[PATCH v3 2/5] irqchip/mips-gic: Fix recursive acquisition of gic_lock in gic_set_affinity()
From: Benoît Monin <benoit.monin@bootlin.com>
Date: 2026-09-07 12:47:20
Also in:
lkml
Subsystem:
irqchip drivers, mips core drivers, the rest · Maintainers:
Thomas Gleixner, Thomas Bogendoerfer, Linus Torvalds
Commit 322a90638768 ("irqchip/mips-gic: Multi-cluster support")
made gic_set_affinity() call gic_set_type() when an interrupt's
affinity is moved between clusters. gic_set_type() takes gic_lock with
raw_spin_lock_irqsave(), but gic_set_affinity() holds gic_lock at that
point, so the same raw spinlock is acquired twice, triggering a deadlock.
Split gic_set_type() into a gic_set_type_locked() helper that assumes
gic_lock is already held. gic_set_type() takes gic_lock and calls the
helper, and gic_set_affinity() calls gic_set_type_locked() directly,
since it already holds gic_lock.
Fixes: 322a90638768 ("irqchip/mips-gic: Multi-cluster support")
Signed-off-by: Benoît Monin <benoit.monin@bootlin.com>
---
drivers/irqchip/irq-mips-gic.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)
diff --git a/drivers/irqchip/irq-mips-gic.c b/drivers/irqchip/irq-mips-gic.c
index 3b31cbcbed6f..f2ae60d39d66 100644
--- a/drivers/irqchip/irq-mips-gic.c
+++ b/drivers/irqchip/irq-mips-gic.c@@ -297,14 +297,14 @@ static void gic_ack_irq(struct irq_data *d) } } -static int gic_set_type(struct irq_data *d, unsigned int type) +static int gic_set_type_locked(struct irq_data *d, unsigned int type) { unsigned int irq, pol, trig, dual; - unsigned long flags; + + lockdep_assert_held(&gic_lock); irq = GIC_HWIRQ_TO_SHARED(d->hwirq); - raw_spin_lock_irqsave(&gic_lock, flags); switch (type & IRQ_TYPE_SENSE_MASK) { case IRQ_TYPE_EDGE_FALLING: pol = GIC_POL_FALLING_EDGE;
@@ -351,11 +351,16 @@ static int gic_set_type(struct irq_data *d, unsigned int type) else irq_set_chip_handler_name_locked(d, &gic_level_irq_controller, handle_level_irq, NULL); - raw_spin_unlock_irqrestore(&gic_lock, flags); return 0; } +static int gic_set_type(struct irq_data *d, unsigned int type) +{ + guard(raw_spinlock_irqsave)(&gic_lock); + return gic_set_type_locked(d, type); +} + #ifdef CONFIG_SMP static int gic_set_affinity(struct irq_data *d, const struct cpumask *cpumask, bool force)
@@ -407,7 +412,7 @@ static int gic_set_affinity(struct irq_data *d, const struct cpumask *cpumask, * trigger type in the new cluster. */ if (cl != old_cl) - gic_set_type(d, irqd_get_trigger_type(d)); + gic_set_type_locked(d, irqd_get_trigger_type(d)); /* Route the interrupt to its new VP(E) */ if (gic_irq_lock_cluster(d)) {
--
2.55.0