netdev - [net-next 1/9] i40evf: Replace GFP_ATOMIC with GFP_KERNEL in i40evf_add

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Date:   Mon, 30 Apr 2018 10:00:51 -0700
From:   Jeff Kirsher <jeffrey.t.kirsher@...el.com>
To:     davem@...emloft.net
Cc:     Jia-Ju Bai <baijiaju1990@...il.com>, netdev@...r.kernel.org,
        nhorman@...hat.com, sassmann@...hat.com, jogreene@...hat.com,
        Jeff Kirsher <jeffrey.t.kirsher@...el.com>
Subject: [net-next 1/9] i40evf: Replace GFP_ATOMIC with GFP_KERNEL in i40evf_add_vlan

From: Jia-Ju Bai <baijiaju1990@...il.com>

i40evf_add_vlan() is never called in atomic context.

i40evf_add_vlan() is only called by i40evf_vlan_rx_add_vid(),
which is only set as ".ndo_vlan_rx_add_vid" in struct net_device_ops.
".ndo_vlan_rx_add_vid" is not called in atomic context.

Despite never getting called from atomic context,
i40evf_add_vlan() 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>
Tested-by: Andrew Bowers <andrewx.bowers@...el.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@...el.com>
---
 drivers/net/ethernet/intel/i40evf/i40evf_main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/i40evf/i40evf_main.c b/drivers/net/ethernet/intel/i40evf/i40evf_main.c
index 97cda4a8f8e0..8f775a82e2fa 100644
--- a/drivers/net/ethernet/intel/i40evf/i40evf_main.c
+++ b/drivers/net/ethernet/intel/i40evf/i40evf_main.c
@@ -681,7 +681,7 @@ i40evf_vlan_filter *i40evf_add_vlan(struct i40evf_adapter *adapter, u16 vlan)

 	f = i40evf_find_vlan(adapter, vlan);
 	if (!f) {
-		f = kzalloc(sizeof(*f), GFP_ATOMIC);
+		f = kzalloc(sizeof(*f), GFP_KERNEL);
 		if (!f)
 			goto clearout;

-- 
2.14.3