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Date: Thu, 1 May 2008 11:42:28 -0500
From: Scott Wood <scottwood@freescale.com>
To: Kumar Gala <galak@kernel.crashing.org>
Subject: Re: [PATCH] [POWERPC] Rework EXC_LEVEL_EXCEPTION_PROLOG code
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On Thu, May 01, 2008 at 11:33:34AM -0500, Kumar Gala wrote:
> Let me ask the question differently.  Are there cases that some event  
> occurs in the system and a signal is delivered to the current process  
> regardless of what that process is.

Yes, timers that expire based on CPU usage.

>  I'm guessing so, based on the tty example.

I don't think tty interrupts would -- it'd go to the process group
associated with the tty.

> So for the specific case I'm looking at (kprobes & debug exceptions  
> from kernel space), I think its reasonable to BUG_ON() if thread_info- 
> >flags changes such that TIF_SIGPENDING or TIF_NEED_RESCHED get set  
> we aren't from user-space.

Why?  It may not happen currently, but it seems more future-proof to just
copy the flags.  And it's certainly not reasonable for normal interrupts.

-Scott