6.6-stable review patch. If anyone has any objections, please let me know.
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From: Uladzislau Rezki (Sony) urezki@gmail.com
[ 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@linaro.org Reviewed-by: Paul E. McKenney paulmck@kernel.org Reviewed-by: Neeraj Upadhyay Neeraj.Upadhyay@amd.com Closes: https://lore.kernel.org/rcu/ZxfTrHuEGtgnOYWp@pc636/T/ Fixes: 084e04fff160 ("rcuscale: Add laziness and kfree tests") Signed-off-by: Uladzislau Rezki (Sony) urezki@gmail.com Signed-off-by: Frederic Weisbecker frederic@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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; } }