Author: neel Date: Wed Apr 15 16:22:05 2015 New Revision: 281559 URL: https://svnweb.freebsd.org/changeset/base/281559
Log: Fix handling of BUS_PROBE_NOWILDCARD in 'device_probe_child()'. Device probe value of BUS_PROBE_NOWILDCARD should be treated specially only if the device has a fixed devclass. Otherwise it should be interpreted just as if the driver doesn't want to claim the device. Prior to this change a device that was not claimed explicitly by its driver would remain "attached" to the driver that returned BUS_PROBE_NOWILDCARD. This would bump up the reference on 'driver->refs' and its 'dev->ops' would point to the 'driver->ops'. When the driver is subsequently unloaded the 'dev->ops->cls' is left pointing to freed memory. This fixes an easily reproducible #GP fault caused by loading and unloading vmm.ko multiple times. Differential Revision: https://reviews.freebsd.org/D2294 Reviewed by: imp, jhb Discussed with: rstone Reported by: Leon Dang (ld...@nahannisys.com) MFC after: 2 weeks Modified: head/sys/kern/subr_bus.c Modified: head/sys/kern/subr_bus.c ============================================================================== --- head/sys/kern/subr_bus.c Wed Apr 15 14:46:45 2015 (r281558) +++ head/sys/kern/subr_bus.c Wed Apr 15 16:22:05 2015 (r281559) @@ -2113,6 +2113,16 @@ device_probe_child(device_t dev, device_ } /* + * Probes that return BUS_PROBE_NOWILDCARD or lower + * only match on devices whose driver was explicitly + * specified. + */ + if (result <= BUS_PROBE_NOWILDCARD && + !(child->flags & DF_FIXEDCLASS)) { + result = ENXIO; + } + + /* * The driver returned an error so it * certainly doesn't match. */ @@ -2127,14 +2137,6 @@ device_probe_child(device_t dev, device_ * of pri for the first match. */ if (best == NULL || result > pri) { - /* - * Probes that return BUS_PROBE_NOWILDCARD - * or lower only match on devices whose - * driver was explicitly specified. - */ - if (result <= BUS_PROBE_NOWILDCARD && - !(child->flags & DF_FIXEDCLASS)) - continue; best = dl; pri = result; continue; _______________________________________________ svn-src-head@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
