Let's sanity-check in folio_set_order() whether we would be trying to create a folio with an order that would make it exceed MAX_FOLIO_ORDER.
This will enable the check whenever a folio/compound page is initialized through prepare_compound_head() / prepare_compound_page() with CONFIG_DEBUG_VM set.
Reviewed-by: Zi Yan ziy@nvidia.com Reviewed-by: Wei Yang richard.weiyang@gmail.com Reviewed-by: Lorenzo Stoakes lorenzo.stoakes@oracle.com Reviewed-by: Liam R. Howlett Liam.Howlett@oracle.com Signed-off-by: David Hildenbrand david@redhat.com --- mm/internal.h | 1 + 1 file changed, 1 insertion(+)
diff --git a/mm/internal.h b/mm/internal.h index 45da9ff5694f6..9b0129531d004 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -755,6 +755,7 @@ static inline void folio_set_order(struct folio *folio, unsigned int order) { if (WARN_ON_ONCE(!order || !folio_test_large(folio))) return; + VM_WARN_ON_ONCE(order > MAX_FOLIO_ORDER);
folio->_flags_1 = (folio->_flags_1 & ~0xffUL) | order; #ifdef NR_PAGES_IN_LARGE_FOLIO