When hugetlbfs is started with a non-default page size, it is possible that no hstate is initialized for the page sized used by transparent huge pages. This causes copy_huge_page to crash on a null pointer. Make sure we always have an hpage initialized for the page sized used by THP. Signed-off-by: Rik van Riel <riel@xxxxxxxxxx> Reported-by: Chao Yang <chayang@xxxxxxxxxx> --- mm/huge_memory.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 5749bcf..583e9d3 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -624,6 +624,13 @@ static int __init hugepage_init(void) return -EINVAL; } + /* + * Make sure an hstate is initialized for our page size, + * even if hugetlbfs is using a non-default page size. + */ + if (!size_to_hstate(PMD_PAGE_SIZE)) + hugetlb_add_hstate(HUGETLB_PAGE_ORDER); + err = hugepage_init_sysfs(&hugepage_kobj); if (err) return err; -- All Rights Reversed -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
