* [PATCH] rts5208: Fix a sleep-in-atomic bug in rtsx_exclusive_enter_ss
@ 2017-06-01 3:43 Jia-Ju Bai
2017-06-03 8:52 ` Greg KH
0 siblings, 1 reply; 3+ messages in thread
From: Jia-Ju Bai @ 2017-06-01 3:43 UTC (permalink / raw)
To: gregkh, wporter82, sergio.paracuellos, aquannie
Cc: devel, linux-kernel, Jia-Ju Bai
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.
Signed-off-by: Jia-Ju Bai <baijiaju1990@163.com>
---
drivers/staging/rts5208/sd.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/staging/rts5208/sd.c b/drivers/staging/rts5208/sd.c
index bdd35b6..76bd105 100644
--- a/drivers/staging/rts5208/sd.c
+++ b/drivers/staging/rts5208/sd.c
@@ -1057,7 +1057,7 @@ static int sd_change_phase(struct rtsx_chip *chip, u8 sample_point, u8 tune_dir)
rtsx_write_register(chip, SD_DCMPS_CTL, DCMPS_CHANGE, 0);
rtsx_write_register(chip, SD_VP_CTL, PHASE_CHANGE, 0);
- wait_timeout(10);
+ mdelay(10);
sd_reset_dcm(chip, tune_dir);
return STATUS_FAIL;
}
--
1.7.9.5
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] rts5208: Fix a sleep-in-atomic bug in rtsx_exclusive_enter_ss
2017-06-01 3:43 [PATCH] rts5208: Fix a sleep-in-atomic bug in rtsx_exclusive_enter_ss Jia-Ju Bai
@ 2017-06-03 8:52 ` Greg KH
2017-06-05 1:05 ` Jia-Ju Bai
0 siblings, 1 reply; 3+ messages in thread
From: Greg KH @ 2017-06-03 8:52 UTC (permalink / raw)
To: Jia-Ju Bai; +Cc: wporter82, sergio.paracuellos, aquannie, devel, linux-kernel
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
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] rts5208: Fix a sleep-in-atomic bug in rtsx_exclusive_enter_ss
2017-06-03 8:52 ` Greg KH
@ 2017-06-05 1:05 ` Jia-Ju Bai
0 siblings, 0 replies; 3+ messages in thread
From: Jia-Ju Bai @ 2017-06-05 1:05 UTC (permalink / raw)
To: Greg KH; +Cc: wporter82, sergio.paracuellos, aquannie, devel, linux-kernel
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
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2017-06-05 1:05 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-06-01 3:43 [PATCH] rts5208: Fix a sleep-in-atomic bug in rtsx_exclusive_enter_ss Jia-Ju Bai
2017-06-03 8:52 ` Greg KH
2017-06-05 1:05 ` Jia-Ju Bai
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).