Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (184 commits)
  perf probe: Clean up probe_point_lazy_walker() return value
  tracing: Fix irqoff selftest expanding max buffer
  tracing: Align 4 byte ints together in struct tracer
  tracing: Export trace_set_clr_event()
  tracing: Explain about unstable clock on resume with ring buffer warning
  ftrace/graph: Trace function entry before updating index
  ftrace: Add .ref.text as one of the safe areas to trace
  tracing: Adjust conditional expression latency formatting.
  tracing: Fix event alignment: skb:kfree_skb
  tracing: Fix event alignment: mce:mce_record
  tracing: Fix event alignment: kvm:kvm_hv_hypercall
  tracing: Fix event alignment: module:module_request
  tracing: Fix event alignment: ftrace:context_switch and ftrace:wakeup
  tracing: Remove lock_depth from event entry
  perf header: Stop using 'self'
  perf session: Use evlist/evsel for managing perf.data attributes
  perf top: Don't let events to eat up whole header line
  perf top: Fix events overflow in top command
  ring-buffer: Remove unused #include <linux/trace_irq.h>
  tracing: Add an 'overwrite' trace_option.
  ...

1 files changed, 4 insertions, 1 deletions

diff --git a/tools/perf/util/ui/helpline.c b/tools/perf/util/ui/helpline.c
index 8d79daa4458a..f36d2ff509ed 100644
--- a/tools/perf/util/ui/helpline.c
+++ b/tools/perf/util/ui/helpline.c
@@ -5,6 +5,7 @@
 
 #include "../debug.h"
 #include "helpline.h"
+#include "ui.h"
 
 void ui_helpline__pop(void)
 {
@@ -55,7 +56,8 @@ int ui_helpline__show_help(const char *format, va_list ap)
 	int ret;
 	static int backlog;
 
-        ret = vsnprintf(ui_helpline__last_msg + backlog,
+	pthread_mutex_lock(&ui__lock);
+	ret = vsnprintf(ui_helpline__last_msg + backlog,
 			sizeof(ui_helpline__last_msg) - backlog, format, ap);
 	backlog += ret;
 
@@ -64,6 +66,7 @@ int ui_helpline__show_help(const char *format, va_list ap)
 		newtRefresh();
 		backlog = 0;
 	}
+	pthread_mutex_unlock(&ui__lock);
 
 	return ret;
 }