On Wed 25-01-17 12:15:59, Vlastimil Babka wrote:
> On 01/24/2017 04:00 PM, Michal Hocko wrote:
> > > > Well, I am not opposed to kvmalloc_array but I would argue that this
> > > > conversion cannot introduce new overflow issues. The code would have
> > > > to be broken already because even though kmalloc_array checks for the
> > > > overflow but vmalloc fallback doesn't...
> > >
> > > Yeah I agree, but if some of the places were really wrong, after the
> > > conversion we won't see them anymore.
> > >
> > > > If there is a general interest for this API I can add it.
> > >
> > > I think it would be better, yes.
> >
> > OK, fair enough. I will fold the following into the original patch. I
> > was little bit reluctant to create kvcalloc so I've made the original
> > callers more talkative and added | __GFP_ZERO.
>
> Fair enough,
>
> > To be honest I do not
> > really like how kcalloc...
>
> how kcalloc what?
how kcalloc hides the GFP_ZERO and the name doesn't reflect that.
> [...]
> > diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c
> > index cdc55d5ee4ad..eca16612b1ae 100644
> > --- a/net/netfilter/x_tables.c
> > +++ b/net/netfilter/x_tables.c
> > @@ -712,10 +712,7 @@ EXPORT_SYMBOL(xt_check_entry_offsets);
> > */
> > unsigned int *xt_alloc_entry_offsets(unsigned int size)
> > {
> > - if (size < (SIZE_MAX / sizeof(unsigned int)))
> > - return kvzalloc(size * sizeof(unsigned int), GFP_KERNEL);
> > -
> > - return NULL;
> > + return kvmalloc_array(size * sizeof(unsigned int), GFP_KERNEL |
> > __GFP_ZERO);
>
> This one wouldn't compile.
fixed, thanks!
--
Michal Hocko
SUSE Labs
