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 CD2D62D543C; Wed, 11 Jun 2025 08:46:35 +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=1749631597; cv=none; b=KGD1mwea/5Fv4VQQ+I8CBw6f2wk3Lx663E7kaOzes14HVEZCaJ9yxL3dutdUyV2QCnQB8zpgmNQikMprmswkqGlYmDXBxsXvGVV9LGOHR/EdEPp90qR5r9rI+sekVIluGmqsgVoX2zDj0RiT2r2VbXfk8DG3ApPHgwZJN9wNbxs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749631597; c=relaxed/simple; bh=g2DXMg5rmDnhugpiHMmf1QfeOmclMqtPIujzWBitXX8=; h=From:To:Subject:Date:Message-Id:In-Reply-To:References; b=LayuUdDlQ8pM/s+7cU0w1q7GhFnkBalTkDhwlq4vaKCsVkHdqqqw/U7MoZBfaMxcTfjTgeHNrvVeUJprPUAvDwWKumiMNK6fHkxTOIwhANwG2+svPgbfjh+MmEgN5HBu9cCMX915ct++WbzjVyfv7mBgfpaVF7saAXue4eJXEmM= 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=f5kdgpoE; 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="f5kdgpoE" Received: by linux.microsoft.com (Postfix, from userid 1173) id 832F22115189; Wed, 11 Jun 2025 01:46:35 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 832F22115189 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1749631595; bh=r+GqLCuBE+ClBIUMKxQZzaAOal17+iAyuCgNMG8+Nm0=; h=From:To:Subject:Date:In-Reply-To:References:From; b=f5kdgpoEK3sZJT0i3w+IW0E99j79V2CPaRqZXhQndQH38n1bdsQrTfXaB/pHbFzvP he0ZO8kEn1vSm0LaMm+Cld4Qw1mvbgu0HQ2G1kTiAgo+BiEcJzO8qk9c5IW29JRbXa 78/rwrfx36XOg2ZY+d+Eq10kI5mQQXXAgD14F5OA= 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, kotaranov@microsoft.com, longli@microsoft.com, horms@kernel.org, shirazsaleem@microsoft.com, leon@kernel.org, ernis@linux.microsoft.com, shradhagupta@linux.microsoft.com, schakrabarti@linux.microsoft.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 1/4] net: mana: Fix potential deadlocks in mana napi ops Date: Wed, 11 Jun 2025 01:46:13 -0700 Message-Id: <1749631576-2517-2-git-send-email-ernis@linux.microsoft.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1749631576-2517-1-git-send-email-ernis@linux.microsoft.com> References: <1749631576-2517-1-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. The netvsc sets up MANA VF via following call chain: netvsc_vf_setup() dev_change_flags() ... __dev_open() OR __dev_close() dev_change_flags() holds the netdev mutex via netdev_lock_ops. During this process, mana_create_txq() and mana_create_rxq() invoke netif_napi_add_tx(), netif_napi_add_weight(), and napi_enable(), all of which attempt to acquire the same lock, leading to a potential deadlock. Similarly, mana_destroy_txq() and mana_destroy_rxq() call netif_napi_disable() and netif_napi_del(), which also 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 --- drivers/net/ethernet/microsoft/mana/mana_en.c | 39 ++++++++++++++----- 1 file changed, 30 insertions(+), 9 deletions(-) diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c index ccd2885c939e..3c879d8a39e3 100644 --- a/drivers/net/ethernet/microsoft/mana/mana_en.c +++ b/drivers/net/ethernet/microsoft/mana/mana_en.c @@ -1911,8 +1911,13 @@ 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); + if (netdev_need_ops_lock(napi->dev)) { + napi_disable_locked(napi); + netif_napi_del_locked(napi); + } else { + napi_disable(napi); + netif_napi_del(napi); + } apc->tx_qp[i].txq.napi_initialized = false; } mana_destroy_wq_obj(apc, GDMA_SQ, apc->tx_qp[i].tx_object); @@ -2064,8 +2069,14 @@ 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); + if (netdev_need_ops_lock(net)) { + set_bit(NAPI_STATE_NO_BUSY_POLL, &cq->napi.state); + netif_napi_add_locked(net, &cq->napi, mana_poll); + napi_enable_locked(&cq->napi); + } else { + netif_napi_add_tx(net, &cq->napi, mana_poll); + napi_enable(&cq->napi); + } txq->napi_initialized = true; mana_gd_ring_cq(cq->gdma_cq, SET_ARM_BIT); @@ -2101,9 +2112,13 @@ static void mana_destroy_rxq(struct mana_port_context *apc, if (napi_initialized) { napi_synchronize(napi); - napi_disable(napi); - - netif_napi_del(napi); + if (netdev_need_ops_lock(napi->dev)) { + napi_disable_locked(napi); + netif_napi_del_locked(napi); + } else { + napi_disable(napi); + netif_napi_del(napi); + } } xdp_rxq_info_unreg(&rxq->xdp_rxq); @@ -2354,14 +2369,20 @@ 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); + if (netdev_need_ops_lock(ndev)) + netif_napi_add_weight_locked(ndev, &cq->napi, mana_poll, 1); + else + netif_napi_add_weight(ndev, &cq->napi, mana_poll, 1); 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); + if (netdev_need_ops_lock(ndev)) + napi_enable_locked(&cq->napi); + else + napi_enable(&cq->napi); mana_gd_ring_cq(cq->gdma_cq, SET_ARM_BIT); out: -- 2.34.1