From: Wang Wensheng <wangwensheng4@huawei.com> ascend inclusion category: bugfix bugzilla: NA CVE: NA ------------------- Check whether the topological structure of the DDR/HBM brokes our assumption or not. If it got broken we just return the input nid, or an invalid nid could be returned and it may break the kernel. Fixes: aabbfd385ab2 ("numa: Move the management structures for cdm nodes to ddr") Signed-off-by: Wang Wensheng <wangwensheng4@huawei.com> Reviewed-by: Weilong Chen <chenweilong@huawei.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- arch/arm64/mm/numa.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/arm64/mm/numa.c b/arch/arm64/mm/numa.c index a194bad6fdfcf..82d53927554d8 100644 --- a/arch/arm64/mm/numa.c +++ b/arch/arm64/mm/numa.c @@ -85,7 +85,11 @@ int __init cdm_node_to_ddr_node(int nid) nodes_xor(ddr_mask, cdmmask, numa_nodes_parsed); nr_ddr = nodes_weight(ddr_mask); - cdm_per_part = nr_cdm / nr_ddr ? : 1; + cdm_per_part = nr_cdm / nr_ddr; + + if (cdm_per_part == 0 || nid < nr_ddr) + /* our assumption has borken, just return the original nid. */ + return nid; fake_nid = (nid - nr_ddr) / cdm_per_part; fake_nid = !node_isset(fake_nid, cdmmask) ? fake_nid : nid; -- 2.25.1