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