Merge branch 'master' into for-linus

15 files changed, 185 insertions, 89 deletions

diff --git a/kernel/fork.c b/kernel/fork.c
index 29b532e718f..466531eb92c 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1269,6 +1269,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 	write_unlock_irq(&tasklist_lock);
 	proc_fork_connector(p);
 	cgroup_post_fork(p);
+	perf_counter_fork(p);
 	return p;
 
 bad_fork_free_pid:
@@ -1410,9 +1411,6 @@ long do_fork(unsigned long clone_flags,
 			init_completion(&vfork);
 		}
 
-		if (!(clone_flags & CLONE_THREAD))
-			perf_counter_fork(p);
-
 		audit_finish_fork(p);
 		tracehook_report_clone(regs, clone_flags, nr, p);
 
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 16b5739c516..0540948e29a 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -694,7 +694,7 @@ int __kprobes register_kprobe(struct kprobe *p)
 	p->addr = addr;
 
 	preempt_disable();
-	if (!__kernel_text_address((unsigned long) p->addr) ||
+	if (!kernel_text_address((unsigned long) p->addr) ||
 	    in_kprobes_functions((unsigned long) p->addr)) {
 		preempt_enable();
 		return -EINVAL;
diff --git a/kernel/panic.c b/kernel/panic.c
index 984b3ecbd72..512ab73b0ca 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -301,6 +301,7 @@ int oops_may_print(void)
  */
 void oops_enter(void)
 {
+	tracing_off();
 	/* can't trust the integrity of the kernel anymore: */
 	debug_locks_off();
 	do_oops_enter_exit();
diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c
index 95093104195..199ed477131 100644
--- a/kernel/perf_counter.c
+++ b/kernel/perf_counter.c
@@ -42,6 +42,7 @@ static int perf_overcommit __read_mostly = 1;
 static atomic_t nr_counters __read_mostly;
 static atomic_t nr_mmap_counters __read_mostly;
 static atomic_t nr_comm_counters __read_mostly;
+static atomic_t nr_task_counters __read_mostly;
 
 /*
  * perf counter paranoia level:
@@ -1654,6 +1655,8 @@ static void free_counter(struct perf_counter *counter)
 			atomic_dec(&nr_mmap_counters);
 		if (counter->attr.comm)
 			atomic_dec(&nr_comm_counters);
+		if (counter->attr.task)
+			atomic_dec(&nr_task_counters);
 	}
 
 	if (counter->destroy)
@@ -1688,6 +1691,18 @@ static int perf_release(struct inode *inode, struct file *file)
 	return 0;
 }
 
+static u64 perf_counter_read_tree(struct perf_counter *counter)
+{
+	struct perf_counter *child;
+	u64 total = 0;
+
+	total += perf_counter_read(counter);
+	list_for_each_entry(child, &counter->child_list, child_list)
+		total += perf_counter_read(child);
+
+	return total;
+}
+
 /*
  * Read the performance counter - simple non blocking version for now
  */
@@ -1707,7 +1722,7 @@ perf_read_hw(struct perf_counter *counter, char __user *buf, size_t count)
 
 	WARN_ON_ONCE(counter->ctx->parent_ctx);
 	mutex_lock(&counter->child_mutex);
-	values[0] = perf_counter_read(counter);
+	values[0] = perf_counter_read_tree(counter);
 	n = 1;
 	if (counter->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
 		values[n++] = counter->total_time_enabled +
@@ -2819,10 +2834,12 @@ perf_counter_read_event(struct perf_counter *counter,
 }
 
 /*
- * fork tracking
+ * task tracking -- fork/exit
+ *
+ * enabled by: attr.comm | attr.mmap | attr.task
  */
 
-struct perf_fork_event {
+struct perf_task_event {
 	struct task_struct	*task;
 
 	struct {
@@ -2830,37 +2847,42 @@ struct perf_fork_event {
 
 		u32				pid;
 		u32				ppid;
+		u32				tid;
+		u32				ptid;
 	} event;
 };
 
