quota.c File Reference

#include <ntoskrnl.h>
#include <debug.h>

Include dependency graph for quota.c:

Go to the source code of this file.

Macros
#define	NDEBUG
#define	VALID_QUOTA_FLAGS

Functions
	_Requires_lock_held_ (PspQuotaLock)
	Returns pool quotas back to the Memory Manager when the pool quota block is no longer being used by anybody. More...
NTSTATUS NTAPI	PspChargeProcessQuotaSpecifiedPool (_In_opt_ PEPROCESS Process, _In_ PEPROCESS_QUOTA_BLOCK QuotaBlock, _In_ PS_QUOTA_TYPE QuotaType, _In_ SIZE_T Amount)
	Internal kernel function that provides the bulk logic of process quota charging, necessary for exported kernel routines needed for quota management. More...
VOID NTAPI	PspReturnProcessQuotaSpecifiedPool (_In_opt_ PEPROCESS Process, _In_ PEPROCESS_QUOTA_BLOCK QuotaBlock, _In_ PS_QUOTA_TYPE QuotaType, _In_ SIZE_T Amount)
	Internal kernel function that provides the bulk logic of process quota returning. It returns (takes away) quotas back from a process and/or quota block, which is the opposite of charging quotas. More...
VOID NTAPI	PsInitializeQuotaSystem (VOID)
	Initializes the quota system during boot phase of the system, which sets up the default quota block that is used across several processes. More...
VOID NTAPI	PspInheritQuota (_In_ PEPROCESS Process, _In_opt_ PEPROCESS ParentProcess)
	Inherits the quota block to another newborn (child) process. If there's no parent process, the default quota block is assigned. More...
VOID NTAPI	PspInsertQuotaBlock (_In_ PEPROCESS_QUOTA_BLOCK QuotaBlock)
	Inserts the new quota block into the quota list. More...
VOID NTAPI	PspDereferenceQuotaBlock (_In_opt_ PEPROCESS Process, _In_ PEPROCESS_QUOTA_BLOCK QuotaBlock)
	De-references a quota block when quotas have been returned back because of an object de-allocation or when a process gets destroyed. If the last instance that held up the block gets de-referenced the function will perform a cleanup against that block and it'll free the quota block from memory. More...
VOID NTAPI	PsReturnSharedPoolQuota (_In_ PEPROCESS_QUOTA_BLOCK QuotaBlock, _In_ SIZE_T AmountToReturnPaged, _In_ SIZE_T AmountToReturnNonPaged)
	Returns the shared (paged and non paged) pool quotas. The function is used exclusively by the Object Manager to manage quota returns handling of objects. More...
PEPROCESS_QUOTA_BLOCK NTAPI	PsChargeSharedPoolQuota (_In_ PEPROCESS Process, _In_ SIZE_T AmountToChargePaged, _In_ SIZE_T AmountToChargeNonPaged)
	Charges the shared (paged and non paged) pool quotas. The function is used exclusively by the Object Manager to manage quota charges handling of objects. More...
NTSTATUS NTAPI	PsChargeProcessPageFileQuota (_In_ PEPROCESS Process, _In_ SIZE_T Amount)
	Charges the process page file quota. The function is used internally by the kernel. More...
VOID NTAPI	PsChargePoolQuota (_In_ PEPROCESS Process, _In_ POOL_TYPE PoolType, _In_ SIZE_T Amount)
	Charges the pool quota of a given process. The kind of pool quota to charge is determined by the PoolType parameter. More...
NTSTATUS NTAPI	PsChargeProcessNonPagedPoolQuota (_In_ PEPROCESS Process, _In_ SIZE_T Amount)
	Charges the non paged pool quota of a given process. More...
NTSTATUS NTAPI	PsChargeProcessPagedPoolQuota (_In_ PEPROCESS Process, _In_ SIZE_T Amount)
	Charges the paged pool quota of a given process. More...
NTSTATUS NTAPI	PsChargeProcessPoolQuota (_In_ PEPROCESS Process, _In_ POOL_TYPE PoolType, _In_ SIZE_T Amount)
	Charges the process' quota pool. The type of quota to be charged depends upon the PoolType parameter. More...
VOID NTAPI	PsReturnPoolQuota (_In_ PEPROCESS Process, _In_ POOL_TYPE PoolType, _In_ SIZE_T Amount)
	Returns the pool quota that the process was taking up. More...
VOID NTAPI	PsReturnProcessNonPagedPoolQuota (_In_ PEPROCESS Process, _In_ SIZE_T Amount)
	Returns the non paged quota pool that the process was taking up. More...
VOID NTAPI	PsReturnProcessPagedPoolQuota (_In_ PEPROCESS Process, _In_ SIZE_T Amount)
	Returns the paged pool quota that the process was taking up. More...
NTSTATUS NTAPI	PsReturnProcessPageFileQuota (_In_ PEPROCESS Process, _In_ SIZE_T Amount)
	Returns the page file quota that the process was taking up. The function is used exclusively by the kernel. More...
NTSTATUS NTAPI	PspSetQuotaLimits (_In_ PEPROCESS Process, _In_ ULONG Unused, _In_ PVOID QuotaLimits, _In_ ULONG QuotaLimitsLength, _In_ KPROCESSOR_MODE PreviousMode)
	This function adjusts the working set limits of a process and sets up new quota limits when necessary. The function is used when the caller requests to set up new working set sizes. More...

Variables
EPROCESS_QUOTA_BLOCK	PspDefaultQuotaBlock
static LIST_ENTRY	PspQuotaBlockList = {&PspQuotaBlockList, &PspQuotaBlockList}
static KSPIN_LOCK	PspQuotaLock

Macro Definition Documentation

NDEBUG

#define NDEBUG

Definition at line 13 of file quota.c.

