2018-04-11 07:37:14

by Jia-Ju Bai

Subject: [PATCH 2/3] infiniband: i40iw: Replace GFP_ATOMIC with GFP_KERNEL in i40iw_make_listen_node

i40iw_make_listen_node() is never called in atomic context.

i40iw_make_listen_node() is only called by i40iw_create_listen, which is
set as ".create_listen" in struct iw_cm_verbs.

Despite never getting called from atomic context,
i40iw_make_listen_node() 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_cm.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/infiniband/hw/i40iw/i40iw_cm.c b/drivers/infiniband/hw/i40iw/i40iw_cm.c
index 5230dd3..d021399 100644
--- a/drivers/infiniband/hw/i40iw/i40iw_cm.c
+++ b/drivers/infiniband/hw/i40iw/i40iw_cm.c
@@ -2834,7 +2834,7 @@ static struct i40iw_cm_listener *i40iw_make_listen_node(

if (!listener) {
/* create a CM listen node (1/2 node to compare incoming traffic to) */
- listener = kzalloc(sizeof(*listener), GFP_ATOMIC);
+ listener = kzalloc(sizeof(*listener), GFP_KERNEL);
if (!listener)
return NULL;
cm_core->stats_listen_nodes_created++;
--
1.9.1

2018-04-14 01:13:17

by Shiraz Saleem

Subject: Re: [PATCH 2/3] infiniband: i40iw: Replace GFP_ATOMIC with GFP_KERNEL in i40iw_make_listen_node

On Wed, Apr 11, 2018 at 03:32:48PM +0800, Jia-Ju Bai wrote:
> i40iw_make_listen_node() is never called in atomic context.
>
> i40iw_make_listen_node() is only called by i40iw_create_listen, which is
> set as ".create_listen" in struct iw_cm_verbs.
>
> Despite never getting called from atomic context,
> i40iw_make_listen_node() 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]>