6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Uladzislau Rezki (Sony) <urezki@xxxxxxxxx>
[ Upstream commit 812a1c3b9f7c36d9255f0d29d0a3d324e2f52321 ]
A static analyzer for C, Smatch, reports and triggers below
warnings:
kernel/rcu/rcuscale.c:1215 rcu_scale_init()
warn: inconsistent returns 'global &fullstop_mutex'.
The checker complains about, we do not unlock the "fullstop_mutex"
mutex, in case of hitting below error path:
<snip>
...
if (WARN_ON_ONCE(jiffies_at_lazy_cb - jif_start < 2 * HZ)) {
pr_alert("ERROR: call_rcu() CBs are not being lazy as expected!\n");
WARN_ON_ONCE(1);
return -1;
^^^^^^^^^^
...
<snip>
it happens because "-1" is returned right away instead of
doing a proper unwinding.
Fix it by jumping to "unwind" label instead of returning -1.
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Reviewed-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
Reviewed-by: Neeraj Upadhyay <Neeraj.Upadhyay@xxxxxxx>
Closes: https://lore.kernel.org/rcu/ZxfTrHuEGtgnOYWp@pc636/T/
Fixes: 084e04fff160 ("rcuscale: Add laziness and kfree tests")
Signed-off-by: Uladzislau Rezki (Sony) <urezki@xxxxxxxxx>
Signed-off-by: Frederic Weisbecker <frederic@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
kernel/rcu/rcuscale.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/kernel/rcu/rcuscale.c b/kernel/rcu/rcuscale.c
index ed46d9e8c0e43..902575db9aec3 100644
--- a/kernel/rcu/rcuscale.c
+++ b/kernel/rcu/rcuscale.c
@@ -780,13 +780,15 @@ kfree_scale_init(void)
if (WARN_ON_ONCE(jiffies_at_lazy_cb - jif_start < 2 * HZ)) {
pr_alert("ERROR: call_rcu() CBs are not being lazy as expected!\n");
WARN_ON_ONCE(1);
- return -1;
+ firsterr = -1;
+ goto unwind;
}
if (WARN_ON_ONCE(jiffies_at_lazy_cb - jif_start > 3 * HZ)) {
pr_alert("ERROR: call_rcu() CBs are being too lazy!\n");
WARN_ON_ONCE(1);
- return -1;
+ firsterr = -1;
+ goto unwind;
}
}
--
2.43.0
