From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jia-Ju Bai Subject: [PATCH] net: usb: hso: Replace GFP_ATOMIC with GFP_KERNEL in hso_create_device Date: Tue, 10 Apr 2018 22:35:24 +0800 Message-ID: <1523370924-32425-1-git-send-email-baijiaju1990@gmail.com> Cc: linux-usb@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Jia-Ju Bai To: davem@davemloft.net, andreas@kemnade.info, johan@kernel.org, johannes.berg@intel.com, stephen@networkplumber.org, Linyu.Yuan@alcatel-sbell.com.cn Return-path: Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org 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 --- drivers/net/usb/hso.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/usb/hso.c b/drivers/net/usb/hso.c index d7a3379..3d7a33f 100644 --- a/drivers/net/usb/hso.c +++ b/drivers/net/usb/hso.c @@ -2332,7 +2332,7 @@ static struct hso_device *hso_create_device(struct usb_interface *intf, { struct hso_device *hso_dev; - hso_dev = kzalloc(sizeof(*hso_dev), GFP_ATOMIC); + hso_dev = kzalloc(sizeof(*hso_dev), GFP_KERNEL); if (!hso_dev) return NULL; -- 1.9.1