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References: <20210722030352.3966-1-thunder.leizhen@huawei.com> <20210722030352.3966-2-thunder.leizhen@huawei.com>
In-Reply-To: <20210722030352.3966-2-thunder.leizhen@huawei.com>
From:   Lai Jiangshan <jiangshanlai@gmail.com>
Date:   Wed, 28 Jul 2021 10:50:02 +0800
Message-ID: <CAJhGHyDtcxtc1NPXB7rt88vEXyVHE0c=QWDuA2UWpXeJqzCQHQ@mail.gmail.com>
Subject: Re: [PATCH v2 1/1] workqueue: Fix possible memory leaks in wq_numa_init()
To:     Zhen Lei <thunder.leizhen@huawei.com>
Cc:     Tejun Heo <tj@kernel.org>,
        linux-kernel <linux-kernel@vger.kernel.org>
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Reviewed-by: Lai Jiangshan <jiangshanlai@gmail.com>

On Thu, Jul 22, 2021 at 11:04 AM Zhen Lei <thunder.leizhen@huawei.com> wrote:
>
> In error handling branch "if (WARN_ON(node == NUMA_NO_NODE))", the
> previously allocated memories are not released. Doing this before
> allocating memory eliminates memory leaks.
>
> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
> ---
>  kernel/workqueue.c | 12 +++++++-----
>  1 file changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/kernel/workqueue.c b/kernel/workqueue.c
> index 50142fc08902..79cc470bd9ce 100644
> --- a/kernel/workqueue.c
> +++ b/kernel/workqueue.c
> @@ -5896,6 +5896,13 @@ static void __init wq_numa_init(void)
>                 return;
>         }
>
> +       for_each_possible_cpu(cpu) {
> +               if (WARN_ON(cpu_to_node(cpu) == NUMA_NO_NODE)) {
> +                       pr_warn("workqueue: NUMA node mapping not available for cpu%d, disabling NUMA support\n", cpu);
> +                       return;
> +               }
> +       }
> +
>         wq_update_unbound_numa_attrs_buf = alloc_workqueue_attrs();
>         BUG_ON(!wq_update_unbound_numa_attrs_buf);
>
> @@ -5913,11 +5920,6 @@ static void __init wq_numa_init(void)
>
>         for_each_possible_cpu(cpu) {
>                 node = cpu_to_node(cpu);
> -               if (WARN_ON(node == NUMA_NO_NODE)) {
> -                       pr_warn("workqueue: NUMA node mapping not available for cpu%d, disabling NUMA support\n", cpu);
> -                       /* happens iff arch is bonkers, let's just proceed */
> -                       return;
> -               }
>                 cpumask_set_cpu(cpu, tbl[node]);
>         }
>
> --
> 2.25.1
>