* Thanks to Arjan van de Ven for coming up with the initial idea of
* mapping lock dependencies runtime.
*/
+#define DISABLE_BRANCH_PROFILING
#include <linux/mutex.h>
#include <linux/sched.h>
#include <linux/delay.h>
#include <linux/irqflags.h>
#include <linux/utsname.h>
#include <linux/hash.h>
+#include <linux/ftrace.h>
#include <asm/sections.h>
__raw_spin_unlock(&lockdep_lock);
return 0;
}
+ /* prevent any recursions within lockdep from causing deadlocks */
+ current->lockdep_recursion++;
return 1;
}
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;
}
unsigned long nr_lock_classes;
static struct lock_class lock_classes[MAX_LOCKDEP_KEYS];
+static inline struct lock_class *hlock_class(struct held_lock *hlock)
+{
+ if (!hlock->class_idx) {
+ DEBUG_LOCKS_WARN_ON(1);
+ return NULL;
+ }
+ return lock_classes + hlock->class_idx - 1;
+}
+
#ifdef CONFIG_LOCK_STAT
static DEFINE_PER_CPU(struct lock_class_stats[MAX_LOCKDEP_KEYS], lock_stats);
-static int lock_contention_point(struct lock_class *class, unsigned long ip)
+static int lock_point(unsigned long points[], unsigned long ip)
{
int i;
- for (i = 0; i < ARRAY_SIZE(class->contention_point); i++) {
- if (class->contention_point[i] == 0) {
- class->contention_point[i] = ip;
+ for (i = 0; i < LOCKSTAT_POINTS; i++) {
+ if (points[i] == 0) {
+ points[i] = ip;
break;
}
- if (class->contention_point[i] == ip)
+ if (points[i] == ip)
break;
}
for (i = 0; i < ARRAY_SIZE(stats.contention_point); i++)
stats.contention_point[i] += pcs->contention_point[i];
+ for (i = 0; i < ARRAY_SIZE(stats.contending_point); i++)
+ stats.contending_point[i] += pcs->contending_point[i];
+
lock_time_add(&pcs->read_waittime, &stats.read_waittime);
lock_time_add(&pcs->write_waittime, &stats.write_waittime);
memset(cpu_stats, 0, sizeof(struct lock_class_stats));
}
memset(class->contention_point, 0, sizeof(class->contention_point));
+ memset(class->contending_point, 0, sizeof(class->contending_point));
}
static struct lock_class_stats *get_lock_stats(struct lock_class *class)
holdtime = sched_clock() - hlock->holdtime_stamp;
- stats = get_lock_stats(hlock->class);
+ stats = get_lock_stats(hlock_class(hlock));
if (hlock->read)
lock_time_inc(&stats->read_holdtime, holdtime);
else
{
current->lockdep_recursion++;
}
-
EXPORT_SYMBOL(lockdep_off);
void lockdep_on(void)
{
current->lockdep_recursion--;
}
-
EXPORT_SYMBOL(lockdep_on);
/*
unsigned int max_lockdep_depth;
unsigned int max_recursion_depth;
+static unsigned int lockdep_dependency_gen_id;
+
+static bool lockdep_dependency_visit(struct lock_class *source,
+ unsigned int depth)
+{
+ if (!depth)
+ lockdep_dependency_gen_id++;
+ if (source->dep_gen_id == lockdep_dependency_gen_id)
+ return true;
+ source->dep_gen_id = lockdep_dependency_gen_id;
+ return false;
+}
+
#ifdef CONFIG_DEBUG_LOCKDEP
/*
* We cannot printk in early bootup code. Not even early_printk()
static void print_lock(struct held_lock *hlock)
{
- print_lock_name(hlock->class);
+ print_lock_name(hlock_class(hlock));
printk(", at: ");
print_ip_sym(hlock->acquire_ip);
}
int i, depth = curr->lockdep_depth;
if (!depth) {
- printk("no locks held by %s/%d.\n", curr->comm, curr->pid);
+ printk("no locks held by %s/%d.\n", curr->comm, task_pid_nr(curr));
return;
}
printk("%d lock%s held by %s/%d:\n",
- depth, depth > 1 ? "s" : "", curr->comm, curr->pid);
+ depth, depth > 1 ? "s" : "", curr->comm, task_pid_nr(curr));
for (i = 0; i < depth; i++) {
printk(" #%d: ", i);
/*
* printk all lock dependencies starting at <entry>:
*/
-static void print_lock_dependencies(struct lock_class *class, int depth)
+static void __used
+print_lock_dependencies(struct lock_class *class, int depth)
{
struct lock_list *entry;