VALID_QUOTA_FLAGS

#define VALID_QUOTA_FLAGS

Value:

(QUOTA_LIMITS_HARDWS_MIN_ENABLE | \
                           QUOTA_LIMITS_HARDWS_MIN_DISABLE | \
                           QUOTA_LIMITS_HARDWS_MAX_ENABLE | \
                           QUOTA_LIMITS_HARDWS_MAX_DISABLE)

Definition at line 20 of file quota.c.

Function Documentation

_Requires_lock_held_()

_Requires_lock_held_

(

PspQuotaLock

)

Returns pool quotas back to the Memory Manager when the pool quota block is no longer being used by anybody.

Releases some of excess quotas in order to attempt free up some resources. This is done primarily in in case the Memory Manager fails to raise the quota limit.

Parameters

[in]

QuotaBlock

The pool quota block of which quota resources are to be sent back.

Returns

Nothing.

Remarks

The function only returns quotas back to Memory Manager that is paged or non paged. It does not return page file quotas as page file quota management is done in a different way. Furthermore, quota spin lock has to be held when returning quotas.

Parameters

[in]	QuotaType	Process pool quota type.
[out]	ReturnedQuotas	A pointer to the returned amount of quotas back to Memory Manager.

Returns

Nothing.

Remarks

The function releases excess paged or non paged pool quotas. Page file quota type is not permitted. Furthermore, quota spin lock has to be held when returning quotas.

Definition at line 47 of file quota.c.

{
    ULONG PsQuotaTypeIndex;
    SIZE_T QuotaToReturn;

    /*
     * We must be in a dispatch level interrupt here
     * as we should be under a spin lock.
     */
    ASSERT_IRQL_EQUAL(DISPATCH_LEVEL);

    /* Make sure that the quota block is not plain garbage */
    ASSERT(QuotaBlock);

    /* Loop over the Process quota types */
    for (PsQuotaTypeIndex = PsNonPagedPool; PsQuotaTypeIndex < PsPageFile; PsQuotaTypeIndex++)
    {
        /* The amount needed to return to Mm is the limit and return fields */
        QuotaToReturn = QuotaBlock->QuotaEntry[PsQuotaTypeIndex].Limit + QuotaBlock->QuotaEntry[PsQuotaTypeIndex].Return;
        MmReturnPoolQuota(PsQuotaTypeIndex, QuotaToReturn);
    }
}

PsChargePoolQuota()

VOID NTAPI PsChargePoolQuota	(	_In_ PEPROCESS	Process,
		_In_ POOL_TYPE	PoolType,
		_In_ SIZE_T	Amount
	)

Charges the pool quota of a given process. The kind of pool quota to charge is determined by the PoolType parameter.

Parameters

[in]	Process	The process which quota is to be charged.
[in]	PoolType	The pool type to choose to charge quotas (e.g. PagedPool or NonPagedPool).
[in]	Amount	The amount of quotas to charge into a process.

Returns

Nothing.

Remarks

The function raises an exception if STATUS_QUOTA_EXCEEDED status code is returned. Callers are responsible on their own to handle the raised exception.

Definition at line 775 of file quota.c.

{
    NTSTATUS Status;
    ASSERT(KeGetCurrentIrql() < DISPATCH_LEVEL);

    /* Don't do anything for the system process */
    if (Process == PsInitialSystemProcess) return;

    /* Charge the usage */
    Status = PsChargeProcessPoolQuota(Process, PoolType, Amount);
    if (!NT_SUCCESS(Status)) ExRaiseStatus(Status);
}

Referenced by FsRtlCancelNotify(), and FsRtlNotifyFilterReportChange().

PsChargeProcessNonPagedPoolQuota()

NTSTATUS NTAPI PsChargeProcessNonPagedPoolQuota	(	_In_ PEPROCESS	Process,
		_In_ SIZE_T	Amount
	)

Charges the non paged pool quota of a given process.

Parameters

[in]	Process	The process which non paged quota is to be charged.
[in]	Amount	The amount of quotas to charge into a process.

Returns

Returns STATUS_SUCCESS if quota charing has suceeded, STATUS_QUOTA_EXCEEDED is returned otherwise to indicate the caller attempted to charge quotas over the limits.

Definition at line 811 of file quota.c.

{
    /* Call the general function */
    return PsChargeProcessPoolQuota(Process, NonPagedPool, Amount);
}

Referenced by MiCreatePebOrTeb(), MiMapLockedPagesInUserSpace(), MiMapViewOfDataSection(), NtAllocateVirtualMemory(), NtFreeVirtualMemory(), and START_TEST().

PsChargeProcessPagedPoolQuota()

NTSTATUS NTAPI PsChargeProcessPagedPoolQuota	(	_In_ PEPROCESS	Process,
		_In_ SIZE_T	Amount
	)

Charges the paged pool quota of a given process.

Parameters

[in]	Process	The process which paged quota is to be charged.
[in]	Amount	The amount of quotas to charge into a process.

Returns

Returns STATUS_SUCCESS if quota charing has suceeded, STATUS_QUOTA_EXCEEDED is returned otherwise to indicate the caller attempted to charge quotas over the limits.

Definition at line 839 of file quota.c.

{
    /* Call the general function */
    return PsChargeProcessPoolQuota(Process, PagedPool, Amount);
}

Referenced by ExpAllocateHandleTable(), ExpAllocateTablePagedPool(), ExpAllocateTablePagedPoolNoZero(), and START_TEST().

PsChargeProcessPageFileQuota()

NTSTATUS NTAPI PsChargeProcessPageFileQuota	(	_In_ PEPROCESS	Process,
		_In_ SIZE_T	Amount
	)

Charges the process page file quota. The function is used internally by the kernel.

Parameters

[in]	Process	The process which page file quota is to be charged.
[in]	Amount	The amount of page file quota to charge.

