我正在为 Windows 7 32 位编写设备驱动程序。我正在使用 WDK 版本 7600.16385.1。到目前为止一切进展顺利，但 prefast 一直告诉我我搞砸了 IRQL 级别。特别是当我尝试锁定/解锁共享缓冲区时。
我有一个表示缓冲区的结构，如下所示：
typedef struct _PORT_BUFFER {
WDFMEMORY mMemory;
PUCHAR pucBuff;
ULONG ulSizeMax;
ULONG ulSizeCurr;
ULONG ulAdd;
ULONG ulRemove;
ULONG ulLost;
WDFREQUEST rPending;
BOOLEAN bDMAing;
WDFSPINLOCK slLock;
} PORT_BUFFER, *PPORT_BUFFER;
我有两个功能可以锁定和解锁所述缓冲区：
VOID PLxBufferLock(PPORT_BUFFER ppbBuff){
WdfSpinLockAcquire(ppbBuff->slLock);
}
VOID PLxBufferUnlock(PPORT_BUFFER ppbBuff){
WdfSpinLockRelease(ppbBuff->slLock);
}
当我编译我的驱动程序时，prefast 告诉我：
warning 28167 : The function 'PLxBufferLock' changes the IRQL and does not restore the IRQL before it exits. It should be annotated to reflect the change or the IRQL should be restored. IRQL was last set to 2 at line 57.
warning 28167 : The function 'PLxBufferUnlock' changes the IRQL and does not restore the IRQL before it exits. It should be annotated to reflect the change or the IRQL should be restored. IRQL was last set at line 63.
因此，我查看了 WdfSpinLockAcquire 和 WdfSpinLockRelease 是如何定义的：
__drv_raisesIRQL(DISPATCH_LEVEL)
__drv_maxIRQL(DISPATCH_LEVEL)
VOID
FORCEINLINE
WdfSpinLockAcquire(
__in
__drv_savesIRQL
__drv_neverHold(SpinLockObj)
__drv_acquiresResource(SpinLockObj)
WDFSPINLOCK SpinLock
)
{
((PFN_WDFSPINLOCKACQUIRE) WdfFunctions[WdfSpinLockAcquireTableIndex])(WdfDriverGlobals, SpinLock);
}
__drv_maxIRQL(DISPATCH_LEVEL)
__drv_minIRQL(DISPATCH_LEVEL)
VOID
FORCEINLINE
WdfSpinLockRelease(
__in
__drv_restoresIRQL
__drv_mustHold(SpinLockObj)
__drv_releasesResource(SpinLockObj)
WDFSPINLOCK SpinLock
)
{
((PFN_WDFSPINLOCKRELEASE) WdfFunctions[WdfSpinLockReleaseTableIndex])(WdfDriverGlobals, SpinLock);
}
看起来很简单。所以我改变了我的功能看起来一样：
__drv_raisesIRQL(DISPATCH_LEVEL)
__drv_maxIRQL(DISPATCH_LEVEL)
VOID PLxBufferLock(
__in
__drv_savesIRQL
__drv_neverHold(ppbBuff)
__drv_acquiresResource(ppbBuff)
PPORT_BUFFER ppbBuff);
__drv_maxIRQL(DISPATCH_LEVEL)
__drv_minIRQL(DISPATCH_LEVEL)
VOID PLxBufferUnlock(
__in
__drv_restoresIRQL
__drv_mustHold(ppbBuff)
__drv_releasesResource(ppbBuff)
PPORT_BUFFER ppbBuff);
然后我从两个警告变成了许多关于泄漏 ppbBuff 并且仍然没有正确恢复 IRQL 级别的警告：
warning 28103 : Leaking the ppbBuff stored in 'ppbBuff'.
warning 28104 : The ppbBuff that should have been acquired before function exit was not acquired.
warning 28107 : The ppbBuff '&pdepPort->pbRead' must be held when calling 'PLxBufferUnlock'.
warning 28107 : The ppbBuff '&pdepPort->pbWrite' must be held when calling 'PLxBufferUnlock'.
warning 28107 : The ppbBuff '&pdepExtPort->pbRead' must be held when calling 'PLxBufferUnlock'.
warning 28107 : The ppbBuff '&pdepExtPort->pbRead' must be held when calling 'PLxBufferUnlock'.
warning 28107 : The ppbBuff '&pdepExtPort->pbWrite' must be held when calling 'PLxBufferUnlock'.
warning 28157 : The IRQL in 'ppbBuff' was never restored.
warning 28158 : No IRQL was saved into 'ppbBuff'.
warning 28166 : The function 'PLxInitEvtPortCleanup' does not restore the IRQL to the value that was current at function entry and is required to do so. IRQL was last set at line 320.
warning 28166 : The function 'PLxReadEvt' does not restore the IRQL to the value that was current at function entry and is required to do so. IRQL was last set at line 51.
warning 28166 : The function 'PLxReadEvtTimer' does not restore the IRQL to the value that was current at function entry and is required to do so. IRQL was last set at line 104.
warning 28166 : The function 'PLxWriteEvt' does not restore the IRQL to the value that was current at function entry and is required to do so. IRQL was last set at line 60.
