1 files changed, 47 insertions, 20 deletions

diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index f5dcd36d3151..0c30d0455de1 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -73,11 +73,11 @@ module_param(lock_stat, int, 0644);
  * to use a raw spinlock - we really dont want the spinlock
  * code to recurse back into the lockdep code...
  */
-static raw_spinlock_t lockdep_lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
+static arch_spinlock_t lockdep_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;
 
 static int graph_lock(void)
 {
-        __raw_spin_lock(&lockdep_lock);
+        arch_spin_lock(&lockdep_lock);
         /*
          * Make sure that if another CPU detected a bug while
          * walking the graph we dont change it (while the other
@@ -85,7 +85,7 @@ static int graph_lock(void)
          * dropped already)
          */
         if (!debug_locks) {
-                __raw_spin_unlock(&lockdep_lock);
+                arch_spin_unlock(&lockdep_lock);
                 return 0;
         }
         /* prevent any recursions within lockdep from causing deadlocks */
@@ -95,11 +95,11 @@ static int graph_lock(void)
 
 static inline int graph_unlock(void)
 {
-        if (debug_locks && !__raw_spin_is_locked(&lockdep_lock))
+        if (debug_locks && !arch_spin_is_locked(&lockdep_lock))
                 return DEBUG_LOCKS_WARN_ON(1);
 
         current->lockdep_recursion--;
-        __raw_spin_unlock(&lockdep_lock);
+        arch_spin_unlock(&lockdep_lock);
         return 0;
 }
 
@@ -111,7 +111,7 @@ static inline int debug_locks_off_graph_unlock(void)
 {
         int ret = debug_locks_off();
 
-        __raw_spin_unlock(&lockdep_lock);
+        arch_spin_unlock(&lockdep_lock);
 
         return ret;
 }
@@ -140,7 +140,8 @@ static inline struct lock_class *hlock_class(struct held_lock *hlock)
 }
 
 #ifdef CONFIG_LOCK_STAT
-static DEFINE_PER_CPU(struct lock_class_stats[MAX_LOCKDEP_KEYS], lock_stats);
+static DEFINE_PER_CPU(struct lock_class_stats[MAX_LOCKDEP_KEYS],
+                      cpu_lock_stats);
 
 static inline u64 lockstat_clock(void)
 {
@@ -168,7 +169,7 @@ static void lock_time_inc(struct lock_time *lt, u64 time)
         if (time > lt->max)
                 lt->max = time;
 
-        if (time < lt->min || !lt->min)
+        if (time < lt->min || !lt->nr)
                 lt->min = time;
 
         lt->total += time;
@@ -177,8 +178,15 @@ static void lock_time_inc(struct lock_time *lt, u64 time)
 
 static inline void lock_time_add(struct lock_time *src, struct lock_time *dst)
 {
-        dst->min += src->min;
-        dst->max += src->max;
+        if (!src->nr)
+                return;
+
+        if (src->max > dst->max)
+                dst->max = src->max;
+
+        if (src->min < dst->min || !dst->nr)
+                dst->min = src->min;
+
         dst->total += src->total;
         dst->nr += src->nr;
 }
@@ -191,7 +199,7 @@ struct lock_class_stats lock_stats(struct lock_class *class)
         memset(&stats, 0, sizeof(struct lock_class_stats));
         for_each_possible_cpu(cpu) {
                 struct lock_class_stats *pcs =
-                        &per_cpu(lock_stats, cpu)[class - lock_classes];
+                        &per_cpu(cpu_lock_stats, cpu)[class - lock_classes];
 
                 for (i = 0; i < ARRAY_SIZE(stats.contention_point); i++)
                         stats.contention_point[i] += pcs->contention_point[i];
@@ -218,7 +226,7 @@ void clear_lock_stats(struct lock_class *class)
 
         for_each_possible_cpu(cpu) {
                 struct lock_class_stats *cpu_stats =
-                        &per_cpu(lock_stats, cpu)[class - lock_classes];
+                        &per_cpu(cpu_lock_stats, cpu)[class - lock_classes];
 
                 memset(cpu_stats, 0, sizeof(struct lock_class_stats));
         }
@@ -228,12 +236,12 @@ void clear_lock_stats(struct lock_class *class)
 
 static struct lock_class_stats *get_lock_stats(struct lock_class *class)
 {
-        return &get_cpu_var(lock_stats)[class - lock_classes];
+        return &get_cpu_var(cpu_lock_stats)[class - lock_classes];
 }
 
 static void put_lock_stats(struct lock_class_stats *stats)
 {
-        put_cpu_var(lock_stats);
+        put_cpu_var(cpu_lock_stats);
 }
 
 static void lock_release_holdtime(struct held_lock *hlock)
@@ -379,7 +387,8 @@ static int save_trace(struct stack_trace *trace)
          * complete trace that maxes out the entries provided will be reported
          * as incomplete, friggin useless </rant>
          */
-        if (trace->entries[trace->nr_entries-1] == ULONG_MAX)
+        if (trace->nr_entries != 0 &&
+            trace->entries[trace->nr_entries-1] == ULONG_MAX)
                 trace->nr_entries--;
 
         trace->max_entries = trace->nr_entries;
@@ -1161,9 +1170,9 @@ unsigned long lockdep_count_forward_deps(struct lock_class *class)
         this.class = class;
 
         local_irq_save(flags);
-        __raw_spin_lock(&lockdep_lock);
+        arch_spin_lock(&lockdep_lock);
         ret = __lockdep_count_forward_deps(&this);
-        __raw_spin_unlock(&lockdep_lock);
+        arch_spin_unlock(&lockdep_lock);
         local_irq_restore(flags);
 
         return ret;
@@ -1188,9 +1197,9 @@ unsigned long lockdep_count_backward_deps(struct lock_class *class)
         this.class = class;
 
         local_irq_save(flags);
-        __raw_spin_lock(&lockdep_lock);
+        arch_spin_lock(&lockdep_lock);
         ret = __lockdep_count_backward_deps(&this);
-        __raw_spin_unlock(&lockdep_lock);
+        arch_spin_unlock(&lockdep_lock);
         local_irq_restore(flags);
 
         return ret;
@@ -2138,7 +2147,7 @@ check_usage_backwards(struct task_struct *curr, struct held_lock *this,
                 return ret;
 
         return print_irq_inversion_bug(curr, &root, target_entry,
-                                        this, 1, irqclass);
+                                        this, 0, irqclass);
 }
 
 void print_irqtrace_events(struct task_struct *curr)
@@ -3800,3 +3809,21 @@ void lockdep_sys_exit(void)
                 lockdep_print_held_locks(curr);
         }
 }
+
+void lockdep_rcu_dereference(const char *file, const int line)
+{
+        struct task_struct *curr = current;
+
+        if (!debug_locks_off())
+                return;
+        printk("\n===================================================\n");
+        printk(  "[ INFO: suspicious rcu_dereference_check() usage. ]\n");
+        printk(  "---------------------------------------------------\n");
+        printk("%s:%d invoked rcu_dereference_check() without protection!\n",
+                        file, line);
+        printk("\nother info that might help us debug this:\n\n");
+        lockdep_print_held_locks(curr);
+        printk("\nstack backtrace:\n");
+        dump_stack();
+}
+EXPORT_SYMBOL_GPL(lockdep_rcu_dereference);