From: Johan Hovold <johan+linaro@kernel.org>
To: Marc Zyngier <maz@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Rob Herring <robh@kernel.org>,
linux-kernel@vger.kernel.org,
Johan Hovold <johan+linaro@kernel.org>,
Dmitry Torokhov <dtor@chromium.org>,
Jon Hunter <jonathanh@nvidia.com>
Subject: [PATCH] irqdomain: Fix mapping-creation race
Date: Thu, 28 Jul 2022 11:27:10 +0200 [thread overview]
Message-ID: <20220728092710.21190-1-johan+linaro@kernel.org> (raw)
Parallel probing (e.g. due to asynchronous probing) of devices that share
interrupts can currently result in two mappings for the same hardware
interrupt to be created.
Add a serialising mapping mutex so that looking for an existing mapping
before creating a new one is done atomically.
Note that serialising the lookup and creation in
irq_create_mapping_affinity() would have been enough to prevent the
duplicate mapping, but that could instead cause
irq_create_fwspec_mapping() to fail when there is a race.
Fixes: 765230b5f084 ("driver-core: add asynchronous probing support for drivers")
Fixes: b62b2cf5759b ("irqdomain: Fix handling of type settings for existing mappings")
Cc: Dmitry Torokhov <dtor@chromium.org>
Cc: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
kernel/irq/irqdomain.c | 46 +++++++++++++++++++++++++++++++-----------
1 file changed, 34 insertions(+), 12 deletions(-)
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index 8fe1da9614ee..d263a7dd4170 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -22,6 +22,7 @@
static LIST_HEAD(irq_domain_list);
static DEFINE_MUTEX(irq_domain_mutex);
+static DEFINE_MUTEX(irq_mapping_mutex);
static struct irq_domain *irq_default_domain;
@@ -669,7 +670,7 @@ EXPORT_SYMBOL_GPL(irq_create_direct_mapping);
#endif
/**
- * irq_create_mapping_affinity() - Map a hardware interrupt into linux irq space
+ * __irq_create_mapping_affinity() - Map a hardware interrupt into linux irq space
* @domain: domain owning this hardware interrupt or NULL for default domain
* @hwirq: hardware irq number in that domain space
* @affinity: irq affinity
@@ -679,9 +680,9 @@ EXPORT_SYMBOL_GPL(irq_create_direct_mapping);
* If the sense/trigger is to be specified, set_irq_type() should be called
* on the number returned from that call.
*/
-unsigned int irq_create_mapping_affinity(struct irq_domain *domain,
- irq_hw_number_t hwirq,
- const struct irq_affinity_desc *affinity)
+static unsigned int __irq_create_mapping_affinity(struct irq_domain *domain,
+ irq_hw_number_t hwirq,
+ const struct irq_affinity_desc *affinity)
{
struct device_node *of_node;
int virq;
@@ -724,6 +725,19 @@ unsigned int irq_create_mapping_affinity(struct irq_domain *domain,
return virq;
}
+
+unsigned int irq_create_mapping_affinity(struct irq_domain *domain,
+ irq_hw_number_t hwirq,
+ const struct irq_affinity_desc *affinity)
+{
+ unsigned int virq;
+
+ mutex_lock(&irq_mapping_mutex);
+ virq = __irq_create_mapping_affinity(domain, hwirq, affinity);
+ mutex_unlock(&irq_mapping_mutex);
+
+ return virq;
+}
EXPORT_SYMBOL_GPL(irq_create_mapping_affinity);
static int irq_domain_translate(struct irq_domain *d,
@@ -789,6 +803,8 @@ unsigned int irq_create_fwspec_mapping(struct irq_fwspec *fwspec)
if (WARN_ON(type & ~IRQ_TYPE_SENSE_MASK))
type &= IRQ_TYPE_SENSE_MASK;
+ mutex_lock(&irq_mapping_mutex);
+
/*
* If we've already configured this interrupt,
* don't do it again, or hell will break loose.
@@ -801,7 +817,7 @@ unsigned int irq_create_fwspec_mapping(struct irq_fwspec *fwspec)
* interrupt number.
*/
if (type == IRQ_TYPE_NONE || type == irq_get_trigger_type(virq))
- return virq;
+ goto out;
/*
* If the trigger type has not been set yet, then set
@@ -810,26 +826,26 @@ unsigned int irq_create_fwspec_mapping(struct irq_fwspec *fwspec)
if (irq_get_trigger_type(virq) == IRQ_TYPE_NONE) {
irq_data = irq_get_irq_data(virq);
if (!irq_data)
- return 0;
+ goto err;
irqd_set_trigger_type(irq_data, type);
- return virq;
+ goto out;
}
pr_warn("type mismatch, failed to map hwirq-%lu for %s!\n",
hwirq, of_node_full_name(to_of_node(fwspec->fwnode)));
- return 0;
+ goto err;
}
if (irq_domain_is_hierarchy(domain)) {
virq = irq_domain_alloc_irqs(domain, 1, NUMA_NO_NODE, fwspec);
if (virq <= 0)
- return 0;
+ goto err;
} else {
/* Create mapping */
- virq = irq_create_mapping(domain, hwirq);
+ virq = __irq_create_mapping_affinity(domain, hwirq, NULL);
if (!virq)
- return virq;
+ goto err;
}
irq_data = irq_get_irq_data(virq);
@@ -838,13 +854,19 @@ unsigned int irq_create_fwspec_mapping(struct irq_fwspec *fwspec)
irq_domain_free_irqs(virq, 1);
else
irq_dispose_mapping(virq);
- return 0;
+ goto err;
}
/* Store trigger type */
irqd_set_trigger_type(irq_data, type);
+out:
+ mutex_unlock(&irq_mapping_mutex);
return virq;
+err:
+ mutex_unlock(&irq_mapping_mutex);
+
+ return 0;
}
EXPORT_SYMBOL_GPL(irq_create_fwspec_mapping);
--
2.35.1
next reply other threads:[~2022-07-28 9:28 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-28 9:27 Johan Hovold [this message]
2022-07-28 9:33 ` [PATCH] irqdomain: Fix mapping-creation race Johan Hovold
2022-07-28 11:48 ` Marc Zyngier
2022-07-28 12:56 ` Johan Hovold
2022-07-28 13:14 ` Marc Zyngier
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