+ if (lockdep_dependency_visit(class, depth))
+ return;
+
if (DEBUG_LOCKS_WARN_ON(depth >= 20))
return;
* parallel walking of the hash-list safe:
*/
list_add_tail_rcu(&class->hash_entry, hash_head);
+ /*
+ * Add it to the global list of classes:
+ */
+ list_add_tail_rcu(&class->lock_entry, &all_lock_classes);
if (verbose(class)) {
graph_unlock();
if (!entry)
return 0;
- entry->class = this;
- entry->distance = distance;
if (!save_trace(&entry->trace))
return 0;
+ entry->class = this;
+ entry->distance = distance;
/*
* Since we never remove from the dependency list, the list can
* be walked lockless by other CPUs, it's only allocation
print_kernel_version();
printk( "-------------------------------------------------------\n");
printk("%s/%d is trying to acquire lock:\n",
- curr->comm, curr->pid);
+ curr->comm, task_pid_nr(curr));
print_lock(check_source);
printk("\nbut task is already holding lock:\n");
print_lock(check_target);
if (debug_locks_silent)
return 0;
- this.class = check_source->class;
+ this.class = hlock_class(check_source);
if (!save_trace(&this.trace))
return 0;
return 0;
}
+unsigned long __lockdep_count_forward_deps(struct lock_class *class,
+ unsigned int depth)
+{
+ struct lock_list *entry;
+ unsigned long ret = 1;
+
+ if (lockdep_dependency_visit(class, depth))
+ return 0;
+
+ /*
+ * Recurse this class's dependency list:
+ */
+ list_for_each_entry(entry, &class->locks_after, entry)
+ ret += __lockdep_count_forward_deps(entry->class, depth + 1);
+
+ return ret;
+}
+
+unsigned long lockdep_count_forward_deps(struct lock_class *class)
+{
+ unsigned long ret, flags;
+
+ local_irq_save(flags);
+ __raw_spin_lock(&lockdep_lock);
+ ret = __lockdep_count_forward_deps(class, 0);
+ __raw_spin_unlock(&lockdep_lock);
+ local_irq_restore(flags);
+
+ return ret;
+}
+
+unsigned long __lockdep_count_backward_deps(struct lock_class *class,
+ unsigned int depth)
+{
+ struct lock_list *entry;
+ unsigned long ret = 1;
+
+ if (lockdep_dependency_visit(class, depth))
+ return 0;
+ /*
+ * Recurse this class's dependency list:
+ */
+ list_for_each_entry(entry, &class->locks_before, entry)
+ ret += __lockdep_count_backward_deps(entry->class, depth + 1);
+
+ return ret;
+}
+
+unsigned long lockdep_count_backward_deps(struct lock_class *class)
+{
+ unsigned long ret, flags;
+
+ local_irq_save(flags);
+ __raw_spin_lock(&lockdep_lock);
+ ret = __lockdep_count_backward_deps(class, 0);
+ __raw_spin_unlock(&lockdep_lock);
+ local_irq_restore(flags);
+
+ return ret;
+}
+
/*
* Prove that the dependency graph starting at <entry> can not
* lead to <target>. Print an error and return 0 if it does.
{
struct lock_list *entry;
+ if (lockdep_dependency_visit(source, depth))
+ return 1;
+
debug_atomic_inc(&nr_cyclic_check_recursions);
if (depth > max_recursion_depth)
max_recursion_depth = depth;
* Check this lock's dependency list:
*/
list_for_each_entry(entry, &source->locks_after, entry) {
- if (entry->class == check_target->class)
+ if (entry->class == hlock_class(check_target))
return print_circular_bug_header(entry, depth+1);
debug_atomic_inc(&nr_cyclic_checks);
if (!check_noncircular(entry->class, depth+1))
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
struct lock_list *entry;
int ret;
+ if (lockdep_dependency_visit(source, depth))
+ return 1;
+
if (depth > max_recursion_depth)
max_recursion_depth = depth;
if (depth >= RECURSION_LIMIT)
struct lock_list *entry;
int ret;
+ if (lockdep_dependency_visit(source, depth))
+ return 1;
+
if (!__raw_spin_is_locked(&lockdep_lock))
return DEBUG_LOCKS_WARN_ON(1);
return 2;
}
+ if (!source && debug_locks_off_graph_unlock()) {
+ WARN_ON(1);
+ return 0;
+ }
+
/*
* Check this lock's dependency list:
*/
