Write is sometimes called from the System process

[GoogleCodeExporter]

The driver's write function must be called within the context of the writing 
process, because only then we're able to collect information about the writer. 
However, write is sometimes called from a system worker thread (PID 4).

We need to find out why this happens and how to avoid it. Alternatively, we 
might be able to find the writing process even in that situation.

Original issue reported on code.google.com by sebastian.poeplau on 29 Jun 2012 at 9:11

[GoogleCodeExporter]

If a process keeps an open handle to the device and waits for some device 
control operation to complete, write calls from the system pseudo-process seem 
to occur more often.

There is no guarantee that our code is called in the originating process's 
context, so we should find a way to find the originator even if we're called in 
system context.

Original comment by sebastian.poeplau on 7 Aug 2012 at 9:15

[GoogleCodeExporter]

We might be able to intercept a *create* from the original process and later 
correlate it to the write attempt.

Original comment by sebastian.poeplau on 29 Oct 2012 at 10:50