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* [PATCH] can: fix hrtimer/tasklet termination in bcm op removal
@ 2017-01-18 20:30 Oliver Hartkopp
  2017-01-18 20:40 ` Oliver Hartkopp
  2017-01-28 16:42 ` Michael Josenhans
  0 siblings, 2 replies; 5+ messages in thread
From: Oliver Hartkopp @ 2017-01-18 20:30 UTC (permalink / raw)
  To: linux-can; +Cc: Michael Josenhans, Oliver Hartkopp

When removing a bcm tx operation either a hrtimer or a tasklet might run.
As the hrtimer triggers its associated tasklet and vice versa we need to
take care to mutually terminate both handlers.

Reported-by: Michael Josenhans <michael.josenhans@web.de>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
---
 net/can/bcm.c | 23 ++++++++++++++++-------
 1 file changed, 16 insertions(+), 7 deletions(-)

diff --git a/net/can/bcm.c b/net/can/bcm.c
index 21ac75390e3d..a7dc80c8e724 100644
--- a/net/can/bcm.c
+++ b/net/can/bcm.c
@@ -734,14 +734,23 @@ static struct bcm_op *bcm_find_op(struct list_head *ops,
 
 static void bcm_remove_op(struct bcm_op *op)
 {
-	hrtimer_cancel(&op->timer);
-	hrtimer_cancel(&op->thrtimer);
-
-	if (op->tsklet.func)
-		tasklet_kill(&op->tsklet);
+	if (op->tsklet.func) {
+		while (test_bit(TASKLET_STATE_SCHED, &op->tsklet.state) ||
+		       test_bit(TASKLET_STATE_RUN, &op->tsklet.state) ||
+		       hrtimer_active(&op->timer)) {
+			hrtimer_cancel(&op->timer);
+			tasklet_kill(&op->tsklet);
+		}
+	}
 
-	if (op->thrtsklet.func)
-		tasklet_kill(&op->thrtsklet);
+	if (op->thrtsklet.func) {
+		while (test_bit(TASKLET_STATE_SCHED, &op->thrtsklet.state) ||
+		       test_bit(TASKLET_STATE_RUN, &op->thrtsklet.state) ||
+		       hrtimer_active(&op->thrtimer)) {
+			hrtimer_cancel(&op->thrtimer);
+			tasklet_kill(&op->thrtsklet);
+		}
+	}
 
 	if ((op->frames) && (op->frames != &op->sframe))
 		kfree(op->frames);
-- 
2.11.0


^ permalink raw reply related	[flat|nested] 5+ messages in thread

* Re: [PATCH] can: fix hrtimer/tasklet termination in bcm op removal
  2017-01-18 20:30 [PATCH] can: fix hrtimer/tasklet termination in bcm op removal Oliver Hartkopp
@ 2017-01-18 20:40 ` Oliver Hartkopp
  2017-01-28 16:42 ` Michael Josenhans
  1 sibling, 0 replies; 5+ messages in thread
From: Oliver Hartkopp @ 2017-01-18 20:40 UTC (permalink / raw)
  To: Michael Josenhans; +Cc: linux-can

Hi Michael,

thanks for your bug report!

I created and tested this patch with some weird settings using a 1 usec 
cycle together with TX_SETUP and TX_DELETE.

Can you please check this patch with your setup?

