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Commit 3ff50490 authored by Huazhong Tan's avatar Huazhong Tan Committed by David S. Miller
Browse files

net: hns3: fix a dead loop in hclge_cmd_csq_clean 



If head has invlid value then a dead loop can be triggered in
hclge_cmd_csq_clean. This patch adds sanity check for this case.

Fixes: 68c0a5c7 ("net: hns3: Add HNS3 IMP(Integrated Mgmt Proc) Cmd
Interface Support")
Signed-off-by: default avatarHuazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: default avatarPeng Li <lipeng321@huawei.com>
Signed-off-by: default avatarSalil Mehta <salil.mehta@huawei.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 0c963e8c

drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_cmd.c

+19 −0
Original line number Diff line number Diff line
@@ -31,6 +31,17 @@ static int hclge_ring_space(struct hclge_cmq_ring *ring) 
	return ring->desc_num - used - 1;

}



static int is_valid_csq_clean_head(struct hclge_cmq_ring *ring, int h)

{

	int u = ring->next_to_use;

	int c = ring->next_to_clean;



	if (unlikely(h >= ring->desc_num))

		return 0;



	return u > c ? (h > c && h <= u) : (h > c || h <= u);

}



static int hclge_alloc_cmd_desc(struct hclge_cmq_ring *ring)

{

	int size  = ring->desc_num * sizeof(struct hclge_desc);
@@ -141,6 +152,7 @@ static void hclge_cmd_init_regs(struct hclge_hw *hw) 


static int hclge_cmd_csq_clean(struct hclge_hw *hw)

{

	struct hclge_dev *hdev = (struct hclge_dev *)hw->back;

	struct hclge_cmq_ring *csq = &hw->cmq.csq;

	u16 ntc = csq->next_to_clean;

	struct hclge_desc *desc;
@@ -149,6 +161,13 @@ static int hclge_cmd_csq_clean(struct hclge_hw *hw) 


	desc = &csq->desc[ntc];

	head = hclge_read_dev(hw, HCLGE_NIC_CSQ_HEAD_REG);

	rmb(); /* Make sure head is ready before touch any data */



	if (!is_valid_csq_clean_head(csq, head)) {

		dev_warn(&hdev->pdev->dev, "wrong head (%d, %d-%d)\n", head,

			   csq->next_to_use, csq->next_to_clean);

		return 0;

	}



	while (head != ntc) {

		memset(desc, 0, sizeof(*desc));