From mboxrd@z Thu Jan 1 00:00:00 1970 From: jeff.evanson@gmail.com Date: Tue, 19 Apr 2022 19:26:34 -0600 Subject: [Intel-wired-lan] [PATCH v2 1/2] igc: Fix race in igc_xdp_xmit_zc In-Reply-To: <20220420012635.13733-1-jeff.evanson@qsc.com> References: <20220420012635.13733-1-jeff.evanson@qsc.com> Message-ID: <20220420012635.13733-2-jeff.evanson@qsc.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: intel-wired-lan@osuosl.org List-ID: From: Jeff Evanson In igc_xdp_xmit_zc, initialize next_to_use while holding the netif_tx_lock to prevent racing with other users of the tx ring. Fixes: 9acf59a752d4 (igc: Enable TX via AF_XDP zero-copy) --- drivers/net/ethernet/intel/igc/igc_main.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c index 1c00ee310c19..a36a18c84aeb 100644 --- a/drivers/net/ethernet/intel/igc/igc_main.c +++ b/drivers/net/ethernet/intel/igc/igc_main.c @@ -2598,7 +2598,7 @@ static void igc_xdp_xmit_zc(struct igc_ring *ring) struct netdev_queue *nq = txring_txq(ring); union igc_adv_tx_desc *tx_desc = NULL; int cpu = smp_processor_id(); - u16 ntu = ring->next_to_use; + u16 ntu; struct xdp_desc xdp_desc; u16 budget; @@ -2607,6 +2607,8 @@ static void igc_xdp_xmit_zc(struct igc_ring *ring) __netif_tx_lock(nq, cpu); + ntu = ring->next_to_use; + budget = igc_desc_unused(ring); while (xsk_tx_peek_desc(pool, &xdp_desc) && budget--) { -- 2.17.1