tracing: Use cpumask_available() to check if cpumask variable may be used

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@chromium.org

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

1 files changed, 3 insertions, 2 deletions

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 4ad4420b33d6..c4536c449021 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -3311,13 +3311,14 @@ static void test_cpu_buff_start(struct trace_iterator *iter)
         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 */