Best regards,
Oliver

On 01/18/2017 09:30 PM, Oliver Hartkopp wrote:
> When removing a bcm tx operation either a hrtimer or a tasklet might run.
> As the hrtimer triggers its associated tasklet and vice versa we need to
> take care to mutually terminate both handlers.
>
> Reported-by: Michael Josenhans <michael.josenhans@web.de>
> Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
> ---
>  net/can/bcm.c | 23 ++++++++++++++++-------
>  1 file changed, 16 insertions(+), 7 deletions(-)
>
> diff --git a/net/can/bcm.c b/net/can/bcm.c
> index 21ac75390e3d..a7dc80c8e724 100644
> --- a/net/can/bcm.c
> +++ b/net/can/bcm.c
> @@ -734,14 +734,23 @@ static struct bcm_op *bcm_find_op(struct list_head *ops,
>
>  static void bcm_remove_op(struct bcm_op *op)
>  {
> -	hrtimer_cancel(&op->timer);
> -	hrtimer_cancel(&op->thrtimer);
> -
> -	if (op->tsklet.func)
> -		tasklet_kill(&op->tsklet);
> +	if (op->tsklet.func) {
> +		while (test_bit(TASKLET_STATE_SCHED, &op->tsklet.state) ||
> +		       test_bit(TASKLET_STATE_RUN, &op->tsklet.state) ||
> +		       hrtimer_active(&op->timer)) {
> +			hrtimer_cancel(&op->timer);
> +			tasklet_kill(&op->tsklet);
> +		}
> +	}
>
> -	if (op->thrtsklet.func)
> -		tasklet_kill(&op->thrtsklet);
> +	if (op->thrtsklet.func) {
> +		while (test_bit(TASKLET_STATE_SCHED, &op->thrtsklet.state) ||
> +		       test_bit(TASKLET_STATE_RUN, &op->thrtsklet.state) ||
> +		       hrtimer_active(&op->thrtimer)) {
> +			hrtimer_cancel(&op->thrtimer);
> +			tasklet_kill(&op->thrtsklet);
> +		}
> +	}
>
>  	if ((op->frames) && (op->frames != &op->sframe))
>  		kfree(op->frames);
>

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] can: fix hrtimer/tasklet termination in bcm op removal
  2017-01-18 20:30 [PATCH] can: fix hrtimer/tasklet termination in bcm op removal Oliver Hartkopp
  2017-01-18 20:40 ` Oliver Hartkopp
@ 2017-01-28 16:42 ` Michael Josenhans
  2017-01-28 17:25   ` Oliver Hartkopp
  1 sibling, 1 reply; 5+ messages in thread
From: Michael Josenhans @ 2017-01-28 16:42 UTC (permalink / raw)
  To: Oliver Hartkopp, linux-can



When removing a bcm tx operation either a hrtimer or a tasklet might run.
As the hrtimer triggers its associated tasklet and vice versa we need to
take care to mutually terminate both handlers.

Reported-by: Michael Josenhans <michael.josenhans@web.de>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Tested-by: Michael Josenhans <michael.josenhans@web.de>
> ---
>  net/can/bcm.c | 23 ++++++++++++++++-------
>  1 file changed, 16 insertions(+), 7 deletions(-)
>
> diff --git a/net/can/bcm.c b/net/can/bcm.c
> index 21ac75390e3d..a7dc80c8e724 100644
> --- a/net/can/bcm.c
> +++ b/net/can/bcm.c
> @@ -734,14 +734,23 @@ static struct bcm_op *bcm_find_op(struct list_head *ops,
>
>  static void bcm_remove_op(struct bcm_op *op)
>  {
> -	hrtimer_cancel(&op->timer);
> -	hrtimer_cancel(&op->thrtimer);
> -
> -	if (op->tsklet.func)
> -		tasklet_kill(&op->tsklet);
> +	if (op->tsklet.func) {
> +		while (test_bit(TASKLET_STATE_SCHED, &op->tsklet.state) ||
> +		       test_bit(TASKLET_STATE_RUN, &op->tsklet.state) ||
> +		       hrtimer_active(&op->timer)) {
> +			hrtimer_cancel(&op->timer);
> +			tasklet_kill(&op->tsklet);
> +		}
> +	}
>
> -	if (op->thrtsklet.func)
> -		tasklet_kill(&op->thrtsklet);
> +	if (op->thrtsklet.func) {
> +		while (test_bit(TASKLET_STATE_SCHED, &op->thrtsklet.state) ||
> +		       test_bit(TASKLET_STATE_RUN, &op->thrtsklet.state) ||
> +		       hrtimer_active(&op->thrtimer)) {
> +			hrtimer_cancel(&op->thrtimer);
> +			tasklet_kill(&op->thrtsklet);
> +		}
> +	}
>
>  	if ((op->frames) && (op->frames != &op->sframe))
>  		kfree(op->frames);
> --

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] can: fix hrtimer/tasklet termination in bcm op removal
  2017-01-28 16:42 ` Michael Josenhans
@ 2017-01-28 17:25   ` Oliver Hartkopp
  2017-01-30 10:06     ` Marc Kleine-Budde
  0 siblings, 1 reply; 5+ messages in thread
From: Oliver Hartkopp @ 2017-01-28 17:25 UTC (permalink / raw)
  To: Michael Josenhans, Marc Kleine-Budde; +Cc: linux-can

On 01/28/2017 05:42 PM, Michael Josenhans wrote:

> When removing a bcm tx operation either a hrtimer or a tasklet might run.
> As the hrtimer triggers its associated tasklet and vice versa we need to
> take care to mutually terminate both handlers.
>
> Reported-by: Michael Josenhans <michael.josenhans@web.de>
> Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
> Tested-by: Michael Josenhans <michael.josenhans@web.de>

Thanks for testing!

