAllocatorTable,
                          MmBlockAllocatorTableEntries,
                          &EntryId,
                          MmBapCompareBlockAllocatorTableEntry,
                          UlongToPtr(EntryId),
                          NULL,
                          NULL,
                          NULL);
}

Referenced by BlpMmDeleteBlockAllocator().

MmBapFreeBlockAllocatorDescriptor()

NTSTATUS MmBapFreeBlockAllocatorDescriptor	(	_In_ PBL_BLOCK_DESCRIPTOR	BlockInfo,
		_In_ PBL_BLOCK_ENTRY	BlockEntry
	)

Definition at line 77 of file blkalloc.c.

{
    /* @TODO FIXME: Later */
    EfiPrintf(L"Block free not yet implemented\r\n");
    return STATUS_NOT_IMPLEMENTED;
}

Referenced by BlpMmDeleteBlockAllocator().

MmBapFreeBlockAllocatorTableEntry()

NTSTATUS MmBapFreeBlockAllocatorTableEntry	(	_In_ PVOID	Entry,
		_In_ ULONG	Index
	)

Definition at line 151 of file blkalloc.c.

{
    PBL_BLOCK_DESCRIPTOR BlockInfo = (PBL_BLOCK_DESCRIPTOR)Entry;
    NTSTATUS Status, LocalStatus;
 
    /* Assume success */
    Status = STATUS_SUCCESS;
 
    /* Check if there was at least one reference */
    if (BlockInfo->ReferenceCount > 1)
    {
        /* Try to delete the allocator */
        LocalStatus = BlpMmDeleteBlockAllocator(BlockInfo->BlockId);
        if (!NT_SUCCESS(LocalStatus))
        {
            /* Remember status on failure only */
            Status = LocalStatus;
        }
    }
 
    /* Now destroy the allocator's descriptor */
    LocalStatus = BlMmFreeHeap(BlockInfo);
    if (!NT_SUCCESS(LocalStatus))
    {
        /* Remember status on failure only */
        Status = LocalStatus;
    }
 
    /* Free the entry, and return failure, if any */
    MmBlockAllocatorTable[Index] = NULL;
    return Status;
}

Referenced by MmBapPurgeBlockAllocatorTableEntry().

MmBapPurgeBlockAllocatorTableEntry()

NTSTATUS MmBapPurgeBlockAllocatorTableEntry

(

_In_ PVOID

Entry

)

Definition at line 188 of file blkalloc.c.

{
    PBL_BLOCK_DESCRIPTOR BlockInfo = (PBL_BLOCK_DESCRIPTOR)Entry;
    NTSTATUS Status;
 
    /* Check if there's a reference on the block descriptor */
    if (BlockInfo->ReferenceCount)
    {
        /* Don't allow purging */
        Status = STATUS_UNSUCCESSFUL;
    }
    else
    {
        /* Free the entry */
        Status = MmBapFreeBlockAllocatorTableEntry(BlockInfo,
                                                   BlockInfo->BlockId);
    }
 
    /* Return purge status */
    return Status;
}

Referenced by BlpMmCreateBlockAllocator().

Variable Documentation

MmBlockAllocatorInitialized

BOOLEAN MmBlockAllocatorInitialized

Definition at line 17 of file blkalloc.c.

Referenced by BlpMmCreateBlockAllocator(), BlpMmDeleteBlockAllocator(), and MmBaInitialize().

MmBlockAllocatorTable

PVOID* MmBlockAllocatorTable

Definition at line 15 of file blkalloc.c.

Referenced by BlpMmCreateBlockAllocator(), MmBaInitialize(), MmBapFindBlockInformation(), and MmBapFreeBlockAllocatorTableEntry().

MmBlockAllocatorTableEntries

ULONG MmBlockAllocatorTableEntries

Definition at line 16 of file blkalloc.c.

Referenced by BlpMmCreateBlockAllocator(), MmBaInitialize(), and MmBapFindBlockInformation().