[PATCH AUTOSEL 5.10 044/217] refscale: Prevent hangs for invalid arguments

Sasha Levin
2020-12-23T03:11:15Z

From: "Paul E. McKenney" <paulmck@kernel.org>

[ Upstream commit bc80d353b3f565138cda7e95ed4020e6e69360b2 ]

If an refscale torture-test run is given a bad kvm.sh argument, the
test will complain to the console, which is good. What is bad is that
from the user's perspective, it will just hang for the time specified
by the --duration argument. This commit therefore forces an immediate
kernel shutdown if a ref_scale_init()-time error occurs, thus avoiding
the appearance of a hang. It also forces a console splat in this case
to clearly indicate the presence of an error.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
kernel/rcu/refscale.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/kernel/rcu/refscale.c b/kernel/rcu/refscale.c
index 952595c678b37..8aa886684b067 100644
--- a/kernel/rcu/refscale.c
+++ b/kernel/rcu/refscale.c
@@ -658,7 +658,6 @@ ref_scale_init(void)
for (i = 0; i < ARRAY_SIZE(scale_ops); i++)
pr_cont(" %s", scale_ops[i]->name);
pr_cont("\n");
- WARN_ON(!IS_MODULE(CONFIG_RCU_REF_SCALE_TEST));
firsterr = -EINVAL;
cur_ops = NULL;
goto unwind;
@@ -712,6 +711,10 @@ ref_scale_init(void)
unwind:
torture_init_end();
ref_scale_cleanup();
+ if (shutdown) {
+ WARN_ON(!IS_MODULE(CONFIG_RCU_REF_SCALE_TEST));
+ kernel_power_off();
+ }
return firsterr;
}

--
2.27.0