Merge tag 'mm-hotfixes-stable-2023-03-24-17-09' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull misc fixes from Andrew Morton:
 "21 hotfixes, 8 of which are cc:stable. 11 are for MM, the remainder
  are for other subsystems"

* tag 'mm-hotfixes-stable-2023-03-24-17-09' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (21 commits)
  mm: mmap: remove newline at the end of the trace
  mailmap: add entries for Richard Leitner
  kcsan: avoid passing -g for test
  kfence: avoid passing -g for test
  mm: kfence: fix using kfence_metadata without initialization in show_object()
  lib: dhry: fix unstable smp_processor_id(_) usage
  mailmap: add entry for Enric Balletbo i Serra
  mailmap: map Sai Prakash Ranjan's old address to his current one
  mailmap: map Rajendra Nayak's old address to his current one
  Revert "kasan: drop skip_kasan_poison variable in free_pages_prepare"
  mailmap: add entry for Tobias Klauser
  kasan, powerpc: don't rename memintrinsics if compiler adds prefixes
  mm/ksm: fix race with VMA iteration and mm_struct teardown
  kselftest: vm: fix unused variable warning
  mm: fix error handling for map_deny_write_exec
  mm: deduplicate error handling for map_deny_write_exec
  checksyscalls: ignore fstat to silence build warning on LoongArch
  nilfs2: fix kernel-infoleak in nilfs_ioctl_wrap_copy()
  test_maple_tree: add more testing for mas_empty_area()
  maple_tree: fix mas_skip_node() end slot detection
  ...

7 files changed, 45 insertions, 18 deletions

diff --git a/mm/kfence/Makefile b/mm/kfence/Makefile
index 0bb95728a784..2de2a58d11a1 100644
--- a/mm/kfence/Makefile
+++ b/mm/kfence/Makefile
@@ -2,5 +2,5 @@
 
 obj-y := core.o report.o
 
-CFLAGS_kfence_test.o := -g -fno-omit-frame-pointer -fno-optimize-sibling-calls
+CFLAGS_kfence_test.o := -fno-omit-frame-pointer -fno-optimize-sibling-calls
 obj-$(CONFIG_KFENCE_KUNIT_TEST) += kfence_test.o
diff --git a/mm/kfence/core.c b/mm/kfence/core.c
index 5349c37a5dac..79c94ee55f97 100644
--- a/mm/kfence/core.c
+++ b/mm/kfence/core.c
@@ -726,10 +726,14 @@ static const struct seq_operations objects_sops = {
 };
 DEFINE_SEQ_ATTRIBUTE(objects);
 
-static int __init kfence_debugfs_init(void)
+static int kfence_debugfs_init(void)
 {
-	struct dentry *kfence_dir = debugfs_create_dir("kfence", NULL);
+	struct dentry *kfence_dir;
 
+	if (!READ_ONCE(kfence_enabled))
+		return 0;
+
+	kfence_dir = debugfs_create_dir("kfence", NULL);
 	debugfs_create_file("stats", 0444, kfence_dir, NULL, &stats_fops);
 	debugfs_create_file("objects", 0400, kfence_dir, NULL, &objects_fops);
 	return 0;
@@ -883,6 +887,8 @@ static int kfence_init_late(void)
 	}
 
 	kfence_init_enable();
+	kfence_debugfs_init();
+
 	return 0;
 }
 
diff --git a/mm/ksm.c b/mm/ksm.c
index ad591b779d53..2b8d30068cbb 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -988,9 +988,15 @@ static int unmerge_and_remove_all_rmap_items(void)
 
 		mm = mm_slot->slot.mm;
 		mmap_read_lock(mm);
+
+		/*
+		 * Exit right away if mm is exiting to avoid lockdep issue in
+		 * the maple tree
+		 */
+		if (ksm_test_exit(mm))
+			goto mm_exiting;
+
 		for_each_vma(vmi, vma) {
-			if (ksm_test_exit(mm))
-				break;
 			if (!(vma->vm_flags & VM_MERGEABLE) || !vma->anon_vma)
 				continue;
 			err = unmerge_ksm_pages(vma,
@@ -999,6 +1005,7 @@ static int unmerge_and_remove_all_rmap_items(void)
 				goto error;
 		}
 
