Re: [Qemu-devel] [PATCH] vl.c: Check -smp option ranges before setting int globals

[Eduardo Habkost]

On Fri, Jun 06, 2014 at 08:06:52AM +0200, Markus Armbruster wrote:
> Eduardo Habkost <address@hidden> writes:
> 
> > When parsing the -smp option, check if the values (that can be anywhere
> > in the [0, UINT64_MAX] range) are in the int range before setting the
> > int globals smp_cpus, max_cpus, smp_cores, smp_threads.
> >
> > Without this, it was posbible to make smp_cpus and max_cpus negative.
> >
> > Signed-off-by: Eduardo Habkost <address@hidden>
> 
> The INT_MAX limit might be too generous, but your code sure beats the
> silent truncation we have now.
> 

We will enforce other less generous limits (i.e. machine->max_cpus,
MAX_CPUMASK_BITS) later, outside smp_parse(), on the machine
initialization code.

These new checks are just to make sure smp_parse() won't silently
truncate the values when setting the globals (which is impossible to
check outside smp_parse()).

> Reviewed-by: Markus Armbruster <address@hidden>

Thanks!

-- 
Eduardo