print_kernel_version();
printk( "------------------------------------------------------\n");
printk("%s/%d [HC%u[%lu]:SC%u[%lu]:HE%u:SE%u] is trying to acquire:\n",
- curr->comm, curr->pid,
+ curr->comm, task_pid_nr(curr),
curr->hardirq_context, hardirq_count() >> HARDIRQ_SHIFT,
curr->softirq_context, softirq_count() >> SOFTIRQ_SHIFT,
curr->hardirqs_enabled,
printk("\nand this task is already holding:\n");
print_lock(prev);
printk("which would create a new lock dependency:\n");
- print_lock_name(prev->class);
+ print_lock_name(hlock_class(prev));
printk(" ->");
- print_lock_name(next->class);
+ print_lock_name(hlock_class(next));
printk("\n");
printk("\nbut this new dependency connects a %s-irq-safe lock:\n",
find_usage_bit = bit_backwards;
/* fills in <backwards_match> */
- ret = find_usage_backwards(prev->class, 0);
+ ret = find_usage_backwards(hlock_class(prev), 0);
if (!ret || ret == 1)
return ret;
find_usage_bit = bit_forwards;
- ret = find_usage_forwards(next->class, 0);
+ ret = find_usage_forwards(hlock_class(next), 0);
if (!ret || ret == 1)
return ret;
/* ret == 2 */
print_kernel_version();
printk( "---------------------------------------------\n");
printk("%s/%d is trying to acquire lock:\n",
- curr->comm, curr->pid);
+ curr->comm, task_pid_nr(curr));
print_lock(next);
printk("\nbut task is already holding lock:\n");
print_lock(prev);
struct lockdep_map *next_instance, int read)
{
struct held_lock *prev;
+ struct held_lock *nest = NULL;
int i;
for (i = 0; i < curr->lockdep_depth; i++) {
prev = curr->held_locks + i;
- if (prev->class != next->class)
+
+ if (prev->instance == next->nest_lock)
+ nest = prev;
+
+ if (hlock_class(prev) != hlock_class(next))
continue;
+
/*
* Allow read-after-read recursion of the same
* lock class (i.e. read_lock(lock)+read_lock(lock)):
*/
if ((read == 2) && prev->read)
return 2;
+
+ /*
+ * We're holding the nest_lock, which serializes this lock's
+ * nesting behaviour.
+ */
+ if (nest)
+ return 2;
+
return print_deadlock_bug(curr, prev, next);
}
return 1;
*/
check_source = next;
check_target = prev;
- if (!(check_noncircular(next->class, 0)))
+ if (!(check_noncircular(hlock_class(next), 0)))
return print_circular_bug_tail();
if (!check_prev_add_irq(curr, prev, next))
* chains - the second one will be new, but L1 already has
* L2 added to its dependency list, due to the first chain.)
*/
- list_for_each_entry(entry, &prev->class->locks_after, entry) {
- if (entry->class == next->class) {
+ list_for_each_entry(entry, &hlock_class(prev)->locks_after, entry) {
+ if (entry->class == hlock_class(next)) {
if (distance == 1)
entry->distance = 1;
return 2;
* Ok, all validations passed, add the new lock
* to the previous lock's dependency list:
*/
- ret = add_lock_to_list(prev->class, next->class,
- &prev->class->locks_after, next->acquire_ip, distance);
+ ret = add_lock_to_list(hlock_class(prev), hlock_class(next),
+ &hlock_class(prev)->locks_after,
+ next->acquire_ip, distance);
if (!ret)
return 0;
- ret = add_lock_to_list(next->class, prev->class,
- &next->class->locks_before, next->acquire_ip, distance);
+ ret = add_lock_to_list(hlock_class(next), hlock_class(prev),
+ &hlock_class(next)->locks_before,
+ next->acquire_ip, distance);
if (!ret)
return 0;
/*
* Debugging printouts:
*/
- if (verbose(prev->class) || verbose(next->class)) {
+ if (verbose(hlock_class(prev)) || verbose(hlock_class(next))) {
graph_unlock();
printk("\n new dependency: ");
- print_lock_name(prev->class);
+ print_lock_name(hlock_class(prev));
printk(" => ");
- print_lock_name(next->class);
+ print_lock_name(hlock_class(next));
printk("\n");
dump_stack();
return graph_lock();
}
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
