From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id A60E52D540C; Fri, 13 Jun 2025 11:20:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749813632; cv=none; b=E3eSyEw6Fr9op1bX5wNQHIRFbQ5yTzmpIU0h5PL2jVugRJGdC6nGn0PHkmDKMEwyCabQ3nT3bN9q2LmeT9GqptxxNk2s+4j1zwoMRXaRnMwqDFiUFNsa1LaLtWKBs6ioyqPmfP+7PdG9zjjt3kNfHhteZL7RtECYvxrjfqjXvVY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749813632; c=relaxed/simple; bh=T8M8l/OSfqF6LAD2opiryZllIbiWH12cgjvJos95K/A=; h=From:To:Subject:Date:Message-Id:In-Reply-To:References; b=YYOxnP05Q1jpux4uYBBqSAeKcXO4PyhSxKaA7w8ljI28DLZccLckYnaz7I9k4FOwDGdceBH4ZGrSBi4dPn6oHcPNHt+Su+YkObEdDJ4eCoxgbxOAw/m0zwKfSrkfMNKyGvqaZooqU/FC38qMU3J18edGd1BHx+XkYrxt4HveziM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=rcj58bYi; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="rcj58bYi" Received: by linux.microsoft.com (Postfix, from userid 1173) id 43663201C775; Fri, 13 Jun 2025 04:20:30 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 43663201C775 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1749813630; bh=cP2o3EuJ+p3R1t0enkJckW1hpdqJe16ROT2UBloMEak=; h=From:To:Subject:Date:In-Reply-To:References:From; b=rcj58bYikfHixGsadDstumxnYOpQ2cczgQ3tPbZwypPNycE6iiYQASD14+rtR5Wxq 1INnpJ4W3DvFB4MjF9rkd6z4E3lQJlUfrhTkPAkViR8/nDALW7FoN/fnnsuUZaYGVJ fCtUEwxNuq+aG/kxvnMEMUBJs4AfjzPvpf5xXjIY= From: Erni Sri Satya Vennela To: kys@microsoft.com, haiyangz@microsoft.com, wei.liu@kernel.org, decui@microsoft.com, andrew+netdev@lunn.ch, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, longli@microsoft.com, kotaranov@microsoft.com, horms@kernel.org, shirazsaleem@microsoft.com, leon@kernel.org, ernis@linux.microsoft.com, shradhagupta@linux.microsoft.com, schakrabarti@linux.microsoft.com, gerhard@engleder-embedded.com, rosenp@gmail.com, sdf@fomichev.me, linux-hyperv@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org Subject: [PATCH net-next v2 1/4] net: mana: Fix potential deadlocks in mana napi ops Date: Fri, 13 Jun 2025 04:20:24 -0700 Message-Id: <1749813627-8377-2-git-send-email-ernis@linux.microsoft.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1749813627-8377-1-git-send-email-ernis@linux.microsoft.com> References: <1749813627-8377-1-git-send-email-ernis@linux.microsoft.com> Precedence: bulk X-Mailing-List: linux-rdma@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: When net_shaper_ops are enabled for MANA, netdev_ops_lock becomes active. MANA VF setup/teardown by netvsc follows this call chain: netvsc_vf_setup() dev_change_flags() ... __dev_open() OR __dev_close() dev_change_flags() holds the netdev mutex via netdev_lock_ops. Meanwhile, mana_create_txq() and mana_create_rxq() in mana_open() path call NAPI APIs (netif_napi_add_tx(), netif_napi_add_weight(), napi_enable()), which also try to acquire the same lock, risking deadlock. Similarly in the teardown path (mana_close()), netif_napi_disable() and netif_napi_del(), contend for the same lock. Switch to the _locked variants of these APIs to avoid deadlocks when the netdev_ops_lock is held. Fixes: d4c22ec680c8 ("net: hold netdev instance lock during ndo_open/ndo_stop") Signed-off-by: Erni Sri Satya Vennela Reviewed-by: Haiyang Zhang Reviewed-by: Shradha Gupta Reviewed-by: Saurabh Singh Sengar --- Changes in v2: * Use netdev_lock_ops_to_full() instead of if...else statements for napi APIs. * Edit commit message. --- drivers/net/ethernet/microsoft/mana/mana_en.c | 30 +++++++++++++------ 1 file changed, 21 insertions(+), 9 deletions(-) diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c index e68b8190bb7a..ca5e9c3d374b 100644 --- a/drivers/net/ethernet/microsoft/mana/mana_en.c +++ b/drivers/net/ethernet/microsoft/mana/mana_en.c @@ -1912,8 +1912,11 @@ static void mana_destroy_txq(struct mana_port_context *apc) napi = &apc->tx_qp[i].tx_cq.napi; if (apc->tx_qp[i].txq.napi_initialized) { napi_synchronize(napi); - napi_disable(napi); - netif_napi_del(napi); + netdev_lock_ops_to_full(napi->dev); + napi_disable_locked(napi); + netif_napi_del_locked(napi); + netdev_unlock_full_to_ops(napi->dev); apc->tx_qp[i].txq.napi_initialized = false; } mana_destroy_wq_obj(apc, GDMA_SQ, apc->tx_qp[i].tx_object); @@ -2065,8 +2068,11 @@ static int mana_create_txq(struct mana_port_context *apc, mana_create_txq_debugfs(apc, i); - netif_napi_add_tx(net, &cq->napi, mana_poll); - napi_enable(&cq->napi); + set_bit(NAPI_STATE_NO_BUSY_POLL, &cq->napi.state); + netdev_lock_ops_to_full(net); + netif_napi_add_locked(net, &cq->napi, mana_poll); + napi_enable_locked(&cq->napi); + netdev_unlock_full_to_ops(net); txq->napi_initialized = true; mana_gd_ring_cq(cq->gdma_cq, SET_ARM_BIT); @@ -2102,9 +2108,11 @@ static void mana_destroy_rxq(struct mana_port_context *apc, if (napi_initialized) { napi_synchronize(napi); - napi_disable(napi); - - netif_napi_del(napi); + netdev_lock_ops_to_full(napi->dev); + napi_disable_locked(napi); + netif_napi_del_locked(napi); + netdev_unlock_full_to_ops(napi->dev); } xdp_rxq_info_unreg(&rxq->xdp_rxq); @@ -2355,14 +2363,18 @@ static struct mana_rxq *mana_create_rxq(struct mana_port_context *apc, gc->cq_table[cq->gdma_id] = cq->gdma_cq; - netif_napi_add_weight(ndev, &cq->napi, mana_poll, 1); + netdev_lock_ops_to_full(ndev); + netif_napi_add_weight_locked(ndev, &cq->napi, mana_poll, 1); + netdev_unlock_full_to_ops(ndev); WARN_ON(xdp_rxq_info_reg(&rxq->xdp_rxq, ndev, rxq_idx, cq->napi.napi_id)); WARN_ON(xdp_rxq_info_reg_mem_model(&rxq->xdp_rxq, MEM_TYPE_PAGE_POOL, rxq->page_pool)); - napi_enable(&cq->napi); + netdev_lock_ops_to_full(ndev); + napi_enable_locked(&cq->napi); + netdev_unlock_full_to_ops(ndev); mana_gd_ring_cq(cq->gdma_cq, SET_ARM_BIT); out: -- 2.34.1