Re: [ros-dev] Re: [ros-svn] [weiden] 13138: implemented the ProcessSessionInformation information class

[Joseph Galbraith]

Hartmut Birr wrote:
>   weiden(a)svn.reactos.com schrieb:
>  
> >   implemented the ProcessSessionInformation
> > information class
> >
> >
> >  Updated files:
> >  trunk/reactos/ntoskrnl/ps/process.c 
>  
>  I think that some parts of your implementation are incorrect. The 
>  function must check for the location of the buffer and the previous 
>  mode. If the previous mode is user mode, the buffer must be located 
>  within the user address space. IMHO using of  MmCopyFrom/ToCaller is 
>  better than using an exception block. It is also true for your following 
>  commits. 
Do MmCopyFrom/ToCaller use SEH?

If not, both are necessary.  Using SEH protects from another
thread in the process (or some other component) free the VM
page and cause a crash.

So not only must the address be checked to make sure it
is a user mode address iff the caller is user mode, but
the parameter need to be copied using SEH; otherwise
what was just probed as valid may become invalid before
the copy can be done.

Thanks,

Joseph