Re: [PATCH] accel/kvm: ensure ret always set

[Philippe Mathieu-Daudé]

On 10/3/19 11:22 AM, Stefano Garzarella wrote:
> On Wed, Oct 02, 2019 at 01:08:40PM +0200, Paolo Bonzini wrote:
> > On 02/10/19 12:22, Alex Bennée wrote:
> > > Some of the cross compilers rightly complain there are cases where ret
> > > may not be set. 0 seems to be the reasonable default unless particular
> > > slot explicitly returns -1.
>
> Even Coverity reported it (CID 1405857).

And GCC ;)

/home/phil/source/qemu/accel/kvm/kvm-all.c: In function ‘kvm_log_clear’:
/home/phil/source/qemu/accel/kvm/kvm-all.c:1121:8: error: ‘ret’ may be 
used uninitialized in this function [-Werror=maybe-uninitialized]
     if (r < 0) {
        ^
cc1: all warnings being treated as errors
make[1]: *** [/home/phil/source/qemu/rules.mak:69: accel/kvm/kvm-all.o] 
Error 1

Fixes: 4222147dfb7

> > > Signed-off-by: Alex Bennée <address@hidden>
> > > ---
> > >   accel/kvm/kvm-all.c | 6 +++---
> > >   1 file changed, 3 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
> > > index aabe097c41..d2d96d73e8 100644
> > > --- a/accel/kvm/kvm-all.c
> > > +++ b/accel/kvm/kvm-all.c
> > > @@ -712,11 +712,11 @@ static int kvm_physical_log_clear(KVMMemoryListener *kml,
> > >       KVMState *s = kvm_state;
> > >       uint64_t start, size, offset, count;
> > >       KVMSlot *mem;
> > > -    int ret, i;
> > > +    int ret = 0, i;
> > >   
> > >       if (!s->manual_dirty_log_protect) {
> > >           /* No need to do explicit clear */
> > > -        return 0;
> > > +        return ret;
> > >       }
> > >   
> > >       start = section->offset_within_address_space;
> > > @@ -724,7 +724,7 @@ static int kvm_physical_log_clear(KVMMemoryListener *kml,
> > >   
> > >       if (!size) {
> > >           /* Nothing more we can do... */
> > > -        return 0;
> > > +        return ret;
> > >       }
> > >   
> > >       kvm_slots_lock(kml);
> >
> > Queued, thanks.
> >
> > Paolo