Returns

Returns STATUS_SUCCESS if quota charging has been done with success, otherwise a NTSTATUS code of STATUS_PAGEFILE_QUOTA_EXCEEDED is returned.

Definition at line 738 of file quota.c.

{
    /* Don't do anything for the system process */
    if (Process == PsInitialSystemProcess) return STATUS_SUCCESS;

    return PspChargeProcessQuotaSpecifiedPool(Process, Process->QuotaBlock, PsPageFile, Amount);
}

PsChargeProcessPoolQuota()

NTSTATUS NTAPI PsChargeProcessPoolQuota	(	_In_ PEPROCESS	Process,
		_In_ POOL_TYPE	PoolType,
		_In_ SIZE_T	Amount
	)

Charges the process' quota pool. The type of quota to be charged depends upon the PoolType parameter.

Parameters

[in]	Process	The process which quota is to be charged.
[in]	PoolType	The type of quota pool to charge (e.g. PagedPool or NonPagedPool).
[in]	Amount	The amount of quotas to charge into a process.

Returns

Returns STATUS_SUCCESS if quota charing has suceeded, STATUS_QUOTA_EXCEEDED is returned otherwise to indicate the caller attempted to charge quotas over the limits.

Definition at line 872 of file quota.c.

{
    /* Don't do anything for the system process */
    if (Process == PsInitialSystemProcess) return STATUS_SUCCESS;

    return PspChargeProcessQuotaSpecifiedPool(Process,
                                              Process->QuotaBlock,
                                              (PoolType & PAGED_POOL_MASK),
                                              Amount);
}

Referenced by ExAllocatePoolWithQuotaTag(), PsChargePoolQuota(), PsChargeProcessNonPagedPoolQuota(), and PsChargeProcessPagedPoolQuota().

PsChargeSharedPoolQuota()

PEPROCESS_QUOTA_BLOCK NTAPI PsChargeSharedPoolQuota	(	_In_ PEPROCESS	Process,
		_In_ SIZE_T	AmountToChargePaged,
		_In_ SIZE_T	AmountToChargeNonPaged
	)

Charges the shared (paged and non paged) pool quotas. The function is used exclusively by the Object Manager to manage quota charges handling of objects.

Parameters

[in]	Process	The process which quotas are to be charged within its quota block.
[in]	AmountToChargePaged	The amount of paged quotas quotas to be charged.
[in]	AmountToChargeNonPaged	The amount of non paged quotas to be charged.

Returns

Returns the charged quota block, which it'll be used by the Object Manager to attach the charged quotas information to the object. If the function fails to charge quotas, NULL is returned to the caller.

Definition at line 674 of file quota.c.

{
    NTSTATUS Status;

    /* Sanity checks */
    ASSERT(Process);
    ASSERT(Process->QuotaBlock);

    /* Do we have some paged pool quota to charge? */
    if (AmountToChargePaged != 0)
    {
        /* We do, charge! */
        Status = PspChargeProcessQuotaSpecifiedPool(NULL, Process->QuotaBlock, PsPagedPool, AmountToChargePaged);
        if (!NT_SUCCESS(Status))
        {
            DPRINT1("PsChargeSharedPoolQuota(): Failed to charge the shared pool quota (Status 0x%lx)\n", Status);
            return NULL;
        }
    }

    /* Do we have some non paged pool quota to charge? */
    if (AmountToChargeNonPaged != 0)
    {
        /* We do, charge! */
        Status = PspChargeProcessQuotaSpecifiedPool(NULL, Process->QuotaBlock, PsNonPagedPool, AmountToChargeNonPaged);
        if (!NT_SUCCESS(Status))
        {
            DPRINT1("PsChargeSharedPoolQuota(): Failed to charge the shared pool quota (Status 0x%lx). Attempting to return some paged pool back...\n", Status);
            PspReturnProcessQuotaSpecifiedPool(NULL, Process->QuotaBlock, PsPagedPool, AmountToChargePaged);
            return NULL;
        }
    }

    /* We have charged the quotas of an object, increment the reference */
    InterlockedIncrementSizeT(&Process->QuotaBlock->ReferenceCount);

    DPRINT("PsChargeSharedPoolQuota(): Amount charged (paged %lu --  non paged %lu)\n", AmountToChargePaged, AmountToChargeNonPaged);
    return Process->QuotaBlock;
}

Referenced by ObpChargeQuotaForObject().

PsInitializeQuotaSystem()

VOID NTAPI PsInitializeQuotaSystem

(

VOID

)

Initializes the quota system during boot phase of the system, which sets up the default quota block that is used across several processes.

Returns

Nothing.

Definition at line 443 of file quota.c.

{
    /* Initialize the default block */
    RtlZeroMemory(&PspDefaultQuotaBlock, sizeof(PspDefaultQuotaBlock));

    /* Assign the default quota limits */
    PspDefaultQuotaBlock.QuotaEntry[PsNonPagedPool].Limit = (SIZE_T)-1;
    PspDefaultQuotaBlock.QuotaEntry[PsPagedPool].Limit = (SIZE_T)-1;
    PspDefaultQuotaBlock.QuotaEntry[PsPageFile].Limit = (SIZE_T)-1;

    /*
     * Set up the count references as the
     * default block will going to be used.
     */
    PspDefaultQuotaBlock.ReferenceCount = 1;
    PspDefaultQuotaBlock.ProcessCount = 1;

    /* Assign that block to initial process */
    PsGetCurrentProcess()->QuotaBlock = &PspDefaultQuotaBlock;
}

Referenced by ObInitSystem().

PspChargeProcessQuotaSpecifiedPool()

NTSTATUS NTAPI PspChargeProcessQuotaSpecifiedPool	(	_In_opt_ PEPROCESS	Process,
		_In_ PEPROCESS_QUOTA_BLOCK	QuotaBlock,
		_In_ PS_QUOTA_TYPE	QuotaType,
		_In_ SIZE_T	Amount
	)

Internal kernel function that provides the bulk logic of process quota charging, necessary for exported kernel routines needed for quota management.

