[PATCH 2/2] rcutorture: Add missing return and use __func__ in warning

From: David Vernet
Date: Mon Mar 07 2022 - 17:47:56 EST


The rcutorture module has an rcu_torture_writer task that repeatedly
performs writes, synchronizations, and deletes. There is a corner-case
check in rcu_torture_writer() wherein if nsynctypes is 0, a warning is
issued and the task waits to be stopped via a call to
torture_kthread_stopping() rather than performing any work.

There should be a return statement following this call to
torture_kthread_stopping(), as the intention with issuing the call to
torture_kthread_stopping() in the first place is to avoid the
rcu_torture_writer task from performing any work. Some of the work may even
be dangerous to perform, such as potentially causing a #DE due to
nsynctypes being used in a modulo operator when querying for sync updates
to issue.

This patch adds the missing return call. As a bonus, it also fixes a
checkpatch warning that was emitted due to the WARN_ONCE() call using the
name of the function rather than __func__.

Signed-off-by: David Vernet <void@xxxxxxxxxxxxx>
---
kernel/rcu/rcutorture.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 7fdff1bfed79..7d9489cdd7f2 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -1210,7 +1210,7 @@ rcu_torture_writer(void *arg)
" GP expediting controlled from boot/sysfs for %s.\n",
torture_type, cur_ops->name);
if (WARN_ONCE(nsynctypes == 0,
- "rcu_torture_writer: No update-side primitives.\n")) {
+ "%s: No update-side primitives.\n", __func__)) {
/*
* No updates primitives, so don't try updating.
* The resulting test won't be testing much, hence the
@@ -1218,6 +1218,7 @@ rcu_torture_writer(void *arg)
*/
rcu_torture_writer_state = RTWS_STOPPING;
torture_kthread_stopping("rcu_torture_writer");
+ return 0;
}

do {
--
2.30.2