On Tue, Apr 23, 2013 at 10:31:36AM -0400, Aaron Tomlin wrote: > Hi, > > This patch is in response to BZ#42967 [1]. > Using VM_BUG_ON so it's used only when CONFIG_DEBUG_VM is set, > given that ____cache_alloc_node() is a hot code path. > This seems to be a valid condition to BUG_ON, though. > Cheers, > Aaron > > [1]: https://bugzilla.kernel.org/show_bug.cgi?id=42967 > > ---8<--- > mm: slab: Verify the nodeid passed to ____cache_alloc_node > > If the nodeid is > num_online_nodes() this can cause an > Oops and a panic(). The purpose of this patch is to assert > if this condition is true to aid debugging efforts rather > than some random NULL pointer dereference or page fault. > > Signed-off-by: Aaron Tomlin <atomlin@xxxxxxxxxx> > Reviewed-by: Rik van Riel <riel@xxxxxxxxxx> > Acked-by: Rafael Aquini <aquini@xxxxxxxxxx> > > slab.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/mm/slab.c b/mm/slab.c > index e7667a3..735e8bd 100644 > --- a/mm/slab.c > +++ b/mm/slab.c > -3412,6 +3412,7 @@ static void *____cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, > void *obj; > int x; > > + VM_BUG_ON(nodeid > num_online_nodes()); > l3 = cachep->nodelists[nodeid]; > BUG_ON(!l3); -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>