On 2023/7/21 19:08, Greg KH Wrote:
> On Fri, Jul 21, 2023 at 06:00:15PM +0800, liulongfang wrote:
>> On systems that use ECC memory. The ECC error of the memory will
>> cause the USB controller to halt. It causes the usb_control_msg()
>> operation to fail.
>
> Why does ECC memory matter here?
>
This is a test conducted under a special test scenario.
ECC memory errors are caused by some test tools.
>> At this point, the returned buffer data is an abnormal value, and
>> continuing to use it will lead to incorrect results.
>>
>> Therefore, it is necessary to judge the return value and exit.
>>
>> Signed-off-by: liulongfang <liulongfang@xxxxxxxxxx>
>> ---
>> drivers/usb/core/hub.c | 10 ++++++++++
>> 1 file changed, 10 insertions(+)
>>
>> diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
>> index a739403a9e45..6a43198be263 100644
>> --- a/drivers/usb/core/hub.c
>> +++ b/drivers/usb/core/hub.c
>> @@ -4891,6 +4891,16 @@ hub_port_init(struct usb_hub *hub, struct usb_device *udev, int port1,
>> USB_DT_DEVICE << 8, 0,
>> buf, GET_DESCRIPTOR_BUFSIZE,
>> initial_descriptor_timeout);
>> + /* On systems that use ECC memory, ECC errors can
>> + * cause the USB controller to halt.
>> + * It causes this operation to fail. At this time,
>> + * the buf data is an abnormal value and needs to be exited.
>> + */
>> + if (r < 0) {
>> + kfree(buf);
>> + goto fail;
>> + }
>
> Are you sure this is correct? How was this tested? Seems to me that
> this will still return "success" if this code path ever happens, what am
You are right. I made a patch error here. The code modification should be like this:
if (r < 0) {
retval = r;
kfree(buf);
goto fail;
}
thanks,
Longfang.
> I missing?
>
> thanks,
>
> greg k-h
> .
>
