rcuperf: Fix cleanup path for invalid perf_type strings

If the specified rcuperf.perf_type is not in the rcu_perf_init()
function's perf_ops[] array, rcuperf prints some console messages and
then invokes rcu_perf_cleanup() to set state so that a future torture
test can run.  However, rcu_perf_cleanup() also attempts to end the
test that didn't actually start, and in doing so relies on the value
of cur_ops, a value that is not particularly relevant in this case.
This can result in confusing output or even follow-on failures due to
attempts to use facilities that have not been properly initialized.

This commit therefore sets the value of cur_ops to NULL in this case and
inserts a check near the beginning of rcu_perf_cleanup(), thus avoiding
relying on an irrelevant cur_ops value.

Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>

diff --git a/kernel/rcu/rcuperf.c b/kernel/rcu/rcuperf.c
index c29761152874471bd42f696e3e320304bf7b6f91..7a6890b23c5f545134607ed8897b841b841ee3bd 100644 (file)
--- a/kernel/rcu/rcuperf.c
+++ b/kernel/rcu/rcuperf.c
@@ -494,6 +494,10 @@ rcu_perf_cleanup(void)
 
        if (torture_cleanup_begin())
                return;
+       if (!cur_ops) {
+               torture_cleanup_end();
+               return;
+       }
 
        if (reader_tasks) {
                for (i = 0; i < nrealreaders; i++)
@@ -614,6 +618,7 @@ rcu_perf_init(void)
                pr_cont("\n");
                WARN_ON(!IS_MODULE(CONFIG_RCU_PERF_TEST));
                firsterr = -EINVAL;
+               cur_ops = NULL;
                goto unwind;
        }
        if (cur_ops->init)