* [PATCH] vdpa: fix gcc cvq_isolated uninitialized variable warning
@ 2023-09-11 21:54 Stefan Hajnoczi
2023-09-12 6:18 ` Philippe Mathieu-Daudé
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Stefan Hajnoczi @ 2023-09-11 21:54 UTC (permalink / raw)
To: qemu-devel
Cc: Jason Wang, Stefan Hajnoczi, Eugenio Pérez,
Michael S . Tsirkin
gcc 13.2.1 emits the following warning:
net/vhost-vdpa.c: In function ‘net_vhost_vdpa_init.constprop’:
net/vhost-vdpa.c:1394:25: error: ‘cvq_isolated’ may be used uninitialized [-Werror=maybe-uninitialized]
1394 | s->cvq_isolated = cvq_isolated;
| ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~
net/vhost-vdpa.c:1355:9: note: ‘cvq_isolated’ was declared here
1355 | int cvq_isolated;
| ^~~~~~~~~~~~
cc1: all warnings being treated as errors
Cc: Eugenio Pérez <eperezma@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
net/vhost-vdpa.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
index 34202ca009..7eaee841aa 100644
--- a/net/vhost-vdpa.c
+++ b/net/vhost-vdpa.c
@@ -1352,7 +1352,7 @@ static NetClientState *net_vhost_vdpa_init(NetClientState *peer,
VhostVDPAState *s;
int ret = 0;
assert(name);
- int cvq_isolated;
+ int cvq_isolated = 0;
if (is_datapath) {
nc = qemu_new_net_client(&net_vhost_vdpa_info, peer, device,
--
2.41.0
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH] vdpa: fix gcc cvq_isolated uninitialized variable warning 2023-09-11 21:54 [PATCH] vdpa: fix gcc cvq_isolated uninitialized variable warning Stefan Hajnoczi @ 2023-09-12 6:18 ` Philippe Mathieu-Daudé 2023-09-12 10:48 ` Stefan Hajnoczi 2023-09-12 6:46 ` Eugenio Perez Martin 2023-09-15 5:30 ` Jason Wang 2 siblings, 1 reply; 6+ messages in thread From: Philippe Mathieu-Daudé @ 2023-09-12 6:18 UTC (permalink / raw) To: Stefan Hajnoczi, qemu-devel Cc: Jason Wang, Eugenio Pérez, Michael S . Tsirkin On 11/9/23 23:54, Stefan Hajnoczi wrote: > gcc 13.2.1 emits the following warning: > > net/vhost-vdpa.c: In function ‘net_vhost_vdpa_init.constprop’: > net/vhost-vdpa.c:1394:25: error: ‘cvq_isolated’ may be used uninitialized [-Werror=maybe-uninitialized] > 1394 | s->cvq_isolated = cvq_isolated; > | ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~ > net/vhost-vdpa.c:1355:9: note: ‘cvq_isolated’ was declared here > 1355 | int cvq_isolated; > | ^~~~~~~~~~~~ > cc1: all warnings being treated as errors > > Cc: Eugenio Pérez <eperezma@redhat.com> > Cc: Michael S. Tsirkin <mst@redhat.com> > Cc: Jason Wang <jasowang@redhat.com> > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> > --- > net/vhost-vdpa.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c > index 34202ca009..7eaee841aa 100644 > --- a/net/vhost-vdpa.c > +++ b/net/vhost-vdpa.c > @@ -1352,7 +1352,7 @@ static NetClientState *net_vhost_vdpa_init(NetClientState *peer, > VhostVDPAState *s; > int ret = 0; > assert(name); > - int cvq_isolated; > + int cvq_isolated = 0; > > if (is_datapath) { > nc = qemu_new_net_client(&net_vhost_vdpa_info, peer, device, Alternatively: -- >8 -- diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c index 34202ca009..218fe0c305 100644 --- a/net/vhost-vdpa.c +++ b/net/vhost-vdpa.c @@ -1352,13 +1352,12 @@ static NetClientState *net_vhost_vdpa_init(NetClientState *peer, VhostVDPAState *s; int ret = 0; assert(name); - int cvq_isolated; if (is_datapath) { nc = qemu_new_net_client(&net_vhost_vdpa_info, peer, device, name); } else { - cvq_isolated = vhost_vdpa_probe_cvq_isolation(vdpa_device_fd, features, + int cvq_isolated = vhost_vdpa_probe_cvq_isolation(vdpa_device_fd, features, queue_pair_index * 