5 files changed, 58 insertions, 104 deletions

diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index f1e877b79ed8..cfc2f119779a 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -365,7 +365,7 @@ extern void lockdep_trace_alloc(gfp_t mask);
 
 #define lockdep_recursing(tsk)  ((tsk)->lockdep_recursion)
 
-#else /* !LOCKDEP */
+#else /* !CONFIG_LOCKDEP */
 
 static inline void lockdep_off(void)
 {
@@ -479,82 +479,36 @@ static inline void print_irqtrace_events(struct task_struct *curr)
  * on the per lock-class debug mode:
  */
 
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-# ifdef CONFIG_PROVE_LOCKING
-#  define spin_acquire(l, s, t, i)              lock_acquire(l, s, t, 0, 2, NULL, i)
-#  define spin_acquire_nest(l, s, t, n, i)      lock_acquire(l, s, t, 0, 2, n, i)
-# else
-#  define spin_acquire(l, s, t, i)              lock_acquire(l, s, t, 0, 1, NULL, i)
-#  define spin_acquire_nest(l, s, t, n, i)      lock_acquire(l, s, t, 0, 1, NULL, i)
-# endif
-# define spin_release(l, n, i)                  lock_release(l, n, i)
+#ifdef CONFIG_PROVE_LOCKING
+ #define lock_acquire_exclusive(l, s, t, n, i)          lock_acquire(l, s, t, 0, 2, n, i)
+ #define lock_acquire_shared(l, s, t, n, i)             lock_acquire(l, s, t, 1, 2, n, i)
+ #define lock_acquire_shared_recursive(l, s, t, n, i)   lock_acquire(l, s, t, 2, 2, n, i)
 #else
-# define spin_acquire(l, s, t, i)               do { } while (0)
-# define spin_release(l, n, i)                  do { } while (0)
+ #define lock_acquire_exclusive(l, s, t, n, i)          lock_acquire(l, s, t, 0, 1, n, i)
+ #define lock_acquire_shared(l, s, t, n, i)             lock_acquire(l, s, t, 1, 1, n, i)
+ #define lock_acquire_shared_recursive(l, s, t, n, i)   lock_acquire(l, s, t, 2, 1, n, i)
 #endif
 
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-# ifdef CONFIG_PROVE_LOCKING
-#  define rwlock_acquire(l, s, t, i)            lock_acquire(l, s, t, 0, 2, NULL, i)
-#  define rwlock_acquire_read(l, s, t, i)       lock_acquire(l, s, t, 2, 2, NULL, i)
-# else
-#  define rwlock_acquire(l, s, t, i)            lock_acquire(l, s, t, 0, 1, NULL, i)
-#  define rwlock_acquire_read(l, s, t, i)       lock_acquire(l, s, t, 2, 1, NULL, i)
-# endif
-# define rwlock_release(l, n, i)                lock_release(l, n, i)
-#else
-# define rwlock_acquire(l, s, t, i)             do { } while (0)
-# define rwlock_acquire_read(l, s, t, i)        do { } while (0)
-# define rwlock_release(l, n, i)                do { } while (0)
-#endif
+#define spin_acquire(l, s, t, i)                lock_acquire_exclusive(l, s, t, NULL, i)
+#define spin_acquire_nest(l, s, t, n, i)        lock_acquire_exclusive(l, s, t, n, i)
+#define spin_release(l, n, i)                   lock_release(l, n, i)
 
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-# ifdef CONFIG_PROVE_LOCKING
-#  define mutex_acquire(l, s, t, i)             lock_acquire(l, s, t, 0, 2, NULL, i)
-#  define mutex_acquire_nest(l, s, t, n, i)     lock_acquire(l, s, t, 0, 2, n, i)
-# else
-#  define mutex_acquire(l, s, t, i)             lock_acquire(l, s, t, 0, 1, NULL, i)
-#  define mutex_acquire_nest(l, s, t, n, i)     lock_acquire(l, s, t, 0, 1, n, i)
-# endif
-# define mutex_release(l, n, i)                 lock_release(l, n, i)
-#else
-# define mutex_acquire(l, s, t, i)              do { } while (0)
-# define mutex_acquire_nest(l, s, t, n, i)      do { } while (0)
-# define mutex_release(l, n, i)                 do { } while (0)
-#endif
+#define rwlock_acquire(l, s, t, i)              lock_acquire_exclusive(l, s, t, NULL, i)
+#define rwlock_acquire_read(l, s, t, i)         lock_acquire_shared_recursive(l, s, t, NULL, i)
+#define rwlock_release(l, n, i)                 lock_release(l, n, i)
 
