Re: [Qemu-devel] [PATCH v2] net/colo-compare.c: Fix a crash in COLO Primary.

[Jason Wang <jasowang@redhat.com>]

On 2019/5/6 下午6:32, Lukas Straub wrote:
> On Sat, 20 Apr 2019 19:14:25 +0200
> Lukas Straub <lukasstraub2@web.de> wrote:
>
>> From: Lukas Straub <lukasstraub2@web.de>
>> Because event_unhandled_count may be accessed concurrently, it needs
>> to be protected by taking the lock. However the assert is outside the
>> lock, probably causing it to read garbage and aborting Qemu
>> erroneously.
>>
>> The Bug only happens when running Qemu in COLO mode.
>>
>> This Patch fixes the following bug:
>> https://bugs.launchpad.net/qemu/+bug/1824622
>>
>> Signed-off-by: Lukas Straub <lukasstraub2@web.de>
>> ---
>>   net/colo-compare.c | 3 +--
>>   1 file changed, 1 insertion(+), 2 deletions(-)
>>
>> diff --git a/net/colo-compare.c b/net/colo-compare.c
>> index bf10526f05..fcb491121b 100644
>> --- a/net/colo-compare.c
>> +++ b/net/colo-compare.c
>> @@ -813,9 +813,8 @@ static void colo_compare_handle_event(void
>> *opaque) break;
>>       }
>>
>> -    assert(event_unhandled_count > 0);
>> -
>>       qemu_mutex_lock(&event_mtx);
>> +    assert(event_unhandled_count > 0);
>>       event_unhandled_count--;
>>       qemu_cond_broadcast(&event_complete_cond);
>>       qemu_mutex_unlock(&event_mtx);
> Ping.
>
> Regards,
> Lukas Straub


Applied.

Thanks

>