As the comments of page_mapcount_is_type() indicate, the parameter passed to the function should be one more than page->__mapcount. However, page->__mapcount is passed to the function by commit 4ffca5a96678 ("mm: support only one page_type per page") where page_type_has_type() is replaced by page_mapcount_is_type(), but the parameter isn't adjusted. Fix the parameter passed to page_mapcount_is_type() to be (page->__mapcount + 1). Fixes: 4ffca5a96678 ("mm: support only one page_type per page") Cc: stable@xxxxxxxxxxxxxxx # v6.12+ Signed-off-by: Gavin Shan <gshan@xxxxxxxxxx> --- mm/debug.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/debug.c b/mm/debug.c index 8d2acf432385..b6bd9555ec7b 100644 --- a/mm/debug.c +++ b/mm/debug.c @@ -71,10 +71,10 @@ static void __dump_folio(struct folio *folio, struct page *page, unsigned long pfn, unsigned long idx) { struct address_space *mapping = folio_mapping(folio); - int mapcount = atomic_read(&page->_mapcount); + int mapcount = atomic_read(&page->_mapcount) + 1; char *type = ""; - mapcount = page_mapcount_is_type(mapcount) ? 0 : mapcount + 1; + mapcount = page_mapcount_is_type(mapcount) ? 0 : mapcount; pr_warn("page: refcount:%d mapcount:%d mapping:%p index:%#lx pfn:%#lx\n", folio_ref_count(folio), mapcount, mapping, folio->index + idx, pfn); -- 2.48.1