2, errp); if (unlikely(cvq_isolated < 0)) { @@ -1391,7 +1390,7 @@ static NetClientState *net_vhost_vdpa_init(NetClientState *peer, s->vhost_vdpa.shadow_vq_ops = &vhost_vdpa_net_svq_ops; s->vhost_vdpa.shadow_vq_ops_opaque = s; - s->cvq_isolated = cvq_isolated; + s->cvq_isolated = true; --- Whichever you prefer: Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> ^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] vdpa: fix gcc cvq_isolated uninitialized variable warning 2023-09-12 6:18 ` Philippe Mathieu-Daudé @ 2023-09-12 10:48 ` Stefan Hajnoczi 2023-09-12 11:17 ` Philippe Mathieu-Daudé 0 siblings, 1 reply; 6+ messages in thread From: Stefan Hajnoczi @ 2023-09-12 10:48 UTC (permalink / raw) To: Philippe Mathieu-Daudé Cc: Stefan Hajnoczi, qemu-devel, Jason Wang, Eugenio Pérez, Michael S . Tsirkin On Tue, 12 Sept 2023 at 02:19, Philippe Mathieu-Daudé <philmd@linaro.org> wrote: > > On 11/9/23 23:54, Stefan Hajnoczi wrote: > > gcc 13.2.1 emits the following warning: > > > > net/vhost-vdpa.c: In function ‘net_vhost_vdpa_init.constprop’: > > net/vhost-vdpa.c:1394:25: error: ‘cvq_isolated’ may be used uninitialized [-Werror=maybe-uninitialized] > > 1394 | s->cvq_isolated = cvq_isolated; > > | ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~ > > net/vhost-vdpa.c:1355:9: note: ‘cvq_isolated’ was declared here > > 1355 | int cvq_isolated; > > | ^~~~~~~~~~~~ > > cc1: all warnings being treated as errors > > > > Cc: Eugenio Pérez <eperezma@redhat.com> > > Cc: Michael S. Tsirkin <mst@redhat.com> > > Cc: Jason Wang <jasowang@redhat.com> > > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> > > --- > > net/vhost-vdpa.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c > > index 34202ca009..7eaee841aa 100644 > > --- a/net/vhost-vdpa.c > > +++ b/net/vhost-vdpa.c > > @@ -1352,7 +1352,7 @@ static NetClientState *net_vhost_vdpa_init(NetClientState *peer, > > VhostVDPAState *s; > > int ret = 0; > > assert(name); > > - int cvq_isolated; > > + int cvq_isolated = 0; > > > > if (is_datapath) { > > nc = qemu_new_net_client(&net_vhost_vdpa_info, peer, device, > > Alternatively: > > -- >8 -- > diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c > index 34202ca009..218fe0c305 100644 > --- a/net/vhost-vdpa.c > +++ b/net/vhost-vdpa.c > @@ -1352,13 +1352,12 @@ static NetClientState > *net_vhost_vdpa_init(NetClientState *peer, > VhostVDPAState *s; > int ret = 0; > assert(name); > - int cvq_isolated; > > if (is_datapath) { > nc = qemu_new_net_client(&net_vhost_vdpa_info, peer, device, > name); > } else { > - cvq_isolated = vhost_vdpa_probe_cvq_isolation(vdpa_device_fd, > features, > + int cvq_isolated = > vhost_vdpa_probe_cvq_isolation(vdpa_device_fd, features, > queue_pair_index > * 2, > errp); > if (unlikely(cvq_isolated < 0)) { > @@ -1391,7 +1390,7 @@ static NetClientState > *net_vhost_vdpa_init(NetClientState *peer, > > s->vhost_vdpa.shadow_vq_ops = &vhost_vdpa_net_svq_ops; > s->vhost_vdpa.shadow_vq_ops_opaque = s; > - s->cvq_isolated = cvq_isolated; > + s->cvq_isolated = true; This is incorrect because the return value of vhost_vdpa_probe_cvq_isolation() is -errno for errors, 0 for no cvq isolation, and 1 for cvq isolation. A variable is still needed to distinguish between no cvq isolation and cvq isolation. > > --- > > Whichever you prefer: > > Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> > > ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] vdpa: fix gcc cvq_isolated uninitialized variable warning 2023-09-12 10:48 ` Stefan Hajnoczi @ 2023-09-12 11:17 ` Philippe Mathieu-Daudé 0 siblings, 0 