* 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(hlock);
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;
}
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_idx - 1;
+ 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();
}
static int validate_chain(struct task_struct *curr, struct lockdep_map *lock,
- struct held_lock *hlock, int chain_head, u64 chain_key)
+ struct held_lock *hlock, int chain_head, u64 chain_key)
{
/*
* Trylock needs to maintain the stack of held locks, but it
* 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:
*
hlock = curr->held_locks + i;
if (chain_key != hlock->prev_chain_key) {
debug_locks_off();
- printk("hm#1, depth: %u [%u], %016Lx != %016Lx\n",
+ WARN(1, "hm#1, depth: %u [%u], %016Lx != %016Lx\n",
curr->lockdep_depth, i,
(unsigned long long)chain_key,
(unsigned long long)hlock->prev_chain_key);
- WARN_ON(1);
return;
}
- id = hlock->class - lock_classes;
+ id = hlock->class_idx - 1;
if (DEBUG_LOCKS_WARN_ON(id >= MAX_LOCKDEP_KEYS))
return;
}
if (chain_key != curr->curr_chain_key) {
debug_locks_off();
- printk("hm#2, depth: %u [%u], %016Lx != %016Lx\n",
+ WARN(1, "hm#2, depth: %u [%u], %016Lx != %016Lx\n",
curr->lockdep_depth, i,
(unsigned long long)chain_key,
(unsigned long long)curr->curr_chain_key);
- WARN_ON(1);
}
#endif
}
usage_str[prev_bit], usage_str[new_bit]);
printk("%s/%d [HC%u[%lu]:SC%u[%lu]:HE%u:SE%u] takes:\n",
- curr->comm, curr->pid,
+ curr->comm, task_pid_nr(curr),
trace_hardirq_context(curr), hardirq_count() >> HARDIRQ_SHIFT,
trace_softirq_context(curr), softirq_count() >> SOFTIRQ_SHIFT,
trace_hardirqs_enabled(curr),
print_lock(this);
printk("{%s} state was registered at:\n", usage_str[prev_bit]);
- print_stack_trace(this->class->usage_traces + prev_bit, 1);
+ print_stack_trace(hlock_class(this)->usage_traces + prev_bit, 1);
print_irqtrace_events(curr);
printk("\nother info that might help us debug this:\n");
valid_state(struct task_struct *curr, struct held_lock *this,
enum lock_usage_bit new_bit, enum lock_usage_bit bad_bit)
{
- if (unlikely(this->class->usage_mask & (1 << bad_bit)))
+ if (unlikely(hlock_class(this)->usage_mask & (1 << bad_bit)))
return print_usage_bug(curr, this, bad_bit, new_bit);
return 1;
}
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:
print_kernel_version();
printk( "---------------------------------------------------------\n");
printk("%s/%d just changed the state of lock:\n",
- curr->comm, curr->pid);
+ curr->comm, task_pid_nr(curr));
print_lock(this);
if (forwards)
printk("but this lock took another, %s-irq-unsafe lock in the past:\n", irqclass);
lockdep_print_held_locks(curr);
printk("\nthe first lock's dependencies:\n");
- print_lock_dependencies(this->class, 0);
+ print_lock_dependencies(hlock_class(this), 0);
printk("\nthe second lock's dependencies:\n");
print_lock_dependencies(other, 0);
find_usage_bit = bit;
/* fills in <forwards_match> */
- ret = find_usage_forwards(this->class, 0);
+ ret = find_usage_forwards(hlock_class(this), 0);
if (!ret || ret == 1)
return ret;
find_usage_bit = bit;
/* fills in <backwards_match> */
- ret = find_usage_backwards(this->class, 0);
+ ret = find_usage_backwards(hlock_class(this), 0);
if (!ret || ret == 1)
return ret;
LOCK_ENABLED_HARDIRQS_READ, "hard-read"))
return 0;
#endif
- if (hardirq_verbose(this->class))
+ if (hardirq_verbose(hlock_class(this)))
ret = 2;
break;
case LOCK_USED_IN_SOFTIRQ:
LOCK_ENABLED_SOFTIRQS_READ, "soft-read"))
return 0;
#endif
- if (softirq_verbose(this->class))
+ if (softirq_verbose(hlock_class(this)))
ret = 2;
break;
case LOCK_USED_IN_HARDIRQ_READ:
if (!check_usage_forwards(curr, this,
LOCK_ENABLED_HARDIRQS, "hard"))
return 0;
- if (hardirq_verbose(this->class))
