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rcuscale: Do a proper cleanup if kfree_scale_init() fails

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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: 084e04fff1 ("rcuscale: Add laziness and kfree tests")
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
This commit is contained in:
Uladzislau Rezki (Sony) 2024-11-13 12:00:08 +01:00 committed by Frederic Weisbecker
parent 80e935c8c1
commit 812a1c3b9f
1 changed files with 4 additions and 2 deletions
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6
kernel/rcu/rcuscale.c
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@ -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;
}
}