lockdep: Provide off case for redundant_hardirqs_on increment
[safe/jmp/linux-2.6] / kernel / lockdep.c
index 429540c..9cf7985 100644 (file)
@@ -43,6 +43,7 @@
 #include <linux/ftrace.h>
 #include <linux/stringify.h>
 #include <linux/bitops.h>
+#include <linux/gfp.h>
 
 #include <asm/sections.h>
 
@@ -73,11 +74,11 @@ 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 +86,7 @@ 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 +96,11 @@ 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 +112,7 @@ 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;
 }
@@ -430,20 +431,7 @@ static struct stack_trace lockdep_init_trace = {
 /*
  * Various lockdep statistics:
  */
-atomic_t chain_lookup_hits;
-atomic_t chain_lookup_misses;
-atomic_t hardirqs_on_events;
-atomic_t hardirqs_off_events;
-atomic_t redundant_hardirqs_on;
-atomic_t redundant_hardirqs_off;
-atomic_t softirqs_on_events;
-atomic_t softirqs_off_events;
-atomic_t redundant_softirqs_on;
-atomic_t redundant_softirqs_off;
-atomic_t nr_unused_locks;
-atomic_t nr_cyclic_checks;
-atomic_t nr_find_usage_forwards_checks;
-atomic_t nr_find_usage_backwards_checks;
+DEFINE_PER_CPU(struct lockdep_stats, lockdep_stats);
 #endif
 
 /*
@@ -582,9 +570,6 @@ static int static_obj(void *obj)
        unsigned long start = (unsigned long) &_stext,
                      end   = (unsigned long) &_end,
                      addr  = (unsigned long) obj;
-#ifdef CONFIG_SMP
-       int i;
-#endif
 
        /*
         * static variable?
@@ -595,24 +580,16 @@ static int static_obj(void *obj)
        if (arch_is_kernel_data(addr))
                return 1;
 
-#ifdef CONFIG_SMP
        /*
-        * percpu var?
+        * in-kernel percpu var?
         */
-       for_each_possible_cpu(i) {
-               start = (unsigned long) &__per_cpu_start + per_cpu_offset(i);
-               end   = (unsigned long) &__per_cpu_start + PERCPU_ENOUGH_ROOM
-                                       + per_cpu_offset(i);
-
-               if ((addr >= start) && (addr < end))
-                       return 1;
-       }
-#endif
+       if (is_kernel_percpu_address(addr))
+               return 1;
 
        /*
-        * module var?
+        * module static or percpu var?
         */
-       return is_module_address(addr);
+       return is_module_address(addr) || is_module_percpu_address(addr);
 }
 
 /*
@@ -758,7 +735,7 @@ register_lock_class(struct lockdep_map *lock, unsigned int subclass, int force)
                return NULL;
        }
        class = lock_classes + nr_lock_classes++;
-       debug_atomic_inc(&nr_unused_locks);
+       debug_atomic_inc(nr_unused_locks);
        class->key = key;
        class->name = lock->name;
        class->subclass = subclass;
@@ -1170,9 +1147,9 @@ 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;
@@ -1197,9 +1174,9 @@ 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;
@@ -1215,7 +1192,7 @@ check_noncircular(struct lock_list *root, struct lock_class *target,
 {
        int result;
 
-       debug_atomic_inc(&nr_cyclic_checks);
+       debug_atomic_inc(nr_cyclic_checks);
 
        result = __bfs_forwards(root, target, class_equal, target_entry);
 
@@ -1252,7 +1229,7 @@ find_usage_forwards(struct lock_list *root, enum lock_usage_bit bit,
 {
        int result;
 
-       debug_atomic_inc(&nr_find_usage_forwards_checks);
+       debug_atomic_inc(nr_find_usage_forwards_checks);
 
        result = __bfs_forwards(root, (void *)bit, usage_match, target_entry);
 
@@ -1275,7 +1252,7 @@ find_usage_backwards(struct lock_list *root, enum lock_usage_bit bit,
 {
        int result;
 
-       debug_atomic_inc(&nr_find_usage_backwards_checks);
+       debug_atomic_inc(nr_find_usage_backwards_checks);
 
        result = __bfs_backwards(root, (void *)bit, usage_match, target_entry);
 
@@ -1835,7 +1812,7 @@ static inline int lookup_chain_cache(struct task_struct *curr,
        list_for_each_entry(chain, hash_head, entry) {
                if (chain->chain_key == chain_key) {
 cache_hit:
-                       debug_atomic_inc(&chain_lookup_hits);
+                       debug_atomic_inc(chain_lookup_hits);
                        if (very_verbose(class))
                                printk("\nhash chain already cached, key: "
                                        "%016Lx tail class: [%p] %s\n",
@@ -1900,7 +1877,7 @@ cache_hit:
                chain_hlocks[chain->base + j] = class - lock_classes;
        }
        list_add_tail_rcu(&chain->entry, hash_head);
-       debug_atomic_inc(&chain_lookup_misses);
+       debug_atomic_inc(chain_lookup_misses);
        inc_chains();
 
        return 1;
@@ -2147,7 +2124,7 @@ 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)
@@ -2321,7 +2298,12 @@ void trace_hardirqs_on_caller(unsigned long ip)
                return;
 
        if (unlikely(curr->hardirqs_enabled)) {
-               debug_atomic_inc(&redundant_hardirqs_on);
+               /*
+                * Neither irq nor preemption are disabled here
+                * so this is racy by nature but loosing one hit
+                * in a stat is not a big deal.
+                */
+               __debug_atomic_inc(redundant_hardirqs_on);
                return;
        }
        /* we'll do an OFF -> ON transition: */
@@ -2348,7 +2330,7 @@ void trace_hardirqs_on_caller(unsigned long ip)
 
        curr->hardirq_enable_ip = ip;
        curr->hardirq_enable_event = ++curr->irq_events;
-       debug_atomic_inc(&hardirqs_on_events);
+       debug_atomic_inc(hardirqs_on_events);
 }
 EXPORT_SYMBOL(trace_hardirqs_on_caller);
 
