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MFC r256362

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Fix a lock-order reversal in the net driver by dropping the lock
  and holding a reference prior to calling further into the hyperv
  stack.

  Added missing FreeBSD idents.

Approved by:	re@ (gjb)
This commit is contained in:
grehan 2013-10-12 00:42:41 +00:00
parent c8e8fef3a6
commit 89a272e3b9
2 changed files with 86 additions and 19 deletions
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4
sys/dev/hyperv/netvsc/hv_net_vsc.h
View File

@ -24,6 +24,8 @@
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $FreeBSD$
*/
/*
@ -970,6 +972,8 @@ typedef struct hn_softc {
int hn_if_flags;
struct mtx hn_lock;
int hn_initdone;
/* See hv_netvsc_drv_freebsd.c for rules on how to use */
int temp_unusable;
struct hv_device *hn_dev_obj;
netvsc_dev *net_dev;
} hn_softc_t;

101
sys/dev/hyperv/netvsc/hv_netvsc_drv_freebsd.c
View File

@ -52,6 +52,9 @@
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sockio.h>
@ -701,6 +704,17 @@ netvsc_recv(struct hv_device *device_ctx, netvsc_packet *packet)
return (0);
}
/*
* Rules for using sc->temp_unusable:
* 1. sc->temp_unusable can only be read or written while holding NV_LOCK()
* 2. code reading sc->temp_unusable under NV_LOCK(), and finding
* sc->temp_unusable set, must release NV_LOCK() and exit
* 3. to retain exclusive control of the interface,
* sc->temp_unusable must be set by code before releasing NV_LOCK()
* 4. only code setting sc->temp_unusable can clear sc->temp_unusable
* 5. code setting sc->temp_unusable must eventually clear sc->temp_unusable
*/
/*
* Standard ioctl entry point. Called when the user wants to configure
* the interface.
@ -713,7 +727,8 @@ hn_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
netvsc_device_info device_info;
struct hv_device *hn_dev;
int mask, error = 0;
int retry_cnt = 500;
switch(cmd) {
case SIOCSIFADDR:
@ -723,38 +738,80 @@ hn_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
case SIOCSIFMTU:
hn_dev = vmbus_get_devctx(sc->hn_dev);
NV_LOCK(sc);
/* Check MTU value change */
if (ifp->if_mtu == ifr->ifr_mtu)
break;
if (ifr->ifr_mtu > NETVSC_MAX_CONFIGURABLE_MTU) {
error = EINVAL;
NV_UNLOCK(sc);
break;
}
/* Obtain and record requested MTU */
ifp->if_mtu = ifr->ifr_mtu;
do {
NV_LOCK(sc);
if (!sc->temp_unusable) {
sc->temp_unusable = TRUE;
retry_cnt = -1;
}
NV_UNLOCK(sc);
if (retry_cnt > 0) {
retry_cnt--;
DELAY(5 * 1000);
}
} while (retry_cnt > 0);
/*
* We must remove and add back the device to cause the new
if (retry_cnt == 0) {
error = EINVAL;
break;
}
/* We must remove and add back the device to cause the new
* MTU to take effect. This includes tearing down, but not
* deleting the channel, then bringing it back up.
*/
error = hv_rf_on_device_remove(hn_dev, HV_RF_NV_RETAIN_CHANNEL);
if (error) {
NV_LOCK(sc);
sc->temp_unusable = FALSE;
NV_UNLOCK(sc);
break;
}
error = hv_rf_on_device_add(hn_dev, &device_info);
if (error) {
NV_LOCK(sc);
sc->temp_unusable = FALSE;
NV_UNLOCK(sc);
break;
}
hn_ifinit_locked(sc);
NV_LOCK(sc);
sc->temp_unusable = FALSE;
NV_UNLOCK(sc);
break;
case SIOCSIFFLAGS:
NV_LOCK(sc);
do {
NV_LOCK(sc);
if (!sc->temp_unusable) {
sc->temp_unusable = TRUE;
retry_cnt = -1;
}
NV_UNLOCK(sc);
if (retry_cnt > 0) {
retry_cnt--;
DELAY(5 * 1000);
}
} while (retry_cnt > 0);
if (retry_cnt == 0) {
error = EINVAL;
break;
}
if (ifp->if_flags & IFF_UP) {
/*
* If only the state of the PROMISC flag changed,
@ -766,21 +823,14 @@ hn_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
*/
#ifdef notyet
/* Fixme: Promiscuous mode? */
/* No promiscuous mode with Xen */
if (ifp->if_drv_flags & IFF_DRV_RUNNING &&
ifp->if_flags & IFF_PROMISC &&
!(sc->hn_if_flags & IFF_PROMISC)) {
/* do something here for Hyper-V */
;
/* XN_SETBIT(sc, XN_RX_MODE, */
/* XN_RXMODE_RX_PROMISC); */
} else if (ifp->if_drv_flags & IFF_DRV_RUNNING &&
!(ifp->if_flags & IFF_PROMISC) &&
sc->hn_if_flags & IFF_PROMISC) {
!(ifp->if_flags & IFF_PROMISC) &&
sc->hn_if_flags & IFF_PROMISC) {
/* do something here for Hyper-V */
;
/* XN_CLRBIT(sc, XN_RX_MODE, */
/* XN_RXMODE_RX_PROMISC); */
} else
#endif
hn_ifinit_locked(sc);
@ -789,8 +839,10 @@ hn_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
hn_stop(sc);
}
}
sc->hn_if_flags = ifp->if_flags;
NV_LOCK(sc);
sc->temp_unusable = FALSE;
NV_UNLOCK(sc);
sc->hn_if_flags = ifp->if_flags;
error = 0;
break;
case SIOCSIFCAP:
@ -838,7 +890,6 @@ hn_stop(hn_softc_t *sc)
int ret;
struct hv_device *device_ctx = vmbus_get_devctx(sc->hn_dev);
NV_LOCK_ASSERT(sc);
ifp = sc->hn_ifp;
printf(" Closing Device ...\n");
@ -859,6 +910,10 @@ hn_start(struct ifnet *ifp)
sc = ifp->if_softc;
NV_LOCK(sc);
if (sc->temp_unusable) {
NV_UNLOCK(sc);
return;
}
hn_start_locked(ifp);
NV_UNLOCK(sc);
}
@ -873,8 +928,6 @@ hn_ifinit_locked(hn_softc_t *sc)
struct hv_device *device_ctx = vmbus_get_devctx(sc->hn_dev);
int ret;
NV_LOCK_ASSERT(sc);
ifp = sc->hn_ifp;
if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
@ -902,7 +955,17 @@ hn_ifinit(void *xsc)
hn_softc_t *sc = xsc;
NV_LOCK(sc);
if (sc->temp_unusable) {
NV_UNLOCK(sc);
return;
}
sc->temp_unusable = TRUE;
NV_UNLOCK(sc);
hn_ifinit_locked(sc);
NV_LOCK(sc);
sc->temp_unusable = FALSE;
NV_UNLOCK(sc);
}