From: Michal Hocko <mhocko@kernel.org>
To: Christoph Lameter <cl@linux.com>
Cc: Kees Cook <keescook@chromium.org>,
Andrew Morton <akpm@linux-foundation.org>,
Pekka Enberg <penberg@kernel.org>,
David Rientjes <rientjes@google.com>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>,
Linux-MM <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] mm: Add additional consistency check
Date: Tue, 11 Apr 2017 18:41:36 +0200 [thread overview]
Message-ID: <20170411164134.GA21171@dhcp22.suse.cz> (raw)
In-Reply-To: <alpine.DEB.2.20.1704111110130.24725@east.gentwo.org>
On Tue 11-04-17 11:16:42, Cristopher Lameter wrote:
> On Tue, 11 Apr 2017, Michal Hocko wrote:
>
> > static inline void *index_to_obj(struct kmem_cache *cache, struct page *page,
> > @@ -3813,14 +3818,18 @@ void kfree(const void *objp)
> > {
> > struct kmem_cache *c;
> > unsigned long flags;
> > + struct page *page;
> >
> > trace_kfree(_RET_IP_, objp);
> >
> > if (unlikely(ZERO_OR_NULL_PTR(objp)))
> > return;
> > + page = virt_to_head_page(obj);
> > + if (CHECK_DATA_CORRUPTION(!PageSlab(page)))
>
> There is a flag SLAB_DEBUG_OBJECTS that is available for this check.
Which is way too late, at least for the kfree path. page->slab_cache
on anything else than PageSlab is just a garbage. And my understanding
of the patch objective is to stop those from happening.
> Consistency checks are configuraable in the slab allocator.
and they have to be compiled in (at least for SLAB) AFAIR.
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2017-04-11 16:41 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-31 16:40 [PATCH] mm: Add additional consistency check Kees Cook
2017-03-31 21:33 ` Andrew Morton
2017-04-01 0:04 ` Kees Cook
2017-04-03 3:40 ` Michael Ellerman
2017-04-03 14:03 ` Christoph Lameter
2017-04-03 14:53 ` Matthew Wilcox
2017-04-04 11:30 ` Michal Hocko
2017-04-04 15:07 ` Christoph Lameter
2017-04-04 15:16 ` Michal Hocko
2017-04-04 15:46 ` Kees Cook
2017-04-04 15:58 ` Michal Hocko
2017-04-04 16:02 ` Kees Cook
2017-04-04 19:13 ` Christoph Lameter
2017-04-04 19:42 ` Michal Hocko
2017-04-04 19:58 ` Christoph Lameter
2017-04-04 20:13 ` Michal Hocko
2017-04-11 4:58 ` Kees Cook
2017-04-11 13:46 ` Michal Hocko
2017-04-11 14:14 ` Kees Cook
2017-04-11 14:19 ` Michal Hocko
2017-04-11 16:05 ` Kees Cook
2017-04-11 16:16 ` Christoph Lameter
2017-04-11 16:19 ` Kees Cook
2017-04-11 16:23 ` Christoph Lameter
2017-04-11 16:30 ` Kees Cook
2017-04-11 16:26 ` Christoph Lameter
2017-04-11 16:41 ` Michal Hocko [this message]
2017-04-11 18:03 ` Christoph Lameter
2017-04-11 18:30 ` Michal Hocko
2017-04-11 18:44 ` Christoph Lameter
2017-04-11 18:55 ` Michal Hocko
2017-04-11 18:59 ` Christoph Lameter
2017-04-11 19:39 ` Michal Hocko
2017-04-17 15:22 ` Christoph Lameter
2017-04-18 6:41 ` Michal Hocko
2017-04-18 13:31 ` Christoph Lameter
2017-04-18 13:37 ` Christoph Lameter
2017-04-28 1:11 ` Kees Cook
2017-04-28 6:16 ` Michal Hocko
2017-04-27 12:06 ` Michal Hocko
2017-04-11 18:30 ` Christoph Lameter
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