* [BUG] vt6655: A possible sleep-in-atomic bug in vt6655_suspend
@ 2017-10-09 1:10 Jia-Ju Bai
2017-10-09 5:43 ` Greg KH
0 siblings, 1 reply; 3+ messages in thread
From: Jia-Ju Bai @ 2017-10-09 1:10 UTC (permalink / raw)
To: forest, gregkh, simon, tvboxspy, scott, dan.a.cashman,
golubev.mikhail, bhelgaas
Cc: devel, Linux Kernel Mailing List, linux-pci
According to device_main.c, the driver may sleep under a spinlock,
and the function call path is:
vt6655_suspend (acquire the spinlock)
pci_set_power_state
__pci_start_power_transition (drivers/pci/pci.c)
msleep --> may sleep
A possible fix is to replace msleep with mdelay in
__pci_start_power_transition in drivers/pci/pci.c.
This bug is found by my static analysis tool and my code review.
Thanks,
Jia-Ju Bai
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [BUG] vt6655: A possible sleep-in-atomic bug in vt6655_suspend
2017-10-09 1:10 [BUG] vt6655: A possible sleep-in-atomic bug in vt6655_suspend Jia-Ju Bai
@ 2017-10-09 5:43 ` Greg KH
2017-10-09 7:56 ` Jia-Ju Bai
0 siblings, 1 reply; 3+ messages in thread
From: Greg KH @ 2017-10-09 5:43 UTC (permalink / raw)
To: Jia-Ju Bai
Cc: forest, simon, tvboxspy, scott, dan.a.cashman, golubev.mikhail,
bhelgaas, devel, Linux Kernel Mailing List, linux-pci
On Mon, Oct 09, 2017 at 09:10:28AM +0800, Jia-Ju Bai wrote:
> According to device_main.c, the driver may sleep under a spinlock,
> and the function call path is:
> vt6655_suspend (acquire the spinlock)
> pci_set_power_state
> __pci_start_power_transition (drivers/pci/pci.c)
> msleep --> may sleep
>
> A possible fix is to replace msleep with mdelay in
> __pci_start_power_transition in drivers/pci/pci.c.
Patches are usually best to send in for things that you find like this.
thanks,
greg k-h
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [BUG] vt6655: A possible sleep-in-atomic bug in vt6655_suspend
2017-10-09 5:43 ` Greg KH
@ 2017-10-09 7:56 ` Jia-Ju Bai
0 siblings, 0 replies; 3+ messages in thread
From: Jia-Ju Bai @ 2017-10-09 7:56 UTC (permalink / raw)
To: Greg KH
Cc: forest, simon, tvboxspy, scott, dan.a.cashman, golubev.mikhail,
bhelgaas, devel, Linux Kernel Mailing List, linux-pci
Okay, I will send a patch :)
Thanks,
Jia-Ju Bai
On 2017/10/9 13:43, Greg KH wrote:
> On Mon, Oct 09, 2017 at 09:10:28AM +0800, Jia-Ju Bai wrote:
>> According to device_main.c, the driver may sleep under a spinlock,
>> and the function call path is:
>> vt6655_suspend (acquire the spinlock)
>> pci_set_power_state
>> __pci_start_power_transition (drivers/pci/pci.c)
>> msleep --> may sleep
>>
>> A possible fix is to replace msleep with mdelay in
>> __pci_start_power_transition in drivers/pci/pci.c.
> Patches are usually best to send in for things that you find like this.
>
> thanks,
>
> greg k-h
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2017-10-09 7:57 UTC | newest]
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2017-10-09 1:10 [BUG] vt6655: A possible sleep-in-atomic bug in vt6655_suspend Jia-Ju Bai
2017-10-09 5:43 ` Greg KH
2017-10-09 7:56 ` Jia-Ju Bai
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