irqdomain/treewide: Free firmware node after domain removal

commit ec0160891e387f4771f953b888b1fe951398e5d9 upstream.

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: NJon Derrick <jonathan.derrick@intel.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NAndy 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.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

arch/x86/kernel/apic/io_apic.c

@@ -2346,8 +2346,13 @@ 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;
 	}
 }

drivers/iommu/intel_irq_remapping.c

@@ -601,13 +601,21 @@ static int intel_setup_irq_remapping(struct intel_iommu *iommu)
 
 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,

drivers/pci/controller/vmd.c

@@ -718,6 +718,7 @@ 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;
 	}
 
@@ -820,6 +821,7 @@ 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);
@@ -828,6 +830,7 @@ static void vmd_remove(struct pci_dev *dev)
 	vmd_teardown_dma_ops(vmd);
 	vmd_detach_resources(vmd);
 	irq_domain_remove(vmd->irq_domain);
+	irq_domain_free_fwnode(fn);
 }
 
 #ifdef CONFIG_PM_SLEEP