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

Commit Message

Mark Kanda March 18, 2022, 3:15 p.m. UTC

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 <[e-mail]>
---
 cpu.c | 1 +
 1 file changed, 1 insertion(+)

Comments

Philippe Mathieu-Daudé March 18, 2022, 4:26 p.m. UTC | #1

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 <[e-mail]>
> ---
>   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);
>   }

Mark Kanda March 18, 2022, 5:03 p.m. UTC | #2

On 3/18/2022 11:26 AM, Philippe Mathieu-Daudé wrote:
> 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 <[e-mail]>
>> ---
>>   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.
>

Will fix in v3.

Thanks Philippe,
-Mark

Patch

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);
 
     cpu_list_remove(cpu);
 }