From 317e49358ebbf6390fa439ef3c142f9239dd25fb Mon Sep 17 00:00:00 2001 From: Kevin Hao Date: Wed, 18 Mar 2026 14:36:58 +0800 Subject: [PATCH 1/2] net: macb: Move devm_{free,request}_irq() out of spin lock area MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The devm_free_irq() and devm_request_irq() functions should not be executed in an atomic context. During device suspend, all userspace processes and most kernel threads are frozen. Additionally, we flush all tx/rx status, disable all macb interrupts, and halt rx operations. Therefore, it is safe to split the region protected by bp->lock into two independent sections, allowing devm_free_irq() and devm_request_irq() to run in a non-atomic context. This modification resolves the following lockdep warning: BUG: sleeping function called from invalid context at kernel/locking/mutex.c:591 in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 501, name: rtcwake preempt_count: 1, expected: 0 RCU nest depth: 1, expected: 0 7 locks held by rtcwake/501: #0: ffff0008038c3408 (sb_writers#5){.+.+}-{0:0}, at: vfs_write+0xf8/0x368 #1: ffff0008049a5e88 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_fop_write_iter+0xbc/0x1c8 #2: ffff00080098d588 (kn->active#70){.+.+}-{0:0}, at: kernfs_fop_write_iter+0xcc/0x1c8 #3: ffff800081c84888 (system_transition_mutex){+.+.}-{4:4}, at: pm_suspend+0x1ec/0x290 #4: ffff0008009ba0f8 (&dev->mutex){....}-{4:4}, at: device_suspend+0x118/0x4f0 #5: ffff800081d00458 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire+0x4/0x48 #6: ffff0008031fb9e0 (&bp->lock){-.-.}-{3:3}, at: macb_suspend+0x144/0x558 irq event stamp: 8682 hardirqs last enabled at (8681): [] _raw_spin_unlock_irqrestore+0x44/0x88 hardirqs last disabled at (8682): [] _raw_spin_lock_irqsave+0x38/0x98 softirqs last enabled at (7322): [] handle_softirqs+0x52c/0x588 softirqs last disabled at (7317): [] __do_softirq+0x20/0x2c CPU: 1 UID: 0 PID: 501 Comm: rtcwake Not tainted 7.0.0-rc3-next-20260310-yocto-standard+ #125 PREEMPT Hardware name: ZynqMP ZCU102 Rev1.1 (DT) Call trace: show_stack+0x24/0x38 (C) __dump_stack+0x28/0x38 dump_stack_lvl+0x64/0x88 dump_stack+0x18/0x24 __might_resched+0x200/0x218 __might_sleep+0x38/0x98 __mutex_lock_common+0x7c/0x1378 mutex_lock_nested+0x38/0x50 free_irq+0x68/0x2b0 devm_irq_release+0x24/0x38 devres_release+0x40/0x80 devm_free_irq+0x48/0x88 macb_suspend+0x298/0x558 device_suspend+0x218/0x4f0 dpm_suspend+0x244/0x3a0 dpm_suspend_start+0x50/0x78 suspend_devices_and_enter+0xec/0x560 pm_suspend+0x194/0x290 state_store+0x110/0x158 kobj_attr_store+0x1c/0x30 sysfs_kf_write+0xa8/0xd0 kernfs_fop_write_iter+0x11c/0x1c8 vfs_write+0x248/0x368 ksys_write+0x7c/0xf8 __arm64_sys_write+0x28/0x40 invoke_syscall+0x4c/0xe8 el0_svc_common+0x98/0xf0 do_el0_svc+0x28/0x40 el0_svc+0x54/0x1e0 el0t_64_sync_handler+0x84/0x130 el0t_64_sync+0x198/0x1a0 Fixes: 558e35ccfe95 ("net: macb: WoL support for GEM type of Ethernet controller") Cc: stable@vger.kernel.org Reviewed-by: Théo Lebrun Signed-off-by: Kevin Hao Link: https://patch.msgid.link/20260318-macb-irq-v2-1-f1179768ab24@gmail.com Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/cadence/macb_main.