| Message ID | 20190702180928.18113-1-farman@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | vfio-ccw: Fix the conversion of Format-0 CCWs to Format-1 | expand |
On Tue, 2 Jul 2019 20:09:28 +0200 Eric Farman <farman@linux.ibm.com> wrote: > When processing Format-0 CCWs, we use the "len" variable as the > number of CCWs to convert to Format-1. But that variable > contains zero here, and is not a meaningful CCW count until > ccwchain_calc_length() returns. Since that routine requires and > expects Format-1 CCWs to identify the chaining behavior, the > format conversion must be done first. The usage of the 'len' variable in the function is a bit confusing anyway. > > Convert the 2KB we copied even if it's more than we need. > > Fixes: 7f8e89a8f2fd ("vfio-ccw: Factor out the ccw0-to-ccw1 transition") > Reported-by: Farhan Ali <alifm@linux.ibm.com> > Signed-off-by: Eric Farman <farman@linux.ibm.com> > --- > drivers/s390/cio/vfio_ccw_cp.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c > index 9cddc1288059..a870bde10445 100644 > --- a/drivers/s390/cio/vfio_ccw_cp.c > +++ b/drivers/s390/cio/vfio_ccw_cp.c > @@ -431,7 +431,7 @@ static int ccwchain_handle_ccw(u32 cda, struct channel_program *cp) > > /* Convert any Format-0 CCWs to Format-1 */ > if (!cp->orb.cmd.fmt) > - convert_ccw0_to_ccw1(cp->guest_cp, len); > + convert_ccw0_to_ccw1(cp->guest_cp, CCWCHAIN_LEN_MAX); > > /* Count the CCWs in the current chain */ > len = ccwchain_calc_length(cda, cp); Reviewed-by: Cornelia Huck <cohuck@redhat.com>
On Wed, 3 Jul 2019 11:07:04 +0200 Cornelia Huck <cohuck@redhat.com> wrote: > On Tue, 2 Jul 2019 20:09:28 +0200 > Eric Farman <farman@linux.ibm.com> wrote: > > > When processing Format-0 CCWs, we use the "len" variable as the > > number of CCWs to convert to Format-1. But that variable > > contains zero here, and is not a meaningful CCW count until > > ccwchain_calc_length() returns. Since that routine requires and > > expects Format-1 CCWs to identify the chaining behavior, the > > format conversion must be done first. > > The usage of the 'len' variable in the function is a bit confusing > anyway. > > > > > Convert the 2KB we copied even if it's more than we need. > > > > Fixes: 7f8e89a8f2fd ("vfio-ccw: Factor out the ccw0-to-ccw1 transition") > > Reported-by: Farhan Ali <alifm@linux.ibm.com> > > Signed-off-by: Eric Farman <farman@linux.ibm.com> > > --- > > drivers/s390/cio/vfio_ccw_cp.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c > > index 9cddc1288059..a870bde10445 100644 > > --- a/drivers/s390/cio/vfio_ccw_cp.c > > +++ b/drivers/s390/cio/vfio_ccw_cp.c > > @@ -431,7 +431,7 @@ static int ccwchain_handle_ccw(u32 cda, struct channel_program *cp) > > > > /* Convert any Format-0 CCWs to Format-1 */ > > if (!cp->orb.cmd.fmt) > > - convert_ccw0_to_ccw1(cp->guest_cp, len); > > + convert_ccw0_to_ccw1(cp->guest_cp, CCWCHAIN_LEN_MAX); > > > > /* Count the CCWs in the current chain */ > > len = ccwchain_calc_length(cda, cp); > > Reviewed-by: Cornelia Huck <cohuck@redhat.com> And queued. I'll send a pull req for this now; we can always do a second round for the other patches.
diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c index 9cddc1288059..a870bde10445 100644 --- a/drivers/s390/cio/vfio_ccw_cp.c +++ b/drivers/s390/cio/vfio_ccw_cp.c @@ -431,7 +431,7 @@ static int ccwchain_handle_ccw(u32 cda, struct channel_program *cp) /* Convert any Format-0 CCWs to Format-1 */ if (!cp->orb.cmd.fmt) - convert_ccw0_to_ccw1(cp->guest_cp, len); + convert_ccw0_to_ccw1(cp->guest_cp, CCWCHAIN_LEN_MAX); /* Count the CCWs in the current chain */ len = ccwchain_calc_length(cda, cp);
When processing Format-0 CCWs, we use the "len" variable as the number of CCWs to convert to Format-1. But that variable contains zero here, and is not a meaningful CCW count until ccwchain_calc_length() returns. Since that routine requires and expects Format-1 CCWs to identify the chaining behavior, the format conversion must be done first. Convert the 2KB we copied even if it's more than we need. Fixes: 7f8e89a8f2fd ("vfio-ccw: Factor out the ccw0-to-ccw1 transition") Reported-by: Farhan Ali <alifm@linux.ibm.com> Signed-off-by: Eric Farman <farman@linux.ibm.com> --- drivers/s390/cio/vfio_ccw_cp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)