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.
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 <atom...@redhat.com> Reviewed-by: Rik van Riel <r...@redhat.com> 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 from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