replies; 6+ messages in thread From: Philippe Mathieu-Daudé @ 2023-09-12 11:17 UTC (permalink / raw) To: Stefan Hajnoczi Cc: Stefan Hajnoczi, qemu-devel, Jason Wang, Eugenio Pérez, Michael S . Tsirkin On 12/9/23 12:48, Stefan Hajnoczi wrote: > On Tue, 12 Sept 2023 at 02:19, Philippe Mathieu-Daudé <philmd@linaro.org> wrote: >> >> On 11/9/23 23:54, Stefan Hajnoczi wrote: >>> gcc 13.2.1 emits the following warning: >>> >>> net/vhost-vdpa.c: In function ‘net_vhost_vdpa_init.constprop’: >>> net/vhost-vdpa.c:1394:25: error: ‘cvq_isolated’ may be used uninitialized [-Werror=maybe-uninitialized] >>> 1394 | s->cvq_isolated = cvq_isolated; >>> | ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~ >>> net/vhost-vdpa.c:1355:9: note: ‘cvq_isolated’ was declared here >>> 1355 | int cvq_isolated; >>> | ^~~~~~~~~~~~ >>> cc1: all warnings being treated as errors >>> >>> Cc: Eugenio Pérez <eperezma@redhat.com> >>> Cc: Michael S. Tsirkin <mst@redhat.com> >>> Cc: Jason Wang <jasowang@redhat.com> >>> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> >>> --- >>> net/vhost-vdpa.c | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c >>> index 34202ca009..7eaee841aa 100644 >>> --- a/net/vhost-vdpa.c >>> +++ b/net/vhost-vdpa.c >>> @@ -1352,7 +1352,7 @@ static NetClientState *net_vhost_vdpa_init(NetClientState *peer, >>> VhostVDPAState *s; >>> int ret = 0; >>> assert(name); >>> - int cvq_isolated; >>> + int cvq_isolated = 0; >>> >>> if (is_datapath) { >>> nc = qemu_new_net_client(&net_vhost_vdpa_info, peer, device, >> >> Alternatively: >> >> -- >8 -- >> diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c >> index 34202ca009..218fe0c305 100644 >> --- a/net/vhost-vdpa.c >> +++ b/net/vhost-vdpa.c >> @@ -1352,13 +1352,12 @@ static NetClientState >> *net_vhost_vdpa_init(NetClientState *peer, >> VhostVDPAState *s; >> int ret = 0; >> assert(name); >> - int cvq_isolated; >> >> if (is_datapath) { >> nc = qemu_new_net_client(&net_vhost_vdpa_info, peer, device, >> name); >> } else { >> - cvq_isolated = vhost_vdpa_probe_cvq_isolation(vdpa_device_fd, >> features, >> + int cvq_isolated = >> vhost_vdpa_probe_cvq_isolation(vdpa_device_fd, features, >> queue_pair_index >> * 2, >> errp); >> if (unlikely(cvq_isolated < 0)) { >> @@ -1391,7 +1390,7 @@ static NetClientState >> *net_vhost_vdpa_init(NetClientState *peer, >> >> s->vhost_vdpa.shadow_vq_ops = &vhost_vdpa_net_svq_ops; >> s->vhost_vdpa.shadow_vq_ops_opaque = s; >> - s->cvq_isolated = cvq_isolated; >> + s->cvq_isolated = true; > > This is incorrect because the return value of > vhost_vdpa_probe_cvq_isolation() is -errno for errors, 0 for no cvq > isolation, and 1 for cvq isolation. A variable is still needed to > distinguish between no cvq isolation and cvq isolation. Oh, I was expecting a boolean for a field named 'cvq_isolated', my bad. R-b stands for your patch. Regards, Phil. > >> >> --- >> >> Whichever you prefer: >> >> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> >> >> ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] vdpa: fix gcc cvq_isolated uninitialized variable warning 2023-09-11 21:54 [PATCH] vdpa: fix gcc cvq_isolated uninitialized variable warning Stefan Hajnoczi 2023-09-12 6:18 ` Philippe Mathieu-Daudé @ 2023-09-12 6:46 ` Eugenio Perez Martin 2023-09-15 5:30 ` Jason Wang 2 siblings, 0 replies; 6+ messages in thread From: Eugenio Perez Martin @ 2023-09-12 6:46 UTC (permalink / raw) To: Stefan Hajnoczi; +Cc: qemu-devel, Jason Wang, Michael S . Tsirkin On Mon, Sep 11, 2023 at 11:54 PM Stefan Hajnoczi <stefanha@redhat.com> wrote: > > gcc 13.2.1 