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-# ifdef CONFIG_PROVE_LOCKING
-#  define rwsem_acquire(l, s, t, i)             lock_acquire(l, s, t, 0, 2, NULL, i)
-#  define rwsem_acquire_nest(l, s, t, n, i)     lock_acquire(l, s, t, 0, 2, n, i)
-#  define rwsem_acquire_read(l, s, t, i)        lock_acquire(l, s, t, 1, 2, NULL, i)
-# else
-#  define rwsem_acquire(l, s, t, i)             lock_acquire(l, s, t, 0, 1, NULL, i)
-#  define rwsem_acquire_nest(l, s, t, n, i)     lock_acquire(l, s, t, 0, 1, n, i)
-#  define rwsem_acquire_read(l, s, t, i)        lock_acquire(l, s, t, 1, 1, NULL, i)
-# endif
+#define mutex_acquire(l, s, t, i)               lock_acquire_exclusive(l, s, t, NULL, i)
+#define mutex_acquire_nest(l, s, t, n, i)       lock_acquire_exclusive(l, s, t, n, i)
+#define mutex_release(l, n, i)                  lock_release(l, n, i)
+
+#define rwsem_acquire(l, s, t, i)               lock_acquire_exclusive(l, s, t, NULL, i)
+#define rwsem_acquire_nest(l, s, t, n, i)       lock_acquire_exclusive(l, s, t, n, i)
+#define rwsem_acquire_read(l, s, t, i)          lock_acquire_shared(l, s, t, NULL, i)
 # define rwsem_release(l, n, i)                 lock_release(l, n, i)
-#else
-# define rwsem_acquire(l, s, t, i)              do { } while (0)
-# define rwsem_acquire_nest(l, s, t, n, i)      do { } while (0)
-# define rwsem_acquire_read(l, s, t, i)         do { } while (0)
-# define rwsem_release(l, n, i)                 do { } while (0)
-#endif
 
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-# ifdef CONFIG_PROVE_LOCKING
-#  define lock_map_acquire(l)           lock_acquire(l, 0, 0, 0, 2, NULL, _THIS_IP_)
-#  define lock_map_acquire_read(l)      lock_acquire(l, 0, 0, 2, 2, NULL, _THIS_IP_)
-# else
-#  define lock_map_acquire(l)           lock_acquire(l, 0, 0, 0, 1, NULL, _THIS_IP_)
-#  define lock_map_acquire_read(l)      lock_acquire(l, 0, 0, 2, 1, NULL, _THIS_IP_)
-# endif
+#define lock_map_acquire(l)                     lock_acquire_exclusive(l, 0, 0, NULL, _THIS_IP_)
+#define lock_map_acquire_read(l)                lock_acquire_shared_recursive(l, 0, 0, NULL, _THIS_IP_)
 # define lock_map_release(l)                    lock_release(l, 1, _THIS_IP_)
-#else
-# define lock_map_acquire(l)                    do { } while (0)
-# define lock_map_acquire_read(l)               do { } while (0)
-# define lock_map_release(l)                    do { } while (0)
-#endif
 
 #ifdef CONFIG_PROVE_LOCKING
 # define might_lock(lock)                                               \
diff --git a/kernel/hung_task.c b/kernel/hung_task.c
index 6df614912b9d..3e97fb126e6b 100644
--- a/kernel/hung_task.c
+++ b/kernel/hung_task.c
@@ -15,6 +15,7 @@
 #include <linux/lockdep.h>
 #include <linux/export.h>
 #include <linux/sysctl.h>
+#include <linux/utsname.h>
 
