Messages in this thread Patch in this message | | | From | Johan Hovold <> | Subject | [PATCH] irqdomain: Fix mapping-creation race | Date | Thu, 28 Jul 2022 11:27:10 +0200 |
| |
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
| |