Re: [BUG] drivers/gpio: some possible sleep-in-atomic bugs

[Andreas Larsson]

On 2017-12-12 04:59, Jia-Ju Bai wrote:

According to drivers/gpio/gpio-grgpio.c, the kernel module may sleep
under a spinlock.
The function call paths are:
grgpio_remove (acquire the spinlock)
   gpiochip_remove
     gpiochip_sysfs_unregister
       device_unregister --> may sleep
       mutex_lock --> may sleep

grgpio_remove (acquire the spinlock)
   gpiochip_remove
     gpiochip_sysfs_unregister
       gpiod_free
         __gpiod_free
           gpiod_unexport
             device_unregister --> may sleep
             mutex_lock --> may sleep

grgpio_remove (acquire the spinlock)
   irq_domain_remove
     mutex_lock --> may sleep

grgpio_irq_map (acquire the spinlock)
   request_irq --> may sleep

grgpio_irq_unmap (acquire the spinlock)
   free_irq --> may sleep


I do not find a good way to fix them, so I only report.
These possible bugs is found by my static analysis tool (DSAC) and
checked by my code review.

Hi!

Thank you for reporting this. I will take a look at it.

--
Best Regards,
Andreas Larsson