Parameters

[in]	Process	A process, represented as a EPROCESS object. This parameter is used to charge the own process' quota usage.
[in]	QuotaBlock	The quota block which quotas are to be charged. This block can either come from the process itself or from an object with specified quota charges.
[in]	QuotaType	The quota type which quota in question is to be charged. The permitted types are PsPagedPool, PsNonPagedPool and PsPageFile.
[in]	Amount	The amount of quota to be charged.

Returns

Returns STATUS_SUCCESS if quota charging has been done successfully without problemns. STATUS_QUOTA_EXCEEDED is returned if the caller wants to charge quotas with amount way over the limits. STATUS_PAGEFILE_QUOTA_EXCEEDED is returned for the same situation but specific to page files instead.

Definition at line 195 of file quota.c.

{
    KIRQL OldIrql;
    SIZE_T ReturnedQuotas;
    SIZE_T UpdatedLimit;

    /* Sanity checks */
    ASSERT(QuotaType < PsQuotaTypes);
    ASSERT((SSIZE_T)Amount >= 0);

    /* Guard ourselves in a spin lock */
    KeAcquireSpinLock(&PspQuotaLock, &OldIrql);

    /* Are we within the bounds of quota limit? */
    if (QuotaBlock->QuotaEntry[QuotaType].Usage + Amount >
        QuotaBlock->QuotaEntry[QuotaType].Limit &&
        QuotaBlock != &PspDefaultQuotaBlock)
    {
        /* We aren't... Is this a page file quota charging? */
        if (QuotaType == PsPageFile)
        {
            /* It is, return the appropriate status code */
            DPRINT1("PspChargeProcessQuotaSpecifiedPool(): Quota amount exceeds the limit on page file quota (limit -- %lu || amount -- %lu)\n",
                    QuotaBlock->QuotaEntry[QuotaType].Limit, Amount);
            return STATUS_PAGEFILE_QUOTA_EXCEEDED;
        }

        /*
         * This is not a page file charge. What we can do at best
         * in this scenario is to attempt to raise (expand) the
         * quota limit charges of the block.
         */
        if (!MmRaisePoolQuota(QuotaType,
                              QuotaBlock->QuotaEntry[QuotaType].Limit,
                              &UpdatedLimit))
        {
            /*
             * We can't? It could be that we must free
             * up some resources in order to raise the
             * limit, which in that case we must return
             * the excess of quota that hasn't been
             * returned. If we haven't returned anything
             * then what we're doing here is futile.
             * Bail out...
             */
            PspReturnExcessQuotas(QuotaType, &ReturnedQuotas);
            if (ReturnedQuotas == 0)
            {
                DPRINT1("PspChargeProcessQuotaSpecifiedPool(): Failed to free some resources in order to raise quota limits...\n");
                KeReleaseSpinLock(&PspQuotaLock, OldIrql);
                return STATUS_QUOTA_EXCEEDED;
            }

            /* Try to raise the quota limits again */
            MmRaisePoolQuota(QuotaType,
                             QuotaBlock->QuotaEntry[QuotaType].Limit,
                             &UpdatedLimit);
        }

        /* Enforce a new raised limit */
        InterlockedExchangeSizeT(&QuotaBlock->QuotaEntry[QuotaType].Limit, UpdatedLimit);

        /*
         * Now determine if the current usage and the
         * amounting by the caller still exceeds the
         * quota limit of the process. If it's still
         * over the limit then there's nothing we can
         * do, so fail.
         */
        if (QuotaBlock->QuotaEntry[QuotaType].Usage + Amount >
            QuotaBlock->QuotaEntry[QuotaType].Limit)
        {
            DPRINT1("PspChargeProcessQuotaSpecifiedPool(): Quota amount exceeds the limit (limit -- %lu || amount -- %lu)\n",
                    QuotaBlock->QuotaEntry[QuotaType].Limit, Amount);
            return STATUS_QUOTA_EXCEEDED;
        }
    }

    /* Update the quota usage */
    InterlockedExchangeAddSizeT(&QuotaBlock->QuotaEntry[QuotaType].Usage, Amount);

    /* Update the entry peak if it's less than the usage */
    if (QuotaBlock->QuotaEntry[QuotaType].Peak <
        QuotaBlock->QuotaEntry[QuotaType].Usage)
    {
        InterlockedExchangeSizeT(&QuotaBlock->QuotaEntry[QuotaType].Peak,
                                 QuotaBlock->QuotaEntry[QuotaType].Usage);
    }

    /* Are we being given a process as well? */
    if (Process)
    {
        /* We're being given, check that's not a system one */
        ASSERT(Process != PsInitialSystemProcess);

        InterlockedExchangeAddSizeT(&Process->QuotaUsage[QuotaType], Amount);

        /*
         * OK, we've now updated the quota usage of the process
         * based upon the amount that the caller wanted to charge.
         * Although the peak of process quota can be less than it was
         * before so update the peaks as well accordingly.
         */
        if (Process->QuotaPeak[QuotaType] < Process->QuotaUsage[QuotaType])
        {
            InterlockedExchangeSizeT(&Process->QuotaPeak[QuotaType],
                                     Process->QuotaUsage[QuotaType]);
        }
    }

    /* Release the lock */
    KeReleaseSpinLock(&PspQuotaLock, OldIrql);
    return STATUS_SUCCESS;
}

Referenced by PsChargeProcessPageFileQuota(), PsChargeProcessPoolQuota(), and PsChargeSharedPoolQuota().

PspDereferenceQuotaBlock()

VOID NTAPI PspDereferenceQuotaBlock	(	_In_opt_ PEPROCESS	Process,
		_In_ PEPROCESS_QUOTA_BLOCK	QuotaBlock
	)

De-references a quota block when quotas have been returned back because of an object de-allocation or when a process gets destroyed. If the last instance that held up the block gets de-referenced the function will perform a cleanup against that block and it'll free the quota block from memory.

