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

[Xu, Anthony]

> Please post steps for reproducing the abort.  I cannot reproduce this
> with qemu-system-x86_64.

The steps to reproduce the issue,

./configure --enable-trace-backend=nop --target-list=x86_64-softmmu

gdb -args ./x86_64-softmmu/qemu-system-x86_64 -bios 
/home/root/guest/seabios.bin -smp 1 -machine q35,accel=kvm
   -m 1G -drive format=raw,file=/home/root/images/centos7.2.img,if=ide,index=0 
-nographic  -nodefaults
  -serial stdio -monitor pty


(gdb) bt
#0  0x00007ffff04e25f7 in raise () from /lib64/libc.so.6
#1  0x00007ffff04e3ce8 in abort () from /lib64/libc.so.6
#2  0x00005555559de905 in bitmap_new (nbits=<optimized out>)
    at /home/root/git/qemu2.git/include/qemu/bitmap.h:96
#3  cpu_common_initfn (obj=0x555556621d30) at qom/cpu.c:399
#4  0x0000555555a11869 in object_init_with_type (obj=0x555556621d30, 
ti=0x55555656bbb0) at qom/object.c:341
#5  0x0000555555a11869 in object_init_with_type (obj=0x555556621d30, 
ti=0x55555656bd30) at qom/object.c:341
#6  0x0000555555a11efc in object_initialize_with_type (address@hidden, 
size=76560,
    address@hidden) at qom/object.c:376
#7  0x0000555555a12061 in object_new_with_type (type=0x55555656bd30) at 
qom/object.c:484
#8  0x0000555555a121c5 in object_new (address@hidden "qemu64-x86_64-cpu")
    at qom/object.c:494
#9  0x00005555557f6e3d in pc_new_cpu (address@hidden "qemu64-x86_64-cpu", 
apic_id=0,
    address@hidden <error_fatal>) at /home/root/git/qemu2.git/hw/i386/pc.c:1101
#10 0x00005555557fa33e in pc_cpus_init (address@hidden)
    at /home/root/git/qemu2.git/hw/i386/pc.c:1184
#11 0x00005555557fe0f6 in pc_q35_init (machine=0x5555565f9690) at 
/home/root/git/qemu2.git/hw/i386/pc_q35.c:121
#12 0x000055555574fbad in main (argc=<optimized out>, argv=<optimized out>, 
envp=<optimized out>) at vl.c:4562


Anthony


> 
> > 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
> >
> >