bpf: do not WARN in bpf_warn_invalid_xdp_action()

PATCH Superseded Paolo Abeni 4 participants 9 messages Nov 26, 2021 – Nov 29, 2021

Subsystems (30)

Networking Network drivers BPF Arm STM32 +26 more subsystems

lore

Share & tools

lore

Paolo Abeni

author maintainer

2021-11-26 11:21 UTC #0 lore raw

v2 cover bpf: do not WARN in bpf_warn_invalid_xdp_action()

The mentioned WARN is quite noisy, especially vs fuzzers and apparently used only to track the relevant BPF program and/or involved driver.

The first patch replace it with a pr_warn_once(), and the 2nd patch allow dumps relevant info to track the reported issue.

This is quite invasive, but the mentioned WARN makes the hunt for some bugs reported by syzkaller quite difficult.

v1 -> v2:
- do not include the device name for maps caller (Toke)

Paolo Abeni (2):
bpf: do not WARN in bpf_warn_invalid_xdp_action()
bpf: let bpf_warn_invalid_xdp_action() report more info

 drivers/net/ethernet/amazon/ena/ena_netdev.c           | 2 +-
 drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c          | 2 +-
 drivers/net/ethernet/cavium/thunder/nicvf_main.c       | 2 +-
 drivers/net/ethernet/freescale/dpaa/dpaa_eth.c         | 2 +-
 drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c       | 2 +-
 drivers/net/ethernet/freescale/enetc/enetc.c           | 2 +-
 drivers/net/ethernet/intel/i40e/i40e_txrx.c            | 2 +-
 drivers/net/ethernet/intel/i40e/i40e_xsk.c             | 2 +-
 drivers/net/ethernet/intel/ice/ice_txrx.c              | 2 +-
 drivers/net/ethernet/intel/ice/ice_xsk.c               | 2 +-
 drivers/net/ethernet/intel/igb/igb_main.c              | 2 +-
 drivers/net/ethernet/intel/igc/igc_main.c              | 2 +-
 drivers/net/ethernet/intel/ixgbe/ixgbe_main.c          | 2 +-
 drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c           | 2 +-
 drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c      | 2 +-
 drivers/net/ethernet/marvell/mvneta.c                  | 2 +-
 drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c        | 2 +-
 drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.c | 2 +-
 drivers/net/ethernet/mellanox/mlx4/en_rx.c             | 2 +-
 drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c       | 2 +-
 drivers/net/ethernet/microsoft/mana/mana_bpf.c         | 2 +-
 drivers/net/ethernet/netronome/nfp/nfp_net_common.c    | 2 +-
 drivers/net/ethernet/qlogic/qede/qede_fp.c             | 2 +-
 drivers/net/ethernet/sfc/rx.c                          | 2 +-
 drivers/net/ethernet/socionext/netsec.c                | 2 +-
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c      | 2 +-
 drivers/net/ethernet/ti/cpsw_priv.c                    | 2 +-
 drivers/net/hyperv/netvsc_bpf.c                        | 2 +-
 drivers/net/tun.c                                      | 2 +-
 drivers/net/veth.c                                     | 4 ++--
 drivers/net/virtio_net.c                               | 4 ++--
 drivers/net/xen-netfront.c                             | 2 +-
 include/linux/filter.h                                 | 2 +-
 kernel/bpf/cpumap.c                                    | 4 ++--
 kernel/bpf/devmap.c                                    | 4 ++--
 net/core/dev.c                                         | 2 +-
 net/core/filter.c                                      | 8 ++++----
 37 files changed, 44 insertions(+), 44 deletions(-)

Signature · 1 line

2.33.1

Paolo Abeni

author maintainer

2021-11-26 11:21 UTC #1 lore raw

PATCH v2 1/2 bpf: do not WARN in bpf_warn_invalid_xdp_action()

The WARN_ONCE() in bpf_warn_invalid_xdp_action() can be triggered by any bugged program, and even attaching a correct program to a NIC not supporting the given action.

The resulting splat, beyond polluting the logs, fouls automated tools:
e.g. a syzkaller reproducers using an XDP program returning an unsupported action will never pass validation.

Replace the WARN_ONCE with a less intrusive pr_warn_once().

Acked-by Toke Høiland-Jørgensen <[email protected]>

Signed-off-by Paolo Abeni <[email protected]>

---
 net/core/filter.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

net/core/filter.c +3 -3

index 8271624a19aa..5631acf3f10c 100644
@@ -8185,9 +8185,9 @@ void bpf_warn_invalid_xdp_action(u32 act)
 {
 	const u32 act_max = XDP_REDIRECT;
 
-	WARN_ONCE(1, "%s XDP return value %u, expect packet loss!\n",
-		  act > act_max ? "Illegal" : "Driver unsupported",
-		  act);
+	pr_warn_once("%s XDP return value %u, expect packet loss!\n",
+		     act > act_max ? "Illegal" : "Driver unsupported",
+		     act);
 }
 EXPORT_SYMBOL_GPL(bpf_warn_invalid_xdp_action);

Signature · 1 line

2.33.1

Paolo Abeni

author maintainer

2021-11-26 11:21 UTC #2 lore raw

PATCH v2 2/2 bpf: let bpf_warn_invalid_xdp_action() report more info

In reply to Paolo Abeni

In non trivial scenarios, the action id alone is not sufficient to identify the program causing the warning. Before the previous patch, the generated stack-trace pointed out at least the involved device driver.

