From patchwork Tue Feb 4 23:00:54 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stanislav Fomichev X-Patchwork-Id: 13960144 X-Patchwork-Delegate: kuba@kernel.org Received: from mail-pl1-f176.google.com (mail-pl1-f176.google.com [209.85.214.176]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 34208206F16 for ; Tue, 4 Feb 2025 23:01:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.176 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738710063; cv=none; b=aazxlqq9dLDGoQddGTxk9h117MIomVWONvobptQI79nqrn5f9b93xhOS1G6E3xorxHHhV422LPt9gg6tyrLi1NYZrxyTvqZFayG+hF5aPpGVm3x5hGWzewzHA2wLt58t7wdiPuvMHNeZh0EZFSw/vkxRBh/tM8bYFkf0fDEzeE0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738710063; c=relaxed/simple; bh=r4pLZP27SnGk+NUHU8GerlNYnqnEDtaakLxWmssmaXg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=CeebNc3BBHHOsUqSCQ5oNHF2FmHrtTSG3Wga4LVqcwTvYB3JZTiD9AzP40uI9RMETcbxxsVKEMPLH0yTfjSVNmRWqHPEEdolzTB/+e/kHj2eLJ9bu0qJvCaYGW/OrBXbdk6A9JAYH+X4Wf0hOx8B+9E452tW/D4q0D7NdAVJUXg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=fomichev.me; spf=pass smtp.mailfrom=gmail.com; arc=none smtp.client-ip=209.85.214.176 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=fomichev.me Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-pl1-f176.google.com with SMTP id d9443c01a7336-2163dc5155fso108573235ad.0 for ; Tue, 04 Feb 2025 15:01:00 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1738710060; x=1739314860; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=ElQb9U4uQw6ven++d30UUeDXa84HifTkFMszzPFiP4M=; b=lSYC/NZpsAtpUExgiwQ5N1UV96tlZ1n8kA4VX7KHxmx/UeFVVRZilnSU+XEBkYKxIw uuKUZYhxxkgxXKdKHawAAIh9z5ofecMRQ/b15aTT7NFvx7buamue6OM2lWXy5rKWX7EK QGQlAXP04xsA8eZnvI+g6iQ8lVvGmZxjArEtd8fuIHbb3CgMunaRFZKJu9/TEfBMsTY6 OtRXBI/eki5SaCC/PUgM0aUUi1Cc3eQAV3S/xPN8JfriVcoM4IO59P0xVvKX7h2vQfnF ZRuqBgcLFb6lvr45MRMvriXvi0OnsOvdLxqabT762Hp/gPu5lb+XHWBGf7vMbSlQrdQg TFVg== X-Gm-Message-State: AOJu0Yxmpy+/Z9ISnnXESrACgcr61b1mZlpszUgV04HxuZCQqZr8jaUX h8TLLXJVMUF2wr3lBA8FEbwpS+ZsGurrfCrQDb9j4+JSGHgqz4u2n5wn X-Gm-Gg: ASbGncv1hHOoCqqPgSnMBJj20qrvOu0DIfBzLbLuNnwk7tXgQehTCJ8c1YhYr8+Khjl pEpa0/HlGdLZDiuD+wmqd+8zPjOh7NkCl2yYMU9XR413mLIuLXOgIBZ99arK1th6icQtPOpgq8W TWsq55SBhhUjYdpcpZQH/gfk52MASFeHvHPGoFimQj4UR2CApc83eabtnTG9aV7sab2vxW5/p5p tr++aAxvML/pPjXnJvRKXWgkmgPP+n4cBgbrqbxRceHbm6PvpzgTjg0vp0joAxVK75t9EdqWJGl RsF8U6bX3xXM2sY= X-Google-Smtp-Source: AGHT+IEmOnfAJ9my4yJ3mm8rM7h5TDMuOxxQs5p8g6UUpb/82MJzF1bynncwi1SDlIZ2wtNL2ZNmIg== X-Received: by 2002:a05:6a00:28cc:b0:725:f1b1:cbc5 with SMTP id d2e1a72fcca58-730350f96demr1316232b3a.3.1738710059931; Tue, 04 Feb 2025 15:00:59 -0800 (PST) Received: from localhost ([2601:646:9e00:f56e:123b:cea3:439a:b3e3]) by smtp.gmail.com with UTF8SMTPSA id 41be03b00d2f7-acebe384272sm9110022a12.18.2025.02.04.15.00.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 04 Feb 2025 15:00:59 -0800 (PST) From: Stanislav Fomichev To: netdev@vger.kernel.org Cc: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, Saeed Mahameed Subject: [RFC net-next 1/4] net: Hold netdev instance lock during ndo_open/ndo_stop Date: Tue, 4 Feb 2025 15:00:54 -0800 Message-ID: <20250204230057.1270362-2-sdf@fomichev.me> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250204230057.1270362-1-sdf@fomichev.me> References: <20250204230057.1270362-1-sdf@fomichev.me> 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 X-Patchwork-State: RFC For the drivers that use shaper API, switch to the mode where core stack holds the netdev lock. This affects two drivers: * iavf - already grabs netdev lock