From patchwork Thu Jan 9 04:30:57 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jakub Kicinski X-Patchwork-Id: 13932025 X-Patchwork-Delegate: kuba@kernel.org Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A3C5920C006 for ; Thu, 9 Jan 2025 04:31:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736397060; cv=none; b=gRe14sON8hj4LkaZx0ABVFJqBo4pa85UsS44+7EKoJKmC+aHH4bAAMDEpWiIU2zBap4k63iryX4u+1PvJB06OOEjnPaEiuMRrf6TP2h8kFapC+/negde2gcaSYTjgS2vPkSD7VMeOH8Z1LmqF46IV/CWFt/VzOf5wyxoODJynEc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736397060; c=relaxed/simple; bh=u52Td5MsJMyfQGpO8yojmWul1RcM7DlXfDOr8NhTcUM=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=LlUK+R7+RwDSYbHMfqmTyK2sCDZK4WIE0fzKU4rfTwcsBadNJwinURihVODAavAwYFY79JmL9zbblbJH4OQYQZ8gMmI3Cyi/EgZacXAzaOhoTqHGXUJIXx6pL7RkblcLlK1PqPD9UWYDvaA+u2oDDQSv2oE1b0RyGRBncEq1IG4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=LhOuVK28; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="LhOuVK28" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C47C4C4CED2; Thu, 9 Jan 2025 04:30:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1736397060; bh=u52Td5MsJMyfQGpO8yojmWul1RcM7DlXfDOr8NhTcUM=; h=From:To:Cc:Subject:Date:From; b=LhOuVK28yitH7z+KSjd7H6ubCIuq10v/mgPFh8I74BPBL8+JP2jrFfR2XoC9yNbyM BX4coNaOVj2LRiSwn4ZxvYb+ujDUL05yPxsS66yHcH7e8SWMmgShflMX2MV2TvauZl D4gvRTH7QQ2040J101Wjitre4LFgTGmVLPHkDL8dDPBtkqHX/rIi4Xw06TtAZW1kFB EhYAOiCFpAsSlHGV2pe4bcB0HYh1xW4JIqxVc3E0XOOU/4ICDXlTcuw6a9tcQJ3V5i Zv+VYSAvJANxL4folf1UEqfGFXOWeS6FsIMLScByU1Ey+vq6m0+/6r+uuhQiL0qtLJ J7sJ0R+h6itlQ== From: Jakub Kicinski To: davem@davemloft.net Cc: netdev@vger.kernel.org, edumazet@google.com, pabeni@redhat.com, andrew+netdev@lunn.ch, horms@kernel.org, Jakub Kicinski , michael.chan@broadcom.com, daniel@iogearbox.net, hawk@kernel.org, john.fastabend@gmail.com, andrew.gospodarek@broadcom.com, pavan.chebbi@broadcom.com Subject: [PATCH net] eth: bnxt: always recalculate features after XDP clearing, fix null-deref Date: Wed, 8 Jan 2025 20:30:57 -0800 Message-ID: <20250109043057.2888953-1-kuba@kernel.org> X-Mailer: git-send-email 2.47.1 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: kuba@kernel.org Recalculate features when XDP is detached. Before: # ip li set dev eth0 xdp obj xdp_dummy.bpf.o sec xdp # ip li set dev eth0 xdp off # ethtool -k eth0 | grep gro rx-gro-hw: off [requested on] After: # ip li set dev eth0 xdp obj xdp_dummy.bpf.o sec xdp # ip li set dev eth0 xdp off # ethtool -k eth0 | grep gro rx-gro-hw: on The fact that HW-GRO doesn't get re-enabled automatically is just a minor annoyance. The real issue is that the features will randomly come back during another reconfiguration which just happens to invoke netdev_update_features(). The driver doesn't handle reconfiguring two things at a time very robustly. Starting with commit 98ba1d931f61 ("bnxt_en: Fix RSS logic in __bnxt_reserve_rings()") we only reconfigure the RSS hash table if the "effective" number of Rx rings has changed. If HW-GRO is enabled "effective" number of rings is 2x what user sees. So if we are in the bad state, with HW-GRO re-enablement "pending" after XDP off, and we lower the rings by / 2 - the HW-GRO rings doing 2x and the ethtool -L doing / 2 may cancel each other out, and the: if (old_rx_rings != bp->hw_resc.resv_rx_rings && condition in __bnxt_reserve_rings() will be false. The RSS map won't get updated, and we'll crash with: BUG: kernel NULL pointer dereference, address: 0000000000000168 RIP: 0010:__bnxt_hwrm_vnic_set_rss+0x13a/0x1a0 bnxt_hwrm_vnic_rss_cfg_p5+0x47/0x180 __bnxt_setup_vnic_p5+0x58/0x110 bnxt_init_nic+0xb72/0xf50 __bnxt_open_nic+0x40d/0xab0 bnxt_open_nic+0x2b/0x60 ethtool_set_channels+0x18c/0x1d0 As we try to access a freed ring. The issue is present since XDP support was added, really, but