Let's additionally include the program name and id, and the relevant device name.

If the user needs additional infos, he can fetch them via a kernel probe, leveraging the arguments added here.

v1 -> v2:
- do not include the device name for maps caller (Toke)

rfc -> v1:
- do not print the attach type, print the program name

Signed-off-by Paolo Abeni <[email protected]>

---
 drivers/net/ethernet/amazon/ena/ena_netdev.c           | 2 +-
 drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c          | 2 +-
 drivers/net/ethernet/cavium/thunder/nicvf_main.c       | 2 +-
 drivers/net/ethernet/freescale/dpaa/dpaa_eth.c         | 2 +-
 drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c       | 2 +-
 drivers/net/ethernet/freescale/enetc/enetc.c           | 2 +-
 drivers/net/ethernet/intel/i40e/i40e_txrx.c            | 2 +-
 drivers/net/ethernet/intel/i40e/i40e_xsk.c             | 2 +-
 drivers/net/ethernet/intel/ice/ice_txrx.c              | 2 +-
 drivers/net/ethernet/intel/ice/ice_xsk.c               | 2 +-
 drivers/net/ethernet/intel/igb/igb_main.c              | 2 +-
 drivers/net/ethernet/intel/igc/igc_main.c              | 2 +-
 drivers/net/ethernet/intel/ixgbe/ixgbe_main.c          | 2 +-
 drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c           | 2 +-
 drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c      | 2 +-
 drivers/net/ethernet/marvell/mvneta.c                  | 2 +-
 drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c        | 2 +-
 drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.c | 2 +-
 drivers/net/ethernet/mellanox/mlx4/en_rx.c             | 2 +-
 drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c       | 2 +-
 drivers/net/ethernet/microsoft/mana/mana_bpf.c         | 2 +-
 drivers/net/ethernet/netronome/nfp/nfp_net_common.c    | 2 +-
 drivers/net/ethernet/qlogic/qede/qede_fp.c             | 2 +-
 drivers/net/ethernet/sfc/rx.c                          | 2 +-
 drivers/net/ethernet/socionext/netsec.c                | 2 +-
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c      | 2 +-
 drivers/net/ethernet/ti/cpsw_priv.c                    | 2 +-
 drivers/net/hyperv/netvsc_bpf.c                        | 2 +-
 drivers/net/tun.c                                      | 2 +-
 drivers/net/veth.c                                     | 4 ++--
 drivers/net/virtio_net.c                               | 4 ++--
 drivers/net/xen-netfront.c                             | 2 +-
 include/linux/filter.h                                 | 2 +-
 kernel/bpf/cpumap.c                                    | 4 ++--
 kernel/bpf/devmap.c                                    | 4 ++--
 net/core/dev.c                                         | 2 +-
 net/core/filter.c                                      | 6 +++---
 37 files changed, 43 insertions(+), 43 deletions(-)

drivers/net/ethernet/amazon/ena/ena_netdev.c +1 -1

index 7d5d885d85d5..3b46f1df5609 100644
@@ -434,7 +434,7 @@ static int ena_xdp_execute(struct ena_ring *rx_ring, struct xdp_buff *xdp)
 		xdp_stat = &rx_ring->rx_stats.xdp_pass;
 		break;
 	default:
-		bpf_warn_invalid_xdp_action(verdict);
+		bpf_warn_invalid_xdp_action(rx_ring->netdev, xdp_prog, verdict);
 		xdp_stat = &rx_ring->rx_stats.xdp_invalid;
 	}

drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c +1 -1

index c8083df5e0ab..52fad0fdeacf 100644
@@ -195,7 +195,7 @@ bool bnxt_rx_xdp(struct bnxt *bp, struct bnxt_rx_ring_info *rxr, u16 cons,
 		*event |= BNXT_REDIRECT_EVENT;
 		break;
 	default:
-		bpf_warn_invalid_xdp_action(act);
+		bpf_warn_invalid_xdp_action(bp->dev, xdp_prog, act);
 		fallthrough;
 	case XDP_ABORTED:
 		trace_xdp_exception(bp->dev, xdp_prog, act);

drivers/net/ethernet/cavium/thunder/nicvf_main.c +1 -1

index bb45d5df2856..30450efccad7 100644
@@ -590,7 +590,7 @@ static inline bool nicvf_xdp_rx(struct nicvf *nic, struct bpf_prog *prog,
 		nicvf_xdp_sq_append_pkt(nic, sq, (u64)xdp.data, dma_addr, len);
 		return true;
 	default:
-		bpf_warn_invalid_xdp_action(action);
+		bpf_warn_invalid_xdp_action(nic->netdev, prog, action);
 		fallthrough;
 	case XDP_ABORTED:
 		trace_xdp_exception(nic->netdev, prog, action);