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c index c16ac9c76aa3..1b95226ae696 100644 --- a/drivers/net/ethernet/cadence/macb_main.c +++ b/drivers/net/ethernet/cadence/macb_main.c @@ -5835,6 +5835,7 @@ static int __maybe_unused macb_suspend(struct device *dev) /* write IP address into register */ tmp |= MACB_BFEXT(IP, be32_to_cpu(ifa->ifa_local)); } + spin_unlock_irqrestore(&bp->lock, flags); /* Change interrupt handler and * Enable WoL IRQ on queue 0 @@ -5847,11 +5848,12 @@ static int __maybe_unused macb_suspend(struct device *dev) dev_err(dev, "Unable to request IRQ %d (error %d)\n", bp->queues[0].irq, err); - spin_unlock_irqrestore(&bp->lock, flags); return err; } + spin_lock_irqsave(&bp->lock, flags); queue_writel(bp->queues, IER, GEM_BIT(WOL)); gem_writel(bp, WOL, tmp); + spin_unlock_irqrestore(&bp->lock, flags); } else { err = devm_request_irq(dev, bp->queues[0].irq, macb_wol_interrupt, IRQF_SHARED, netdev->name, bp->queues); @@ -5859,13 +5861,13 @@ static int __maybe_unused macb_suspend(struct device *dev) dev_err(dev, "Unable to request IRQ %d (error %d)\n", bp->queues[0].irq, err); - spin_unlock_irqrestore(&bp->lock, flags); return err; } + spin_lock_irqsave(&bp->lock, flags); queue_writel(bp->queues, IER, MACB_BIT(WOL)); macb_writel(bp, WOL, tmp); + spin_unlock_irqrestore(&bp->lock, flags); } - spin_unlock_irqrestore(&bp->lock, flags); enable_irq_wake(bp->queues[0].irq); } @@ -5932,6 +5934,8 @@ static int __maybe_unused macb_resume(struct device *dev) queue_readl(bp->queues, ISR); if (bp->caps & MACB_CAPS_ISR_CLEAR_ON_WRITE) queue_writel(bp->queues, ISR, -1); + spin_unlock_irqrestore(&bp->lock, flags); + /* Replace interrupt handler on queue 0 */ devm_free_irq(dev, bp->queues[0].irq, bp->queues); err = devm_request_irq(dev, bp->queues[0].irq, macb_interrupt, @@ -5940,10 +5944,8 @@ static int __maybe_unused macb_resume(struct device *dev) dev_err(dev, "Unable to request IRQ %d (error %d)\n", bp->queues[0].irq, err); - spin_unlock_irqrestore(&bp->lock, flags); return err; } - spin_unlock_irqrestore(&bp->lock, flags); disable_irq_wake(bp->queues[0].irq); From baa35a698cea26930679a20a7550bbb4c8319725 Mon Sep 17 00:00:00 2001 From: Kevin Hao Date: Wed, 18 Mar 2026 14:36:59 +0800 Subject: [PATCH 2/2] net: macb: Protect access to net_device::ip_ptr with RCU lock MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Access to net_device::ip_ptr and its associated members must be protected by an RCU lock. Since we are modifying this piece of code, let's also move it to execute only when WAKE_ARP is enabled. To minimize the duration of the RCU lock, a local variable is used to temporarily store the IP address. This change resolves the following RCU check warning: WARNING: suspicious RCU usage 7.0.0-rc3-next-20260310-yocto-standard+ #122 Not tainted ----------------------------- drivers/net/ethernet/cadence/macb_main.c:5944 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 5 locks held by rtcwake/518: #0: ffff000803ab1408 (sb_writers#5){.+.