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

[David Miller]

From: Jia-Ju Bai <baijiaju1990@xxxxxxx>
Date: Wed, 31 May 2017 10:34:49 +0800

> The driver may sleep under a spin lock in some function call paths.
> The 1st function call path is:
> enic_reset (acquire the lock by spin_lock)
>   enic_stop
>     enic_synchronize_irqs
>       synchronize_irq --> may sleep
> The 2nd function call path is:
> enic_reset (acquire the lock by spin_lock)
>   enic_dev_soft_reset
>     enic_dev_wait
>       schedule_timeout_uninterruptible --> may sleep
> The 3rd function call path is:
> enic_reset (acquire the lock by spin_lock)
>   enic_open
>     enic_request_intr
>       enic_set_rx_cpu_rmap
>         enic_free_rx_cpu_rmap
>           free_irq_cpu_rmap --> may sleep
> 
> To fix it, the "spin_lock" and "spin_unlock" are removed in enic_reset.
> 
> Signed-off-by: Jia-Ju Bai <baijiaju1990@xxxxxxx>

That's not necessarily safe at all, the lock is probably needed for
synchronization.