mm: slab: Verify the nodeid passed to ____cache_alloc_node
authorAaron Tomlin <atomlin@redhat.com>
Fri, 26 Apr 2013 15:15:34 +0000 (16:15 +0100)
committerPekka Enberg <penberg@kernel.org>
Wed, 1 May 2013 07:57:43 +0000 (10:57 +0300)
commit14e50c6a9bc2b283bb4021026226268312ceefdd
tree37543ffb4bbeaf9cc4fb191c531f4956f7d8357c
parent7cccd80b4397699902aced1ad3d692d384aaab77
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.

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.

[1]: https://bugzilla.kernel.org/show_bug.cgi?id=42967

Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Christoph Lameter <cl@linux.com>
Acked-by: Rafael Aquini <aquini@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
mm/slab.c