Messages in this thread Patch in this message | | | From | Johan Hovold <> | Subject | [PATCH v2 2/4] irqdomain: Fix mapping-creation race | Date | Thu, 1 Sep 2022 16:28:14 +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.
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> Link: https://lore.kernel.org/r/YuJXMHoT4ijUxnRb@hovoldconsulting.com Signed-off-by: Johan Hovold <johan+linaro@kernel.org> --- include/linux/irqdomain.h | 2 ++ kernel/irq/irqdomain.c | 33 ++++++++++++++++++++++++--------- 2 files changed, 26 insertions(+), 9 deletions(-)
diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h index 00d577f90883..8df9b9586e29 100644 --- a/include/linux/irqdomain.h +++ b/include/linux/irqdomain.h @@ -144,6 +144,7 @@ struct irq_domain_chip_generic; * core code. * @flags: host per irq_domain flags * @mapcount: The number of mapped interrupts + * @map_mutex: Mapping lock * * Optional elements * @fwnode: Pointer to firmware node associated with the irq_domain. Pretty easy @@ -168,6 +169,7 @@ struct irq_domain { void *host_data; unsigned int flags; unsigned int mapcount; + struct mutex map_mutex; /* Optional data */ struct fwnode_handle *fwnode; diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c index 24ddd8d9b597..1af1d141e165 100644 --- a/kernel/irq/irqdomain.c +++ b/kernel/irq/irqdomain.c @@ -215,6 +215,7 @@ struct irq_domain *__irq_domain_add(struct fwnode_handle *fwnode, unsigned int s /* Fill structure */ INIT_RADIX_TREE(&domain->revmap_tree, GFP_KERNEL); mutex_init(&domain->revmap_mutex); + mutex_init(&domain->map_mutex); domain->ops = ops; domain->host_data = host_data; domain->hwirq_max = hwirq_max; @@ -721,14 +722,20 @@ unsigned int irq_create_mapping_affinity(struct irq_domain *domain, return 0; } + mutex_lock(&domain->map_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(domain, hwirq, affinity); +out: + mutex_unlock(&domain->map_mutex); + + return virq; } EXPORT_SYMBOL_GPL(irq_create_mapping_affinity); @@ -795,6 +802,8 @@ 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(&domain->map_mutex); + /* * If we've already configured this interrupt, * don't do it again, or hell will break loose. @@ -807,7 +816,7 @@ 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 @@ -816,26 +825,26 @@ 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_affinity(domain, hwirq, NULL); if (!virq) - return virq; + goto err; } irq_data = irq_get_irq_data(virq); @@ -844,13 +853,19 @@ 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(&domain->map_mutex); return virq; +err: + mutex_unlock(&domain->map_mutex); + + return 0; } EXPORT_SYMBOL_GPL(irq_create_fwspec_mapping); -- 2.35.1
| |