f3d54ded28
xenbus needs to keep track of the devices exposed on xenstore, so that it can trigger frontend and backend device creation. Removal of backend devices is currently detected by checking the existence of the device (backend) xenstore directory, but that's prone to races as the device driver would usually add entries to such directory itself, so under certain circumstances it's possible for a driver to add node to the directory after the toolstack has removed it. This leads to devices not removed, which can eventually exhaust the memory of FreeBSD. Fix this by checking for the existence of the 'state' node instead of the directory, as such node will always be present when a device is active, and will be removed by the toolstack when the device is shut down. In order to avoid any races with the updating of the 'state' node by FreeBSD and the toolstack removing it use a transaction in xenbusb_write_ivar() for that purpose. Reported by: Ze Dupsys <zedupsys@gmail.com> Sponsored by: Citrix Systems R&D |
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| .. | ||
| xenbus_if.m | ||
| xenbus.c | ||
| xenbusb_back.c | ||
| xenbusb_front.c | ||
| xenbusb_if.m | ||
| xenbusb.c | ||
| xenbusb.h | ||
| xenbusvar.h | ||