A set of updates for the interrupt susbsystem:

- Prevent possible NULL pointer derefences in irq_data_get_affinity_mask()
     and irq_domain_create_hierarchy().
 
   - Take the per device MSI lock before invoking code which relies
     on it being hold.
 
   - Make sure that MSI descriptors are unreferenced before freeing
     them. This was overlooked when the platform MSI code was converted to
     use core infrastructure and results in a fals positive warning.
 
   - Remove dead code in the MSI subsystem.
 
   - Clarify the documentation for pci_msix_free_irq().
 
   - More kobj_type constification.
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Merge tag 'irq-urgent-2023-03-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull irq updates from Thomas Gleixner:
 "A set of updates for the interrupt susbsystem:

   - Prevent possible NULL pointer derefences in
     irq_data_get_affinity_mask() and irq_domain_create_hierarchy()

   - Take the per device MSI lock before invoking code which relies on
     it being hold

   - Make sure that MSI descriptors are unreferenced before freeing
     them. This was overlooked when the platform MSI code was converted
     to use core infrastructure and results in a fals positive warning

   - Remove dead code in the MSI subsystem

   - Clarify the documentation for pci_msix_free_irq()

   - More kobj_type constification"

* tag 'irq-urgent-2023-03-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq/msi, platform-msi: Ensure that MSI descriptors are unreferenced
  genirq/msi: Drop dead domain name assignment
  irqdomain: Add missing NULL pointer check in irq_domain_create_hierarchy()
  genirq/irqdesc: Make kobj_type structures constant
  PCI/MSI: Clarify usage of pci_msix_free_irq()
  genirq/msi: Take the per-device MSI lock before validating the control structure
  genirq/ipi: Fix NULL pointer deref in irq_data_get_affinity_mask()

drivers/base/platform-msi.c

@@ -324,6 +324,7 @@ void platform_msi_device_domain_free(struct irq_domain *domain, unsigned int vir
 	struct platform_msi_priv_data *data = domain->host_data;
 
 	msi_lock_descs(data->dev);
+	msi_domain_depopulate_descs(data->dev, virq, nr_irqs);
 	irq_domain_free_irqs_common(domain, virq, nr_irqs);
 	msi_free_msi_descs_range(data->dev, virq, virq + nr_irqs - 1);
 	msi_unlock_descs(data->dev);

drivers/pci/msi/api.c

@@ -163,11 +163,11 @@ EXPORT_SYMBOL_GPL(pci_msix_alloc_irq_at);
 
 /**
  * pci_msix_free_irq - Free an interrupt on a PCI/MSIX interrupt domain
- *		      which was allocated via pci_msix_alloc_irq_at()
  *
  * @dev:	The PCI device to operate on
  * @map:	A struct msi_map describing the interrupt to free
- *		as returned from the allocation function.
+ *
+ * Undo an interrupt vector allocation. Does not disable MSI-X.
  */
 void pci_msix_free_irq(struct pci_dev *dev, struct msi_map map)
 {

include/linux/msi.h

@@ -635,6 +635,8 @@ int msi_domain_prepare_irqs(struct irq_domain *domain, struct device *dev,
 			    int nvec, msi_alloc_info_t *args);
 int msi_domain_populate_irqs(struct irq_domain *domain, struct device *dev,
 			     int virq, int nvec, msi_alloc_info_t *args);
+void msi_domain_depopulate_descs(struct device *dev, int virq, int nvec);
+
 struct irq_domain *
 __platform_msi_create_device_domain(struct device *dev,
 				    unsigned int nvec,

kernel/irq/ipi.c

@@ -188,9 +188,9 @@ EXPORT_SYMBOL_GPL(ipi_get_hwirq);
 static int ipi_send_verify(struct irq_chip *chip, struct irq_data *data,
 			   const struct cpumask *dest, unsigned int cpu)
 {
-	const struct cpumask *ipimask = irq_data_get_affinity_mask(data);
+	const struct cpumask *ipimask;
 
