Merge branch 'akpm' (patches from Andrew)

Merge fixes from Andrew Morton:
 "11 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  Update maintainers for DRM STI driver
  mm: cma: mark cma_bitmap_maxno() inline in header
  zram: fix pool name truncation
  memory-hotplug: fix wrong edge when hot add a new node
  .mailmap: Andrey Ryabinin has moved
  ipc/sem.c: update/correct memory barriers
  mm/hwpoison: fix panic due to split huge zero page
  ipc,sem: remove uneeded sem_undo_list lock usage in exit_sem()
  ipc,sem: fix use after free on IPC_RMID after a task using same semaphore set exits
  mm/hwpoison: fix fail isolate hugetlbfs page w/ refcount held
  mm/hwpoison: fix page refcount of unknown non LRU page

.mailmap

@@ -17,6 +17,7 @@ Aleksey Gorelov <aleksey_gorelov@phoenix.com>
 Al Viro <viro@ftp.linux.org.uk>
 Al Viro <viro@zenIV.linux.org.uk>
 Andreas Herrmann <aherrman@de.ibm.com>
+Andrey Ryabinin <ryabinin.a.a@gmail.com> <a.ryabinin@samsung.com>
 Andrew Morton <akpm@linux-foundation.org>
 Andrew Vasquez <andrew.vasquez@qlogic.com>
 Andy Adamson <andros@citi.umich.edu>

MAINTAINERS

@@ -3587,6 +3587,15 @@ S:	Maintained
 F:	drivers/gpu/drm/rockchip/
 F:	Documentation/devicetree/bindings/video/rockchip*
 
+DRM DRIVERS FOR STI
+M:	Benjamin Gaignard <benjamin.gaignard@linaro.org>
+M:	Vincent Abriou <vincent.abriou@st.com>
+L:	dri-devel@lists.freedesktop.org
+T:	git http://git.linaro.org/people/benjamin.gaignard/kernel.git
+S:	Maintained
+F:	drivers/gpu/drm/sti
+F:	Documentation/devicetree/bindings/gpu/st,stih4xx.txt
+
 DSBR100 USB FM RADIO DRIVER
 M:	Alexey Klimov <klimov.linux@gmail.com>
 L:	linux-media@vger.kernel.org

drivers/block/zram/zram_drv.c

@@ -496,10 +496,9 @@ static void zram_meta_free(struct zram_meta *meta, u64 disksize)
 	kfree(meta);
 }
 
-static struct zram_meta *zram_meta_alloc(int device_id, u64 disksize)
+static struct zram_meta *zram_meta_alloc(char *pool_name, u64 disksize)
 {
 	size_t num_pages;
-	char pool_name[8];
 	struct zram_meta *meta = kmalloc(sizeof(*meta), GFP_KERNEL);
 
 	if (!meta)
@@ -512,7 +511,6 @@ static struct zram_meta *zram_meta_alloc(int device_id, u64 disksize)
 		goto out_error;
 	}
 
-	snprintf(pool_name, sizeof(pool_name), "zram%d", device_id);
 	meta->mem_pool = zs_create_pool(pool_name, GFP_NOIO | __GFP_HIGHMEM);
 	if (!meta->mem_pool) {
 		pr_err("Error creating memory pool\n");
@@ -1031,7 +1029,7 @@ static ssize_t disksize_store(struct device *dev,
 		return -EINVAL;
 
 	disksize = PAGE_ALIGN(disksize);
-	meta = zram_meta_alloc(zram->disk->first_minor, disksize);
+	meta = zram_meta_alloc(zram->disk->disk_name, disksize);
 	if (!meta)
 		return -ENOMEM;
 

ipc/sem.c

@@ -252,6 +252,16 @@ static void sem_rcu_free(struct rcu_head *head)
 	ipc_rcu_free(head);
 }
 
