Re: [PATCH] ubifs: Fix a sleep-in-atomic bug in ubifs_read_nnode

[Jia-Ju Bai]

On 06/05/2017 04:25 PM, Richard Weinberger wrote:
> Jia-Ju Bai,
>
> Am 05.06.2017 um 05:38 schrieb Jia-Ju Bai:
> > The driver may sleep under a spin lock, and the function call path is:
> > ubifs_change_lp (acquire the lock by spin_lock)
> >    change_category
> >      ubifs_remove_from_cat
> >        remove_from_lpt_heap
> >          dbg_check_heap
> >            ubifs_lpt_lookup
> >              ubifs_read_nnode
> >                kzalloc(GFP_NOFS) -->  may sleep
> >
> > To fix it, "GFP_NOFS" is replaced with "GFP_ATOMIC".
> So, this happens only when dbg_check_heap() is activated, right?
>
> Thanks,
> //richard
Yes, I think so.

Thanks,
Jia-Ju Bai