-static void perf_counter_fork_output(struct perf_counter *counter,
-				     struct perf_fork_event *fork_event)
+static void perf_counter_task_output(struct perf_counter *counter,
+				     struct perf_task_event *task_event)
 {
 	struct perf_output_handle handle;
-	int size = fork_event->event.header.size;
-	struct task_struct *task = fork_event->task;
+	int size = task_event->event.header.size;
+	struct task_struct *task = task_event->task;
 	int ret = perf_output_begin(&handle, counter, size, 0, 0);
 
 	if (ret)
 		return;
 
-	fork_event->event.pid = perf_counter_pid(counter, task);
-	fork_event->event.ppid = perf_counter_pid(counter, task->real_parent);
+	task_event->event.pid = perf_counter_pid(counter, task);
+	task_event->event.ppid = perf_counter_pid(counter, task->real_parent);
 
-	perf_output_put(&handle, fork_event->event);
+	task_event->event.tid = perf_counter_tid(counter, task);
+	task_event->event.ptid = perf_counter_tid(counter, task->real_parent);
+
+	perf_output_put(&handle, task_event->event);
 	perf_output_end(&handle);
 }
 
-static int perf_counter_fork_match(struct perf_counter *counter)
+static int perf_counter_task_match(struct perf_counter *counter)
 {
-	if (counter->attr.comm || counter->attr.mmap)
+	if (counter->attr.comm || counter->attr.mmap || counter->attr.task)
 		return 1;
 
 	return 0;
 }
 
-static void perf_counter_fork_ctx(struct perf_counter_context *ctx,
-				  struct perf_fork_event *fork_event)
+static void perf_counter_task_ctx(struct perf_counter_context *ctx,
+				  struct perf_task_event *task_event)
 {
 	struct perf_counter *counter;
 
@@ -2869,19 +2891,19 @@ static void perf_counter_fork_ctx(struct perf_counter_context *ctx,
 
 	rcu_read_lock();
 	list_for_each_entry_rcu(counter, &ctx->event_list, event_entry) {
-		if (perf_counter_fork_match(counter))
-			perf_counter_fork_output(counter, fork_event);
+		if (perf_counter_task_match(counter))
+			perf_counter_task_output(counter, task_event);
 	}
 	rcu_read_unlock();
 }
 
-static void perf_counter_fork_event(struct perf_fork_event *fork_event)
+static void perf_counter_task_event(struct perf_task_event *task_event)
 {
 	struct perf_cpu_context *cpuctx;
 	struct perf_counter_context *ctx;
 
 	cpuctx = &get_cpu_var(perf_cpu_context);
-	perf_counter_fork_ctx(&cpuctx->ctx, fork_event);
+	perf_counter_task_ctx(&cpuctx->ctx, task_event);
 	put_cpu_var(perf_cpu_context);
 
 	rcu_read_lock();
@@ -2891,32 +2913,40 @@ static void perf_counter_fork_event(struct perf_fork_event *fork_event)
 	 */
 	ctx = rcu_dereference(current->perf_counter_ctxp);
 	if (ctx)
-		perf_counter_fork_ctx(ctx, fork_event);
+		perf_counter_task_ctx(ctx, task_event);
 	rcu_read_unlock();
 }
 
-void perf_counter_fork(struct task_struct *task)
+static void perf_counter_task(struct task_struct *task, int new)
 {
-	struct perf_fork_event fork_event;
+	struct perf_task_event task_event;
 
 	if (!atomic_read(&nr_comm_counters) &&
-	    !atomic_read(&nr_mmap_counters))
+	    !atomic_read(&nr_mmap_counters) &&
+	    !atomic_read(&nr_task_counters))
 		return;
 
-	fork_event = (struct perf_fork_event){
+	task_event = (struct perf_task_event){
 		.task	= task,
 		.event  = {
 			.header = {
-				.type = PERF_EVENT_FORK,
+				.type = new ? PERF_EVENT_FORK : PERF_EVENT_EXIT,
 				.misc = 0,
-				.size = sizeof(fork_event.event),
+				.size = sizeof(task_event.event),
 			},
 			/* .pid  */
 			/* .ppid */
+			/* .tid  */
+			/* .ptid */
 		},
 	};
 
-	perf_counter_fork_event(&fork_event);
+	perf_counter_task_event(&task_event);
+}
+
+void perf_counter_fork(struct task_struct *task)
+{
+	perf_counter_task(task, 1);
 }
 