+/*
+ * spin_unlock_wait() and !spin_is_locked() are not memory barriers, they
+ * are only control barriers.
+ * The code must pair with spin_unlock(&sem->lock) or
+ * spin_unlock(&sem_perm.lock), thus just the control barrier is insufficient.
+ *
+ * smp_rmb() is sufficient, as writes cannot pass the control barrier.
+ */
+#define ipc_smp_acquire__after_spin_is_unlocked()	smp_rmb()
+
 /*
  * Wait until all currently ongoing simple ops have completed.
  * Caller must own sem_perm.lock.
@@ -275,6 +285,7 @@ static void sem_wait_array(struct sem_array *sma)
 		sem = sma->sem_base + i;
 		spin_unlock_wait(&sem->lock);
 	}
+	ipc_smp_acquire__after_spin_is_unlocked();
 }
 
 /*
@@ -327,13 +338,12 @@ static inline int sem_lock(struct sem_array *sma, struct sembuf *sops,
 		/* Then check that the global lock is free */
 		if (!spin_is_locked(&sma->sem_perm.lock)) {
 			/*
-			 * The ipc object lock check must be visible on all
-			 * cores before rechecking the complex count.  Otherwise
-			 * we can race with  another thread that does:
+			 * We need a memory barrier with acquire semantics,
+			 * otherwise we can race with another thread that does:
 			 *	complex_count++;
 			 *	spin_unlock(sem_perm.lock);
 			 */
-			smp_rmb();
+			ipc_smp_acquire__after_spin_is_unlocked();
 
 			/*
 			 * Now repeat the test of complex_count:
@@ -2074,17 +2084,28 @@ void exit_sem(struct task_struct *tsk)
 		rcu_read_lock();
 		un = list_entry_rcu(ulp->list_proc.next,
 				    struct sem_undo, list_proc);
-		if (&un->list_proc == &ulp->list_proc)
-			semid = -1;
-		 else
-			semid = un->semid;
-
-		if (semid == -1) {
+		if (&un->list_proc == &ulp->list_proc) {
+			/*
+			 * We must wait for freeary() before freeing this ulp,
+			 * in case we raced with last sem_undo. There is a small
+			 * possibility where we exit while freeary() didn't
+			 * finish unlocking sem_undo_list.
+			 */
+			spin_unlock_wait(&ulp->lock);
 			rcu_read_unlock();
 			break;
 		}
+		spin_lock(&ulp->lock);
+		semid = un->semid;
+		spin_unlock(&ulp->lock);
 
-		sma = sem_obtain_object_check(tsk->nsproxy->ipc_ns, un->semid);
+		/* exit_sem raced with IPC_RMID, nothing to do */
+		if (semid == -1) {
+			rcu_read_unlock();
+			continue;
+		}
+
+		sma = sem_obtain_object_check(tsk->nsproxy->ipc_ns, semid);
 		/* exit_sem raced with IPC_RMID, nothing to do */
 		if (IS_ERR(sma)) {
 			rcu_read_unlock();
@@ -2112,9 +2133,11 @@ void exit_sem(struct task_struct *tsk)
 		ipc_assert_locked_object(&sma->sem_perm);
 		list_del(&un->list_id);
 
-		spin_lock(&ulp->lock);
+		/* we are the last process using this ulp, acquiring ulp->lock
+		 * isn't required. Besides that, we are also protected against
+		 * IPC_RMID as we hold sma->sem_perm lock now
+		 */
 		list_del_rcu(&un->list_proc);
-		spin_unlock(&ulp->lock);
 
 		/* perform adjustments registered in un */
 		for (i = 0; i < sma->sem_nsems; i++) {

mm/cma.h

@@ -16,7 +16,7 @@ struct cma {
 extern struct cma cma_areas[MAX_CMA_AREAS];
 extern unsigned cma_area_count;
 
-static unsigned long cma_bitmap_maxno(struct cma *cma)
+static inline unsigned long cma_bitmap_maxno(struct cma *cma)
 {
 	return cma->count >> cma->order_per_bit;
 }

mm/kasan/kasan.c

@@ -2,7 +2,7 @@
  * This file contains shadow memory manipulation code.
  *
  * Copyright (c) 2014 Samsung Electronics Co., Ltd.
- * Author: Andrey Ryabinin <a.ryabinin@samsung.com>
+ * Author: Andrey Ryabinin <ryabinin.a.a@gmail.com>
  *
  * Some of code borrowed from https://github.com/xairy/linux by
  *        Andrey Konovalov <adech.fo@gmail.com>

mm/kasan/report.c

@@ -2,7 +2,7 @@
  * This file contains error reporting code.
  *
  * Copyright (c) 2014 Samsung Electronics Co., Ltd.
- * Author: Andrey Ryabinin <a.ryabinin@samsung.com>
+ * Author: Andrey Ryabinin <ryabinin.a.a@gmail.com>
  *
  * Some of code borrowed from https://github.com/xairy/linux by
  *        Andrey Konovalov <adech.fo@gmail.com>

mm/memory-failure.c

@@ -1146,8 +1146,11 @@ int memory_failure(unsigned long pfn, int trapno, int flags)
 	}
 
 	if (!PageHuge(p) && PageTransHuge(hpage)) {
-		if (unlikely(split_huge_page(hpage))) {
-			pr_err("MCE: %#lx: thp split failed\n", pfn);
+		if (!PageAnon(hpage) || unlikely(split_huge_page(hpage))) {
+			if (!PageAnon(hpage))
+				pr_err("MCE: %#lx: non anonymous thp\n", pfn);
+			else
+				pr_err("MCE: %#lx: thp split failed\n", pfn);
 			if (TestClearPageHWPoison(p))
 				atomic_long_sub(nr_pages, &num_poisoned_pages);
 			put_page(p);
@@ -1538,6 +1541,8 @@ static int get_any_page(struct page *page, unsigned long pfn, int flags)
 		 */
 		ret = __get_any_page(page, pfn, 0);
 		if (!PageLRU(page)) {
+			/* Drop page reference which is from __get_any_page() */
+			put_page(page);
 			pr_info("soft_offline: %#lx: unknown non LRU page type %lx\n",
 				pfn, page->flags);
 			return -EIO;
@@ -1567,13 +1572,12 @@ static int soft_offline_huge_page(struct page *page, int flags)
 	unlock_page(hpage);
 
 	ret = isolate_huge_page(hpage, &pagelist);
-	if (ret) {
-		/*
-		 * get_any_page() and isolate_huge_page() takes a refcount each,
-		 * so need to drop one here.
-		 */
-		put_page(hpage);
-	} else {
+	/*
+	 * get_any_page() and isolate_huge_page() takes a refcount each,
+	 * so need to drop one here.
+	 */
+	put_page(hpage);
+	if (!ret) {
 		pr_info("soft offline: %#lx hugepage failed to isolate\n", pfn);
 		return -EBUSY;
 	}

mm/memory_hotplug.c

@@ -1277,6 +1277,7 @@ int __ref add_memory(int nid, u64 start, u64 size)
 
 	/* create new memmap entry */
 	firmware_map_add_hotplug(start, start + size, "System RAM");
+	memblock_add_node(start, size, nid);
 
 	goto out;
 
@@ -2013,6 +2014,8 @@ void __ref remove_memory(int nid, u64 start, u64 size)
 
 	/* remove memmap entry */
 	firmware_map_remove(start, start + size, "System RAM");
+	memblock_free(start, size);
+	memblock_remove(start, size);
 
 	arch_remove_memory(start, size);
 

mm/page_alloc.c

@@ -5060,6 +5060,10 @@ static unsigned long __meminit zone_spanned_pages_in_node(int nid,
 {
 	unsigned long zone_start_pfn, zone_end_pfn;
 
+	/* When hotadd a new node, the node should be empty */
+	if (!node_start_pfn && !node_end_pfn)
+		return 0;
+
 	/* Get the start and end of the zone */
 	zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type];
 	zone_end_pfn = arch_zone_highest_possible_pfn[zone_type];
@@ -5123,6 +5127,10 @@ static unsigned long __meminit zone_absent_pages_in_node(int nid,
 	unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type];
 	unsigned long zone_start_pfn, zone_end_pfn;
 
+	/* When hotadd a new node, the node should be empty */
+	if (!node_start_pfn && !node_end_pfn)
+		return 0;
+
 	zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high);
 	zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high);