From 1bb86cf8f44b1c1a320566558250b1f5121f6fd3 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Tue, 14 Jan 2025 19:53:16 -0800 Subject: net: protect threaded status of NAPI with netdev_lock() Now that NAPI instances can't come and go without holding netdev->lock we can trivially switch from rtnl_lock() to netdev_lock() for setting netdev->threaded via sysfs. Note that since we do not lock netdev_lock around sysfs calls in the core we don't have to "trylock" like we do with rtnl_lock. Reviewed-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250115035319.559603-9-kuba@kernel.org Signed-off-by: Jakub Kicinski --- include/linux/netdevice.h | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 3941e4d0073e..20e773bbd181 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -384,7 +384,7 @@ struct napi_struct { int rx_count; /* length of rx_list */ unsigned int napi_id; /* protected by netdev_lock */ struct hrtimer timer; - struct task_struct *thread; + struct task_struct *thread; /* protected by netdev_lock */ unsigned long gro_flush_timeout; unsigned long irq_suspend_timeout; u32 defer_hard_irqs; @@ -2451,11 +2451,13 @@ struct net_device { * Drivers are free to use it for other protection. * * Protects: - * @napi_list, @net_shaper_hierarchy, @reg_state + * @napi_list, @net_shaper_hierarchy, @reg_state, @threaded * * Partially protects (writers must hold both @lock and rtnl_lock): * @up * + * Also protects some fields in struct napi_struct. + * * Ordering: take after rtnl_lock. */ struct mutex lock; @@ -2697,6 +2699,13 @@ static inline void netdev_assert_locked(struct net_device *dev) lockdep_assert_held(&dev->lock); } +static inline void netdev_assert_locked_or_invisible(struct net_device *dev) +{ + if (dev->reg_state == NETREG_REGISTERED || + dev->reg_state == NETREG_UNREGISTERING) + netdev_assert_locked(dev); +} + static inline void netif_napi_set_irq(struct napi_struct *napi, int irq) { napi->irq = irq; -- cgit v1.2.3