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* RE: [PATCH v2] USB: usbtmc: Fix RCU stall warning
@ 2021-07-23  8:39 Guido Kiener
  2021-07-27 13:52 ` gregkh
  0 siblings, 1 reply; 5+ messages in thread
From: Guido Kiener @ 2021-07-23  8:39 UTC (permalink / raw)
  To: qiang.zhang, stern, gregkh, dave penkler (dpenkler@gmail.com); +Cc: linux-usb

> From: Qiang.zhang> 
> rcu: INFO: rcu_preempt self-detected stall on CPU
> rcu:    1-...!: (2 ticks this GP) idle=d92/1/0x4000000000000000
>         softirq=25390/25392 fqs=3
>         (t=12164 jiffies g=31645 q=43226)
> rcu: rcu_preempt kthread starved for 12162 jiffies! g31645 f0x0
>      RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
> rcu:    Unless rcu_preempt kthread gets sufficient CPU time,
>         OOM is now expected behavior.
> rcu: RCU grace-period kthread stack dump:
> task:rcu_preempt     state:R  running task
> ...........
> usbtmc 3-1:0.0: unknown status received: -71 usbtmc 3-1:0.0: unknown status
> received: -71 usbtmc 3-1:0.0: unknown status received: -71 usbtmc 3-1:0.0:
> unknown status received: -71 usbtmc 3-1:0.0: unknown status received: -71 usbtmc
> 3-1:0.0: unknown status received: -71 usbtmc 3-1:0.0: unknown status received: -71
> usbtmc 3-1:0.0: unknown status received: -71 usbtmc 3-1:0.0: usb_submit_urb
> failed: -19
> 
> The function usbtmc_interrupt() resubmits urbs when the error status of an urb is -
> EPROTO. In systems using the dummy_hcd usb controller this can result in endless
> interrupt loops when the usbtmc device is disconnected from the host system.
> 
> Since host controller drivers already try to recover from transmission errors, there is
> no need to resubmit the urb or try other solutions to repair the error situation.
> 
> In case of errors the INT pipe just stops to wait for further packets.
> 
> Fixes: dbf3e7f654c0 ("Implement an ioctl to support the USMTMC-USB488
> READ_STATUS_BYTE operation")
> Cc: stable@vger.kernel.org
> Reported-by: syzbot+e2eae5639e7203360018@syzkaller.appspotmail.com
> Signed-off-by: Qiang.zhang <qiang.zhang@windriver.com>
> ---
>  v1->v2:
>  Add fixes and stable tags, modify description information.
> 
>  drivers/usb/class/usbtmc.c | 9 +--------
>  1 file changed, 1 insertion(+), 8 deletions(-)
> 
> diff --git a/drivers/usb/class/usbtmc.c b/drivers/usb/class/usbtmc.c index
> 74d5a9c5238a..73f419adce61 100644
> --- a/drivers/usb/class/usbtmc.c
> +++ b/drivers/usb/class/usbtmc.c
> @@ -2324,17 +2324,10 @@ static void usbtmc_interrupt(struct urb *urb)
>  		dev_err(dev, "overflow with length %d, actual length is %d\n",
>  			data->iin_wMaxPacketSize, urb->actual_length);
>  		fallthrough;
> -	case -ECONNRESET:
> -	case -ENOENT:
> -	case -ESHUTDOWN:
> -	case -EILSEQ:
> -	case -ETIME:
> -	case -EPIPE:
> +	default:
>  		/* urb terminated, clean up */
>  		dev_dbg(dev, "urb terminated, status: %d\n", status);
>  		return;
> -	default:
> -		dev_err(dev, "unknown status received: %d\n", status);
>  	}
>  exit:
>  	rv = usb_submit_urb(urb, GFP_ATOMIC);
> --
> 2.25.1

The patch looks good to me and is tested on my machine.

Ack-by: Guido Kiener <guido.kiener@rohde-schwarz.com>

-Guido 

^ permalink raw reply	[flat|nested] 5+ messages in thread
* RE: [PATCH v2] USB: usbtmc: Fix RCU stall warning
@ 2021-07-27  7:56 Guido Kiener
  2021-07-27  9:12 ` gregkh
  0 siblings, 1 reply; 5+ messages in thread
From: Guido Kiener @ 2021-07-27  7:56 UTC (permalink / raw)
  To: qiang.zhang, stern, gregkh, dave penkler (dpenkler@gmail.com); +Cc: linux-usb

