Commit 601363cc authored by Johan Hovold's avatar Johan Hovold Committed by Marc Zyngier

irqdomain: Fix mapping-creation race

Parallel probing of devices that share interrupts (e.g. when a driver
uses asynchronous probing) can currently result in two mappings for the
same hardware interrupt to be created due to missing serialisation.

Make sure to hold the irq_domain_mutex when creating mappings so that
looking for an existing mapping before creating a new one is done
atomically.

Fixes: 765230b5 ("driver-core: add asynchronous probing support for drivers")
Fixes: b62b2cf5 ("irqdomain: Fix handling of type settings for existing mappings")
Link: https://lore.kernel.org/r/YuJXMHoT4ijUxnRb@hovoldconsulting.com
Cc: stable@vger.kernel.org      # 4.8
Cc: Dmitry Torokhov <dtor@chromium.org>
Cc: Jon Hunter <jonathanh@nvidia.com>
Tested-by: default avatarHsin-Yi Wang <hsinyi@chromium.org>
Tested-by: default avatarMark-PK Tsai <mark-pk.tsai@mediatek.com>
Signed-off-by: default avatarJohan Hovold <johan+linaro@kernel.org>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230213104302.17307-7-johan+linaro@kernel.org
parent d55f7f4c
......@@ -25,6 +25,9 @@ static DEFINE_MUTEX(irq_domain_mutex);
static struct irq_domain *irq_default_domain;
static int irq_domain_alloc_irqs_locked(struct irq_domain *domain, int irq_base,
unsigned int nr_irqs, int node, void *arg,
bool realloc, const struct irq_affinity_desc *affinity);
static void irq_domain_check_hierarchy(struct irq_domain *domain);
struct irqchip_fwid {
......@@ -682,7 +685,7 @@ unsigned int irq_create_direct_mapping(struct irq_domain *domain)
EXPORT_SYMBOL_GPL(irq_create_direct_mapping);
#endif
static unsigned int __irq_create_mapping_affinity(struct irq_domain *domain,
static unsigned int irq_create_mapping_affinity_locked(struct irq_domain *domain,
irq_hw_number_t hwirq,
const struct irq_affinity_desc *affinity)
{
......@@ -699,7 +702,7 @@ static unsigned int __irq_create_mapping_affinity(struct irq_domain *domain,
return 0;
}
if (irq_domain_associate(domain, virq, hwirq)) {
if (irq_domain_associate_locked(domain, virq, hwirq)) {
irq_free_desc(virq);
return 0;
}
......@@ -735,14 +738,20 @@ unsigned int irq_create_mapping_affinity(struct irq_domain *domain,
return 0;
}
mutex_lock(&irq_domain_mutex);
/* Check if mapping already exists */
virq = irq_find_mapping(domain, hwirq);
if (virq) {
pr_debug("existing mapping on virq %d\n", virq);
return virq;
goto out;
}
return __irq_create_mapping_affinity(domain, hwirq, affinity);
virq = irq_create_mapping_affinity_locked(domain, hwirq, affinity);
out:
mutex_unlock(&irq_domain_mutex);
return virq;
}
EXPORT_SYMBOL_GPL(irq_create_mapping_affinity);
......@@ -809,6 +818,8 @@ 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_domain_mutex);
/*
* If we've already configured this interrupt,
* don't do it again, or hell will break loose.
......@@ -821,7 +832,7 @@ 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
......@@ -829,35 +840,45 @@ 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;
if (!irq_data) {
virq = 0;
goto out;
}
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;
virq = 0;
goto out;
}
if (irq_domain_is_hierarchy(domain)) {
virq = irq_domain_alloc_irqs(domain, 1, NUMA_NO_NODE, fwspec);
if (virq <= 0)
return 0;
virq = irq_domain_alloc_irqs_locked(domain, -1, 1, NUMA_NO_NODE,
fwspec, false, NULL);
if (virq <= 0) {
virq = 0;
goto out;
}
} else {
/* Create mapping */
virq = __irq_create_mapping_affinity(domain, hwirq, NULL);
virq = irq_create_mapping_affinity_locked(domain, hwirq, NULL);
if (!virq)
return virq;
goto out;
}
irq_data = irq_get_irq_data(virq);
if (WARN_ON(!irq_data))
return 0;
if (WARN_ON(!irq_data)) {
virq = 0;
goto out;
}
/* Store trigger type */
irqd_set_trigger_type(irq_data, type);
out:
mutex_unlock(&irq_domain_mutex);
return virq;
}
......@@ -1888,6 +1909,13 @@ void irq_domain_set_info(struct irq_domain *domain, unsigned int virq,
irq_set_handler_data(virq, handler_data);
}
static int irq_domain_alloc_irqs_locked(struct irq_domain *domain, int irq_base,
unsigned int nr_irqs, int node, void *arg,
bool realloc, const struct irq_affinity_desc *affinity)
{
return -EINVAL;
}
static void irq_domain_check_hierarchy(struct irq_domain *domain)
{
}
......
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