5 files changed, 42 insertions, 29 deletions

diff --git a/drivers/xen/xenbus/Makefile b/drivers/xen/xenbus/Makefile
index 0c7532110815..b0d69602214e 100644
--- a/drivers/xen/xenbus/Makefile
+++ b/drivers/xen/xenbus/Makefile
@@ -1,15 +1,13 @@
 # SPDX-License-Identifier: GPL-2.0
 obj-y	+= xenbus.o
-obj-y	+= xenbus_dev_frontend.o
 
-xenbus-objs =
-xenbus-objs += xenbus_client.o
-xenbus-objs += xenbus_comms.o
-xenbus-objs += xenbus_xs.o
-xenbus-objs += xenbus_probe.o
+xenbus-y := xenbus_client.o
+xenbus-y += xenbus_comms.o
+xenbus-y += xenbus_xs.o
+xenbus-y += xenbus_probe.o
 
-xenbus-be-objs-$(CONFIG_XEN_BACKEND) += xenbus_probe_backend.o
-xenbus-objs += $(xenbus-be-objs-y)
+xenbus-$(CONFIG_XEN_BACKEND) += xenbus_probe_backend.o
 
+obj-y	+= xenbus_dev_frontend.o
 obj-$(CONFIG_XEN_BACKEND) += xenbus_dev_backend.o
 obj-$(CONFIG_XEN_XENBUS_FRONTEND) += xenbus_probe_frontend.o
diff --git a/drivers/xen/xenbus/xenbus.h b/drivers/xen/xenbus/xenbus.h
index 2754bdfadcb8..13821e7e825e 100644
--- a/drivers/xen/xenbus/xenbus.h
+++ b/drivers/xen/xenbus/xenbus.h
@@ -104,7 +104,7 @@ void xb_deinit_comms(void);
 int xs_watch_msg(struct xs_watch_event *event);
 void xs_request_exit(struct xb_req_data *req);
 
-int xenbus_match(struct device *_dev, struct device_driver *_drv);
+int xenbus_match(struct device *_dev, const struct device_driver *_drv);
 int xenbus_dev_probe(struct device *_dev);
 void xenbus_dev_remove(struct device *_dev);
 int xenbus_register_driver_common(struct xenbus_driver *drv,
diff --git a/drivers/xen/xenbus/xenbus_dev_frontend.c b/drivers/xen/xenbus/xenbus_dev_frontend.c
index 6f56640092a9..46f8916597e5 100644
--- a/drivers/xen/xenbus/xenbus_dev_frontend.c
+++ b/drivers/xen/xenbus/xenbus_dev_frontend.c
@@ -700,7 +700,6 @@ const struct file_operations xen_xenbus_fops = {
 	.open = xenbus_file_open,
 	.release = xenbus_file_release,
 	.poll = xenbus_file_poll,
-	.llseek = no_llseek,
 };
 EXPORT_SYMBOL_GPL(xen_xenbus_fops);
 
diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c
index 3205e5d724c8..6d32ffb01136 100644
--- a/drivers/xen/xenbus/xenbus_probe.c
+++ b/drivers/xen/xenbus/xenbus_probe.c
@@ -65,13 +65,17 @@
 #include "xenbus.h"
 
 
-static int xs_init_irq;
+static int xs_init_irq = -1;
 int xen_store_evtchn;
 EXPORT_SYMBOL_GPL(xen_store_evtchn);
 
 struct xenstore_domain_interface *xen_store_interface;
 EXPORT_SYMBOL_GPL(xen_store_interface);
 
+#define XS_INTERFACE_READY \
+	((xen_store_interface != NULL) && \
+	 (xen_store_interface->connection == XENSTORE_CONNECTED))
+
 enum xenstore_init xen_store_domain_type;
 EXPORT_SYMBOL_GPL(xen_store_domain_type);
 
@@ -90,9 +94,9 @@ match_device(const struct xenbus_device_id *arr, struct xenbus_device *dev)
 	return NULL;
 }
 