Parameters

[in]	Process	A pointer to a process that de-references the quota block.
[in]	QuotaBlock	A pointer to a quota block that is to be de-referenced. This block can come from a process that references it or an object.

Returns

Nothing.

Definition at line 553 of file quota.c.

{
    ULONG PsQuotaTypeIndex;
    KIRQL OldIrql;

    /* Make sure the quota block is not trash */
    ASSERT(QuotaBlock);

    /* Iterate over the process quota types if we have a process */
    if (Process)
    {
        for (PsQuotaTypeIndex = PsNonPagedPool; PsQuotaTypeIndex < PsQuotaTypes; PsQuotaTypeIndex++)
        {
            /*
             * We need to make sure that the quota usage
             * uniquely associated with the process is 0
             * on that moment the process gets destroyed.
             */
            ASSERT(Process->QuotaUsage[PsQuotaTypeIndex] == 0);
        }

        /* As the process is now gone, decrement the process count */
        InterlockedDecrementUL(&QuotaBlock->ProcessCount);
    }

    /* If no one is using this block, begin to destroy it */
    if (QuotaBlock != &PspDefaultQuotaBlock &&
        InterlockedDecrementUL(&QuotaBlock->ReferenceCount) == 0)
    {
        /* Acquire the quota lock */
        KeAcquireSpinLock(&PspQuotaLock, &OldIrql);

        /* Return all the quotas back to Mm and remove the quota from list */
        PspReturnQuotasOnDestroy(QuotaBlock);
        RemoveEntryList(&QuotaBlock->QuotaList);

        /* Release the lock and free the block */
        KeReleaseSpinLock(&PspQuotaLock, OldIrql);
        ExFreePoolWithTag(QuotaBlock, TAG_QUOTA_BLOCK);
    }
}

Referenced by PspDeleteProcess(), and PsReturnSharedPoolQuota().

PspInheritQuota()

VOID NTAPI PspInheritQuota	(	_In_ PEPROCESS	Process,
		_In_opt_ PEPROCESS	ParentProcess
	)

Inherits the quota block to another newborn (child) process. If there's no parent process, the default quota block is assigned.

Parameters

[in]	Process	The child process which quota block is to be given.
[in]	ParentProcess	The parent process.

Returns

Nothing.

Definition at line 483 of file quota.c.

{
    PEPROCESS_QUOTA_BLOCK QuotaBlock;

    if (ParentProcess != NULL)
    {
        ASSERT(ParentProcess->QuotaBlock != NULL);
        QuotaBlock = ParentProcess->QuotaBlock;
    }
    else
    {
        QuotaBlock = &PspDefaultQuotaBlock;
    }

    InterlockedIncrementSizeT(&QuotaBlock->ProcessCount);
    InterlockedIncrementSizeT(&QuotaBlock->ReferenceCount);

    Process->QuotaBlock = QuotaBlock;
}

PspInsertQuotaBlock()

VOID NTAPI PspInsertQuotaBlock

(

_In_ PEPROCESS_QUOTA_BLOCK

QuotaBlock

)

Inserts the new quota block into the quota list.

Parameters

[in]

QuotaBlock

The new quota block.

Returns

Nothing.

Definition at line 518 of file quota.c.

{
    KIRQL OldIrql;

    KeAcquireSpinLock(&PspQuotaLock, &OldIrql);
    InsertTailList(&PspQuotaBlockList, &QuotaBlock->QuotaList);
    KeReleaseSpinLock(&PspQuotaLock, OldIrql);
}

Referenced by PspSetQuotaLimits().

PspReturnProcessQuotaSpecifiedPool()

VOID NTAPI PspReturnProcessQuotaSpecifiedPool	(	_In_opt_ PEPROCESS	Process,
		_In_ PEPROCESS_QUOTA_BLOCK	QuotaBlock,
		_In_ PS_QUOTA_TYPE	QuotaType,
		_In_ SIZE_T	Amount
	)

Internal kernel function that provides the bulk logic of process quota returning. It returns (takes away) quotas back from a process and/or quota block, which is the opposite of charging quotas.

Parameters

[in]	Process	A process, represented as a EPROCESS object. This parameter is used to return the own process' quota usage.
[in]	QuotaBlock	The quota block which quotas are to be returned. This block can either come from the process itself or from an object with specified quota charges.
[in]	QuotaType	The quota type which quota in question is to be returned. The permitted types are PsPagedPool, PsNonPagedPool and PsPageFile.
[in]	Amount	The amount of quota to be returned.

Returns

Nothing.

Definition at line 345 of file quota.c.

{
    KIRQL OldIrql;
    SIZE_T ReturnThreshold;
    SIZE_T AmountToReturn = 0;

    /* Sanity checks */
    ASSERT(QuotaType < PsQuotaTypes);
    ASSERT((SSIZE_T)Amount >= 0);

    /* Guard ourselves in a spin lock */
    KeAcquireSpinLock(&PspQuotaLock, &OldIrql);

    /* Does the caller return more quota than it was previously charged? */
    if ((Process && Process->QuotaUsage[QuotaType] < Amount) ||
        QuotaBlock->QuotaEntry[QuotaType].Usage < Amount)
    {
        /* It does, crash the system! */
        KeBugCheckEx(QUOTA_UNDERFLOW,
                     (ULONG_PTR)Process,
                     (ULONG_PTR)QuotaType,
                     Process ? (ULONG_PTR)Process->QuotaUsage[QuotaType] :
                               QuotaBlock->QuotaEntry[QuotaType].Usage,
                     (ULONG_PTR)Amount);
    }

