422 lines
11 KiB
C
422 lines
11 KiB
C
#include "wdmsys.h"
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#pragma LOCKED_CODE
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#pragma LOCKED_DATA
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//
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// Robust checking enables bugchecks in the retail version of this component.
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//
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BOOL gbRobustChecking = FALSE;
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#if 0
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//
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// PagedCode: This routine should be used in routines that touch pageable
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// code and data. Notice that this is not the PAGED_CODE() macro so that it
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// will be in the retail code.
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//
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void
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PagedCode(
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void
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)
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{
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if( KeGetCurrentIrql() > APC_LEVEL )
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{
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KeBugCheckEx(AUDIO_BUGCHECK_CODE,AUDIO_NOT_BELOW_DISPATCH_LEVEL,0,0,0);
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}
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}
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void
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ValidatePassiveLevel(
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void
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)
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{
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if( KeGetCurrentIrql() != PASSIVE_LEVEL )
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{
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KeBugCheckEx(AUDIO_BUGCHECK_CODE,AUDIO_NOT_AT_PASSIVE_LEVEL,0,0,0);
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}
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}
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//
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// If bExclusive is TRUE, the caller wants to know if the mutex is acquired multiple
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// times on the same thread. If they don't want this checking done, they should
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// set bExclusive to FALSE.
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//
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NTSTATUS
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AudioEnterMutex(
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IN PKMUTEX pmutex,
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IN BOOL bExclusive
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)
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{
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PRKTHREAD pkt;
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NTSTATUS Status;
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LONG lMutexState;
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Status = KeWaitForSingleObject ( pmutex,Executive,KernelMode,FALSE,NULL ) ;
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if( gbRobustChecking && bExclusive )
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{
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//
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// After entering the mutex, we sanity check our nested count, but we
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// only do this if we need to. If the caller said that they designed the
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// code only for exclusive access, we'll bugcheck if we get nested.
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//
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if( (lMutexState = KeReadStateMutex(pmutex)) < 0 )
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{
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//
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// Every time you acquire a mutex the state will be decremented. 1 means
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// that it's available, 0 means it's held, -1 means this is the second time
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// it's acquired, -2 means it's the third and so on. Thus, if we're nested
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// on this thread, we'll end up here.
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//
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KeBugCheckEx(AUDIO_BUGCHECK_CODE,
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AUDIO_NESTED_MUTEX_SITUATION,
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(ULONG_PTR)pmutex,
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lMutexState,
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0);
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}
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}
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return Status;
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}
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//
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// This routine yields if we're at PASSIVE_LEVEL
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//
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void
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AudioPerformYield(
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void
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)
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{
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PRKTHREAD pthrd;
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KPRIORITY kpriority;
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//
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// After releasing the mutex we want to yield execution to all other threads
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// on the machine to try to expose preemption windows.
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//
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if( ( gbRobustChecking ) &&
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( KeGetCurrentIrql() == PASSIVE_LEVEL ) )
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{
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if( (pthrd = KeGetCurrentThread()) )
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{
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kpriority = KeQueryPriorityThread(KeGetCurrentThread());
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//
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// Lower this thrread's priority so another thread will
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// get scheduled.
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//
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KeSetPriorityThread(pthrd,1); // Is that low enough?
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//
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// This might be overkill, but yield.
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//
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ZwYieldExecution();
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//
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// Now restore the priority for this thread and party on.
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//
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KeSetPriorityThread(pthrd,kpriority);
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}
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}
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}
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void
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AudioLeaveMutex(
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IN PKMUTEX pmutex
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)
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{
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PRKTHREAD pthrd;
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KPRIORITY kpriority;
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KeReleaseMutex ( pmutex, FALSE ) ;
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AudioPerformYield();
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}
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NTSTATUS
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AudioIoCallDriver (
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IN PDEVICE_OBJECT pDevice,
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IN PIRP pIrp
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)
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{
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NTSTATUS Status;
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Status = IoCallDriver(pDevice,pIrp);
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AudioPerformYield();
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return Status;
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}
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void
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AudioEnterSpinLock(
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IN PKSPIN_LOCK pSpinLock,
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OUT PKIRQL pOldIrql
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)
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{
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//
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// KeAcquireSpinLock can only be called less then or equal to dispatch level.