-int xenbus_match(struct device *_dev, struct device_driver *_drv)
+int xenbus_match(struct device *_dev, const struct device_driver *_drv)
 {
-	struct xenbus_driver *drv = to_xenbus_driver(_drv);
+	const struct xenbus_driver *drv = to_xenbus_driver(_drv);
 
 	if (!drv->ids)
 		return 0;
@@ -309,7 +313,7 @@ int xenbus_dev_probe(struct device *_dev)
 	if (err) {
 		dev_warn(&dev->dev, "watch_otherend on %s failed.\n",
 		       dev->nodename);
-		return err;
+		goto fail_remove;
 	}
 
 	dev->spurious_threshold = 1;
@@ -318,6 +322,12 @@ int xenbus_dev_probe(struct device *_dev)
 			 dev->nodename);
 
 	return 0;
+fail_remove:
+	if (drv->remove) {
+		down(&dev->reclaim_sem);
+		drv->remove(dev);
+		up(&dev->reclaim_sem);
+	}
 fail_put:
 	module_put(drv->driver.owner);
 fail:
@@ -751,19 +761,19 @@ static void xenbus_probe(void)
 {
 	xenstored_ready = 1;
 
-	if (!xen_store_interface) {
+	if (!xen_store_interface)
 		xen_store_interface = memremap(xen_store_gfn << XEN_PAGE_SHIFT,
 					       XEN_PAGE_SIZE, MEMREMAP_WB);
-		/*
-		 * Now it is safe to free the IRQ used for xenstore late
-		 * initialization. No need to unbind: it is about to be
-		 * bound again from xb_init_comms. Note that calling
-		 * unbind_from_irqhandler now would result in xen_evtchn_close()
-		 * being called and the event channel not being enabled again
-		 * afterwards, resulting in missed event notifications.
-		 */
+	/*
+	 * Now it is safe to free the IRQ used for xenstore late
+	 * initialization. No need to unbind: it is about to be
+	 * bound again from xb_init_comms. Note that calling
+	 * unbind_from_irqhandler now would result in xen_evtchn_close()
+	 * being called and the event channel not being enabled again
+	 * afterwards, resulting in missed event notifications.
+	 */
+	if (xs_init_irq >= 0)
 		free_irq(xs_init_irq, &xb_waitq);
-	}
 
 	/*
 	 * In the HVM case, xenbus_init() deferred its call to
@@ -822,7 +832,7 @@ static int __init xenbus_probe_initcall(void)
 	if (xen_store_domain_type == XS_PV ||
 	    (xen_store_domain_type == XS_HVM &&
 	     !xs_hvm_defer_init_for_callback() &&
-	     xen_store_interface != NULL))
+	     XS_INTERFACE_READY))
 		xenbus_probe();
 
 	/*
@@ -831,7 +841,7 @@ static int __init xenbus_probe_initcall(void)
 	 * started, then probe.  It will be triggered when communication
 	 * starts happening, by waiting on xb_waitq.
 	 */
-	if (xen_store_domain_type == XS_LOCAL || xen_store_interface == NULL) {
+	if (xen_store_domain_type == XS_LOCAL || !XS_INTERFACE_READY) {
 		struct task_struct *probe_task;
 
 		probe_task = kthread_run(xenbus_probe_thread, NULL,
@@ -1014,6 +1024,12 @@ static int __init xenbus_init(void)
 			xen_store_interface =
 				memremap(xen_store_gfn << XEN_PAGE_SHIFT,
 					 XEN_PAGE_SIZE, MEMREMAP_WB);
+			if (!xen_store_interface) {
+				pr_err("%s: cannot map HVM_PARAM_STORE_PFN=%llx\n",
+				       __func__, v);
+				err = -EINVAL;
+				goto out_error;
+			}
 			if (xen_store_interface->connection != XENSTORE_CONNECTED)
 				wait = true;
 		}
diff --git a/drivers/xen/xenbus/xenbus_xs.c b/drivers/xen/xenbus/xenbus_xs.c
index 028a182bcc9e..d32c726f7a12 100644
--- a/drivers/xen/xenbus/xenbus_xs.c
+++ b/drivers/xen/xenbus/xenbus_xs.c
@@ -427,12 +427,12 @@ char **xenbus_directory(struct xenbus_transaction t,
 
 	path = join(dir, node);
 	if (IS_ERR(path))
-		return (char **)path;
+		return ERR_CAST(path);
 
 	strings = xs_single(t, XS_DIRECTORY, path, &len);
 	kfree(path);
 	if (IS_ERR(strings))
-		return (char **)strings;
+		return ERR_CAST(strings);
 
 	return split(strings, len, num);
 }
@@ -465,7 +465,7 @@ void *xenbus_read(struct xenbus_transaction t,
 
 	path = join(dir, node);
 	if (IS_ERR(path))
-		return (void *)path;
+		return ERR_CAST(path);
 
 	ret = xs_single(t, XS_READ, path, len);
 	kfree(path);