    /* The return threshold can be non paged or paged */
    ReturnThreshold = QuotaType ? PSP_NON_PAGED_POOL_QUOTA_THRESHOLD : PSP_PAGED_POOL_QUOTA_THRESHOLD;

    /*
     * We need to trim the quota limits based on the
     * amount we're going to return quotas back.
     */
    if ((QuotaType != PsPageFile && QuotaBlock != &PspDefaultQuotaBlock) &&
        (QuotaBlock->QuotaEntry[QuotaType].Limit > QuotaBlock->QuotaEntry[QuotaType].Usage + ReturnThreshold))
    {
        /*
         * If the amount to return exceeds the threshold,
         * the new amount becomes the default, otherwise
         * the amount is just the one given by the caller.
         */
        AmountToReturn = min(Amount, ReturnThreshold);

        /* Add up the lots to the Return field */
        InterlockedExchangeAddSizeT(&QuotaBlock->QuotaEntry[QuotaType].Return, AmountToReturn);

        /*
         * If the amount to return exceeds the threshold then
         * we have lots of quota to return to Mm. So do it so
         * and zerou out the Return field.
         */
        if (QuotaBlock->QuotaEntry[QuotaType].Return > ReturnThreshold)
        {
            MmReturnPoolQuota(QuotaType, QuotaBlock->QuotaEntry[QuotaType].Return);
            InterlockedExchangeSizeT(QuotaBlock->QuotaEntry[QuotaType].Return, 0);
        }

        /* And try to trim the limit */
        InterlockedExchangeSizeT(&QuotaBlock->QuotaEntry[QuotaType].Limit,
                                 QuotaBlock->QuotaEntry[QuotaType].Limit - AmountToReturn);
    }

    /* Update the usage member of the block */
    InterlockedExchangeAddSizeT(&QuotaBlock->QuotaEntry[QuotaType].Usage, -(LONG_PTR)Amount);

    /* Are we being given a process? */
    if (Process)
    {
        /* We're being given, check that's not a system one  */
        ASSERT(Process != PsInitialSystemProcess);

        /* Decrease the process' quota usage */
        InterlockedExchangeAddSizeT(&Process->QuotaUsage[QuotaType], -(LONG_PTR)Amount);
    }

    /* We're done, release the lock */
    KeReleaseSpinLock(&PspQuotaLock, OldIrql);
}

Referenced by PsChargeSharedPoolQuota(), PsReturnPoolQuota(), PsReturnProcessPageFileQuota(), and PsReturnSharedPoolQuota().

PspSetQuotaLimits()

NTSTATUS NTAPI PspSetQuotaLimits	(	_In_ PEPROCESS	Process,
		_In_ ULONG	Unused,
		_In_ PVOID	QuotaLimits,
		_In_ ULONG	QuotaLimitsLength,
		_In_ KPROCESSOR_MODE	PreviousMode
	)

This function adjusts the working set limits of a process and sets up new quota limits when necessary. The function is used when the caller requests to set up new working set sizes.

Parameters

[in]	Process	The process which quota limits or working set sizes are to be changed.
[in]	Unused	This parameter is unused.
[in]	QuotaLimits	An arbitrary pointer that points to a quota limits structure, needed to determine on setting up new working set sizes.
[in]	QuotaLimitsLength	The length of QuotaLimits buffer, which size is expressed in bytes.
[in]	PreviousMode	The processor level access mode.

Returns

Returns STATUS_SUCCESS if the function has completed successfully. STATUS_INVALID_PARAMETER is returned if the caller has given a quota limits structure with invalid data. STATUS_INFO_LENGTH_MISMATCH is returned if the length of QuotaLimits pointed by QuotaLimitsLength is not right. STATUS_PRIVILEGE_NOT_HELD is returned if the calling thread of the process doesn't hold the necessary right privilege to increase quotas. STATUS_NO_MEMORY is returned if a memory pool allocation has failed. A failure NTSTATUS code is returned otherwise.

Definition at line 1045 of file quota.c.

{
    QUOTA_LIMITS_EX CapturedQuotaLimits;
    PEPROCESS_QUOTA_BLOCK QuotaBlock, OldQuotaBlock;
    BOOLEAN IncreaseOkay;
    KAPC_STATE SavedApcState;
    NTSTATUS Status;

    UNREFERENCED_PARAMETER(Unused);

    _SEH2_TRY
    {
        ProbeForRead(QuotaLimits, QuotaLimitsLength, sizeof(ULONG));

        /* Check if we have the basic or extended structure */
        if (QuotaLimitsLength == sizeof(QUOTA_LIMITS))
        {
            /* Copy the basic structure, zero init the remaining fields */
            RtlCopyMemory(&CapturedQuotaLimits, QuotaLimits, sizeof(QUOTA_LIMITS));
            CapturedQuotaLimits.WorkingSetLimit = 0;
            CapturedQuotaLimits.Reserved2 = 0;
            CapturedQuotaLimits.Reserved3 = 0;
            CapturedQuotaLimits.Reserved4 = 0;
            CapturedQuotaLimits.CpuRateLimit.RateData = 0;
            CapturedQuotaLimits.Flags = 0;
        }
        else if (QuotaLimitsLength == sizeof(QUOTA_LIMITS_EX))
        {
            /* Copy the full structure */
            RtlCopyMemory(&CapturedQuotaLimits, QuotaLimits, sizeof(QUOTA_LIMITS_EX));

            /* Verify that the caller passed valid flags */
            if ((CapturedQuotaLimits.Flags & ~VALID_QUOTA_FLAGS) ||
                ((CapturedQuotaLimits.Flags & QUOTA_LIMITS_HARDWS_MIN_ENABLE) &&
                 (CapturedQuotaLimits.Flags & QUOTA_LIMITS_HARDWS_MIN_DISABLE)) ||
                ((CapturedQuotaLimits.Flags & QUOTA_LIMITS_HARDWS_MAX_ENABLE) &&
                 (CapturedQuotaLimits.Flags & QUOTA_LIMITS_HARDWS_MAX_DISABLE)))
            {
                DPRINT1("Invalid quota flags: 0x%lx\n", CapturedQuotaLimits.Flags);
                _SEH2_YIELD(return STATUS_INVALID_PARAMETER);
            }

