linux-kernel - [PATCH v2] net: nsci: Replace GFP_ATOMIC with GFP_KERNEL in ncsi_register

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Date:   Tue, 10 Apr 2018 09:16:46 +0800
From:   Jia-Ju Bai <baijiaju1990@...il.com>
To:     davem@...emloft.net, arnd@...db.de, sam@...dozajonas.com
Cc:     netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
        Jia-Ju Bai <baijiaju1990@...il.com>
Subject: [PATCH v2] net: nsci: Replace GFP_ATOMIC with GFP_KERNEL in ncsi_register_dev

ncsi_register_dev() is never called in atomic context.
This function is only called by ftgmac100_probe() in 
drivers/net/ethernet/faraday/ftgmac100.c.
And ftgmac100_probe() is only set as ".probe" in "struct platform_driver".

Despite never getting called from atomic context,
ncsi_register_dev() 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@...il.com>
---
v2:
* Modify the description of GFP_ATOMIC in v1.
  Thank Eric for good advice.
---
 net/ncsi/ncsi-manage.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ncsi/ncsi-manage.c b/net/ncsi/ncsi-manage.c
index 3fd3c39..6b5b5a0 100644
--- a/net/ncsi/ncsi-manage.c
+++ b/net/ncsi/ncsi-manage.c
@@ -1508,7 +1508,7 @@ struct ncsi_dev *ncsi_register_dev(struct net_device *dev,
 		return nd;

 	/* Create NCSI device */
-	ndp = kzalloc(sizeof(*ndp), GFP_ATOMIC);
+	ndp = kzalloc(sizeof(*ndp), GFP_KERNEL);
 	if (!ndp)
 		return NULL;

-- 
1.9.1