14 hotfixes. 10 are cc:stable and the remainder address post-6.7 issues

or aren't considered appropriate for backporting.
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Merge tag 'mm-hotfixes-stable-2024-02-22-15-02' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull misc fixes from Andrew Morton:
 "A batch of MM (and one non-MM) hotfixes.

  Ten are cc:stable and the remainder address post-6.7 issues or aren't
  considered appropriate for backporting"

* tag 'mm-hotfixes-stable-2024-02-22-15-02' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  kasan: guard release_free_meta() shadow access with kasan_arch_is_ready()
  mm/damon/lru_sort: fix quota status loss due to online tunings
  mm/damon/reclaim: fix quota stauts loss due to online tunings
  MAINTAINERS: mailmap: update Shakeel's email address
  mm/damon/sysfs-schemes: handle schemes sysfs dir removal before commit_schemes_quota_goals
  mm: memcontrol: clarify swapaccount=0 deprecation warning
  mm/memblock: add MEMBLOCK_RSRV_NOINIT into flagname[] array
  mm/zswap: invalidate duplicate entry when !zswap_enabled
  lib/Kconfig.debug: TEST_IOV_ITER depends on MMU
  mm/swap: fix race when skipping swapcache
  mm/swap_state: update zswap LRU's protection range with the folio locked
  selftests/mm: uffd-unit-test check if huge page size is 0
  mm/damon/core: check apply interval in damon_do_apply_schemes()
  mm: zswap: fix missing folio cleanup in writeback race path

.mailmap

@@ -553,6 +553,7 @@ Senthilkumar N L <quic_snlakshm@quicinc.com> <snlakshm@codeaurora.org>
 Serge Hallyn <sergeh@kernel.org> <serge.hallyn@canonical.com>
 Serge Hallyn <sergeh@kernel.org> <serue@us.ibm.com>
 Seth Forshee <sforshee@kernel.org> <seth.forshee@canonical.com>
+Shakeel Butt <shakeel.butt@linux.dev> <shakeelb@google.com>
 Shannon Nelson <shannon.nelson@amd.com> <snelson@pensando.io>
 Shannon Nelson <shannon.nelson@amd.com> <shannon.nelson@intel.com>
 Shannon Nelson <shannon.nelson@amd.com> <shannon.nelson@oracle.com>

MAINTAINERS

@@ -5378,7 +5378,7 @@ CONTROL GROUP - MEMORY RESOURCE CONTROLLER (MEMCG)
 M:	Johannes Weiner <hannes@cmpxchg.org>
 M:	Michal Hocko <mhocko@kernel.org>
 M:	Roman Gushchin <roman.gushchin@linux.dev>
-M:	Shakeel Butt <shakeelb@google.com>
+M:	Shakeel Butt <shakeel.butt@linux.dev>
 R:	Muchun Song <muchun.song@linux.dev>
 L:	cgroups@vger.kernel.org
 L:	linux-mm@kvack.org

include/linux/swap.h

@@ -549,6 +549,11 @@ static inline int swap_duplicate(swp_entry_t swp)
 	return 0;
 }
 
+static inline int swapcache_prepare(swp_entry_t swp)
+{
+	return 0;
+}
+
 static inline void swap_free(swp_entry_t swp)
 {
 }

lib/Kconfig.debug

@@ -2235,6 +2235,7 @@ config TEST_DIV64
 config TEST_IOV_ITER
 	tristate "Test iov_iter operation" if !KUNIT_ALL_TESTS
 	depends on KUNIT
+	depends on MMU
 	default KUNIT_ALL_TESTS
 	help
 	  Enable this to turn on testing of the operation of the I/O iterator

mm/damon/core.c

@@ -1026,6 +1026,9 @@ static void damon_do_apply_schemes(struct damon_ctx *c,
 	damon_for_each_scheme(s, c) {
 		struct damos_quota *quota = &s->quota;
 
+		if (c->passed_sample_intervals != s->next_apply_sis)
+			continue;
+
 		if (!s->wmarks.activated)
 			continue;
 
@@ -1176,10 +1179,6 @@ static void kdamond_apply_schemes(struct damon_ctx *c)
 		if (c->passed_sample_intervals != s->next_apply_sis)
 			continue;
 
-		s->next_apply_sis +=
-			(s->apply_interval_us ? s->apply_interval_us :
-			 c->attrs.aggr_interval) / sample_interval;
-
 		if (!s->wmarks.activated)
 			continue;
 
@@ -1195,6 +1194,14 @@ static void kdamond_apply_schemes(struct damon_ctx *c)
 		damon_for_each_region_safe(r, next_r, t)
 			damon_do_apply_schemes(c, t, r);
 	}
+
+	damon_for_each_scheme(s, c) {
+		if (c->passed_sample_intervals != s->next_apply_sis)
+			continue;
+		s->next_apply_sis +=
+			(s->apply_interval_us ? s->apply_interval_us :
+			 c->attrs.aggr_interval) / sample_interval;
+	}
 }
 
