From f0f393877c71ad227d36705d61d1e4062bc29cf5 Mon Sep 17 00:00:00 2001 From: Ross Lagerwall Date: Tue, 10 May 2016 16:11:00 +0100 Subject: [PATCH] xen/events: Don't move disabled irqs Commit ff1e22e7a638 ("xen/events: Mask a moving irq") open-coded irq_move_irq() but left out checking if the IRQ is disabled. This broke resuming from suspend since it tries to move a (disabled) irq without holding the IRQ's desc->lock. Fix it by adding in a check for disabled IRQs. The resulting stacktrace was: kernel BUG at /build/linux-UbQGH5/linux-4.4.0/kernel/irq/migration.c:31! invalid opcode: 0000 [#1] SMP Modules linked in: xenfs xen_privcmd ... CPU: 0 PID: 9 Comm: migration/0 Not tainted 4.4.0-22-generic #39-Ubuntu Hardware name: Xen HVM domU, BIOS 4.6.1-xs125180 05/04/2016 task: ffff88003d75ee00 ti: ffff88003d7bc000 task.ti: ffff88003d7bc000 RIP: 0010:[] [] irq_move_masked_irq+0xd2/0xe0 RSP: 0018:ffff88003d7bfc50 EFLAGS: 00010046 RAX: 0000000000000000 RBX: ffff88003d40ba00 RCX: 0000000000000001 RDX: 0000000000000001 RSI: 0000000000000100 RDI: ffff88003d40bad8 RBP: ffff88003d7bfc68 R08: 0000000000000000 R09: ffff88003d000000 R10: 0000000000000000 R11: 000000000000023c R12: ffff88003d40bad0 R13: ffffffff81f3a4a0 R14: 0000000000000010 R15: 00000000ffffffff FS: 0000000000000000(0000) GS:ffff88003da00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd4264de624 CR3: 0000000037922000 CR4: 00000000003406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: ffff88003d40ba38 0000000000000024 0000000000000000 ffff88003d7bfca0 ffffffff814c8d92 00000010813ef89d 00000000805ea732 0000000000000009 0000000000000024 ffff88003cc39b80 ffff88003d7bfce0 ffffffff814c8f66 Call Trace: [] eoi_pirq+0xb2/0xf0 [] __startup_pirq+0xe6/0x150 [] xen_irq_resume+0x319/0x360 [] xen_suspend+0xb5/0x180 [] multi_cpu_stop+0xb5/0xe0 [] ? cpu_stop_queue_work+0x80/0x80 [] cpu_stopper_thread+0xb0/0x140 [] ? finish_task_switch+0x76/0x220 [] ? __raw_callee_save___pv_queued_spin_unlock+0x11/0x20 [] smpboot_thread_fn+0x105/0x160 [] ? sort_range+0x30/0x30 [] kthread+0xd8/0xf0 [] ? kthread_create_on_node+0x1e0/0x1e0 [] ret_from_fork+0x3f/0x70 [] ? kthread_create_on_node+0x1e0/0x1e0 Signed-off-by: Ross Lagerwall Reviewed-by: Boris Ostrovsky Cc: Signed-off-by: David Vrabel --- drivers/xen/events/events_base.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c index cb7138c97c69..71d49a95f8c0 100644 --- a/drivers/xen/events/events_base.c +++ b/drivers/xen/events/events_base.c @@ -487,7 +487,8 @@ static void eoi_pirq(struct irq_data *data) if (!VALID_EVTCHN(evtchn)) return; - if (unlikely(irqd_is_setaffinity_pending(data))) { + if (unlikely(irqd_is_setaffinity_pending(data)) && + likely(!irqd_irq_disabled(data))) { int masked = test_and_set_mask(evtchn); clear_evtchn(evtchn); @@ -1370,7 +1371,8 @@ static void ack_dynirq(struct irq_data *data) if (!VALID_EVTCHN(evtchn)) return; - if (unlikely(irqd_is_setaffinity_pending(data))) { + if (unlikely(irqd_is_setaffinity_pending(data)) && + likely(!irqd_irq_disabled(data))) { int masked = test_and_set_mask(evtchn); clear_evtchn(evtchn); -- 2.30.2