drivers/net/ethernet/freescale/dpaa/dpaa_eth.c +1 -1

index d6871437d951..c78883c3a2c8 100644
@@ -2623,7 +2623,7 @@ static u32 dpaa_run_xdp(struct dpaa_priv *priv, struct qm_fd *fd, void *vaddr,
 		}
 		break;
 	default:
-		bpf_warn_invalid_xdp_action(xdp_act);
+		bpf_warn_invalid_xdp_action(priv->net_dev, xdp_prog, xdp_act);
 		fallthrough;
 	case XDP_ABORTED:
 		trace_xdp_exception(priv->net_dev, xdp_prog, xdp_act);

drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c +1 -1

index 6451c8383639..4ef6b18005d9 100644
@@ -374,7 +374,7 @@ static u32 dpaa2_eth_run_xdp(struct dpaa2_eth_priv *priv,
 		dpaa2_eth_xdp_enqueue(priv, ch, fd, vaddr, rx_fq->flowid);
 		break;
 	default:
-		bpf_warn_invalid_xdp_action(xdp_act);
+		bpf_warn_invalid_xdp_action(priv->net_dev, xdp_prog, xdp_act);
 		fallthrough;
 	case XDP_ABORTED:
 		trace_xdp_exception(priv->net_dev, xdp_prog, xdp_act);

drivers/net/ethernet/freescale/enetc/enetc.c +1 -1

index 504e12554079..eacb41f86bdb 100644
@@ -1547,7 +1547,7 @@ static int enetc_clean_rx_ring_xdp(struct enetc_bdr *rx_ring,
 
 		switch (xdp_act) {
 		default:
-			bpf_warn_invalid_xdp_action(xdp_act);
+			bpf_warn_invalid_xdp_action(rx_ring->ndev, prog, xdp_act);
 			fallthrough;
 		case XDP_ABORTED:
 			trace_xdp_exception(rx_ring->ndev, prog, xdp_act);

drivers/net/ethernet/intel/i40e/i40e_txrx.c +1 -1

index 10a83e5385c7..b399ca649f09 100644
@@ -2322,7 +2322,7 @@ static int i40e_run_xdp(struct i40e_ring *rx_ring, struct xdp_buff *xdp)
 		result = I40E_XDP_REDIR;
 		break;
 	default:
-		bpf_warn_invalid_xdp_action(act);
+		bpf_warn_invalid_xdp_action(rx_ring->netdev, xdp_prog, act);
 		fallthrough;
 	case XDP_ABORTED:
 out_failure:

drivers/net/ethernet/intel/i40e/i40e_xsk.c +1 -1

index ea06e957393e..945b1bb9c6f4 100644
@@ -176,7 +176,7 @@ static int i40e_run_xdp_zc(struct i40e_ring *rx_ring, struct xdp_buff *xdp)
 			goto out_failure;
 		break;
 	default:
-		bpf_warn_invalid_xdp_action(act);
+		bpf_warn_invalid_xdp_action(rx_ring->netdev, xdp_prog, act);
 		fallthrough;
 	case XDP_ABORTED:
 out_failure:

drivers/net/ethernet/intel/ice/ice_txrx.c +1 -1

index bc3ba19dc88f..56940bb908bc 100644
@@ -561,7 +561,7 @@ ice_run_xdp(struct ice_rx_ring *rx_ring, struct xdp_buff *xdp,
 			goto out_failure;
 		return ICE_XDP_REDIR;
 	default:
-		bpf_warn_invalid_xdp_action(act);
+		bpf_warn_invalid_xdp_action(rx_ring->netdev, xdp_prog, act);
 		fallthrough;
 	case XDP_ABORTED:
 out_failure:

drivers/net/ethernet/intel/ice/ice_xsk.c +1 -1

index ff55cb415b11..eb68a5824e9a 100644
@@ -482,7 +482,7 @@ ice_run_xdp_zc(struct ice_rx_ring *rx_ring, struct xdp_buff *xdp,
 			goto out_failure;
 		break;
 	default:
-		bpf_warn_invalid_xdp_action(act);
+		bpf_warn_invalid_xdp_action(rx_ring->netdev, xdp_prog, act);
 		fallthrough;
 	case XDP_ABORTED:
 out_failure:

drivers/net/ethernet/intel/igb/igb_main.c +1 -1

index 18a019a47182..210f785432ab 100644
@@ -8422,7 +8422,7 @@ static struct sk_buff *igb_run_xdp(struct igb_adapter *adapter,
 		result = IGB_XDP_REDIR;
 		break;
 	default:
-		bpf_warn_invalid_xdp_action(act);
+		bpf_warn_invalid_xdp_action(adapter->netdev, xdp_prog, act);
 		fallthrough;
 	case XDP_ABORTED:
 out_failure:

drivers/net/ethernet/intel/igc/igc_main.c +1 -1

index 8e448288ee26..4ea212ddcc9b 100644
@@ -2231,7 +2231,7 @@ static int __igc_xdp_run_prog(struct igc_adapter *adapter,
 		return IGC_XDP_REDIRECT;
 		break;
 	default:
-		bpf_warn_invalid_xdp_action(act);
+		bpf_warn_invalid_xdp_action(adapter->netdev, prog, act);
 		fallthrough;
 	case XDP_ABORTED:
 out_failure:

