Re: [bug] SLUB & freeing locks [was: Re: 2.6.23-rc1: knownregressions with patches]

[Peter Zijlstra]

On Thu, 2007-07-26 at 11:26 +0200, Peter Zijlstra wrote:
> On Thu, 2007-07-26 at 11:10 +0200, Ingo Molnar wrote:
> > there's a new regression:
> > 
> > SLUB does not seem to call debug_check_no_locks_freed() - hence on SLUB 
> > we will not notice certain types of freeing races. (such as freeing an 
> > object still locked and used on another CPU.) SLAB does this corretly.

Oh, nm, it doesn't call debug_check_no_locks_freed() at all.

This should do I guess.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
---
 mm/slub.c |    1 +
 1 file changed, 1 insertion(+)

Index: linux-2.6/mm/slub.c
===================================================================
--- linux-2.6.orig/mm/slub.c
+++ linux-2.6/mm/slub.c
@@ -1656,6 +1656,7 @@ static void __always_inline slab_free(st
 	unsigned long flags;
 
 	local_irq_save(flags);
+	debug_check_no_locks_freed(object, s->size);
 	if (likely(page == s->cpu_slab[smp_processor_id()] &&
 						!SlabDebug(page))) {
 		object[page->offset] = page->lockless_freelist;


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