tracing: Updates for 3.16

index 846888e..3cfeb66 100644
@@ -313,6 +313,11 @@ static void update_ftrace_function(void)
 	ftrace_trace_function = func;
 }
 
+int using_ftrace_ops_list_func(void)
+{
+	return ftrace_trace_function == ftrace_ops_list_func;
+}
+
 static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
 {
 	ops->next = *list;

index 5d2f07d..8624b50 100644
@@ -830,6 +830,7 @@ void ftrace_destroy_function_files(struct trace_array *tr);
 void ftrace_init_global_array_ops(struct trace_array *tr);
 void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func);
 void ftrace_reset_array_ops(struct trace_array *tr);
+int using_ftrace_ops_list_func(void);
 #else
 static inline int ftrace_trace_task(struct task_struct *task)
 {

index 21b320e..5aa9a5b 100644
@@ -85,8 +85,12 @@ check_stack(unsigned long ip, unsigned long *stack)
 
 	max_stack_size = this_size;
 
-	max_stack_trace.nr_entries	= 0;
-	max_stack_trace.skip		= 3;
+	max_stack_trace.nr_entries = 0;
+
+	if (using_ftrace_ops_list_func())
+		max_stack_trace.skip = 4;
+	else
+		max_stack_trace.skip = 3;
 
 	save_stack_trace(&max_stack_trace);
 

index 3cfeb66..34b098bf 100644
@@ -3542,8 +3542,7 @@ int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
 }
 EXPORT_SYMBOL_GPL(ftrace_set_notrace);
 /**
- * ftrace_set_filter - set a function to filter on in ftrace
- * @ops - the ops to set the filter with
+ * ftrace_set_global_filter - set a function to filter on with global tracers
  * @buf - the string that holds the function filter text.
  * @len - the length of the string.
  * @reset - non zero to reset all filters before applying this filter.

@@ -3558,8 +3557,7 @@ void ftrace_set_global_filter(unsigned char *buf, int len, int reset)
 EXPORT_SYMBOL_GPL(ftrace_set_global_filter);
 
 /**
- * ftrace_set_notrace - set a function to not trace in ftrace
- * @ops - the ops to set the notrace filter with
+ * ftrace_set_global_notrace - set a function to not trace with global tracers
  * @buf - the string that holds the function notrace text.
  * @len - the length of the string.
  * @reset - non zero to reset all filters before applying this filter.

index cb41e98..e058c60 100644
@@ -4237,15 +4237,6 @@ static int tracing_wait_pipe(struct file *filp)
 			return -EAGAIN;
 		}
 
-		mutex_unlock(&iter->mutex);
-
-		iter->trace->wait_pipe(iter);
-
-		mutex_lock(&iter->mutex);
-
-		if (signal_pending(current))
-			return -EINTR;
-
 		/*
 		 * We block until we read something and tracing is disabled.
 		 * We still block if tracing is disabled, but we have never

@@ -4257,6 +4248,15 @@ static int tracing_wait_pipe(struct file *filp)
 		 */
 		if (!tracing_is_on() && iter->pos)
 			break;
+
+		mutex_unlock(&iter->mutex);
+
+		iter->trace->wait_pipe(iter);
+
+		mutex_lock(&iter->mutex);
+
+		if (signal_pending(current))
+			return -EINTR;
 	}
 
 	return 1;

index e058c60..4c392c8 100644
@@ -1085,7 +1085,7 @@ update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu)
 }
 #endif /* CONFIG_TRACER_MAX_TRACE */
 
-static void default_wait_pipe(struct trace_iterator *iter)
+static void wait_on_pipe(struct trace_iterator *iter)
 {
 	/* Iterators are static, they should be filled or empty */
 	if (trace_buffer_iter(iter, iter->cpu_file))

@@ -1202,8 +1202,6 @@ int register_tracer(struct tracer *type)
 	else
 		if (!type->flags->opts)
 			type->flags->opts = dummy_tracer_opt;
-	if (!type->wait_pipe)
-		type->wait_pipe = default_wait_pipe;
 
 	ret = run_tracer_selftest(type);
 	if (ret < 0)

@@ -4207,25 +4205,6 @@ tracing_poll_pipe(struct file *filp, poll_table *poll_table)
 	return trace_poll(iter, filp, poll_table);
 }
 
-/*
- * This is a make-shift waitqueue.
- * A tracer might use this callback on some rare cases:
- *
- *  1) the current tracer might hold the runqueue lock when it wakes up
- *     a reader, hence a deadlock (sched, function, and function graph tracers)
- *  2) the function tracers, trace all functions, we don't want
- *     the overhead of calling wake_up and friends
- *     (and tracing them too)
- *
- *     Anyway, this is really very primitive wakeup.
- */
-void poll_wait_pipe(struct trace_iterator *iter)
-{
-	set_current_state(TASK_INTERRUPTIBLE);
-	/* sleep for 100 msecs, and try again. */
-	schedule_timeout(HZ / 10);
-}
-
 /* Must be called with trace_types_lock mutex held. */
 static int tracing_wait_pipe(struct file *filp)
 {