drivers/net/ethernet/intel/ixgbe/ixgbe_main.c +1 -1

index 0f9f022260d7..265bc52aacf8 100644
@@ -2235,7 +2235,7 @@ static struct sk_buff *ixgbe_run_xdp(struct ixgbe_adapter *adapter,
 		result = IXGBE_XDP_REDIR;
 		break;
 	default:
-		bpf_warn_invalid_xdp_action(act);
+		bpf_warn_invalid_xdp_action(rx_ring->netdev, xdp_prog, act);
 		fallthrough;
 	case XDP_ABORTED:
 out_failure:

drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c +1 -1

index db2bc58dfcfd..b3fd8e5cd85b 100644
@@ -131,7 +131,7 @@ static int ixgbe_run_xdp_zc(struct ixgbe_adapter *adapter,
 			goto out_failure;
 		break;
 	default:
-		bpf_warn_invalid_xdp_action(act);
+		bpf_warn_invalid_xdp_action(rx_ring->netdev, xdp_prog, act);
 		fallthrough;
 	case XDP_ABORTED:
 out_failure:

drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c +1 -1

index b1dfbaff8b31..2459ecf65125 100644
@@ -1070,7 +1070,7 @@ static struct sk_buff *ixgbevf_run_xdp(struct ixgbevf_adapter *adapter,
 			goto out_failure;
 		break;
 	default:
-		bpf_warn_invalid_xdp_action(act);
+		bpf_warn_invalid_xdp_action(rx_ring->netdev, xdp_prog, act);
 		fallthrough;
 	case XDP_ABORTED:
 out_failure:

drivers/net/ethernet/marvell/mvneta.c +1 -1

index 80e4b500695e..f0ba8d846e28 100644
@@ -2212,7 +2212,7 @@ mvneta_run_xdp(struct mvneta_port *pp, struct mvneta_rx_queue *rxq,
 			mvneta_xdp_put_buff(pp, rxq, xdp, sinfo, sync);
 		break;
 	default:
-		bpf_warn_invalid_xdp_action(act);
+		bpf_warn_invalid_xdp_action(pp->dev, prog, act);
 		fallthrough;
 	case XDP_ABORTED:
 		trace_xdp_exception(pp->dev, prog, act);

drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c +1 -1

index 97bd2ee8a010..2880c587a50d 100644
@@ -3823,7 +3823,7 @@ mvpp2_run_xdp(struct mvpp2_port *port, struct bpf_prog *prog,
 		}
 		break;
 	default:
-		bpf_warn_invalid_xdp_action(act);
+		bpf_warn_invalid_xdp_action(port->dev, prog, act);
 		fallthrough;
 	case XDP_ABORTED:
 		trace_xdp_exception(port->dev, prog, act);

drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.c +1 -1

index 0cc6353254bf..7c4068c5d1ac 100644
@@ -1198,7 +1198,7 @@ static bool otx2_xdp_rcv_pkt_handler(struct otx2_nic *pfvf,
 		put_page(page);
 		break;
 	default:
-		bpf_warn_invalid_xdp_action(act);
+		bpf_warn_invalid_xdp_action(pfvf->netdev, prog, act);
 		break;
 	case XDP_ABORTED:
 		trace_xdp_exception(pfvf->netdev, prog, act);

drivers/net/ethernet/mellanox/mlx4/en_rx.c +1 -1

index 650e6a1844ae..8cfc649f226b 100644
@@ -812,7 +812,7 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 				trace_xdp_exception(dev, xdp_prog, act);
 				goto xdp_drop_no_cnt; /* Drop on xmit failure */
 			default:
-				bpf_warn_invalid_xdp_action(act);
+				bpf_warn_invalid_xdp_action(dev, xdp_prog, act);
 				fallthrough;
 			case XDP_ABORTED:
 				trace_xdp_exception(dev, xdp_prog, act);

drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c +1 -1

index 2f0df5cc1a2d..338d65e2c9ce 100644
@@ -151,7 +151,7 @@ bool mlx5e_xdp_handle(struct mlx5e_rq *rq, struct mlx5e_dma_info *di,
 		rq->stats->xdp_redirect++;
 		return true;
 	default:
-		bpf_warn_invalid_xdp_action(act);
+		bpf_warn_invalid_xdp_action(rq->netdev, prog, act);
 		fallthrough;
 	case XDP_ABORTED:
 xdp_abort:

drivers/net/ethernet/microsoft/mana/mana_bpf.c +1 -1

index 1bc8ff388341..1d2f948b5c00 100644
@@ -60,7 +60,7 @@ u32 mana_run_xdp(struct net_device *ndev, struct mana_rxq *rxq,
 		break;
 
 	default:
-		bpf_warn_invalid_xdp_action(act);
+		bpf_warn_invalid_xdp_action(ndev, prog, act);
 	}
 
 out:

drivers/net/ethernet/netronome/nfp/nfp_net_common.c +1 -1

index 6e38da4ad554..79257ec41987 100644
@@ -1944,7 +1944,7 @@ static int nfp_net_rx(struct nfp_net_rx_ring *rx_ring, int budget)
 							    xdp_prog, act);
 				continue;
 			default:
-				bpf_warn_invalid_xdp_action(act);
+				bpf_warn_invalid_xdp_action(dp->netdev, xdp_prog, act);
 				fallthrough;
 			case XDP_ABORTED:
 				trace_xdp_exception(dp->netdev, xdp_prog, act);

