diff options
| author | Netanel Belgazal <netanel@amazon.com> | 2019-12-10 11:27:44 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-01-04 13:41:11 +0100 |
| commit | 971932afde4ee53a7d386e898db0021111e0603b (patch) | |
| tree | b603206467e3db25d2e765e6869a2634dfa4adf9 /drivers | |
| parent | b524e0caa40e2e3951e9da188bb7ba32007b4cf2 (diff) | |
net: ena: fix napi handler misbehavior when the napi budget is zero
[ Upstream commit 24dee0c7478d1a1e00abdf5625b7f921467325dc ]
In netpoll the napi handler could be called with budget equal to zero.
Current ENA napi handler doesn't take that into consideration.
The napi handler handles Rx packets in a do-while loop.
Currently, the budget check happens only after decrementing the
budget, therefore the napi handler, in rare cases, could run over
MAX_INT packets.
In addition to that, this moves all budget related variables to int
calculation and stop mixing u32 to avoid ambiguity
Fixes: 1738cd3ed342 ("net: ena: Add a driver for Amazon Elastic Network Adapters (ENA)")
Signed-off-by: Netanel Belgazal <netanel@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/ethernet/amazon/ena/ena_netdev.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.c b/drivers/net/ethernet/amazon/ena/ena_netdev.c index 0780900b37c7..961f31c8356b 100644 --- a/drivers/net/ethernet/amazon/ena/ena_netdev.c +++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c @@ -1105,8 +1105,8 @@ static int ena_io_poll(struct napi_struct *napi, int budget) struct ena_ring *tx_ring, *rx_ring; struct ena_eth_io_intr_reg intr_reg; - u32 tx_work_done; - u32 rx_work_done; + int tx_work_done; + int rx_work_done = 0; int tx_budget; int napi_comp_call = 0; int ret; @@ -1122,7 +1122,11 @@ static int ena_io_poll(struct napi_struct *napi, int budget) } tx_work_done = ena_clean_tx_irq(tx_ring, tx_budget); - rx_work_done = ena_clean_rx_irq(rx_ring, napi, budget); + /* On netpoll the budget is zero and the handler should only clean the + * tx completions. + */ + if (likely(budget)) + rx_work_done = ena_clean_rx_irq(rx_ring, napi, budget); if ((budget > rx_work_done) && (tx_budget > tx_work_done)) { napi_complete_done(napi, rx_work_done); |