Merge branch 'akpm' (patches from Andrew)

Merge misc fixes from Andrew Morton:
 "5 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  include/asm-generic/topology.h: guard cpumask_of_node() macro argument
  fs/binfmt_elf.c: allocate initialized memory in fill_thread_core_info()
  mm: remove VM_BUG_ON(PageSlab()) from page_mapcount()
  mm,thp: stop leaking unreleased file pages
  mm/z3fold: silence kmemleak false positives of slots

fs/binfmt_elf.c

@@ -1733,7 +1733,7 @@ static int fill_thread_core_info(struct elf_thread_core_info *t,
 		    (!regset->active || regset->active(t->task, regset) > 0)) {
 			int ret;
 			size_t size = regset_size(t->task, regset);
-			void *data = kmalloc(size, GFP_KERNEL);
+			void *data = kzalloc(size, GFP_KERNEL);
 			if (unlikely(!data))
 				return 0;
 			ret = regset->get(t->task, regset,

include/asm-generic/topology.h

@@ -48,7 +48,7 @@
   #ifdef CONFIG_NEED_MULTIPLE_NODES
     #define cpumask_of_node(node)	((node) == 0 ? cpu_online_mask : cpu_none_mask)
   #else
-    #define cpumask_of_node(node)	((void)node, cpu_online_mask)
+    #define cpumask_of_node(node)	((void)(node), cpu_online_mask)
   #endif
 #endif
 #ifndef pcibus_to_node

include/linux/mm.h

@@ -782,6 +782,11 @@ static inline void *kvcalloc(size_t n, size_t size, gfp_t flags)
 
 extern void kvfree(const void *addr);
 
+/*
+ * Mapcount of compound page as a whole, does not include mapped sub-pages.
+ *
+ * Must be called only for compound pages or any their tail sub-pages.
+ */
 static inline int compound_mapcount(struct page *page)
 {
 	VM_BUG_ON_PAGE(!PageCompound(page), page);
@@ -801,10 +806,16 @@ static inline void page_mapcount_reset(struct page *page)
 
 int __page_mapcount(struct page *page);
 
+/*
+ * Mapcount of 0-order page; when compound sub-page, includes
+ * compound_mapcount().
+ *
+ * Result is undefined for pages which cannot be mapped into userspace.
+ * For example SLAB or special types of pages. See function page_has_type().
+ * They use this place in struct page differently.
+ */
 static inline int page_mapcount(struct page *page)
 {
-	VM_BUG_ON_PAGE(PageSlab(page), page);
-
 	if (unlikely(PageCompound(page)))
 		return __page_mapcount(page);
 	return atomic_read(&page->_mapcount) + 1;

mm/khugepaged.c

@@ -1692,6 +1692,7 @@ static void collapse_file(struct mm_struct *mm,
 		if (page_has_private(page) &&
 		    !try_to_release_page(page, GFP_KERNEL)) {
 			result = SCAN_PAGE_HAS_PRIVATE;
+			putback_lru_page(page);
 			goto out_unlock;
 		}
 

mm/z3fold.c

@@ -43,6 +43,7 @@
 #include <linux/spinlock.h>
 #include <linux/zpool.h>
 #include <linux/magic.h>
+#include <linux/kmemleak.h>
 
 /*
  * NCHUNKS_ORDER determines the internal allocation granularity, effectively
@@ -215,6 +216,8 @@ static inline struct z3fold_buddy_slots *alloc_slots(struct z3fold_pool *pool,
 				 (gfp & ~(__GFP_HIGHMEM | __GFP_MOVABLE)));
 
 	if (slots) {
+		/* It will be freed separately in free_handle(). */
+		kmemleak_not_leak(slots);
 		memset(slots->slot, 0, sizeof(slots->slot));
 		slots->pool = (unsigned long)pool;
 		rwlock_init(&slots->lock);