Re: [PATCH for-5.1] qapi: Fix visit_type_STRUCT() not to fail for null object

[Markus Armbruster]

Li Qiang <liq3ea@gmail.com> writes:

> Markus Armbruster <armbru@redhat.com> 于2020年7月16日周四 下午11:07写道：
>>
>> To make deallocating partially constructed objects work, the
>> visit_type_STRUCT() need to succeed without doing anything when passed
>> a null object.
>>
>> Commit cdd2b228b9 "qapi: Smooth visitor error checking in generated
>> code" broke that.  To reproduce, run tests/test-qobject-input-visitor
>> with AddressSanitizer:
>>
>>     ==4353==ERROR: LeakSanitizer: detected memory leaks
>>
>>     Direct leak of 16 byte(s) in 1 object(s) allocated from:
>>         #0 0x7f192d0c5d28 in __interceptor_calloc 
>> (/usr/lib/x86_64-linux-gnu/libasan.so.4+0xded28)
>>         #1 0x7f192cd21b10 in g_malloc0 
>> (/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x51b10)
>>         #2 0x556725f6bbee in visit_next_list qapi/qapi-visit-core.c:86
>>         #3 0x556725f49e15 in visit_type_UserDefOneList 
>> tests/test-qapi-visit.c:474
>>         #4 0x556725f4489b in test_visitor_in_fail_struct_in_list 
>> tests/test-qobject-input-visitor.c:1086
>>         #5 0x7f192cd42f29  
>> (/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x72f29)
>>
>>     SUMMARY: AddressSanitizer: 16 byte(s) leaked in 1 allocation(s).
>>
>> Test case /visitor/input/fail/struct-in-list feeds a list with a bad
>> element to the QObject input visitor.  Visiting that element duly
>> fails, and aborts the visit with the list only partially constructed:
>> the faulty object is null.  Cleaning up the partially constructed list
>> visits that null object, fails, and aborts the visit before the list
>> node gets freed.
>>
>> Fix the the generated visit_type_STRUCT() to succeed for null objects.
>>
>> Fixes: cdd2b228b973d2a29edf7696ef6e8b08ec329019
>> Reported-by: Li Qiang <liq3ea@163.com>
>> Signed-off-by: Markus Armbruster <armbru@redhat.com>
>
> Oh, I also sent this too.
> Not matter, just ignore my patch.
>
> Tested-by: Li Qiang <liq3ea@gmail.com>
> Reviewed-by: Li Qiang <liq3ea@gmail.com>

Thanks!

Queued for 5.1.