Re: [PATCH v2 4/5] cpu: Free cpu->cpu_ases in cpu_exec_unrealizefn()

["Philippe Mathieu-Daudé" <philippe.mathieu.daude@gmail.com>]

On 18/3/22 16:15, Mark Kanda wrote:
> vCPU hotunplug related leak reported by Valgrind:
> 
> ==132362== 216 bytes in 1 blocks are definitely lost in loss record 7,119 of 8,549
> ==132362==    at 0x4C3ADBB: calloc (vg_replace_malloc.c:1117)
> ==132362==    by 0x69EE4CD: g_malloc0 (in /usr/lib64/libglib-2.0.so.0.5600.4)
> ==132362==    by 0x7E34AF: cpu_address_space_init (physmem.c:751)
> ==132362==    by 0x45053E: qemu_init_vcpu (cpus.c:635)
> ==132362==    by 0x76B4A7: x86_cpu_realizefn (cpu.c:6520)
> ==132362==    by 0x9343ED: device_set_realized (qdev.c:531)
> ==132362==    by 0x93E26F: property_set_bool (object.c:2273)
> ==132362==    by 0x93C23E: object_property_set (object.c:1408)
> ==132362==    by 0x9406DC: object_property_set_qobject (qom-qobject.c:28)
> ==132362==    by 0x93C5A9: object_property_set_bool (object.c:1477)
> ==132362==    by 0x933C81: qdev_realize (qdev.c:333)
> ==132362==    by 0x455E9A: qdev_device_add_from_qdict (qdev-monitor.c:713)
> 
> Signed-off-by: Mark Kanda <mark.kanda@oracle.com>
> ---
>   cpu.c | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/cpu.c b/cpu.c
> index be1f8b074c..6a3475022f 100644
> --- a/cpu.c
> +++ b/cpu.c
> @@ -173,6 +173,7 @@ void cpu_exec_unrealizefn(CPUState *cpu)
>       if (tcg_enabled()) {
>           tcg_exec_unrealizefn(cpu);
>       }
> +    g_free(cpu->cpu_ases);

There is an API mismatch here. We miss cpu_address_space_destroy().

cpu_exec_unrealizefn() then calls cpu_address_space_destroy(),
and cpu_address_space_destroy() frees cpu_ases.

Otherwise other cpu_address_space_init() calls will keep leaking.

>       cpu_list_remove(cpu);
>   }