            /* Verify that the caller didn't pass reserved values */
            if ((CapturedQuotaLimits.WorkingSetLimit != 0) ||
                (CapturedQuotaLimits.Reserved2 != 0) ||
                (CapturedQuotaLimits.Reserved3 != 0) ||
                (CapturedQuotaLimits.Reserved4 != 0) ||
                (CapturedQuotaLimits.CpuRateLimit.RateData != 0))
            {
                DPRINT1("Invalid value: (%lx,%lx,%lx,%lx,%lx)\n",
                        CapturedQuotaLimits.WorkingSetLimit,
                        CapturedQuotaLimits.Reserved2,
                        CapturedQuotaLimits.Reserved3,
                        CapturedQuotaLimits.Reserved4,
                        CapturedQuotaLimits.CpuRateLimit.RateData);
                _SEH2_YIELD(return STATUS_INVALID_PARAMETER);
            }
        }
        else
        {
            DPRINT1("Invalid quota size: 0x%lx\n", QuotaLimitsLength);
            _SEH2_YIELD(return STATUS_INFO_LENGTH_MISMATCH);
        }
    }
    _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
    {
        DPRINT1("Exception while copying data\n");
        _SEH2_YIELD(return _SEH2_GetExceptionCode());
    }
    _SEH2_END;

    /* Check the caller changes the working set size limits */
    if ((CapturedQuotaLimits.MinimumWorkingSetSize != 0) &&
        (CapturedQuotaLimits.MaximumWorkingSetSize != 0))
    {
        /* Check for special case: trimming the WS */
        if ((CapturedQuotaLimits.MinimumWorkingSetSize == SIZE_T_MAX) &&
            (CapturedQuotaLimits.MaximumWorkingSetSize == SIZE_T_MAX))
        {
            /* No increase allowed */
            IncreaseOkay = FALSE;
        }
        else
        {
            /* Check if the caller has the required privilege */
            IncreaseOkay = SeSinglePrivilegeCheck(SeIncreaseQuotaPrivilege,
                                                  PreviousMode);
        }

        /* Attach to the target process and disable APCs */
        KeStackAttachProcess(&Process->Pcb, &SavedApcState);
        KeEnterGuardedRegion();

        /* Call Mm to adjust the process' working set size */
        Status = MmAdjustWorkingSetSize(CapturedQuotaLimits.MinimumWorkingSetSize,
                                        CapturedQuotaLimits.MaximumWorkingSetSize,
                                        0,
                                        IncreaseOkay);

        /* Bring back APCs and detach from the process */
        KeLeaveGuardedRegion();
        KeUnstackDetachProcess(&SavedApcState);
    }
    else if (Process->QuotaBlock == &PspDefaultQuotaBlock)
    {
        /* Check if the caller has the required privilege */
        if (!SeSinglePrivilegeCheck(SeIncreaseQuotaPrivilege, PreviousMode))
        {
            return STATUS_PRIVILEGE_NOT_HELD;
        }

        /* Allocate a new quota block */
        QuotaBlock = ExAllocatePoolWithTag(NonPagedPool,
                                           sizeof(EPROCESS_QUOTA_BLOCK),
                                           TAG_QUOTA_BLOCK);
        if (QuotaBlock == NULL)
        {
            ObDereferenceObject(Process);
            return STATUS_NO_MEMORY;
        }

        /* Initialize the quota block */
        QuotaBlock->ReferenceCount = 1;
        QuotaBlock->ProcessCount = 1;
        QuotaBlock->QuotaEntry[PsNonPagedPool].Peak = Process->QuotaPeak[PsNonPagedPool];
        QuotaBlock->QuotaEntry[PsPagedPool].Peak = Process->QuotaPeak[PsPagedPool];
        QuotaBlock->QuotaEntry[PsPageFile].Peak = Process->QuotaPeak[PsPageFile];
        QuotaBlock->QuotaEntry[PsNonPagedPool].Limit = PspDefaultQuotaBlock.QuotaEntry[PsNonPagedPool].Limit;
        QuotaBlock->QuotaEntry[PsPagedPool].Limit = PspDefaultQuotaBlock.QuotaEntry[PsPagedPool].Limit;
        QuotaBlock->QuotaEntry[PsPageFile].Limit = PspDefaultQuotaBlock.QuotaEntry[PsPageFile].Limit;

        /* Try to exchange the quota block, if that failed, just drop it */
        OldQuotaBlock = InterlockedCompareExchangePointer((PVOID*)&Process->QuotaBlock,
                                                          QuotaBlock,
                                                          &PspDefaultQuotaBlock);
        if (OldQuotaBlock == &PspDefaultQuotaBlock)
        {
            /* Success, insert the new quota block */
            PspInsertQuotaBlock(QuotaBlock);
        }
        else
        {
            /* Failed, free the quota block and ignore it */
            ExFreePoolWithTag(QuotaBlock, TAG_QUOTA_BLOCK);
        }

        Status = STATUS_SUCCESS;
    }
    else
    {
        Status = STATUS_SUCCESS;
    }

    return Status;
}

Referenced by NtSetInformationProcess().

PsReturnPoolQuota()

VOID NTAPI PsReturnPoolQuota	(	_In_ PEPROCESS	Process,
		_In_ POOL_TYPE	PoolType,
		_In_ SIZE_T	Amount
	)

Returns the pool quota that the process was taking up.

Parameters

[in]	Process	The process which quota is to be returned.
[in]	PoolType	The type of quota pool to return (e.g. PagedPool or NonPagedPool).
[in]	Amount	The amount of quotas to return from a process.

