After checking all possible call chains to atmtcp_v_send() here, my tool finds that atmtcp_v_send() is never called in atomic context. And this function is assigned to a function pointer "dev->ops->send", which is only called by vcc_sendmsg() (net/atm/common.c) through vcc->dev->ops->send(), and vcc_sendmsg() calls schedule(), it indicates that atmtcp_v_send() can call functions which may sleep. Thus GFP_ATOMIC is not necessary, and it can be replaced with GFP_KERNEL.
This is found by a static analysis tool named DCNS written by myself. Signed-off-by: Jia-Ju Bai <baijiaju1...@gmail.com> --- drivers/atm/atmtcp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/atm/atmtcp.c b/drivers/atm/atmtcp.c index afebeb1c..f7a27ed 100644 --- a/drivers/atm/atmtcp.c +++ b/drivers/atm/atmtcp.c @@ -210,7 +210,7 @@ static int atmtcp_v_send(struct atm_vcc *vcc,struct sk_buff *skb) return -ENOLINK; } size = skb->len+sizeof(struct atmtcp_hdr); - new_skb = atm_alloc_charge(out_vcc,size,GFP_ATOMIC); + new_skb = atm_alloc_charge(out_vcc,size,GFP_KERNEL); if (!new_skb) { if (vcc->pop) vcc->pop(vcc,skb); else dev_kfree_skb(skb); -- 1.7.9.5