Prefast注释以修复IRQL级警告

时间：2016-05-17 02:36:46

标签： c windows driver prefast

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。到目前为止事情进展顺利，但prefast一直告诉我，我搞乱了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：

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;

我有两个可以锁定和解锁所述缓冲区的函数：

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.

所以，我看了如何定义WdfSpinLockAcquire和WdfSpinLockRelease：

__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);
}

似乎非常直截了当。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);

然后我从两个警告转到许多关于泄漏ppbBuff的警告，仍然没有正确恢复IRQL级别：

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，我不是在任何地方进行错误检查，所以我认为我正确锁定。在这种情况下，任何人都知道如何安抚prefast吗？谢谢！

编辑：

以下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，删除任何待处理请求，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/完整代码时，prefast再次开心。

编辑：

我已升级到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);

}

现在我得到以下内容：

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_被定义为什么都没有，所以我看了他们，发现他们需要定义_PREFAST_才能工作。所以我将_PREFAST_添加到我的预处理器定义中。现在我收到了一堆链接错误，但没有更多的快速错误！

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_

我认为在将项目转换为VS2015时我搞砸了。所以我创建了标准的KMDF驱动程序项目，为您提供了一个很好的构建框架。我在新项目中启用了静态分析，并像以前一样定义了_PREFAST_，它也给了我相同的链接错误。

1 个答案:

答案 0 :(得分：4)

你走的是好路。 实际上，由于SAL注释，您可以告诉prefast您的函数锁定或解锁对象： Annotating Locking Behavior

您还需要告诉prefast有关IRQL的更改： IRQL annotations for drivers

以下是根据您的代码使用SAL注释的示例代码，它们可能与旧的WDK7不同：

_IRQL_raises_(DISPATCH_LEVEL)
_Acquires_lock_(ppbBuff->slLock)  
_Requires_lock_not_held_(ppbBuff->slLock)
VOID PLxBufferLock(_In_ _IRQL_saves_ PPORT_BUFFER ppbBuff){
        WdfSpinLockAcquire(ppbBuff->slLock);    
}

_Releases_lock_(ppbBuff->slLock)
_Requires_lock_held_(ppbBuff->slLock)
VOID PLxBufferUnlock(_In_ _IRQL_restores_ PPORT_BUFFER ppbBuff){
    WdfSpinLockRelease(ppbBuff->slLock);
}

备注：您应该使用ppbBuff->slLock变量上的注释，而不是其所有者。

UPDATE：阅读完上述文档后，我更新了注释的使用，_IRQL_saves_/_IRQL_restores_必须用于函数参数而不是函数。您可能还需要使用_IRQL_raises_。我编辑了上面的代码示例。您还可以删除_PREFAST_定义以避免链接问题。 _PREFAST_由编译器在开始分析时定义。

更新2 ：您可以在函数上使用_IRQL_saves_/_IRQL_restores注释，而不是在_In_参数上使用_IRQL_saves_global_(kind, param) / _IRQL_restores_global_(kind, param)注释。这是一个更新的代码示例：

_IRQL_raises_(DISPATCH_LEVEL)
_Acquires_lock_(ppbBuff->slLock)  
_Requires_lock_not_held_(ppbBuff->slLock)
_IRQL_saves_global_(SpinLock, ppbBuff)
VOID PLxBufferLock(_In_ PPORT_BUFFER ppbBuff){
        WdfSpinLockAcquire(ppbBuff->slLock);    
}

_Releases_lock_(ppbBuff->slLock)
_Requires_lock_held_(ppbBuff->slLock)
_IRQL_restores_global_(SpinLock, ppbBuff)
VOID PLxBufferUnlock(_In_ PPORT_BUFFER ppbBuff){
    WdfSpinLockRelease(ppbBuff->slLock);
}
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