Re: [PATCH] net: usb: hso: Replace GFP_ATOMIC with GFP_KERNEL in hso_create_device
From: Johan Hovold
Date: Tue Apr 10 2018 - 10:59:40 EST
On Tue, Apr 10, 2018 at 10:35:24PM +0800, Jia-Ju Bai wrote:
> hso_create_device() is never called in atomic context.
>
> The call chains ending up at hso_create_device() are:
> [1] hso_create_device() <- hso_create_bulk_serial_device() <- hso_probe()
> [2] hso_create_device() <- hso_create_mux_serial_device() <- hso_probe()
> [3] hso_create_device() <- hso_create_net_device() <- hso_probe()
> hso_probe() is set as ".probe" in struct usb_driver,
> so it is not called in atomic context.
>
> Despite never getting called from atomic context,
> hso_create_device() calls kzalloc() with GFP_ATOMIC,
> which does not sleep for allocation.
> GFP_ATOMIC is not necessary and can be replaced with GFP_KERNEL,
> which can sleep and improve the possibility of sucessful allocation.
>
> This is found by a static analysis tool named DCNS written by myself.
> And I also manually check it.
>
> Signed-off-by: Jia-Ju Bai <baijiaju1990@xxxxxxxxx>
Thanks for the patch. This looks good to me.
Reviewed-by: Johan Hovold <johan@xxxxxxxxxx>
Johan