 /*

mm/damon/lru_sort.c

@@ -185,9 +185,21 @@ static struct damos *damon_lru_sort_new_cold_scheme(unsigned int cold_thres)
 	return damon_lru_sort_new_scheme(&pattern, DAMOS_LRU_DEPRIO);
 }
 
+static void damon_lru_sort_copy_quota_status(struct damos_quota *dst,
+		struct damos_quota *src)
+{
+	dst->total_charged_sz = src->total_charged_sz;
+	dst->total_charged_ns = src->total_charged_ns;
+	dst->charged_sz = src->charged_sz;
+	dst->charged_from = src->charged_from;
+	dst->charge_target_from = src->charge_target_from;
+	dst->charge_addr_from = src->charge_addr_from;
+}
+
 static int damon_lru_sort_apply_parameters(void)
 {
-	struct damos *scheme;
+	struct damos *scheme, *hot_scheme, *cold_scheme;
+	struct damos *old_hot_scheme = NULL, *old_cold_scheme = NULL;
 	unsigned int hot_thres, cold_thres;
 	int err = 0;
 
@@ -195,18 +207,35 @@ static int damon_lru_sort_apply_parameters(void)
 	if (err)
 		return err;
 
+	damon_for_each_scheme(scheme, ctx) {
+		if (!old_hot_scheme) {
+			old_hot_scheme = scheme;
+			continue;
+		}
+		old_cold_scheme = scheme;
+	}
+
 	hot_thres = damon_max_nr_accesses(&damon_lru_sort_mon_attrs) *
 		hot_thres_access_freq / 1000;
-	scheme = damon_lru_sort_new_hot_scheme(hot_thres);
-	if (!scheme)
+	hot_scheme = damon_lru_sort_new_hot_scheme(hot_thres);
+	if (!hot_scheme)
 		return -ENOMEM;
-	damon_set_schemes(ctx, &scheme, 1);
+	if (old_hot_scheme)
+		damon_lru_sort_copy_quota_status(&hot_scheme->quota,
+				&old_hot_scheme->quota);
 
 	cold_thres = cold_min_age / damon_lru_sort_mon_attrs.aggr_interval;
-	scheme = damon_lru_sort_new_cold_scheme(cold_thres);
-	if (!scheme)
+	cold_scheme = damon_lru_sort_new_cold_scheme(cold_thres);
+	if (!cold_scheme) {
+		damon_destroy_scheme(hot_scheme);
 		return -ENOMEM;
-	damon_add_scheme(ctx, scheme);
+	}
+	if (old_cold_scheme)
+		damon_lru_sort_copy_quota_status(&cold_scheme->quota,
+				&old_cold_scheme->quota);
+
+	damon_set_schemes(ctx, &hot_scheme, 1);
+	damon_add_scheme(ctx, cold_scheme);
 
 	return damon_set_region_biggest_system_ram_default(target,
 					&monitor_region_start,

mm/damon/reclaim.c

@@ -150,9 +150,20 @@ static struct damos *damon_reclaim_new_scheme(void)
 			&damon_reclaim_wmarks);
 }
 
+static void damon_reclaim_copy_quota_status(struct damos_quota *dst,
+		struct damos_quota *src)
+{
+	dst->total_charged_sz = src->total_charged_sz;
+	dst->total_charged_ns = src->total_charged_ns;
+	dst->charged_sz = src->charged_sz;
+	dst->charged_from = src->charged_from;
+	dst->charge_target_from = src->charge_target_from;
+	dst->charge_addr_from = src->charge_addr_from;
+}
+
 static int damon_reclaim_apply_parameters(void)
 {
-	struct damos *scheme;
+	struct damos *scheme, *old_scheme;
 	struct damos_filter *filter;
 	int err = 0;
 
@@ -164,6 +175,11 @@ static int damon_reclaim_apply_parameters(void)
 	scheme = damon_reclaim_new_scheme();
 	if (!scheme)
 		return -ENOMEM;
+	if (!list_empty(&ctx->schemes)) {
+		damon_for_each_scheme(old_scheme, ctx)
+			damon_reclaim_copy_quota_status(&scheme->quota,
+					&old_scheme->quota);
+	}
 	if (skip_anon) {
 		filter = damos_new_filter(DAMOS_FILTER_TYPE_ANON, true);
 		if (!filter) {

mm/damon/sysfs-schemes.c

@@ -1905,6 +1905,10 @@ void damos_sysfs_set_quota_scores(struct damon_sysfs_schemes *sysfs_schemes,
 	damon_for_each_scheme(scheme, ctx) {
 		struct damon_sysfs_scheme *sysfs_scheme;
 