我使用缓冲区，我没有在任何地方检查错误，所以我认为我锁定正确。任何人都知道如何在这种情况下安抚prefast？谢谢！
编辑：
这是我使用锁定功能的示例：
VOID PLxInitEvtPortCleanup(WDFFILEOBJECT foFileObject){
PDEVICE_EXTENSION_PORT pdepPort = NULL;
PDEVICE_EXTENSION_CARD pdecCard = NULL;
GSCSIO4BXSYNC_PORT_CONFIGURATION pcPortConfig = { 0 };
WDFREQUEST rRequest = NULL;
pdepPort = PLxGetDeviceContextPort(WdfFileObjectGetDevice(foFileObject));
pdecCard = PLxGetDeviceContextCard(pdepPort->dDeviceCard);
pcPortConfig.bEnable = FALSE;
pcPortConfig.bRxEnable = FALSE;
pcPortConfig.bTxEnable = FALSE;
pcPortConfig.ulClockFrequency = 0;
pcPortConfig.eptcdTxClockDirection = GSCSIO4BXSYNC_ESTCD_INPUT;
PLxSioConfigPortSet(pdecCard,pdepPort->ulPortNumber,&pcPortConfig);
PLxBufferLock(&pdepPort->pbRead);
rRequest = PLxBufferClearPendingRequest(&pdepPort->pbRead);
PLxBufferUnlock(&pdepPort->pbRead);
if (rRequest) WdfRequestComplete(rRequest,STATUS_CANCELLED);
PLxBufferLock(&pdepPort->pbWrite);
rRequest = PLxBufferClearPendingRequest(&pdepPort->pbWrite);
PLxBufferUnlock(&pdepPort->pbWrite);
if (rRequest) WdfRequestComplete(rRequest,STATUS_CANCELLED);
}
我锁定缓冲区，删除任何挂起的请求，解锁缓冲区并完成请求。Prefast 告诉我我没有正确恢复 IRQL 级别。当我注释掉锁定/清除/解锁/完成代码时，prefast 又高兴了。
编辑：
我已经升级到VS2015和WDK10+SDK10。我添加了 M'hand BOUGHIAS 建议的注释：
_Acquires_lock_(ppbBuff->slLock)
_Requires_lock_not_held_(ppbBuff->slLock)
_IRQL_saves_
VOID PLxBufferLock(PPORT_BUFFER ppbBuff){
WdfSpinLockAcquire(ppbBuff->slLock);
}
_Releases_lock_(ppbBuff->slLock)
_Requires_lock_held_(ppbBuff->slLock)
_IRQL_restores_
VOID PLxBufferUnlock(PPORT_BUFFER ppbBuff){
WdfSpinLockRelease(ppbBuff->slLock);
}
现在我得到以下信息：
warning C28158: No IRQL was saved into 'return'.
warning C28167: The function 'PLxBufferLock' changes the IRQL and does not restore the IRQL before it exits. It should be annotated to reflect the change or the IRQL should be restored.
warning C28157: The IRQL in 'return' was never restored.
我注意到 _Acquires_lock_ 和 _Requires_lock_not_held_ 定义为空，所以我查看了它们并注意到它们需要定义 _PREFAST_ 才能工作。所以我将 _PREFAST_ 添加到我的预处理器定义中。现在我得到了一堆链接错误，但没有更多的 prefast 错误！
error LNK2005: __Lock_kind_mutex_ already defined in Buffer.obj
error LNK2005: __Lock_kind_event_ already defined in Buffer.obj
error LNK2005: __Lock_kind_semaphore_ already defined in Buffer.obj
error LNK2005: __Lock_kind_spin_lock_ already defined in Buffer.obj
error LNK2005: __Lock_kind_critical_section_ already defined in Buffer.obj
error LNK2001: unresolved external symbol __Prefast_unreferenced_parameter_impl_
我想我在将项目转换为 VS2015 时搞砸了。所以我创建了标准的 KMDF 驱动程序项目，它为您提供了一个很好的构建框架。我在新项目中打开了静态分析并像以前一样定义了_PREFAST_，它也给了我同样的链接错误。