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From:   Kassey Li <quic_yingangl@quicinc.com>
To:     tj@kernel.org, akpm@linux-foundation.org
Cc:     Kassey Li <quic_yingangl@quicinc.com>, jiangshanlai@gmail.com,
        linux-kernel@vger.kernel.org
Subject: [PATCH] workqueue: avoid re-entry of pwq->pool->lock through __queue_work
Date:   Wed, 27 Jul 2022 19:04:26 +0800
Message-Id: <20220727110426.19079-1-quic_yingangl@quicinc.com>
Precedence: bulk

[0:swapper/4]BUG: spinlock recursion on CPU#4, swapper/4/0
[0:swapper/4]lock: 0xffffff8000c0f400, .magic: dead4ead, .owner:
swapper/4/0, .owner_cpu: 4
[0:swapper/4]CPU: 4 PID: 0 Comm: swapper/4 Tainted: G S
[0:swapper/4]Call trace:
[0:swapper/4] dump_backtrace.cfi_jt+0x0/0x8
[0:swapper/4] show_stack+0x1c/0x2c
[0:swapper/4] dump_stack_lvl+0xd8/0x16c
[0:swapper/4] spin_dump+0x104/0x278
[0:swapper/4] do_raw_spin_lock+0xec/0x15c
[0:swapper/4] _raw_spin_lock+0x28/0x3c
[0:swapper/4] __queue_work+0x1fc/0x618
[0:swapper/4] queue_work_on+0x64/0x134
[0:swapper/4] memlat_hrtimer_handler+0x28/0x3c [memlat]
[0:swapper/4] __run_hrtimer+0xe8/0x448
[0:swapper/4] hrtimer_interrupt+0x184/0x40c
[0:swapper/4] arch_timer_handler_virt+0x5c/0x98
[0:swapper/4] handle_percpu_devid_irq+0xd8/0x3e0
[0:swapper/4] __handle_domain_irq+0xd0/0x19c
[0:swapper/4] gic_handle_irq+0x6c/0x134
[0:swapper/4] el1_irq+0xe4/0x1c0
[0:swapper/4] _raw_spin_unlock_irqrestore+0x2c/0x60
[0:swapper/4] try_to_wake_up.llvm.14610847381734009831+0x334/0x888
[0:swapper/4] wake_up_process+0x1c/0x2c
[0:swapper/4] __queue_work+0x3e8/0x618
[0:swapper/4] delayed_work_timer_fn+0x24/0x34
[0:swapper/4] call_timer_fn+0x58/0x268
[0:swapper/4] expire_timers+0xe0/0x1c4
[0:swapper/4] __run_timers+0x16c/0x1c4
[0:swapper/4] run_timer_softirq+0x34/0x60
[0:swapper/4] efi_header_end+0x198/0x59c
[0:swapper/4] __irq_exit_rcu+0xdc/0xf0
[0:swapper/4] irq_exit+0x14/0x50
[0:swapper/4] __handle_domain_irq+0xd4/0x19c
[0:swapper/4] gic_handle_irq+0x6c/0x134
[0:swapper/4] el1_irq+0xe4/0x1c0
[0:swapper/4] cpuidle_enter_state+0x1b4/0x5dc
[0:swapper/4] cpuidle_enter+0x3c/0x58
[0:swapper/4] do_idle.llvm.6296834828977863291+0x1f4/0x2e8
[0:swapper/4] cpu_startup_entry+0x28/0x2c
[0:swapper/4] secondary_start_kernel+0x1c8/0x230

Signed-off-by: Kassey Li <quic_yingangl@quicinc.com>
---
 kernel/workqueue.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 1ea50f6be843..f23491f373b1 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -1468,10 +1468,10 @@ static void __queue_work(int cpu, struct workqueue_struct *wq,
 		} else {
 			/* meh... not running there, queue here */
 			raw_spin_unlock(&last_pool->lock);
-			raw_spin_lock(&pwq->pool->lock);
+			raw_spin_lock_irq(&pwq->pool->lock);
 		}
 	} else {
-		raw_spin_lock(&pwq->pool->lock);
+		raw_spin_lock_irq(&pwq->pool->lock);
 	}
 
 	/*
@@ -1484,7 +1484,7 @@ static void __queue_work(int cpu, struct workqueue_struct *wq,
 	 */
 	if (unlikely(!pwq->refcnt)) {
 		if (wq->flags & WQ_UNBOUND) {
-			raw_spin_unlock(&pwq->pool->lock);
+			raw_spin_unlock_irq(&pwq->pool->lock);
 			cpu_relax();
 			goto retry;
 		}
@@ -1517,7 +1517,7 @@ static void __queue_work(int cpu, struct workqueue_struct *wq,
 	insert_work(pwq, work, worklist, work_flags);
 
 out:
-	raw_spin_unlock(&pwq->pool->lock);
+	raw_spin_unlock_irq(&pwq->pool->lock);
 	rcu_read_unlock();
 }
 
-- 
2.17.1