in ndo_open/ndo_stop, so mostly remove these * netdevsim - switch to _locked APIs to avoid deadlock Cc: Saeed Mahameed Signed-off-by: Stanislav Fomichev --- Documentation/networking/netdevices.rst | 6 ++++-- drivers/net/ethernet/intel/iavf/iavf_main.c | 14 ++++++------- drivers/net/netdevsim/netdev.c | 14 ++++++++----- include/linux/netdevice.h | 23 +++++++++++++++++++++ net/core/dev.c | 12 +++++++++++ net/core/dev.h | 6 ++++-- 6 files changed, 58 insertions(+), 17 deletions(-) diff --git a/Documentation/networking/netdevices.rst b/Documentation/networking/netdevices.rst index 1d37038e9fbe..78213e476ce6 100644 --- a/Documentation/networking/netdevices.rst +++ b/Documentation/networking/netdevices.rst @@ -210,11 +210,13 @@ packets is preferred. struct net_device synchronization rules ======================================= ndo_open: - Synchronization: rtnl_lock() semaphore. + Synchronization: rtnl_lock() semaphore. In addition, netdev instance + lock if the driver implements shaper API. Context: process ndo_stop: - Synchronization: rtnl_lock() semaphore. + Synchronization: rtnl_lock() semaphore. In addition, netdev instance + lock if the driver implements shaper API. Context: process Note: netif_running() is guaranteed false diff --git a/drivers/net/ethernet/intel/iavf/iavf_main.c b/drivers/net/ethernet/intel/iavf/iavf_main.c index 2d7a18fcc3be..176f9bb871d0 100644 --- a/drivers/net/ethernet/intel/iavf/iavf_main.c +++ b/drivers/net/ethernet/intel/iavf/iavf_main.c @@ -4375,22 +4375,21 @@ static int iavf_open(struct net_device *netdev) struct iavf_adapter *adapter = netdev_priv(netdev); int err; + netdev_assert_locked(netdev); + if (adapter->flags & IAVF_FLAG_PF_COMMS_FAILED) { dev_err(&adapter->pdev->dev, "Unable to open device due to PF driver failure.\n"); return -EIO; } - netdev_lock(netdev); while (!mutex_trylock(&adapter->crit_lock)) { /* If we are in __IAVF_INIT_CONFIG_ADAPTER state the crit_lock * is already taken and iavf_open is called from an upper * device's notifier reacting on NETDEV_REGISTER event. * We have to leave here to avoid dead lock. */ - if (adapter->state == __IAVF_INIT_CONFIG_ADAPTER) { - netdev_unlock(netdev); + if (adapter->state == __IAVF_INIT_CONFIG_ADAPTER) return -EBUSY; - } usleep_range(500, 1000); } @@ -4439,7 +4438,6 @@ static int iavf_open(struct net_device *netdev) iavf_irq_enable(adapter, true); mutex_unlock(&adapter->crit_lock); - netdev_unlock(netdev); return 0; @@ -4452,7 +4450,6 @@ static int iavf_open(struct net_device *netdev) iavf_free_all_tx_resources(adapter); err_unlock: mutex_unlock(&adapter->crit_lock); - netdev_unlock(netdev); return err; } @@ -4474,12 +4471,12 @@ static int iavf_close(struct net_device *netdev) u64 aq_to_restore; int status; - netdev_lock(netdev); + netdev_assert_locked(netdev); + mutex_lock(&adapter->crit_lock); if (adapter->state <= __IAVF_DOWN_PENDING) { mutex_unlock(&adapter->crit_lock); - netdev_unlock(netdev); return 0; } @@ -4532,6 +4529,7 @@ static int iavf_close(struct net_device *netdev) if (!status) netdev_warn(netdev, "Device resources not yet released\n"); + netdev_lock(netdev); mutex_lock(&adapter->crit_lock); adapter->aq_required |= aq_to_restore; mutex_unlock(&adapter->crit_lock); diff --git a/drivers/net/netdevsim/netdev.c b/drivers/net/netdevsim/netdev.c index 42f247cbdcee..efec03b34c9f 100644 --- a/drivers/net/netdevsim/netdev.c +++ b/drivers/net/netdevsim/netdev.c @@ -401,7 +401,7 @@ static int nsim_init_napi(struct netdevsim *ns) for (i = 0; i < dev->num_rx_queues; i++) { rq = ns->rq[i]; - netif_napi_add_config(dev, &rq->napi, nsim_poll, i); + netif_napi_add_config_locked(dev, &rq->napi, nsim_poll, i); } for (i = 0; i < dev->num_rx_queues; i++) { @@ -421,7 +421,7 @@ static int nsim_init_napi(struct netdevsim *ns) } for (i = 0; i < dev->num_rx_queues; i++) - __netif_napi_del(&ns->rq[i]->napi); + __netif_napi_del_locked(&ns->rq[i]->napi); return err; } @@ -435,7 +435,7 @@ static void nsim_enable_napi(struct netdevsim *ns) struct nsim_rq *rq = ns->rq[i]; netif_queue_set_napi(dev, i, NETDEV_QUEUE_TYPE_RX, &rq->napi); - napi_enable(&rq->napi); + napi_enable_locked(&rq->napi); } } @@ -444,6 +444,8 @@ static int nsim_open(struct net_device *dev) struct netdevsim *ns = netdev_priv(dev); int err; + netdev_assert_locked(dev); + err = nsim_init_napi(ns); if (err) return err; @@ -461,8 +463,8 @@ static void nsim_del_napi(struct netdevsim *ns) for (i = 0; i < dev->num_rx_queues; i++) { struct nsim_rq *rq = ns->rq[i]; - napi_disable(&rq->napi); - __netif_napi_del(&rq->napi); + napi_disable_locked(&rq->napi); + __netif_napi_del_locked(&rq->napi); } synchronize_net(); @@ -477,6 +479,8 @@ static int nsim_stop(struct net_device *dev) struct netdevsim *ns = netdev_priv(dev); struct netdevsim *peer; + netdev_assert_locked(dev); + netif_carrier_off(dev); peer = rtnl_dereference(ns->peer); if (peer) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 2a59034a5fa2..962774cbce55 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -2717,6 +2717,29 @@ static inline void netdev_assert_locked_or_invisible(struct net_device *dev) netdev_assert_locked(dev); } +static inline bool need_netdev_ops_lock(struct net_device *dev) +{ + bool ret = false; + +#if IS_ENABLED(CONFIG_NET_SHAPER) + ret |= !!(dev)->netdev_ops->net_shaper_ops; +#endif + + return ret; +} + +static inline void netdev_lock_ops(struct net_device *dev) +{ + if (need_netdev_ops_lock(dev)) + netdev_lock(dev); +} + +static inline void netdev_unlock_ops(struct net_device *dev) +{ + if (need_netdev_ops_lock(dev)) + netdev_unlock(dev); +} + static inline void netif_napi_set_irq_locked(struct napi_struct *napi, int irq) { napi->irq = irq; diff --git a/net/core/dev.c b/net/core/dev.c index c0021cbd28fc..fda42b2415fc 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1595,6 +1595,8 @@ static int __dev_open(struct net_device *dev, struct netlink_ext_ack *extack) if (ret) return ret; + netdev_lock_ops(dev); + set_bit(__LINK_STATE_START, &dev->state); if (ops->ndo_validate_addr) @@ -1614,6 +1616,8 @@ static int __dev_open(struct net_device *dev, struct netlink_ext_ack *extack) add_device_randomness(dev->dev_addr, dev->addr_len); } + netdev_unlock_ops(dev); + return ret; } @@ -1684,11 +1688,19 @@ static void __dev_close_many(struct list_head *head) * We allow it to be called even after a DETACH hot-plug * event. */ + + /* TODO: move the lock up before clearing __LINK_STATE_START. + * Generates spurious lockdep warning. + */ + netdev_lock_ops(dev); + if (ops->ndo_stop) ops->ndo_stop(dev); netif_set_up(dev, false); netpoll_poll_enable(dev); + + netdev_unlock_ops(dev); } } diff --git a/net/core/dev.h b/net/core/dev.h index a5b166bbd169..18070c0452e3 100644 --- a/net/core/dev.h +++ b/net/core/dev.h @@ -134,9 +134,11 @@ static inline void netif_set_up(struct net_device *dev, bool value) else dev->flags &= ~IFF_UP; - netdev_lock(dev); + if (!need_netdev_ops_lock(dev)) + netdev_lock(dev); dev->up = value; - netdev_unlock(dev); + if (!need_netdev_ops_lock(dev)) + netdev_unlock(dev); } static inline void netif_set_gso_max_size(struct net_device *dev,