[PATCH] genirq/msi: Fix unpaired calls in msi

From: Bixuan Cui
Date: Mon May 17 2021 - 22:08:07 EST


There are unpaired calls in the msi:

msi_domain_alloc_irqs() {
...
__irq_domain_alloc_irqs()
...
irq_domain_activate_irq()
}

msi_domain_free_irqs() {
...
irq_domain_free_irqs()
}

When msi_domain_alloc_irqs() and msi_domain_free_irqs() are called in
pairs, the irq_domain_deactivate_irq() is missing calls.

This problem occurs during PCI initialization.After pci_msi_setup_msi_irqs
is executed (invoke irq_domain_activate_irq to initialize the MSI irq),
error_cleanup_irqs() of pcie_port_device_register() is executed.
As follows:

pcie_port_device_register() {
...

error_cleanup_irqs:
pci_free_irq_vectors(dev);
}

Invoking Procedure:
pcie_port_device_register
-> goto error_cleanup_irqs
-> pci_free_irq_vectors(dev);
pci_disable_msi
free_msi_irqs
pci_msi_teardown_msi_irqs
msi_domain_free_irqs // no deactivate before free
irq_domain_free_irqs

Signed-off-by: Bixuan Cui <cuibixuan@xxxxxxxxxx>
---
kernel/irq/msi.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c
index c41965e348b5..8828d4863c5d 100644
--- a/kernel/irq/msi.c
+++ b/kernel/irq/msi.c
@@ -476,11 +476,6 @@ int __msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev,
return 0;

cleanup:
- for_each_msi_vector(desc, i, dev) {
- irq_data = irq_domain_get_irq_data(domain, i);
- if (irqd_is_activated(irq_data))
- irq_domain_deactivate_irq(irq_data);
- }
msi_domain_free_irqs(domain, dev);
return ret;
}
@@ -506,6 +501,14 @@ int msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev,
void __msi_domain_free_irqs(struct irq_domain *domain, struct device *dev)
{
struct msi_desc *desc;
+ struct irq_data *irq_data;
+ int i;
+
+ for_each_msi_vector(desc, i, dev) {
+ irq_data = irq_domain_get_irq_data(domain, i);
+ if (irqd_is_activated(irq_data))
+ irq_domain_deactivate_irq(irq_data);
+ }

for_each_msi_entry(desc, dev) {
/*
--
2.17.1