+ if (hardirq_verbose(hlock_class(this)))
ret = 2;
break;
case LOCK_USED_IN_SOFTIRQ_READ:
if (!check_usage_forwards(curr, this,
LOCK_ENABLED_SOFTIRQS, "soft"))
return 0;
- if (softirq_verbose(this->class))
+ if (softirq_verbose(hlock_class(this)))
ret = 2;
break;
case LOCK_ENABLED_HARDIRQS:
LOCK_USED_IN_HARDIRQ_READ, "hard-read"))
return 0;
#endif
- if (hardirq_verbose(this->class))
+ if (hardirq_verbose(hlock_class(this)))
ret = 2;
break;
case LOCK_ENABLED_SOFTIRQS:
LOCK_USED_IN_SOFTIRQ_READ, "soft-read"))
return 0;
#endif
- if (softirq_verbose(this->class))
+ if (softirq_verbose(hlock_class(this)))
ret = 2;
break;
case LOCK_ENABLED_HARDIRQS_READ:
LOCK_USED_IN_HARDIRQ, "hard"))
return 0;
#endif
- if (hardirq_verbose(this->class))
+ if (hardirq_verbose(hlock_class(this)))
ret = 2;
break;
case LOCK_ENABLED_SOFTIRQS_READ:
LOCK_USED_IN_SOFTIRQ, "soft"))
return 0;
#endif
- if (softirq_verbose(this->class))
+ if (softirq_verbose(hlock_class(this)))
ret = 2;
break;
default:
/*
* Hardirqs will be enabled:
*/
-void trace_hardirqs_on(void)
+void trace_hardirqs_on_caller(unsigned long ip)
{
struct task_struct *curr = current;
- unsigned long ip;
+
+ time_hardirqs_on(CALLER_ADDR0, ip);
if (unlikely(!debug_locks || current->lockdep_recursion))
return;
}
/* we'll do an OFF -> ON transition: */
curr->hardirqs_enabled = 1;
- ip = (unsigned long) __builtin_return_address(0);
if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
return;
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 ip)
{
struct task_struct *curr = current;
+ time_hardirqs_off(CALLER_ADDR0, ip);
+
if (unlikely(!debug_locks || current->lockdep_recursion))
return;
* We have done an ON -> OFF transition:
*/
curr->hardirqs_enabled = 0;
- curr->hardirq_disable_ip = _RET_IP_;
+ curr->hardirq_disable_ip = ip;
curr->hardirq_disable_event = ++curr->irq_events;
debug_atomic_inc(&hardirqs_off_events);
} 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);
/*
* 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;
* If already set then do not dirty the cacheline,
* nor do any checks:
*/
- if (likely(this->class->usage_mask & new_mask))
+ if (likely(hlock_class(this)->usage_mask & new_mask))
return 1;
if (!graph_lock())
/*
* Make sure we didnt race:
*/
- if (unlikely(this->class->usage_mask & new_mask)) {
+ if (unlikely(hlock_class(this)->usage_mask & new_mask)) {
graph_unlock();
return 1;
}
- this->class->usage_mask |= new_mask;
+ hlock_class(this)->usage_mask |= new_mask;
- if (!save_trace(this->class->usage_traces + new_bit))
+ if (!save_trace(hlock_class(this)->usage_traces + new_bit))
return 0;
switch (new_bit) {
return 0;
break;
case LOCK_USED:
- /*
- * Add it to the global list of classes:
- */
- list_add_tail_rcu(&this->class->lock_entry, &all_lock_classes);
debug_atomic_dec(&nr_unused_locks);
break;
default:
if (subclass)
register_lock_class(lock, subclass, 1);
}
-
EXPORT_SYMBOL_GPL(lockdep_init_map);
/*
*/
static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
int trylock, int read, int check, int hardirqs_off,
- unsigned long ip)
+ struct lockdep_map *nest_lock, unsigned long ip)
{
struct task_struct *curr = current;
struct lock_class *class = NULL;
return 0;
hlock = curr->held_locks + depth;
-
- hlock->class = class;
+ if (DEBUG_LOCKS_WARN_ON(!class))
+ return 0;
+ hlock->class_idx = class - lock_classes + 1;
hlock->acquire_ip = ip;
hlock->instance = lock;
+ hlock->nest_lock = nest_lock;
hlock->trylock = trylock;
hlock->read = read;
hlock->check = check;
- hlock->hardirqs_off = hardirqs_off;
+ hlock->hardirqs_off = !!hardirqs_off;
#ifdef CONFIG_LOCK_STAT
hlock->waittime_stamp = 0;
hlock->holdtime_stamp = sched_clock();
return 0;
/*
- * Calculate the chain hash: it's the combined has of all the
