On Sat, Jul 22, 2023 at 11:15:06PM +0000, Pasha Tatashin wrote: > static struct page_table_check *get_page_table_check(struct page_ext *page_ext) > { > - BUG_ON(!page_ext); > + PAGE_TABLE_CHECK_WARN(!page_ext); > + > return (void *)(page_ext) + page_table_check_ops.offset; > } [...] > @@ -137,15 +144,15 @@ void __page_table_check_zero(struct page *page, unsigned int order) > struct page_ext *page_ext; > unsigned long i; > > - BUG_ON(PageSlab(page)); > + PAGE_TABLE_CHECK_WARN(PageSlab(page)); > > page_ext = page_ext_get(page); > - BUG_ON(!page_ext); > + PAGE_TABLE_CHECK_WARN(!page_ext); > for (i = 0; i < (1ul << order); i++) { > struct page_table_check *ptc = get_page_table_check(page_ext); Seems like we're going to warn about !page_ext twice? Or more than twice -- once per tail page? But then we'll crash because page_ext was NULL and offset was small?