1 files changed, 69 insertions, 11 deletions

diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index 81a4e4a..d38a643 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -39,6 +39,7 @@
 #include <linux/irqflags.h>
 #include <linux/utsname.h>
 #include <linux/hash.h>
+#include <linux/ftrace.h>
 
 #include <asm/sections.h>
 
@@ -81,6 +82,8 @@ static int graph_lock(void)
 		__raw_spin_unlock(&lockdep_lock);
 		return 0;
 	}
+	/* prevent any recursions within lockdep from causing deadlocks */
+	current->lockdep_recursion++;
 	return 1;
 }
 
@@ -89,6 +92,7 @@ static inline int graph_unlock(void)
 	if (debug_locks && !__raw_spin_is_locked(&lockdep_lock))
 		return DEBUG_LOCKS_WARN_ON(1);
 
+	current->lockdep_recursion--;
 	__raw_spin_unlock(&lockdep_lock);
 	return 0;
 }
@@ -982,7 +986,7 @@ check_noncircular(struct lock_class *source, unsigned int depth)
 	return 1;
 }
 
-#ifdef CONFIG_TRACE_IRQFLAGS
+#if defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_PROVE_LOCKING)
 /*
  * Forwards and backwards subgraph searching, for the purposes of
  * proving that two subgraphs can be connected by a new dependency
@@ -1458,7 +1462,14 @@ out_bug:
 }
 
 unsigned long nr_lock_chains;
-static struct lock_chain lock_chains[MAX_LOCKDEP_CHAINS];
+struct lock_chain lock_chains[MAX_LOCKDEP_CHAINS];
+int nr_chain_hlocks;
+static u16 chain_hlocks[MAX_LOCKDEP_CHAIN_HLOCKS];
+
+struct lock_class *lock_chain_get_class(struct lock_chain *chain, int i)
+{
+	return lock_classes + chain_hlocks[chain->base + i];
+}
 
 /*
  * Look up a dependency chain. If the key is not present yet then
@@ -1466,10 +1477,15 @@ static struct lock_chain lock_chains[MAX_LOCKDEP_CHAINS];
  * validated. If the key is already hashed, return 0.
  * (On return with 1 graph_lock is held.)
  */
-static inline int lookup_chain_cache(u64 chain_key, struct lock_class *class)
+static inline int lookup_chain_cache(struct task_struct *curr,
+				     struct held_lock *hlock,
+				     u64 chain_key)
 {
+	struct lock_class *class = hlock->class;
 	struct list_head *hash_head = chainhashentry(chain_key);
 	struct lock_chain *chain;
+	struct held_lock *hlock_curr, *hlock_next;
+	int i, j, n, cn;
 
 	if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
 		return 0;
@@ -1517,6 +1533,32 @@ cache_hit:
 	}
 	chain = lock_chains + nr_lock_chains++;
 	chain->chain_key = chain_key;
+	chain->irq_context = hlock->irq_context;
+	/* Find the first held_lock of current chain */
+	hlock_next = hlock;
+	for (i = curr->lockdep_depth - 1; i >= 0; i--) {
+		hlock_curr = curr->held_locks + i;
+		if (hlock_curr->irq_context != hlock_next->irq_context)
+			break;
+		hlock_next = hlock;
+	}
+	i++;
+	chain->depth = curr->lockdep_depth + 1 - i;
+	cn = nr_chain_hlocks;
+	while (cn + chain->depth <= MAX_LOCKDEP_CHAIN_HLOCKS) {
+		n = cmpxchg(&nr_chain_hlocks, cn, cn + chain->depth);
+		if (n == cn)
+			break;
+		cn = n;
+	}
+	if (likely(cn + chain->depth <= MAX_LOCKDEP_CHAIN_HLOCKS)) {
+		chain->base = cn;
+		for (j = 0; j < chain->depth - 1; j++, i++) {
+			int lock_id = curr->held_locks[i].class - lock_classes;
+			chain_hlocks[chain->base + j] = lock_id;
+		}
+		chain_hlocks[chain->base + j] = class - lock_classes;
+	}
 	list_add_tail_rcu(&chain->entry, hash_head);
 	debug_atomic_inc(&chain_lookup_misses);
 	inc_chains();
@@ -1538,7 +1580,7 @@ static int validate_chain(struct task_struct *curr, struct lockdep_map *lock,
 	 * graph_lock for us)
 	 */
 	if (!hlock->trylock && (hlock->check == 2) &&
-			lookup_chain_cache(chain_key, hlock->class)) {
+	    lookup_chain_cache(curr, hlock, chain_key)) {
 		/*
 		 * Check whether last held lock:
 		 *
@@ -1680,7 +1722,7 @@ valid_state(struct task_struct *curr, struct held_lock *this,
 static int mark_lock(struct task_struct *curr, struct held_lock *this,
 		     enum lock_usage_bit new_bit);
 