emits the following warning: > > net/vhost-vdpa.c: In function ‘net_vhost_vdpa_init.constprop’: > net/vhost-vdpa.c:1394:25: error: ‘cvq_isolated’ may be used uninitialized [-Werror=maybe-uninitialized] > 1394 | s->cvq_isolated = cvq_isolated; > | ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~ > net/vhost-vdpa.c:1355:9: note: ‘cvq_isolated’ was declared here > 1355 | int cvq_isolated; > | ^~~~~~~~~~~~ > cc1: all warnings being treated as errors > I think GCC is evaluating the case where (queue_pair_index == 0 && !is_datapath), which should be not possible. If it is useful we can refactor the conditionals so we don't need the variable at that level of the function. If not, Acked-by: Eugenio Pérez <eperezma@redhat.com> Thanks! > Cc: Eugenio Pérez <eperezma@redhat.com> > Cc: Michael S. Tsirkin <mst@redhat.com> > Cc: Jason Wang <jasowang@redhat.com> > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> > --- > net/vhost-vdpa.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c > index 34202ca009..7eaee841aa 100644 > --- a/net/vhost-vdpa.c > +++ b/net/vhost-vdpa.c > @@ -1352,7 +1352,7 @@ static NetClientState *net_vhost_vdpa_init(NetClientState *peer, > VhostVDPAState *s; > int ret = 0; > assert(name); > - int cvq_isolated; > + int cvq_isolated = 0; > > if (is_datapath) { > nc = qemu_new_net_client(&net_vhost_vdpa_info, peer, device, > -- > 2.41.0 > ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] vdpa: fix gcc cvq_isolated uninitialized variable warning 2023-09-11 21:54 [PATCH] vdpa: fix gcc cvq_isolated uninitialized variable warning Stefan Hajnoczi 2023-09-12 6:18 ` Philippe Mathieu-Daudé 2023-09-12 6:46 ` Eugenio Perez Martin @ 2023-09-15 5:30 ` Jason Wang 2 siblings, 0 replies; 6+ messages in thread From: Jason Wang @ 2023-09-15 5:30 UTC (permalink / raw) To: Stefan Hajnoczi; +Cc: qemu-devel, Eugenio Pérez, Michael S . Tsirkin On Tue, Sep 12, 2023 at 5:54 AM Stefan Hajnoczi <stefanha@redhat.com> wrote: > > gcc 13.2.1 emits the following warning: > > net/vhost-vdpa.c: In function ‘net_vhost_vdpa_init.constprop’: > net/vhost-vdpa.c:1394:25: error: ‘cvq_isolated’ may be used uninitialized [-Werror=maybe-uninitialized] > 1394 | s->cvq_isolated = cvq_isolated; > | ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~ > net/vhost-vdpa.c:1355:9: note: ‘cvq_isolated’ was declared here > 1355 | int cvq_isolated; > | ^~~~~~~~~~~~ > cc1: all warnings being treated as errors > > Cc: Eugenio Pérez <eperezma@redhat.com> > Cc: Michael S. Tsirkin <mst@redhat.com> > Cc: Jason Wang <jasowang@redhat.com> > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> Thanks > --- > net/vhost-vdpa.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c > index 34202ca009..7eaee841aa 100644 > --- a/net/vhost-vdpa.c > +++ b/net/vhost-vdpa.c > @@ -1352,7 +1352,7 @@ static NetClientState *net_vhost_vdpa_init(NetClientState *peer, > VhostVDPAState *s; > int ret = 0; > assert(name); > - int cvq_isolated; > + int cvq_isolated = 0; > > if (is_datapath) { > nc = qemu_new_net_client(&net_vhost_vdpa_info, peer, device, > -- > 2.41.0 > ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2023-09-15 5:31 UTC | newest] Thread overview: 6+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2023-09-11 21:54 [PATCH] vdpa: fix gcc cvq_isolated uninitialized variable warning Stefan Hajnoczi 2023-09-12 6:18 ` Philippe Mathieu-Daudé 2023-09-12 10:48 ` Stefan Hajnoczi 2023-09-12 11:17 ` Philippe Mathieu-Daudé 2023-09-12 6:46 ` Eugenio Perez Martin 2023-09-15 5:30 ` Jason Wang
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