Merge branch 'akpm' (patches from Andrew)

Merge fixes from Andrew Morton:
 "6 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  drivers core: remove assert_held_device_hotplug()
  mm: add private lock to serialize memory hotplug operations
  mm: don't warn when vmalloc() fails due to a fatal signal
  mm, x86: fix native_pud_clear build error
  kasan: add a prototype of task_struct to avoid warning
  z3fold: fix spinlock unlocking in page reclaim

arch/x86/include/asm/pgtable-3level.h

@@ -121,12 +121,9 @@ static inline void native_pmd_clear(pmd_t *pmd)
 	*(tmp + 1) = 0;
 }
 
-#if !defined(CONFIG_SMP) || (defined(CONFIG_HIGHMEM64G) && \
-		defined(CONFIG_PARAVIRT))
 static inline void native_pud_clear(pud_t *pudp)
 {
 }
-#endif
 
 static inline void pud_clear(pud_t *pudp)
 {

arch/x86/include/asm/pgtable.h

@@ -62,7 +62,7 @@ extern struct mm_struct *pgd_page_get_mm(struct page *page);
 # define set_pud(pudp, pud)		native_set_pud(pudp, pud)
 #endif
 
-#ifndef __PAGETABLE_PMD_FOLDED
+#ifndef __PAGETABLE_PUD_FOLDED
 #define pud_clear(pud)			native_pud_clear(pud)
 #endif
 

drivers/base/core.c

@@ -639,11 +639,6 @@ int lock_device_hotplug_sysfs(void)
 	return restart_syscall();
 }
 
-void assert_held_device_hotplug(void)
-{
-	lockdep_assert_held(&device_hotplug_lock);
-}
-
 #ifdef CONFIG_BLOCK
 static inline int device_is_not_partition(struct device *dev)
 {

include/linux/device.h

@@ -1140,7 +1140,6 @@ static inline bool device_supports_offline(struct device *dev)
 extern void lock_device_hotplug(void);
 extern void unlock_device_hotplug(void);
 extern int lock_device_hotplug_sysfs(void);
-void assert_held_device_hotplug(void);
 extern int device_offline(struct device *dev);
 extern int device_online(struct device *dev);
 extern void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode);

include/linux/kasan.h

@@ -6,6 +6,7 @@
 struct kmem_cache;
 struct page;
 struct vm_struct;
+struct task_struct;
 
 #ifdef CONFIG_KASAN
 

kernel/memremap.c

@@ -247,11 +247,9 @@ static void devm_memremap_pages_release(struct device *dev, void *data)
 	align_start = res->start & ~(SECTION_SIZE - 1);
 	align_size = ALIGN(resource_size(res), SECTION_SIZE);
 
-	lock_device_hotplug();
 	mem_hotplug_begin();
 	arch_remove_memory(align_start, align_size);
 	mem_hotplug_done();
-	unlock_device_hotplug();
 
 	untrack_pfn(NULL, PHYS_PFN(align_start), align_size);
 	pgmap_radix_release(res);
@@ -364,11 +362,9 @@ void *devm_memremap_pages(struct device *dev, struct resource *res,
 	if (error)
 		goto err_pfn_remap;
 
-	lock_device_hotplug();
 	mem_hotplug_begin();
 	error = arch_add_memory(nid, align_start, align_size, true);
 	mem_hotplug_done();
-	unlock_device_hotplug();
 	if (error)
 		goto err_add_memory;
 

mm/memory_hotplug.c

@@ -125,9 +125,12 @@ void put_online_mems(void)
 
 }
 
+/* Serializes write accesses to mem_hotplug.active_writer. */
+static DEFINE_MUTEX(memory_add_remove_lock);
+
 void mem_hotplug_begin(void)
 {
-	assert_held_device_hotplug();
+	mutex_lock(&memory_add_remove_lock);
 
 	mem_hotplug.active_writer = current;
 
@@ -147,6 +150,7 @@ void mem_hotplug_done(void)
 	mem_hotplug.active_writer = NULL;
 	mutex_unlock(&mem_hotplug.lock);
 	memhp_lock_release();
+	mutex_unlock(&memory_add_remove_lock);
 }
 
 /* add this memory to iomem resource */

mm/vmalloc.c

@@ -1683,7 +1683,7 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
 
 		if (fatal_signal_pending(current)) {
 			area->nr_pages = i;
-			goto fail;
+			goto fail_no_warn;
 		}
 
 		if (node == NUMA_NO_NODE)
@@ -1709,6 +1709,7 @@ fail:
 	warn_alloc(gfp_mask, NULL,
 			  "vmalloc: allocation failure, allocated %ld of %ld bytes",
 			  (area->nr_pages*PAGE_SIZE), area->size);
+fail_no_warn:
 	vfree(area->addr);
 	return NULL;
 }

mm/z3fold.c

@@ -667,6 +667,7 @@ next:
 			z3fold_page_unlock(zhdr);
 			spin_lock(&pool->lock);
 			if (kref_put(&zhdr->refcount, release_z3fold_page)) {
+				spin_unlock(&pool->lock);
 				atomic64_dec(&pool->pages_nr);
 				return 0;
 			}