1 files changed, 31 insertions, 13 deletions

diff --git a/drivers/iommu/iommufd/fault.c b/drivers/iommu/iommufd/fault.c
index 1fe804e28a86..d9a937450e55 100644
--- a/drivers/iommu/iommufd/fault.c
+++ b/drivers/iommu/iommufd/fault.c
@@ -103,15 +103,23 @@ static void iommufd_auto_response_faults(struct iommufd_hw_pagetable *hwpt,
 {
 	struct iommufd_fault *fault = hwpt->fault;
 	struct iopf_group *group, *next;
+	struct list_head free_list;
 	unsigned long index;
 
 	if (!fault)
 		return;
+	INIT_LIST_HEAD(&free_list);
 
 	mutex_lock(&fault->mutex);
+	spin_lock(&fault->lock);
 	list_for_each_entry_safe(group, next, &fault->deliver, node) {
 		if (group->attach_handle != &handle->handle)
 			continue;
+		list_move(&group->node, &free_list);
+	}
+	spin_unlock(&fault->lock);
+
+	list_for_each_entry_safe(group, next, &free_list, node) {
 		list_del(&group->node);
 		iopf_group_response(group, IOMMU_PAGE_RESP_INVALID);
 		iopf_free_group(group);
@@ -213,6 +221,7 @@ void iommufd_fault_destroy(struct iommufd_object *obj)
 {
 	struct iommufd_fault *fault = container_of(obj, struct iommufd_fault, obj);
 	struct iopf_group *group, *next;
+	unsigned long index;
 
 	/*
 	 * The iommufd object's reference count is zero at this point.
@@ -225,6 +234,13 @@ void iommufd_fault_destroy(struct iommufd_object *obj)
 		iopf_group_response(group, IOMMU_PAGE_RESP_INVALID);
 		iopf_free_group(group);
 	}
+	xa_for_each(&fault->response, index, group) {
+		xa_erase(&fault->response, index);
+		iopf_group_response(group, IOMMU_PAGE_RESP_INVALID);
+		iopf_free_group(group);
+	}
+	xa_destroy(&fault->response);
+	mutex_destroy(&fault->mutex);
 }
 
 static void iommufd_compose_fault_message(struct iommu_fault *fault,
@@ -247,7 +263,7 @@ static ssize_t iommufd_fault_fops_read(struct file *filep, char __user *buf,
 {
 	size_t fault_size = sizeof(struct iommu_hwpt_pgfault);
 	struct iommufd_fault *fault = filep->private_data;
-	struct iommu_hwpt_pgfault data;
+	struct iommu_hwpt_pgfault data = {};
 	struct iommufd_device *idev;
 	struct iopf_group *group;
 	struct iopf_fault *iopf;
@@ -258,17 +274,19 @@ static ssize_t iommufd_fault_fops_read(struct file *filep, char __user *buf,
 		return -ESPIPE;
 
 	mutex_lock(&fault->mutex);
-	while (!list_empty(&fault->deliver) && count > done) {
-		group = list_first_entry(&fault->deliver,
-					 struct iopf_group, node);
-
-		if (group->fault_count * fault_size > count - done)
+	while ((group = iommufd_fault_deliver_fetch(fault))) {
+		if (done >= count ||
+		    group->fault_count * fault_size > count - done) {
+			iommufd_fault_deliver_restore(fault, group);
 			break;
+		}
 
 		rc = xa_alloc(&fault->response, &group->cookie, group,
 			      xa_limit_32b, GFP_KERNEL);
-		if (rc)
+		if (rc) {
+			iommufd_fault_deliver_restore(fault, group);
 			break;
+		}
 
 		idev = to_iommufd_handle(group->attach_handle)->idev;
 		list_for_each_entry(iopf, &group->faults, list) {
@@ -277,13 +295,12 @@ static ssize_t iommufd_fault_fops_read(struct file *filep, char __user *buf,
 						      group->cookie);
 			if (copy_to_user(buf + done, &data, fault_size)) {
 				xa_erase(&fault->response, group->cookie);
+				iommufd_fault_deliver_restore(fault, group);
 				rc = -EFAULT;
 				break;
 			}
 			done += fault_size;
 		}
-
-		list_del(&group->node);
 	}
 	mutex_unlock(&fault->mutex);
 
@@ -341,10 +358,10 @@ static __poll_t iommufd_fault_fops_poll(struct file *filep,
 	__poll_t pollflags = EPOLLOUT;
 
 	poll_wait(filep, &fault->wait_queue, wait);
-	mutex_lock(&fault->mutex);
+	spin_lock(&fault->lock);
 	if (!list_empty(&fault->deliver))
 		pollflags |= EPOLLIN | EPOLLRDNORM;
-	mutex_unlock(&fault->mutex);
+	spin_unlock(&fault->lock);
 
 	return pollflags;
 }
@@ -386,6 +403,7 @@ int iommufd_fault_alloc(struct iommufd_ucmd *ucmd)
 	INIT_LIST_HEAD(&fault->deliver);
 	xa_init_flags(&fault->response, XA_FLAGS_ALLOC1);
 	mutex_init(&fault->mutex);
+	spin_lock_init(&fault->lock);
 	init_waitqueue_head(&fault->wait_queue);
 
 	filep = anon_inode_getfile("[iommufd-pgfault]", &iommufd_fault_fops,
@@ -434,9 +452,9 @@ int iommufd_fault_iopf_handler(struct iopf_group *group)
 	hwpt = group->attach_handle->domain->fault_data;
 	fault = hwpt->fault;
 
-	mutex_lock(&fault->mutex);
+	spin_lock(&fault->lock);
 	list_add_tail(&group->node, &fault->deliver);
-	mutex_unlock(&fault->mutex);
+	spin_unlock(&fault->lock);
 
 	wake_up_interruptible(&fault->wait_queue);