drivers/net/ethernet/qlogic/qede/qede_fp.c +1 -1

index e113fbd56e86..d1102686b09a 100644
@@ -1153,7 +1153,7 @@ static bool qede_rx_xdp(struct qede_dev *edev,
 		qede_rx_bd_ring_consume(rxq);
 		break;
 	default:
-		bpf_warn_invalid_xdp_action(act);
+		bpf_warn_invalid_xdp_action(edev->ndev, prog, act);
 		fallthrough;
 	case XDP_ABORTED:
 		trace_xdp_exception(edev->ndev, prog, act);

drivers/net/ethernet/sfc/rx.c +1 -1

index 606750938b89..2375cef577e4 100644
@@ -338,7 +338,7 @@ static bool efx_do_xdp(struct efx_nic *efx, struct efx_channel *channel,
 		break;
 
 	default:
-		bpf_warn_invalid_xdp_action(xdp_act);
+		bpf_warn_invalid_xdp_action(efx->net_dev, xdp_prog, xdp_act);
 		efx_free_rx_buffers(rx_queue, rx_buf, 1);
 		channel->n_rx_xdp_bad_drops++;
 		trace_xdp_exception(efx->net_dev, xdp_prog, xdp_act);

drivers/net/ethernet/socionext/netsec.c +1 -1

index de7d8bf2c226..25dcd8eda5fc 100644
@@ -933,7 +933,7 @@ static u32 netsec_run_xdp(struct netsec_priv *priv, struct bpf_prog *prog,
 		}
 		break;
 	default:
-		bpf_warn_invalid_xdp_action(act);
+		bpf_warn_invalid_xdp_action(priv->ndev, prog, act);
 		fallthrough;
 	case XDP_ABORTED:
 		trace_xdp_exception(priv->ndev, prog, act);

drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +1 -1

index 6d86b14c285f..a6ef40576615 100644
@@ -4679,7 +4679,7 @@ static int __stmmac_xdp_run_prog(struct stmmac_priv *priv,
 			res = STMMAC_XDP_REDIRECT;
 		break;
 	default:
-		bpf_warn_invalid_xdp_action(act);
+		bpf_warn_invalid_xdp_action(priv->dev, prog, act);
 		fallthrough;
 	case XDP_ABORTED:
 		trace_xdp_exception(priv->dev, prog, act);

drivers/net/ethernet/ti/cpsw_priv.c +1 -1

index c99dd9735087..67c4009fd16c 100644
@@ -1366,7 +1366,7 @@ int cpsw_run_xdp(struct cpsw_priv *priv, int ch, struct xdp_buff *xdp,
 		xdp_do_flush_map();
 		break;
 	default:
-		bpf_warn_invalid_xdp_action(act);
+		bpf_warn_invalid_xdp_action(ndev, prog, act);
 		fallthrough;
 	case XDP_ABORTED:
 		trace_xdp_exception(ndev, prog, act);

drivers/net/hyperv/netvsc_bpf.c +1 -1

index aa877da113f8..7856905414eb 100644
@@ -68,7 +68,7 @@ u32 netvsc_run_xdp(struct net_device *ndev, struct netvsc_channel *nvchan,
 		break;
 
 	default:
-		bpf_warn_invalid_xdp_action(act);
+		bpf_warn_invalid_xdp_action(ndev, prog, act);
 	}
 
 out:

drivers/net/tun.c +1 -1

index 1572878c3403..0e5d2272f63a 100644
@@ -1551,7 +1551,7 @@ static int tun_xdp_act(struct tun_struct *tun, struct bpf_prog *xdp_prog,
 	case XDP_PASS:
 		break;
 	default:
-		bpf_warn_invalid_xdp_action(act);
+		bpf_warn_invalid_xdp_action(tun->dev, xdp_prog, act);
 		fallthrough;
 	case XDP_ABORTED:
 		trace_xdp_exception(tun->dev, xdp_prog, act);

drivers/net/veth.c +2 -2

index 38f6da24f460..700cc9374f9c 100644
@@ -644,7 +644,7 @@ static struct xdp_frame *veth_xdp_rcv_one(struct veth_rq *rq,
 			rcu_read_unlock();
 			goto xdp_xmit;
 		default:
-			bpf_warn_invalid_xdp_action(act);
+			bpf_warn_invalid_xdp_action(rq->dev, xdp_prog, act);
 			fallthrough;
 		case XDP_ABORTED:
 			trace_xdp_exception(rq->dev, xdp_prog, act);

@@ -794,7 +794,7 @@ static struct sk_buff *veth_xdp_rcv_skb(struct veth_rq *rq,
 		rcu_read_unlock();
 		goto xdp_xmit;
 	default:
-		bpf_warn_invalid_xdp_action(act);
+		bpf_warn_invalid_xdp_action(rq->dev, xdp_prog, act);
 		fallthrough;
 	case XDP_ABORTED:
 		trace_xdp_exception(rq->dev, xdp_prog, act);

drivers/net/virtio_net.c +2 -2

index c74af526d79b..072130c936ea 100644
@@ -812,7 +812,7 @@ static struct sk_buff *receive_small(struct net_device *dev,
 			rcu_read_unlock();
 			goto xdp_xmit;
 		default:
-			bpf_warn_invalid_xdp_action(act);
+			bpf_warn_invalid_xdp_action(vi->dev, xdp_prog, act);
 			fallthrough;
 		case XDP_ABORTED:
 			trace_xdp_exception(vi->dev, xdp_prog, act);