> > From: Qiang.zhang>
> > rcu: INFO: rcu_preempt self-detected stall on CPU
> > rcu:    1-...!: (2 ticks this GP) idle=d92/1/0x4000000000000000
> >         softirq=25390/25392 fqs=3
> >         (t=12164 jiffies g=31645 q=43226)
> > rcu: rcu_preempt kthread starved for 12162 jiffies! g31645 f0x0
> >      RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
> > rcu:    Unless rcu_preempt kthread gets sufficient CPU time,
> >         OOM is now expected behavior.
> > rcu: RCU grace-period kthread stack dump:
> > task:rcu_preempt     state:R  running task
> > ...........
> > usbtmc 3-1:0.0: unknown status received: -71 usbtmc 3-1:0.0: unknown
> > status
> > received: -71 usbtmc 3-1:0.0: unknown status received: -71 usbtmc 3-1:0.0:
> > unknown status received: -71 usbtmc 3-1:0.0: unknown status received:
> > -71 usbtmc
> > 3-1:0.0: unknown status received: -71 usbtmc 3-1:0.0: unknown status
> > received: -71 usbtmc 3-1:0.0: unknown status received: -71 usbtmc
> > 3-1:0.0: usb_submit_urb
> > failed: -19
> >
> > The function usbtmc_interrupt() resubmits urbs when the error status
> > of an urb is - EPROTO. In systems using the dummy_hcd usb controller
> > this can result in endless interrupt loops when the usbtmc device is disconnected
> from the host system.
> >
> > Since host controller drivers already try to recover from transmission
> > errors, there is no need to resubmit the urb or try other solutions to repair the error
> situation.
> >
> > In case of errors the INT pipe just stops to wait for further packets.
> >
> > Fixes: dbf3e7f654c0 ("Implement an ioctl to support the USMTMC-USB488
> > READ_STATUS_BYTE operation")
> > Cc: stable@vger.kernel.org
> > Reported-by: syzbot+e2eae5639e7203360018@syzkaller.appspotmail.com
> > Signed-off-by: Qiang.zhang <qiang.zhang@windriver.com>
> > ---
> >  v1->v2:
> >  Add fixes and stable tags, modify description information.
> >
> >  drivers/usb/class/usbtmc.c | 9 +--------
> >  1 file changed, 1 insertion(+), 8 deletions(-)
> >
> > diff --git a/drivers/usb/class/usbtmc.c b/drivers/usb/class/usbtmc.c
> > index
> > 74d5a9c5238a..73f419adce61 100644
> > --- a/drivers/usb/class/usbtmc.c
> > +++ b/drivers/usb/class/usbtmc.c
> > @@ -2324,17 +2324,10 @@ static void usbtmc_interrupt(struct urb *urb)
> >  		dev_err(dev, "overflow with length %d, actual length is %d\n",
> >  			data->iin_wMaxPacketSize, urb->actual_length);
> >  		fallthrough;
> > -	case -ECONNRESET:
> > -	case -ENOENT:
> > -	case -ESHUTDOWN:
> > -	case -EILSEQ:
> > -	case -ETIME:
> > -	case -EPIPE:
> > +	default:
> >  		/* urb terminated, clean up */
> >  		dev_dbg(dev, "urb terminated, status: %d\n", status);
> >  		return;
> > -	default:
> > -		dev_err(dev, "unknown status received: %d\n", status);
> >  	}
> >  exit:
> >  	rv = usb_submit_urb(urb, GFP_ATOMIC);
> > --
> > 2.25.1
> 
> The patch looks good to me and is tested on my machine.
> 
> Ack-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
> 
> -Guido

Greg,

Can you please add the patch https://patchwork.kernel.org/project/linux-usb/list/?series=520033
Dave, Alan, and I are ok with the patch.

-Guido

^ permalink raw reply	[flat|nested] 5+ messages in thread
* [PATCH v2] USB: usbtmc: Fix RCU stall warning
@ 2021-07-23  0:43 qiang.zhang
  0 siblings, 0 replies; 5+ messages in thread
From: qiang.zhang @ 2021-07-23  0:43 UTC (permalink / raw)
  To: guido.kiener, stern, gregkh; +Cc: linux-usb

From: Qiang.zhang <qiang.zhang@windriver.com>

rcu: INFO: rcu_preempt self-detected stall on CPU
rcu:    1-...!: (2 ticks this GP) idle=d92/1/0x4000000000000000
        softirq=25390/25392 fqs=3
        (t=12164 jiffies g=31645 q=43226)
rcu: rcu_preempt kthread starved for 12162 jiffies! g31645 f0x0
     RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu:    Unless rcu_preempt kthread gets sufficient CPU time,
        OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R  running task
...........
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: usb_submit_urb failed: -19

The function usbtmc_interrupt() resubmits urbs when the error status
of an urb is -EPROTO. In systems using the dummy_hcd usb controller
this can result in endless interrupt loops when the usbtmc device is
disconnected from the host system.

Since host controller drivers already try to recover from transmission
errors, there is no need to resubmit the urb or try other solutions
to repair the error situation.

In case of errors the INT pipe just stops to wait for further packets.

Fixes: dbf3e7f654c0 ("Implement an ioctl to support the USMTMC-USB488 READ_STATUS_BYTE operation")
Cc: stable@vger.kernel.org
Reported-by: syzbot+e2eae5639e7203360018@syzkaller.appspotmail.com
Signed-off-by: Qiang.zhang <qiang.zhang@windriver.com>
---
 v1->v2:
 Add fixes and stable tags, modify description information.  

 drivers/usb/class/usbtmc.c | 9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/drivers/usb/class/usbtmc.c b/drivers/usb/class/usbtmc.c
index 74d5a9c5238a..73f419adce61 100644
--- a/drivers/usb/class/usbtmc.c
+++ b/drivers/usb/class/usbtmc.c
@@ -2324,17 +2324,10 @@ static void usbtmc_interrupt(struct urb *urb)
 		dev_err(dev, "overflow with length %d, actual length is %d\n",
 			data->iin_wMaxPacketSize, urb->actual_length);
 		fallthrough;
-	case -ECONNRESET:
-	case -ENOENT:
-	case -ESHUTDOWN:
-	case -EILSEQ:
-	case -ETIME:
-	case -EPIPE:
+	default:
 		/* urb terminated, clean up */
 		dev_dbg(dev, "urb terminated, status: %d\n", status);
 		return;
-	default:
-		dev_err(dev, "unknown status received: %d\n", status);
 	}
 exit:
 	rv = usb_submit_urb(urb, GFP_ATOMIC);
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 5+ messages in thread
end of thread, other threads:[~2021-07-27 13:52 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
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2021-07-23  8:39 [PATCH v2] USB: usbtmc: Fix RCU stall warning Guido Kiener
2021-07-27 13:52 ` gregkh
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2021-07-27  7:56 Guido Kiener
2021-07-27  9:12 ` gregkh
2021-07-23  0:43 qiang.zhang

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