Commit 578c1bb9 authored by Juergen Gross's avatar Juergen Gross Committed by Boris Ostrovsky
Browse files

xen/xenbus: let xenbus_map_ring_valloc() return errno values only 



Today xenbus_map_ring_valloc() can return either a negative errno
value (-ENOMEM or -EINVAL) or a grant status value. This is a mess as
e.g -ENOMEM and GNTST_eagain have the same numeric value.

Fix that by turning all grant mapping errors into -ENOENT. This is
no problem as all callers of xenbus_map_ring_valloc() only use the
return value to print an error message, and in case of mapping errors
the grant status value has already been printed by __xenbus_map_ring()
before.

Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
Reviewed-by: default avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
Link: https://lore.kernel.org/r/20200701121638.19840-3-jgross@suse.com


Signed-off-by: default avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
parent 3848e4e0

drivers/xen/xenbus/xenbus_client.c

+6 −16
Original line number Diff line number Diff line
@@ -456,8 +456,7 @@ EXPORT_SYMBOL_GPL(xenbus_free_evtchn); 
 * Map @nr_grefs pages of memory into this domain from another

 * domain's grant table.  xenbus_map_ring_valloc allocates @nr_grefs

 * pages of virtual address space, maps the pages to that address, and

 * sets *vaddr to that address.  Returns 0 on success, and GNTST_*

 * (see xen/include/interface/grant_table.h) or -ENOMEM / -EINVAL on

 * sets *vaddr to that address.  Returns 0 on success, and -errno on

 * error. If an error is returned, device will switch to

 * XenbusStateClosing and the error message will be saved in XenStore.

 */
@@ -477,18 +476,11 @@ int xenbus_map_ring_valloc(struct xenbus_device *dev, grant_ref_t *gnt_refs, 
		return -ENOMEM;



	info->node = kzalloc(sizeof(*info->node), GFP_KERNEL);

	if (!info->node) {

	if (!info->node)

		err = -ENOMEM;

		goto out;

	}



	else

		err = ring_ops->map(dev, info, gnt_refs, nr_grefs, vaddr);



	/* Some hypervisors are buggy and can return 1. */

	if (err > 0)

		err = GNTST_general_error;



 out:

	kfree(info->node);

	kfree(info);

	return err;
@@ -507,7 +499,6 @@ static int __xenbus_map_ring(struct xenbus_device *dev, 
			     bool *leaked)

{

	int i, j;

	int err = GNTST_okay;



	if (nr_grefs > XENBUS_MAX_RING_GRANTS)

		return -EINVAL;
@@ -522,7 +513,6 @@ static int __xenbus_map_ring(struct xenbus_device *dev, 


	for (i = 0; i < nr_grefs; i++) {

		if (info->map[i].status != GNTST_okay) {

			err = info->map[i].status;

			xenbus_dev_fatal(dev, info->map[i].status,

					 "mapping in shared page %d from domain %d",

					 gnt_refs[i], dev->otherend_id);
@@ -531,7 +521,7 @@ static int __xenbus_map_ring(struct xenbus_device *dev, 
			handles[i] = info->map[i].handle;

	}



	return GNTST_okay;

	return 0;



 fail:

	for (i = j = 0; i < nr_grefs; i++) {
@@ -554,7 +544,7 @@ static int __xenbus_map_ring(struct xenbus_device *dev, 
		}

	}



	return err;

	return -ENOENT;

}



/**

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