[Qemu-devel] [PATCH] trace: add sanity check

[Anthony Xu <anthony.xu@intel.com>]

If trace backend is set to TRACE_NOP, trace_get_vcpu_event_count
returns 0, cause bitmap_new call abort.

Signed-off-by: Anthony Xu <anthony.xu@intel.com>
---
 qom/cpu.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/qom/cpu.c b/qom/cpu.c
index f02e9c0..f9111a0 100644
--- a/qom/cpu.c
+++ b/qom/cpu.c
@@ -382,6 +382,7 @@ static void cpu_common_unrealizefn(DeviceState *dev, Error **errp)
 
 static void cpu_common_initfn(Object *obj)
 {
+    uint32_t count;
     CPUState *cpu = CPU(obj);
     CPUClass *cc = CPU_GET_CLASS(obj);
 
@@ -396,7 +397,10 @@ static void cpu_common_initfn(Object *obj)
     QTAILQ_INIT(&cpu->breakpoints);
     QTAILQ_INIT(&cpu->watchpoints);
 
-    cpu->trace_dstate = bitmap_new(trace_get_vcpu_event_count());
+    count = trace_get_vcpu_event_count();
+    if (count) {
+        cpu->trace_dstate = bitmap_new(count);
+    }
 
     cpu_exec_initfn(cpu);
 }
-- 
1.8.3.1