WDK 6001: PREfast bug

Here is it. KeReleaseSpinLock was added temporarily to try to get rid of
PREfast warning. Unfortunately, this does not help, and a valid sequence of 2
MS's functions causes a warning:

// !!!
713 KeReleaseSpinLock(&(Disk->SpinLock), Irql);
714 IoCompleteRequest(Irp, IO_NO_INCREMENT);

vsnap.c(714) : warning 28192: No resource of the class 'SpinLock'
can be held when this function is called. 'Disk->SpinLock' is currently held.

 

If you know that the PREfast warning is false positive, why do you add
code that actually effects execution?

I would think that using a Nonmemory Resource Annotation is
preferrable in such case. For example, can you use
__drv_releasesResource or __drv_releasesResourceGlobal here?

http://msdn2.microsoft.com/en-us/library/cc264096.aspx

Unless, of course, I misunderstood what you wrote.

Don

 

If you know that the PREfast warning is false positive, why do you add

KeReleaseSpinLock marked by !!! was _surely_ never intended to be executed, I
added it _for 3 minutes_ only to test PREfast. Such a binary will never be
executed.

The actual code is:

KeAcquireSpinLock
call to my function which releases the spinlock within (and UnlockIrql is
passed via parameter), the function is properly annotated and is also used in
several other places, where all is fine
IoCompleteRequest

This offended PREfast, so I added - just to check PREfast - the
KeReleaseSpinLock call just before IoCompleteRequest. Yes, a false positive.

The "my function" mentioned above surely has __drv_releasesResource(SpinLock)
and this worked in other places it is used.

 

annotate the function which releases the lock to indicate the lock is being
released in this subfunction and pfd should be happy

d