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

From: David Miller
Date: Wed May 31 2017 - 14:38:20 EST


From: Jia-Ju Bai <baijiaju1990@xxxxxxx>
Date: Wed, 31 May 2017 10:43:40 +0800

> The driver may sleep under a spin lock in some function call paths.
> The 1st function call path is:
> enic_tx_hang_reset (acquire the lock by spin_lock)
> enic_stop
> enic_synchronize_irqs
> synchronize_irq --> may sleep
> The 2nd function call path is:
> enic_tx_hang_reset (acquire the lock by spin_lock)
> enic_dev_wait
> schedule_timeout_uninterruptible --> may sleep
> The 3rd function call path is:
> enic_tx_hang_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_tx_hang_reset.
>
> Signed-off-by: Jia-Ju Bai <baijiaju1990@xxxxxxx>

Likewise, you can't just blindly remove locks to fix a warning like
this.