Merge tag 'v4.7-rc2' into v4l_for_linus

Linux 4.7-rc2

* tag 'v4.7-rc2': (10914 commits)
  Linux 4.7-rc2
  devpts: Make each mount of devpts an independent filesystem.
  parisc: Move die_if_kernel() prototype into traps.h header
  parisc: Fix pagefault crash in unaligned __get_user() call
  parisc: Fix printk time during boot
  parisc: Fix backtrace on PA-RISC
  mm, page_alloc: recalculate the preferred zoneref if the context can ignore memory policies
  mm, page_alloc: reset zonelist iterator after resetting fair zone allocation policy
  mm, oom_reaper: do not use siglock in try_oom_reaper()
  mm, page_alloc: prevent infinite loop in buffered_rmqueue()
  checkpatch: reduce git commit description style false positives
  mm/z3fold.c: avoid modifying HEADLESS page and minor cleanup
  memcg: add RCU locking around css_for_each_descendant_pre() in memcg_offline_kmem()
  mm: check the return value of lookup_page_ext for all call sites
  kdump: fix dmesg gdbmacro to work with record based printk
  mm: fix overflow in vm_map_ram()
  Btrfs: deal with duplciates during extent_map insertion in btrfs_get_extent
  arm64: fix alignment when RANDOMIZE_TEXT_OFFSET is enabled
  arm64: move {PAGE,CONT}_SHIFT into Kconfig
  arm64: mm: dump: log span level
  ...

1 files changed, 24 insertions, 39 deletions

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 3bfdff06eea7..e1c0e996b5ae 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -433,54 +433,28 @@ static void *work_debug_hint(void *addr)
 	return ((struct work_struct *) addr)->func;
 }
 
-/*
- * fixup_init is called when:
- * - an active object is initialized
- */
-static int work_fixup_init(void *addr, enum debug_obj_state state)
+static bool work_is_static_object(void *addr)
 {
 	struct work_struct *work = addr;
 
-	switch (state) {
-	case ODEBUG_STATE_ACTIVE:
-		cancel_work_sync(work);
-		debug_object_init(work, &work_debug_descr);
-		return 1;
-	default:
-		return 0;
-	}
+	return test_bit(WORK_STRUCT_STATIC_BIT, work_data_bits(work));
 }
 
 /*
- * fixup_activate is called when:
- * - an active object is activated
- * - an unknown object is activated (might be a statically initialized object)
+ * fixup_init is called when:
+ * - an active object is initialized
  */
-static int work_fixup_activate(void *addr, enum debug_obj_state state)
+static bool work_fixup_init(void *addr, enum debug_obj_state state)
 {
 	struct work_struct *work = addr;
 
 	switch (state) {
-
-	case ODEBUG_STATE_NOTAVAILABLE:
-		/*
-		 * This is not really a fixup. The work struct was
-		 * statically initialized. We just make sure that it
-		 * is tracked in the object tracker.
-		 */
-		if (test_bit(WORK_STRUCT_STATIC_BIT, work_data_bits(work))) {
-			debug_object_init(work, &work_debug_descr);
-			debug_object_activate(work, &work_debug_descr);
-			return 0;
-		}
-		WARN_ON_ONCE(1);
-		return 0;
-
 	case ODEBUG_STATE_ACTIVE:
-		WARN_ON(1);
-
+		cancel_work_sync(work);
+		debug_object_init(work, &work_debug_descr);
+		return true;
 	default:
-		return 0;
+		return false;
 	}
 }
 
@@ -488,7 +462,7 @@ static int work_fixup_activate(void *addr, enum debug_obj_state state)
  * fixup_free is called when:
  * - an active object is freed
  */
-static int work_fixup_free(void *addr, enum debug_obj_state state)
+static bool work_fixup_free(void *addr, enum debug_obj_state state)
 {
 	struct work_struct *work = addr;
 
@@ -496,17 +470,17 @@ static int work_fixup_free(void *addr, enum debug_obj_state state)
 	case ODEBUG_STATE_ACTIVE:
 		cancel_work_sync(work);
 		debug_object_free(work, &work_debug_descr);
-		return 1;
+		return true;
 	default:
-		return 0;
+		return false;
 	}
 }
 
 static struct debug_obj_descr work_debug_descr = {
 	.name		= "work_struct",
 	.debug_hint	= work_debug_hint,
+	.is_static_object = work_is_static_object,
 	.fixup_init	= work_fixup_init,
-	.fixup_activate	= work_fixup_activate,
 	.fixup_free	= work_fixup_free,
 };
 
@@ -4554,6 +4528,17 @@ static void rebind_workers(struct worker_pool *pool)
 						  pool->attrs->cpumask) < 0);
 
 	spin_lock_irq(&pool->lock);
+
+	/*
+	 * XXX: CPU hotplug notifiers are weird and can call DOWN_FAILED
+	 * w/o preceding DOWN_PREPARE.  Work around it.  CPU hotplug is
+	 * being reworked and this can go away in time.
+	 */
+	if (!(pool->flags & POOL_DISASSOCIATED)) {
+		spin_unlock_irq(&pool->lock);
+		return;
+	}
+
 	pool->flags &= ~POOL_DISASSOCIATED;
 
 	for_each_pool_worker(worker, pool) {