 /*
@@ -3875,6 +3905,8 @@ done:
 			atomic_inc(&nr_mmap_counters);
 		if (counter->attr.comm)
 			atomic_inc(&nr_comm_counters);
+		if (counter->attr.task)
+			atomic_inc(&nr_task_counters);
 	}
 
 	return counter;
@@ -4236,8 +4268,10 @@ void perf_counter_exit_task(struct task_struct *child)
 	struct perf_counter_context *child_ctx;
 	unsigned long flags;
 
-	if (likely(!child->perf_counter_ctxp))
+	if (likely(!child->perf_counter_ctxp)) {
+		perf_counter_task(child, 0);
 		return;
+	}
 
 	local_irq_save(flags);
 	/*
@@ -4255,15 +4289,22 @@ void perf_counter_exit_task(struct task_struct *child)
 	 * incremented the context's refcount before we do put_ctx below.
 	 */
 	spin_lock(&child_ctx->lock);
-	child->perf_counter_ctxp = NULL;
 	/*
 	 * If this context is a clone; unclone it so it can't get
 	 * swapped to another process while we're removing all
 	 * the counters from it.
 	 */
 	unclone_ctx(child_ctx);
-	spin_unlock(&child_ctx->lock);
-	local_irq_restore(flags);
+	spin_unlock_irqrestore(&child_ctx->lock, flags);
+
+	/*
+	 * Report the task dead after unscheduling the counters so that we
+	 * won't get any samples after PERF_EVENT_EXIT. We can however still
+	 * get a few PERF_EVENT_READ events.
+	 */
+	perf_counter_task(child, 0);
+
+	child->perf_counter_ctxp = NULL;
 
 	/*
 	 * We can recurse on the same lock type through:
diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c
index 052ec4d195c..d089d052c4a 100644
--- a/kernel/posix-timers.c
+++ b/kernel/posix-timers.c
@@ -202,6 +202,12 @@ static int no_timer_create(struct k_itimer *new_timer)
 	return -EOPNOTSUPP;
 }
 
+static int no_nsleep(const clockid_t which_clock, int flags,
+		     struct timespec *tsave, struct timespec __user *rmtp)
+{
+	return -EOPNOTSUPP;
+}
+
 /*
  * Return nonzero if we know a priori this clockid_t value is bogus.
  */
@@ -254,6 +260,7 @@ static __init int init_posix_timers(void)
 		.clock_get = posix_get_monotonic_raw,
 		.clock_set = do_posix_clock_nosettime,
 		.timer_create = no_timer_create,
+		.nsleep = no_nsleep,
 	};
 
 	register_posix_clock(CLOCK_REALTIME, &clock_realtime);
diff --git a/kernel/sched_cpupri.c b/kernel/sched_cpupri.c
index e6c251790dd..d014efbf947 100644
--- a/kernel/sched_cpupri.c
+++ b/kernel/sched_cpupri.c
@@ -81,8 +81,21 @@ int cpupri_find(struct cpupri *cp, struct task_struct *p,
 		if (cpumask_any_and(&p->cpus_allowed, vec->mask) >= nr_cpu_ids)
 			continue;
 
-		if (lowest_mask)
+		if (lowest_mask) {
 			cpumask_and(lowest_mask, &p->cpus_allowed, vec->mask);
+
+			/*
+			 * We have to ensure that we have at least one bit
+			 * still set in the array, since the map could have
+			 * been concurrently emptied between the first and
+			 * second reads of vec->mask.  If we hit this
+			 * condition, simply act as though we never hit this
+			 * priority level and continue on.
+			 */
+			if (cpumask_any(lowest_mask) >= nr_cpu_ids)
+				continue;
+		}
+
 		return 1;
 	}
 
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 9ffb2b2ceba..652e8bdef9a 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -611,9 +611,13 @@ account_entity_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se)
 static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se)
 {
 #ifdef CONFIG_SCHEDSTATS
+	struct task_struct *tsk = NULL;
+
+	if (entity_is_task(se))
+		tsk = task_of(se);
+
 	if (se->sleep_start) {
 		u64 delta = rq_of(cfs_rq)->clock - se->sleep_start;
-		struct task_struct *tsk = task_of(se);
 
 		if ((s64)delta < 0)
 			delta = 0;
@@ -624,11 +628,11 @@ static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se)
 		se->sleep_start = 0;
 		se->sum_sleep_runtime += delta;
 
