| Message ID | 20201107150851.87008-1-ani@anisinha.ca (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [PATCH-for-5.2] acpi-build: Fix maybe-uninitialized warning when ACPI hotplug is off | expand |
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 <philmd@redhat.com> > Signed-off-by: Ani Sinha <ani@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. > -- > 2.25.1
On Sat, Nov 7, 2020 at 9:56 PM Michael S. Tsirkin <mst@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 <philmd@redhat.com> > > Signed-off-by: Ani Sinha <ani@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 >
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);
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 <philmd@redhat.com> Signed-off-by: Ani Sinha <ani@anisinha.ca> --- hw/i386/acpi-build.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)