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net: hns3: fix a dead loop in hclge_cmd_csq_clean

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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: 68c0a5c706 ("net: hns3: Add HNS3 IMP(Integrated Mgmt Proc) Cmd
Interface Support")
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Huazhong Tan 2018-05-01 19:56:03 +01:00 committed by David S. Miller
parent 0c963e8c20
commit 3ff504908f
1 changed files with 19 additions and 0 deletions
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19
drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_cmd.c
View file

@ -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));