| From: Miaohe Lin <linmiaohe@huawei.com> |
| Subject: mm/migration: fix potential invalid node access for reclaim-based migration |
| |
| If we failed to setup hotplug state callbacks for mm/demotion:online in |
| some corner cases, node_demotion will be left uninitialized. Invalid node |
| might be returned from the next_demotion_node() when doing reclaim-based |
| migration. Use kcalloc to allocate node_demotion to fix the issue. |
| |
| Link: https://lkml.kernel.org/r/20220318111709.60311-11-linmiaohe@huawei.com |
| Fixes: ac16ec835314 ("mm: migrate: support multiple target nodes demotion") |
| Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> |
| Reviewed-by: "Huang, Ying" <ying.huang@intel.com> |
| Cc: Alistair Popple <apopple@nvidia.com> |
| Cc: Baolin Wang <baolin.wang@linux.alibaba.com> |
| Cc: Muchun Song <songmuchun@bytedance.com> |
| Cc: Zi Yan <ziy@nvidia.com> |
| Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
| --- |
| |
| mm/migrate.c | 6 +++--- |
| 1 file changed, 3 insertions(+), 3 deletions(-) |
| |
| --- a/mm/migrate.c~mm-migration-fix-potential-invalid-node-access-for-reclaim-based-migration |
| +++ a/mm/migrate.c |
| @@ -2479,9 +2479,9 @@ static int __meminit migrate_on_reclaim_ |
| |
| void __init migrate_on_reclaim_init(void) |
| { |
| - node_demotion = kmalloc_array(nr_node_ids, |
| - sizeof(struct demotion_nodes), |
| - GFP_KERNEL); |
| + node_demotion = kcalloc(nr_node_ids, |
| + sizeof(struct demotion_nodes), |
| + GFP_KERNEL); |
| WARN_ON(!node_demotion); |
| |
| hotplug_memory_notifier(migrate_on_reclaim_callback, 100); |
| _ |
