irqdomain/treewide: Free firmware node after domain removal

Commit 711419e504eb ("irqdomain: Add the missing assignment of
domain->fwnode for named fwnode") unintentionally caused a dangling pointer
page fault issue on firmware nodes that were freed after IRQ domain
allocation. Commit e3beca48a45b fixed that dangling pointer issue by only
freeing the firmware node after an IRQ domain allocation failure. That fix
no longer frees the firmware node immediately, but leaves the firmware node
allocated after the domain is removed.

The firmware node must be kept around through irq_domain_remove, but should be
freed it afterwards.

Add the missing free operations after domain removal where where appropriate.

Fixes: e3beca48a45b ("irqdomain/treewide: Keep firmware node unconditionally allocated")
Signed-off-by: Jon Derrick <jonathan.derrick@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>	# drivers/pci
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/1595363169-7157-1-git-send-email-jonathan.derrick@intel.com

5 files changed, 25 insertions, 0 deletions

diff --git a/arch/mips/pci/pci-xtalk-bridge.c b/arch/mips/pci/pci-xtalk-bridge.c
index 5958217861b8..9b3cc775c55e 100644
--- a/arch/mips/pci/pci-xtalk-bridge.c
+++ b/arch/mips/pci/pci-xtalk-bridge.c
@@ -728,6 +728,7 @@ err_free_resource:
 	pci_free_resource_list(&host->windows);
 err_remove_domain:
 	irq_domain_remove(domain);
+	irq_domain_free_fwnode(fn);
 	return err;
 }
 
@@ -735,8 +736,10 @@ static int bridge_remove(struct platform_device *pdev)
 {
 	struct pci_bus *bus = platform_get_drvdata(pdev);
 	struct bridge_controller *bc = BRIDGE_CONTROLLER(bus);
+	struct fwnode_handle *fn = bc->domain->fwnode;
 
 	irq_domain_remove(bc->domain);
+	irq_domain_free_fwnode(fn);
 	pci_lock_rescan_remove();
 	pci_stop_root_bus(bus);
 	pci_remove_root_bus(bus);
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 81ffcfbfaef2..21325a4a78b9 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -2335,8 +2335,13 @@ static int mp_irqdomain_create(int ioapic)
 
 static void ioapic_destroy_irqdomain(int idx)
 {
+	struct ioapic_domain_cfg *cfg = &ioapics[idx].irqdomain_cfg;
+	struct fwnode_handle *fn = ioapics[idx].irqdomain->fwnode;
+
 	if (ioapics[idx].irqdomain) {
 		irq_domain_remove(ioapics[idx].irqdomain);
+		if (!cfg->dev)
+			irq_domain_free_fwnode(fn);
 		ioapics[idx].irqdomain = NULL;
 	}
 }
diff --git a/drivers/iommu/intel/irq_remapping.c b/drivers/iommu/intel/irq_remapping.c
index 9564d23d094f..aa096b333a99 100644
--- a/drivers/iommu/intel/irq_remapping.c
+++ b/drivers/iommu/intel/irq_remapping.c
@@ -628,13 +628,21 @@ out_free_table:
 
 static void intel_teardown_irq_remapping(struct intel_iommu *iommu)
 {
+	struct fwnode_handle *fn;
+
 	if (iommu && iommu->ir_table) {
 		if (iommu->ir_msi_domain) {
+			fn = iommu->ir_msi_domain->fwnode;
+
 			irq_domain_remove(iommu->ir_msi_domain);
+			irq_domain_free_fwnode(fn);
 			iommu->ir_msi_domain = NULL;
 		}
 		if (iommu->ir_domain) {
+			fn = iommu->ir_domain->fwnode;
+
 			irq_domain_remove(iommu->ir_domain);
+			irq_domain_free_fwnode(fn);
 			iommu->ir_domain = NULL;
 		}
 		free_pages((unsigned long)iommu->ir_table->base,
diff --git a/drivers/mfd/ioc3.c b/drivers/mfd/ioc3.c
index 74cee7cb0afc..d939ccc46509 100644
--- a/drivers/mfd/ioc3.c
+++ b/drivers/mfd/ioc3.c
@@ -616,7 +616,10 @@ static int ioc3_mfd_probe(struct pci_dev *pdev,
 		/* Remove all already added MFD devices */
 		mfd_remove_devices(&ipd->pdev->dev);
 		if (ipd->domain) {
+			struct fwnode_handle *fn = ipd->domain->fwnode;
+
 			irq_domain_remove(ipd->domain);
+			irq_domain_free_fwnode(fn);
 			free_irq(ipd->domain_irq, (void *)ipd);
 		}
 		pci_iounmap(pdev, regs);
@@ -643,7 +646,10 @@ static void ioc3_mfd_remove(struct pci_dev *pdev)
 	/* Release resources */
 	mfd_remove_devices(&ipd->pdev->dev);
 	if (ipd->domain) {
+		struct fwnode_handle *fn = ipd->domain->fwnode;
+
 		irq_domain_remove(ipd->domain);
+		irq_domain_free_fwnode(fn);
 		free_irq(ipd->domain_irq, (void *)ipd);
 	}
 	pci_iounmap(pdev, ipd->regs);
diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c
index 9a64cf90c291..ebec0a6e77ed 100644
--- a/drivers/pci/controller/vmd.c
+++ b/drivers/pci/controller/vmd.c
@@ -560,6 +560,7 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
 	if (!vmd->bus) {
 		pci_free_resource_list(&resources);
 		irq_domain_remove(vmd->irq_domain);
+		irq_domain_free_fwnode(fn);
 		return -ENODEV;
 	}
 
@@ -673,6 +674,7 @@ static void vmd_cleanup_srcu(struct vmd_dev *vmd)
 static void vmd_remove(struct pci_dev *dev)
 {
 	struct vmd_dev *vmd = pci_get_drvdata(dev);
+	struct fwnode_handle *fn = vmd->irq_domain->fwnode;
 
 	sysfs_remove_link(&vmd->dev->dev.kobj, "domain");
 	pci_stop_root_bus(vmd->bus);
@@ -680,6 +682,7 @@ static void vmd_remove(struct pci_dev *dev)
 	vmd_cleanup_srcu(vmd);
 	vmd_detach_resources(vmd);
 	irq_domain_remove(vmd->irq_domain);
+	irq_domain_free_fwnode(fn);
 }
 
 #ifdef CONFIG_PM_SLEEP