Project Home
Project Home		 Documents
Documents		 Wiki
Wiki		 Discussion Forums
Discussions		 Project Information
Project Info
QNX Operating System/Discussion/OSTech/InterruptDetach and EPERM/List of Posts
Forum Topic - InterruptDetach and EPERM: (3 Items)
   
Update
Andrew Sherk
07/23/2009 4:31 PM
post34464
InterruptDetach and EPERM   
Hi,

I have a test program that takes the interrupt id returned from another process' InterruptAttach and tries 
InterruptDetach with it.

EPERM is returned by InterruptDetach.

In the docs, 
"EPERM The process doesn't have superuser capabilities. "

Can I use an InterruptDetach from a different process? It is allowed? 
If it is not allowed, should the docs note this other reason for an EPERM?

From errno.h,
#define EPERM            1  /* Not owner                                */

ThreadCtl(_NTO_TCTL_IO, 0) returns ok and I can successfully InterruptMask and InterruptUnmask with this same id in my 
test program.

 _NTO_INTR_FLAGS_TRK_MSK | _NTO_INTR_FLAGS_END | _NTO_INTR_FLAGS_PROCESS are passed to InterruptAttach by the first 
process.

thanks,
asherk
David Sarrazin
07/23/2009 5:00 PM
post34465
RE: InterruptDetach and EPERM   
 

> -----Original Message-----
> From: Andrew Sherk [mailto:community-noreply@qnx.com] 
> Sent: July 23, 2009 4:31 PM
> To: ostech-core_os
> Subject: InterruptDetach and EPERM
> 
> Hi,
> 
> I have a test program that takes the interrupt id returned 
> from another process' InterruptAttach and tries 
> InterruptDetach with it.
> 
> EPERM is returned by InterruptDetach.
> 
> In the docs,
> "EPERM The process doesn't have superuser capabilities. "
> 
> Can I use an InterruptDetach from a different process? It is allowed? 


There's a check in the detach code that makes sure the thread calling
InterruptDetach() belongs to the same process as the thread that called
InterruptAttach().  If that check fails, it returns EPERM.


> If it is not allowed, should the docs note this other reason 
> for an EPERM?

Probably.  Maybe something like this?

EPERM
	The process doesn't have superuser privelages or is not the
process that attached the interrupt identified by _id_.

> 
> thanks,
> asherk
> 
> 
> 
> _______________________________________________
> 
> OSTech
> http://community.qnx.com/sf/go/post34464
> 
>
Andrew Sherk
08/19/2009 3:16 PM
post36324
RE: InterruptDetach and EPERM   
Thanks, Dave, for your feedback.
PR 70642 has been opened.

> > I have a test program that takes the interrupt id returned from 
> > another process' InterruptAttach and tries InterruptDetach with it.
> > 
> > EPERM is returned by InterruptDetach.
> > 
> > In the docs,
> > "EPERM The process doesn't have superuser capabilities. "
> > 
> > Can I use an InterruptDetach from a different process? It 
> is allowed? 
> 
> 
> There's a check in the detach code that makes sure the thread calling
> InterruptDetach() belongs to the same process as the thread 
> that called InterruptAttach().  If that check fails, it returns EPERM.
> 
> 
> > If it is not allowed, should the docs note this other reason for an 
> > EPERM?
> 
> Probably.  Maybe something like this?
> 
> EPERM
> 	The process doesn't have superuser privelages or is not 
> the process that attached the interrupt identified by _id_.

Return


  A subsidiary of BlackBerry             All content ©2004-2013, QNX Software Systems