+		/* user could have removed the scheme sysfs dir */
+		if (i >= sysfs_schemes->nr)
+			break;
+
 		sysfs_scheme = sysfs_schemes->schemes_arr[i];
 		damos_sysfs_set_quota_score(sysfs_scheme->quotas->goals,
 				&scheme->quota);

mm/kasan/generic.c

@@ -522,6 +522,9 @@ static void release_alloc_meta(struct kasan_alloc_meta *meta)
 
 static void release_free_meta(const void *object, struct kasan_free_meta *meta)
 {
+	if (!kasan_arch_is_ready())
+		return;
+
 	/* Check if free meta is valid. */
 	if (*(u8 *)kasan_mem_to_shadow(object) != KASAN_SLAB_FREE_META)
 		return;

mm/memblock.c

@@ -2249,6 +2249,7 @@ static const char * const flagname[] = {
 	[ilog2(MEMBLOCK_MIRROR)] = "MIRROR",
 	[ilog2(MEMBLOCK_NOMAP)] = "NOMAP",
 	[ilog2(MEMBLOCK_DRIVER_MANAGED)] = "DRV_MNG",
+	[ilog2(MEMBLOCK_RSRV_NOINIT)] = "RSV_NIT",
 };
 
 static int memblock_debug_show(struct seq_file *m, void *private)

mm/memcontrol.c

@@ -7971,9 +7971,13 @@ bool mem_cgroup_swap_full(struct folio *folio)
 
 static int __init setup_swap_account(char *s)
 {
-	pr_warn_once("The swapaccount= commandline option is deprecated. "
-		     "Please report your usecase to linux-mm@kvack.org if you "
-		     "depend on this functionality.\n");
+	bool res;
+
+	if (!kstrtobool(s, &res) && !res)
+		pr_warn_once("The swapaccount=0 commandline option is deprecated "
+			     "in favor of configuring swap control via cgroupfs. "
+			     "Please report your usecase to linux-mm@kvack.org if you "
+			     "depend on this functionality.\n");
 	return 1;
 }
 __setup("swapaccount=", setup_swap_account);

mm/memory.c

@@ -3799,6 +3799,7 @@ vm_fault_t do_swap_page(struct vm_fault *vmf)
 	struct page *page;
 	struct swap_info_struct *si = NULL;
 	rmap_t rmap_flags = RMAP_NONE;
+	bool need_clear_cache = false;
 	bool exclusive = false;
 	swp_entry_t entry;
 	pte_t pte;
@@ -3867,6 +3868,20 @@ vm_fault_t do_swap_page(struct vm_fault *vmf)
 	if (!folio) {
 		if (data_race(si->flags & SWP_SYNCHRONOUS_IO) &&
 		    __swap_count(entry) == 1) {
+			/*
+			 * Prevent parallel swapin from proceeding with
+			 * the cache flag. Otherwise, another thread may
+			 * finish swapin first, free the entry, and swapout
+			 * reusing the same entry. It's undetectable as
+			 * pte_same() returns true due to entry reuse.
+			 */
+			if (swapcache_prepare(entry)) {
+				/* Relax a bit to prevent rapid repeated page faults */
+				schedule_timeout_uninterruptible(1);
+				goto out;
+			}
+			need_clear_cache = true;
+
 			/* skip swapcache */
 			folio = vma_alloc_folio(GFP_HIGHUSER_MOVABLE, 0,
 						vma, vmf->address, false);
@@ -4117,6 +4132,9 @@ vm_fault_t do_swap_page(struct vm_fault *vmf)
 	if (vmf->pte)
 		pte_unmap_unlock(vmf->pte, vmf->ptl);
 out:
+	/* Clear the swap cache pin for direct swapin after PTL unlock */
+	if (need_clear_cache)
+		swapcache_clear(si, entry);
 	if (si)
 		put_swap_device(si);
 	return ret;
@@ -4131,6 +4149,8 @@ vm_fault_t do_swap_page(struct vm_fault *vmf)
 		folio_unlock(swapcache);
 		folio_put(swapcache);
 	}
+	if (need_clear_cache)
+		swapcache_clear(si, entry);
 	if (si)
 		put_swap_device(si);
 	return ret;

mm/swap.h

@@ -41,6 +41,7 @@ void __delete_from_swap_cache(struct folio *folio,
 void delete_from_swap_cache(struct folio *folio);
 void clear_shadow_from_swap_cache(int type, unsigned long begin,
 				  unsigned long end);
+void swapcache_clear(struct swap_info_struct *si, swp_entry_t entry);
 struct folio *swap_cache_get_folio(swp_entry_t entry,
 		struct vm_area_struct *vma, unsigned long addr);
 struct folio *filemap_get_incore_folio(struct address_space *mapping,
@@ -97,6 +98,10 @@ static inline int swap_writepage(struct page *p, struct writeback_control *wbc)
 	return 0;
 }
 