prior to commit 98ba1d931f61 ("bnxt_en: Fix RSS logic in __bnxt_reserve_rings()") it wasn't causing major issues. Fixes: 1054aee82321 ("bnxt_en: Use NETIF_F_GRO_HW.") Fixes: 98ba1d931f61 ("bnxt_en: Fix RSS logic in __bnxt_reserve_rings()") Signed-off-by: Jakub Kicinski Reviewed-by: Michael Chan Reviewed-by: Somnath Kotur --- CC: michael.chan@broadcom.com CC: daniel@iogearbox.net CC: hawk@kernel.org CC: john.fastabend@gmail.com CC: andrew.gospodarek@broadcom.com CC: pavan.chebbi@broadcom.com --- drivers/net/ethernet/broadcom/bnxt/bnxt.c | 25 +++++++++++++++---- drivers/net/ethernet/broadcom/bnxt/bnxt.h | 2 +- drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c | 7 ------ 3 files changed, 21 insertions(+), 13 deletions(-) diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c index aeaa74f03046..b6f844cac80e 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c @@ -4708,7 +4708,7 @@ void bnxt_set_ring_params(struct bnxt *bp) /* Changing allocation mode of RX rings. * TODO: Update when extending xdp_rxq_info to support allocation modes. */ -int bnxt_set_rx_skb_mode(struct bnxt *bp, bool page_mode) +static void __bnxt_set_rx_skb_mode(struct bnxt *bp, bool page_mode) { struct net_device *dev = bp->dev; @@ -4729,15 +4729,30 @@ int bnxt_set_rx_skb_mode(struct bnxt *bp, bool page_mode) bp->rx_skb_func = bnxt_rx_page_skb; } bp->rx_dir = DMA_BIDIRECTIONAL; - /* Disable LRO or GRO_HW */ - netdev_update_features(dev); } else { dev->max_mtu = bp->max_mtu; bp->flags &= ~BNXT_FLAG_RX_PAGE_MODE; bp->rx_dir = DMA_FROM_DEVICE; bp->rx_skb_func = bnxt_rx_skb; } - return 0; +} + +void bnxt_set_rx_skb_mode(struct bnxt *bp, bool page_mode) +{ + __bnxt_set_rx_skb_mode(bp, page_mode); + + if (!page_mode) { + int rx, tx; + + bnxt_get_max_rings(bp, &rx, &tx, true); + if (rx > 1) { + bp->flags &= ~BNXT_FLAG_NO_AGG_RINGS; + bp->dev->hw_features |= NETIF_F_LRO; + } + } + + /* Update LRO and GRO_HW availability */ + netdev_update_features(bp->dev); } static void bnxt_free_vnic_attributes(struct bnxt *bp) @@ -16214,7 +16229,7 @@ static int bnxt_init_one(struct pci_dev *pdev, const struct pci_device_id *ent) if (bp->max_fltr < BNXT_MAX_FLTR) bp->max_fltr = BNXT_MAX_FLTR; bnxt_init_l2_fltr_tbl(bp); - bnxt_set_rx_skb_mode(bp, false); + __bnxt_set_rx_skb_mode(bp, false); bnxt_set_tpa_flags(bp); bnxt_set_ring_params(bp); bnxt_rdma_aux_device_init(bp); diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.h b/drivers/net/ethernet/broadcom/bnxt/bnxt.h index 7df7a2233307..f11ed59203d9 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.h +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.h @@ -2846,7 +2846,7 @@ u32 bnxt_fw_health_readl(struct bnxt *bp, int reg_idx); bool bnxt_bs_trace_avail(struct bnxt *bp, u16 type); void bnxt_set_tpa_flags(struct bnxt *bp); void bnxt_set_ring_params(struct bnxt *); -int bnxt_set_rx_skb_mode(struct bnxt *bp, bool page_mode); +void bnxt_set_rx_skb_mode(struct bnxt *bp, bool page_mode); void bnxt_insert_usr_fltr(struct bnxt *bp, struct bnxt_filter_base *fltr); void bnxt_del_one_usr_fltr(struct bnxt *bp, struct bnxt_filter_base *fltr); int bnxt_hwrm_func_drv_rgtr(struct bnxt *bp, unsigned long *bmap, diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c index f88b641533fc..dc51dce209d5 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c @@ -422,15 +422,8 @@ static int bnxt_xdp_set(struct bnxt *bp, struct bpf_prog *prog) bnxt_set_rx_skb_mode(bp, true); xdp_features_set_redirect_target(dev, true); } else { - int rx, tx; - xdp_features_clear_redirect_target(dev); bnxt_set_rx_skb_mode(bp, false); - bnxt_get_max_rings(bp, &rx, &tx, true); - if (rx > 1) { - bp->flags &= ~BNXT_FLAG_NO_AGG_RINGS; - bp->dev->hw_features |= NETIF_F_LRO; - } } bp->tx_nr_rings_xdp = tx_xdp; bp->tx_nr_rings = bp->tx_nr_rings_per_tc * tc + tx_xdp;