2018-04-11 07:37:40

by Jia-Ju Bai

Subject: [PATCH 3/3] infiniband: i40iw: Replace GFP_ATOMIC with GFP_KERNEL in i40iw_l2param_change

i40iw_l2param_change() is never called in atomic context.

i40iw_make_listen_node() is only set as ".l2_param_change"
in struct i40e_client_ops, and this function pointer is not called
in atomic context.

Despite never getting called from atomic context,
i40iw_l2param_change() 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 <[email protected]>
---
drivers/infiniband/hw/i40iw/i40iw_main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/infiniband/hw/i40iw/i40iw_main.c b/drivers/infiniband/hw/i40iw/i40iw_main.c
index 27590ae..b86bda8 100644
--- a/drivers/infiniband/hw/i40iw/i40iw_main.c
+++ b/drivers/infiniband/hw/i40iw/i40iw_main.c
@@ -1737,7 +1737,7 @@ static void i40iw_l2param_change(struct i40e_info *ldev, struct i40e_client *cli
return;


- work = kzalloc(sizeof(*work), GFP_ATOMIC);
+ work = kzalloc(sizeof(*work), GFP_KERNEL);
if (!work)
return;

--
1.9.1

2018-04-14 01:13:33

by Shiraz Saleem

Subject: Re: [PATCH 3/3] infiniband: i40iw: Replace GFP_ATOMIC with GFP_KERNEL in i40iw_l2param_change

On Wed, Apr 11, 2018 at 03:33:06PM +0800, Jia-Ju Bai wrote:
> i40iw_l2param_change() is never called in atomic context.
>
> i40iw_make_listen_node() is only set as ".l2_param_change"
> in struct i40e_client_ops, and this function pointer is not called
> in atomic context.
>
> Despite never getting called from atomic context,
> i40iw_l2param_change() 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 <[email protected]>
> ---
>

Acked-by: Shiraz Saleem <[email protected]>