+ * Calculate the chain hash: it's the combined hash of all the
* lock keys along the dependency chain. We save the hash value
* at every step so that we can get the current hash easily
* after unlock. The chain hash is then used to cache dependency
printk( "[ BUG: bad unlock balance detected! ]\n");
printk( "-------------------------------------\n");
printk("%s/%d is trying to release lock (",
- curr->comm, curr->pid);
+ curr->comm, task_pid_nr(curr));
print_lockdep_cache(lock);
printk(") at:\n");
print_ip_sym(ip);
return 1;
}
+static int
+__lock_set_class(struct lockdep_map *lock, const char *name,
+ struct lock_class_key *key, unsigned int subclass,
+ unsigned long ip)
+{
+ struct task_struct *curr = current;
+ struct held_lock *hlock, *prev_hlock;
+ struct lock_class *class;
+ unsigned int depth;
+ int i;
+
+ depth = curr->lockdep_depth;
+ if (DEBUG_LOCKS_WARN_ON(!depth))
+ return 0;
+
+ prev_hlock = NULL;
+ for (i = depth-1; i >= 0; i--) {
+ hlock = curr->held_locks + i;
+ /*
+ * We must not cross into another context:
+ */
+ if (prev_hlock && prev_hlock->irq_context != hlock->irq_context)
+ break;
+ if (hlock->instance == lock)
+ goto found_it;
+ prev_hlock = hlock;
+ }
+ return print_unlock_inbalance_bug(curr, lock, ip);
+
+found_it:
+ lockdep_init_map(lock, name, key, 0);
+ class = register_lock_class(lock, subclass, 0);
+ hlock->class_idx = class - lock_classes + 1;
+
+ curr->lockdep_depth = i;
+ curr->curr_chain_key = hlock->prev_chain_key;
+
+ for (; i < depth; i++) {
+ hlock = curr->held_locks + i;
+ if (!__lock_acquire(hlock->instance,
+ hlock_class(hlock)->subclass, hlock->trylock,
+ hlock->read, hlock->check, hlock->hardirqs_off,
+ hlock->nest_lock, hlock->acquire_ip))
+ return 0;
+ }
+
+ if (DEBUG_LOCKS_WARN_ON(curr->lockdep_depth != depth))
+ return 0;
+ return 1;
+}
+
/*
* Remove the lock to the list of currently held locks in a
* potentially non-nested (out of order) manner. This is a
for (i++; i < depth; i++) {
hlock = curr->held_locks + i;
if (!__lock_acquire(hlock->instance,
- hlock->class->subclass, hlock->trylock,
+ hlock_class(hlock)->subclass, hlock->trylock,
hlock->read, hlock->check, hlock->hardirqs_off,
- hlock->acquire_ip))
+ hlock->nest_lock, hlock->acquire_ip))
return 0;
}
#ifdef CONFIG_DEBUG_LOCKDEP
hlock->prev_chain_key = 0;
- hlock->class = NULL;
+ hlock->class_idx = 0;
hlock->acquire_ip = 0;
hlock->irq_context = 0;
#endif
*/
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;
- if (irqs_disabled_flags(flags))
- DEBUG_LOCKS_WARN_ON(current->hardirqs_enabled);
- else
- DEBUG_LOCKS_WARN_ON(!current->hardirqs_enabled);
+ if (irqs_disabled_flags(flags)) {
+ if (DEBUG_LOCKS_WARN_ON(current->hardirqs_enabled)) {
+ printk("possible reason: unannotated irqs-off.\n");
+ }
+ } else {
+ if (DEBUG_LOCKS_WARN_ON(!current->hardirqs_enabled)) {
+ printk("possible reason: unannotated irqs-on.\n");
+ }
+ }
/*
* We dont accurately track softirq state in e.g.
#endif
}
+void lock_set_class(struct lockdep_map *lock, const char *name,
+ struct lock_class_key *key, unsigned int subclass,
+ unsigned long ip)
+{
+ unsigned long flags;
+
+ if (unlikely(current->lockdep_recursion))
+ return;
+
+ raw_local_irq_save(flags);
+ current->lockdep_recursion = 1;
+ check_flags(flags);
+ if (__lock_set_class(lock, name, key, subclass, ip))
+ check_chain_key(current);
+ current->lockdep_recursion = 0;
+ raw_local_irq_restore(flags);
+}
+EXPORT_SYMBOL_GPL(lock_set_class);
+
/*
* We are not always called with irqs disabled - do that here,
* 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,
+ struct lockdep_map *nest_lock, unsigned long ip)
{
unsigned long flags;
- if (unlikely(!lock_stat && !prove_locking))
