Re: [Qemu-block] [Qemu-devel] [PATCH 2/4] tests: fix bdrv-drain leak

[Markus Armbruster]

Max Reitz <address@hidden> writes:

> On 2018-08-13 08:15, Markus Armbruster wrote:
>> Max Reitz <address@hidden> writes:
>> 
>>> On 2018-08-10 08:28, Markus Armbruster wrote:
>>>> Marc-André Lureau <address@hidden> writes:
>>>>
>>>>> Spotted by ASAN:
>>>>>
>>>>> =================================================================
>>>>> ==5378==ERROR: LeakSanitizer: detected memory leaks
>>>>>
>>>>> Direct leak of 65536 byte(s) in 1 object(s) allocated from:
>>>>>     #0 0x7f788f83bc48 in malloc (/lib64/libasan.so.5+0xeec48)
>>>>>     #1 0x7f788c9923c5 in g_malloc (/lib64/libglib-2.0.so.0+0x523c5)
>>>>>     #2 0x5622a1fe37bc in coroutine_trampoline 
>>>>> /home/elmarco/src/qq/util/coroutine-ucontext.c:116
>>>>>     #3 0x7f788a15d75f in __correctly_grouped_prefixwc 
>>>>> (/lib64/libc.so.6+0x4c75f)
>>>>>
>>>>> Signed-off-by: Marc-André Lureau <address@hidden>
>>>>> ---
>>>>>  tests/test-bdrv-drain.c | 1 +
>>>>>  1 file changed, 1 insertion(+)
>>>>>
>>>>> diff --git a/tests/test-bdrv-drain.c b/tests/test-bdrv-drain.c
>>>>> index 17bb8508ae..abc8bbe6f0 100644
>>>>> --- a/tests/test-bdrv-drain.c
>>>>> +++ b/tests/test-bdrv-drain.c
>>>>> @@ -948,6 +948,7 @@ static void coroutine_fn test_co_delete_by_drain(void 
>>>>> *opaque)
>>>>>      }
>>>>>  
>>>>>      dbdd->done = true;
>>>>> +    g_free(buffer);
>>>>>  }
>>>>>  
>>>>>  /**
>>>>
>>>> Screwed up in commit 4c8158e359d.
>>>>
>>>> Max, could the coroutine's stack accomodate the buffer?
>>>
>>> I don't know.  How big is a coroutine's stack?  The buffer size
>>> apparently is 64k.  (Which is my opinion is generally too much to put on
>>> any stack.)
>> 
>> Even in tests?
>
> You have a point, but why do things differently in tests for no reason?
>
> (So I don't leak memory, yeah, sure, but why not write the test in Rust
> then from the start? O:-P)

Only 230 days to April 1st, better hurry.

>>> But why would you want to put it on the stack anyway?  It's not like it
>>> would make the patch any simpler.
>> 
>> If you like the patch as is, go merge it as is :)
>
> W-well, I wasn't CC-d!

I fixed that :)

> I take this as a request to take this one patch from the series and
> merge it into my tree, so I will do that. O:-)

Thanks!