Re: [PATCH V3] workqueue: fix double unlock bug
Hi, Tejun.
2014-04-15 23:43 GMT+09:00 Tejun Heo :
> On Tue, Apr 15, 2014 at 08:17:43AM +0900, Daeseok Youn wrote:
>>
>> Use default pwq 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
>
> This is an awfully inadequate patch description. Can you change it to
> something like the following?
OK. I will change the patch description as your comment.
>
> workqueue: fix bugs in wq_update_unbound_numa() failure path
>
> wq_update_unbound_numa() failure path has the following two bugs.
>
> * alloc_unbound_pwq() is called without holding wq->mutex; however, if
> the allocation fails, it jumps to out_unlock which tries to unlock
> wq->mutex.
>
> * The function should switch to dfl_pwq on failure but didn't do so
> after alloc_unbound_pwq() failure.
>
> Fix it by regrabbing wq->mutex and jumping to use_dfl_pwq on
> alloc_unbound_pwq() failure.
>
>
>> diff --git a/kernel/workqueue.c b/kernel/workqueue.c
>> index 0ee63af..0679854 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;
>
> And please put this in a separate patch. Patches which are to be
> backported through -stable should be minimal. Also, please update the
> comment above to reflect the change.
Yes, I will do.
Thanks for review.
Regards,
Daeseok Youn.
>
> Thanks.
>
> --
> tejun
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Re: [PATCH V3] workqueue: fix double unlock bug
On Tue, Apr 15, 2014 at 08:17:43AM +0900, Daeseok Youn wrote:
>
> Use default pwq 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
This is an awfully inadequate patch description. Can you change it to
something like the following?
workqueue: fix bugs in wq_update_unbound_numa() failure path
wq_update_unbound_numa() failure path has the following two bugs.
* alloc_unbound_pwq() is called without holding wq->mutex; however, if
the allocation fails, it jumps to out_unlock which tries to unlock
wq->mutex.
* The function should switch to dfl_pwq on failure but didn't do so
after alloc_unbound_pwq() failure.
Fix it by regrabbing wq->mutex and jumping to use_dfl_pwq on
alloc_unbound_pwq() failure.
> diff --git a/kernel/workqueue.c b/kernel/workqueue.c
> index 0ee63af..0679854 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;
And please put this in a separate patch. Patches which are to be
backported through -stable should be minimal. Also, please update the
comment above to reflect the change.
Thanks.
--
tejun
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Re: [PATCH V3] workqueue: fix double unlock bug
Hi, Tejun
Acked-by: Lai Jiangshan
CC: sta...@kernel.org
Thanks,
Lai
On 04/15/2014 07:17 AM, Daeseok Youn wrote:
>
> Use default pwq 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
> ---
> V2: replace "if condition" with "goto" as Lai's comment.
> V3: Use default pwq when alloc_unbound_pwq() is failed.
>
> kernel/workqueue.c |8 +++-
> 1 files changed, 3 insertions(+), 5 deletions(-)
>
> diff --git a/kernel/workqueue.c b/kernel/workqueue.c
> index 0ee63af..0679854 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 +4097,8 @@ 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;
> + mutex_lock(&wq->mutex);
> + goto use_dfl_pwq;
> }
>
> /*
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[PATCH V3] workqueue: fix double unlock bug
Use default pwq 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
---
V2: replace "if condition" with "goto" as Lai's comment.
V3: Use default pwq when alloc_unbound_pwq() is failed.
kernel/workqueue.c |8 +++-
1 files changed, 3 insertions(+), 5 deletions(-)
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 0ee63af..0679854 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 +4097,8 @@ 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;
+ mutex_lock(&wq->mutex);
+ goto use_dfl_pwq;
}
/*
--
1.7.4.4
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