- return;
-
if (unlikely(current->lockdep_recursion))
return;
current->lockdep_recursion = 1;
__lock_acquire(lock, subclass, trylock, read, check,
- irqs_disabled_flags(flags), ip);
+ irqs_disabled_flags(flags), nest_lock, ip);
current->lockdep_recursion = 0;
raw_local_irq_restore(flags);
}
-
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;
- if (unlikely(!lock_stat && !prove_locking))
- return;
-
if (unlikely(current->lockdep_recursion))
return;
current->lockdep_recursion = 0;
raw_local_irq_restore(flags);
}
-
EXPORT_SYMBOL_GPL(lock_release);
#ifdef CONFIG_LOCK_STAT
printk( "[ BUG: bad contention detected! ]\n");
printk( "---------------------------------\n");
printk("%s/%d is trying to contend lock (",
- curr->comm, curr->pid);
+ curr->comm, task_pid_nr(curr));
print_lockdep_cache(lock);
printk(") at:\n");
print_ip_sym(ip);
struct held_lock *hlock, *prev_hlock;
struct lock_class_stats *stats;
unsigned int depth;
- int i, point;
+ int i, contention_point, contending_point;
depth = curr->lockdep_depth;
if (DEBUG_LOCKS_WARN_ON(!depth))
found_it:
hlock->waittime_stamp = sched_clock();
- point = lock_contention_point(hlock->class, ip);
+ contention_point = lock_point(hlock_class(hlock)->contention_point, ip);
+ contending_point = lock_point(hlock_class(hlock)->contending_point,
+ lock->ip);
- stats = get_lock_stats(hlock->class);
- if (point < ARRAY_SIZE(stats->contention_point))
- stats->contention_point[i]++;
+ stats = get_lock_stats(hlock_class(hlock));
+ if (contention_point < LOCKSTAT_POINTS)
+ stats->contention_point[contention_point]++;
+ if (contending_point < LOCKSTAT_POINTS)
+ stats->contending_point[contending_point]++;
if (lock->cpu != smp_processor_id())
stats->bounces[bounce_contended + !!hlock->read]++;
put_lock_stats(stats);
}
static void
-__lock_acquired(struct lockdep_map *lock)
+__lock_acquired(struct lockdep_map *lock, unsigned long ip)
{
struct task_struct *curr = current;
struct held_lock *hlock, *prev_hlock;
hlock->holdtime_stamp = now;
}
- stats = get_lock_stats(hlock->class);
+ stats = get_lock_stats(hlock_class(hlock));
if (waittime) {
if (hlock->read)
lock_time_inc(&stats->read_waittime, waittime);
put_lock_stats(stats);
lock->cpu = cpu;
+ lock->ip = ip;
}
void lock_contended(struct lockdep_map *lock, unsigned long ip)
}
EXPORT_SYMBOL_GPL(lock_contended);
-void lock_acquired(struct lockdep_map *lock)
+void lock_acquired(struct lockdep_map *lock, unsigned long ip)
{
unsigned long flags;
raw_local_irq_save(flags);
check_flags(flags);
current->lockdep_recursion = 1;
- __lock_acquired(lock);
+ __lock_acquired(lock, ip);
current->lockdep_recursion = 0;
raw_local_irq_restore(flags);
}
list_del_rcu(&class->hash_entry);
list_del_rcu(&class->lock_entry);
+ class->key = NULL;
}
-static inline int within(void *addr, void *start, unsigned long size)
+static inline int within(const void *addr, void *start, unsigned long size)
{
return addr >= start && addr < start + size;
}
struct list_head *head;
unsigned long flags;
int i;
+ int locked;
raw_local_irq_save(flags);
- graph_lock();
+ locked = graph_lock();
/*
* Unhash all classes that were created by this module:
head = classhash_table + i;
if (list_empty(head))
continue;
- list_for_each_entry_safe(class, next, head, hash_entry)
+ list_for_each_entry_safe(class, next, head, hash_entry) {
if (within(class->key, start, size))
zap_class(class);
+ else if (within(class->name, start, size))
+ zap_class(class);
+ }
}
- graph_unlock();
+ if (locked)
+ graph_unlock();
raw_local_irq_restore(flags);
}
struct list_head *head;
unsigned long flags;
int i, j;
+ int locked;
raw_local_irq_save(flags);
* Debug check: in the end all mapped classes should
* be gone.
