On Tue, 2 Apr 2019 17:11:29 +0100 Daniel P. Berrangé <[email protected]> wrote:
> On Tue, Apr 02, 2019 at 06:00:33PM +0200, Cornelia Huck wrote: > > On Fri, 29 Mar 2019 11:11:01 +0000 > > Daniel P. Berrangé <[email protected]> wrote: > > > > > The GCC 9 compiler complains about many places in s390 code > > > that take the address of members of the 'struct SCHIB' which > > > is marked packed: > > > > > > hw/vfio/ccw.c: In function ‘vfio_ccw_io_notifier_handler’: > > > hw/vfio/ccw.c:133:15: warning: taking address of packed member of ‘struct > > > SCHIB’ may result in an unaligned pointer value \ > > > [-Waddress-of-packed-member] > > > 133 | SCSW *s = &sch->curr_status.scsw; > > > | ^~~~~~~~~~~~~~~~~~~~~~ > > > hw/vfio/ccw.c:134:15: warning: taking address of packed member of ‘struct > > > SCHIB’ may result in an unaligned pointer value \ > > > [-Waddress-of-packed-member] > > > 134 | PMCW *p = &sch->curr_status.pmcw; > > > | ^~~~~~~~~~~~~~~~~~~~~~ > > > > > > ...snip many more... > > > > > > Almost all of these are just done for convenience to avoid > > > typing out long variable/field names when referencing struct > > > members. We can get most of this convenience by taking the > > > address of the 'struct SCHIB' instead, avoiding triggering > > > the compiler warnings. > > > > > > In a couple of places we copy via a local variable which is > > > a technique already applied elsewhere in s390 code for this > > > problem. > > > > > > Signed-off-by: Daniel P. Berrangé <[email protected]> > > > --- > > > hw/vfio/ccw.c | 42 ++++++++++++++++++++++-------------------- > > > 1 file changed, 22 insertions(+), 20 deletions(-) > > > > I'm currently in the process of queuing this and the other three s390x > > fixes, but I'm inclined to do so for 4.1 (it feels a bit late in the > > cycle for 4.0.) > > > > Other opinions? > > It would be nice to be warning free for 4.0, but I agree that it feels > kind of late to be making these changes. They're not fixing real world > bugs, and even if you queue the s390 bits we're unlikely to get all the > others merged, especially the usb-mtp one is a nasty mess. So we'll > not be 100% warning free. Yeah, but OTOH, the s390x changes are straightforward and have been reviewed by several people. So I changed my mind and queued them to s390-fixes :)
