tracing: Fix userstacktrace option for instances

When the instances were able to use their own options, the userstacktrace
option was left hardcoded for the top level. This made the instance
userstacktrace option bascially into a nop, and will confuse users that set
it, but nothing happens (I was confused when it happened to me!)

Cc: stable@vger.kernel.org
Fixes: 1627014 ("tracing: Add trace options for core options to instances")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

kernel/trace/trace.c

@@ -163,7 +163,8 @@ static union trace_eval_map_item *trace_eval_maps;
 #endif /* CONFIG_TRACE_EVAL_MAP_FILE */
 
 int tracing_set_tracer(struct trace_array *tr, const char *buf);
-static void ftrace_trace_userstack(struct trace_buffer *buffer,
+static void ftrace_trace_userstack(struct trace_array *tr,
+				   struct trace_buffer *buffer,
 				   unsigned long flags, int pc);
 
 #define MAX_TRACER_SIZE		100
@@ -2870,7 +2871,7 @@ void trace_buffer_unlock_commit_regs(struct trace_array *tr,
 	 * two. They are not that meaningful.
 	 */
 	ftrace_trace_stack(tr, buffer, flags, regs ? 0 : STACK_SKIP, pc, regs);
-	ftrace_trace_userstack(buffer, flags, pc);
+	ftrace_trace_userstack(tr, buffer, flags, pc);
 }
 
 /*
@@ -3056,13 +3057,14 @@ EXPORT_SYMBOL_GPL(trace_dump_stack);
 static DEFINE_PER_CPU(int, user_stack_count);
 
 static void
-ftrace_trace_userstack(struct trace_buffer *buffer, unsigned long flags, int pc)
+ftrace_trace_userstack(struct trace_array *tr,
+		       struct trace_buffer *buffer, unsigned long flags, int pc)
 {
 	struct trace_event_call *call = &event_user_stack;
 	struct ring_buffer_event *event;
 	struct userstack_entry *entry;
 
-	if (!(global_trace.trace_flags & TRACE_ITER_USERSTACKTRACE))
+	if (!(tr->trace_flags & TRACE_ITER_USERSTACKTRACE))
 		return;
 
 	/*
@@ -3101,7 +3103,8 @@ ftrace_trace_userstack(struct trace_buffer *buffer, unsigned long flags, int pc)
 	preempt_enable();
 }
 #else /* CONFIG_USER_STACKTRACE_SUPPORT */
-static void ftrace_trace_userstack(struct trace_buffer *buffer,
+static void ftrace_trace_userstack(struct trace_array *tr,
+				   struct trace_buffer *buffer,
 				   unsigned long flags, int pc)
 {
 }