+mm_exiting:
 		remove_trailing_rmap_items(&mm_slot->rmap_list);
 		mmap_read_unlock(mm);
 
diff --git a/mm/mmap.c b/mm/mmap.c
index 740b54be3ed4..ad499f7b767f 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2621,12 +2621,7 @@ cannot_expand:
 
 	if (map_deny_write_exec(vma, vma->vm_flags)) {
 		error = -EACCES;
-		if (file)
-			goto close_and_free_vma;
-		else if (vma->vm_file)
-			goto unmap_and_free_vma;
-		else
-			goto free_vma;
+		goto close_and_free_vma;
 	}
 
 	/* Allow architectures to sanity-check the vm_flags */
diff --git a/mm/mprotect.c b/mm/mprotect.c
index 231929f119d9..13e84d8c0797 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -805,7 +805,7 @@ static int do_mprotect_pkey(unsigned long start, size_t len,
 
 		if (map_deny_write_exec(vma, newflags)) {
 			error = -EACCES;
-			goto out;
+			break;
 		}
 
 		/* Allow architectures to sanity-check the new flags */
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index ac1fc986af44..7136c36c5d01 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1398,6 +1398,7 @@ static __always_inline bool free_pages_prepare(struct page *page,
 			unsigned int order, bool check_free, fpi_t fpi_flags)
 {
 	int bad = 0;
+	bool skip_kasan_poison = should_skip_kasan_poison(page, fpi_flags);
 	bool init = want_init_on_free();
 
 	VM_BUG_ON_PAGE(PageTail(page), page);
@@ -1470,7 +1471,7 @@ static __always_inline bool free_pages_prepare(struct page *page,
 	 * With hardware tag-based KASAN, memory tags must be set before the
 	 * page becomes unavailable via debug_pagealloc or arch_free_page.
 	 */
-	if (!should_skip_kasan_poison(page, fpi_flags)) {
+	if (!skip_kasan_poison) {
 		kasan_poison_pages(page, order, init);
 
 		/* Memory is already initialized if KASAN did it internally. */
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index ef910bf349e1..bef6cf2b4d46 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -2883,6 +2883,8 @@ vm_area_alloc_pages(gfp_t gfp, int nid,
 		unsigned int order, unsigned int nr_pages, struct page **pages)
 {
 	unsigned int nr_allocated = 0;
+	gfp_t alloc_gfp = gfp;
+	bool nofail = false;
 	struct page *page;
 	int i;
 
@@ -2893,6 +2895,7 @@ vm_area_alloc_pages(gfp_t gfp, int nid,
 	 * more permissive.
 	 */
 	if (!order) {
+		/* bulk allocator doesn't support nofail req. officially */
 		gfp_t bulk_gfp = gfp & ~__GFP_NOFAIL;
 
 		while (nr_allocated < nr_pages) {
@@ -2931,20 +2934,35 @@ vm_area_alloc_pages(gfp_t gfp, int nid,
 			if (nr != nr_pages_request)
 				break;
 		}
+	} else if (gfp & __GFP_NOFAIL) {
+		/*
+		 * Higher order nofail allocations are really expensive and
+		 * potentially dangerous (pre-mature OOM, disruptive reclaim
+		 * and compaction etc.
+		 */
+		alloc_gfp &= ~__GFP_NOFAIL;
+		nofail = true;
 	}
 
 	/* High-order pages or fallback path if "bulk" fails. */
-
 	while (nr_allocated < nr_pages) {
 		if (fatal_signal_pending(current))
 			break;
 
 		if (nid == NUMA_NO_NODE)
-			page = alloc_pages(gfp, order);
+			page = alloc_pages(alloc_gfp, order);
 		else
-			page = alloc_pages_node(nid, gfp, order);
-		if (unlikely(!page))
-			break;
+			page = alloc_pages_node(nid, alloc_gfp, order);
+		if (unlikely(!page)) {
+			if (!nofail)
+				break;
+
+			/* fall back to the zero order allocations */
+			alloc_gfp |= __GFP_NOFAIL;
+			order = 0;
+			continue;
+		}
+
 		/*
 		 * Higher order allocations must be able to be treated as
 		 * indepdenent small pages by callers (as they can with