 /*
  * The number of tasks checked:
@@ -99,10 +100,14 @@ static void check_hung_task(struct task_struct *t, unsigned long timeout)
          * Ok, the task did not get scheduled for more than 2 minutes,
          * complain:
          */
-        printk(KERN_ERR "INFO: task %s:%d blocked for more than "
-                        "%ld seconds.\n", t->comm, t->pid, timeout);
-        printk(KERN_ERR "\"echo 0 > /proc/sys/kernel/hung_task_timeout_secs\""
-                        " disables this message.\n");
+        pr_err("INFO: task %s:%d blocked for more than %ld seconds.\n",
+                t->comm, t->pid, timeout);
+        pr_err("      %s %s %.*s\n",
+                print_tainted(), init_utsname()->release,
+                (int)strcspn(init_utsname()->version, " "),
+                init_utsname()->version);
+        pr_err("\"echo 0 > /proc/sys/kernel/hung_task_timeout_secs\""
+                " disables this message.\n");
         sched_show_task(t);
         debug_show_held_locks(t);
 
diff --git a/kernel/lglock.c b/kernel/lglock.c
index 6535a667a5a7..86ae2aebf004 100644
--- a/kernel/lglock.c
+++ b/kernel/lglock.c
@@ -21,7 +21,7 @@ void lg_local_lock(struct lglock *lg)
         arch_spinlock_t *lock;
 
         preempt_disable();
-        rwlock_acquire_read(&lg->lock_dep_map, 0, 0, _RET_IP_);
+        lock_acquire_shared(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_);
         lock = this_cpu_ptr(lg->lock);
         arch_spin_lock(lock);
 }
@@ -31,7 +31,7 @@ void lg_local_unlock(struct lglock *lg)
 {
         arch_spinlock_t *lock;
 
-        rwlock_release(&lg->lock_dep_map, 1, _RET_IP_);
+        lock_release(&lg->lock_dep_map, 1, _RET_IP_);
         lock = this_cpu_ptr(lg->lock);
         arch_spin_unlock(lock);
         preempt_enable();
@@ -43,7 +43,7 @@ void lg_local_lock_cpu(struct lglock *lg, int cpu)
         arch_spinlock_t *lock;
 
         preempt_disable();
-        rwlock_acquire_read(&lg->lock_dep_map, 0, 0, _RET_IP_);
+        lock_acquire_shared(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_);
         lock = per_cpu_ptr(lg->lock, cpu);
         arch_spin_lock(lock);
 }
@@ -53,7 +53,7 @@ void lg_local_unlock_cpu(struct lglock *lg, int cpu)
 {
         arch_spinlock_t *lock;
 
-        rwlock_release(&lg->lock_dep_map, 1, _RET_IP_);
+        lock_release(&lg->lock_dep_map, 1, _RET_IP_);
         lock = per_cpu_ptr(lg->lock, cpu);
         arch_spin_unlock(lock);
         preempt_enable();
@@ -65,7 +65,7 @@ void lg_global_lock(struct lglock *lg)
         int i;
 
         preempt_disable();
-        rwlock_acquire(&lg->lock_dep_map, 0, 0, _RET_IP_);
+        lock_acquire_exclusive(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_);
         for_each_possible_cpu(i) {
                 arch_spinlock_t *lock;
                 lock = per_cpu_ptr(lg->lock, i);
@@ -78,7 +78,7 @@ void lg_global_unlock(struct lglock *lg)
 {
         int i;
 
-        rwlock_release(&lg->lock_dep_map, 1, _RET_IP_);
+        lock_release(&lg->lock_dep_map, 1, _RET_IP_);
         for_each_possible_cpu(i) {
                 arch_spinlock_t *lock;
                 lock = per_cpu_ptr(lg->lock, i);
diff --git a/kernel/mutex.c b/kernel/mutex.c
index a52ee7bb830d..6d647aedffea 100644
--- a/kernel/mutex.c
+++ b/kernel/mutex.c
@@ -209,11 +209,13 @@ int mutex_spin_on_owner(struct mutex *lock, struct task_struct *owner)
  */
 static inline int mutex_can_spin_on_owner(struct mutex *lock)
 {
+        struct task_struct *owner;
         int retval = 1;
 
         rcu_read_lock();
-        if (lock->owner)
-                retval = lock->owner->on_cpu;
+        owner = ACCESS_ONCE(lock->owner);
+        if (owner)
+                retval = owner->on_cpu;
         rcu_read_unlock();
         /*
          * if lock->owner is not set, the mutex owner may have just acquired
@@ -461,7 +463,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
                          * performed the optimistic spinning cannot be done.
                          */
                         if (ACCESS_ONCE(ww->ctx))
-                                break;
+                                goto slowpath;
                 }
 
