[PATCH 3.12 41/56] xen/events: Don't move disabled irqs
From: Jiri Slaby
Date: Wed Jun 15 2016 - 03:31:47 EST
From: Ross Lagerwall <ross.lagerwall@xxxxxxxxxx>
3.12-stable review patch. If anyone has any objections, please let me know.
===============
commit f0f393877c71ad227d36705d61d1e4062bc29cf5 upstream.
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:[<ffffffff810e26e2>] [<ffffffff810e26e2>] 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:
[<ffffffff814c8d92>] eoi_pirq+0xb2/0xf0
[<ffffffff814c8f66>] __startup_pirq+0xe6/0x150
[<ffffffff814ca659>] xen_irq_resume+0x319/0x360
[<ffffffff814c7e75>] xen_suspend+0xb5/0x180
[<ffffffff81120155>] multi_cpu_stop+0xb5/0xe0
[<ffffffff811200a0>] ? cpu_stop_queue_work+0x80/0x80
[<ffffffff811203d0>] cpu_stopper_thread+0xb0/0x140
[<ffffffff810a94e6>] ? finish_task_switch+0x76/0x220
[<ffffffff810ca731>] ? __raw_callee_save___pv_queued_spin_unlock+0x11/0x20
[<ffffffff810a3935>] smpboot_thread_fn+0x105/0x160
[<ffffffff810a3830>] ? sort_range+0x30/0x30
[<ffffffff810a0588>] kthread+0xd8/0xf0
[<ffffffff810a04b0>] ? kthread_create_on_node+0x1e0/0x1e0
[<ffffffff8182568f>] ret_from_fork+0x3f/0x70
[<ffffffff810a04b0>] ? kthread_create_on_node+0x1e0/0x1e0
Signed-off-by: Ross Lagerwall <ross.lagerwall@xxxxxxxxxx>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
Signed-off-by: David Vrabel <david.vrabel@xxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
drivers/xen/events.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 3715a54117bb..19bd74cf0aba 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -576,7 +576,8 @@ 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);
@@ -1616,7 +1617,8 @@ 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);
--
2.9.0