There are only `RESERVE_VMEMMAP_SIZE / sizeof(struct page)` struct pages
can be used when CONFIG_HUGETLB_PAGE_FREE_VMEMMAP, so add a BUILD_BUG_ON
to catch this invalid usage of tail struct page.
Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
---
mm/hugetlb.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index e66c3f10c583..63995ba74b6b 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -3994,6 +3994,8 @@ static int __init hugetlb_init(void)
#ifdef CONFIG_HUGETLB_PAGE_FREE_VMEMMAP
BUILD_BUG_ON_NOT_POWER_OF_2(sizeof(struct page));
+ BUILD_BUG_ON(NR_USED_SUBPAGE >=
+ RESERVE_VMEMMAP_SIZE / sizeof(struct page));
#endif
if (!hugepages_supported()) {
--
2.20.1