*/
- graph_lock();
+ locked = graph_lock();
for (i = 0; i < CLASSHASH_SIZE; i++) {
head = classhash_table + i;
if (list_empty(head))
}
}
}
- graph_unlock();
+ if (locked)
+ graph_unlock();
out_restore:
raw_local_irq_restore(flags);
{
printk("Lock dependency validator: Copyright (c) 2006 Red Hat, Inc., Ingo Molnar\n");
- printk("... MAX_LOCKDEP_SUBCLASSES: %lu\n", MAX_LOCKDEP_SUBCLASSES);
+ printk("... MAX_LOCKDEP_SUBCLASSES: %lu\n", MAX_LOCKDEP_SUBCLASSES);
printk("... MAX_LOCK_DEPTH: %lu\n", MAX_LOCK_DEPTH);
printk("... MAX_LOCKDEP_KEYS: %lu\n", MAX_LOCKDEP_KEYS);
- printk("... CLASSHASH_SIZE: %lu\n", CLASSHASH_SIZE);
+ printk("... CLASSHASH_SIZE: %lu\n", CLASSHASH_SIZE);
printk("... MAX_LOCKDEP_ENTRIES: %lu\n", MAX_LOCKDEP_ENTRIES);
printk("... MAX_LOCKDEP_CHAINS: %lu\n", MAX_LOCKDEP_CHAINS);
printk("... CHAINHASH_SIZE: %lu\n", CHAINHASH_SIZE);
#endif
}
-static inline int in_range(const void *start, const void *addr, const void *end)
-{
- return addr >= start && addr <= end;
-}
-
static void
print_freed_lock_bug(struct task_struct *curr, const void *mem_from,
const void *mem_to, struct held_lock *hlock)
printk( "[ BUG: held lock freed! ]\n");
printk( "-------------------------\n");
printk("%s/%d is freeing memory %p-%p, with a lock still held there!\n",
- curr->comm, curr->pid, mem_from, mem_to-1);
+ curr->comm, task_pid_nr(curr), mem_from, mem_to-1);
print_lock(hlock);
lockdep_print_held_locks(curr);
dump_stack();
}
+static inline int not_in_range(const void* mem_from, unsigned long mem_len,
+ const void* lock_from, unsigned long lock_len)
+{
+ return lock_from + lock_len <= mem_from ||
+ mem_from + mem_len <= lock_from;
+}
+
/*
* Called when kernel memory is freed (or unmapped), or if a lock
* is destroyed or reinitialized - this code checks whether there is
*/
void debug_check_no_locks_freed(const void *mem_from, unsigned long mem_len)
{
- const void *mem_to = mem_from + mem_len, *lock_from, *lock_to;
struct task_struct *curr = current;
struct held_lock *hlock;
unsigned long flags;
for (i = 0; i < curr->lockdep_depth; i++) {
hlock = curr->held_locks + i;
- lock_from = (void *)hlock->instance;
- lock_to = (void *)(hlock->instance + 1);
-
- if (!in_range(mem_from, lock_from, mem_to) &&
- !in_range(mem_from, lock_to, mem_to))
+ if (not_in_range(mem_from, mem_len, hlock->instance,
+ sizeof(*hlock->instance)))
continue;
- print_freed_lock_bug(curr, mem_from, mem_to, hlock);
+ print_freed_lock_bug(curr, mem_from, mem_from + mem_len, hlock);
break;
}
local_irq_restore(flags);
printk( "[ BUG: lock held at task exit time! ]\n");
printk( "-------------------------------------\n");
printk("%s/%d is exiting with locks still held!\n",
- curr->comm, curr->pid);
+ curr->comm, task_pid_nr(curr));
lockdep_print_held_locks(curr);
printk("\nstack backtrace:\n");
}
printk(" ignoring it.\n");
unlock = 0;
+ } else {
+ if (count != 10)
+ printk(KERN_CONT " locked it.\n");
}
- if (count != 10)
- printk(" locked it.\n");
do_each_thread(g, p) {
+ /*
+ * It's not reliable to print a task's held locks
+ * if it's not sleeping (or if it's not the current
+ * task):
+ */
+ if (p->state == TASK_RUNNING && p != current)
+ continue;
if (p->lockdep_depth)
lockdep_print_held_locks(p);
if (!unlock)
if (unlock)
read_unlock(&tasklist_lock);
}
-
EXPORT_SYMBOL_GPL(debug_show_all_locks);
-void debug_show_held_locks(struct task_struct *task)
+/*
+ * Careful: only use this function if you are sure that
+ * the task cannot run in parallel!
+ */
+void __debug_show_held_locks(struct task_struct *task)
{
if (unlikely(!debug_locks)) {
printk("INFO: lockdep is turned off.\n");
}
lockdep_print_held_locks(task);
}
+EXPORT_SYMBOL_GPL(__debug_show_held_locks);
+void debug_show_held_locks(struct task_struct *task)
+{
+ __debug_show_held_locks(task);
+}
EXPORT_SYMBOL_GPL(debug_show_held_locks);
+
+void lockdep_sys_exit(void)
+{
+ struct task_struct *curr = current;
+
+ if (unlikely(curr->lockdep_depth)) {
+ if (!debug_locks_off())
+ return;
+ printk("\n================================================\n");
+ printk( "[ BUG: lock held when returning to user space! ]\n");
+ printk( "------------------------------------------------\n");
+ printk("%s/%d is leaving the kernel with locks still held!\n",
+ curr->comm, curr->pid);
+ lockdep_print_held_locks(curr);
+ }
+}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff