Merge branch 'akpm' (patches from Andrew)

Merge fixes from Andrew Morton:
 "25 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (25 commits)
  lib/decompress: set the compressor name to NULL on error
  mm/cma_debug: correct size input to bitmap function
  mm/cma_debug: fix debugging alloc/free interface
  mm/page_owner: set correct gfp_mask on page_owner
  mm/page_owner: fix possible access violation
  fsnotify: fix oops in fsnotify_clear_marks_by_group_flags()
  /proc/$PID/cmdline: fixup empty ARGV case
  dma-debug: skip debug_dma_assert_idle() when disabled
  hexdump: fix for non-aligned buffers
  checkpatch: fix long line messages about patch context
  mm: clean up per architecture MM hook header files
  MAINTAINERS: uclinux-h8-devel is moderated for non-subscribers
  mailmap: update Sudeep Holla's email id
  Update Viresh Kumar's email address
  mm, meminit: suppress unused memory variable warning
  configfs: fix kernel infoleak through user-controlled format string
  include, lib: add __printf attributes to several function prototypes
  s390/hugetlb: add hugepages_supported define
  mm: hugetlb: allow hugepages_supported to be architecture specific
  revert "s390/mm: make hugepages_supported a boot time decision"
  ...

4 files changed, 27 insertions, 22 deletions

diff --git a/fs/configfs/item.c b/fs/configfs/item.c
index 4d6a30e76168..b863a09cd2f1 100644
--- a/fs/configfs/item.c
+++ b/fs/configfs/item.c
@@ -115,7 +115,7 @@ void config_item_init_type_name(struct config_item *item,
 				const char *name,
 				struct config_item_type *type)
 {
-	config_item_set_name(item, name);
+	config_item_set_name(item, "%s", name);
 	item->ci_type = type;
 	config_item_init(item);
 }
@@ -124,7 +124,7 @@ EXPORT_SYMBOL(config_item_init_type_name);
 void config_group_init_type_name(struct config_group *group, const char *name,
 			 struct config_item_type *type)
 {
-	config_item_set_name(&group->cg_item, name);
+	config_item_set_name(&group->cg_item, "%s", name);
 	group->cg_item.ci_type = type;
 	config_group_init(group);
 }
diff --git a/fs/notify/mark.c b/fs/notify/mark.c
index 92e48c70f0f0..3e594ce41010 100644
--- a/fs/notify/mark.c
+++ b/fs/notify/mark.c
@@ -152,31 +152,15 @@ void fsnotify_destroy_mark_locked(struct fsnotify_mark *mark,
 		BUG();
 
 	list_del_init(&mark->g_list);
-
 	spin_unlock(&mark->lock);
 
 	if (inode && (mark->flags & FSNOTIFY_MARK_FLAG_OBJECT_PINNED))
 		iput(inode);
-	/* release lock temporarily */
-	mutex_unlock(&group->mark_mutex);
 
 	spin_lock(&destroy_lock);
 	list_add(&mark->g_list, &destroy_list);
 	spin_unlock(&destroy_lock);
 	wake_up(&destroy_waitq);
-	/*
-	 * We don't necessarily have a ref on mark from caller so the above destroy
-	 * may have actually freed it, unless this group provides a 'freeing_mark'
-	 * function which must be holding a reference.
-	 */
-
-	/*
-	 * Some groups like to know that marks are being freed.  This is a
-	 * callback to the group function to let it know that this mark
-	 * is being freed.
-	 */
-	if (group->ops->freeing_mark)
-		group->ops->freeing_mark(mark, group);
 
 	/*
 	 * __fsnotify_update_child_dentry_flags(inode);
@@ -191,8 +175,6 @@ void fsnotify_destroy_mark_locked(struct fsnotify_mark *mark,
 	 */
 
 	atomic_dec(&group->num_marks);
-
-	mutex_lock_nested(&group->mark_mutex, SINGLE_DEPTH_NESTING);
 }
 
 void fsnotify_destroy_mark(struct fsnotify_mark *mark,
@@ -205,7 +187,10 @@ void fsnotify_destroy_mark(struct fsnotify_mark *mark,
 
 /*
  * Destroy all marks in the given list. The marks must be already detached from
- * the original inode / vfsmount.
+ * the original inode / vfsmount. Note that we can race with
+ * fsnotify_clear_marks_by_group_flags(). However we hold a reference to each
+ * mark so they won't get freed from under us and nobody else touches our
+ * free_list list_head.
  */
 void fsnotify_destroy_marks(struct list_head *to_free)
 {
@@ -406,7 +391,7 @@ struct fsnotify_mark *fsnotify_find_mark(struct hlist_head *head,
 }
 
 /*
- * clear any marks in a group in which mark->flags & flags is true
+ * Clear any marks in a group in which mark->flags & flags is true.
  */
 void fsnotify_clear_marks_by_group_flags(struct fsnotify_group *group,
 					 unsigned int flags)
@@ -460,6 +445,7 @@ static int fsnotify_mark_destroy(void *ignored)
 {
 	struct fsnotify_mark *mark, *next;
 	struct list_head private_destroy_list;
+	struct fsnotify_group *group;
 
 	for (;;) {
 		spin_lock(&destroy_lock);
@@ -471,6 +457,14 @@ static int fsnotify_mark_destroy(void *ignored)
 
 		list_for_each_entry_safe(mark, next, &private_destroy_list, g_list) {
 			list_del_init(&mark->g_list);
+			group = mark->group;
+			/*
+			 * Some groups like to know that marks are being freed.
+			 * This is a callback to the group function to let it
+			 * know that this mark is being freed.
+			 */
+			if (group && group->ops->freeing_mark)
+				group->ops->freeing_mark(mark, group);
 			fsnotify_put_mark(mark);
 		}
 
diff --git a/fs/proc/Kconfig b/fs/proc/Kconfig
index d751fcb637bb..1ade1206bb89 100644
--- a/fs/proc/Kconfig
+++ b/fs/proc/Kconfig
@@ -75,3 +75,9 @@ config PROC_PAGE_MONITOR
 config PROC_CHILDREN
 	bool "Include /proc/<pid>/task/<tid>/children file"
 	default n
+	help
+	  Provides a fast way to retrieve first level children pids of a task. See
+	  <file:Documentation/filesystems/proc.txt> for more information.
+
+	  Say Y if you are running any user-space software which takes benefit from
+	  this interface. For example, rkt is such a piece of software.
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 87782e874b6a..aa50d1ac28fc 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -243,6 +243,11 @@ static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf,
 	len1 = arg_end - arg_start;
 	len2 = env_end - env_start;
 
+	/* Empty ARGV. */
+	if (len1 == 0) {
+		rv = 0;
+		goto out_free_page;
+	}
 	/*
 	 * Inherently racy -- command line shares address space
 	 * with code and data.