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Sender: Tejun Heo <htejun@gmail.com>
Date:   Wed, 15 Nov 2023 16:58:34 -1000
From:   Tejun Heo <tj@kernel.org>
To:     huangzaiyang <huangzaiyang@oppo.com>
Cc:     jiangshanlai@gmail.com, linux-kernel@vger.kernel.org,
        ZaiYang Huang <hzy0719@163.com>
Subject: Re: [PATCH] workqueue: Make a warning when a pending delay work
 being re-init
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References: <20231115113427.1420-1-huangzaiyang@oppo.com>
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Hello,

On Wed, Nov 15, 2023 at 07:34:27PM +0800, huangzaiyang wrote:
> @@ -310,6 +326,7 @@ static inline unsigned int work_static(struct work_struct *work) { return 0; }
> 
>  #define __INIT_DELAYED_WORK(_work, _func, _tflags)                     \
>         do {                                                            \
> +               WARN_ON(delayed_work_pending(_work));                   \
>                 INIT_WORK(&(_work)->work, (_func));                     \
>                 __init_timer(&(_work)->timer,                           \
>                              delayed_work_timer_fn,                     \

As pointed out by others, as we don't know what's in the memory, this
wouldn't really work. This kind of bugs should be caught by
DEBUG_OBJECTS_WORK / DEBUG_OBJECTS_TIMERS, I think. It's not perfect as
those aren't usually turned on but catching this sort of errors does need
tracking some information out of band.

Thanks.

-- 
tejun