From patchwork Wed Mar 5 16:37:29 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stanislav Fomichev X-Patchwork-Id: 14002995 X-Patchwork-Delegate: kuba@kernel.org Received: from mail-pl1-f179.google.com (mail-pl1-f179.google.com [209.85.214.179]) (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 658101A83E7 for ; Wed, 5 Mar 2025 16:37:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.179 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741192670; cv=none; b=Qdr0PNYlFEQjXPXiGNIWEai4uqMQrolax3CBDDb1H0SmkRzUmc8+IeQ23wWMKJhimXAcS+mwG5gJasMCnjPnXMMFthkBIn78L1XqC7mlpR3mF2xfClfIGhbMNTXbwAWcp2gnkOqDAPhvI9Ha5CXE15//q87yxY3YYHzJqaemTGA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741192670; c=relaxed/simple; bh=a/3RxdPc5gnV9hS+ng2ca1x/sFXB6m7XFaWWWZh3dOQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Yf3KdIEyhw1XeCrgAdo8tVmi4iSrjdY+NNDzA0XMPIOuHwY51xe6+zyHne3aUGaSfjXs1TEUa3Wgo6EUZN6W6BBrdVGE1Vt4uq5AJHr1XKdZpqkbyn+2uEV3N2VS3DYPxtec64cwRxfLj2fpdzOAfvA7xmxfwYCsRygZd/zHH+A= 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=209.85.214.179 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-f179.google.com with SMTP id d9443c01a7336-223594b3c6dso124356725ad.2 for ; Wed, 05 Mar 2025 08:37:48 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1741192667; x=1741797467; 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=yfWTvWbyDq1kenQETtci1B2urSM+ldhyN3/5m4ksPmc=; b=akMLRs3dQ6E5hjoC+OThVdpQrL5Dwa2FoYk/ya/ddZxAQbE7u6BzP8Hx+xPISWeTR5 hX4s1wEpQVEajnxG6dVVr10wPRVd9DIgMF8sWLNF91RqoexAV1X9KNXi7xzb2N/9Pn77 adXON0gZkWn/vECV3tgvU5g8ibJEmL1NnAgLvjHk79R3b1xvfKOOMXAWiC0gCfX9jpT9 5k0Jj63aAhBL+OjrEmfoGYSUlvNI4RJ/yBvnO8TT2T4QIJt2eec0+7QAiWynOcpQzbX7 R3+m2GkwXiolXVrWevPpqLzRAkIdR4msnTk1cZnf2YZaAclOjWfDTkJNG6sC9TBYL6on PKyA== X-Gm-Message-State: AOJu0YyQApd+Ag2JtD6AgFAfA8qtsF4INMz+vBP1G8bcIDfeco9LvKTg ElwwwbpkOL6gqUtfgQ5R0KDaESH7LYRYjEgi4i5mqL71JCQrih1rYfHa X-Gm-Gg: ASbGncvuUmBYf9W1XQcCZWNvL5WPthWeBPgmHA98jEpV5RbDgCGIuMtvmpS4xZHcnPL Mt/J4TJiiODxo8jEJ7t8cX5Az9NY7q7SNlyfsxf/IaYXn32/ylxV8qNqZLR4BQ8gTmejDhDEupA e02Lb/fpOeAkLssf1vmnk5ZmWJg0Aepb35hoOoj3f4OJdbLzX85489Cmjq17Gl9+zxuaJnM0+io ALr+9b32klWkNdAP39Ucyg0eDZugFky8IoE7fX9MGTSO+OVnRed7evh/9huslf4ySSdBiopaKwb +8CBfIp1m5xaqnBGYVac/SebTBeWOM6/P8Ji1T9argpn X-Google-Smtp-Source: AGHT+IF0eaPWZTX6tsDVUO4MX4gdT5nhsvMhSYEwZA0ILL414KIwFRn4SUu1M2m/1IEuztURI8SAQA== X-Received: by 2002:a17:903:19e5:b0:223:5c8e:b753 with SMTP id d9443c01a7336-223f1d83cacmr59048705ad.50.1741192667460; Wed, 05 Mar 2025 08:37:47 -0800 (PST) Received: from localhost ([2601:646:9e00:f56e:2844:3d8f:bf3e:12cc]) by smtp.gmail.com with UTF8SMTPSA id d2e1a72fcca58-7364b4eff66sm7069631b3a.83.2025.03.05.08.37.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 05 Mar 2025 08:37:47 -0800 (PST) From: Stanislav Fomichev To: netdev@vger.kernel.org Cc: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com Subject: [PATCH net-next v10 11/14] net: replace dev_addr_sem with netdev instance lock Date: Wed, 5 Mar 2025 08:37:29 -0800 Message-ID: <20250305163732.2766420-12-sdf@fomichev.me> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250305163732.2766420-1-sdf@fomichev.me> References: <20250305163732.2766420-1-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 Lockdep reports possible circular dependency in [0]. Instead of fixing the ordering, replace global dev_addr_sem with netdev instance lock. Most of the paths that set/get mac are RTNL protected. Two places where it's not, convert to explicit locking: - sysfs address_show - dev_get_mac_address via dev_ioctl 0: https://netdev-3.bots.linux.dev/vmksft-forwarding-dbg/results/993321/24-router-bridge-1d-lag-sh/stderr Signed-off-by: Stanislav Fomichev --- drivers/net/tap.c | 2 +- drivers/net/tun.c | 2 +- include/linux/netdevice.h | 6 +---- net/core/dev.c | 52 ++++++++++++++++++++------------------- net/core/dev.h | 3 +-- net/core/dev_api.c | 17 ++----------- net/core/dev_ioctl.c | 2 +- net/core/net-sysfs.c | 7 ++---- net/core/rtnetlink.c | 6 ++++- 9 files changed, 41 insertions(+), 56 deletions(-) diff --git a/drivers/net/tap.c b/drivers/net/tap.c index d4ece538f1b2..4382f5e323b0 100644 --- a/drivers/net/tap.c +++ b/drivers/net/tap.c @@ -1017,7 +1017,7 @@ static long tap_ioctl(struct file *file, unsigned int cmd, rtnl_unlock(); return -ENOLINK; } - ret = dev_set_mac_address_user(tap->dev, &sa, NULL); + ret = dev_set_mac_address(tap->dev, &sa, NULL); tap_put_tap_dev(tap); rtnl_unlock(); return ret; diff --git a/drivers/net/tun.c b/drivers/net/tun.c index d8f4d3e996a7..1e645d5e225c 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -3175,7 +3175,7 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd, case SIOCSIFHWADDR: /* Set hw address */ - ret = dev_set_mac_address_user(tun->dev, &ifr.ifr_hwaddr, NULL); + ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr, NULL); break; case TUNGETSNDBUF: diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index ca9c09dab14e..f3e6e6f27e22 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -2492,7 +2492,7 @@ struct net_device { * * Protects: * @gro_flush_timeout, @napi_defer_hard_irqs, @napi_list, - * @net_shaper_hierarchy, @reg_state, @threaded + * @net_shaper_hierarchy, @reg_state, @threaded, @dev_addr * * Partially protects (writers must hold both @lock and rtnl_lock): * @up @@ -4262,10 +4262,6 @@ int netif_set_mac_address(struct net_device *dev, struct sockaddr *sa, struct netlink_ext_ack *extack); int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa, struct netlink_ext_ack *extack); -int netif_set_mac_address_user(struct net_device *dev, struct sockaddr *sa, - struct netlink_ext_ack *extack); -int dev_set_mac_address_user(struct net_device *dev, struct sockaddr *sa, - struct netlink_ext_ack *extack); int dev_get_mac_address(struct sockaddr *sa, struct net *net, char *dev_name); int dev_get_port_parent_id(struct net_device *dev, struct netdev_phys_item_id *ppid, bool recurse); diff --git a/net/core/dev.c b/net/core/dev.c index 404047d4d943..a0f75a1d1f5a 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1058,6 +1058,28 @@ struct net_device *netdev_get_by_index_lock(struct net *net, int ifindex) return __netdev_put_lock(dev); } +/** + * netdev_get_by_name_lock() - find a device by its name + * @net: the applicable net namespace + * @name: name of device + * + * Search for an interface by name. If a valid device + * with @name is found it will be returned with netdev->lock held. + * netdev_unlock() must be called to release it. + * + * Return: pointer to a device with lock held, NULL if not found. + */ +struct net_device *netdev_get_by_name_lock(struct net *net, const char *name) +{ + struct net_device *dev; + + dev = dev_get_by_name(net, name); + if (!dev) + return NULL; + + return __netdev_put_lock(dev); +} + struct net_device * netdev_xa_find_lock(struct net *net, struct net_device *dev, unsigned long *index) @@ -9589,44 +9611,24 @@ int netif_set_mac_address(struct net_device *dev, struct sockaddr *sa, return 0; } -DECLARE_RWSEM(dev_addr_sem); - -int netif_set_mac_address_user(struct net_device *dev, struct sockaddr *sa, - struct netlink_ext_ack *extack) -{ - int ret; - - down_write(&dev_addr_sem); - ret = netif_set_mac_address(dev, sa, extack); - up_write(&dev_addr_sem); - return ret; -} - int dev_get_mac_address(struct sockaddr *sa, struct net *net, char *dev_name) { size_t size = sizeof(sa->sa_data_min); struct net_device *dev; - int ret = 0; - down_read(&dev_addr_sem); - rcu_read_lock(); + dev = netdev_get_by_name_lock(net, dev_name); + if (!dev) + return -ENODEV; - dev = dev_get_by_name_rcu(net, dev_name); - if (!dev) { - ret = -ENODEV; - goto unlock; - } if (!dev->addr_len) memset(sa->sa_data, 0, size); else memcpy(sa->sa_data, dev->dev_addr, min_t(size_t, size, dev->addr_len)); sa->sa_family = dev->type; + netdev_unlock(dev); -unlock: - rcu_read_unlock(); - up_read(&dev_addr_sem); - return ret; + return 0; } EXPORT_SYMBOL(dev_get_mac_address); diff --git a/net/core/dev.h b/net/core/dev.h index 41b0831aba60..b50ca645c086 100644 --- a/net/core/dev.h +++ b/net/core/dev.h @@ -28,6 +28,7 @@ netdev_napi_by_id_lock(struct net *net, unsigned int napi_id); struct net_device *dev_get_by_napi_id(unsigned int napi_id); struct net_device *netdev_get_by_index_lock(struct net *net, int ifindex); +struct net_device *netdev_get_by_name_lock(struct net *net, const char *name); struct net_device *__netdev_put_lock(struct net_device *dev); struct net_device * netdev_xa_find_lock(struct net *net, struct net_device *dev, @@ -69,8 +70,6 @@ extern int weight_p; extern int dev_weight_rx_bias; extern int dev_weight_tx_bias; -extern struct rw_semaphore dev_addr_sem; - /* rtnl helpers */ extern struct list_head net_todo_list; void netdev_run_todo(void); diff --git a/net/core/dev_api.c b/net/core/dev_api.c index 98db990ce21c..655a95fb7baa 100644 --- a/net/core/dev_api.c +++ b/net/core/dev_api.c @@ -82,19 +82,6 @@ void dev_set_group(struct net_device *dev, int new_group) netdev_unlock_ops(dev); } -int dev_set_mac_address_user(struct net_device *dev, struct sockaddr *sa, - struct netlink_ext_ack *extack) -{ - int ret; - - netdev_lock_ops(dev); - ret = netif_set_mac_address_user(dev, sa, extack); - netdev_unlock_ops(dev); - - return ret; -} -EXPORT_SYMBOL(dev_set_mac_address_user); - /** * dev_change_net_namespace() - move device to different nethost namespace * @dev: device @@ -310,9 +297,9 @@ int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa, { int ret; - netdev_lock_ops(dev); + netdev_lock(dev); ret = netif_set_mac_address(dev, sa, extack); - netdev_unlock_ops(dev); + netdev_unlock(dev); return ret; } diff --git a/net/core/dev_ioctl.c b/net/core/dev_ioctl.c index d9f350593121..296e52d1395d 100644 --- a/net/core/dev_ioctl.c +++ b/net/core/dev_ioctl.c @@ -574,7 +574,7 @@ static int dev_ifsioc(struct net *net, struct ifreq *ifr, void __user *data, case SIOCSIFHWADDR: if (dev->addr_len > sizeof(struct sockaddr)) return -EINVAL; - return dev_set_mac_address_user(dev, &ifr->ifr_hwaddr, NULL); + return dev_set_mac_address(dev, &ifr->ifr_hwaddr, NULL); case SIOCSIFHWBROADCAST: if (ifr->ifr_hwaddr.sa_family != dev->type) diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c index 27eea34d1b41..02d1d40b47ae 100644 --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -262,14 +262,11 @@ static ssize_t address_show(struct device *dev, struct device_attribute *attr, struct net_device *ndev = to_net_dev(dev); ssize_t ret = -EINVAL; - down_read(&dev_addr_sem); - - rcu_read_lock(); + netdev_lock(ndev); if (dev_isalive(ndev)) ret = sysfs_format_mac(buf, ndev->dev_addr, ndev->addr_len); - rcu_read_unlock(); + netdev_unlock(ndev); - up_read(&dev_addr_sem); return ret; } static DEVICE_ATTR_RO(address); diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 9d539c9ce1a4..88a352b02bce 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -3089,7 +3089,11 @@ static int do_setlink(const struct sk_buff *skb, struct net_device *dev, sa->sa_family = dev->type; memcpy(sa->sa_data, nla_data(tb[IFLA_ADDRESS]), dev->addr_len); - err = netif_set_mac_address_user(dev, sa, extack); + if (!netdev_need_ops_lock(dev)) + netdev_lock(dev); + err = netif_set_mac_address(dev, sa, extack); + if (!netdev_need_ops_lock(dev)) + netdev_unlock(dev); kfree(sa); if (err) goto errout;