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- Fix a crash that happens when we are running at APC_LEVEL, acquire the recursive mutex (which improperly handled APC_LEVEL), then attempt to access paged pool (or do anything else that depends on Irql < DISPATCH_LEVEL)

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- Optimize the code for acquiring and releasing the recursive mutex at DISPATCH_LEVEL

svn path=/trunk/; revision=41600
This commit is contained in:
Cameron Gutman
2009-06-24 21:57:48 +00:00
parent 5206a90897
commit 5d33bdc236
1 changed files with 14 additions and 10 deletions
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reactos/drivers/network/tcpip/recmutex/recmutex.c
+14 -10
View File
@@ -14,6 +14,7 @@ VOID RecursiveMutexInit( PRECURSIVE_MUTEX RecMutex ) {
SIZE_T RecursiveMutexEnter( PRECURSIVE_MUTEX RecMutex, BOOLEAN ToWrite ) {
NTSTATUS Status = STATUS_SUCCESS;
PVOID CurrentThread = KeGetCurrentThread();
KIRQL CurrentIrql;
/* Wait for the previous user to unlock the RecMutex state. There might be
* multiple waiters waiting to change the state. We need to check each
@@ -27,9 +28,13 @@ SIZE_T RecursiveMutexEnter( PRECURSIVE_MUTEX RecMutex, BOOLEAN ToWrite ) {
return TRUE;
}
if( KeGetCurrentIrql() == PASSIVE_LEVEL ) {
CurrentIrql = KeGetCurrentIrql();
ASSERT(CurrentIrql <= DISPATCH_LEVEL);
if( CurrentIrql <= APC_LEVEL ) {
ExAcquireFastMutex( &RecMutex->Mutex );
RecMutex->OldIrql = PASSIVE_LEVEL;
RecMutex->OldIrql = CurrentIrql;
while( RecMutex->Locked ) {
ExReleaseFastMutex( &RecMutex->Mutex );
Status = KeWaitForSingleObject( &RecMutex->StateLockedEvent,
@@ -45,7 +50,8 @@ SIZE_T RecursiveMutexEnter( PRECURSIVE_MUTEX RecMutex, BOOLEAN ToWrite ) {
RecMutex->LockCount++;
ExReleaseFastMutex( &RecMutex->Mutex );
} else {
KeAcquireSpinLock( &RecMutex->SpinLock, &RecMutex->OldIrql );
KeAcquireSpinLockAtDpcLevel( &RecMutex->SpinLock );
RecMutex->OldIrql = DISPATCH_LEVEL;
RecMutex->Locked = TRUE;
RecMutex->Writer = ToWrite;
RecMutex->CurrentThread = CurrentThread;
@@ -56,14 +62,13 @@ SIZE_T RecursiveMutexEnter( PRECURSIVE_MUTEX RecMutex, BOOLEAN ToWrite ) {
}
VOID RecursiveMutexLeave( PRECURSIVE_MUTEX RecMutex ) {
if( RecMutex->LockCount == 0 ) {
return;
} else
RecMutex->LockCount--;
ASSERT(RecMutex->LockCount > 0);
RecMutex->LockCount--;
if( !RecMutex->LockCount ) {
RecMutex->CurrentThread = NULL;
if( RecMutex->OldIrql == PASSIVE_LEVEL ) {
if( RecMutex->OldIrql <= APC_LEVEL ) {
ExAcquireFastMutex( &RecMutex->Mutex );
RecMutex->Locked = FALSE;
RecMutex->Writer = FALSE;
@@ -71,10 +76,9 @@ VOID RecursiveMutexLeave( PRECURSIVE_MUTEX RecMutex ) {
} else {
RecMutex->Locked = FALSE;
RecMutex->Writer = FALSE;
KeReleaseSpinLock( &RecMutex->SpinLock, RecMutex->OldIrql );
KeReleaseSpinLockFromDpcLevel( &RecMutex->SpinLock );
}
RecMutex->OldIrql = PASSIVE_LEVEL;
KePulseEvent( &RecMutex->StateLockedEvent, IO_NETWORK_INCREMENT,
FALSE );
}