@@ -2380,9 +2362,9 @@ void trace_hardirqs_off_caller(unsigned long ip)
                curr->hardirqs_enabled = 0;
                curr->hardirq_disable_ip = ip;
                curr->hardirq_disable_event = ++curr->irq_events;
-               debug_atomic_inc(&hardirqs_off_events);
+               debug_atomic_inc(hardirqs_off_events);
        } else
-               debug_atomic_inc(&redundant_hardirqs_off);
+               debug_atomic_inc(redundant_hardirqs_off);
 }
 EXPORT_SYMBOL(trace_hardirqs_off_caller);
 
@@ -2406,7 +2388,7 @@ void trace_softirqs_on(unsigned long ip)
                return;
 
        if (curr->softirqs_enabled) {
-               debug_atomic_inc(&redundant_softirqs_on);
+               debug_atomic_inc(redundant_softirqs_on);
                return;
        }
 
@@ -2416,7 +2398,7 @@ void trace_softirqs_on(unsigned long ip)
        curr->softirqs_enabled = 1;
        curr->softirq_enable_ip = ip;
        curr->softirq_enable_event = ++curr->irq_events;
-       debug_atomic_inc(&softirqs_on_events);
+       debug_atomic_inc(softirqs_on_events);
        /*
         * We are going to turn softirqs on, so set the
         * usage bit for all held locks, if hardirqs are
@@ -2446,10 +2428,10 @@ void trace_softirqs_off(unsigned long ip)
                curr->softirqs_enabled = 0;
                curr->softirq_disable_ip = ip;
                curr->softirq_disable_event = ++curr->irq_events;
-               debug_atomic_inc(&softirqs_off_events);
+               debug_atomic_inc(softirqs_off_events);
                DEBUG_LOCKS_WARN_ON(!softirq_count());
        } else
-               debug_atomic_inc(&redundant_softirqs_off);
+               debug_atomic_inc(redundant_softirqs_off);
 }
 
 static void __lockdep_trace_alloc(gfp_t gfp_mask, unsigned long flags)
@@ -2654,7 +2636,7 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this,
                        return 0;
                break;
        case LOCK_USED:
-               debug_atomic_dec(&nr_unused_locks);
+               debug_atomic_dec(nr_unused_locks);
                break;
        default:
                if (!debug_locks_off_graph_unlock())
@@ -2760,7 +2742,7 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
                if (!class)
                        return 0;
        }
-       debug_atomic_inc((atomic_t *)&class->ops);
+       atomic_inc((atomic_t *)&class->ops);
        if (very_verbose(class)) {
                printk("\nacquire class [%p] %s", class->key, class->name);
                if (class->name_version > 1)
@@ -3211,8 +3193,6 @@ void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
 {
        unsigned long flags;
 
-       trace_lock_acquire(lock, subclass, trylock, read, check, nest_lock, ip);
-
        if (unlikely(current->lockdep_recursion))
                return;
 
@@ -3220,6 +3200,7 @@ void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
        check_flags(flags);
 
        current->lockdep_recursion = 1;
+       trace_lock_acquire(lock, subclass, trylock, read, check, nest_lock, ip);
        __lock_acquire(lock, subclass, trylock, read, check,
                       irqs_disabled_flags(flags), nest_lock, ip, 0);
        current->lockdep_recursion = 0;
@@ -3232,14 +3213,13 @@ void lock_release(struct lockdep_map *lock, int nested,
 {
        unsigned long flags;
 
-       trace_lock_release(lock, nested, ip);
-
        if (unlikely(current->lockdep_recursion))
                return;
 
        raw_local_irq_save(flags);
        check_flags(flags);
        current->lockdep_recursion = 1;
+       trace_lock_release(lock, nested, ip);
        __lock_release(lock, nested, ip);
        current->lockdep_recursion = 0;
        raw_local_irq_restore(flags);
@@ -3413,8 +3393,6 @@ void lock_contended(struct lockdep_map *lock, unsigned long ip)
 {
        unsigned long flags;
 
-       trace_lock_contended(lock, ip);
-
        if (unlikely(!lock_stat))
                return;
 
@@ -3424,6 +3402,7 @@ void lock_contended(struct lockdep_map *lock, unsigned long ip)
        raw_local_irq_save(flags);
        check_flags(flags);
        current->lockdep_recursion = 1;
+       trace_lock_contended(lock, ip);
        __lock_contended(lock, ip);
        current->lockdep_recursion = 0;
        raw_local_irq_restore(flags);
@@ -3809,3 +3788,22 @@ 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");
+       printk("\nrcu_scheduler_active = %d, debug_locks = %d\n", rcu_scheduler_active, debug_locks);
+       lockdep_print_held_locks(curr);
+       printk("\nstack backtrace:\n");
+       dump_stack();
+}
+EXPORT_SYMBOL_GPL(lockdep_rcu_dereference);