@@ -1025,7 +1025,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
 			rcu_read_unlock();
 			goto xdp_xmit;
 		default:
-			bpf_warn_invalid_xdp_action(act);
+			bpf_warn_invalid_xdp_action(vi->dev, xdp_prog, act);
 			fallthrough;
 		case XDP_ABORTED:
 			trace_xdp_exception(vi->dev, xdp_prog, act);

drivers/net/xen-netfront.c +1 -1

index 911f43986a8c..7b7eb617051a 100644
@@ -930,7 +930,7 @@ static u32 xennet_run_xdp(struct netfront_queue *queue, struct page *pdata,
 		break;
 
 	default:
-		bpf_warn_invalid_xdp_action(act);
+		bpf_warn_invalid_xdp_action(queue->info->netdev, prog, act);
 	}
 
 	return act;

include/linux/filter.h +1 -1

index b6a216eb217a..0769d7f18102 100644
@@ -1030,7 +1030,7 @@ void xdp_do_flush(void);
  */
 #define xdp_do_flush_map xdp_do_flush
 
-void bpf_warn_invalid_xdp_action(u32 act);
+void bpf_warn_invalid_xdp_action(struct net_device *dev, struct bpf_prog *prog, u32 act);
 
 #ifdef CONFIG_INET
 struct sock *bpf_run_sk_reuseport(struct sock_reuseport *reuse, struct sock *sk,

kernel/bpf/cpumap.c +2 -2

index 585b2b77ccc4..0421061d95f1 100644
@@ -195,7 +195,7 @@ static void cpu_map_bpf_prog_run_skb(struct bpf_cpu_map_entry *rcpu,
 			}
 			return;
 		default:
-			bpf_warn_invalid_xdp_action(act);
+			bpf_warn_invalid_xdp_action(NULL, rcpu->prog, act);
 			fallthrough;
 		case XDP_ABORTED:
 			trace_xdp_exception(skb->dev, rcpu->prog, act);

@@ -254,7 +254,7 @@ static int cpu_map_bpf_prog_run_xdp(struct bpf_cpu_map_entry *rcpu,
 			}
 			break;
 		default:
-			bpf_warn_invalid_xdp_action(act);
+			bpf_warn_invalid_xdp_action(NULL, rcpu->prog, act);
 			fallthrough;
 		case XDP_DROP:
 			xdp_return_frame(xdpf);

kernel/bpf/devmap.c +2 -2

index f02d04540c0c..6feea293ff10 100644
@@ -348,7 +348,7 @@ static int dev_map_bpf_prog_run(struct bpf_prog *xdp_prog,
 				frames[nframes++] = xdpf;
 			break;
 		default:
-			bpf_warn_invalid_xdp_action(act);
+			bpf_warn_invalid_xdp_action(NULL, xdp_prog, act);
 			fallthrough;
 		case XDP_ABORTED:
 			trace_xdp_exception(dev, xdp_prog, act);

@@ -507,7 +507,7 @@ static u32 dev_map_bpf_prog_run_skb(struct sk_buff *skb, struct bpf_dtab_netdev
 		__skb_push(skb, skb->mac_len);
 		break;
 	default:
-		bpf_warn_invalid_xdp_action(act);
+		bpf_warn_invalid_xdp_action(NULL, dst->xdp_prog, act);
 		fallthrough;
 	case XDP_ABORTED:
 		trace_xdp_exception(dst->dev, dst->xdp_prog, act);

net/core/dev.c +1 -1

index 823917de0d2b..26801035c447 100644
@@ -4705,7 +4705,7 @@ static u32 netif_receive_generic_xdp(struct sk_buff *skb,
 	case XDP_PASS:
 		break;
 	default:
-		bpf_warn_invalid_xdp_action(act);
+		bpf_warn_invalid_xdp_action(skb->dev, xdp_prog, act);
 		fallthrough;
 	case XDP_ABORTED:
 		trace_xdp_exception(skb->dev, xdp_prog, act);

net/core/filter.c +3 -3

index 5631acf3f10c..75922ff59c3c 100644
@@ -8181,13 +8181,13 @@ static bool xdp_is_valid_access(int off, int size,
 	return __is_valid_xdp_access(off, size);
 }
 
-void bpf_warn_invalid_xdp_action(u32 act)
+void bpf_warn_invalid_xdp_action(struct net_device *dev, struct bpf_prog *prog, u32 act)
 {
 	const u32 act_max = XDP_REDIRECT;
 
-	pr_warn_once("%s XDP return value %u, expect packet loss!\n",
+	pr_warn_once("%s XDP return value %u on prog %s (id %d) dev %s, expect packet loss!\n",
 		     act > act_max ? "Illegal" : "Driver unsupported",
-		     act);
+		     act, prog->aux->name, prog->aux->id, dev->name ? dev->name : "");
 }
 EXPORT_SYMBOL_GPL(bpf_warn_invalid_xdp_action);

