Re: lockdep and kmemcheck

[Peter Zijlstra <peterz@infradead.org>]

On Thu, 2012-06-07 at 21:33 +0200, Borislav Petkov wrote:
> > WARNING: at kernel/lockdep.c:2739 lockdep_trace_alloc+0xcd/0xd0()
> > Hardware name: To be filled by O.E.M.
> > Modules linked in:
> > Pid: 1, comm: swapper/0 Not tainted 3.5.0-rc1 #3
> > Call Trace:
> >  [<ffffffff8104123a>] warn_slowpath_common+0x7a/0xb0
> >  [<ffffffff81041285>] warn_slowpath_null+0x15/0x20
> >  [<ffffffff81096f2d>] lockdep_trace_alloc+0xcd/0xd0
> >  [<ffffffff810ee48e>] __alloc_pages_nodemask+0x7e/0x890
> >  [<ffffffff810ee599>] ? __alloc_pages_nodemask+0x189/0x890
> >  [<ffffffff81278f3d>] ? trace_hardirqs_off_thunk+0x3a/0x3c
> >  [<ffffffff81278f3d>] ? trace_hardirqs_off_thunk+0x3a/0x3c
> >  [<ffffffff815c07d0>] ? error_exit+0x30/0xb0
> >  [<ffffffff811260c9>] kmemcheck_alloc_shadow+0x29/0xb0
> >  [<ffffffff8112409a>] new_slab+0x1fa/0x2e0
> >  [<ffffffff815b70ec>] __slab_alloc.isra.51.constprop.55+0x3e8/0x40e
> >  [<ffffffff815c07d0>] ? error_exit+0x30/0xb0
> >  [<ffffffff811251f7>] kmem_cache_alloc+0x87/0xb0
> >  [<ffffffff8126d7c0>] idr_pre_get+0x60/0x90
> >  [<ffffffff8126dd8b>] ida_pre_get+0x1b/0x90
> >  [<ffffffff810593b2>] create_worker+0x42/0x170
> >  [<ffffffff81ae441d>] init_workqueues+0x1f2/0x393
> >  [<ffffffff81ae422b>] ? usermodehelper_init+0x36/0x36
> >  [<ffffffff81ae422b>] ? usermodehelper_init+0x36/0x36
> >  [<ffffffff81002122>] do_one_initcall+0x122/0x180
> >  [<ffffffff81acbc7a>] kernel_init+0x9b/0x1f6
> >  [<ffffffff815c1f74>] kernel_thread_helper+0x4/0x10
> >  [<ffffffff815c0274>] ? retint_restore_args+0x13/0x13
> >  [<ffffffff81acbbdf>] ? start_kernel+0x3d2/0x3d2
> >  [<ffffffff815c1f70>] ? gs_change+0x13/0x13 

Using SLUB are you?

Looks like SLUB is buggy here.. does this fix it?

---
 mm/slub.c |   14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/mm/slub.c b/mm/slub.c
index fb2ef09..6b9e3f6 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1314,13 +1314,7 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
 			stat(s, ORDER_FALLBACK);
 	}
 
-	if (flags & __GFP_WAIT)
-		local_irq_disable();
-
-	if (!page)
-		return NULL;
-
-	if (kmemcheck_enabled
+	if (page && kmemcheck_enabled
 		&& !(s->flags & (SLAB_NOTRACK | DEBUG_DEFAULT_FLAGS))) {
 		int pages = 1 << oo_order(oo);
 
@@ -1336,6 +1330,12 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
 			kmemcheck_mark_unallocated_pages(page, pages);
 	}
 
+	if (flags & __GFP_WAIT)
+		local_irq_disable();
+
+	if (!page)
+		return NULL;
+
 	page->objects = oo_objects(oo);
 	mod_zone_page_state(page_zone(page),
 		(s->flags & SLAB_RECLAIM_ACCOUNT) ?