[PATCH 4.9 45/63] tracing: Use cpumask_available() to check if cpumask variable may be used

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Matthias Kaehlcke <mka@xxxxxxxxxxxx>

commit 4dbbe2d8e95c351157f292ece067f985c30c7b53 upstream.

This fixes the following clang warning:

kernel/trace/trace.c:3231:12: warning: address of array 'iter->started'
  will always evaluate to 'true' [-Wpointer-bool-conversion]
        if (iter->started)

Link: http://lkml.kernel.org/r/20170421234110.117075-1-mka@xxxxxxxxxxxx

Signed-off-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
Signed-off-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 kernel/trace/trace.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -3022,13 +3022,14 @@ static void test_cpu_buff_start(struct t
 	if (!(iter->iter_flags & TRACE_FILE_ANNOTATE))
 		return;
 
-	if (iter->started && cpumask_test_cpu(iter->cpu, iter->started))
+	if (cpumask_available(iter->started) &&
+	    cpumask_test_cpu(iter->cpu, iter->started))
 		return;
 
 	if (per_cpu_ptr(iter->trace_buffer->data, iter->cpu)->skipped_entries)
 		return;
 
-	if (iter->started)
+	if (cpumask_available(iter->started))
 		cpumask_set_cpu(iter->cpu, iter->started);
 
 	/* Don't print started cpu buffer for the first entry of the trace */