Hesham/wintun
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Use synchronize_rcu()-like semantics for exclusive transition lock

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Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
This commit is contained in:
Jason A. Donenfeld 2019-06-27 09:59:22 +00:00
parent 33cac1114c
commit 248d4268df
1 changed files with 12 additions and 8 deletions
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20
wintun.c
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@ -986,10 +986,11 @@ static void
TunDispatchClose(_Inout_ TUN_CTX *Ctx, _Inout_ IRP *Irp)
{
IO_STACK_LOCATION *stack = IoGetCurrentIrpStackLocation(Irp);
KIRQL irql = ExAcquireSpinLockExclusive(&Ctx->TransitionLock);
ASSERT(InterlockedGet64(&Ctx->Device.RefCount) > 0);
BOOLEAN last_handle = InterlockedDecrement64(&Ctx->Device.RefCount) <= 0;
ExReleaseSpinLockExclusive(&Ctx->TransitionLock, irql);
ExReleaseSpinLockExclusive(
&Ctx->TransitionLock,
ExAcquireSpinLockExclusive(&Ctx->TransitionLock)); // Ensure above change is visible to all readers.
if (last_handle)
{
NDIS_HANDLE handle = InterlockedGetPointer(&Ctx->MiniportAdapterHandle);
@ -1073,9 +1074,10 @@ TunDispatchPnP(DEVICE_OBJECT *DeviceObject, IRP *Irp)
{
case IRP_MN_QUERY_REMOVE_DEVICE:
case IRP_MN_SURPRISE_REMOVAL: {
KIRQL irql = ExAcquireSpinLockExclusive(&ctx->TransitionLock);
InterlockedAnd(&ctx->Flags, ~TUN_FLAGS_PRESENT);
ExReleaseSpinLockExclusive(&ctx->TransitionLock, irql);
ExReleaseSpinLockExclusive(
&ctx->TransitionLock,
ExAcquireSpinLockExclusive(&ctx->TransitionLock)); // Ensure above change is visible to all readers.
TunQueueClear(ctx, NDIS_STATUS_ADAPTER_REMOVED);
break;
}
@ -1109,9 +1111,10 @@ TunPause(NDIS_HANDLE MiniportAdapterContext, PNDIS_MINIPORT_PAUSE_PARAMETERS Min
{
TUN_CTX *ctx = (TUN_CTX *)MiniportAdapterContext;
KIRQL irql = ExAcquireSpinLockExclusive(&ctx->TransitionLock);
InterlockedAnd(&ctx->Flags, ~TUN_FLAGS_RUNNING);
ExReleaseSpinLockExclusive(&ctx->TransitionLock, irql);
ExReleaseSpinLockExclusive(
&ctx->TransitionLock,
ExAcquireSpinLockExclusive(&ctx->TransitionLock)); // Ensure above change is visible to all readers.
TunQueueClear(ctx, NDIS_STATUS_PAUSED);
return TunCompletePause(ctx, FALSE);
@ -1468,9 +1471,10 @@ TunHaltEx(NDIS_HANDLE MiniportAdapterContext, NDIS_HALT_ACTION HaltAction)
ASSERT(!InterlockedGet64(&ctx->ActiveNBLCount)); // Adapter should not be halted if there are (potential)
// active NBLs present.
KIRQL irql = ExAcquireSpinLockExclusive(&ctx->TransitionLock);
InterlockedAnd(&ctx->Flags, ~TUN_FLAGS_PRESENT);
ExReleaseSpinLockExclusive(&ctx->TransitionLock, irql);
ExReleaseSpinLockExclusive(
&ctx->TransitionLock,
ExAcquireSpinLockExclusive(&ctx->TransitionLock)); // Ensure above change is visible to all readers.
for (IRP *pending_irp; (pending_irp = IoCsqRemoveNextIrp(&ctx->Device.ReadQueue.Csq, NULL)) != NULL;)
TunCompleteRequest(ctx, pending_irp, STATUS_FILE_FORCED_CLOSED, IO_NO_INCREMENT);