[GIT pull] locking fixes for 5.1

[Thomas Gleixner]

Linus,

please pull the latest locking-urgent-for-linus git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git 
locking-urgent-for-linus

A few fixes for lockdep:

 - Initialize lockdep internal RCU head after initializing RCU

 - Prevent use after free in a alloc_workqueue() error handling path

 - Plug a memory leak in the workqueue core which fails to free a
   dynamically allocated lock name.

 - Make Clang happy


Thanks,

        tglx

------------------>
Arnd Bergmann (1):
      locking/lockdep: Avoid a Clang warning

Bart Van Assche (2):
      locking/lockdep: Only call init_rcu_head() after RCU has been initialized
      workqueue, lockdep: Fix an alloc_workqueue() error path

Qian Cai (1):
      workqueue, lockdep: Fix a memory leak in wq->lock_name


 kernel/locking/lockdep.c | 19 ++++++++++++++-----
 kernel/workqueue.c       |  4 ++++
 2 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 21cb81fe6359..34cdcbedda49 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -842,7 +842,9 @@ static bool class_lock_list_valid(struct lock_class *c, 
struct list_head *h)
        return true;
 }
 
-static u16 chain_hlocks[];
+#ifdef CONFIG_PROVE_LOCKING
+static u16 chain_hlocks[MAX_LOCKDEP_CHAIN_HLOCKS];
+#endif
 
 static bool check_lock_chain_key(struct lock_chain *chain)
 {
@@ -980,15 +982,22 @@ static inline void check_data_structures(void) { }
  */
 static void init_data_structures_once(void)
 {
-       static bool initialization_happened;
+       static bool ds_initialized, rcu_head_initialized;
        int i;
 
-       if (likely(initialization_happened))
+       if (likely(rcu_head_initialized))
+               return;
+
+       if (system_state >= SYSTEM_SCHEDULING) {
+               init_rcu_head(&delayed_free.rcu_head);
+               rcu_head_initialized = true;
+       }
+
+       if (ds_initialized)
                return;
 
-       initialization_happened = true;
+       ds_initialized = true;
 
-       init_rcu_head(&delayed_free.rcu_head);
        INIT_LIST_HEAD(&delayed_free.pf[0].zapped);
        INIT_LIST_HEAD(&delayed_free.pf[1].zapped);
 
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index e163e7a7f5e5..e14da4f599ab 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -3348,6 +3348,8 @@ static void wq_init_lockdep(struct workqueue_struct *wq)
        lock_name = kasprintf(GFP_KERNEL, "%s%s", "(wq_completion)", wq->name);
        if (!lock_name)
                lock_name = wq->name;
+
+       wq->lock_name = lock_name;
        lockdep_init_map(&wq->lockdep_map, lock_name, &wq->key, 0);
 }
 
@@ -4194,6 +4196,8 @@ struct workqueue_struct *alloc_workqueue(const char *fmt,
        return wq;
 
 err_free_wq:
+       wq_unregister_lockdep(wq);
+       wq_free_lockdep(wq);
        free_workqueue_attrs(wq->unbound_attrs);
        kfree(wq);
        return NULL;