RE: [Xen-devel] [PATCH][cpufreq] add bounds checking for getcpuidletime

["Langsdorf, Mark" <mark.langsdorf@xxxxxxx>]

16519 fixes my problem.  Thanks!

-Mark Langsdorf
Operating System Research Center
AMD 

> -----Original Message-----
> From: Keir Fraser [mailto:Keir.Fraser@xxxxxxxxxxxx] 
> Sent: Tuesday, December 04, 2007 5:54 AM
> To: Langsdorf, Mark; xen-devel@xxxxxxxxxxxxxxxxxxx
> Subject: Re: [Xen-devel] [PATCH][cpufreq] add bounds checking 
> for getcpuidletime
> 
> This is supposed to be handled by xenctl_cpumap_to_cpumask, 
> but it looks
> like it's buggy. I checked in a fix as changeset 16519. Can 
> you please try
> with that and see if it fixes your problem?
> 
>  -- Keir
> 
> On 3/12/07 16:48, "Mark Langsdorf" <mark.langsdorf@xxxxxxx> wrote:
> 
> > The Xen platform hypercall for getting the cpu idletime does not
> > check to make sure that all cpus in the map have indexes less
> > than the size of the array that it writes the data into.  Add
> > bounds checking to avoid memory corruption.
> > 
> > Signed-off-by: Mark Langsdorf <mark.langsdorf@xxxxxxx>
> > 
> > diff -r d40788f07a4f xen/arch/x86/platform_hypercall.c
> > --- a/xen/arch/x86/platform_hypercall.c Sun Nov 25 12:43:13 
> 2007 +0000
> > +++ b/xen/arch/x86/platform_hypercall.c Mon Dec 03 10:25:23 
> 2007 -0600
> > @@ -326,6 +326,9 @@ ret_t do_platform_op(XEN_GUEST_HANDLE(xe
> >                  cpu_clear(cpu, cpumap);
> >              }
> >  
> > +            if (cpu >= ctlmap.nr_cpus)
> > +                continue;
> > +
> >              ret = -EFAULT;
> >              if ( copy_to_guest_offset(idletimes, cpu, 
> &idletime, 1) )
> >                  goto out;
> > 
> > 
> > 
> > _______________________________________________
> > Xen-devel mailing list
> > Xen-devel@xxxxxxxxxxxxxxxxxxx
> > http://lists.xensource.com/xen-devel
> 
> 
> 
> 
> 



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