From f8d384a640dd32aaf0a05fec137ccbf0e986b09f Mon Sep 17 00:00:00 2001 From: Yinjun Zhang Date: Fri, 29 Oct 2021 13:29:02 +0200 Subject: [PATCH 1/2] nfp: fix NULL pointer access when scheduling dim work Each rx/tx ring has a related dim work, when rx/tx ring number is decreased by `ethtool -L`, the corresponding rx_ring or tx_ring is assigned NULL, while its related work is not destroyed. When scheduled, the work will access NULL pointer. Fixes: 9d32e4e7e9e1 ("nfp: add support for coalesce adaptive feature") Signed-off-by: Yinjun Zhang Signed-off-by: Louis Peens Signed-off-by: Simon Horman Signed-off-by: David S. Miller --- drivers/net/ethernet/netronome/nfp/nfp_net_common.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c index 5bfa22accf2c..f8b880c8e514 100644 --- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c +++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c @@ -2067,7 +2067,7 @@ static int nfp_net_poll(struct napi_struct *napi, int budget) if (napi_complete_done(napi, pkts_polled)) nfp_net_irq_unmask(r_vec->nfp_net, r_vec->irq_entry); - if (r_vec->nfp_net->rx_coalesce_adapt_on) { + if (r_vec->nfp_net->rx_coalesce_adapt_on && r_vec->rx_ring) { struct dim_sample dim_sample = {}; unsigned int start; u64 pkts, bytes; @@ -2082,7 +2082,7 @@ static int nfp_net_poll(struct napi_struct *napi, int budget) net_dim(&r_vec->rx_dim, dim_sample); } - if (r_vec->nfp_net->tx_coalesce_adapt_on) { + if (r_vec->nfp_net->tx_coalesce_adapt_on && r_vec->tx_ring) { struct dim_sample dim_sample = {}; unsigned int start; u64 pkts, bytes; From 17e712c6a1bade9dac02a7bf2b464746faa7e9a0 Mon Sep 17 00:00:00 2001 From: Yinjun Zhang Date: Fri, 29 Oct 2021 13:29:03 +0200 Subject: [PATCH 2/2] nfp: fix potential deadlock when canceling dim work When port is linked down, the process which has acquired rtnl_lock will wait for the in-progress dim work to finish, and the work also acquires rtnl_lock, which may cause deadlock. Currently IRQ_MOD registers can be configured by `ethtool -C` and dim work, and which will take effect depends on the execution order, rtnl_lock is useless here, so remove them. Fixes: 9d32e4e7e9e1 ("nfp: add support for coalesce adaptive feature") Signed-off-by: Yinjun Zhang Signed-off-by: Louis Peens Signed-off-by: Simon Horman Signed-off-by: David S. Miller --- drivers/net/ethernet/netronome/nfp/nfp_net_common.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c index f8b880c8e514..850bfdf83d0a 100644 --- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c +++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c @@ -3016,10 +3016,8 @@ static void nfp_net_rx_dim_work(struct work_struct *work) /* copy RX interrupt coalesce parameters */ value = (moder.pkts << 16) | (factor * moder.usec); - rtnl_lock(); nn_writel(nn, NFP_NET_CFG_RXR_IRQ_MOD(r_vec->rx_ring->idx), value); (void)nfp_net_reconfig(nn, NFP_NET_CFG_UPDATE_IRQMOD); - rtnl_unlock(); dim->state = DIM_START_MEASURE; } @@ -3047,10 +3045,8 @@ static void nfp_net_tx_dim_work(struct work_struct *work) /* copy TX interrupt coalesce parameters */ value = (moder.pkts << 16) | (factor * moder.usec); - rtnl_lock(); nn_writel(nn, NFP_NET_CFG_TXR_IRQ_MOD(r_vec->tx_ring->idx), value); (void)nfp_net_reconfig(nn, NFP_NET_CFG_UPDATE_IRQMOD); - rtnl_unlock(); dim->state = DIM_START_MEASURE; }