Re: [PATCH] Check CPL for break 0x80001 case. Re: [Xen-ia64-devel] [Q]ltrace and do_ssc

[Isaku Yamahata <yamahata@xxxxxxxxxxxxx>]

This patch is incomplete.
If the guest kernel issues break 0x80001 or 0x80002 with
an unknown SSC command, xen shouldn't fall in infinit loop.
It should panic domain (not xen) or return error.

On Wed, Nov 29, 2006 at 08:07:36PM +0900, Atsushi SAKAI wrote:
> Hi, All
> 
>  This is a patch which intends for fixing ltrace problem.
> When I execute a command "ltrace ps" on dom0, it makes dom0 hung.
> It comes from "break 0x80001" is shared by ltrace(CPL=3) and hpsim(CPL=2).
> To avoid this problem, I just add check CPL in ia64_break_fault code.
> 
> References
> Yamahata mail
> http://lists.xensource.com/archives/html/xen-ia64-devel/2006-11/msg00319.html
> Alex mail
> http://lists.xensource.com/archives/html/xen-ia64-devel/2006-11/msg00318.html
> 
> Signed-off-by: Atsushi SAKAI <sakaia@xxxxxxxxxxxxxx>
> 
> 
> Thanks
> Atsushi SAKAI
> 
> 
> 
> 
> >Hi, Alex
> >
> >Thank you for your comments
> >With this following fixes it seems running.
> >
> >
> >Thanks
> >Atsushi SAKAI
> >
> >>On Wed, 2006-11-29 at 11:27 +0900, Atsushi SAKAI wrote:
> >>> Hi, Alex
> >>>
> >>>   I am trying "ltrace ps" on IA64.
> >>> It makes dom0 hung.
> >>>
> >>> >From the serial console messages,
> >>> (XEN) ia64_handle_break: bad ssc code 400000000001c480, 
> >>> iip=0x4000000000002140,
> >>> b0=0x4000000000002380... spinning
> >>>
> >>> It seems come from following system call.
> >>>
> >>> ia64_ssc@xxxxxxxxxxxxxxxxxxx/arch/ia64/hp/sim/hpsim.S
> >>>
> >>>
> >>> Do you have any idea to solve this problem?
> >>
> >>   I'd guess you happened to hit a break value that overlaps with the
> >>ones chosen for trapping into ski.  You might try getting rid of the
> >>first test in handle_break() that calls do_ssc().
> >>
> >>    Alex
> >>
> >>--
> >>Alex Williamson                             HP Open Source & Linux Org.
> >>
> >>
> >
> >
> >
> >
> >
> 
> >_______________________________________________
> >Xen-ia64-devel mailing list
> >Xen-ia64-devel@xxxxxxxxxxxxxxxxxxx
> >http://lists.xensource.com/xen-ia64-devel
> 
> 
> 
> 
> 
> 


> _______________________________________________
> Xen-ia64-devel mailing list
> Xen-ia64-devel@xxxxxxxxxxxxxxxxxxx
> http://lists.xensource.com/xen-ia64-devel

-- 
yamahata

_______________________________________________
Xen-ia64-devel mailing list
Xen-ia64-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-ia64-devel