+static inline void swapcache_clear(struct swap_info_struct *si, swp_entry_t entry)
+{
+}
+
 static inline struct folio *swap_cache_get_folio(swp_entry_t entry,
 		struct vm_area_struct *vma, unsigned long addr)
 {

mm/swap_state.c

@@ -680,9 +680,10 @@ struct folio *swap_cluster_readahead(swp_entry_t entry, gfp_t gfp_mask,
 	/* The page was likely read above, so no need for plugging here */
 	folio = __read_swap_cache_async(entry, gfp_mask, mpol, ilx,
 					&page_allocated, false);
-	if (unlikely(page_allocated))
+	if (unlikely(page_allocated)) {
+		zswap_folio_swapin(folio);
 		swap_read_folio(folio, false, NULL);
-	zswap_folio_swapin(folio);
+	}
 	return folio;
 }
 
@@ -855,9 +856,10 @@ static struct folio *swap_vma_readahead(swp_entry_t targ_entry, gfp_t gfp_mask,
 	/* The folio was likely read above, so no need for plugging here */
 	folio = __read_swap_cache_async(targ_entry, gfp_mask, mpol, targ_ilx,
 					&page_allocated, false);
-	if (unlikely(page_allocated))
+	if (unlikely(page_allocated)) {
+		zswap_folio_swapin(folio);
 		swap_read_folio(folio, false, NULL);
-	zswap_folio_swapin(folio);
+	}
 	return folio;
 }
 

mm/swapfile.c

@@ -3365,6 +3365,19 @@ int swapcache_prepare(swp_entry_t entry)
 	return __swap_duplicate(entry, SWAP_HAS_CACHE);
 }
 
+void swapcache_clear(struct swap_info_struct *si, swp_entry_t entry)
+{
+	struct swap_cluster_info *ci;
+	unsigned long offset = swp_offset(entry);
+	unsigned char usage;
+
+	ci = lock_cluster_or_swap_info(si, offset);
+	usage = __swap_entry_free_locked(si, offset, SWAP_HAS_CACHE);
+	unlock_cluster_or_swap_info(si, ci);
+	if (!usage)
+		free_swap_slot(entry);
+}
+
 struct swap_info_struct *swp_swap_info(swp_entry_t entry)
 {
 	return swap_type_to_swap_info(swp_type(entry));

mm/zswap.c

@@ -377,10 +377,9 @@ void zswap_folio_swapin(struct folio *folio)
 {
 	struct lruvec *lruvec;
 
-	if (folio) {
-		lruvec = folio_lruvec(folio);
-		atomic_long_inc(&lruvec->zswap_lruvec_state.nr_zswap_protected);
-	}
+	VM_WARN_ON_ONCE(!folio_test_locked(folio));
+	lruvec = folio_lruvec(folio);
+	atomic_long_inc(&lruvec->zswap_lruvec_state.nr_zswap_protected);
 }
 
 /*********************************
@@ -1440,6 +1439,8 @@ static int zswap_writeback_entry(struct zswap_entry *entry,
 	if (zswap_rb_search(&tree->rbroot, swp_offset(entry->swpentry)) != entry) {
 		spin_unlock(&tree->lock);
 		delete_from_swap_cache(folio);
+		folio_unlock(folio);
+		folio_put(folio);
 		return -ENOMEM;
 	}
 	spin_unlock(&tree->lock);
@@ -1517,7 +1518,7 @@ bool zswap_store(struct folio *folio)
 	if (folio_test_large(folio))
 		return false;
 
-	if (!zswap_enabled || !tree)
+	if (!tree)
 		return false;
 
 	/*
@@ -1532,6 +1533,10 @@ bool zswap_store(struct folio *folio)
 		zswap_invalidate_entry(tree, dupentry);
 	}
 	spin_unlock(&tree->lock);
+
+	if (!zswap_enabled)
+		return false;
+
 	objcg = get_obj_cgroup_from_folio(folio);
 	if (objcg && !obj_cgroup_may_zswap(objcg)) {
 		memcg = get_mem_cgroup_from_objcg(objcg);

tools/testing/selftests/mm/uffd-unit-tests.c

@@ -1517,6 +1517,12 @@ int main(int argc, char *argv[])
 				continue;
 
 			uffd_test_start("%s on %s", test->name, mem_type->name);
+			if ((mem_type->mem_flag == MEM_HUGETLB ||
+			    mem_type->mem_flag == MEM_HUGETLB_PRIVATE) &&
+			    (default_huge_page_size() == 0)) {
+				uffd_test_skip("huge page size is 0, feature missing?");
+				continue;
+			}
 			if (!uffd_feature_supported(test)) {
 				uffd_test_skip("feature missing");
 				continue;