Author: royger Date: Tue Mar 7 09:17:48 2017 New Revision: 314841 URL: https://svnweb.freebsd.org/changeset/base/314841
Log: xenstore: fix suspension when using the xenstore device Lock the xenstore request mutex when suspending user-space processes, in order to prevent any process from holding this lock when going into suspension, or else the xenstore suspend process is going to deadlock. Submitted by: Liuyingdong <[email protected]> Reviewed by: royger MFC after: 2 weeks Differential revision: https://reviews.freebsd.org/D9638 Modified: head/sys/dev/xen/control/control.c head/sys/dev/xen/xenstore/xenstore.c head/sys/xen/xenstore/xenstorevar.h Modified: head/sys/dev/xen/control/control.c ============================================================================== --- head/sys/dev/xen/control/control.c Tue Mar 7 09:16:51 2017 (r314840) +++ head/sys/dev/xen/control/control.c Tue Mar 7 09:17:48 2017 (r314841) @@ -199,7 +199,9 @@ xctrl_suspend() #endif EVENTHANDLER_INVOKE(power_suspend_early); + xs_lock(); stop_all_proc(); + xs_unlock(); EVENTHANDLER_INVOKE(power_suspend); #ifdef EARLY_AP_STARTUP Modified: head/sys/dev/xen/xenstore/xenstore.c ============================================================================== --- head/sys/dev/xen/xenstore/xenstore.c Tue Mar 7 09:16:51 2017 (r314840) +++ head/sys/dev/xen/xenstore/xenstore.c Tue Mar 7 09:17:48 2017 (r314841) @@ -1699,3 +1699,20 @@ xs_unregister_watch(struct xs_watch *wat sx_xunlock(&xs.xenwatch_mutex); } } + +void +xs_lock(void) +{ + + sx_xlock(&xs.request_mutex); + return; +} + +void +xs_unlock(void) +{ + + sx_xunlock(&xs.request_mutex); + return; +} + Modified: head/sys/xen/xenstore/xenstorevar.h ============================================================================== --- head/sys/xen/xenstore/xenstorevar.h Tue Mar 7 09:16:51 2017 (r314840) +++ head/sys/xen/xenstore/xenstorevar.h Tue Mar 7 09:17:48 2017 (r314841) @@ -338,4 +338,15 @@ void xs_unregister_watch(struct xs_watch */ struct sbuf *xs_join(const char *, const char *); +/** + * Lock the xenstore request mutex. + */ +void xs_lock(void); + +/** + * Unlock the xenstore request mutex. + */ +void xs_unlock(void); + #endif /* _XEN_XENSTORE_XENSTOREVAR_H */ + _______________________________________________ [email protected] mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "[email protected]"