+}-{0:0}, at: vfs_write+0xf8/0x368 #1: ffff0008090bf088 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_fop_write_iter+0xbc/0x1c8 #2: ffff00080098d588 (kn->active#70){.+.+}-{0:0}, at: kernfs_fop_write_iter+0xcc/0x1c8 #3: ffff800081c84888 (system_transition_mutex){+.+.}-{4:4}, at: pm_suspend+0x1ec/0x290 #4: ffff0008009ba0f8 (&dev->mutex){....}-{4:4}, at: device_suspend+0x118/0x4f0 stack backtrace: CPU: 3 UID: 0 PID: 518 Comm: rtcwake Not tainted 7.0.0-rc3-next-20260310-yocto-standard+ #122 PREEMPT Hardware name: ZynqMP ZCU102 Rev1.1 (DT) Call trace: show_stack+0x24/0x38 (C) __dump_stack+0x28/0x38 dump_stack_lvl+0x64/0x88 dump_stack+0x18/0x24 lockdep_rcu_suspicious+0x134/0x1d8 macb_suspend+0xd8/0x4c0 device_suspend+0x218/0x4f0 dpm_suspend+0x244/0x3a0 dpm_suspend_start+0x50/0x78 suspend_devices_and_enter+0xec/0x560 pm_suspend+0x194/0x290 state_store+0x110/0x158 kobj_attr_store+0x1c/0x30 sysfs_kf_write+0xa8/0xd0 kernfs_fop_write_iter+0x11c/0x1c8 vfs_write+0x248/0x368 ksys_write+0x7c/0xf8 __arm64_sys_write+0x28/0x40 invoke_syscall+0x4c/0xe8 el0_svc_common+0x98/0xf0 do_el0_svc+0x28/0x40 el0_svc+0x54/0x1e0 el0t_64_sync_handler+0x84/0x130 el0t_64_sync+0x198/0x1a0 Fixes: 0cb8de39a776 ("net: macb: Add ARP support to WOL") Signed-off-by: Kevin Hao Cc: stable@vger.kernel.org Reviewed-by: Théo Lebrun Link: https://patch.msgid.link/20260318-macb-irq-v2-2-f1179768ab24@gmail.com Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/cadence/macb_main.c | 25 +++++++++++++++--------- 1 file changed, 16 insertions(+), 9 deletions(-) diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c index 1b95226ae696..944aab71795c 100644 --- a/drivers/net/ethernet/cadence/macb_main.c +++ b/drivers/net/ethernet/cadence/macb_main.c @@ -5776,9 +5776,9 @@ static int __maybe_unused macb_suspend(struct device *dev) struct macb_queue *queue; struct in_device *idev; unsigned long flags; + u32 tmp, ifa_local; unsigned int q; int err; - u32 tmp; if (!device_may_wakeup(&bp->dev->dev)) phy_exit(bp->phy); @@ -5787,14 +5787,21 @@ static int __maybe_unused macb_suspend(struct device *dev) return 0; if (bp->wol & MACB_WOL_ENABLED) { - /* Check for IP address in WOL ARP mode */ - idev = __in_dev_get_rcu(bp->dev); - if (idev) - ifa = rcu_dereference(idev->ifa_list); - if ((bp->wolopts & WAKE_ARP) && !ifa) { - netdev_err(netdev, "IP address not assigned as required by WoL walk ARP\n"); - return -EOPNOTSUPP; + if (bp->wolopts & WAKE_ARP) { + /* Check for IP address in WOL ARP mode */ + rcu_read_lock(); + idev = __in_dev_get_rcu(bp->dev); + if (idev) + ifa = rcu_dereference(idev->ifa_list); + if (!ifa) { + rcu_read_unlock(); + netdev_err(netdev, "IP address not assigned as required by WoL walk ARP\n"); + return -EOPNOTSUPP; + } + ifa_local = be32_to_cpu(ifa->ifa_local); + rcu_read_unlock(); } + spin_lock_irqsave(&bp->lock, flags); /* Disable Tx and Rx engines before disabling the queues, @@ -5833,7 +5840,7 @@ static int __maybe_unused macb_suspend(struct device *dev) if (bp->wolopts & WAKE_ARP) { tmp |= MACB_BIT(ARP); /* write IP address into register */ - tmp |= MACB_BFEXT(IP, be32_to_cpu(ifa->ifa_local)); + tmp |= MACB_BFEXT(IP, ifa_local); } spin_unlock_irqrestore(&bp->lock, flags);