Re: [PATCH] rts5208: Fix a sleep-in-atomic bug in rtsx_exclusive_enter_ss

[Jia-Ju Bai]

On 06/03/2017 04:52 PM, Greg KH wrote:
> On Thu, Jun 01, 2017 at 11:43:35AM +0800, Jia-Ju Bai wrote:
> > The driver may sleep under a spin lock, and the function call path is:
> > rtsx_exclusive_enter_ss (acquire the lock by spin_lock)
> >    rtsx_enter_ss
> >      rtsx_power_off_card
> >        sd_cleanup_work
> >          sd_stop_seq_mode
> >            sd_switch_clock
> >              sd_ddr_tuning
> >                sd_ddr_pre_tuning_tx
> >                  sd_change_phase
> >                    wait_timeout
> >                      schedule_timeout -->  may sleep
> >
> > To fix it, "wait_timeout" is replaced with mdelay in sd_change_phase.
> Nice work, how are you finding these bugs?  What tools gives you this
> kind of analysis?
>
> thanks,
>
> greg k-h
Hi,

I am very glad to get your praise on my work :)
I recently write a static analysis tool for detecting sleep-in-atomic 
bugs, instead of using existing tools. One reason is that I have 
encountered these bugs for some times when I writing drivers.
I am still improving my tool and detecting other similar bugs in Linux 
kernel. If you have suggestions or comments on my work, please feel free 
to contact me :)

Thanks,
Jia-Ju Bai