Re: [syzbot] WARNING in __init_work

[Thomas Gleixner]

Stephen,

On Tue, Sep 21 2021 at 11:38, Stephen Boyd wrote:
> Quoting Thomas Gleixner (2021-09-19 05:41:18)
>> Even if debug objects would support objects on irq stacks, the above is
>> still bogus. But it does not and will not because the operations here
>> have to be fully synchronous:
>> 
>>     init() -> queue() or arm() -> wait() -> destroy()
>> 
>> because you obviously cannot queue work or arm a timer which are on stack
>> and then leave the function without waiting for the operation to complete.
>
> Is there some way to make it more obvious that initializing a timer or
> work on the stack in an irq context is a NONO because we can't wait for
> it? Maybe some sort of debugobjects call to might_sleep() when it's
> being told the object is on the stack, or throwing a might_sleep() into
> the initialization of any stack based timer or workqueue, or both?

Let me have a look.