Re: [PATCH] mm: Add additional consistency check

[Michal Hocko]

On Mon 17-04-17 10:22:29, Cristopher Lameter wrote:
> On Tue, 11 Apr 2017, Michal Hocko wrote:
> 
> > On Tue 11-04-17 13:59:44, Cristopher Lameter wrote:
> > > On Tue, 11 Apr 2017, Michal Hocko wrote:
> > >
> > > > I didn't say anything like that. Hence the proposed patch which still
> > > > needs some more thinking and evaluation.
> > >
> > > This patch does not even affect kfree().
> >
> > Ehm? Are we even talking about the same thing? The whole discussion was
> > to catch invalid pointers to _kfree_ and why BUG* is not the best way to
> > handle that.
> 
> The patch does not do that. See my review. Invalid points to kfree are
> already caught with a bug on. See kfree in mm/slub.c

Are you even reading those emails? First of all we are talking about
slab here. Secondly I've already pointed out that the BUG_ON(!PageSlab)
in kmem_freepages is already too late because we do operate on a
potential garbage from invalid page...
-- 
Michal Hocko
SUSE Labs