Merge tag 'mm-hotfixes-stable-2024-04-26-13-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull misc fixes from Andrew Morton:
 "11 hotfixes. 8 are cc:stable and the remaining 3 (nice ratio!) address
  post-6.8 issues or aren't considered suitable for backporting.

  All except one of these are for MM. I see no particular theme - it's
  singletons all over"

* tag 'mm-hotfixes-stable-2024-04-26-13-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  mm/hugetlb: fix DEBUG_LOCKS_WARN_ON(1) when dissolve_free_hugetlb_folio()
  selftests: mm: protection_keys: save/restore nr_hugepages value from launch script
  stackdepot: respect __GFP_NOLOCKDEP allocation flag
  hugetlb: check for anon_vma prior to folio allocation
  mm: zswap: fix shrinker NULL crash with cgroup_disable=memory
  mm: turn folio_test_hugetlb into a PageType
  mm: support page_mapcount() on page_has_type() pages
  mm: create FOLIO_FLAG_FALSE and FOLIO_TYPE_OPS macros
  mm/hugetlb: fix missing hugetlb_lock for resv uncharge
  selftests: mm: fix unused and uninitialized variable warning
  selftests/harness: remove use of LINE_MAX

1 files changed, 2 insertions, 5 deletions

diff --git a/fs/proc/page.c b/fs/proc/page.c
index 195b077c0fac..9223856c934b 100644
--- a/fs/proc/page.c
+++ b/fs/proc/page.c
@@ -67,7 +67,7 @@ static ssize_t kpagecount_read(struct file *file, char __user *buf,
 		 */
 		ppage = pfn_to_online_page(pfn);
 
-		if (!ppage || PageSlab(ppage) || page_has_type(ppage))
+		if (!ppage)
 			pcount = 0;
 		else
 			pcount = page_mapcount(ppage);
@@ -124,11 +124,8 @@ u64 stable_page_flags(struct page *page)
 
 	/*
 	 * pseudo flags for the well known (anonymous) memory mapped pages
-	 *
-	 * Note that page->_mapcount is overloaded in SLAB, so the
-	 * simple test in page_mapped() is not enough.
 	 */
-	if (!PageSlab(page) && page_mapped(page))
+	if (page_mapped(page))
 		u |= 1 << KPF_MMAP;
 	if (PageAnon(page))
 		u |= 1 << KPF_ANON;