@@ -4251,7 +4230,7 @@ static int tracing_wait_pipe(struct file *filp)
 
 		mutex_unlock(&iter->mutex);
 
-		iter->trace->wait_pipe(iter);
+		wait_on_pipe(iter);
 
 		mutex_lock(&iter->mutex);
 

@@ -5179,7 +5158,7 @@ tracing_buffers_read(struct file *filp, char __user *ubuf,
 				goto out_unlock;
 			}
 			mutex_unlock(&trace_types_lock);
-			iter->trace->wait_pipe(iter);
+			wait_on_pipe(iter);
 			mutex_lock(&trace_types_lock);
 			if (signal_pending(current)) {
 				size = -EINTR;

@@ -5390,7 +5369,7 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
 			goto out;
 		}
 		mutex_unlock(&trace_types_lock);
-		iter->trace->wait_pipe(iter);
+		wait_on_pipe(iter);
 		mutex_lock(&trace_types_lock);
 		if (signal_pending(current)) {
 			ret = -EINTR;

index 8624b50..3b3e09e 100644
@@ -338,7 +338,6 @@ struct tracer_flags {
  * @stop: called when tracing is paused (echo 0 > tracing_enabled)
  * @open: called when the trace file is opened
  * @pipe_open: called when the trace_pipe file is opened
- * @wait_pipe: override how the user waits for traces on trace_pipe
  * @close: called when the trace file is released
  * @pipe_close: called when the trace_pipe file is released
  * @read: override the default read callback on trace_pipe

@@ -357,7 +356,6 @@ struct tracer {
 	void			(*stop)(struct trace_array *tr);
 	void			(*open)(struct trace_iterator *iter);
 	void			(*pipe_open)(struct trace_iterator *iter);
-	void			(*wait_pipe)(struct trace_iterator *iter);
 	void			(*close)(struct trace_iterator *iter);
 	void			(*pipe_close)(struct trace_iterator *iter);
 	ssize_t			(*read)(struct trace_iterator *iter,

@@ -566,8 +564,6 @@ void trace_init_global_iter(struct trace_iterator *iter);
 
 void tracing_iter_reset(struct trace_iterator *iter, int cpu);
 
-void poll_wait_pipe(struct trace_iterator *iter);
-
 void tracing_sched_switch_trace(struct trace_array *tr,
 				struct task_struct *prev,
 				struct task_struct *next,

index 2d9482b..57f0ec9 100644
@@ -252,7 +252,6 @@ static struct tracer function_trace __tracer_data =
 	.init		= function_trace_init,
 	.reset		= function_trace_reset,
 	.start		= function_trace_start,
-	.wait_pipe	= poll_wait_pipe,
 	.flags		= &func_flags,
 	.set_flag	= func_set_flag,
 	.allow_instances = true,

index deff112..b86dd4d 100644
@@ -1505,7 +1505,6 @@ static struct tracer graph_trace __tracer_data = {
 	.pipe_open	= graph_trace_open,
 	.close		= graph_trace_close,
 	.pipe_close	= graph_trace_close,
-	.wait_pipe	= poll_wait_pipe,
 	.init		= graph_trace_init,
 	.reset		= graph_trace_reset,
 	.print_line	= print_graph_function,

index 69a5cc9..fcf0a9e 100644
@@ -91,7 +91,6 @@ struct tracer nop_trace __read_mostly =
 	.name		= "nop",
 	.init		= nop_trace_init,
 	.reset		= nop_trace_reset,
-	.wait_pipe	= poll_wait_pipe,
 #ifdef CONFIG_FTRACE_SELFTEST
 	.selftest	= trace_selftest_startup_nop,
 #endif

index 1573c03..19bd892 100644
@@ -705,7 +705,6 @@ static struct tracer wakeup_rt_tracer __read_mostly =
 	.reset		= wakeup_tracer_reset,
 	.start		= wakeup_tracer_start,
 	.stop		= wakeup_tracer_stop,
-	.wait_pipe	= poll_wait_pipe,
 	.print_max	= true,
 	.print_header	= wakeup_print_header,
 	.print_line	= wakeup_print_line,

@@ -728,7 +727,6 @@ static struct tracer wakeup_dl_tracer __read_mostly =
 	.reset		= wakeup_tracer_reset,
 	.start		= wakeup_tracer_start,
 	.stop		= wakeup_tracer_stop,
-	.wait_pipe	= poll_wait_pipe,
 	.print_max	= true,
 	.print_header	= wakeup_print_header,
 	.print_line	= wakeup_print_line,