@Marc: This is a candidate for stable too.

Best regards,
Oliver

>> ---
>>  net/can/bcm.c | 23 ++++++++++++++++-------
>>  1 file changed, 16 insertions(+), 7 deletions(-)
>>
>> diff --git a/net/can/bcm.c b/net/can/bcm.c
>> index 21ac75390e3d..a7dc80c8e724 100644
>> --- a/net/can/bcm.c
>> +++ b/net/can/bcm.c
>> @@ -734,14 +734,23 @@ static struct bcm_op *bcm_find_op(struct
>> list_head *ops,
>>
>>  static void bcm_remove_op(struct bcm_op *op)
>>  {
>> -    hrtimer_cancel(&op->timer);
>> -    hrtimer_cancel(&op->thrtimer);
>> -
>> -    if (op->tsklet.func)
>> -        tasklet_kill(&op->tsklet);
>> +    if (op->tsklet.func) {
>> +        while (test_bit(TASKLET_STATE_SCHED, &op->tsklet.state) ||
>> +               test_bit(TASKLET_STATE_RUN, &op->tsklet.state) ||
>> +               hrtimer_active(&op->timer)) {
>> +            hrtimer_cancel(&op->timer);
>> +            tasklet_kill(&op->tsklet);
>> +        }
>> +    }
>>
>> -    if (op->thrtsklet.func)
>> -        tasklet_kill(&op->thrtsklet);
>> +    if (op->thrtsklet.func) {
>> +        while (test_bit(TASKLET_STATE_SCHED, &op->thrtsklet.state) ||
>> +               test_bit(TASKLET_STATE_RUN, &op->thrtsklet.state) ||
>> +               hrtimer_active(&op->thrtimer)) {
>> +            hrtimer_cancel(&op->thrtimer);
>> +            tasklet_kill(&op->thrtsklet);
>> +        }
>> +    }
>>
>>      if ((op->frames) && (op->frames != &op->sframe))
>>          kfree(op->frames);
>> --

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] can: fix hrtimer/tasklet termination in bcm op removal
  2017-01-28 17:25   ` Oliver Hartkopp
@ 2017-01-30 10:06     ` Marc Kleine-Budde
  0 siblings, 0 replies; 5+ messages in thread
From: Marc Kleine-Budde @ 2017-01-30 10:06 UTC (permalink / raw)
  To: Oliver Hartkopp, Michael Josenhans; +Cc: linux-can


[-- Attachment #1.1: Type: text/plain, Size: 875 bytes --]

On 01/28/2017 06:25 PM, Oliver Hartkopp wrote:
> On 01/28/2017 05:42 PM, Michael Josenhans wrote:
> 
>> When removing a bcm tx operation either a hrtimer or a tasklet might run.
>> As the hrtimer triggers its associated tasklet and vice versa we need to
>> take care to mutually terminate both handlers.
>>
>> Reported-by: Michael Josenhans <michael.josenhans@web.de>
>> Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
>> Tested-by: Michael Josenhans <michael.josenhans@web.de>
> 
> Thanks for testing!
> 
> @Marc: This is a candidate for stable too.

added to can.

Marc

-- 
Pengutronix e.K.                  | Marc Kleine-Budde           |
Industrial Linux Solutions        | Phone: +49-231-2826-924     |
Vertretung West/Dortmund          | Fax:   +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |


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^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2017-01-30 10:46 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2017-01-18 20:30 [PATCH] can: fix hrtimer/tasklet termination in bcm op removal Oliver Hartkopp
2017-01-18 20:40 ` Oliver Hartkopp
2017-01-28 16:42 ` Michael Josenhans
2017-01-28 17:25   ` Oliver Hartkopp
2017-01-30 10:06     ` Marc Kleine-Budde

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