-		account_scheduler_latency(tsk, delta >> 10, 1);
+		if (tsk)
+			account_scheduler_latency(tsk, delta >> 10, 1);
 	}
 	if (se->block_start) {
 		u64 delta = rq_of(cfs_rq)->clock - se->block_start;
-		struct task_struct *tsk = task_of(se);
 
 		if ((s64)delta < 0)
 			delta = 0;
@@ -639,17 +643,19 @@ static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se)
 		se->block_start = 0;
 		se->sum_sleep_runtime += delta;
 
-		/*
-		 * Blocking time is in units of nanosecs, so shift by 20 to
-		 * get a milliseconds-range estimation of the amount of
-		 * time that the task spent sleeping:
-		 */
-		if (unlikely(prof_on == SLEEP_PROFILING)) {
-
-			profile_hits(SLEEP_PROFILING, (void *)get_wchan(tsk),
-				     delta >> 20);
+		if (tsk) {
+			/*
+			 * Blocking time is in units of nanosecs, so shift by
+			 * 20 to get a milliseconds-range estimation of the
+			 * amount of time that the task spent sleeping:
+			 */
+			if (unlikely(prof_on == SLEEP_PROFILING)) {
+				profile_hits(SLEEP_PROFILING,
+						(void *)get_wchan(tsk),
+						delta >> 20);
+			}
+			account_scheduler_latency(tsk, delta >> 10, 0);
 		}
-		account_scheduler_latency(tsk, delta >> 10, 0);
 	}
 #endif
 }
diff --git a/kernel/signal.c b/kernel/signal.c
index ccf1ceedaeb..64c5deeaca5 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -2454,11 +2454,9 @@ do_sigaltstack (const stack_t __user *uss, stack_t __user *uoss, unsigned long s
 	stack_t oss;
 	int error;
 
-	if (uoss) {
-		oss.ss_sp = (void __user *) current->sas_ss_sp;
-		oss.ss_size = current->sas_ss_size;
-		oss.ss_flags = sas_ss_flags(sp);
-	}
+	oss.ss_sp = (void __user *) current->sas_ss_sp;
+	oss.ss_size = current->sas_ss_size;
+	oss.ss_flags = sas_ss_flags(sp);
 
 	if (uss) {
 		void __user *ss_sp;
@@ -2466,10 +2464,12 @@ do_sigaltstack (const stack_t __user *uss, stack_t __user *uoss, unsigned long s
 		int ss_flags;
 
 		error = -EFAULT;
-		if (!access_ok(VERIFY_READ, uss, sizeof(*uss))
-		    || __get_user(ss_sp, &uss->ss_sp)
-		    || __get_user(ss_flags, &uss->ss_flags)
-		    || __get_user(ss_size, &uss->ss_size))
+		if (!access_ok(VERIFY_READ, uss, sizeof(*uss)))
+			goto out;
+		error = __get_user(ss_sp, &uss->ss_sp) |
+			__get_user(ss_flags, &uss->ss_flags) |
+			__get_user(ss_size, &uss->ss_size);
+		if (error)
 			goto out;
 
 		error = -EPERM;
@@ -2501,13 +2501,16 @@ do_sigaltstack (const stack_t __user *uss, stack_t __user *uoss, unsigned long s
 		current->sas_ss_size = ss_size;
 	}
 
+	error = 0;
 	if (uoss) {
 		error = -EFAULT;
-		if (copy_to_user(uoss, &oss, sizeof(oss)))
+		if (!access_ok(VERIFY_WRITE, uoss, sizeof(*uoss)))
 			goto out;
+		error = __put_user(oss.ss_sp, &uoss->ss_sp) |
+			__put_user(oss.ss_size, &uoss->ss_size) |
+			__put_user(oss.ss_flags, &uoss->ss_flags);
 	}
 
