Re: [PATCH] selftests: add sleep between detach and usbip list -l

[Greg KH <greg@kroah.com>]

On Thu, May 02, 2019 at 01:47:40PM -0600, Shuah Khan wrote:
> Add a sleep between detach and check for exportable devices to avoid
> the following segfault from libc-2.27.so
> 
> [ 6268.136108] usbip[5565]: segfault at 0 ip 00007f2a947bddfd sp 00007ffd1a8705e8 error 4 in libc-2.27.so[7f2a94703000+1e7000]
> 
> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
> ---
>  tools/testing/selftests/drivers/usb/usbip/usbip_test.sh | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/tools/testing/selftests/drivers/usb/usbip/usbip_test.sh b/tools/testing/selftests/drivers/usb/usbip/usbip_test.sh
> index 128f0ab24307..beacf24a8df7 100755
> --- a/tools/testing/selftests/drivers/usb/usbip/usbip_test.sh
> +++ b/tools/testing/selftests/drivers/usb/usbip/usbip_test.sh
> @@ -171,10 +171,14 @@ echo "Detach invalid port tests - expect invalid port error message";
>  src/usbip detach -p 100;
>  echo "=============================================================="
>  
> +# let detach complete. Avoid segfaults from libc-2.27.so
> +sleep 3;

That feels very "arbitrary", why do we "know" it will take at most 3
seconds?  I guess there's not much else we can do here except maybe
somehow watch sysfs until the device is really gone?

thanks,

greg k-h