[PATCH] hw/core: Fix data type in do_nmi()

[Gavin Shan]

object_dynamic_cast() should return machine (or GPIO) state instad of NMI
state in do_nmi(). So it's wrong to convert it to NMI state unconditionally.

This changes the prototype of NMIClass::nmi_monitor_handler() to accept
the parent object of NMI state instead of itself. With this, he parent object
is passed to the function, to avoid potential data corruption.

Signed-off-by: Gavin Shan <gs...@redhat.com>
---
 hw/core/nmi.c              | 8 ++++----
 hw/i386/x86.c              | 2 +-
 hw/misc/macio/gpio.c       | 6 +++---
 hw/ppc/spapr.c             | 2 +-
 hw/s390x/s390-virtio-ccw.c | 2 +-
 include/hw/nmi.h           | 2 +-
 6 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/hw/core/nmi.c b/hw/core/nmi.c
index 481c4b3c7e..554708d0db 100644
--- a/hw/core/nmi.c
+++ b/hw/core/nmi.c
@@ -37,13 +37,13 @@ static void nmi_children(Object *o, struct do_nmi_s *ns);
 static int do_nmi(Object *o, void *opaque)
 {
     struct do_nmi_s *ns = opaque;
-    NMIState *n = (NMIState *) object_dynamic_cast(o, TYPE_NMI);
+    Object *parent = object_dynamic_cast(o, TYPE_NMI);
 
-    if (n) {
-        NMIClass *nc = NMI_GET_CLASS(n);
+    if (parent) {
+        NMIClass *nc = NMI_GET_CLASS(parent);
 
         ns->handled = true;
-        nc->nmi_monitor_handler(n, ns->cpu_index, &ns->err);
+        nc->nmi_monitor_handler(parent, ns->cpu_index, &ns->err);
         if (ns->err) {
             return -1;
         }
diff --git a/hw/i386/x86.c b/hw/i386/x86.c
index 394edc2f72..b98204f104 100644
--- a/hw/i386/x86.c
+++ b/hw/i386/x86.c
@@ -190,7 +190,7 @@ const CPUArchIdList *x86_possible_cpu_arch_ids(MachineState 
*ms)
     return ms->possible_cpus;
 }
 
-static void x86_nmi(NMIState *n, int cpu_index, Error **errp)
+static void x86_nmi(Object *parent, int cpu_index, Error **errp)
 {
     /* cpu index isn't used */
     CPUState *cs;
diff --git a/hw/misc/macio/gpio.c b/hw/misc/macio/gpio.c
index 6cca6b27d6..6b4dfcc188 100644
--- a/hw/misc/macio/gpio.c
+++ b/hw/misc/macio/gpio.c
@@ -196,10 +196,10 @@ static void macio_gpio_reset(DeviceState *dev)
     macio_set_gpio(s, 1, true);
 }
 
-static void macio_gpio_nmi(NMIState *n, int cpu_index, Error **errp)
+static void macio_gpio_nmi(Object *parent, int cpu_index, Error **errp)
 {
-    macio_set_gpio(MACIO_GPIO(n), 9, true);
-    macio_set_gpio(MACIO_GPIO(n), 9, false);
+    macio_set_gpio(MACIO_GPIO(parent), 9, true);
+    macio_set_gpio(MACIO_GPIO(parent), 9, false);
 }
 
 static void macio_gpio_class_init(ObjectClass *oc, void *data)
diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index e076f6023c..3b92e4013d 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -3377,7 +3377,7 @@ void spapr_do_system_reset_on_cpu(CPUState *cs, 
run_on_cpu_data arg)
     ppc_cpu_do_system_reset(cs);
 }
 
-static void spapr_nmi(NMIState *n, int cpu_index, Error **errp)
+static void spapr_nmi(Object *parent, int cpu_index, Error **errp)
 {
     CPUState *cs;
 
diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
index d3edeef0ad..a49952a8b9 100644
--- a/hw/s390x/s390-virtio-ccw.c
+++ b/hw/s390x/s390-virtio-ccw.c
@@ -431,7 +431,7 @@ static void s390_hot_add_cpu(MachineState *machine,
     s390x_new_cpu(object_class_get_name(oc), id, errp);
 }
 
-static void s390_nmi(NMIState *n, int cpu_index, Error **errp)
+static void s390_nmi(Object *parent, int cpu_index, Error **errp)
 {
     CPUState *cs = qemu_get_cpu(cpu_index);
 
diff --git a/include/hw/nmi.h b/include/hw/nmi.h
index a1e128724e..75afa67790 100644
--- a/include/hw/nmi.h
+++ b/include/hw/nmi.h
@@ -38,7 +38,7 @@ typedef struct NMIState NMIState;
 typedef struct NMIClass {
     InterfaceClass parent_class;
 
-    void (*nmi_monitor_handler)(NMIState *n, int cpu_index, Error **errp);
+    void (*nmi_monitor_handler)(Object *parent, int cpu_index, Error **errp);
 } NMIClass;
 
 void nmi_monitor_handle(int cpu_index, Error **errp);
-- 
2.23.0