-	error = 0;
 out:
 	return error;
 }
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 4521c77d1a1..1e1d23c2630 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1662,7 +1662,7 @@ ftrace_regex_open(struct inode *inode, struct file *file, int enable)
 
 	mutex_lock(&ftrace_regex_lock);
 	if ((file->f_mode & FMODE_WRITE) &&
-	    !(file->f_flags & O_APPEND))
+	    (file->f_flags & O_TRUNC))
 		ftrace_filter_reset(enable);
 
 	if (file->f_mode & FMODE_READ) {
@@ -2577,7 +2577,7 @@ ftrace_graph_open(struct inode *inode, struct file *file)
 
 	mutex_lock(&graph_lock);
 	if ((file->f_mode & FMODE_WRITE) &&
-	    !(file->f_flags & O_APPEND)) {
+	    (file->f_flags & O_TRUNC)) {
 		ftrace_graph_count = 0;
 		memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs));
 	}
@@ -2596,6 +2596,14 @@ ftrace_graph_open(struct inode *inode, struct file *file)
 }
 
 static int
+ftrace_graph_release(struct inode *inode, struct file *file)
+{
+	if (file->f_mode & FMODE_READ)
+		seq_release(inode, file);
+	return 0;
+}
+
+static int
 ftrace_set_func(unsigned long *array, int *idx, char *buffer)
 {
 	struct dyn_ftrace *rec;
@@ -2724,9 +2732,10 @@ ftrace_graph_write(struct file *file, const char __user *ubuf,
 }
 
 static const struct file_operations ftrace_graph_fops = {
-	.open = ftrace_graph_open,
-	.read = seq_read,
-	.write = ftrace_graph_write,
+	.open		= ftrace_graph_open,
+	.read		= seq_read,
+	.write		= ftrace_graph_write,
+	.release	= ftrace_graph_release,
 };
 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 8bc8d8afea6..8930e39b9d8 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2031,7 +2031,7 @@ static int tracing_open(struct inode *inode, struct file *file)
 
 	/* If this file was open for write, then erase contents */
 	if ((file->f_mode & FMODE_WRITE) &&
-	    !(file->f_flags & O_APPEND)) {
+	    (file->f_flags & O_TRUNC)) {
 		long cpu = (long) inode->i_private;
 
 		if (cpu == TRACE_PIPE_ALL_CPU)
@@ -3085,7 +3085,8 @@ tracing_fill_pipe_page(size_t rem, struct trace_iterator *iter)
 			break;
 		}
 
-		trace_consume(iter);
+		if (ret != TRACE_TYPE_NO_CONSUME)
+			trace_consume(iter);
 		rem -= count;
 		if (!find_next_entry_inc(iter))	{
 			rem = 0;
@@ -4233,8 +4234,11 @@ static void __ftrace_dump(bool disable_tracing)
 		iter.pos = -1;
 
 		if (find_next_entry_inc(&iter) != NULL) {
-			print_trace_line(&iter);
-			trace_consume(&iter);
+			int ret;
+
+			ret = print_trace_line(&iter);
+			if (ret != TRACE_TYPE_NO_CONSUME)
+				trace_consume(&iter);
 		}
 
 		trace_printk_seq(&iter.seq);
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 53c8fd376a8..23d2972b22d 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -376,7 +376,7 @@ ftrace_event_seq_open(struct inode *inode, struct file *file)
 	const struct seq_operations *seq_ops;
 
 	if ((file->f_mode & FMODE_WRITE) &&
-	    !(file->f_flags & O_APPEND))
+	    (file->f_flags & O_TRUNC))
 		ftrace_clear_events();
 
 	seq_ops = inode->i_private;
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index d2249abafb5..420ec348757 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -843,9 +843,16 @@ print_graph_function(struct trace_iterator *iter)
 
 	switch (entry->type) {
 	case TRACE_GRAPH_ENT: {
-		struct ftrace_graph_ent_entry *field;
+		/*
+		 * print_graph_entry() may consume the current event,
+		 * thus @field may become invalid, so we need to save it.
+		 * sizeof(struct ftrace_graph_ent_entry) is very small,
+		 * it can be safely saved at the stack.
+		 */
+		struct ftrace_graph_ent_entry *field, saved;
 		trace_assign_type(field, entry);
-		return print_graph_entry(field, s, iter);
+		saved = *field;
+		return print_graph_entry(&saved, s, iter);
 	}
 	case TRACE_GRAPH_RET: {
 		struct ftrace_graph_ret_entry *field;
diff --git a/kernel/trace/trace_printk.c b/kernel/trace/trace_printk.c
index 7b627811082..687699d365a 100644
--- a/kernel/trace/trace_printk.c
+++ b/kernel/trace/trace_printk.c
@@ -176,7 +176,7 @@ static int t_show(struct seq_file *m, void *v)
 	const char *str = *fmt;
 	int i;
 
