In ish_probe, it calls ish_dev_init to init the device. In this function,
ishtp_device_init is called and &dev->bh_hbm_work is bound with
bh_hbm_work_fn. recv_hbm may be called to start the timer work.
If we remove the module which will call ish_remove to make cleanup,
there may be an unfinished work. The possible sequence is as follows:
Fix it by canceling the work before cleanup in ishtp_bus_remove_all_clients
CPU0 CPUc1
|bh_hbm_work_fn
ish_remove |
ishtp_bus_remove_all_clients |
kfree(ishtp_dev->fw_clients); |
|
|&dev->fw_clients[...]
| //use
Fixes: 3703f53b99e4 ("HID: intel_ish-hid: ISH Transport layer")
Signed-off-by: Zheng Wang <[email protected]>
---
drivers/hid/intel-ish-hid/ishtp/bus.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/hid/intel-ish-hid/ishtp/bus.c b/drivers/hid/intel-ish-hid/ishtp/bus.c
index 81385ab37fa9..ada7cd08dbeb 100644
--- a/drivers/hid/intel-ish-hid/ishtp/bus.c
+++ b/drivers/hid/intel-ish-hid/ishtp/bus.c
@@ -744,6 +744,7 @@ void ishtp_bus_remove_all_clients(struct ishtp_device *ishtp_dev,
*/
}
spin_unlock_irqrestore(&ishtp_dev->cl_list_lock, flags);
+ cancel_work_sync(&ishtp_dev->bh_hbm_work);
/* Release DMA buffers for client messages */
ishtp_cl_free_dma_buf(ishtp_dev);
--
2.25.1
Hi,
I missed some detail in the patch. bh_hbm_work_fn will call
ishtp_hbm_dispatch and access &dev->fw_clients in it.
Best regards,
Zheng
Zheng Wang <[email protected]> 于2023年4月13日周四 01:17写道：
>
> In ish_probe, it calls ish_dev_init to init the device. In this function,
> ishtp_device_init is called and &dev->bh_hbm_work is bound with
> bh_hbm_work_fn. recv_hbm may be called to start the timer work.
>
> If we remove the module which will call ish_remove to make cleanup,
> there may be an unfinished work. The possible sequence is as follows:
>
> Fix it by canceling the work before cleanup in ishtp_bus_remove_all_clients
>
> CPU0 CPUc1
>
> |bh_hbm_work_fn
> ish_remove |
> ishtp_bus_remove_all_clients |
> kfree(ishtp_dev->fw_clients); |
> |
> |&dev->fw_clients[...]
> | //use
>
> Fixes: 3703f53b99e4 ("HID: intel_ish-hid: ISH Transport layer")
> Signed-off-by: Zheng Wang <[email protected]>
> ---
> drivers/hid/intel-ish-hid/ishtp/bus.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/hid/intel-ish-hid/ishtp/bus.c b/drivers/hid/intel-ish-hid/ishtp/bus.c
> index 81385ab37fa9..ada7cd08dbeb 100644
> --- a/drivers/hid/intel-ish-hid/ishtp/bus.c
> +++ b/drivers/hid/intel-ish-hid/ishtp/bus.c
> @@ -744,6 +744,7 @@ void ishtp_bus_remove_all_clients(struct ishtp_device *ishtp_dev,
> */
> }
> spin_unlock_irqrestore(&ishtp_dev->cl_list_lock, flags);
> + cancel_work_sync(&ishtp_dev->bh_hbm_work);
>
> /* Release DMA buffers for client messages */
> ishtp_cl_free_dma_buf(ishtp_dev);
> --
> 2.25.1
>
On Thu, 2023-04-13 at 01:14 +0800, Zheng Wang wrote:
> In ish_probe, it calls ish_dev_init to init the device. In this
> function,
> ishtp_device_init is called and &dev->bh_hbm_work is bound with
> bh_hbm_work_fn. recv_hbm may be called to start the timer work.
