diff options
| author | Cornelia Huck <cohuck@redhat.com> | 2019-03-11 10:59:53 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-04-03 06:25:21 +0200 |
| commit | 2cca5be88ac06622da6c6aaa8a2dc7d0ed28c25e (patch) | |
| tree | 14aa5fcbc1f7b2c7290e77a179fd9fb079b1ebf7 /drivers/s390 | |
| parent | 1cb3e7f166b5c3efea42d2576eb2d4625a6c81ac (diff) | |
vfio: ccw: only free cp on final interrupt
commit 50b7f1b7236bab08ebbbecf90521e84b068d7a17 upstream.
When we get an interrupt for a channel program, it is not
necessarily the final interrupt; for example, the issuing
guest may request an intermediate interrupt by specifying
the program-controlled-interrupt flag on a ccw.
We must not switch the state to idle if the interrupt is not
yet final; even more importantly, we must not free the translated
channel program if the interrupt is not yet final, or the host
can crash during cp rewind.
Fixes: e5f84dbaea59 ("vfio: ccw: return I/O results asynchronously")
Cc: stable@vger.kernel.org # v4.12+
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/s390')
| -rw-r--r-- | drivers/s390/cio/vfio_ccw_drv.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c index ae7a49ade414..d22759eb6640 100644 --- a/drivers/s390/cio/vfio_ccw_drv.c +++ b/drivers/s390/cio/vfio_ccw_drv.c @@ -70,20 +70,24 @@ static void vfio_ccw_sch_io_todo(struct work_struct *work) { struct vfio_ccw_private *private; struct irb *irb; + bool is_final; private = container_of(work, struct vfio_ccw_private, io_work); irb = &private->irb; + is_final = !(scsw_actl(&irb->scsw) & + (SCSW_ACTL_DEVACT | SCSW_ACTL_SCHACT)); if (scsw_is_solicited(&irb->scsw)) { cp_update_scsw(&private->cp, &irb->scsw); - cp_free(&private->cp); + if (is_final) + cp_free(&private->cp); } memcpy(private->io_region.irb_area, irb, sizeof(*irb)); if (private->io_trigger) eventfd_signal(private->io_trigger, 1); - if (private->mdev) + if (private->mdev && is_final) private->state = VFIO_CCW_STATE_IDLE; } |