On Sat, Nov 7, 2020 at 9:56 PM Michael S. Tsirkin <m...@redhat.com> wrote:
>
> On Sat, Nov 07, 2020 at 08:38:51PM +0530, Ani Sinha wrote:
> > This fixes the following warning (gcc 9.3.0 on Ubuntu):
> >
> > ../hw/i386/acpi-build.c: In function 'build_append_pci_bus_devices':
> > ../hw/i386/acpi-build.c:496:9: error: 'method' may be used uninitialized
> > in this function [-Werror=maybe-uninitialized]
> > 496 | aml_append(parent_scope, method);
> > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > cc1: all warnings being treated as errors
> >
> > Fixes: df4008c9c59 ("piix4: don't reserve hw resources when hotplug is off
> > globally")
> > Reported-by: Philippe Mathieu-Daudé <phi...@redhat.com>
> > Signed-off-by: Ani Sinha <a...@anisinha.ca>
> > ---
> > hw/i386/acpi-build.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> > index 4f66642d88..79b86d4a36 100644
> > --- a/hw/i386/acpi-build.c
> > +++ b/hw/i386/acpi-build.c
> > @@ -349,7 +349,7 @@ static void build_append_pcihp_notify_entry(Aml
> > *method, int slot)
> > static void build_append_pci_bus_devices(Aml *parent_scope, PCIBus *bus,
> > bool pcihp_bridge_en)
> > {
> > - Aml *dev, *notify_method = NULL, *method;
> > + Aml *dev, *notify_method = NULL, *method = NULL;
> > QObject *bsel;
> > PCIBus *sec;
> > int i;
> > @@ -492,7 +492,7 @@ static void build_append_pci_bus_devices(Aml
> > *parent_scope, PCIBus *bus,
> > }
> > }
> >
> > - if (bsel || pcihp_bridge_en) {
> > + if (method) {
> > aml_append(parent_scope, method);
> > }
> > qobject_unref(bsel);
>
> I prefer Philippe's fix I think - gcc does not warn about it but
> using method when it's NULL would lead to a crash.
I could be wrong but I do not see a case where we are using a method
which is uninitialized first.
I did see another bug in my V1 and I fixed it in V2.
>
> > --
> > 2.25.1
>