Returns

Nothing.

Definition at line 907 of file quota.c.

{
    /* Don't do anything for the system process */
    if (Process == PsInitialSystemProcess) return;

    PspReturnProcessQuotaSpecifiedPool(Process,
                                       Process->QuotaBlock,
                                       (PoolType & PAGED_POOL_MASK),
                                       Amount);
}

Referenced by ExFreePoolWithTag(), ExReturnPoolQuota(), PsReturnProcessNonPagedPoolQuota(), and PsReturnProcessPagedPoolQuota().

PsReturnProcessNonPagedPoolQuota()

NTKERNELAPI VOID NTAPI PsReturnProcessNonPagedPoolQuota	(	_In_ PEPROCESS	Process,
		_In_ SIZE_T	Amount
	)

Returns the non paged quota pool that the process was taking up.

Parameters

[in]	Process	The process which non paged quota is to be returned.
[in]	Amount	The amount of quotas to return from a process.

Returns

Nothing.

Definition at line 938 of file quota.c.

{
    /* Don't do anything for the system process */
    if (Process == PsInitialSystemProcess) return;

    PsReturnPoolQuota(Process, NonPagedPool, Amount);
}

Referenced by MiMapViewOfDataSection(), MiUnmapLockedPagesInUserSpace(), MiUnmapViewOfSection(), MmCleanProcessAddressSpace(), MmDeleteTeb(), NtFreeVirtualMemory(), PspDeleteProcess(), and START_TEST().

PsReturnProcessPagedPoolQuota()

VOID NTAPI PsReturnProcessPagedPoolQuota	(	_In_ PEPROCESS	Process,
		_In_ SIZE_T	Amount
	)

Returns the paged pool quota that the process was taking up.

Parameters

[in]	Process	The process which paged pool quota is to be returned.
[in]	Amount	The amount of quotas to return from a process.

Returns

Nothing.

Definition at line 965 of file quota.c.

{
    /* Don't do anything for the system process */
    if (Process == PsInitialSystemProcess) return;

    PsReturnPoolQuota(Process, PagedPool, Amount);
}

Referenced by ExpAllocateHandleTable(), ExpFreeHandleTable(), ExpFreeTablePagedPool(), FsRtlCancelNotify(), FsRtlNotifyCleanup(), FsRtlNotifyCompleteIrp(), FsRtlNotifyFilterReportChange(), and START_TEST().

PsReturnProcessPageFileQuota()

NTSTATUS NTAPI PsReturnProcessPageFileQuota	(	_In_ PEPROCESS	Process,
		_In_ SIZE_T	Amount
	)

Returns the page file quota that the process was taking up. The function is used exclusively by the kernel.

Parameters

[in]	Process	The process which pagefile quota is to be returned.
[in]	Amount	The amount of quotas to return from a process.

Returns

Returns STATUS_SUCCESS.

Definition at line 993 of file quota.c.

{
    /* Don't do anything for the system process */
    if (Process == PsInitialSystemProcess) return STATUS_SUCCESS;

    PspReturnProcessQuotaSpecifiedPool(Process, Process->QuotaBlock, PsPageFile, Amount);
    return STATUS_SUCCESS;
}

PsReturnSharedPoolQuota()

VOID NTAPI PsReturnSharedPoolQuota	(	_In_ PEPROCESS_QUOTA_BLOCK	QuotaBlock,
		_In_ SIZE_T	AmountToReturnPaged,
		_In_ SIZE_T	AmountToReturnNonPaged
	)

Returns the shared (paged and non paged) pool quotas. The function is used exclusively by the Object Manager to manage quota returns handling of objects.

Parameters

[in]	QuotaBlock	The quota block which quotas are to be returned.
[in]	AmountToReturnPaged	The amount of paged quotas quotas to be returned.
[in]	AmountToReturnNonPaged	The amount of non paged quotas to be returned.

Returns

Nothing.

Definition at line 621 of file quota.c.

{
    /* Sanity check */
    ASSERT(QuotaBlock);

    /* Return the pool quotas if there're any */
    if (AmountToReturnPaged != 0)
    {
        PspReturnProcessQuotaSpecifiedPool(NULL, QuotaBlock, PsPagedPool, AmountToReturnPaged);
    }

    if (AmountToReturnNonPaged != 0)
    {
        PspReturnProcessQuotaSpecifiedPool(NULL, QuotaBlock, PsNonPagedPool, AmountToReturnNonPaged);
    }

    DPRINT("PsReturnSharedPoolQuota(): Amount returned back (paged %lu -- non paged %lu)\n", AmountToReturnPaged, AmountToReturnNonPaged);

    /* Dereference the quota block */
    PspDereferenceQuotaBlock(NULL, QuotaBlock);
}

Referenced by ObpDeallocateObject().

Variable Documentation

PspDefaultQuotaBlock

EPROCESS_QUOTA_BLOCK PspDefaultQuotaBlock

Definition at line 16 of file quota.c.

Referenced by NtQueryInformationProcess(), PsInitializeQuotaSystem(), PspChargeProcessQuotaSpecifiedPool(), PspDereferenceQuotaBlock(), PspInheritQuota(), PspReturnProcessQuotaSpecifiedPool(), and PspSetQuotaLimits().

PspQuotaBlockList

LIST_ENTRY PspQuotaBlockList = {&PspQuotaBlockList, &PspQuotaBlockList}

static

Definition at line 17 of file quota.c.

Referenced by PspInsertQuotaBlock().

PspQuotaLock

KSPIN_LOCK PspQuotaLock

static

Definition at line 18 of file quota.c.

Referenced by PspChargeProcessQuotaSpecifiedPool(), PspDereferenceQuotaBlock(), PspInsertQuotaBlock(), and PspReturnProcessQuotaSpecifiedPool().