forked from Minki/linux
c4c303c7c5
During repeated kexec boots xenwatch_thread() can crash because xenbus_watch->callback is cleared by xenbus_watch_path() if a node/token combo for a new watch happens to match an already registered watch from an old kernel. In this case xs_watch returns -EEXISTS, then register_xenbus_watch() does not remove the to-be-registered watch from the list of active watches but returns the -EEXISTS to the caller anyway. Because the watch is still active in xenstored it will cause an event which will arrive in the new kernel. process_msg() will find the encapsulated struct xenbus_watch in its list of registered watches and puts the "empty" watch handle in the queue for xenwatch_thread(). xenwatch_thread() then calls ->callback which was cleared earlier by xenbus_watch_path(). To prevent that crash in a guest running on an old xen toolstack remove the special -EEXIST handling. v2: - remove the EEXIST handing in register_xenbus_watch() instead of checking for ->callback in process_msg() Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Olaf Hering <olaf@aepfle.de> |
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| .. | ||
| Makefile | ||
| xenbus_client.c | ||
| xenbus_comms.c | ||
| xenbus_comms.h | ||
| xenbus_probe_backend.c | ||
| xenbus_probe_frontend.c | ||
| xenbus_probe.c | ||
| xenbus_probe.h | ||
| xenbus_xs.c | ||