releases/4.4.181/rcutorture-fix-cleanup-path-for-invalid-torture_type.patch

   1 From 934b974e4b3d1245ba60db9061e98da902eb8291 Mon Sep 17 00:00:00 2001
   2 From: "Paul E. McKenney" <paulmck@linux.ibm.com>
   3 Date: Thu, 21 Mar 2019 09:27:28 -0700
   4 Subject: rcutorture: Fix cleanup path for invalid torture_type strings
   5
   6 [ Upstream commit b813afae7ab6a5e91b4e16cc567331d9c2ae1f04 ]
   7
   8 If the specified rcutorture.torture_type is not in the rcu_torture_init()
   9 function's torture_ops[] array, rcutorture prints some console messages
  10 and then invokes rcu_torture_cleanup() to set state so that a future
  11 torture test can run.  However, rcu_torture_cleanup() also attempts to
  12 end the test that didn't actually start, and in doing so relies on the
  13 value of cur_ops, a value that is not particularly relevant in this case.
  14 This can result in confusing output or even follow-on failures due to
  15 attempts to use facilities that have not been properly initialized.
  16
  17 This commit therefore sets the value of cur_ops to NULL in this case
  18 and inserts a check near the beginning of rcu_torture_cleanup(),
  19 thus avoiding relying on an irrelevant cur_ops value.
  20
  21 Reported-by: kernel test robot <rong.a.chen@intel.com>
  22 Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
  23 Signed-off-by: Sasha Levin <sashal@kernel.org>
  24 ---
  25  kernel/rcu/rcutorture.c | 5 +++++
  26  1 file changed, 5 insertions(+)
  27
  28 diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
  29 index d89328e260df6..041a02b334d73 100644
  30 --- a/kernel/rcu/rcutorture.c
  31 +++ b/kernel/rcu/rcutorture.c
  32 @@ -1603,6 +1603,10 @@ rcu_torture_cleanup(void)
  33                         cur_ops->cb_barrier();
  34                 return;
  35         }
  36 +       if (!cur_ops) {
  37 +               torture_cleanup_end();
  38 +               return;
  39 +       }
  40
  41         rcu_torture_barrier_cleanup();
  42         torture_stop_kthread(rcu_torture_stall, stall_task);
  43 @@ -1741,6 +1745,7 @@ rcu_torture_init(void)
  44                         pr_alert(" %s", torture_ops[i]->name);
  45                 pr_alert("\n");
  46                 firsterr = -EINVAL;
  47 +               cur_ops = NULL;
  48                 goto unwind;
  49         }
  50         if (cur_ops->fqs == NULL && fqs_duration != 0) {
  51 --
  52 2.20.1
  53