-	seq_printf(m, "0x%lx : \"", (unsigned long)fmt);
+	seq_printf(m, "0x%lx : \"", *(unsigned long *)fmt);
 
 	/*
 	 * Tabs and new lines need to be converted.
diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index e644af91012..6a2a9d484cd 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -301,17 +301,14 @@ static const struct seq_operations stack_trace_seq_ops = {
 
 static int stack_trace_open(struct inode *inode, struct file *file)
 {
-	int ret;
-
-	ret = seq_open(file, &stack_trace_seq_ops);
-
-	return ret;
+	return seq_open(file, &stack_trace_seq_ops);
 }
 
 static const struct file_operations stack_trace_fops = {
 	.open		= stack_trace_open,
 	.read		= seq_read,
 	.llseek		= seq_lseek,
+	.release	= seq_release,
 };
 
 int
diff --git a/kernel/trace/trace_stat.c b/kernel/trace/trace_stat.c
index e66f5e49334..aea321c82fa 100644
--- a/kernel/trace/trace_stat.c
+++ b/kernel/trace/trace_stat.c
@@ -73,7 +73,7 @@ static struct rb_node *release_next(struct rb_node *node)
 	}
 }
 
-static void reset_stat_session(struct stat_session *session)
+static void __reset_stat_session(struct stat_session *session)
 {
 	struct rb_node *node = session->stat_root.rb_node;
 
@@ -83,10 +83,17 @@ static void reset_stat_session(struct stat_session *session)
 	session->stat_root = RB_ROOT;
 }
 
+static void reset_stat_session(struct stat_session *session)
+{
+	mutex_lock(&session->stat_mutex);
+	__reset_stat_session(session);
+	mutex_unlock(&session->stat_mutex);
+}
+
 static void destroy_session(struct stat_session *session)
 {
 	debugfs_remove(session->file);
-	reset_stat_session(session);
+	__reset_stat_session(session);
 	mutex_destroy(&session->stat_mutex);
 	kfree(session);
 }
@@ -150,7 +157,7 @@ static int stat_seq_init(struct stat_session *session)
 	int i;
 
 	mutex_lock(&session->stat_mutex);
-	reset_stat_session(session);
+	__reset_stat_session(session);
 
 	if (!ts->stat_cmp)
 		ts->stat_cmp = dummy_cmp;
@@ -183,7 +190,7 @@ exit:
 	return ret;
 
 exit_free_rbtree:
-	reset_stat_session(session);
+	__reset_stat_session(session);
 	mutex_unlock(&session->stat_mutex);
 	return ret;
 }
@@ -250,16 +257,21 @@ static const struct seq_operations trace_stat_seq_ops = {
 static int tracing_stat_open(struct inode *inode, struct file *file)
 {
 	int ret;
-
+	struct seq_file *m;
 	struct stat_session *session = inode->i_private;
 
+	ret = stat_seq_init(session);
+	if (ret)
+		return ret;
+
 	ret = seq_open(file, &trace_stat_seq_ops);
-	if (!ret) {
-		struct seq_file *m = file->private_data;
-		m->private = session;
-		ret = stat_seq_init(session);
+	if (ret) {
+		reset_stat_session(session);
+		return ret;
 	}
 
+	m = file->private_data;
+	m->private = session;
 	return ret;
 }
 
@@ -270,11 +282,9 @@ static int tracing_stat_release(struct inode *i, struct file *f)
 {
 	struct stat_session *session = i->i_private;
 
-	mutex_lock(&session->stat_mutex);
 	reset_stat_session(session);
-	mutex_unlock(&session->stat_mutex);
 
-	return 0;
+	return seq_release(i, f);
 }
 
 static const struct file_operations tracing_stat_fops = {