> To: Felipe Balbi <balbi@xxxxxxxxxx>; Greg Kroah-Hartman
> <gregkh@xxxxxxxxxxxxxxxxxxx>; linux-usb@xxxxxxxxxxxxxxx; Peter Chen
> <peter.chen@xxxxxxx>; Lee Jones <lee.jones@xxxxxxxxxx>; Alan Stern
> <stern@xxxxxxxxxxxxxxxxxxx>; Thomas Gleixner <tglx@xxxxxxxxxxxxx>; Dejin
> Zheng <zhengdejin5@xxxxxxxxx>; Sebastian Andrzej Siewior
> <bigeasy@xxxxxxxxxxxxx>; Ahmed S. Darwish <a.darwish@xxxxxxxxxxxxx>;
> Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>; Michal Nazarewicz
> <mina86@xxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> Subject: [PATCH] usb: udc: core: Use lock for soft_connect
>
> Use lock to guard against concurrent access for soft-connect/disconnect
> operations when writing to soft_connect sysfs.
>
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: 2ccea03a8f7e ("usb: gadget: introduce UDC Class")
> Signed-off-by: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>
Reviewed-by: Peter Chen <peter.chen@xxxxxxxxxx>
Peter
> ---
> drivers/usb/gadget/udc/core.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c
> index 6a62bbd01324..44c67e765167 100644
> --- a/drivers/usb/gadget/udc/core.c
> +++ b/drivers/usb/gadget/udc/core.c
> @@ -1530,7 +1530,9 @@ static ssize_t soft_connect_store(struct device *dev,
> {
> struct usb_udc *udc = container_of(dev, struct usb_udc, dev);
>
> + mutex_lock(&udc_lock);
> if (!udc->driver) {
> + mutex_unlock(&udc_lock);
> dev_err(dev, "soft-connect without a gadget driver\n");
> return -EOPNOTSUPP;
> }
> @@ -1542,10 +1544,12 @@ static ssize_t soft_connect_store(struct device
> *dev,
> usb_gadget_disconnect(udc->gadget);
> usb_gadget_udc_stop(udc);
> } else {
> + mutex_unlock(&udc_lock);
> dev_err(dev, "unsupported command '%s'\n", buf);
> return -EINVAL;
> }
>
> + mutex_unlock(&udc_lock);
> return n;
> }
> static DEVICE_ATTR_WO(soft_connect);
>
> base-commit: 4e0dcf62ab4cf917d0cbe751b8bf229a065248d4
> --
> 2.28.0