                 /*
@@ -472,7 +474,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
                 owner = ACCESS_ONCE(lock->owner);
                 if (owner && !mutex_spin_on_owner(lock, owner)) {
                         mspin_unlock(MLOCK(lock), &node);
-                        break;
+                        goto slowpath;
                 }
 
                 if ((atomic_read(&lock->count) == 1) &&
@@ -499,7 +501,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
                  * the owner complete.
                  */
                 if (!owner && (need_resched() || rt_task(task)))
-                        break;
+                        goto slowpath;
 
                 /*
                  * The cpu_relax() call is a compiler barrier which forces
@@ -513,6 +515,10 @@ slowpath:
 #endif
         spin_lock_mutex(&lock->wait_lock, flags);
 
+        /* once more, can we acquire the lock? */
+        if (MUTEX_SHOW_NO_WAITER(lock) && (atomic_xchg(&lock->count, 0) == 1))
+                goto skip_wait;
+
         debug_mutex_lock_common(lock, &waiter);
         debug_mutex_add_waiter(lock, &waiter, task_thread_info(task));
 
@@ -520,9 +526,6 @@ slowpath:
         list_add_tail(&waiter.list, &lock->wait_list);
         waiter.task = task;
 
-        if (MUTEX_SHOW_NO_WAITER(lock) && (atomic_xchg(&lock->count, -1) == 1))
-                goto done;
-
         lock_contended(&lock->dep_map, ip);
 
         for (;;) {
@@ -536,7 +539,7 @@ slowpath:
                  * other waiters:
                  */
                 if (MUTEX_SHOW_NO_WAITER(lock) &&
-                   (atomic_xchg(&lock->count, -1) == 1))
+                    (atomic_xchg(&lock->count, -1) == 1))
                         break;
 
                 /*
@@ -561,24 +564,25 @@ slowpath:
                 schedule_preempt_disabled();
                 spin_lock_mutex(&lock->wait_lock, flags);
         }
+        mutex_remove_waiter(lock, &waiter, current_thread_info());
+        /* set it to 0 if there are no waiters left: */
+        if (likely(list_empty(&lock->wait_list)))
+                atomic_set(&lock->count, 0);
+        debug_mutex_free_waiter(&waiter);
 
-done:
+skip_wait:
+        /* got the lock - cleanup and rejoice! */
         lock_acquired(&lock->dep_map, ip);
-        /* got the lock - rejoice! */
-        mutex_remove_waiter(lock, &waiter, current_thread_info());
         mutex_set_owner(lock);
 
         if (!__builtin_constant_p(ww_ctx == NULL)) {
-                struct ww_mutex *ww = container_of(lock,
-                                                      struct ww_mutex,
-                                                      base);
+                struct ww_mutex *ww = container_of(lock, struct ww_mutex, base);
                 struct mutex_waiter *cur;
 
                 /*
                  * This branch gets optimized out for the common case,
                  * and is only important for ww_mutex_lock.
                  */
-
                 ww_mutex_lock_acquired(ww, ww_ctx);
                 ww->ctx = ww_ctx;
 
@@ -592,15 +596,8 @@ done:
                 }
         }
 
-        /* set it to 0 if there are no waiters left: */
-        if (likely(list_empty(&lock->wait_list)))
-                atomic_set(&lock->count, 0);
-
         spin_unlock_mutex(&lock->wait_lock, flags);
-
-        debug_mutex_free_waiter(&waiter);
         preempt_enable();
-
         return 0;
 
 err:
diff --git a/kernel/smp.c b/kernel/smp.c
index fe9f773d7114..b1c9034bdfcb 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -278,8 +278,6 @@ EXPORT_SYMBOL(smp_call_function_single);
  * @wait: If true, wait until function has completed.
  *
  * Returns 0 on success, else a negative status code (if no cpus were online).
- * Note that @wait will be implicitly turned on in case of allocation failures,
- * since we fall back to on-stack allocation.
  *
  * Selection preference:
  *      1) current cpu if in @mask