diff options
| author |   mpi <mpi@openbsd.org> | 2018-09-25 13:46:44 +0000 |
|---|---|---|
| committer | mpi <mpi@openbsd.org> | 2018-09-25 13:46:44 +0000 |
| commit | 126b881f7106e87cadecac4b4ad6f06b70f71973 (patch) | |
| tree | 7032cb17f59b24215e4c766db0de131c1ac7ab7e | |
| parent | disklabel(8) uses hw.physmem to calculate swap and /var sizes. This (diff) | |
| download | wireguard-openbsd-126b881f7106e87cadecac4b4ad6f06b70f71973.tar.xz wireguard-openbsd-126b881f7106e87cadecac4b4ad6f06b70f71973.zip | |
Insert a workaround for per-ifp ioctl being called w/o NET_LOCK().
An example of such code path is vlan_destroy() where we don't want to
grab the lock because this driver is already NET_LOCK()-free.
The real solution to this problem is to stop holding the NET_LOCK() around
driver *_ioctl() routines.
Problem reported & fix tested by Élie Bouttier, ok visa@, bluhm@
| -rw-r--r-- | sys/dev/pv/if_vio.c | 23 |
1 files changed, 18 insertions, 5 deletions
diff --git a/sys/dev/pv/if_vio.c b/sys/dev/pv/if_vio.c index 432daf9a32e..46471f04181 100644 --- a/sys/dev/pv/if_vio.c +++ b/sys/dev/pv/if_vio.c @@ -1,4 +1,4 @@ -/* $OpenBSD: if_vio.c,v 1.5 2018/02/27 08:44:58 mpi Exp $ */ +/* $OpenBSD: if_vio.c,v 1.6 2018/09/25 13:46:44 mpi Exp $ */ /* * Copyright (c) 2012 Stefan Fritsch, Alexander Fiveg. @@ -1270,14 +1270,28 @@ out: return r; } +/* + * XXXSMP As long as some per-ifp ioctl(2)s are executed with the + * NET_LOCK() deadlocks are possible. So release it here. + */ +static inline int +vio_sleep(struct vio_softc *sc, const char *wmesg) +{ + int status = rw_status(&netlock); + + if (status != RW_WRITE && status != RW_READ) + return tsleep(&sc->sc_ctrl_inuse, PRIBIO|PCATCH, wmesg, 0); + + return rwsleep(&sc->sc_ctrl_inuse, &netlock, PRIBIO|PCATCH, wmesg, 0); +} + int vio_wait_ctrl(struct vio_softc *sc) { int r = 0; while (sc->sc_ctrl_inuse != FREE) { - r = rwsleep(&sc->sc_ctrl_inuse, &netlock, PRIBIO|PCATCH, - "viowait", 0); + r = vio_sleep(sc, "viowait"); if (r == EINTR) return r; } @@ -1296,8 +1310,7 @@ vio_wait_ctrl_done(struct vio_softc *sc) r = 1; break; } - r = rwsleep(&sc->sc_ctrl_inuse, &netlock, PRIBIO|PCATCH, - "viodone", 0); + r = vio_sleep(sc, "viodone"); if (r == EINTR) break; } |