Re: unkillable process due to setup_frame() failure

[Ralf Baechle <ralf@linux-mips.org>]

On Wed, Sep 07, 2005 at 10:14:16AM +0100, Maciej W. Rozycki wrote:

> > > So, the process can not be kill by SIGKILL.  In 2.6.12, 'sigkill
> > > priority fix' was applied to __dequeue_signal(), but it does not help
> > > while the SIGTRAP is queued to tsk->pending but SIGKILL (by kill
> > > command) is queued to tsk->signal->shared_pending.
> > 
> > The behaviour of not advancing the EPC beyond the faulting instruction is
> > part of the problem - but I believe that was the usual behaviour for
> > MIPS UNIXoid operating systems.
> 
>  Well, SIGKILL should always work and frankly I can't see a reason to 
> return back to user space in the affected context in the first place.  
> What's left in EPC shouldn't matter.

I said it's part of the problem - not that it should be changed.  The
behaviour as far as I can say is also standard for MIPS unixoid operating
systems.  That said, I definately prefer the approach of Atushi's suggested
fix #2.  The other question is why we try to continue if delivering a
signal failed and we already know that repeated attempts would fail again.

  Ralf