Merge branch 'akpm' (patches from Andrew)

Merge fixes from Andrew Morton:
 "7 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  proc: add Alexey to MAINTAINERS
  kasan: depend on CONFIG_SLUB_DEBUG
  include/linux/dax.h: dax_iomap_fault() returns vm_fault_t
  x86/e820: put !E820_TYPE_RAM regions into memblock.reserved
  slub: fix failure when we delete and create a slab cache
  Revert mm/vmstat.c: fix vmstat_update() preemption BUG
  lib/percpu_ida.c: don't do alloc from per-CPU list if there is none

MAINTAINERS

@@ -11481,6 +11481,15 @@ W:	http://wireless.kernel.org/en/users/Drivers/p54
 S:	Obsolete
 F:	drivers/net/wireless/intersil/prism54/
 
+PROC FILESYSTEM
+R:	Alexey Dobriyan <adobriyan@gmail.com>
+L:	linux-kernel@vger.kernel.org
+L:	linux-fsdevel@vger.kernel.org
+S:	Maintained
+F:	fs/proc/
+F:	include/linux/proc_fs.h
+F:	tools/testing/selftests/proc/
+
 PROC SYSCTL
 M:	"Luis R. Rodriguez" <mcgrof@kernel.org>
 M:	Kees Cook <keescook@chromium.org>

arch/x86/kernel/e820.c

@@ -1248,6 +1248,7 @@ void __init e820__memblock_setup(void)
 {
 	int i;
 	u64 end;
+	u64 addr = 0;
 
 	/*
 	 * The bootstrap memblock region count maximum is 128 entries
@@ -1264,13 +1265,21 @@ void __init e820__memblock_setup(void)
 		struct e820_entry *entry = &e820_table->entries[i];
 
 		end = entry->addr + entry->size;
+		if (addr < entry->addr)
+			memblock_reserve(addr, entry->addr - addr);
+		addr = end;
 		if (end != (resource_size_t)end)
 			continue;
 
+		/*
+		 * all !E820_TYPE_RAM ranges (including gap ranges) are put
+		 * into memblock.reserved to make sure that struct pages in
+		 * such regions are not left uninitialized after bootup.
+		 */
 		if (entry->type != E820_TYPE_RAM && entry->type != E820_TYPE_RESERVED_KERN)
-			continue;
-
-		memblock_add(entry->addr, entry->size);
+			memblock_reserve(entry->addr, entry->size);
+		else
+			memblock_add(entry->addr, entry->size);
 	}
 
 	/* Throw away partial pages: */

include/linux/dax.h

@@ -135,7 +135,7 @@ void dax_flush(struct dax_device *dax_dev, void *addr, size_t size);
 
 ssize_t dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter,
 		const struct iomap_ops *ops);
-int dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
+vm_fault_t dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
 		    pfn_t *pfnp, int *errp, const struct iomap_ops *ops);
 vm_fault_t dax_finish_sync_fault(struct vm_fault *vmf,
 		enum page_entry_size pe_size, pfn_t pfn);

include/linux/slub_def.h

@@ -155,8 +155,12 @@ struct kmem_cache {
 
 #ifdef CONFIG_SYSFS
 #define SLAB_SUPPORTS_SYSFS
+void sysfs_slab_unlink(struct kmem_cache *);
 void sysfs_slab_release(struct kmem_cache *);
 #else
+static inline void sysfs_slab_unlink(struct kmem_cache *s)
+{
+}
 static inline void sysfs_slab_release(struct kmem_cache *s)
 {
 }

lib/Kconfig.kasan

@@ -6,6 +6,7 @@ if HAVE_ARCH_KASAN
 config KASAN
 	bool "KASan: runtime memory debugger"
 	depends on SLUB || (SLAB && !DEBUG_SLAB)
+	select SLUB_DEBUG if SLUB
 	select CONSTRUCTORS
 	select STACKDEPOT
 	help

lib/percpu_ida.c

@@ -141,7 +141,7 @@ int percpu_ida_alloc(struct percpu_ida *pool, int state)
 	spin_lock_irqsave(&tags->lock, flags);
 
 	/* Fastpath */
-	if (likely(tags->nr_free >= 0)) {
+	if (likely(tags->nr_free)) {
 		tag = tags->freelist[--tags->nr_free];
 		spin_unlock_irqrestore(&tags->lock, flags);
 		return tag;

mm/slab_common.c

@@ -567,10 +567,14 @@ static int shutdown_cache(struct kmem_cache *s)
 	list_del(&s->list);
 
 	if (s->flags & SLAB_TYPESAFE_BY_RCU) {
+#ifdef SLAB_SUPPORTS_SYSFS
+		sysfs_slab_unlink(s);
+#endif
 		list_add_tail(&s->list, &slab_caches_to_rcu_destroy);
 		schedule_work(&slab_caches_to_rcu_destroy_work);
 	} else {
 #ifdef SLAB_SUPPORTS_SYSFS
+		sysfs_slab_unlink(s);
 		sysfs_slab_release(s);
 #else
 		slab_kmem_cache_release(s);

mm/slub.c

@@ -5667,7 +5667,6 @@ static void sysfs_slab_remove_workfn(struct work_struct *work)
 	kset_unregister(s->memcg_kset);
 #endif
 	kobject_uevent(&s->kobj, KOBJ_REMOVE);
-	kobject_del(&s->kobj);
 out:
 	kobject_put(&s->kobj);
 }
@@ -5752,6 +5751,12 @@ static void sysfs_slab_remove(struct kmem_cache *s)
 	schedule_work(&s->kobj_remove_work);
 }
 
+void sysfs_slab_unlink(struct kmem_cache *s)
+{
+	if (slab_state >= FULL)
+		kobject_del(&s->kobj);
+}
+
 void sysfs_slab_release(struct kmem_cache *s)
 {
 	if (slab_state >= FULL)

mm/vmstat.c

@@ -1796,11 +1796,9 @@ static void vmstat_update(struct work_struct *w)
 		 * to occur in the future. Keep on running the
 		 * update worker thread.
 		 */
-		preempt_disable();
 		queue_delayed_work_on(smp_processor_id(), mm_percpu_wq,
 				this_cpu_ptr(&vmstat_work),
 				round_jiffies_relative(sysctl_stat_interval));
-		preempt_enable();
 	}
 }