The following call-chain leads to misuse of spinlock_irq
when spinlock_irqsave was hold.
irq_set_vcpu_affinity
-> irq_get_desc_lock (spinlock_irqsave)
-> its_irq_set_vcpu_affinity
-> guard(raw_spin_lock_irq) <--- this enables interrupts
-> irq_put_desc_unlock // <--- WARN IRQs enabled
Fix the issue by using guard(raw_spinlock), since the function is
already called with irqsave and raw_spin_lock was used before the commit
b97e8a2f7130 ("irqchip/gic-v3-its: Fix potential race condition in its_vlpi_prop_update()")
introducing the guard as well.
This was discovered through the lock debugging, and the corresponding
log is as follows:
raw_local_irq_restore() called with IRQs enabled
WARNING: CPU: 38 PID: 444 at kernel/locking/irqflag-debug.c:10 warn_bogus_irq_restore+0x2c/0x38
Call trace:
warn_bogus_irq_restore+0x2c/0x38
_raw_spin_unlock_irqrestore+0x68/0x88
__irq_put_desc_unlock+0x1c/0x48
irq_set_vcpu_affinity+0x74/0xc0
its_map_vlpi+0x44/0x88
kvm_vgic_v4_set_forwarding+0x148/0x230
kvm_arch_irq_bypass_add_producer+0x20/0x28
__connect+0x98/0xb8
irq_bypass_register_consumer+0x150/0x178
kvm_irqfd+0x6dc/0x744
kvm_vm_ioctl+0xe44/0x16b0
Fixes: b97e8a2f7130 ("irqchip/gic-v3-its: Fix potential race condition in its_vlpi_prop_update()")
Signed-off-by: Tomas Krcka <krckatom@xxxxxxxxx>
Reviewed-by: Marc Zyngier <maz@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
---
drivers/irqchip/irq-gic-v3-its.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 92244cfa0464..8c3ec5734f1e 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -2045,7 +2045,7 @@ static int its_irq_set_vcpu_affinity(struct irq_data *d, void *vcpu_info)
if (!is_v4(its_dev->its))
return -EINVAL;
- guard(raw_spinlock_irq)(&its_dev->event_map.vlpi_lock);
+ guard(raw_spinlock)(&its_dev->event_map.vlpi_lock);
/* Unmap request? */
if (!info)
--
2.40.1
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