From 812a1c3b9f7c36d9255f0d29d0a3d324e2f52321 Mon Sep 17 00:00:00 2001 From: "Uladzislau Rezki (Sony)" Date: Wed, 13 Nov 2024 12:00:08 +0100 Subject: [PATCH] rcuscale: Do a proper cleanup if kfree_scale_init() fails 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: ... 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; ^^^^^^^^^^ ... 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 Reviewed-by: Paul E. McKenney Reviewed-by: Neeraj Upadhyay Closes: https://lore.kernel.org/rcu/ZxfTrHuEGtgnOYWp@pc636/T/ Fixes: 084e04fff160 ("rcuscale: Add laziness and kfree tests") Signed-off-by: Uladzislau Rezki (Sony) Signed-off-by: Frederic Weisbecker --- 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 6d37596deb1f..d360fa44b234 100644 --- a/kernel/rcu/rcuscale.c +++ b/kernel/rcu/rcuscale.c @@ -890,13 +890,15 @@ 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; } }