From: SeongJae Park sjpark@amazon.de
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
--- drivers/block/xen-blkback/xenbus.c | 3 ++- drivers/net/xen-netback/xenbus.c | 2 +- drivers/xen/xen-pciback/xenbus.c | 2 +- drivers/xen/xenbus/xenbus_client.c | 9 +++++++-- drivers/xen/xenbus/xenbus_probe.c | 2 +- include/xen/xenbus.h | 6 +++++- 6 files changed, 17 insertions(+), 7 deletions(-)
--- a/drivers/block/xen-blkback/xenbus.c +++ b/drivers/block/xen-blkback/xenbus.c @@ -651,7 +651,8 @@ static int xen_blkbk_probe(struct xenbus /* setup back pointer */ be->blkif->be = be;
- err = xenbus_watch_pathfmt(dev, &be->backend_watch, backend_changed, + err = xenbus_watch_pathfmt(dev, &be->backend_watch, NULL, + backend_changed, "%s/%s", dev->nodename, "physical-device"); if (err) goto fail; --- a/drivers/net/xen-netback/xenbus.c +++ b/drivers/net/xen-netback/xenbus.c @@ -1043,7 +1043,7 @@ static void connect(struct backend_info xenvif_carrier_on(be->vif);
unregister_hotplug_status_watch(be); - err = xenbus_watch_pathfmt(dev, &be->hotplug_status_watch, + err = xenbus_watch_pathfmt(dev, &be->hotplug_status_watch, NULL, hotplug_status_changed, "%s/%s", dev->nodename, "hotplug-status"); if (!err) --- a/drivers/xen/xen-pciback/xenbus.c +++ b/drivers/xen/xen-pciback/xenbus.c @@ -688,7 +688,7 @@ static int xen_pcibk_xenbus_probe(struct
/* watch the backend node for backend configuration information */ err = xenbus_watch_path(dev, dev->nodename, &pdev->be_watch, - xen_pcibk_be_watch); + NULL, xen_pcibk_be_watch); if (err) goto out;
--- a/drivers/xen/xenbus/xenbus_client.c +++ b/drivers/xen/xenbus/xenbus_client.c @@ -114,19 +114,22 @@ 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); } @@ -153,6 +156,8 @@ 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, ...) @@ -169,7 +174,7 @@ int xenbus_watch_pathfmt(struct xenbus_d 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); --- a/drivers/xen/xenbus/xenbus_probe.c +++ b/drivers/xen/xenbus/xenbus_probe.c @@ -136,7 +136,7 @@ static int watch_otherend(struct xenbus_ 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"); }
--- a/include/xen/xenbus.h +++ b/include/xen/xenbus.h @@ -199,10 +199,14 @@ void xenbus_probe(struct work_struct *);
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 *)); -__printf(4, 5) +__printf(5, 6) 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, ...);