hw/i386/acpi-build.c | 45 +++++++++++++++++++++----------------------- 1 file changed, 21 insertions(+), 24 deletions(-)
'method' can be left uninitialized. Restrict some code to be used
only in the "if (bsel || pcihp_bridge_en)" block statement.
This fixes (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")
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
RFC because I have no clue about this code
---
hw/i386/acpi-build.c | 45 +++++++++++++++++++++-----------------------
1 file changed, 21 insertions(+), 24 deletions(-)
diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index 4f66642d887..1f5c2112452 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -465,34 +465,31 @@ static void build_append_pci_bus_devices(Aml *parent_scope, PCIBus *bus,
*/
if (bsel || pcihp_bridge_en) {
method = aml_method("PCNT", 0, AML_NOTSERIALIZED);
- }
- /* If bus supports hotplug select it and notify about local events */
- if (bsel) {
- uint64_t bsel_val = qnum_get_uint(qobject_to(QNum, bsel));
- aml_append(method, aml_store(aml_int(bsel_val), aml_name("BNUM")));
- aml_append(method,
- aml_call2("DVNT", aml_name("PCIU"), aml_int(1) /* Device Check */)
- );
- aml_append(method,
- aml_call2("DVNT", aml_name("PCID"), aml_int(3)/* Eject Request */)
- );
- }
+ /* If bus supports hotplug select it and notify about local events */
+ if (bsel) {
+ uint64_t bsel_val = qnum_get_uint(qobject_to(QNum, bsel));
- /* Notify about child bus events in any case */
- if (pcihp_bridge_en) {
- QLIST_FOREACH(sec, &bus->child, sibling) {
- int32_t devfn = sec->parent_dev->devfn;
-
- if (pci_bus_is_root(sec) || pci_bus_is_express(sec)) {
- continue;
- }
-
- aml_append(method, aml_name("^S%.02X.PCNT", devfn));
+ aml_append(method, aml_store(aml_int(bsel_val), aml_name("BNUM")));
+ aml_append(method, aml_call2("DVNT", aml_name("PCIU"),
+ aml_int(1))); /* Device Check */
+ aml_append(method, aml_call2("DVNT", aml_name("PCID"),
+ aml_int(3))); /* Eject Request */
+ }
+
+ /* Notify about child bus events in any case */
+ if (pcihp_bridge_en) {
+ QLIST_FOREACH(sec, &bus->child, sibling) {
+ int32_t devfn = sec->parent_dev->devfn;
+
+ if (pci_bus_is_root(sec) || pci_bus_is_express(sec)) {
+ continue;
+ }
+
+ aml_append(method, aml_name("^S%.02X.PCNT", devfn));
+ }
}
- }
- if (bsel || pcihp_bridge_en) {
aml_append(parent_scope, method);
}
qobject_unref(bsel);
--
2.26.2
On Sat, Nov 07, 2020 at 11:29:40AM +0100, Philippe Mathieu-Daudé wrote: > 'method' can be left uninitialized. Restrict some code to be used > only in the "if (bsel || pcihp_bridge_en)" block statement. > > This fixes (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 This code is already in the "if (bsel || pcihp_bridge_en)" block statement. the compiler just isn't smart enough to figure it out. I do like the change though, I think repeating the condition is fragile, it is better to have it in a single place. Pls repost with method can be left -> gcc 9 thinks that method can be left, no RFC tag, and I will apply. > Fixes: df4008c9c59 ("piix4: don't reserve hw resources when hotplug is off globally") > Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> > --- > RFC because I have no clue about this code > --- > hw/i386/acpi-build.c | 45 +++++++++++++++++++++----------------------- > 1 file changed, 21 insertions(+), 24 deletions(-) > > diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c > index 4f66642d887..1f5c2112452 100644 > --- a/hw/i386/acpi-build.c > +++ b/hw/i386/acpi-build.c > @@ -465,34 +465,31 @@ static void build_append_pci_bus_devices(Aml *parent_scope, PCIBus *bus, > */ > if (bsel || pcihp_bridge_en) { > method = aml_method("PCNT", 0, AML_NOTSERIALIZED); > - } > - /* If bus supports hotplug select it and notify about local events */ > - if (bsel) { > - uint64_t bsel_val = qnum_get_uint(qobject_to(QNum, bsel)); > > - aml_append(method, aml_store(aml_int(bsel_val), aml_name("BNUM"))); > - aml_append(method, > - aml_call2("DVNT", aml_name("PCIU"), aml_int(1) /* Device Check */) > - ); > - aml_append(method, > - aml_call2("DVNT", aml_name("PCID"), aml_int(3)/* Eject Request */) > - ); > - } > + /* If bus supports hotplug select it and notify about local events */ > + if (bsel) { > + uint64_t bsel_val = qnum_get_uint(qobject_to(QNum, bsel)); > > - /* Notify about child bus events in any case */ > - if (pcihp_bridge_en) { > - QLIST_FOREACH(sec, &bus->child, sibling) { > - int32_t devfn = sec->parent_dev->devfn; > - > - if (pci_bus_is_root(sec) || pci_bus_is_express(sec)) { > - continue; > - } > - > - aml_append(method, aml_name("^S%.02X.PCNT", devfn)); > + aml_append(method, aml_store(aml_int(bsel_val), aml_name("BNUM"))); > + aml_append(method, aml_call2("DVNT", aml_name("PCIU"), > + aml_int(1))); /* Device Check */ > + aml_append(method, aml_call2("DVNT", aml_name("PCID"), > + aml_int(3))); /* Eject Request */ > + } > + > + /* Notify about child bus events in any case */ > + if (pcihp_bridge_en) { > + QLIST_FOREACH(sec, &bus->child, sibling) { > + int32_t devfn = sec->parent_dev->devfn; > + > + if (pci_bus_is_root(sec) || pci_bus_is_express(sec)) { > + continue; > + } > + > + aml_append(method, aml_name("^S%.02X.PCNT", devfn)); > + } > } > - } > > - if (bsel || pcihp_bridge_en) { > aml_append(parent_scope, method); > } > qobject_unref(bsel); > -- > 2.26.2
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