From 4c9c81a0860415284e9d260f998fbd755d3a7469 Mon Sep 17 00:00:00 2001 From: Vladimir Murzin Date: Fri, 31 Jul 2026 13:26:46 +0100 Subject: [PATCH] arm64: smp: Fix IPI teardown for GICv5 flow Sashiko reported that during CPU offlining, __cpu_disable() is executed by the stopper thread via take_cpu_down() with local interrupts disabled. __cpu_disable() calls ipi_teardown(), which invokes ipi_lpi_disable(). For the GICv5 flow, this eventually calls the sleepable disable_irq(). This can be reproduced easily with CONFIG_DEBUG_ATOMIC_SLEEP=y by offlining a CPU: BUG: sleeping function called from invalid context at kernel/irq/manage.c:702 in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 20, name: migration/1 preempt_count: 1, expected: 0 no locks held by migration/1/20. irq event stamp: 186 hardirqs last enabled at (185): [] _raw_spin_unlock_irq+0x38/0x68 hardirqs last disabled at (186): [] multi_cpu_stop+0xc8/0x190 softirqs last enabled at (80): [] handle_softirqs+0x410/0x468 softirqs last disabled at (75): [] __do_softirq+0x1c/0x28 Fix this by using disable_irq_nosync() instead, which is safe in this atomic context. Fixes: ba1004f861d1 ("arm64: smp: Support non-SGIs for IPIs") Signed-off-by: Vladimir Murzin Signed-off-by: Will Deacon --- arch/arm64/kernel/smp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index cdcdd160e5b6..3ab90aa24efb 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -1086,7 +1086,7 @@ static void ipi_teardown(int cpu) disable_percpu_irq(ipi_irq_base + i); } } else { - disable_irq(irq_desc_get_irq(get_ipi_desc(cpu, i))); + disable_irq_nosync(irq_desc_get_irq(get_ipi_desc(cpu, i))); } } }