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// let's verify that here.
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//
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if( ( gbRobustChecking ) &&
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( KeGetCurrentIrql() > DISPATCH_LEVEL ) )
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{
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KeBugCheckEx(AUDIO_BUGCHECK_CODE,
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AUDIO_INVALID_IRQL_LEVEL,
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0,
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0,
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0);
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}
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KeAcquireSpinLock ( pSpinLock, pOldIrql ) ;
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}
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void
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AudioLeaveSpinLock(
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IN PKSPIN_LOCK pSpinLock,
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IN KIRQL OldIrql
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)
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{
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KeReleaseSpinLock ( pSpinLock, OldIrql ) ;
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AudioPerformYield();
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}
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void
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AudioObDereferenceObject(
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IN PVOID pvObject
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)
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{
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ObDereferenceObject(pvObject);
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AudioPerformYield();
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}
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void
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AudioIoCompleteRequest(
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IN PIRP pIrp,
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IN CCHAR PriorityBoost
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)
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{
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IoCompleteRequest(pIrp,PriorityBoost);
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AudioPerformYield();
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}
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#endif
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#define MEMORY_LIMIT_CHECK 262144
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//
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// This routine assumes that pptr points to a memory location that currently
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// contains a NULL value. Thus, on failure, this routine does not have to
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// write back a NULL value.
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//
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// Entry:
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// if dwFlags contains:
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//#define DEFAULT_MEMORY 0x00 // Standard ExAllocatePool call
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//#define ZERO_FILL_MEMORY 0x01 // Zero the memory
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//#define QUOTA_MEMORY 0x02 // ExAllocatePoolWithQuota call
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//#define LIMIT_MEMORY 0x04 // Never allocation more then 1/4 Meg
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//#define FIXED_MEMORY 0x08 // Use locked memory
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//#define PAGED_MEMORY 0x10 // use pageable memory
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//
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NTSTATUS
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AudioAllocateMemory(
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IN SIZE_T bytes,
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IN ULONG tag,
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IN AAMFLAGS dwFlags,
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OUT PVOID *pptr
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)
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{
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NTSTATUS Status;
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POOL_TYPE pooltype;
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PVOID pInit;
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KIRQL irql;
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PVOID ptr = NULL;
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ASSERT(*pptr == NULL);
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if( 0 == bytes )
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{
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//
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// The code should never be asking for zero bytes. The core will bugcheck
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// on a call like this. In debug mode we'll assert. In retail, we'll
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// return an error.
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//
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ASSERT(0);
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Status = STATUS_INSUFFICIENT_RESOURCES;
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} else {
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if( dwFlags & FIXED_MEMORY )
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pooltype = NonPagedPool;
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else
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pooltype = PagedPool;
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//
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// Allocating pageable memory at DISPATCH_LEVEL is a bad thing to do.
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// here we make sure that is not the case.
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//
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if( ( (irql = KeGetCurrentIrql()) > DISPATCH_LEVEL ) ||
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((DISPATCH_LEVEL == irql ) && (NonPagedPool != pooltype)) )
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{
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//
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// Either way, we've got an error, bugcheck or exit.
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//
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if( gbRobustChecking )
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{
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KeBugCheckEx(AUDIO_BUGCHECK_CODE,AUDIO_INVALID_IRQL_LEVEL,0,0,0);
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} else {
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//
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// If we can't bugcheck, then we're going to return an error
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// in this case.
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//
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Status = STATUS_INSUFFICIENT_RESOURCES;
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goto exit;
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}
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}
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//
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// Let's see if the caller has asked to limit the allocation to a "reasonable"
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// number of bytes. If so, "reasonable" is 1/4 meg.
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//
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if( ( dwFlags & LIMIT_MEMORY ) && ( bytes > MEMORY_LIMIT_CHECK ) )
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{
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//
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// For some reason, this allocation is trying to allocate more then was designed.