>
> If we remove the module which will call ish_remove to make cleanup,
> there may be an unfinished work. The possible sequence is as follows:
>
> Fix it by canceling the work before cleanup in
> ishtp_bus_remove_all_clients
>
> CPU0 CPUc1
>
> |bh_hbm_work_fn
> ish_remove |
> ishtp_bus_remove_all_clients |
> kfree(ishtp_dev->fw_clients); |
> |
> |&dev->fw_clients[...]
> | //use
>
> Fixes: 3703f53b99e4 ("HID: intel_ish-hid: ISH Transport layer")
> Signed-off-by: Zheng Wang <[email protected]>
Acked-by: Srinivas Pandruvada <[email protected]>
It is a extremely rare case, so it is OK to not mark for stable.
> ---
> drivers/hid/intel-ish-hid/ishtp/bus.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/hid/intel-ish-hid/ishtp/bus.c
> b/drivers/hid/intel-ish-hid/ishtp/bus.c
> index 81385ab37fa9..ada7cd08dbeb 100644
> --- a/drivers/hid/intel-ish-hid/ishtp/bus.c
> +++ b/drivers/hid/intel-ish-hid/ishtp/bus.c
> @@ -744,6 +744,7 @@ void ishtp_bus_remove_all_clients(struct
> ishtp_device *ishtp_dev,
> */
> }
> spin_unlock_irqrestore(&ishtp_dev->cl_list_lock, flags);
> + cancel_work_sync(&ishtp_dev->bh_hbm_work);
>
> /* Release DMA buffers for client messages */
> ishtp_cl_free_dma_buf(ishtp_dev);
srinivas pandruvada <[email protected]> 于2023年4月25日周二 23:55写道：
>
> On Thu, 2023-04-13 at 01:14 +0800, Zheng Wang wrote:
> > In ish_probe, it calls ish_dev_init to init the device. In this
> > function,
> > ishtp_device_init is called and &dev->bh_hbm_work is bound with
> > bh_hbm_work_fn. recv_hbm may be called to start the timer work.
> >
> > If we remove the module which will call ish_remove to make cleanup,
> > there may be an unfinished work. The possible sequence is as follows:
> >
> > Fix it by canceling the work before cleanup in
> > ishtp_bus_remove_all_clients
> >
> > CPU0 CPUc1
> >
> > |bh_hbm_work_fn
> > ish_remove |
> > ishtp_bus_remove_all_clients |
> > kfree(ishtp_dev->fw_clients); |
> > |
> > |&dev->fw_clients[...]
> > | //use
> >
> > Fixes: 3703f53b99e4 ("HID: intel_ish-hid: ISH Transport layer")
> > Signed-off-by: Zheng Wang <[email protected]>
> Acked-by: Srinivas Pandruvada <[email protected]>
>
> It is a extremely rare case, so it is OK to not mark for stable.
Got it, thanks!
Best regards,
Zheng
>
> > ---
> > drivers/hid/intel-ish-hid/ishtp/bus.c | 1 +
> > 1 file changed, 1 insertion(+)
> >
> > diff --git a/drivers/hid/intel-ish-hid/ishtp/bus.c
> > b/drivers/hid/intel-ish-hid/ishtp/bus.c
> > index 81385ab37fa9..ada7cd08dbeb 100644
> > --- a/drivers/hid/intel-ish-hid/ishtp/bus.c
> > +++ b/drivers/hid/intel-ish-hid/ishtp/bus.c
> > @@ -744,6 +744,7 @@ void ishtp_bus_remove_all_clients(struct
> > ishtp_device *ishtp_dev,
> > */
> > }
> > spin_unlock_irqrestore(&ishtp_dev->cl_list_lock, flags);
> > + cancel_work_sync(&ishtp_dev->bh_hbm_work);
> >
> > /* Release DMA buffers for client messages */
> > ishtp_cl_free_dma_buf(ishtp_dev);
>