xen/xenbus: Add 'will_handle' callback support in xenbus_watch_path()

commit 2e85d32b1c865bec703ce0c962221a5e955c52c2 upstream.

Some code does not directly make 'xenbus_watch' object and call
'register_xenbus_watch()' but use 'xenbus_watch_path()' instead.  This
commit adds support of 'will_handle' callback in the
'xenbus_watch_path()' and it's wrapper, 'xenbus_watch_pathfmt()'.

This is part of XSA-349

Cc: stable@vger.kernel.org
Signed-off-by: SeongJae Park <sjpark@amazon.de>
Reported-by: Michael Kurth <mku@amazon.de>
Reported-by: Pawel Wieczorkiewicz <wipawel@amazon.de>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
SeongJae Park
2020-12-14 10:04:18 +01:00
committed by Greg Kroah-Hartman
parent b4898bdd20
commit 9ae6d2f4ca
6 changed files with 17 additions and 7 deletions

View File

@@ -127,19 +127,22 @@ EXPORT_SYMBOL_GPL(xenbus_strstate);
*/
int xenbus_watch_path(struct xenbus_device *dev, const char *path,
struct xenbus_watch *watch,
bool (*will_handle)(struct xenbus_watch *,
const char *, const char *),
void (*callback)(struct xenbus_watch *,
const char *, const char *))
{
int err;
watch->node = path;
watch->will_handle = NULL;
watch->will_handle = will_handle;
watch->callback = callback;
err = register_xenbus_watch(watch);
if (err) {
watch->node = NULL;
watch->will_handle = NULL;
watch->callback = NULL;
xenbus_dev_fatal(dev, err, "adding watch on %s", path);
}
@@ -166,6 +169,8 @@ EXPORT_SYMBOL_GPL(xenbus_watch_path);
*/
int xenbus_watch_pathfmt(struct xenbus_device *dev,
struct xenbus_watch *watch,
bool (*will_handle)(struct xenbus_watch *,
const char *, const char *),
void (*callback)(struct xenbus_watch *,
const char *, const char *),
const char *pathfmt, ...)
@@ -182,7 +187,7 @@ int xenbus_watch_pathfmt(struct xenbus_device *dev,
xenbus_dev_fatal(dev, -ENOMEM, "allocating path for watch");
return -ENOMEM;
}
err = xenbus_watch_path(dev, path, watch, callback);
err = xenbus_watch_path(dev, path, watch, will_handle, callback);
if (err)
kfree(path);

View File

@@ -136,7 +136,7 @@ static int watch_otherend(struct xenbus_device *dev)
container_of(dev->dev.bus, struct xen_bus_type, bus);
return xenbus_watch_pathfmt(dev, &dev->otherend_watch,
bus->otherend_changed,
NULL, bus->otherend_changed,
"%s/%s", dev->otherend, "state");
}