Signature · 1 line

2.33.1

Toke Høiland-Jørgensen

Acked-by on v2 2/2

2021-11-26 12:05 UTC #3 lore raw

Re: [PATCH net-next v2 2/2] bpf: let bpf_warn_invalid_xdp_action() report more info

Quoted 11 lines · Paolo Abeni

In non trivial scenarios, the action id alone is not sufficient to identify the program causing the warning. Before the previous patch, the generated stack-trace pointed out at least the involved device driver.
Let's additionally include the program name and id, and the relevant device name.
If the user needs additional infos, he can fetch them via a kernel probe, leveraging the arguments added here.

Quoted 7 lines

v1 -> v2:
- do not include the device name for maps caller (Toke)
rfc -> v1:
- do not print the attach type, print the program name
Signed-off-by Paolo Abeni <[email protected]>

Acked-by Toke Høiland-Jørgensen <[email protected]>

Jakub Kicinski

maintainer

2021-11-26 18:28 UTC #4 lore raw

Re: [PATCH net-next v2 2/2] bpf: let bpf_warn_invalid_xdp_action() report more info

In reply to Paolo Abeni

net/core/filter.c static bool xdp_is_valid_access(int off, int size, · line 8191

Quoted 11 lines · On Fri, 26 Nov 2021 12:19:11 +0100 Paolo Abeni wrote:

net/core/filter.c +3 -3

-void bpf_warn_invalid_xdp_action(u32 act)
+void bpf_warn_invalid_xdp_action(struct net_device *dev, struct bpf_prog *prog, u32 act)
 {
 	const u32 act_max = XDP_REDIRECT;
 
-	pr_warn_once("%s XDP return value %u, expect packet loss!\n",
+	pr_warn_once("%s XDP return value %u on prog %s (id %d) dev %s, expect packet loss!\n",
 		     act > act_max ? "Illegal" : "Driver unsupported",
-		     act);
+		     act, prog->aux->name, prog->aux->id, dev->name ? dev->name : "");
 }

Since we have to touch all the drivers each time the prototype of this function is changed - would it make sense to pass in rxq instead? It has more info which may become useful at some point.

Paolo Abeni

author maintainer

2021-11-26 18:59 UTC #5 lore raw

Re: [PATCH net-next v2 2/2] bpf: let bpf_warn_invalid_xdp_action() report more info

Quoted 6 lines · Jakub Kicinski

Quoted 5 lines · On Fri, 26 Nov 2021 12:19:11 +0100 Paolo Abeni wrote:

net/core/filter.c +1 -1

-void bpf_warn_invalid_xdp_action(u32 act)
+void bpf_warn_invalid_xdp_action(struct net_device *dev, struct bpf_prog *prog, u32 act)
 {
 	const u32 act_max = XDP_REDIRECT;

Quoted 10 lines

net/core/filter.c static bool xdp_is_valid_access(int off, int size, · line 8191
Quoted 6 lines
net/core/filter.c +2 -2
-	pr_warn_once("%s XDP return value %u, expect packet loss!\n",
+	pr_warn_once("%s XDP return value %u on prog %s (id %d) dev %s, expect packet loss!\n",
 		     act > act_max ? "Illegal" : "Driver unsupported",
-		     act);
+		     act, prog->aux->name, prog->aux->id, dev->name ? dev->name : "");
 }
Since we have to touch all the drivers each time the prototype of this function is changed - would it make sense to pass in rxq instead? It has more info which may become useful at some point.

I *think* for this specific scenario the device name provides all the necessary info - the users need to know the driver causing the issue.

Others similar xdp helpers - e.g. trace_xdp_exception() - have the same arguments list used here. If the rxq is useful I guess we will have to change even them, and touch all the drivers anyway.

Cheers,

Paolo

Paolo Abeni

author maintainer

2021-11-29 14:58 UTC #6 lore raw

Re: [PATCH net-next v2 2/2] bpf: let bpf_warn_invalid_xdp_action() report more info

Hello,

Quoted 18 lines · Paolo Abeni

Quoted 6 lines · Jakub Kicinski
Quoted 5 lines · On Fri, 26 Nov 2021 12:19:11 +0100 Paolo Abeni wrote:
net/core/filter.c +1 -1
-void bpf_warn_invalid_xdp_action(u32 act)
+void bpf_warn_invalid_xdp_action(struct net_device *dev, struct bpf_prog *prog, u32 act)
 {
 	const u32 act_max = XDP_REDIRECT;
Quoted 10 lines
net/core/filter.c static bool xdp_is_valid_access(int off, int size, · line 8191
Quoted 6 lines
net/core/filter.c +2 -2
-	pr_warn_once("%s XDP return value %u, expect packet loss!\n",
+	pr_warn_once("%s XDP return value %u on prog %s (id %d) dev %s, expect packet loss!\n",
 		     act > act_max ? "Illegal" : "Driver unsupported",
-		     act);
+		     act, prog->aux->name, prog->aux->id, dev->name ? dev->name : "");
 }
Since we have to touch all the drivers each time the prototype of this function is changed - would it make sense to pass in rxq instead? It has more info which may become useful at some point.