-#ifdef CONFIG_TRACE_IRQFLAGS
+#if defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_PROVE_LOCKING)
 
 /*
  * print irq inversion bug:
@@ -2013,11 +2055,13 @@ void early_boot_irqs_on(void)
 /*
  * Hardirqs will be enabled:
  */
-void trace_hardirqs_on(void)
+void trace_hardirqs_on_caller(unsigned long a0)
 {
 	struct task_struct *curr = current;
 	unsigned long ip;
 
+	time_hardirqs_on(CALLER_ADDR0, a0);
+
 	if (unlikely(!debug_locks || current->lockdep_recursion))
 		return;
 
@@ -2055,16 +2099,23 @@ void trace_hardirqs_on(void)
 	curr->hardirq_enable_event = ++curr->irq_events;
 	debug_atomic_inc(&hardirqs_on_events);
 }
+EXPORT_SYMBOL(trace_hardirqs_on_caller);
 
+void trace_hardirqs_on(void)
+{
+	trace_hardirqs_on_caller(CALLER_ADDR0);
+}
 EXPORT_SYMBOL(trace_hardirqs_on);
 
 /*
  * Hardirqs were disabled:
  */
-void trace_hardirqs_off(void)
+void trace_hardirqs_off_caller(unsigned long a0)
 {
 	struct task_struct *curr = current;
 
+	time_hardirqs_off(CALLER_ADDR0, a0);
+
 	if (unlikely(!debug_locks || current->lockdep_recursion))
 		return;
 
@@ -2082,7 +2133,12 @@ void trace_hardirqs_off(void)
 	} else
 		debug_atomic_inc(&redundant_hardirqs_off);
 }
+EXPORT_SYMBOL(trace_hardirqs_off_caller);
 
+void trace_hardirqs_off(void)
+{
+	trace_hardirqs_off_caller(CALLER_ADDR0);
+}
 EXPORT_SYMBOL(trace_hardirqs_off);
 
 /*
@@ -2246,7 +2302,7 @@ static inline int separate_irq_context(struct task_struct *curr,
  * Mark a lock with a usage bit, and validate the state transition:
  */
 static int mark_lock(struct task_struct *curr, struct held_lock *this,
-		     enum lock_usage_bit new_bit)
+			     enum lock_usage_bit new_bit)
 {
 	unsigned int new_mask = 1 << new_bit, ret = 1;
 
@@ -2650,7 +2706,8 @@ __lock_release(struct lockdep_map *lock, int nested, unsigned long ip)
  */
 static void check_flags(unsigned long flags)
 {
-#if defined(CONFIG_DEBUG_LOCKDEP) && defined(CONFIG_TRACE_IRQFLAGS)
+#if defined(CONFIG_PROVE_LOCKING) && defined(CONFIG_DEBUG_LOCKDEP) && \
+    defined(CONFIG_TRACE_IRQFLAGS)
 	if (!debug_locks)
 		return;
 
@@ -2686,7 +2743,7 @@ static void check_flags(unsigned long flags)
  * and also avoid lockdep recursion:
  */
 void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
-		  int trylock, int read, int check, unsigned long ip)
+			  int trylock, int read, int check, unsigned long ip)
 {
 	unsigned long flags;
 
@@ -2708,7 +2765,8 @@ void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
 
 EXPORT_SYMBOL_GPL(lock_acquire);
 
-void lock_release(struct lockdep_map *lock, int nested, unsigned long ip)
+void lock_release(struct lockdep_map *lock, int nested,
+			  unsigned long ip)
 {
 	unsigned long flags;