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// Why is the caller allocating so much?
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//
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if( gbRobustChecking )
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KeBugCheckEx(AUDIO_BUGCHECK_CODE,AUDIO_ABSURD_ALLOCATION_ATTEMPTED,0,0,0);
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//
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// Checked build will assert if robust checking is not enabled.
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//
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ASSERT("Memory Allocation Unreasonable!");
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}
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//
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// Allocate the memory, NULL is returned on failure in the normal case, an exception
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// is raised with quota. ptr is NULLed out above for the Quota routine.
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//
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if( dwFlags & QUOTA_MEMORY )
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{
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//
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// Caller wants to charge the allocation to the current user context.
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//
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try
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{
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ptr = ExAllocatePoolWithQuotaTag(pooltype,bytes,tag);
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}except (EXCEPTION_EXECUTE_HANDLER) {
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Status = STATUS_INSUFFICIENT_RESOURCES;
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}
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} else {
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//
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// Don't want to assign this memory to the quota.
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//
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ptr = ExAllocatePoolWithTag(pooltype, bytes, tag);
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}
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if( ptr )
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{
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if( dwFlags & ZERO_FILL_MEMORY )
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{
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RtlFillMemory( ptr,bytes,0 );
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}
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//
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// Never allocate over the top of an existing pointer. Interlock exchange
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// with the location. This interlock updates the location in the caller.
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//
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if( pInit = InterlockedExchangePointer(pptr,ptr) )
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{
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//
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// If we get a return value from this exchange it means that there
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// was already a pointer in the location that we added a pointer too.
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// If this is the case, most likely we overwrote a valid memory
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// pointer. With robust checking we don't want this to happen.
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//
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if( gbRobustChecking )
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{
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KeBugCheckEx(AUDIO_BUGCHECK_CODE,
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AUDIO_MEMORY_ALLOCATION_OVERWRITE,
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(ULONG_PTR)pInit,
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0,0);
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}
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//
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// If we end up here, we've overwritten a memory pointer with a
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// successful memory allocation. Or ASSERT at the top of this
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// function should have fired. In any case, we can return success
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// and how that nothing bad happens.
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//
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}
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Status = STATUS_SUCCESS;
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} else {
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//
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// Our memory allocation failed. *pptr should still be NULL
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// return error.
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//
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Status = STATUS_INSUFFICIENT_RESOURCES;
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}
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}
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exit:
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return Status;
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}
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//
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// This routine is safe to call with a NULL memory pointer. It will return
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// STATUS_UNSUCCESSFUL and do nothing if passed a NULL pointer. Also, this routine
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// reads the location atomically so it should be safe in a multiproc environment.
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//
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void
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AudioFreeMemory(
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IN SIZE_T bytes,
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IN OUT PVOID *pptr
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)
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{
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PVOID pFree;
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KIRQL irql;
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//
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// Interlockedexhchange the pointer will NULL, validate that it's non-NULL
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// trash the memory if needed and then free the pointer.
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//
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pFree = InterlockedExchangePointer(pptr,NULL);
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if( pFree )
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{
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//
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// We have a pointer to free.
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//
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if( gbRobustChecking )
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{
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//
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// The docs say that we need to be careful how we call the free routine
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// with regard to IRQlevel. Thus, if we're being robust we'll do this
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// extra work.
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//
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if( (irql = KeGetCurrentIrql()) > DISPATCH_LEVEL )
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{
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KeBugCheckEx(AUDIO_BUGCHECK_CODE,AUDIO_INVALID_IRQL_LEVEL,0,0,0);
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}
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//
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// Under debug we're going to put 'k's in the memory location in order
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// to make extra sure that no one is using this memory.
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//
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if( UNKNOWN_SIZE != bytes )
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{
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RtlFillMemory( pFree,bytes,'k' );
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}
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}
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//
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// Now we actually free the memory.
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//
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ExFreePool(pFree);
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}
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return;
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}
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