Quoted 6 lines

I *think* for this specific scenario the device name provides all the necessary info - the users need to know the driver causing the issue.
Others similar xdp helpers - e.g. trace_xdp_exception() - have the same arguments list used here. If the rxq is useful I guess we will have to change even them, and touch all the drivers anyway.

Following the above reasoning I'm going to post v3 with the same argument list used here, unless someone stops me soon ;)

Thanks,

Paolo

Jakub Kicinski

maintainer

2021-11-29 18:52 UTC #7 lore raw

Re: [PATCH net-next v2 2/2] bpf: let bpf_warn_invalid_xdp_action() report more info

Quoted 9 lines · On Mon, 29 Nov 2021 15:56:33 +0100 Paolo Abeni wrote:

Quoted 8 lines · Paolo Abeni
Quoted 3 lines · Jakub Kicinski
Since we have to touch all the drivers each time the prototype of this function is changed - would it make sense to pass in rxq instead? It has more info which may become useful at some point.
I *think* for this specific scenario the device name provides all the necessary info - the users need to know the driver causing the issue.

Quoted 6 lines

Quoted 3 lines
Others similar xdp helpers - e.g. trace_xdp_exception() - have the same arguments list used here. If the rxq is useful I guess we will have to change even them, and touch all the drivers anyway.
Following the above reasoning I'm going to post v3 with the same argument list used here, unless someone stops me soon ;)

It's fine, it was just a thought :)

kernel test robot

build bot

2021-11-26 20:55 UTC #8 lore raw

Re: [PATCH net-next v2 2/2] bpf: let bpf_warn_invalid_xdp_action() report more info

In reply to Paolo Abeni

Thank you for the patch! Perhaps something to improve:

Hi Paolo,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on net-next/master]

url:    https://github.com/0day-ci/linux/commits/Paolo-Abeni/bpf-do-not-WARN-in-bpf_warn_invalid_xdp_action/20211126-192252
base:   https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git 35bf8c86eeb8ae609f61c43aeab3b530fedcf1b4
config: riscv-randconfig-r036-20211126 (https://download.01.org/0day-ci/archive/20211127/202111270414.XuXZgoE5-lkp(a)intel.com/config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 5162b558d8c0b542e752b037e72a69d5fd51eb1e)

reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross
# install riscv cross compiling tool for clang build
# apt-get install binutils-riscv64-linux-gnu
# https://github.com/0day-ci/linux/commit/afb829c16c3bd86f86b24c880601cea9e21c5d3e
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Paolo-Abeni/bpf-do-not-WARN-in-bpf_warn_invalid_xdp_action/20211126-192252 git checkout afb829c16c3bd86f86b24c880601cea9e21c5d3e
# save the config file to linux build tree
mkdir build_dir
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=riscv SHELL=/bin/bash net/core/

If you fix the issue, kindly add following tag as appropriate

Reported-by kernel test robot <[email protected]>

All warnings (new ones prefixed by >>):

>> net/core/filter.c:8190:50: warning: address of array 'dev->name' will always evaluate to 'true' [-Wpointer-bool-conversion]
                        act, prog->aux->name, prog->aux->id, dev->name ? dev->name : "");
                                                             ~~~~~^~~~ ~
   include/linux/printk.h:608:42: note: expanded from macro 'pr_warn_once'
           printk_once(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
                                                   ^~~~~~~~~~~
   include/linux/printk.h:589:30: note: expanded from macro 'printk_once'
           DO_ONCE_LITE(printk, fmt, ##__VA_ARGS__)
                                       ^~~~~~~~~~~
   include/linux/once_lite.h:11:32: note: expanded from macro 'DO_ONCE_LITE'
           DO_ONCE_LITE_IF(true, func, ##__VA_ARGS__)
                                         ^~~~~~~~~~~
   include/linux/once_lite.h:19:9: note: expanded from macro 'DO_ONCE_LITE_IF'
                           func(__VA_ARGS__);                              \
                                ^~~~~~~~~~~
   include/linux/printk.h:450:60: note: expanded from macro 'printk'
   #define printk(fmt, ...) printk_index_wrap(_printk, fmt, ##__VA_ARGS__)
                                                              ^~~~~~~~~~~
   include/linux/printk.h:422:19: note: expanded from macro 'printk_index_wrap'
                   _p_func(_fmt, ##__VA_ARGS__);                           \
                                   ^~~~~~~~~~~

1 warning generated.

vim +8190 net/core/filter.c

8183
8184 void bpf_warn_invalid_xdp_action(struct net_device *dev, struct bpf_prog *prog, u32 act)
8185 {
8186 const u32 act_max = XDP_REDIRECT;
8187
8188 pr_warn_once("%s XDP return value %u on prog %s (id %d) dev %s, expect packet loss!\n",
8189 act > act_max ? "Illegal" : "Driver unsupported",

> 8190			     act, prog->aux->name, prog->aux->id, dev->name ? dev->name : "");

8191 }
8192 EXPORT_SYMBOL_GPL(bpf_warn_invalid_xdp_action);
8193

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org