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From: Jia-Ju Bai <baijiaju1990@gmail.com>
To: stefan@osg.samsung.com, alex.aring@gmail.com
Cc: linux-wpan@vger.kernel.org, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org, Jia-Ju Bai <baijiaju1990@gmail.com>
Subject: [PATCH] net: ieee802154: atusb: Replace GFP_ATOMIC with GFP_KERNEL in atusb_probe
Date: Wed, 11 Apr 2018 10:14:10 +0800	[thread overview]
Message-ID: <1523412850-2260-1-git-send-email-baijiaju1990@gmail.com> (raw)

atusb_probe() is never called in atomic context.
This function is only set as ".probe" in struct usb_driver.

Despite never getting called from atomic context,
atusb_probe() calls usb_alloc_urb() 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@gmail.com>
---
 drivers/net/ieee802154/atusb.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ieee802154/atusb.c b/drivers/net/ieee802154/atusb.c
index ef68851..ab6a505 100644
--- a/drivers/net/ieee802154/atusb.c
+++ b/drivers/net/ieee802154/atusb.c
@@ -789,7 +789,7 @@ static int atusb_probe(struct usb_interface *interface,
 	atusb->tx_dr.bRequest = ATUSB_TX;
 	atusb->tx_dr.wValue = cpu_to_le16(0);
 
-	atusb->tx_urb = usb_alloc_urb(0, GFP_ATOMIC);
+	atusb->tx_urb = usb_alloc_urb(0, GFP_KERNEL);
 	if (!atusb->tx_urb)
 		goto fail;
 
-- 
1.9.1

             reply	other threads:[~2018-04-11  2:14 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-11  2:14 Jia-Ju Bai [this message]
2018-04-12 12:08 ` [PATCH] net: ieee802154: atusb: Replace GFP_ATOMIC with GFP_KERNEL in atusb_probe Stefan Schmidt

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