2014-04-14 10:41:47

by Daeseok Youn

Subject: [PATCH V2] workqueue: fix double unlock bug

mutex_unlock() and put_pwq_unlocked() do not need to be called
when alloc_unbound_pwq() is failed.

And remove "if" condition for whether "pwq" is same as "wq->dfl_pwq"
when wq_calc_node_cpumask() returns false and just use "goto use_dfl_pwq"

Signed-off-by: Daeseok Youn <[email protected]>
---
V2: replace "if condition" with "goto" as Lai's comment.

kernel/workqueue.c | 7 ++-----
1 files changed, 2 insertions(+), 5 deletions(-)

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 0ee63af..9853067 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -4087,10 +4087,7 @@ static void wq_update_unbound_numa(struct workqueue_struct *wq, int cpu,
if (cpumask_equal(cpumask, pwq->pool->attrs->cpumask))
goto out_unlock;
} else {
- if (pwq == wq->dfl_pwq)
- goto out_unlock;
- else
- goto use_dfl_pwq;
+ goto use_dfl_pwq;
}

mutex_unlock(&wq->mutex);
@@ -4100,7 +4097,7 @@ static void wq_update_unbound_numa(struct workqueue_struct *wq, int cpu,
if (!pwq) {
pr_warning("workqueue: allocation failed while updating NUMA affinity of \"%s\"\n",
wq->name);
- goto out_unlock;
+ return;
}

/*
--
1.7.4.4

2014-04-14 13:13:44

by Lai Jiangshan

Subject: Re: [PATCH V2] workqueue: fix double unlock bug

On Mon, Apr 14, 2014 at 6:41 PM, Daeseok Youn <[email protected]> wrote:
>
> mutex_unlock() and put_pwq_unlocked() do not need to be called
> when alloc_unbound_pwq() is failed.
>
> And remove "if" condition for whether "pwq" is same as "wq->dfl_pwq"
> when wq_calc_node_cpumask() returns false and just use "goto use_dfl_pwq"
>
> Signed-off-by: Daeseok Youn <[email protected]>
> ---
> V2: replace "if condition" with "goto" as Lai's comment.
>
> kernel/workqueue.c | 7 ++-----
> 1 files changed, 2 insertions(+), 5 deletions(-)
>
> diff --git a/kernel/workqueue.c b/kernel/workqueue.c
> index 0ee63af..9853067 100644
> --- a/kernel/workqueue.c
> +++ b/kernel/workqueue.c
> @@ -4087,10 +4087,7 @@ static void wq_update_unbound_numa(struct workqueue_struct *wq, int cpu,
> if (cpumask_equal(cpumask, pwq->pool->attrs->cpumask))
> goto out_unlock;
> } else {
> - if (pwq == wq->dfl_pwq)
> - goto out_unlock;
> - else
> - goto use_dfl_pwq;
> + goto use_dfl_pwq;
> }
>
> mutex_unlock(&wq->mutex);
> @@ -4100,7 +4097,7 @@ static void wq_update_unbound_numa(struct workqueue_struct *wq, int cpu,
> if (!pwq) {
> pr_warning("workqueue: allocation failed while updating NUMA affinity of \"%s\"\n",
> wq->name);
> - goto out_unlock;
> + return;

Please acquire the wq->mutex and goto use_dfl_pwq;

> }
>
> /*
> --
> 1.7.4.4
>
>
> --
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