-	if (!chip || !ipimask)
+	if (!chip || !data)
 		return -EINVAL;
 
 	if (!chip->ipi_send_single && !chip->ipi_send_mask)
@@ -199,6 +199,10 @@ static int ipi_send_verify(struct irq_chip *chip, struct irq_data *data,
 	if (cpu >= nr_cpu_ids)
 		return -EINVAL;
 
+	ipimask = irq_data_get_affinity_mask(data);
+	if (!ipimask)
+		return -EINVAL;
+
 	if (dest) {
 		if (!cpumask_subset(dest, ipimask))
 			return -EINVAL;

kernel/irq/irqdesc.c

@@ -277,7 +277,7 @@ static struct attribute *irq_attrs[] = {
 };
 ATTRIBUTE_GROUPS(irq);
 
-static struct kobj_type irq_kobj_type = {
+static const struct kobj_type irq_kobj_type = {
 	.release	= irq_kobj_release,
 	.sysfs_ops	= &kobj_sysfs_ops,
 	.default_groups = irq_groups,
@@ -335,7 +335,7 @@ postcore_initcall(irq_sysfs_init);
 
 #else /* !CONFIG_SYSFS */
 
-static struct kobj_type irq_kobj_type = {
+static const struct kobj_type irq_kobj_type = {
 	.release	= irq_kobj_release,
 };
 

kernel/irq/irqdomain.c

@@ -1147,7 +1147,8 @@ struct irq_domain *irq_domain_create_hierarchy(struct irq_domain *parent,
 		domain = __irq_domain_create(fwnode, 0, ~0, 0, ops, host_data);
 
 	if (domain) {
-		domain->root = parent->root;
+		if (parent)
+			domain->root = parent->root;
 		domain->parent = parent;
 		domain->flags |= flags;
 

kernel/irq/msi.c

@@ -830,11 +830,8 @@ static struct irq_domain *__msi_create_irq_domain(struct fwnode_handle *fwnode,
 	domain = irq_domain_create_hierarchy(parent, flags | IRQ_DOMAIN_FLAG_MSI, 0,
 					     fwnode, &msi_domain_ops, info);
 
-	if (domain) {
-		if (!domain->name && info->chip)
-			domain->name = info->chip->name;
+	if (domain)
 		irq_domain_update_bus_token(domain, info->bus_token);
-	}
 
 	return domain;
 }
@@ -1084,10 +1081,13 @@ int msi_domain_populate_irqs(struct irq_domain *domain, struct device *dev,
 	struct xarray *xa;
 	int ret, virq;
 
-	if (!msi_ctrl_valid(dev, &ctrl))
-		return -EINVAL;
-
 	msi_lock_descs(dev);
+
+	if (!msi_ctrl_valid(dev, &ctrl)) {
+		ret = -EINVAL;
+		goto unlock;
+	}
+
 	ret = msi_domain_add_simple_msi_descs(dev, &ctrl);
 	if (ret)
 		goto unlock;
@@ -1109,14 +1109,35 @@ int msi_domain_populate_irqs(struct irq_domain *domain, struct device *dev,
 	return 0;
 
 fail:
-	for (--virq; virq >= virq_base; virq--)
+	for (--virq; virq >= virq_base; virq--) {
+		msi_domain_depopulate_descs(dev, virq, 1);
 		irq_domain_free_irqs_common(domain, virq, 1);
+	}
 	msi_domain_free_descs(dev, &ctrl);
 unlock:
 	msi_unlock_descs(dev);
 	return ret;
 }
 
+void msi_domain_depopulate_descs(struct device *dev, int virq_base, int nvec)
+{
+	struct msi_ctrl ctrl = {
+		.domid	= MSI_DEFAULT_DOMAIN,
+		.first  = virq_base,
+		.last	= virq_base + nvec - 1,
+	};
+	struct msi_desc *desc;
+	struct xarray *xa;
+	unsigned long idx;
+
+	if (!msi_ctrl_valid(dev, &ctrl))
+		return;
+
+	xa = &dev->msi.data->__domains[ctrl.domid].store;
+	xa_for_each_range(xa, idx, desc, ctrl.first, ctrl.last)
+		desc->irq = 0;
+}
+
 /*
  * Carefully check whether the device can use reservation mode. If
  * reservation mode is enabled then the early activation will assign a