gve: fix the wrong AdminQ buffer overflow check

The 'tail' pointer is also free-running count, so it needs to be masked
as 'adminq_prod_cnt' does, to become an index value of AdminQ buffer.

Fixes: 5cdad90de6 ("gve: Batch AQ commands for creating and destroying queues.")
Signed-off-by: Haiyue Wang <haiyue.wang@intel.com>
Reviewed-by: Catherine Sullivan <csully@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Haiyue Wang 2021-07-14 15:34:59 +08:00 committed by David S. Miller
parent 82a1ffe57e
commit 63a9192b8f

View file

@ -322,7 +322,8 @@ static int gve_adminq_issue_cmd(struct gve_priv *priv,
tail = ioread32be(&priv->reg_bar0->adminq_event_counter);
// Check if next command will overflow the buffer.
if (((priv->adminq_prod_cnt + 1) & priv->adminq_mask) == tail) {
if (((priv->adminq_prod_cnt + 1) & priv->adminq_mask) ==
(tail & priv->adminq_mask)) {
int err;
// Flush existing commands to make room.
@ -332,7 +333,8 @@ static int gve_adminq_issue_cmd(struct gve_priv *priv,
// Retry.
tail = ioread32be(&priv->reg_bar0->adminq_event_counter);
if (((priv->adminq_prod_cnt + 1) & priv->adminq_mask) == tail) {
if (((priv->adminq_prod_cnt + 1) & priv->adminq_mask) ==
(tail & priv->adminq_mask)) {
// This should never happen. We just flushed the
// command queue so there should be enough space.
return -ENOMEM;